Magnetic resonance imaging in exertional compartment syndrome of the forearm: Case-based pictorial review and approach to management

Abstract

Exercise-related limb pain poses a management dilemma to the clinician. The term ‘chronic exertional compartment syndrome’ (CECS) (previously known as ‘anterior tibial syndrome’) refers to a condition characterised by exercise-induced pain in one or more muscle groups and is more commonly seen in the lower limbs. Much less has been reported about the upper limbs where the muscular compartments are variably noted to be involved. A high index of clinical suspicion should therefore be maintained to avoid missing the diagnosis. Although commonly noted in athletes, CECS can occur in any age group with any level of exercise activity. In addition, there is no age predilection and the syndrome may be bilateral. The exact prevalence is not known as many athletes modify their training methods, thus delaying or avoiding medical assistance and imaging. The pathophysiology of compartment syndrome is complex. In this review of the syndrome, we describe the cycle of intracellular events leading to CECS and the eventual destruction of muscle. There is considerable overlap with the many possible causes of limb pain. Even the most experienced clinicians experience some difficulty in making this diagnosis of CECS, but with increasing awareness of this entity and availability of good-quality magnetic resonance imaging to confirm the suspicion, upper limb CECS is being more commonly diagnosed and patients more timeously managed.

MRI findings in chronic exertional compartment syndrome of the forearm: Using signal intensity ratio as a diagnostic tool

“…2,4,7,8,10,11,12,14,15 The pathophysiology of the condition remains incompletely understood but is based on the premise of raised intra-compartmental pressures within a relatively rigid fascial compartment, causing reduced tissue perfusion and subsequent ischaemia. 2,8,15,16,17,18,19,20 During exercise, it is normal for intra-compartmental pressures to rise; however, this increased pressure does not usually cause symptoms or altered tissue oxygenation as in patients with CECS. 2,9,19 Patients with CECS have relatively greater increases in pressure and these pressures also take longer to return to normal after cessation of exercise.…”

“…1,23,25 Furthermore, the invasive nature of testing, the associated risks and the lack of an accepted testing technique make intra-compartmental pressure manometry a far from ideal diagnostic tool. 7,10,12,17,18,20,23,26 MRI in chronic compartment syndrome is based on the premise that ischaemic muscle will become oedematous and thus exhibit a more intense T2-weighted (T2W) signal compared with normal muscle. 15,17,26 Additionally, MRI can accurately exclude other conditions that may mimic CECS, for example, tendonitis, muscle tears and nerve impingements.…”

“…7,10,12,17,18,20,23,26 MRI in chronic compartment syndrome is based on the premise that ischaemic muscle will become oedematous and thus exhibit a more intense T2-weighted (T2W) signal compared with normal muscle. 15,17,26 Additionally, MRI can accurately exclude other conditions that may mimic CECS, for example, tendonitis, muscle tears and nerve impingements. MRI scanning has been utilised for the past 30 years in the diagnosis of CECS, with numerous studies and case reports published at testing to its usefulness.…”

“…MRI scanning has been utilised for the past 30 years in the diagnosis of CECS, with numerous studies and case reports published at testing to its usefulness. 4,9,13,16,17,19,26,27,28,29 Despite the relatively strong evidence for the use of a prepost exercise MRI protocol in CECS, no standardised methods regarding exact exercise protocols and imaging acquisition have been published. 6,15,17,26,28,30 Furthermore, in the absence of T2W mapping software, signal intensity (SI) is graded subjectively, presenting the possibility for greater inter-observer variations.…”

“…4,9,13,16,17,19,26,27,28,29 Despite the relatively strong evidence for the use of a prepost exercise MRI protocol in CECS, no standardised methods regarding exact exercise protocols and imaging acquisition have been published. 6,15,17,26,28,30 Furthermore, in the absence of T2W mapping software, signal intensity (SI) is graded subjectively, presenting the possibility for greater inter-observer variations. 6 The ever-increasing competitiveness and demands faced by top-level and professional athletes require that timeous and accurate diagnosis of any sporting-related symptoms is paramount to the longevity and success of an athlete.…”