CAUSES OF COMPARTMENT SYNDROME
In compartment syndrome, increased tissue pressure within a confined anatomic space (closed space) impairs the arterial flow required to oxygenate muscles and nerves. If relief of this critical ischemia is delayed beyond 8 hours, nerve and muscle necrosis follows; then both structure and function are compromised, often irreparably.5-7
This sequence begins with any injury that causes increased pressure in a closed compartment either through extrinsic or intrinsic pressure. Trauma is the most frequent cause via crush injury or any source of bleeding or transudation of fluid. Tight dressings or casts can compress arterial flow even without any tissue leakage. Insidious onset can follow thermal or chemical burns if circumferential eschar production chokes venous return and leads to venous congestion so severe as to prevent arterial perfusion.
Many other paths can lead to the profound fluid accumulation that eventuates in compartment syndrome. Among these are snakebite; reperfusion leakage after 4 to 6 hours of critical limb ischemia; edema in anasarca; and spontaneous hematomas due to coagulopathy or to therapeutic anticoagulation or to thrombolysis.
Sequelae of compartment syndrome include myonecrosis followed by muscle fibrosis that ultimately becomes contracture. The contractures constitute the structural announcement of the profound functional debility, and a further source of difficulty in themselves via pain and via further impeding whatever residual contractile function remained to act upon the joint in question.
WHEN TO CONSIDER COMPARTMENT SYNDROME
Compartment syndrome rises in the differential diagnosis whenever pain is disproportionately great in an acute injury. Of course, emotional amplification and secondary gain can exaggerate reported pain; often clinical exclusion of such elements is straightforward.
Clinical findings in compartment syndrome often include a swollen, tense, painful region, sensory deficits, and eventual motor dysfunction. The most reliable finding of compartment syndrome is pain on passive stretch of the involved muscle. Such pain classically is persistent, progressive, and not relieved by immobilization. It is by no means pathognomonic; a torn muscle, or a myohematoma among things, might mimic the features even without complication, but might also lead to a true compartment syndrome.
A flawed mnemonic persists: 5 “P”s of compartment syndrome:
• Pain: an early and sensitive sign albeit highly nonspecific.
• Paralysis (of the muscle group involved) is usual.
The other elements are much less sensitive:
• Pulselessness: late and undependable.
• Pallor: one ought not wait for this.
• Paresthesia: inconsistent.
Thus an incomplete pentad ought never deter a putative diagnosis and the necessary surgical consultation. The surgeon may perform direct manometric tissue pressure measurements, or exploration including for decompression via fasciotomy.
DID SHE EVER HAVE COMPARTMENT SYNDROME?
None of our patient’s findings indicate compartment syndrome at present. Did she have this in the past, leading to the Volkmann deformity?
Although her dysphonia is profound, her cognition imperfect, and her affect clouds some responses, this woman tried her best to tell us all about the development of her hand and wrist changes. She did not recall any cast or fracture and did not recognize the term “compartment syndrome.”
It is possible that she had injuries that went unattended for months or years and first came to attention after the completion of florid contracture, but we must acknowledge a level of uncertainty about the sequence of injury and mal-repair.
Presently, when she has requested purely palliative care, we cannot justify imaging merely to satisfy our curiosity about the state of the muscles, tendons, and nerves of the forearm. We know that Volkmann contracture can occur without ischemia, from cysticercosis of muscles among many other rare causes,8 so we cannot even make a good guess about which prospective cause applied. We’d be grateful for any thoughts from readers that would move us forward.
CAN WE GENERALIZE?
We started with a sign that was utterly unfamiliar and then found a “best match” that had the half-familiarity of having been mentioned in medical school but never seen (or at least never recognized) by either author. Our look at the literature on Volkmann contracture, starting with the initial clinical report,1 underscored profoundly varied and confusing proposed mechanisms of pathogenesis. Even when the role of compartment syndrome emerged, controversy about this syndrome abounded: an infinity of speculations, some supported by experiment, but many mutually contradictory until satisfactory unifying hypotheses and mechanisms became established.5 Perhaps in that context, our confusion about the sign, and our still unanswered questions about this case, can be viewed with tolerance and forgiveness.
Along the way we read extraordinary reports of Volkmann contracture in hemophilic myohematomas, in a paper from 73 years ago9 that proved remarkably insightful and even prescient about mechanism, and another that dissected multiple pathophysiological strands in Volkmann contracture following carbon monoxide poisoning, supported by multiple muscle biopsies and much astute rational inference, dating back to 1967.10
HOW MUCH MORE WAS GOING ON
We also saw, again, how readily an astounding abnormality can remain unlabeled when overall status and functional problems command all attention of the medical team. In this patient, though one would think the hands and wrists would never stop hurting, she insisted that her chronic opiate requirement related to back pain, not to the upper limbs. Finally, we noticed that the clubfoot deformity11 (Figure 4) stood even further down on the list of unnamed problems than the hands, and appeared to have developed entirely independently of them, perhaps akin to the pes equinus sometimes seen years after loss of ambulation.12
These experiences validated the old dicta, “Avoid a too-tight tourniquet in controlling bleeding in the field” and “You can indeed bandage too tightly.” Any suspected compartment syndrome calls for early consultation and very likely a procedure, though fasciotomy may be contraindicated in some acute muscle crush-injury–related compartment syndromes.5 We’d like to play our small part in reducing the chance of ever seeing another Volkmann contracture.
Schneiderman H, Kumar S. Volkmann ischemic contracture in a woman with end-stage Parkinson disease and a host of unanswered questions. CONSULTANT. 2009;49:447-451.