Porter & Schon: Baxter's The Foot and Ankle in Sport, 2nd ed.

Section 3 - Anatomic Disorders in Sports

Chapter 18 - Great-toe disorders

Robert B. Anderson,Scott B. Shawen

CHAPTER CONTENTS

		Introduction
		Anatomy
		Biomechanics
		Specific entities of the great toe
		Conclusion
		References

Introduction

Injuries to the hallux metatarsophalangeal (MTP) joint are not uncommon, particularly in the running athlete, and may result in chronic pain and deformity. Causes of hallux injuries range from soft-tissue disruption to overuse and degeneration. Trainers and physicians may fail to recognize the potential dysfunction of these injuries, thus providing inadequate care and protection from further injury. Long-term sequelae of even isolated soft-tissue injury include flexor hallucis longus (FHL) tendon tears, hallux valgus or varus, cock-up deformity with interphalangeal (IP) joint contracture, and degenerative joint disease, that is, hallux rigidus.

Clanton and Ford^[1] found that foot injuries rank third behind ankle and knee injuries as the most common time-loss injury among university athletes. Of these foot injuries, a large proportion were sprains of the forefoot and, more specifically, the hallux MTP joint. In our practice, we have seen a number of professional athletes with a broad range of injuries to the great toe and base this chapter on our experiences.

Great-toe injuries can lead to significant functional disability, especially when not recognized early. In the short term, these injuries can result in difficulties with push-off and running. Long-term sequelae include continued difficulty with pain and push-off strength, as well as progressive degeneration. Physicians involved in the treatment of foot and ankle injuries, especially those caring for athletes, must become familiar with the spectrum of injuries about the hallux MTP joint, the conservative and operative treatments for these injuries, and the late sequelae encountered in these athletes.

 

Anatomy

To the surgeon responsible for the care of athletes with great-toe injuries, knowledge of the anatomy of the hallux MTP joint is paramount. In the simplest of terms, the motion of the joint consists of rolling, sliding, and compression. More specifically, the morphology of this joint allows for plantarflexion and dorsiflexion but very limited abduction and adduction. The fact that there is more than one center of motion contradicts the theory of a simple, hinged joint. Instead, the joint is a dynamic acetabulum or “hammock,” as described by Kelikian.^[2] The joint articulation provides little of the overall stability because of the shallow, glenoid-like cavity of the proximal phalanx. Most of the stability comes instead from the capsular-ligamentous-sesamoid complex, which is described in detail later.

There are two sets of ligaments that contribute to the stability of the metatarsal (MT) head as it articulates with the proximal phalanx: the medial and lateral collateral ligaments and the metatarsosesamoid suspensory ligaments.^[3] The fan-shaped medial collateral ligament is composed of the medial MTP ligament and the medial metatarsosesamoid ligament ( Fig. 18-1 ). The lateral collateral ligament is structured in a similar fashion.^[3]

Figure 18-1  Medial diagrammatic representation of first metatarsophalangeal joint.  From Adelaar RS, editor: Disorders of the great toe, Rosemont, IL, 1997, American Academy of Orthopaedic Surgeons.

In addition to the collateral ligaments, the strong, fibrous plantar plate ( see Fig. 18-1 ) also affords structural support. The capsular ligamentous complex of the hallux MTP joint actually is a confluence of structures including the plantar plate, collateral ligaments, the flexor hallucis brevis, the adductor hallucis, and abductor hallucis tendons. This plantar plate is attached firmly to the base of the proximal phalanx and only loosely attached at the MT neck through the capsule.^[4]

The split tendon of the flexor hallucis brevis runs along the plantar aspect of the hallux and envelops the sesamoids before inserting at the base of the proximal phalanx as the capsular-ligamentous complex ( see Fig. 18-1 ). The two sesamoids are united by a thick, intersesamoid ligament and maintain the course of the FHL tendon. Adding to the stability of the hallux MTP joint are three other intrinsic muscles of the great toe. The extensor hallucis brevis originates at the fascia overlying the sinus tarsi and runs obliquely to attach into the extensor mechanism on the dorsum of the MTP joint. It functions primarily as an extensor of the hallux MTP joint. On the plantar aspect, the abductor and adductor hallucis tendons insert on the medial and lateral aspects of the hallux MTP joint, respectively. These tendons blend into the capsular-ligamentous complex, as well as the sesamoids, to provide additional structural support ( Fig. 18-2 ).^[5]

	•	Not a simple, hinged joint.
	•	Most of the stability comes instead from the capsular-ligamentous-sesamoid complex.
	•	Capsular ligamentous complex: plantar plate, collateral ligaments, flexor hallucis brevis, adductor hallucis, and abductor hallucis tendons.
	•	Collateral ligaments have phalangeal and sesamoid insertions.
	•	Split tendon of the flexor hallucis brevis runs along the plantar aspect of the hallux and envelopes the sesamoids before inserting at the base of the proximal phalanx.

 

Figure 18-2  Twenty percent to 30% of the metatarsal head is removed, as well as the exostosis.  From Coughlin MJ, Mann RA, editors: Surgery of the foot and ankle, ed 7, St Louis, 1999, Mosby-Year Book.

 

Biomechanics

The hallux MTP joint lies in an intricate balance of opposing tendons and ligaments. The anatomy outlined previously, especially with regard to the plantar plate, is important when considering the biomechanical demands placed on the first MTP joint. During normal gait, the great toe typically supports twice the load of the lesser toes and accommodates forces reaching 40% to 60% of body weight.^[6]During athletic activity, including jogging and running, the peak forces may approach two to three times body weight, and the forces increase to eightfold when a running jump is performed.^[7]

The range of motion (ROM) in the normal foot has been studied extensively; it is noted to be highly variable and to decrease with aging. In the resting position, the first MTP joint is in a mean resting position of 16 degrees of dorsiflexion. The passive arc of motion was noted by Joseph to be from 3 to 43 degrees of plantarflexion and from 40 to 100 degrees of dorsiflexion.^[8] The mean passive MTP joint dorsiflexion during push-off was 84 degrees. One study found that at least 60 degrees of dorsiflexion is considered normal in barefoot walking on a level surface.^[9] Athletes may accommodate up to 50% reduction in MTP joint motion resulting from acute injury to the plantar plate or hallux rigidus by various gait adjustments such as foot/leg external rotation, shortened stride, and increased ankle, knee, or hip motion.^[4] In addition, a stiff-soled shoe is capable of decreasing MTP joint dorsiflexion to 25 to 30 degrees without significantly affecting gait.^[9]

The effects on the push-off power of the great toe following sesamoidectomy have been studied in vitro by Aper et al.^[10] They confirmed the importance of this seemingly insignificant bone to the function of the toe, particularly in the athlete, in whom even a small loss of power will affect overall performance. The study noted that the isolated excision of the tibial sesamoid equated to an 11% loss of flexor power, there was 19% loss for a fibular sesamoidectomy, and 32% when both are excised.^[10]

	•	Great toe supports twice the weight of each lesser toe.
	•	Hallux dorsiflexion during gait/running is 60 to 84 degrees.
	•	Up to 50% reduction in ROM can be accommodated through gait adjustments such as foot/leg external rotation, shortened stride, and increased ankle, knee, or hip motion.
	•	Sesamoidectomy: tibial excision results in 11% loss of flexor power, fibular 19% loss, and 32% when both are excised.

 

Specific Entities of the Great Toe

Hallux rigidus

Hallux rigidus is defined as a localized degeneration of the hallux MTP joint. It was first described as hallux flexus in 1887 by Davies-Colley.^[11] In his first description of this condition, he discussed a plantarflexed posture of phalanx relative to MT head. The actual term “hallux rigidus” was coined by Cotterill in 1888 and remains the most common term used today.^[12] Numerous papers have theorized the etiology and pathophysiology of hallux rigidus. One such theory is that of metatarsus elevatus, a term describing the dorsiflexed posture of the first ray in relationship to the foot and the subsequent plantarflexed posture of the hallux. This has been discussed by many authors, but the most current data indicate that the elevated posture of the first MT improves after dorsal decompression of the hallux MTP joint. ^{[0130] [0140] [0150] [0160]} Overuse and repetitive dorsiflexion forces, such as those occurring in a runner or kicker, may lead to chondral lesions and other occult injuries^[17] or to osteochondritis dissecans. ^{[0020] [0180] [0190]} It also may result as a sequelae to a turf-toe injury. Anatomic abnormalities that may lead to hallux rigidus include the flat or pronated foot, ^{[0150] [0200] [0210]} a long first MT or hallux,^[21] and a flat MT head.^[22] To this time the true potential etiologies for the development of hallux rigidus remain in question.

Clinical grading from mild to severe (or I, II, and III) has been proposed by many authors. Grading depends on the severity of disease and is based on ROM, pain or crepitus with motion, the size of the dorsal osteophyte on the MT head, the presence of sesamoid involvement, and the radiographic alignment of the hallux (on anterior-posterior [AP] and lateral views). A radiographic classification scheme was created by Hattrup and Johnson in 1988.^[23] Their grade 1 is considered mild; the joint space is maintained and there is minimal spurring. Grade 2 is moderate disease in which the joint space is narrow, bony proliferation is present on the MT head and phalanx, and there is subchondral sclerosis and/or cyst formation. Grade 3 is the severe type, with significant joint space narrowing and extensive bony proliferation that involves the entire periphery and includes loose bodies, a dorsal ossicle, or subchondral cyst formation. A more recent grading scheme, proposed by Coughlin and Shurnas,^[24] combines objective and subjective clinical data with radiographic findings (Grades 0 to 4). Treatment recommendations are made on the basis of grade severity.

Symptoms with which the typical athlete may present include pain that is worse with push-off and more severe after increased activity (i.e., twice-a-day practice regimens), as well as swelling. Although there may be bilateral radiographic involvement, the patient almost always presents with unilateral symptoms. Swelling and the bony prominence itself may interfere with athletic shoewear (especially in soccer and football, sports in which athletes prefer tightly fitting shoewear). A dysesthesia in the dorsomedial cutaneous nerve can result from tight shoewear's impinging on the bony prominence. Occasionally transfer lesions may develop. This presents as metatarsalgia secondary to the lack of hallux dorsiflexion, causing increased pressure on the lateral forefoot.

In treating hallux rigidus in the athlete, one must consider the sporting activity and position played (i.e., a lineman who requires little hallux MTP dorsiflexion vs. a running back or wide receiver), shoewear requirement, and ROM of the entire foot and ankle. Even more minor or early-presenting cases can be problematic because some athletes create more forceful dorsiflexion, which can limit the function of the runner and incapacitate the dancer. Also important is the fact that if a bad joint is provided more motion, it may hurt more and degenerate more quickly.

Nonoperative treatment options include the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and shoewear modifications. Shoes of adequate size and a more full-fitted toe box or increased depth are helpful and can be modified further with a balloon patch over bony prominences. Turf-toe inserts (Springlite, Otto Bock, Minneapolis, MN) that limit dorsiflexion and subsequent dorsal impingement are potentially useful but may limit performance in the elite runner. Rigid rocker soles function in the same manner as semirigid inserts and, although helpful in the general population, are not popular with the athlete because of the increased weight and excessive stiffness. Orthotic devices can unload the hallux MTP joint, but one must remember to increase the shoe size to accommodate for it. Taping techniques can limit dorsiflexion and provide pain relief. Application is the same as that for turf-toe; however, skin problems such as blistering can occur. Steroid injections must be given judiciously and perhaps only for “big game” situations. Repeated injections may accelerate the degenerative process.^[25]

Surgery in the management of hallux rigidus is feasible, and there are many options. The decision to proceed with surgery requires a lengthy discussion with not only the athlete but the trainer and possibly the athlete's agent. It must be emphasized to all parties that this is an arthritic process, there is no “cure,” and there is the potential for a lengthy rehabilitation with incomplete resolution of the symptoms. The physician must determine the following: What is causing the problem? Is it the bony prominence over the MT head and secondary shoewear irritation? Is there limited ROM? Are there biomechanical implications such as poor push-off? Does the athlete suffer from transfer pain issues and other compensatory problems? Lastly, and most concerning, is there the presence of global pain and diffuse arthritis, especially in sesamoid-MT articulation?

The most commonly performed surgical procedure in the management of hallux rigidus is a cheilectomy. This procedure can be defined in general as an excision of an irregular osseous rim that interferes with motion of a joint. In this particular instance it is the removal of the dorsal osteophyte of the MT head. As noted previously, the athlete should be counseled that the underlying condition is degenerative joint disease and that full symptom relief is not realistic. A cheilectomy may prolong the athletic life of the individual but probably does not slow the rate of joint degeneration. As a general rule, the dorsal ridge does not recur, but progressive narrowing of the joint is expected to occur.

Indications for a cheilectomy include a lateral radiograph showing that reasonable space exists in the plantar one half of the MTP joint. There should be an absence of pain or crepitus with midrange motion and no sesamoid-MT pain or disease. This procedure allows for complete relief of dorsal impingement. It increases dorsiflexion by decreasing bulk of joint and subsequently relieving dorsal impingement pain. It also eliminates the source of painful shoe pressure. The true advantage of the cheilectomy is that “no bridges are burned,” and even in unsuccessful cases a salvage procedure is still technically possible.

The technique has been described and popularized by Mann and Clanton.^[26] Their preference is a dorsal longitudinal incision centered over the hallux MTP joint. The joint capsule is incised on either side of the extensor hallucis longus (EHL) tendon and a complete synovectomy is performed. The joint is plantarflexed to permit inspection of the sesamoid articulation. Hamilton^[27] recommends mobilizing the sesamoids by blunt dissection, for they often are anchored by adhesions and limit dorsiflexion even after removal of impinging osteophytes. The amount of bone to be removed from the MT head is dictated by the size of the dorsal exostosis and the degree of articular cartilage destruction. If degeneration of articular cartilage is not significant and the main problem is the dorsal exostosis, then 20% to 30% of the dorsal aspect of the MT head is removed along with the exostosis ( see Fig. 18-2 ).

It is reasonable to be relatively aggressive with this resection, removing up to one third of the dorsal head to achieve improved motion. The cheilectomy should include removal of all osteophytes and a rounding of the MT head. The cheilectomy should achieve a minimum of 70 to 80 degrees of dorsiflexion because approximately one half of this will be lost in the postoperative period as a result of scar formation. It is Mann's recommendation that if insufficient dorsiflexion is achieved after cheilectomy, then a proximal phalangeal osteotomy (Moberg) should be performed as described later.

We have modified the cheilectomy technique through a medial approach. This allows for plantar debridement and release of plantar capsule and adhesions, thus improving dorsiflexion. In addition, the incision avoids the EHL tendon and the potential for tenodesis secondary to scar formation while still providing access to lateral osteophytes. We recommend a two-cut technique to avoid excessive resection of the MT head ( Fig. 18-3 ). The first cut of the saw includes the dorsal exostosis and is made flush with the dorsal diaphysis. The subsequent cut removes the amount of articular surface necessary to achieve the desired dorsiflexion while eliminating the risk of excessive head removal that may jeopardize later arthrodesis.

Figure 18-3  The first cut of the saw includes the dorsal exostosis and is made flush with the dorsal diaphysis. The subsequent cut removes the amount of articular surface necessary to achieve the desired dorsiflexion while eliminating the risk of excessive head removal that may jeopardize later arthrodesis.  From Adelaar RS, editor: Disorders of the great toe, Rosemont, IL, 1997, American Academy of Orthopaedic Surgeons.

Hamilton^[27] describes “radical cheilectomy” similar to the cheilectomy of Mann but also removing the dorsal portion of the base of the proximal phalanx, matching the resection performed on the MT head. This modification serves as an option for dancers with end-stage disease and is similar to the Valenti ^{[0280] [0290]} procedure described later in this chapter.

A cheilectomy affords a fairly rapid postoperative course and return to activity. The patient is allowed to weight bear immediately, typically in a rigid-soled healing sandal. ROM can be initiated by a therapist or trainer as soon as pain allows but not so aggressively as to create wound dehiscence. Sutures generally are removed at 10 days, at which time active and passive ROM should be conducted at least three to four times per day. Close monitoring is required to ensure that the motion within the hallux MTP joint is at a functional level, a minimum of 40 degrees of dorsiflexion. No significant athletic activities generally are allowed for 6 to 8 weeks following a cheilectomy, giving the joint time to mature following surgery. Athletes can continue to train by bicycling, swimming, running in water, and engaging in other activities that avoid significant impact against the MTP joint. The patient should appreciate that swelling may continue for many months but that maximal motion usually is achieved by 3 months.

A number of authors have provided their results of cheilectomy. Mann and Clanton^[26] found that 22 of 31 patients had complete relief, 6 of 31 achieved considerable relief, and ROM increased an average of 20 degrees in 23 of 31 feet. Hattrup and Johnson^[30] reported that 53.4% were satisfactory and 27.6% unsatisfactory. Their failure rate increased from 15% with grade I radiographic changes to 37.5% with grade III changes. They concluded that cheilectomy is the procedure of choice in patients with hallux rigidus and grade I changes. Graves'^[31] experience showed little improvement in motion and stated that satisfaction with cheilectomy was more likely if the patient and the physician had reasonable expectations regarding outcome. He recommended careful patient selection. Myerson agreed that the procedure improves pain, not motion. Easley et al.^[32] reported on 57 patients (75 feet) with greater than 3-year follow-up (average 63 months). Their cheilectomy was performed via a medial approach by a single surgeon. American Orthopaedic Foot and Ankle Society (AOFAS) scores were 45 preoperative, 85 postoperative, and 90% satisfied. The average dorsiflexion improved from 19 degrees preoperative to 39 degrees postoperative. The majority of patients had worsening of radiographic arthritis, but this did not correlate with symptoms. Three patients eventually required an arthrodesis.

Phalangeal osteotomy has been advocated as a useful surgical adjuvant to a cheilectomy. This technique was first proposed by Bonney and Macnab in 1952.^[13] Kessel and Bonney^[19] described its use in 10 adolescents in 1958. Moberg is the name most commonly associated with the procedure, after his case series reported in 1979.^[33] The procedure involves a dorsal closing wedge osteotomy of the proximal third of the proximal phalanx. It relies on the principle that the arc of motion of the hallux MTP joint is translated to plantar aspect of head, thereby increasing functional motion. Basically it creates pseudodorsiflexion, which in turn places less stress on the hallux with push-off. Adequate plantarflexion of the joint is a prerequisite. Thomas and Smith^[34] also found that the procedure appeared to provide dorsal joint space decompression, as well, further relieving stress from the arthritic joint ( Fig. 18-4 ).

Figure 18-4  Space created by dorsiflexion osteotomy of the proximal phalanx.  From Thomas PJ, Smith RWL: Foot Ankle Int 20:4, 1999.

The indications for performing a Moberg osteotomy on the proximal phalanx includes grade I or II hallux rigidus, adolescent hallux rigidus, and the running athlete, perhaps regardless of grade. Most authors now recommend combining the procedure with a dorsal cheilectomy. ^{[0320] [0340] [0350]}

The technique can be performed through a medial or dorsal incision, extending distally from the incision used for the cheilectomy of the hallux MTP joint. It is important to protect the dorsomedial and plantar medial cutaneous nerves to limit paresthesia and the potential for neuritis or neuroma. Longitudinal reflection of soft tissues at the proximal third of the phalanx is performed, maintaining capsular insertion. The FHL and EHL tendons are protected as a dorsal closing wedge osteotomy is performed with a microsagittal saw approximately 3 to 5mm distal to the MTP joint. In the adolescent, it is necessary to avoid the physis. Intraoperative fluoroscopy can be useful in confirming proper position of the osteotomy. The plantar cortex is maintained to allow for a “greenstick” effect with manual closure of the osteotomy. Generally 2 to 6mm of dorsal cortex should be removed, with the actual amount determined by the degree of joint stiffness and amount of plantarflexion of the hallux available. The goal is to obtain 20 to 30 degrees of dorsiflexion relative to the first MT axis. The osteotomy should be stabilized with a suture, K-wire, screw, or staple. If combined with a cheilectomy, stable, internal fixation is mandatory to allow for the initiation of early motion ( Fig. 18-5, A and B ).

Figure 18-5  (A) Dorsal cheilectomy and dorsiflexion osteotomy of the proximal phalanx. (B) The amount of correction after fixation.  From Thomas PJ, Smith RWL: Foot Ankle Int 20:4, 1999.

The postoperative care is similar to that described for an isolated cheilectomy. Immediate full weight bearing is permitted in a hard-soled sandal, with passive dorsiflexion exercises begun at 1 to 2 weeks. In ranging the joint it is important to hold the entire toe as single unit. Plantarflexion exercises are delayed until 3 to 4 weeks postoperative. When a pin is present, removal is performed at 4 to 6 weeks, followed by transition to accommodative shoes.

Published results of the proximal phalanx osteotomy include Moberg's review of older individuals at short follow-up. Eight patients were noted to have satisfactory results. Citron and Neil^[36] evaluated 10 feet in 8 patients with 22-year follow-up (minimum 10 years) and identified 5 symptom free, others with progression of degenerative joint disease (DJD), and one requiring arthrodesis. The average postoperative motion was 43 degrees, 22 degrees being dorsiflexion, with late loss of plantarflexion noted. Asymptomatic compensatory hallux IP flexion contracture often was present. They felt that this osteotomy represented an especially good option in the adolescent. Thomas and Smith^[34] performed the osteotomy with a dorsal cheilectomy in 27 feet, 20 patients. At a follow-up average of 5.2 years, there was a 100% union rate, the average dorsiflexion increased 7 degrees, and 96% of patients were satisfied or satisfied with reservation.

Complications of the Moberg osteotomy include nonunion or malunion, a problem avoided by using internal fixation and “greensticking” the plantar cortex to avoid gross instability. Injury to the FHL and EHL tendons can occur, as can neuritis or neuroma, although the latter typically is transient. The possibility of progressive arthritis of the hallux MTP joint is an outcome that must be discussed with the patient preoperatively. Decreased push-off power can occur and may be of concern in the athlete or dancer.

Salvage for advanced degeneration or for a failed cheilectomy or osteotomy includes either arthrodesis or arthroplasty. Arthrodesis is best avoided in the “sprinting” athlete or dancer. If an arthrodesis must be performed, the toe tip should be at least 10mm off the ground. Failure to meet this requirement will place significant stress on the distal hallux and IP joint. Slight shortening of the hallux also is of benefit, further lessening the potential of the athlete's having to “vault” over the hallux during running activity.

Resection arthroplasty, like that of a Keller, is reserved for the older individual. Capsular interposition is a modification of this procedure devised by Hamilton. ^{[0370] [0380]} In this procedure the proximal 5 to 10mm of proximal phalanx is resected, followed by transection of the extensor hallucis brevis (EHB) tendon and dorsal capsule. This dorsal soft-tissue complex then is advanced to the plantar complex. Some authors release the flexor hallucis brevis (FHB) tendon from the base of the phalanx and suture this to the dorsal capsule. Temporary pin fixation is not necessary ( Fig. 18-6, A and B ). Our own experience with the procedure has noted good relief of pain from dorsal impingement and joint degeneration but a concerning loss of push-off strength. Similarly, the Valenti ^{[0280] [0290]} procedure is a salvage technique in which an angled resection on both sides of the joint is performed, preserving the plantar complex and overall length. The result is a “hinge” effect at the level of the joint ( Fig. 18-7 ).

Figure 18-6  (A) Interposition arthroplasty as described by Hamilton. (B) Pin fixation is not necessary.  From Hamilton WG, Hubbard CE: Foot Ankle Clin 5:663, 2000.

Figure 18-7  Resection of the dorsal metatarsal head as well as dorsal proximal phalanx.  From Coughlin MJ, Mann RA, editors: Surgery of the foot and ankle, ed 7, St Louis, 1999, Mosby-Year Book.

Most recently, an “anchovy” interposition of the hallux MTP joint has been performed in those individuals failing a cheilectomy but needing to maintain hallux MTP motion. Conical resection on both sides of the joint is followed by insertion of a semitendinosus allograft rolled into an “anchovy.” We have used this technique on three patients, one a professional football player, with good short-term results. Coughlin and Shurnas^[39] recently reported on their experience with this technique in seven patients with excellent results. This case series demonstrates that this is a good surgical option in patients who otherwise would be treated with MTP arthrodesis.

Implant arthroplasty has been advocated by some authors; the options described include a silastic double-stem hinge, titanium hemiarthroplasty, or total toe replacement. These implants are unlikely to hold up in the running athlete, and the surgeon is faced with a difficult revision should failure occur. It remains our recommendation to avoid this procedure in the athlete, career or recreational.

Arthroscopic intervention for disorders of the hallux MTP joint has received some attention over recent years. It has been shown to be more of a diagnostic modality than a therapeutic one but may be a reasonable option for the removal of small dorsal osteophytes or loose bodies. It also may be used for debridement of an osteochondral defect on the MT head but is not indicated in advanced hallux rigidus. Van Dijk et al.^[40] performed a prospective study with 24 athletes and found that it was not favorable for hallux rigidus because of “scar fibrosis.”

	•	X-rays: AP and lateral weight-bearing foot.
	•	Multiple etiologies, occult trauma or overuse most common.
	•	Large dorsal soft-tissue and/or bony mass.
	•	Dysesthesia in the dorsomedial cutaneous nerve can result from tight shoewear impinging on the bony prominence.
	•	Nonoperative treatment: NSAIDs, large toe box shoes/balloon expansion, turf-toe plate, rocker bottom shoes.
	•	Surgical treatment: Cheilectomy if plantar joint space intact, Moberg phalanx osteotomy for running athletes, resection arthroplasty in elderly patients, and interpositional arthroplasty for complete joint destruction.

Sesamoid disorders

There are many etiologies for sesamoid pain. The general term “sesamoiditis” is best considered a term for a symptom rather than a diagnosis. This term implies pain in the sesamoid region with negative radiographs and an equivocal magnetic resonance imaging (MRI). It represents a diagnosis of exclusion in which soft-tissue ailments such as bursitis or flexor tendinitis are considered and often is associated with a history of overuse or trauma. ^{[0410] [0420]}

Fracture of the sesamoid, acute or stress, typically involves the tibial hallux sesamoid because of its larger size and greater propensity for weight-bearing forces. The classic radiographic appearance is a transverse fracture line, usually at the midwaist. It also can occur as the result of an MTP dislocation (Jahss Type II).^[5]

Degenerative etiologies for pain in the sesamoid include chondromalacia, osteophytes, impingement, or plantar prominence. These particular problems may occur in an isolated fashion or in association with gout.

Osteochondrosis has an unknown etiology but often is found as a late sequela to a crush injury or stress fracture. Avascular necrosis (AVN) also has been described, most often affecting the fibular hallux sesamoid. Painful fragmentation and cyst formation with flattening of the sesamoid can be seen in either AVN or osteochondrosis, with radiographic changes following symptoms by 6 to 12 months.

Plantar prominence of a hallux sesamoid can occur with bursitis or with an intractable plantar keratosis. Osteomyelitis of the sesamoid can be the result of direct extension from a neuropathic ulcer or puncture wound but is unusual in the athlete.^[43] Tumors of the sesamoid seldom occur but are considered more likely in the fibular side than the tibial.^[5]

Diagnostic evaluation begins with a complete history of the problem. The typical patient will relate pain localized to the plantar hallux MTP joint with weight bearing, worsened with sports and stair climbing, and often with no precipitating event. The clinical examination identifies the specific location of pain and tenderness. Plantarmedial signs relate to disorders of the tibial sesamoid, whereas direct plantar tenderness is indicative of fibular sesamoid pathology. In addition, the presence of swelling, warmth, and erythema should be documented. Joint motion and stability are assessed, noting restriction of motion secondary to pain or associated hallux rigidus. Vertical instability may follow a turf-toe or hyperextension injury. Sesamoid compression that produces pain and grind is consistent with metatarsosesamoid arthritis.

It is mandatory that the radiographic evaluation of sesamoid disorders include standing AP and lateral foot views and axial or tangential sesamoid views. These views are adequate in assessing for focal arthrosis, plantar osteophytes, or bony prominences. The tangential sesamoid view is helpful for identifying fractures of tibial sesamoid. It is helpful to always place a marker (B-B) on the skin overlying the site of tenderness. This simple maneuver helps to differentiate which sesamoid is symptomatic, or may not correlate with a sesamoid location if there is a flexor tendon problem.

A question that often arises is in the differentiation of a fracture versus bipartite sesamoid. A fracture has sharp, irregular borders on both sides of the separation, whereas a bipartite has smooth, cortical edges and a relatively total size larger than that of a single sesamoid. Contralateral AP radiographs may be useful in this differentiation as there is a reported 90% incidence of bilateral occurrence.^[44]

Further diagnostic studies useful in the evaluation of sesamoid disorders include MRI, which helps to localize pathology while differentiating between bone and soft-tissue abnormality. It further assesses sesamoid viability, joint degeneration, and tendon continuity. A readily available tool that is sensitive yet inexpensive is the bone scan. Although there is a reported high rate of false positives, a three-phase study with pinhole images helps to identify the problematic sesamoid. Computed tomography (CT) imaging can be performed to delineate the degree of metatarsosesamoid arthrosis or to assess fracture healing.

The nonoperative treatment of sesamoid disorders is general and begins with the RICE principle of rest, ice, compression, and elevation. Athletic activity and the training regimen are modified. Analgesics and anti-inflammatory medication are useful adjuvants. A boot or cast is applied for the first week in more severe injuries. The cast can include a toe spica extension with the joint in mild plantarflexion, removing stress from the plantarly positioned sesamoids. Weight bearing is permitted as tolerated. Taping of the hallux, as one would for a turf-toe, provides compression and limits movement. This is found to be most helpful in milder injuries. As the patient or player returns to athletic or recreational activity, orthoses and shoewear modifications are mandatory. Off-the-shelf products, such as a Springlite turf-toe plate (Otto Bock, Minneapolis, MN) made of carbon fiber, in full or forefoot lengths, are useful in limiting dorsiflexion stresses. Custom-made devices can be fabricated with a Morton's extension to limit hallux MTP motion. A dancer's pad, MT pad, or arch support placed just proximal to the symptomatic sesamoid will assist in unloading weight-bearing pressures. Furthermore, the shoe itself can be stiffened with a plate incorporated into the sole. The patient should maintain low heel heights to minimize weight-bearing pressures. Turf shoes are modified by removing the cleat under the area of pain. Cortisone and/or anesthetic injections are not advised in any injury. An anesthetic injection alone may be used for localized pain in single-nerve distribution, but we would not completely anesthetize the toe or joint to enable an athlete to return to play.

Surgeries for disorders of the sesamoid are directed to the pathology identified. The first problem to consider is the intractable plantar keratosis (IPK), attributable to the tibial hallux sesamoid. There are instances in which the plantar aspect of the sesamoid will develop a bony prominence, or osteophyte, and an overlying distinct callus will arise. This may occur in the presence of fat atrophy, and there may be an associated bursal component. Failure to improve with an orthosis to relieve pressure from this area may necessitate surgical decompression. The recommendation is for a plantar shaving of the tibial sesamoid via a plantar-medial approach. The periosteum overlying the sesamoid is reflected and the plantar 50% of the sesamoid is resected with a microsagittal saw. The FHL tendon is protected and the joint itself is not entered. The overlying soft tissues then are repaired so that the FHB tendon has been maintained in continuity, thus avoiding the risk of instability. The patient is allowed to weight bear to tolerance in the immediate postoperative period in a protective hard-sole boot or postoperative shoe. Return to regular shoewear and activity is expected over the following 6 to 8 weeks as pain and swelling subside.

Fractures of the sesamoid can occur as acute events or can be stress induced. Acute fractures occur as a result of direct trauma, such as a forceful impact to the forefoot region. Because of its larger size and greater propensity for weight bearing, the tibial sesamoid is more likely to be involved.^[44] These fractures generally heal with limitation of weight-bearing forces by use of such appliances as a cast (with a toe spica extension), boot or postoperative shoe. There have been anecdotal reports of internally fixing these midwaist fractures with small, dual-pitched screws,^[45] but this is technically demanding and may not provide significant benefit over traditional treatment methods.

Stress fractures of the tibial hallux sesamoid have been noted to occur in athletes involved in repetitive-impact exercises, such as long-distance running or aerobics. The diagnosis usually is made months after the onset of discomfort. By then the fracture likely has progressed to an established nonunion. Failure to improve the situation with orthoses designed to relieve pressure and limit excessive dorsiflexion through the joint may necessitate surgical intervention. Bone grafting of these tibial sesamoid nonunions has been performed successfully in an effort to avoid excision and the subsequent risk of losing push-off strength in the hallux.^[10]

Indications for this bone graft procedure include a midwaist fracture location with minimal diastasis, preferably 1 to 2mm. The articular surface of the sesamoid should be free of disease, and the two parts should not demonstrate gross motion between them. A plantarmedial incision is centered at the hallux MTP joint. The capsule is incised along the superior border of the abductor hallucis tendon, and the joint is examined. Should there be cartilage damage on the sesamoid or gross motion between the two halves, then sesamoidectomy is completed. Otherwise, an extra-articular approach to the sesamoid is performed with reflection of overlying periosteum but preserving the FHB tendon. The fibrous material of the nonunion is curettaged back to viable bone surfaces. Care is taken to avoid disruption of the overlying articular surface. Through the capsulotomy, a window is made in the medial cortex of the MT head, and a small amount of cancellous bone is harvested. This graft is packed into the nonunion defect created, and the overlying soft tissues are approximated with absorbable suture. There is no need for internal fixation because the two fragments should remain stable. The capsulotomy is repaired and the wound closed. Postoperatively, the patient is placed in a posterior splint with the distal portion enveloping the hallux itself. At 2 weeks the sutures are removed and a short-leg cast with a toe spica extension is applied. The patient is allowed to weight bear in such a device after 6 weeks, advancing to a shoe protected with a turf-toe plate at 8 weeks. A CT scan at 12 weeks should confirm union, and if accomplished, running is initiated with continued orthotic protection. We previously have reported on this technique in a series of 21 patients, 19 of which were successful.^[46]

Osteochondrosis of the sesamoid may occur with progressive fragmentation. This process may occur insidiously or as the sequela of a stress fracture nonunion^[42] or osteonecrosis. ^{[0470] [0480]} Subchondral cysts may characterize early stages. Patients will present with chronic discomfort worsened by weight-bearing activity. Attempts can be made at nonoperative management using a period of rest and immobilization followed by orthotic management. However, a sesamoidectomy often is necessary in order for a return to recreational activities. ^{[0420] [0470] [0480]}

Sesamoidectomy is the only option for the surgical management of a number of sesamoid disorders, including osteochondrosis, osteomyelitis, advanced degeneration, or the rare tumor. A tibial hallux sesamoidectomy is achieved through a medial or plantarmedial approach, avoiding the plantarmedial digital nerve. The sesamoid can be excised from within the joint or extra-articularly. As discussed for nonunions of the sesamoid, it often is helpful to assess the articular surfaces before excision; this can be accomplished by entering the joint along the superior border of the abductor hallucis tendon. By performing the excision through an extra-articular approach, the overlying FHB tendon can be repaired. A longitudinal incision and reflection of overlying soft tissues (subperiosteal) allows for full exposure of the sesamoid; the bone then can be shelled out circumferentially with a no. 69 Beaver blade. The defect then is repaired side to side with absorbable suture (i.e., 4‐0 Vicryl). The surgeon must be aware of the proximity to the FHL tendon, protecting this structure during the dissection. Although rarely performed because of the risk of residual pain, partial sesamoid excisions can be considered if there is a small proximal or distal fragment. The abductor hallucis tendon can be transferred into large defects created by excision of bipartite or fractured sesamoids. This transfer is performed by dissecting the distal tendon off the capsule at the base of the proximal phalanx. A fasciotomy is performed proximally to allow for rerouting of the tendon to the plantar aspect of the joint, where it is sutured into the defect with absorbable material. A concomitant bunionectomy should be considered if significant hallux valgus is present at the time of tibial hallux sesamoidectomy, because a progressive deformity otherwise may develop.^[49]

When performing a fibular hallux sesamoidectomy, the decision must be made whether to approach from dorsal or plantar surface. A dorsal approach is difficult unless there is a large intermetatarsal 1‐2 angle with lateral subluxation of the sesamoid complex (i.e., bunion/hallux valgus). A longitudinal first webspace incision is used in performing a dorsal-based excision. Following superficial dissection, a laminar spreader placed between the MT heads is helpful. This approach requires the release of the adductor hallucis tendon and other lateral soft-tissue structures. The sesamoid is shelled out of the FHB tendon, taking care to avoid the neurovascular structures plantarly.

The plantar-based approach to fibular sesamoidectomy is preferable in that the soft-tissue structures balancing the hallux MTP joint are not disrupted. In this approach, a curvilinear incision is placed over the palpable fibular sesamoid, but just off of the weight-bearing pad of hallux MTP joint itself. It is necessary to identify and protect the plantarlateral digital nerve ( Fig. 18-8, A and B ). Following the sesamoidectomy, the reflected periosteum and FHB tendon (lateral head) are repaired. Skin closure must carefully approximate the dermal edges to minimize hypertrophic scar formation.  

Figure 18-8  (A) A curvilinear incision is made just lateral to the fibular sesamoid, just off the weight-bearing pad of the hallux metatarsophalangeal joint. (B) Care must be taken to identify and protect the plantarlateral digital nerve.  Drawn by Robert B. Anderson, MD.

Postoperatively soft dressings are applied in such a manner as to maintain plantarflexion and either varus (tibial sesamoidectomy) or valgus (fibular sesamoidectomy). Weight bearing is allowed in a hard-soled sandal or short walker boot for a tibial sesamoidectomy, whereas nonweight-bearing or heel touch protection is recommended for a fibular sesamoidectomy performed through a plantar incision. With the latter, the patient is allowed to begin full weight bearing with the sutures in place at 2 weeks postoperatively. The sutures then are removed 1 week thereafter. Removable bunion splints help to maintain the desired hallux alignment between the second and sixth week. A gradual return to hard-soled shoes follows, using a turf-toe plate in athletic or training shoes.

The results of sesamoidectomy have been provided by a number of authors. Inge and Ferguson^[50] reviewed 41 feet, 25 in which both sesamoids were excised. Complete pain relief was noted in 42%, whereas partial relief was noted in 82% with single sesamoid excision and in 64% of those in whom both sesamoids were excised. Leventen^[51] found complete satisfaction in 18 of 23 sesamoidectomies. Mann et al.^[52] identified 19 of his 21 sesamoidectomies “improved,” but only 50% had complete pain relief and 66% had full motion. In this group, 1 of 13 tibial sesamoidectomies developed hallux valgus, 1 of 8 fibular sesamoidectomies developed hallux varus, and 12 patients developed “weakness.” We assessed 12 patients who underwent a fibular sesamoidectomy via a plantar approach and identified 9 who were very satisfied and 2 who were satisfied. In addition, all would do it again, and 11 of 12 returned to preinjury activity level, citing no complications (for example, scar, neuroma).

Sesamoidectomy is a good procedure that provides reliable results. The surgeon and patient must be aware that there is the potential for biomechanical implications such as the loss of push-off strength. This is especially important in the running athlete or elite dancer and must be discussed before intervening surgically.

	•	X-rays: AP and lateral weight-bearing foot, axial/tangential sesamoid views, skin marker over tenderness, contralateral views.
	•	MRI: differentiates soft-tissue from bone abnormality.
	•	Bone scan: high false-positive rate, use three-phase with pinhole images to isolate problem area.
	•	Fractures: tibial sesamoid more common.
	•	AVN: fibular sesamoid more common.
	•	Nonoperative treatment: NSAIDs, rest, boot/cast in more severe injuries, turf-toe plate, arch support, and/or MT pad.
	•	Surgical treatment: varies depending on diagnosis.

Turf-toe

Since the term “turf-toe” was first used in the literature by Bowers and Martin^[54] in 1976, soft-tissue hyperextension injuries to the first MTP joint have received increasing attention from physicians, trainers, and athletes. Although these injuries have been grouped under the general heading of turf-toe, they actually represent a spectrum of injuries from the mild to the severe. In addition to the straight hyperextension injury of the first MTP joint, we now recognize there are variations that account for injury to specific anatomic structures in the capsular-ligamentous-sesamoid complex.

The true incidence of turf-toe injuries is difficult to quantify. At major universities, these injuries rank number three behind knee and ankle injuries. ^{[0010] [0550]} When Coker et al.^[56] looked at the Arkansas football players, they found ankle injuries to be four times more common than hallux MTP joint injuries; however, the latter were more severe, accounting for a disproportionate number of missed practices and games. Over a 3-year period, 18 of their players had a hallux MTP joint injury, equating to six turf-toe injuries per year. At Rice University, over a 14-year period the average was 4.5 turf-toe injuries per year and included all sports.^[57]

The mechanism of injury can be direct or indirect and requires a basic knowledge of that which is required of the great toe during athletics. When an athlete rises on the ball of the foot for such activities as initiating a jump, blocking, or running, the hallux MTP joint extends upward of 100 degrees. As the proximal phalanx extends, the sesamoids are drawn distally and the more dorsal portion of the MT head articular surface bears most of the load. As this plantar complex attenuates or ruptures, unrestricted dorsiflexion can lead to impaction of the proximal phalanx on the dorsal articular surface of the MT head. This leads to a spectrum of joint injuries from partial tearing of the plantar structures to frank dislocation. The typical scenario leading to this injury in the athlete involves an axial load on a foot fixed in equinus. As an impact or force is placed on the heel, the forefoot progresses into dorsiflexion, creating hyperextension at the hallux MTP joint ( Fig. 18-9 ).

Figure 18-9  An axial load applied to a foot fixed in equinus. As an impact or force is placed on the heel, the forefoot progresses into dorsiflexion, creating hyperextension at the hallux metatarsophalangeal joint.  From Adelaar RS, editor: Disorders of the great toe,Rosemont, IL, 1997, American Academy of Orthopaedic Surgeons.

However, not all turf-toe injuries are purely hyperextension. Numerous variations have been identified. For instance, a valgus component to the hyperextension of the hallux MTP joint results in injury to the plantarmedial ligamentous structures, occasionally to the tibial sesamoid, and the eventual development of a traumatic bunion with contracture of the lateral structures ( Fig. 18-10 ). Douglas et al.^[58]reported the case of a soccer player who sustained a hallux MTP joint injury when he was slide-tackled during practice. He continued to complain of joint instability and he failed conservative measures. MRI and operative findings were consistent with a medial collateral ligament tear, which was repaired.

Figure 18-10  Valgus component to the hyperextension causing injury to the plantarmedial structures, resulting in a traumatic bunion.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:693, 2000.

Like valgus injuries, varus injuries also are rare. Mullis and Miller^[59] reported on a basketball player with an injury to the hallux MTP joint 3 months before presentation. He had difficulty with running and was unable to return to sports participation. On physical examination, he was noted to have significant varus instability of the hallux MTP joint. Surgical findings included a torn conjoined tendon, lateral capsule, and lateral collateral ligament. The plantar structures were noted to be intact. All structures were repaired primarily, and the conjoined tendon was fixed to the base of the proximal phalanx through drill holes.

Over the years many theories have been investigated as causative factors in hallux MTP joint injuries. By far, the two most common etiologic factors mentioned in the literature are the playing surface and flexibility of footwear. In a study by Rodeo et al.,^[60] 80 active professional football players were surveyed, and of those with a turf-toe injury, 83% sustained the initial injury on artificial turf. Bowers and Martin^[54] addressed this relationship by studying the impact of AstroTurf on the West Virginia University's football team. They coined the term “turf-toe” to describe injuries of the hallux MTP joint capsular-ligamentous complex sustained on artificial turf that previously had not been encountered on grass playing surfaces. The AstroTurf was alleged as a causative factor because of the hardness encountered with aging of the surface. However, Clanton and Ford^[1] and others investigated the relationship of turf-toe injuries to aging artificial turf and found no significant correlation. In the three seasons preceding the replacement of the artificial turf in Rice Stadium, there were 13 turf-toe injuries, versus 12 injuries in the three seasons following replacement with a more modern synthetic playing surface. Nigg and Segesser^[61] demonstrated an increased incidence of hallux MTP injuries on artificial turf and attributed this to the enhanced friction inherent in the surface. This may account for the forefoot's becoming fixed to the artificial surface with applied external forces, causing hyperextension and resulting hallux MTP injury.

Bowers and Martin,^[54] as well as Clanton and Ford,^[1] have postulated that the shoe-surface interface most likely is responsible for these injuries. The majority of injuries are encountered on artificial turf in athletes wearing flexible, soccer-style shoes. The abandonment of the traditional grass shoe for the lighter, more flexible, soccer-style shoe seems to have been a major contributing factor in the evolution of the turf-toe problem. The trainers and physicians at Rice University could not recall a single instance of a severe MTP joint sprain occurring in a football player wearing the traditional grass shoe during the 25 years before 1986. This is most likely the result of the steel plate incorporated into the sole of the shoe for the attachment of cleats, which has the secondary benefit of limiting forefoot motion. ^{[0010] [0620] [0630]} In the study by Rodeo et al.,^[60] shoe type was not associated with turf-toe injury in professional football players. However, the number of players wearing traditional grass cleats in this study was small (15 out of 80) and perhaps influenced the outcome.

Some authors have suggested that hallux MTP joint ROM may play a role in turf-toe injuries. Many studies have looked specifically at this factor and concluded that there is no relationship between hallux MTP joint ROM and subsequent turf-toe injury. ^{[0010] [0550] [0600]} However, there may exist a relationship between increased ankle ROM and turf-toe injuries. In the study by Rodeo et al.,^[60] players with a turf-toe injury had mean ankle dorsiflexion of 13.3 degrees, versus 7.9 degrees for uninjured players, a statistically significant difference. It can be postulated that an increased ankle ROM places the hallux MTP joint at risk for hyperextension injuries. Still other causative factors contributing to turf-toe have been suggested. These include player position, weight, age, years of participation, pes planus, hallux interphalangeal degenerative joint disease, and a flattened first MT head. ^{[0010] [0550] [0600]} The data for these variables are largely inconclusive, and it is unlikely that any of these factors play a significant role in the etiology of turf-toe.

Acute injuries to the hallux MTP joint have been classified into one of three general categories ( Table 18-1 ).^[64] Hyperextension injuries usually can be differentiated from hyperflexion injuries by history and physical examination. The clinician should recognize that turf-toe constitutes a broad spectrum of injury with marked variability in the extent of soft-tissue involvement. To plan treatment and predict return to activity, a clinical classification system has been devised ( Table 18-2 ). The mechanism for each of these injuries was discussed previously. At the extremes of hyperextension, frank dislocation of the hallux MTP joint can be seen.

Table 18-1   -- Classification of Turf-Toe

Type of injury	Grade	Description
Hyperextension (turf-toe)	I	Stretching of plantar complex
		Localized tenderness, minimal swelling, no ecchymosis
	II	Partial tear
		Diffuse tenderness, moderate swelling, ecchymosis, restricted movement with pain
	III	Frank tear
		Severe tenderness to palpation, marked swelling and ecchymosis, limited movement with pain, (+) vertical Lachman's if pain allows
		Possible associated injuries
		Medial/lateral injury
		Sesamoid fracture/bipartite diastasis
		Articular cartilage/subchondral bone bruise
		These may represent spontaneously reduced dislocations
Hyperflexion (sand toe)		Hyperflexion injury to hallux MTP or interphalangeal joint
		May also involve injury to additional MTP joints (lesser toes)
Dislocation	I	Dislocation of the hallux with the sesamoids
		No disruption of the intersesamoid ligament
		Frequently irreducible
	IIA	Associated disruption of intersesamoid ligament
		Usually reducible
	IIB	Associated transverse fracture of one or both of the sesamoids
		Usually reducible
	IIC	Complete disruption of intersesamoid ligament, fracture of one of the sesamoids
		Usually reducible

MTP, metatarsophalangeal.

 

 

Table 18-2   -- Clinical Classification System

Grade	Objective findings	Activity level	Treatment
1	Localized plantar or medial tenderness	Continued athletic participation	Symptomatic
	Minimal swelling
	No ecchymosis
2	More diffuse and intense tenderness	Loss of playing time for 3‐14 days	Walking boot and crutches as needed
	Mild to moderate swelling
	Mild to moderate ecchymosis
3	Severe and diffuse tenderness	Loss of playing time for at least 4‐6 weeks	Long-term immobilization in boot or cast versus surgical repair
	Marked swelling
	Moderate to severe ecchymosis
	Range of motion painful and limited

 

To determine the extent of the injured structures in the hallux, the clinician must start by taking a history from the athlete. An exact determination of the events leading to the injury should be sought in each case. Reviewing the videotape of the game sometimes can aid in determining the mechanism. As with most athletic injuries, an examination of the involved extremity shortly after the injury is ideal. The examination should begin with observation of the hallux MTP joint for ecchymosis and swelling, with particular attention paid to the location. Palpation of the dorsal capsule, medial and lateral collateral ligaments and the plantar structures, including the sesamoid complex, should help the physician to elucidate the injured structures. The hallux MTP joint then can be placed through an ROM and compared with the opposite side. Abnormalities such as a mechanical block, hypermobility resulting from a plantar plate tear, or gross instability can be appreciated. Varus and valgus stress testing then should be performed and also compared with the contralateral side. A dorsoplantar drawer test (Lachman) of the MTP joint will test the integrity of the plantar capsular-ligamentous complex. Plantarflexion and dorsiflexion of the hallux MTP joint against resistance should be performed to check the integrity of the flexor and extensor tendons of the hallux. In reality, this detailed examination can be difficult in the acutely injured athlete because of pain.

Following clinical evaluation, radiographic analysis is mandatory for all hyperextension injuries. In addition to the soft-tissue disruption, bony abnormalities may include capsular avulsions, sesamoid fractures, impaction fractures, diastasis of bipartite sesamoids, and proximal migration of the sesamoids. Recommended radiographs include a weight-bearing AP and lateral and a sesamoid axial view. A comparison AP view of the opposite foot is helpful. Prieskorn et al.^[65] found that patients with a complete plantar plate rupture had proximal migration of the sesamoids. The easiest way to evaluate the radiograph is to compare the distal aspect of the sesamoid-to-joint distance on the affected side with the unaffected side. The difference between sides should be within 3.0mm (tibial) and 2.7mm (fibular) 99.7% (3 SD) of the time. Looking at absolute numbers, if there was greater than 10.4mm from the distal tip of the tibial sesamoid to the joint and greater than 13.3mm from the distal tip of the fibular sesamoid to the joint, then there was a 99.7% chance of plantar plate rupture.

In addition to the standard views, special views and studies may be indicated, depending on a clinician's suspicion. Rodeo et al.^[66] have suggested a forced dorsiflexion lateral view ( Fig. 18-11, A and B ), which may delineate joint subluxation, sesamoid migration, or separation of a bipartite sesamoid. Stress radiographs may help to define complete disruption of the medial or lateral capsular-ligamentous complex. In addition, two oblique radiographs may be obtained. Other studies previously used in the diagnosis of turf-toe injuries include bone scintigraphy to rule out stress fractures or arthrography to document capsular tears. However, in our experience, MRI best defines soft-tissue injury and the presence of osseous and articular damage ( Fig. 18-12 ). The use of a 1.5-Tesla MRI scanner with paired 3-inch–round phased array surface coils can be used to obtain proton density and T2-weighted images. These images, obtained in the coronal, axial, and sagittal planes, provide anatomic detail of the nature and extent of soft-tissue injuries in acute turf-toe injuries.^[65] We are liberal in performing this test because it assists in grading, identifies subtle injuries, provides timely decision making, and helps to formulate a prognosis.

Figure 18-11  (A) Normal dorsiflexion lateral. (B) Forced dorsiflexion lateral demonstrating proximal migration of the sesamoids.

 

Figure 18-12  Magnetic resonance imaging notes injury to bones and soft tissue.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:698, 2000.

The treatment of all grades of turf-toe injuries in early stages is similar.^[67] Principles, which apply to most acute sprains of the musculoskeletal system, apply to the hallux MTP joint as well. Once the injury is recognized, immediate application of ice with a compressive-type dressing may aid in reducing swelling. Taping of the great toe in this acute stage is not recommended because swelling could lead to compromise of circulation. Clanton and Ford^[1] suggest using the RICE formula of rest, ice, compression, and elevation. In addition, an NSAID may be prescribed. In some cases, a walker boot or a short-leg cast with a toe spica in slight plantarflexion may be helpful to alleviate symptoms during the first week ( Fig. 18-13 ). Early joint motion may begin within 3 to 5 days after initial injury if symptoms permit. At this point, a severity grading must be applied so the athlete can be advised regarding prognosis and the time necessary for rehabilitation before a return to competition.

Figure 18-13  Example of a short-let walking cast with toe spica extension in slight plantarflexion.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:699, 2000.

Athletes with a grade 1 injury usually are able to return to their sport with little or no loss of playing time. These athletes may benefit from taping of the great toe, as well as shoewear modifications. The taping is designed to restrict hyperextension of the hallux MTP joint. Another technique used to restrict forefoot motion is the placement of an insole that includes a spring carbon-fiber steel plate in the forefoot region of the shoe. A custom insole with a Morton's extension may be better suited for the high-performance athlete but generally requires a longer shoe with a wider toe box. Factory made turf-toe shoes are available that restrict forefoot bend, but most running athletes resist this treatment because of a perceived loss of mobility.

Grade 2 injuries usually result in loss of playing time ranging from 3 to 14 days, followed by the same modalities as mentioned previously. The grade 3 injuries may result in loss of playing time of at least 4 to 6 weeks, often requiring long-term immobilization and examinations weekly. In athletes who experience continued swelling and edema, modalities such as whirlpool and ultrasound with cold compression may be used as adjuncts to traditional therapy.^[68] In general, return to play is dictated by symptoms, preferably with the athlete demonstrating 50 to 60 degrees of painless passive dorsiflexion. However, this return to athletics is individualized, dependent on the player's position, the level of discomfort, and healing potential.

There is a paucity of literature on the surgical management of hallux MTP joint injuries. This stems from the general notion that surgical management rarely is indicated in the treatment of this disorder. However, when an athlete fails to respond to conservative modalities, the treating physician should be suspicious for pathology that requires surgical intervention. Indications for surgery include a cartilage flap or loose body within the hallux MTP joint, acute sesamoid fracture, separation of a bipartite sesamoid, proximal migration of the sesamoids, evidence of gross instability resulting in persistent pain or synovitis, and hallux rigidus.

The study by Rodeo et al.^[63] revealed that four athletes were noted to have diastasis of a bipartite tibial sesamoid and underwent excision of the distal fragment with repair of the capsule. One of these four athletes underwent acute excision, and the other three after failed conservative management. All of these players returned to their preinjury level of competition.

Our own experience in the repair or reconstruction of hyperextension injuries has been derived from a number of individuals who had sustained a turf-toe and subsequently were unable to perform athletically at their preinjury level. These athletes often complained of pain with running activity, along with the inability to cut from side to side. Clinical findings included malalignment of the hallux, traumatic and progressive bunion deformity, clawing of the great toe, diminished flexor strength, generalized joint synovitis, and advanced degeneration of the joint. Radiographic analysis often showed proximal migration of one or both sesamoids and cases of progressive diastasis of bipartite sesamoids ( Fig. 18-14 ). MRI performed confirmed pathology through the plantar complex of this joint, often associated with injuries to the joint surface or FHL tendon. All the cases of proximal sesamoid migration associated with hyperextension injury have been associated with distal rupture. It appears that the sesamoids rupture distally and migrate proximally because of the preservation of the flexor tendons, along with the abductor and adductor tendons, and their ability to retract.

Figure 18-14  (A) Anterior-posterior (AP) radiographs of a professional football player following a turf-toe injury. Note the diastasis of the tibial sesamoid. (B) AP radiograph repeated 1 year later demonstrating progression of diastasis, which was associated with early clawing of the toe.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:701, 2000.

Our surgical experience with this injury has included 12 professional and collegiate athletes. Five surgeries were performed acutely for proximal migration or diastasis of a bipartite sesamoid, whereas seven were performed for chronic injuries, which included two traumatic bunions and one hallux varus deformity.

In the acute repair and reconstruction of these plantar complex injuries, exposure can be obtained through a medial, medial and plantar, or J-incision technique. Care is taken to avoid injury to the plantar medial digital nerve as it courses over the region at the tibial sesamoid. Plantarflexion of the joint can assist with plantar exposure of the joint. Once the defect has been identified in the plantar complex distal to the sesamoids, advancement and primary repair can be achieved with nonabsorbable sutures. Typically, sutures are placed into remnants of soft tissue on the base of the proximal phalanx. If found inadequate, then suture anchors or drill holes in the plantar lip of the proximal phalanx may be used.

In cases of a progressive diastasis of a bipartite sesamoid, it is our recommendation to preserve one pole of the sesamoid if possible. Typically, the distal pole is excised and soft tissues are repaired through drill holes in the remaining proximal pole. Should both poles of this sesamoid be damaged, or if fragmentation of the sesamoid is encountered, complete sesamoidectomy may be necessary. In this instance, a large soft-tissue defect will result, leading to an incompetent FHB and potential loss of plantar restraints. We recommend that an abductor hallucis tendon transfer be performed ( Fig. 18-15 ). This transfer will act not only dynamically, helping to restore flexion power to the hallux, but also as a plantar restraint to dorsiflexion forces.

Figure 18-15  Technique of abductor hallucis tendon transfer for reconstruction of hallux metatarsophalangeal joint. (A) Abductor hallucis tendon dissected from underlying capsule and immobilized proximally. (B) Plantar defect following sesamoid excision. (C) Transfer of abductor hallucis tendon completed with attachment to proximal phalanx.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:703, 2000.

There are situations in which late reconstruction of these injuries is necessary, for example, when the athlete continues to perform despite injury or when the injury has been inadequately treated and protected. In these situations the sesamoids may migrate well proximal, a problem often associated with hallux valgus, varus, or cock-up deformity. Reconstruction may include attempts at distal advancement of the sesamoids with soft-tissue reconstruction. This requires significant mobilization of the soft tissues proximal to the sesamoids, necessitating fasciotomies or fractional lengthenings of the flexor hallucis brevis and abductor hallucis muscles. Joint debridement and cheilectomy may be necessary in cases of associated synovitis and osteochondral injury. Reconstruction of traumatic bunion deformities necessitates not only reconstruction of the plantar medial soft tissues but also a release of the lateral soft-tissue contractures.

The reconstruction of the claw toe deformity that occurs as a late sequela to hyperextension injuries is difficult. If the deformity is passively correctable at both the hallux MTP and IP joint levels, a flexor-to-extensor tendon transfer can be performed successfully. This transfer can be achieved either by splitting the flexor tendon and reapproximating dorsally into the extensor hood, as described by Girdlestone-Taylor, or by transferring directly through a drill hole into the base of the proximal phalanx ( Fig. 18-16 ). Occasionally, a claw toe deformity will include a fixed contracture of the IP joint. This situation can be addressed through hallux IP arthrodesis and a flexor-to-extensor tendon transfer, as described previously.

Figure 18-16  (A-D) Technique for reconstruction of a claw-toe deformity that is passively correctable.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:706, 2000.

The postoperative management of athletes undergoing surgical reconstruction of hyperextension injuries is difficult because of the delicate balance between soft-tissue protection and early ROM. First, it is important to avoid placing the hallux in greater than 10 degrees of plantarflexion, either through surgical reconstruction techniques or with postoperative external immobilization modes. Excessive plantarflexion to this joint may become fixed and difficult to compensate for in the running athlete. Our protocol includes external immobilization in approximately 5 to 10 degrees of plantarflexion for a period of 7 to 10 days. At that time the athlete is initiated on protective, passive plantarflexion under the direct guidance of the athletic trainer or physical therapist. We avoid active and passive dorsiflexion and active plantarflexion maneuvers. When at rest, the toe is protected with a bunion splint using a plantar Velcro restraint and a removable posterior splint or cast boot. Nonweight-bearing ambulation is continued for a period of 4 weeks. ROM of the hallux is increased gradually at that time, along with protected ambulation in a cast boot. At 2 months postoperative, the patient is placed into an accommodative athletic shoe with the protection of an insole plate that limits dorsiflexion. Active ROM is instituted, and by 3 to 4 months postoperative, the patient is allowed to return to contact activity with the continued protection of taping techniques and shoewear modifications. We have found that it takes approximately 6 to 12 months before the athlete can perform at the preinjury level of function.

Late sequelae of turf-toe injuries may occur after conservative management or, less commonly, after surgical treatment has been rendered. Coker et al.^[55] reported on nine athletes who had sustained a hyperextension injury. The most commonly reported late sequelae were joint stiffness and pain with athletic activity. Clanton et al.,^[57] in their study of 20 athletes with turf-toe injury and 5 years of follow-up, noted a 50% incidence of persistent symptoms. Other late sequelae include cock-up deformity, hallux valgus, hallux rigidus, arthrofibrosis, loose bodies, and loss of push-off strength.

	•	Turf-toe constitutes a broad spectrum of injury with marked variability in the extent of soft-tissue involvement.
	•	Hyperextension injury to the plantar capsular-ligamentous-sesamoid complex.
	•	Can have varus or valgus component to injury pattern.
	•	Note ecchymosis, hypermobility, and varus/valgus on physical examination.
	•	X-rays: weight-bearing AP and lateral with contralateral views, sesamoid view, forced dorsiflexion lateral with contralateral view. Note sesamoid-to-joint distance.
	•	MRI: coronal, axial, and sagittal planes. May identify subtle injuries.
	•	Treatment: rest, ice, compression, elevation. Return to activity depends on severity of injury (see Table 18-2 ).
	•	Shoe modifications and/or turf-toe insert to prevent hallux hyperextension.
	•	Surgical indications include a cartilage flap or loose body within the hallux MTP joint, sesamoid fracture, separation of a bipartite sesamoid, proximal migration of the sesamoids, evidence of gross instability resulting in persistent pain or synovitis, and hallux rigidus.

Dislocations of the Hallux MTP joint

Frank dislocation of the hallux MTP joint most likely represents the extreme along the spectrum of hyperextension injuries. Dislocation in the dorsal direction is by far most common, yet plantar and lateral dislocations have been described. Jahss classified dislocation of the hallux MTP joint into two types.^[69]

In the type I dislocation, the MT head buttonholes through the weak capsular tissue proximal to the sesamoids. The distal plantar plate, sesamoids, and intersesamoid ligament remain intact and attached to the phalanx distally. This intact complex comes to lie just dorsal to the MT head, with the flexor hallucis brevis tendon dorsally translated. A closed reduction in the emergency department always should be attempted under local anesthesia. However, this injury typically is irreducible and requires an open reduction of the MTP joint through a dorsal approach.^[70] If reduction cannot be obtained by reducing the sesamoids with an elevator, release of the adductor tendon and the deep transverse MT ligament or intersesamoid ligament may be required.^[71] If the joint is unstable after reduction, stabilization with a Kirschner wire is recommended; this can be removed after 3 to 4 weeks.^[71]

Type II injuries are subclassified into types IIA and IIB ( Fig. 18-17 ). In type IIA dislocations, the intersesamoid ligament is disrupted and radiographs reveal widening of the space between sesamoids and dislocation of the MT head into or through the sesamoid split. Type IIB injuries produce a transverse fracture through one (usually tibial) or both sesamoids. In the situation of a single sesamoid fracture, the proximal fragment remains aligned with the intact sesamoid, and the distal fragment often becomes a loose body in the joint, usually requiring surgical removal. In addition to these types described by Jahss,^[69] Copeland and Kanat^[72] defined a type IIC that is a combination of both IIA and IIB. The type IIC dislocation represents both a complete disruption of the intersesamoid ligament and a transverse fracture of either sesamoid ( Table 18-3 ).

Figure 18-17  Dislocations. (A and B) Anterior-posterior (AP) and lateral radiograph of a type IIA hallux metatarsophalangeal (MTP) dislocation. (C and D) AP and lateral radiograph of a type IIB hallux MTP dislocation.  From Watson TS, Anderson RB, Davis WH: Foot Ankle Clin 5:710, 2000.

Table 18-3   -- Radiographic Findings in Hallux Metatarsophalangeal Joint Dislocations

Dislocation type	Radiographic findings
I	No widening between sesamoids on AP view
IIA	Wide separation between sesamoids on AP view
IIB	Fracture of sesamoid (usually tibial)
IIC	Combination of type IIA and type IIB

AP, Anterior-posterior.

 

 

Differentiating between type I and type II dislocations is important because operative intervention typically is required for type I but not for type II dislocations. The general reduction maneuver is performed by placing gentle distraction with hyperextension on the MTP joint. If the joint is reducible, it typically is stable and is placed into a cast or hard-soled shoe for 3 to 4 weeks. A postreduction radiograph is required to confirm an anatomic reduction or to rule out the presence of any loose bodies.^[73]

Occasionally, gross instability will follow a type II dislocation, particularly when a fracture of the sesamoid(s) has occurred. In this instance, the patient will experience pain with push-off and hallux rigidus type symptoms. A positive drawer sign is elicited, along with signs of generalized synovitis. Surgical correction in this setting includes plantar reconstruction to restore a restraint to dorsiflexion forces. Specifically, sesamoidectomy and abductor hallucis tendon transfer may be indicated. In the case of late clawing, an FHL transfer should be considered, as described previously.

	•	Most extreme hyperextension injury with two main types (see Table 18-1 ).
	•	Type I: MT head buttonholes through intact plantar complex and likely irreducible. Surgical intervention to release blocks to reduction. Usually stable but may require K-wire fixation.
	•	Type II: three subtypes with injury to the plantar complex. Usually reducible, may require delayed reconstruction.

Hyperflexion injuries of the hallux MTP joint

As stated previously, turf-toe injuries involve primarily a hyperextension injury to the hallux MTP joint with a possible varus or, more commonly, a valgus component. Rodeo et al.,^[60] in their report on turf-toe injuries in professional football players, concluded that 12% of the players had a hyperflexion injury to this joint. Hyperflexion injuries clearly do not fit into the classification system for turf-toe. In fact, the mechanism and pathology are much different, and these injuries should not be grouped together.

Frey et al.^[74] reported on a series of professional beach volleyball players with a hyperplantarflexion injury to the hallux MTP joint, an injury referred to as “sand toe.” This injury can result in significant functional disability noted with push-off, forward drive, running, and jumping. Although described in volleyball players, it also can be seen in football players, soccer players, and dancers.

The hyperflexion injury occurs when the weight of the body lands on a neutral or slightly plantarflexed hallux MTP joint. Frey et al.^[74] reported on 12 volleyball players, 11 of whom had sustained an injury to the hallux MTP joint. The treatment for this injury mainly is conservative: taping, rest, ice, and NSAIDs. Once the inflammation has resolved, the athlete should undergo a rehabilitation program that includes strengthening of the intrinsic and extrinsic muscles of the foot. However, the time to recovery was, on average, 6 months (range 1‐12 months). The most common problem after injury was loss of dorsiflexion of 25% to 50% at the hallux MTP joint, as well as residual pain. No toe deformities were noted. The authors attribute the loss of motion to capsular damage, synovitis, and arthrofibrosis. Whether or not arthroscopic debridement would benefit these athletes remains a question for future study.

	•	Different mechanism and injury pattern than turf-toe.
	•	Often referred to as sand toe.
	•	Treatment normally nonoperative with rest, ice, and NSAIDs.
	•	Rehabilitation after inflammation subsides with intrinsic/extrinsic strengthening.
	•	Motion loss of from 25% to 50% is common.

 

Conclusion

The great toe and its articulations are of paramount importance to the athlete. Great forces are transferred through this area with running, jumping, changing direction, and landing. Minor injuries can affect the ability even to walk or stand. A complete knowledge of the anatomy, forces involved, and treatment regimens are paramount when treating patients with these disorders.

 

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