Robert T Sullivan and William E. Garrett
DEFINITION
Groin injuries are common among athletes, accounting for 2% to 5% of all athletic injuries.12
A broad spectrum of pathology can cause groin pain in the athlete, and the differential diagnosis is critical.
Adductor longus–related pain is the most common entity, particularly in athletes participating in kicking sports, such as soccer, and in sports requiring rapid directional changes such as ice hockey and American football.6,7,12,13
Most acute adductor-related groin pain represents strain at the muscle–tendon junction. Although rare, complete avulsions of the adductor longus origin from the pubis can occur.
Chronic adductor pain typically occurs as an isolated enthesopathy or in concert with athletic pubalgia or pre-hernia complex.
ANATOMY
The adductor longus is a large, fan-shaped muscle that originates from the anteromedial aspect of the superior pubic ramus just inferior to the pubic tubercle and inserts on the linea aspera of the femur.
Innervated by the anterior division of the obturator nerve, the origin of the adductor longus consists of direct attachment of both muscle fibers and tendon to the pubis. The proximal tendon has a narrow cross-sectional area.12
The proximal tendon is readily identified on the anterior surface of the muscle with an oblique muscle–tendon junction. The proximal posterior surface usually is entirely muscular in origin.13
A common anomaly is muscle fibers forming the lateral 5 to 11 mm of the anterior origin (FIG 1).13
In maturity, the fibrocartilage of the symphysis pubis develops a small, central fluid-filled cavity or cleft.This cleft manifests as a central focus of high signal intensity at T2weighted and fat-suppressed short T1 inversion recovery (STIR) imaging.3
FIG 1 • Muscle fibers forming the most lateral aspect of the adductor longus origin.
PATHOGENESIS
The pathogenesis of chronic adductor strains and frequently associated sports hernias or athletic pubalgia is poorly understood.
The problem usually is seen in athletes using powerful and ballistic muscle action involving a rapid change from a trunk rotated posteriorly to the plant foot with simultaneous hip extension and abduction followed by a sudden anterior trunk rotation with hip flexion and adduction.
Examples are an in-step kick in soccer or a fast gait in hockey when the trailing leg is pulled forward, where these actions create strong muscle activity around the lower abdominal muscles and hip adductors and flexors.
Many of these conditions are chronic or acute on chronic.
The possibility of a subtle degree of pelvic instability has been considered, but it is difficult to prove.2–4
Hip adductor involvement is more likely an abnormality at the insertion than a chronic tendinitis or tendinosis.2–4
NATURAL HISTORY
Acute adductor strains at the musculotendinous junction, like other muscle strain injuries, vary considerably in time to recovery based on the severity of the injury. These are almost always managed without surgery.
Prior adductor strain has been shown to be a significant risk factor for injury.14
An adductor-to-abductor muscle strength ratio of less than 80% is predictive for a future adductor strain as well. Preseason hip strengthening regimens can lower the incidence of adductor strains.14,15
In the rare instance of a complete adductor longus avulsion, nonoperative management is preferred.11
Chronic adductor pain presenting as an enthesopathy may occur simultaneously with athletic pubalgia or may follow an acute strain. Enthesopathy can lead to resistant, chronic groin pain, warranting operative intervention.
PATIENT HISTORY AND PHYSICAL FINDINGS
The diagnosis of an acute adductor strain is relatively straightforward, because the athlete typically presents with a sudden injury to the groin incurred during athletic competition.
There is tenderness to palpation at the muscle tendon junction. This pain is exacerbated with resisted adduction and passive abduction. Imaging rarely is required for acute strains, but is more commonly obtained for professional athletes.
In the setting of a more severe acute injury or avulsion, edema and ecchymosis are present and a defect may be palpated.
The diagnosis of chronic groin pain is not as straightforward because of the broad spectrum of clinical entities that can cause pain in this region and their similar presentations.
There is no current diagnostic gold standard for chronic groin pain.
The differential diagnosis is critical owing to the possibility of other serious disorders; thus, a comprehensive history and physical is warranted in the patient with chronic groin pain.
The physical findings of chronic adductor pain are similar findings to those of an acute strain, but the examiner is more likely to elicit pain with palpation of the pubic symphysis and is more reliant on imaging, coupled with the examination, for a definitive diagnosis.
Involvement of the symphysis pubis detected by physical and even radiographic examination is common.
Chronic adductor-related pain often occurs in conjunction with athletic pubalgia. Sports hernias can present with complaints of vague and migratory lower abdominal pain radiating to the medial thigh.
Sports hernia findings are pain with a sit-up maneuver or resisted internal rotation of a flexed hip. Tenderness to palpation is found above the inguinal ligament and superior to the pubic tubercle. Tenderness may be more focal, involving the external inguinal ring without a palpable hernia or in the vicinity of the conjoint tendon.
Physical examination should include.
Palpation of the adductor longus. Focal tenderness suggests adductor-realated groin pain. A palpable defect implies adductor avulsion.
Squeeze test. The presence or absence of pain is noted. Strength is graded as follows: mild—minimal loss of strength; moderate—clear loss of strength; severe—complete loss of strength. Pain with or without a strength deficit implies adductor-related groin pain.
Passive stretch of adductors. Pain localized to the adductor implies adductor-related groin pain.
Palpation of external inguinal ring. Pain in the absence of a palpable hernia implies a sports hernia.
Sit-up against resistance. Adductor pain implies a concomitant or isolated sports hernia.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Imaging studies are most effective when selected on the basis of a thorough history and physical examination.
MRI is the imaging modality of choice to evaluate chronic adductor-related pain.
Muscle strains have high T2 signal at the muscle–tendon junction, which can extend along the epimysium.
Enthesopathy, an overuse inury, reveals signal change within the adductor origin and, often, the pubic marrow.
We believe that osteitis pubis, ie, marrow changes within the pubis, is a radiologic sign rather than a diagnosis, because these changes are most often present in the setting of adductor-related symptoms.
Robinson demonstrated that patient symptoms and MRI abnormalities within the pubis correlated significantly and reproducibly with symptomatic adductor enthesopathy or chronic myotendinous strain.2,10Thus, pubic marrow changes should alert the clinician to consider an adductor or lower abdominal wall injury.9,10
Additionally, Cunningham4 demonstrated pubic marrow changes are frequently associated with adductor injury, but adductor enthesopathy is also commonly identified in the absence of pubic marrow changes. This suggests adductor dysfunction most likely precedes pubic marrrow changes.
FIG 2 • Secondary cleft sign seen on T2-weighted coronal MRI, suggesting a partial avulsion of the adductor longus on the right.
In addition to signal changes within the adductor origin, muscle tendon junction, or pubis, a secondary cleft sign may be present.
Brennan et al3 defined the abnormal secondary cleft as an extension of the normal hyperintense signal seen within the central symphyseal cleft to a location lateral to the midline or inferior to the joint.
The secondary cleft is best visualized on a coronal STIR image (FIG 2). This secondary cleft, like pubic marrow changes, is thought to be a consequence of prolonged traction on the pubic rami and common aponeurosis anterior to the symphysis.
Chronic injury leads to a communication between the central and secondary clefts owing to a microtear or partial avulsion of the adductor longus from the pubis.3,4
DIFFERENTIAL DIAGNOSIS
Athletic pubalgia (sports hernia)
Inguinal hernia
Acetabular labral tear
Hip arthritis
Femoral neck stress fracture
Hip synovitis
Referred testicular pain
Gynecologic pathology
Coxa saltans
Iliopsoas strain
Intra-abdominal disorders
NONOPERATIVE MANAGEMENT
Adductor-related acute strains and overuse injuries are all initially managed with rest, ice, compression, and elevation (the RICE method) and a brief period of nonsteroidal antiinflammatory drugs (NSAIDs). Differentiation between a strain and an enthesopathy is critical, because musculotendinous strains are managed much more aggressively with early, active therapy.
Early on, active and passive range of motion without pain is initiated.
Once full, painless range of motion has been achieved, a progressive strengthening regimen is started. Increased emphasis is placed on core stabilzation and strengthening of the pelvic musculature.
Resistance training consists predominantly of eccentric exercise for the hip and pelvic musculature.
Holmich et al5 demonstrated that an active strengthening and coordination program for the pelvic musculature was significantly better than conventional physical therapy in treating chronic athletic-related groin pain.
Nonoperative therapy is completed with sport-specific training and eventual return to play.
Early return to play is not advised because of the high risk of recurrent injury. Tyler et al14,15 showed the best predictor of a future groin strain was an adductor-to-abductor muscle strength ratio of less than 80%.
Acute adductor avulsions are best managed with nonoperative means, despite reports of successful repair.8,11
Schlegel et al11 reported on 19 acute avulsions in NFL players, where those managed nonoperatively had good outcomes and a markedly shorter recovery time.
Verall16 reported on a specific nonoperative regimen for sports-related groin pain with MRI-documented pubic stress changes. Twenty-seven athletes were rested for 12 weeks, followed by an active therapy regimen. When evaluated by return to sport criteria, outcomes were excellent.
However, results were satisfcatory only if the criterion of ongoing symptoms was used, because nearly a third of individuals remained symptomatic during their second season post–nonoperative treatment.
Additionally, 26% of these athletes were participating at a lower level of competition.
Holmich et al5 reported on 23 of 29 athletes with chronic adductor-related groin pain returning to symptom-free play at 19 weeks as a result of an active therapy program. Long-term follow-up was not obtained, and these injuries were not stratified regarding strain versus enthesopathy versus avulsion.
SURGICAL MANAGEMENT
Chronic adductor-related groin pain that has failed nonoperative measures, including an active therapy program focused on strengthening of the pelvic musculature and core stabilization, can be successfully treated with tenotomy of the adductor longus.1 Although adductor tenotomy previously was reserved for patients with spasticity, it clearly has a role in the management of chronic and disabling groin pain in the athlete. Tenotomy is performed as an isolated procedure or in conjunction with a sports hernia repair.
Individuals suspected of having a concomitant sports hernia are referred to a general surgeon for definitive management.
Preoperative Planning
Surgical planning consists primarily of an extensive history and physical examination to confirm that the pain is isolated to the adductor and that all appropriate nonoperative measures have been exhausted.
Additionally, a confirmatory MRI revealing enthesopathy or chronic strain with associated pubic marrow changes or cleft sign is warranted.
Positioning
The patient is placed in the supine position with the operative extremity in an abducted and externally rotated position (FIG 3). The adductor origin is easily palpated in this position. Only the ipsilateral groin is prepped and draped.
Approach
The adductor longus is superficial and proximal to the adductor brevis and adductor magnus origins.
A 3-cm incision is marked about 1 cm inferior and parallel to the inguinal crease. This incision is centered over the palpable tendinous mass.
FIG 3 • The operative thigh is flexed, abducted, and externally rotated to provide excellent exposure and easy palpation of the adductor origin.
TECHNIQUES
OPEN ADDUCTOR LONGUS TENOTOMY
The skin is incised in line with the previous mark down to the underlying fascia (TECH FIG 1A). The fascia is incised in a similar fashion, parallel to the skin incision, revealing the underlying adductor longus proximal tendon.
The tendon is readily identified, and care is taken to identify the medial and lateral borders, noting that the lateral aspect often is composed of muscle fibers without a true tendinous component.
Once the borders are defined, the tendon is elevated from the underlying adductor brevis and divided with cautery about 1 cm from its pubic origin while protecting the underlying adductor brevis (TECH FIG 1B). Note that the undersurface of the adductor longus is entirely muscular.
Remaining proximal also protects the anterior division of the obturator nerve as it runs its course along the anterior aspect of the adductor brevis.
Although some have reported suturing the distal stump of the cut tendon to the overlying fascia, this is not necessary; no distal retraction or deformity has been encountered in our experience.
The fascia is repaired with an absorbable suture, and the overlying skin is approximated.
TECH FIG 1 • A. The skin incision is 3 to 4 cm long, just inferior and parallel to the inguinal crease, centered over the adductor origin. B. The distal free edge of the transected adductor longus tendon.
POSTOPERATIVE CARE
Immediate ambulation is permitted without assistive devices. Stretching is avoided until the incision has healed.
Once the incision has healed, a progresive strengthening and stretching routine is initiated, with an emphasis on core stabilization.
OUTCOMES
Akermark1 performed isolated adductor tenotomy in 16 athletes with chronic adductor-related groin pain. All patients reported significant improvement. Fifteen of 16 returned to sporting activities within 6 to 8 weeks, and 12 of 16 returned to competitive sports by 14 weeks. Only 10 athletes returned to full athletic competition; five returned to a reduced level of competition.
As one might expect, patients had decreasesd isokinetic testing relative to the nonoperative side. However, these patients were reported to maintain functional sports activity despite the measured deficit.1
A definitive recommendation to proceed with adductor tenotomy is difficult, particularly in the high-performance athlete. Therefore, adductor tenotomy is reserved as a last-ditch effort to return the chronicaly disabled athlete to competitive sports with the possibility of participation at a reduced level of performance.
Additional study investigating nonoperative and surgical intervention of adductor-related groin pain clearly is warranted.
COMPLICATIONS
There are no reported complications for adductor tenotomy, because few series have been reported.
We suspect that persistent groin pain attributed to an incorrect diagnosis or an untreated concomitant sports hernia is the most prevalent complication from adductor-related surgery.
REFERENCES
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2. Albers S, Spritzer C, Garrett WE, et al. MR findings in athletes with pubalgia. Skeletal Radiol 2001;30:270–277.
3. Brennan D, O'Connel M, Ryan M, et al. Secondary cleft sign as a marker of injury in athletes with groin pain: MR image, appearance and interpretation. Radiology 2005;235:162–167.
4. Cunningham P, Brennan D, O'Connel M, et al. Patterns of bone and soft-tissue injury at the symphysis pubis in soccer players: observations at MRI. AJR Am J Roentgenol 2007;188:W291–W296.
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