Does Compartment Syndrome of the Foot Really Exist? How Should I Treat It?
Michael S.
Pinzur,
MD
The clinical entity of compartment syndrome in the 2 compartments of the forearm and 4 compartments of the leg is well accepted. Delay in diagnosis leads to paralysis, deformity, and appreciable permanent disability. The first question that must be addressed is whether the anatomy of the foot would support a similar pathologic process. Manoli and Weber have described 4 compartments in the foot that encase the entire muscle bellies of the intrinsic muscles of the foot with facial connective tissue.1 The question is whether a crush injury with or without bony fracture can produce sufficient bleeding and/or swelling to create an outflow obstruction that is sufficient to impair arterial inflow, leading to muscle death and late joint contracture. The simple answer is yes. The complex answer is how do we diagnose this specific clinical entity, and is the morbidity of treatment worse than the natural history?
Compartment syndrome can develop in the foot following crush injury or closed fracture. Following some critical threshold of bleeding and/or swelling into the fixed space compartments, arterial pulse pressure is insufficient to overcome the osmotic tissue pressure gradient, leading to cell death. The complicating factor is related to the magnitude of the force of the crush injury. The amount of swelling or bleeding has to be sufficient to impair arterial inflow, while not being of sufficient magnitude to produce an open injury, which decompresses the pressure within the affected compartments. When the injury is open, we then attribute the late disability primarily to the crushing injury to the involved muscles.
To make diagnosis even more complex, we do not fully understand how frequently the crush injury and resultant swelling lead to neurogenic pain (ie, complex regional pain syndrome [CRPS] or reflex sympathetic dystrophy [RSD]). Both compartment syndrome and CRPS are frequently initiated by a crush injury with resultant swelling. How often is the pain associated with CRPS actually secondary to an overlooked compartment syndrome of the foot? How many patients with residual compartment syndrome are wrongly diagnosed with CRPS?
What is the natural history of untreated compartment syndrome in the foot? What is the late outcome of many patients with CRPS? The answer is that the clinical sequela of both conditions can be strikingly similar. To avoid operating on every patient with RSD, we need to consider the natural history of untreated compartment syndrome of the foot.
The acute pain associated with missed, or untreated, compartment syndrome of the foot eventually resolves to some degree. Patients typically develop joint stiffness and clawing of the toes. This sounds remarkably similar to some patients with CRPS. How can we treat these patients? Aggressive physical therapy, nerve blocks, and accommodative footwear often alleviate many of the symptoms. When the deformities of the toes are sufficiently symptomatic, we can offer reconstructive claw toe surgery, fusion of the hallux metatarsophalangeal joint, and/or excision of the scarred nonfunctional muscle.2
Is there a worst case scenario associated with compartment syndrome of the foot? The patient in Figure 46-1 developed significant soft tissue swelling of the heel associated with a closed calcaneus fracture that was initially treated with a well-padded splint and compression dressing. The fracture was treated with fine wire external fixation. The blister identified in Figure 46-1 progressed to a full-thickness skin loss that healed by secondary intention. Was this clinical entity a compartment syndrome associated with the closed calcaneus fracture, or was this a simple fracture blister?
Figure 46-1. (A) This patient returned to clinic 10 days after sustaining a closed calcaneus fracture that was treated in a well-padded splint. (B) Two weeks later, he developed a full thickness skin loss. Was this a compartment syndrome of the foot or a simple fracture blister?
What clinical outcomes can we expect with prompt correct diagnosis of compartment syndrome of the foot and urgent surgical decompression? In the best case scenario, the wounds heal with minimal scarring, intrinsic muscle function is maintained, and the patient exhibits little late difficulty with footwear. Unfortunately, this optimal favorable outcome is the exception rather than the rule. The resultant scars and necessary skin grafting can be worse than the untreated patient.
Does compartment syndrome of the foot exist? The evidence and my personal experience would suggest that the answer is yes. Can one distinguish compartment syndrome of the foot from acute neurogenic crush injury that will eventually lead to CRPS or RSD? That is a very difficult question to answer, due to the similar common endpoints of both clinical entities. For these reasons, I choose to accept the natural history method of treatment. We use compression dressings and cold therapy. If the treatment is noninterventional observation, the patient perceives his or her less-than-favorable outcome as a consequence of the injury. If one performs aggressive surgery and achieves a similar unfavorable outcome, the patient associates this poor outcome with the surgery and the surgeon.
References
1. Manoli A II, Weber TG. An anatomic study with special reference to release of the calcaneal compartment. Foot Ankle. 1990;10:267-275.
2. Perry MD, Manoli A II. Reconstruction of the foot after leg or foot compartment syndrome. Foot Ank Clin. 2006;11:191-201.