Brian P. Jacob, David C. Chen, Bruce Ramshaw, Shirin Towfigh (eds.) - The SAGES Manual of Groin Pain-Springer International Publishing (2016)

7. Groin Pain Etiology: Athletic Pubalgia Evaluation…
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Induced by exercise, the pain has a characteristic clinical pattern of
medial thigh pain commencing in the region of the adductor muscle
origin and radiating distally along the medial thigh, with strenuous
exercise. An anatomic study on cadaver limbs by Harvey and Bell
reinforced the concept that obturator neuropathy is caused by an entrapment
syndrome due to the angle that the nerve pierces the adductor
muscles and travels between the adductor fascial compartments [ 20 ].
In athletes, congenital anatomic nerve variants combined with physical
training that augments adductor muscle development may be the
main mechanism for obturator nerve entrapment syndrome in athletic
pubalgia.
In addition to the sensory abnormalities, motor deficits can be found
in advanced cases of obturator nerve entrapment. Physical exam may
reveal asymmetry between affected and non-affected sides, with weakness
and atrophy of adductor muscles on the affected. MRI will rarely
show nerve- related injury, but is helpful to rule out adductor or gracilis
tendonitis involvement. In cases where the MRI is normal, but clinical
suspicion is high, the best test to confirm obturator neuropathy is needle
electromyography (EMG). Kimura et al. noted that fibrillation potentials
or high-amplitude, long-duration complex motor unit potentials were
consistent with chronic denervation of the hip adductor muscle group,
but not in other lower extremity muscles [ 21 ].
Treatment of Nerve Entrapment Syndromes
Nerve pain is generally as hard to treat as it can be to diagnose. The
longer the pain symptoms have persisted, the more difficult it is to
achieve adequate cessation of pain. In fact, treatment strategies can be
divided into acute and chronic/recurring pain categories. For all three
neuralgia syndromes, acute pain is best treated with activity cessation
and NSAIDs for 3–6 weeks, followed by a strength and flexibility rehabilitation
program that leads to competitive activity resumption. Regional
nerve blocks that are diagnostic of nerve entrapment can be modified
with long-acting local anesthetics (bupivacaine) and a corticosteroid
(prednisolone tebutate) for sustained pain relief. For chronic and recurring
pain that prevents full return to training and competition, nerve
surgery will be required. For the ilioinguinal and genitofemoral nerves,
neurectomy, often together, achieves good results. Since these nerves are
mostly sensory in function, resection at the level of the transversus