Chronic Exertional Compartment Syndrome of the Foot. A Case Report

Abstract

The author describes a case of chronic exertional compartment syndrome of the foot affecting a 19-year-old male triathlete. Relevant anatomy, subjective symptoms, and clinical examination are discussed. Diagnostic confirmation, as achieved with compartment-pressure testing, is also presented, as is surgical treatment through decompressive fasciotomy of the affected compartment.

This article describes a case of chronic exertional compartment syndrome, at the medial compartment of the foot, in a 19-year-old male triathlete. The condition is becoming recognized as one that may manifest in the foot. Symptoms are analogous to those produced by chronic exertional compartment syndrome at other sites of the body. Diagnosis may be definitively established through compartment-pressure testing. Decompressive fasciotomy of the affected compartment appears to be the treatment of choice. Of all fascial compartments within the foot, the medial compartment appears most susceptible to development of chronic exertional compartment syndrome.

Case Report

A 19-year-old male presented with a 5-month history of recurrent pain, localized to the arch and the medial aspect of his right foot. He described a history of persistent foot blistering, as well as a right tibial stress fracture 1 year previously. The patient was an active triathlete, completing 2 km of swimming, 90 km of bicycling, and 45 km of running per week.

Walking and other daily activities resulted in no discomfort. Symptoms were absent during bicycling and swimming, yet became apparent during running. The patient reported sensations of “cramp-like pain” and tightness at the arch of his right foot that was noticeable after approximately the first 3 km of running. Pain was sometimes preceded or followed by tingling or numbness, and was independent of the running shoes in which he trained.

Symptom intensity increased in proportion to the duration of activity. When most symptomatic, the patient felt a sensation akin to “the arch of the foot bursting.” He noted that discomfort diminished after several minutes of rest, yet returned quickly when he tried to resume activity.

On physical examination, the medial aspect of the right midfoot appeared mildly indurated. Dorsalis pedis and posterior tibial pulses were strong and easily detected. Palpation of the abductor hallucis muscle belly, medial to the plantar fascia, proved mildly painful. No abnormality was detected during bilateral lower-limb strength testing. Dynamic assessment revealed prolonged, excessive talocalcaneal joint pronation bilaterally, a moderately abducted foot position, and an everted calcaneal position evident bilaterally during the propulsive phase of running gait.

Symptoms were reproduced after the patient jogged several kilometers on a treadmill. Examination following activity revealed tense swelling at the medial aspect of the midfoot; great pain was elicited on direct palpation of this site. Resisted plantarflexion and passive dorsiflexion of the right hallux also proved painful. A provisional diagnosis of chronic exertional compartment syndrome was reached. Compartment-pressure testing was subsequently undertaken, using a Stryker Intracompartmental Pressure Monitor System ® (Stryker Corp, Kalamazoo, MI.), at the medial compartments of both feet, and also at the superficial compartment of the symptomatic foot. Test results confirmed chronic exertional compartment syndrome of the medial compartment of the right foot (Table 1).

Decompressive fasciotomy of the medial compartment of the right foot was later performed. An incision was made at the medial aspect of the right midfoot, plantar to the first metatarsal–medial cuneiform articulation, allowing visualization of the abductor hallucis muscle belly and the lateral wall of the medial compartment. The muscle was retracted, and the lateral wall of the compartment (a fascial septum emanating from the plantar aponeurosis) was incised longitudinally and transversely. Care was taken to avoid the lateral plantar nerve and accompanying vessels, located immediately lateral to the incised fascia. The surgical incision was closed in layers, and the patient was confined to bed for several days.

Five days after surgery, the patient was walking without pain. Four months postoperatively, the patient was slowly returning to full training, and could complete a 3-km run over flat terrain without experiencing discomfort. Following surgery, foot orthoses were prescribed in order to correct poor foot function noted on initial examination. Repeat compartment-pressure measurements 5 months after surgery demonstrated a reduced resting pressure at the medial compartment of the right foot comparable to that in the asymptomatic foot.

Discussion

Compartment syndrome of the foot has been the focus of many recent articles.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15] However, relatively few authors [4,9,10,14] have addressed the chronic exertional form of the injury manifesting in the foot. Previous case reports have described the syndrome in an 18-year-old male ballet dancer,[4] a 16-year-old female who participated in high-impact aerobics,[9] a 30-year-old male long-distance runner,[10] and a 15-year-old female soccer player and cheerleader.[14]

Chronic exertional compartment syndrome may be described as a transient, symptomatic pressure increase within a myofascial compartment, precipitated by exercise and subsiding with cessation of athletic activity. Manoli and Weber[7] have identified nine distinct fascial compartments within the foot. The medial, superficial, and lateral compartments span the length of the foot, while the calcaneal compartment is limited to the rearfoot. The adductor compartment and four interossei compartments are localized to the forefoot.[7]

Of all fascial compartments within the foot, the medial compartment appears most susceptible to chronic exertional compartment syndrome. It is the site of injury in this report as well as in all previous case studies detailing chronic exertional compartment syndrome manifesting in the foot.[4,9,10,14] Lokiec et al[4] described concurrent involvement of the medial and superficial compartments.

The medial compartment contains the abductor hallucis and flexor hallucis brevis muscles; tendons of flexor hallucis longus, peroneus longus, and tibialis posterior; and the medial plantar nerve. The compartment’s medial wall is primarily connective tissue medial to the abductor hallucis, as well as fibers of the flexor retinaculum. It is defined laterally by a fascial slip stemming from the plantar aponeurosis; superiorly by the plantar surfaces of the first metatarsal, medial cuneiform, and navicular; and inferiorly by the plantar aponeurosis.[7,11,16] The medial compartment does not communicate with any other compartment of the foot or ankle.

Regardless of the location or etiology of chronic exertional compartment syndrome, increased tissue pressure is a prerequisite for development of the condition.[17,18] Pressure increases may result from limited compartment volume, poor transient expansion of a compartment, muscular hypertrophy, elevated tissue perfusion during activity, or extrinsic factors such as taping, bracing, casts, prostheses, footwear, or orthoses.[9,17,19,20]

Table 1. Results of Compartment-Pressure Testing Following Reproduction of Patient Symptoms via Treadmill Running.

Table 1. Results of Compartment-Pressure Testing Following Reproduction of Patient Symptoms via Treadmill Running.

Excessive talocalcaneal and talonavicular joint pronation may provide compression of the medial compartment of the foot sufficient to precipitate pressure increases. Abductor hallucis muscle hypertrophy may also be considered as an etiologic factor.

Initial physical examination of the athlete with chronic exertional compartment syndrome of the foot may be unremarkable.[9] Palpation of the affected compartment with the athlete at rest may allow detection of localized muscular hypertrophy.[4,14] Following activity aimed at reproducing symptoms, palpation of the affected compartment will induce intense pain, as will passive stretch of muscles within the affected compartment(s).[9] Magnetic resonance imaging assists in the identification of muscular hypertrophy, which may precipitate chronic exertional compartment syndrome of the foot.[4,14]

As at other anatomic sites, definitive diagnosis of chronic exertional compartment syndrome may be achieved through compartment-pressure testing. In this report, a Stryker Intracompartmental Pressure Monitor System was used, an instrument that has been used in previous studies of compartment pressures and chronic exertional compartment syndrome.[9,10,13,14,21,22]

Standardized patient positioning during testing of compartment pressures at the foot is important given the potential for variation with differing foot and lower-limb placement in relation to the heart.[22] Standardized positioning with the patient supine and the feet and the heart on the same horizontal plane has been described previously[22] and was used during all measurements in this case.

The criteria for confirmation of chronic exertional compartment syndrome diagnosis following pressure testing are not strictly defined. The detection of an elevated resting compartment pressure is thought to be indicative of injury, as are abnormally high pressures during and immediately following activity and delayed pressure normalization with termination of activity.[14,18,19,23,24,25,26,27,28] Resting compartment pressure above 15 mm Hg 15 minutes after completion of activity that reproduces symptoms has been adopted as a diagnostic parameter of chronic exertional compartment syndrome in the anterior compartment of the leg.[27]

Differential diagnoses of chronic exertional compartment syndrome of the foot are many, including tibialis posterior tendon injury, tarsal or metatarsal stress fracture, peripheral arterial entrapment or obstruction, medial calcaneal nerve or medial plantar nerve entrapment, tarsal tunnel syndrome, accessory muscle, neurologic disease, and tumor. Nerve-conduction studies may identify nerve entrapment, which can mimic chronic exertional compartment syndrome.[29]

This report and previous reports [4,9,10,14] describe excellent results obtained with decompressive fasciotomy of the medial compartment of the foot. Conservative treatment of chronic exertional compartment syndrome of the foot has not been described previously, and was not considered in managing the patient presented here. All documented cases of chronic exertional compartment syndrome of the foot have identified very high resting or immediate postactivity compartment pressures, indicating severe injury. Future reports describing milder cases may elect to assess the efficacy of conservative measures such as rest, application of ice, massage, footwear changes, training modifications, and foot orthoses.

Conclusion

Chronic exertional compartment syndrome of the foot is a recently recognized condition, presenting with characteristic symptoms analogous to those reported with onset at the lower leg and other sites. Diagnosis may be definitively established through compartment-pressure testing. Currently, decompressive fasciotomy is the treatment of choice. Future investigations of chronic exertional compartment syndrome of the foot may identify factors responsible for its apparent predilection for the medial compartment.