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

Section 3 - Anatomic Disorders in Sports

Chapter 19 - Bunion deformity in elite athletes

Roger Mann

CHAPTER CONTENTS

  

 

Introduction

  

 

Biomechanics of the first metatarsophalangeal joint

  

 

Types of hallux valgus deformity

  

 

Conservative management

  

 

Physical examination

  

 

Radiographic evaluation

  

 

Decision making

  

 

Surgical procedures

  

 

Postoperative management

  

 

Further reading

Introduction

The hallux valgus deformity in the athlete is no different from the deformity in the nonathlete, but it becomes almost a philosophical question because a foot is to an athlete what a hand is to a musician. Its function must be respected because without it, the athlete, whether a ballerina or lineman, may not be able to perform at an acceptable level. In most cases, unless the athlete's career is jeopardized by his or her hallux valgus deformity, surgical correction probably should not be undertaken for fear that a less than perfect result may jeopardize the athlete's career.

 

Biomechanics of the First Metatarsophalangeal Joint

The main function of the first metatarsophalangeal joint is to stabilize the longitudinal arch through the windlass mechanism. Anatomically the windlass mechanism consists of the plantar fascia inserting into the base of the proximal phalanx via the plantar plate ( Fig. 19-1 ). As the windlass mechanism becomes functional in the last half of stance by the dorsiflexion of the proximal phalanx on the metatarsal head, the metatarsals are depressed as weight is transferred to the toes. The effect of the windlass mechanism is greatest for the hallux and least for the small toe. Secondarily the windlass mechanism elevates the longitudinal arch and aids in inversion of the calcaneus ( Fig. 19-2 ). When a hallux valgus deformity develops and lateral subluxation of the proximal phalanx on the metatarsal head occurs, the sesamoid sling is no longer beneath the first metatarsal head; therefore the windlass mechanism becomes less functional ( Fig. 19-3 ). This is because when dorsiflexion of the phalanx occurs, plantarflexion of the metatarsal and weight transfer to the hallux are diminished resulting in progressive loss of the stability of the longitudinal arch. As it progresses, this loss of stability weakens the medial longitudinal arch, resulting in weight transfer from the first metatarsal to the second. This subsequently can result in excessive fatigue of the foot and possibly callus formation beneath the second metatarsal. This combination of effects results in diminished performance in the athlete, although it could be tolerated by the nonathlete.

 
 

Figure 19-1  Plantar aponeurosis. (A) Cross section. (B) Division of plantar aponeurosis around flexor tendons. (C) Components of plantar pad and its insertion into the base of the phalanx. (D) Extension of toes draws plantar pad over metatarsal head, pushing them into plantarflexion.  From Mann RA: In Coughlin MJ, Mann RA, editors: Surgery of the foot and ankle, ed 7, St Louis, 1999, Mosby.

 



 

 

Figure 19-2  Dynamic function of plantar aponeurosis (A) foot at rest. (B) Dorsiflexion of metatarsophalangeal joints activates windlass mechanism, bringing about elevation of the longitudinal arch, plantarflexion of metatarsal heads, and inversion of heel. This produces stability of the longitudinal arch of the foot.  From Mann RA: In Coughlin MJ, Mann RA, editors: Surgery of the foot and ankle, ed 7, St Louis, 1999, Mosby.

 



 
 

Figure 19-3  Severe hallux valgus deformity with subluxed metatarsophalangeal joint. A deformity of this severity significantly alters the function of the plantar aponeurosis, giving rise to progressive instability of the longitudinal arch. Although this is tolerated by the nonathlete, it may present a significant disability for the athletic individual.

 

 

 

Types of Hallux Valgus Deformity

The hallux valgus deformity can be divided into two basic groups—persons with a congruent joint and those with a noncongruent or subluxed joint. In those with the congruent deformity, the windlass mechanism is not disrupted, and therefore the stability of the foot is not a problem ( Fig. 19-4, A ). In these individuals, the main disability is a large medial eminence, which results in chafing against their shoe. In the noncongruent deformity, there is progressive subluxation of the metatarsophalangeal joint that leads to instability and weight transfer ( Fig. 19-4, B ). In these individuals, the problem is more than an enlarged medial eminence because of the instability that occurs. If the enlarged medial eminence results in sufficient disability for the athlete and he or she can no longer function at the level needed to participate in his or her sport, a hallux valgus repair can be considered.

 

 

Figure 19-4  (A) Radiograph of a congruent metatarsophalangeal joint. There is no lateral subluxation of the proximal phalanx on the metatarsal head. This maintains the function of the plantar aponeurosis and hence the stability of the foot. (B) An incongruent metatarsophalangeal joint has lateral subluxation of the proximal phalanx on the metatarsal head. This creates an unstable situation, progressive in nature, giving rise to decreased function of the plantar aponeurosis and increasing instability of the medial longitudinal arch.

 

 

 

Conservative Management

Conservative management of the athlete with a hallux valgus deformity begins with specifically pinpointing the area of maximal pain because our conservative management must be directed toward relieving that problem. Generally, pain is over the medial eminence and not infrequently where the dorsal medial cutaneous nerve crosses over the bony medial eminence. First, the size of the shoe must be evaluated carefully in relation to the foot. Next, the pattern of the seams that cross over the medial eminence must be evaluated, because, although leather will give way to pressure from the medial eminence, the stitching will not. Sometimes just altering the seams that cross over the bony prominence will result in a great deal of relief. If it appears that the shoe is of adequate size, then the area over the painful spot can be relieved by having the shoe enlarged over this area. This is particularly useful in the athlete who requires a rigid boot, such as a skier, hockey player, rollerblader, and so forth. Even the ballet slipper can be expanded to a certain extent to relieve the pressure over the medial eminence.

The shoe itself could be stiffened to decrease stress across the first metatarsophalangeal joint if the patient's athletic performance would not be diminished. Obviously a lineman can tolerate a stiffer shoe than a ballerina or gymnast.

As a general rule, an orthotic device per se will not do anything to relieve the problems associated with a hallux valgus deformity unless there is sesamoid pain or a transfer lesion beneath the second metatarsophalangeal joint. One must be careful when using an orthotic device because it will take up a certain amount of volume in the shoe and as a result may aggravate the patient's problem rather than relieve it. An orthotic device will not prevent a bunion from occurring.

If the hallux valgus deformity has progressed to the point at which a transfer lesion is occurring beneath the second metatarsal head, then some type of an orthotic device to relieve the pressure will be useful. One must keep in mind, however, that whenever something is added to a shoe it takes up volume; if the shoe is already small, this can aggravate the problem. A change in shoewear may be necessary if an orthotic device is to be used.

Sometimes when an individual has a large medial eminence that is painful, there is tendency to place a pad over the involved area, with the thought that this will relieve pressure, but in actuality doing this increases the pressure. The person should be advised to cut out an area in the pad so that pressure is taken off of the medial eminence rather than applied to it.

 

Physical Examination

The physical examination begins with the patient standing so that the clinician can observe the overall posture of the foot, deformity of the first metatarsophalangeal joint and the alignment of the lesser toes. In athletes, the spectrum of hallux valgus deformities and the shape of the foot are extremely variable. One could be evaluating a National Basketball Association (NBA) player who often has a large, rather flat foot, with multiple lesser-toe deformities as well as the hallux valgus or a ballerina with a moderate to severe hallux valgus deformity associated with multiple lesser toe deformities because of pressure from the dancing shoes. Obviously, there is the entire spectrum in between these types of athletes.

During the physical examination, the patient should be asked to put his or her finger on the area that causes the most pain, and in this way the clinician is directed to the place at which the most attention must be focused.

With the patient sitting, the clinician should determine the range of motion of the ankle, subtalar, and transverse tarsal joint, as well as the posture of the forefoot in relation to the hindfoot. To determine gastrocnemius tightness, the overall tightness of the Achilles tendon should be evaluated with the knee both flexed and extended.

The range of motion of the first metatarsophalangeal joint must be observed carefully, and any crepitation or dorsal impingement should be noted. During this procedure, one is observing the total range of motion, whether or not there is an element of hallux rigidus present, which may be the source of the patient's pain, rather than the deformity itself. One also should see how much passive correction of the deformity can be achieved because this provides insight regarding the degree of correction possible. The clinician palpates the sesamoid area, looking for the possibility that the problem may be due to a fractured or collapsed sesamoid. At times the sesamoid pain is due to the sesamoid's being positioned beneath the cresta ( Fig. 19-5 ). Occasionally, particularly in the ballerina or the younger gymnast, one may encounter avascular necrosis of a sesamoid (usually fibular) as the source of the discomfort. The clinician examines the plantar aspect of the foot, looking for the possibility of transfer lesions, which would occur if the person had an advanced hallux valgus deformity.

 

 

Figure 19-5  Subluxation of the tibial sesamoid beneath the first metatarsal head. As a result of this alignment, there often is pain beneath the metatarsal head because the sesamoid rides against the cresta on the plantar aspect of the metatarsal.

 

 

The lesser toes must be evaluated by checking the range of motion of the metatarsophalangeal joint and the stability of the lesser metatarsophalangeal joints. Sometimes with a severe hallux valgus deformity there can be instability and possible subluxation of the second metatarsophalangeal joint. The presence of hammertoes or mallet toes also must be observed carefully to determine whether or not these are painful.

The neurovascular status of the foot should be checked, but this obviously is rarely a problem in the athletic population.

 

Radiographic Evaluation

Radiographic evaluation is carried out by obtaining weight-bearing anterior-posterior (AP), lateral, and oblique x-rays. For accurate evaluation of a foot, the radiograph must be weight bearing. The measurements obtained are the same as those used for evaluation of other patients with hallux valgus deformity: hallux valgus angle, intermetatarsal angle, joint congruency, distal metatarsal articular angle (DMAA), and evidence of arthrosis ( Fig. 19-6 ). One should determine whether the first metatarsophalangeal joint is congruent or incongruent, identify osteophyte formation around the first metatarsophalangeal joint, observe the sesamoids and their location in relation to the cresta, and observe the alignment of the lesser metatarsophalangeal joints.

 

 

Figure 19-6  Radiographic analysis of a hallux valgus (HV) deformity (A). Hallux valgus angle should be less than 15 degrees, and the intermetatarsal (IM) angle less than 8 degrees. (B)The distal metatarsal articular angle (DMAA) should be less than 10 degrees of lateral deviation. (C) An increased DMAA may result in a clinical situation in which there is a hallux valgus deformity without subluxation of the metatarsophalangeal joint. To correct this problem, a distal metatarsal osteotomy, carrying out a medial closing wedge osteotomy to realign the articular surface, will be necessary. One cannot correct the hallux valgus deformity with an increased DMAA without realigning the metatarsal head because stiffness of the joint will result.

 

 

 

Decision Making

If the decision is made to carry out correction of the hallux valgus deformity, the operative procedure must be selected carefully. In the patient who has primarily an enlarged medial eminence with a congruent metatarsophalangeal joint, the distal soft-tissue procedure alone can provide satisfactory correction. In this situation, the main problem is the enlarged medial eminence, with no subluxation of the metatarsophalangeal joint, so that little or no correction is required. In this case the hallux valgus angle would be less than 30 degrees and the intermetatarsal angle less than 11 degrees. If the intermetatarsal angle is much more than 11 degrees, the possibility of a recurrence will be significant because complete correction of the IM angle probably cannot be achieved. The athlete who is large and has a large foot often has an extremely “stiff” foot. By a stiff foot we mean one that is quite rigid so that the arc of motion of the metatarsophalangeal joints is limited to no more than 45 to 50 degrees. In a foot such as this, obtaining correction of the bunion deformity can be technically difficult; and for the soft-tissue procedure to succeed, an osteotomy must be performed ( Fig. 19-7 ).

 

 

Figure 19-7 (A)  Preoperative and postoperative radiographs demonstrating a satisfactory reduction of a moderate severe hallux valgus deformity using a distal soft-tissue procedure and proximal crescentic osteotomy. (B) A somewhat less than optimal result following a distal soft-tissue procedure and proximal osteotomy in a male with a very “stiff” foot, which made complete reduction of the deformity not possible. The problem with an incomplete correction is that it has a greater possibility of recurrence than one that is completely corrected, and the incompletely reduced sesamoid may be a source of plantar pain.

 

 

The chevron procedure can be used if there is a very large medial eminence, a somewhat larger deformity of the intermetatarsal angle, up to 13 degrees, but the hallux valgus angle should not be more than 30 degrees. The chevron can be used with a mildly subluxed or incongruent joint or may be useful if the patient has an increased DMAA that requires correction. It is important to keep in mind, however, that if the sesamoids have subluxed they often are not corrected by the chevron procedure itself; and, if the sesamoid lies beneath the cresta, this may be a source of pain in the future.

Lastly, the patient with a subluxed metatarsophalangeal joint and an increased intermetatarsal angle will require a correction with a distal soft-tissue procedure and proximal metatarsal osteotomy. In patients with a subluxed metatarsophalangeal joint, complete correction should be obtained; otherwise the metatarsophalangeal joint may be painful because the sesamoids have not been completely reduced, resulting in pain beneath the cresta.

The error that sometimes is made when trying to correct a hallux valgus deformity is to correct the deformity incompletely by using a procedure that does not adequately correct both the bony and the soft-tissue components of the deformity. It is critical that a partial correction be avoided if an early recurrence is to be prevented. This is never a good event for the patient or doctor; but, in the case of the athlete, when there has been downtime from his or her profession and the problem recurs, the result is an extremely difficult situation.

 

Surgical Procedures

It is beyond the scope of this chapter to present in detail surgical procedures that could be used to treat the hallux valgus deformity. Only a brief description of the procedures is discussed, and more details of the surgery can be found in standard foot and ankle textbooks.

The chevron procedure

The chevron procedure, as stated previously, is for the patient who primarily has a congruent metatarsophalangeal joint with a large medial eminence as the main source of discomfort. The chevron procedure should not be used in the athletic population to correct a joint that has more than 1 to 2mm of incongruency (subluxation).

The operation is carried out through a medial approach, which is carried down to the joint capsule. With this type of approach, the dorsomedial cutaneous nerve is not endangered, as it is when a dorsal approach is used. The joint capsule is opened, and the medial eminence then is removed starting at the sagittal sulcus and then angled in a medial direction (not in line with the metatarsal shaft) to obtain as wide a base as possible for the osteotomy site. The center of the head then is identified with a K-wire, after which a chevron cut is made. It is important that the blade not pass too far laterally after it passes the lateral cortex to protect the blood supply laterally. The chevron osteotomy then is displaced in a lateral direction approximately one quarter to one third of the width of the head, depending on the severity of the deformity. If the DMAA is a problem, then possibly a medial closing wedge-type of procedure can be carried out.

The osteotomy site is stabilized with either a pin or screw and the capsule is plicated ( Fig. 19-8 ).

 

 

Figure 19-8  Preoperative and postoperative radiograph demonstrating a chevron procedure.(continued)

 

 

Postoperatively the patient is then kept in a dressing and postoperative shoe for approximately 6 to 8 weeks. If adequate stabilization of the capital fragment has been achieved, the patient probably could start stationary bicycle riding about 2 weeks after the surgical procedure to maintain cardiovascular fitness.

The distal soft-tissue procedure and proximal osteotomy

This procedure is used for the incongruent (subluxed) metatarsophalangeal joint with a hallux valgus deformity of more than 30 degrees and an intermetatarsal angle more than 13 degrees. The principle of this procedure is to carry out a complete distal release of the deformity and then to carry out some type of a proximal metatarsal osteotomy. The type of metatarsal osteotomy used depends on the surgeon. I prefer the proximal crescentic osteotomy; others prefer a proximal chevron or a short oblique. The principle involved is that the intermetatarsal angle must be corrected along with the distal soft-tissue procedure to obtain a correction that will stand the test of time.

The distal soft-tissue procedure is carried out through a dorsal incision in the first webspace, releasing the adductor tendon, the sesamoid sling, and the transverse metatarsal ligament. The lateral joint capsule also is released from its insertion into the metatarsal head.

The second incision is made on the medial side of the metatarsophalangeal joint where it is carried down to the joint capsule. Care is taken to retract the dorsal and plantarmedial cutaneous nerves. A capsulotomy then is performed, and a segment of the joint capsule is removed. The enlarged medial eminence is removed, starting 2mm medial to the sagittal sulcus and removing the fragment in line with the medial aspect of the first metatarsal. This is different from the resection made for the chevron procedure. A third incision is used to carry out the proximal crescentic osteotomy. This is a dorsal approach, starting approximately at the midshaft of the metatarsal and carried just proximal to the metatarsocuneiform joint. The osteotomy site is carried out approximately 1cm distal to the metatarsocuneiform joint, and a screw is used for fixation.

The postoperative immobilization is carried out by using a Kling and adhesive dressing, which holds the toe in proper alignment for a period of 8 weeks ( Fig. 19-9 ). The patient is permitted to ambulate in a postoperative shoe during this period. If one feels that the osteotomy site is sufficiently stable, cardiovascular training on a stationary bicycle can be started after approximately 2 weeks.

 

 

Figure 19-9  Preoperative and postoperative radiograph demonstrating correction following a distal soft-tissue procedure and proximal metatarsal osteotomy.

 

 

I do not feel that a metarsocuneiform joint arthrodesis should be carried out in the active athlete. I think that this procedure carries with it too much morbidity, and the possibility exists of both nonunion at the fusion site and the fusion site spilling over into the second metatarsocuneiform area, which would further stiffen the foot. Although this is tolerated by the nonathlete, I do not think it is a good idea in the athletic population.

At the same time that the hallux valgus deformity is corrected, any existing symptomatic hammertoes can be corrected, if necessary. If there is a dislocation of the second metatarsophalangeal joint, I think that this can be treated with a distal metatarsal osteotomy to decompress the joint and permit adequate reduction of the deformity to occur.

 

Postoperative Management

No matter what bunion procedure is carried out, the foot obviously is weakened by the procedure; and it is important that, after the dressings are removed, the patient undergoes a period of physical therapy to regain the range of motion of the metatarsophalangeal joint. I believe that one should wait at least 1month before allowing the athlete to return to impact-type activities to allow the bones and soft tissues to mature adequately.

 

Further reading

Coughlin MJ: The chevron procedure.  Contemp Orthop  1991; 23(1):45.

Coughlin MJ: Hallux valgus in the athlete.  Sports Med Arthrosc Rev  1994; 2:326.

Coughlin MJ, Mann RA: Adult hallux valgus.   In: Coughlin MJ, Mann RA, Saltzman C, ed. Surgery of the foot and ankle, . ed 7. St Louis: Mosby; 2007.Chap. 6

Mann RA, Rudicel S, Graves SC: Hallux valgus repair utilizing a distal soft tissue procedure and proximal metatarsal osteotomy, a long term follow-up.  J Bone Joint Surg  1992; 74:124.