COMPARTMENT SYNDROME (see Figure 3) ❏ in anatomical "compartments" where muscle and tissue bounded by fascia and bone (fibro-osseous compartment) with little room for expansion (i.e. forearm, calf) ❏ increased interstitial pressure in compartment exceeds capillary perfusion pressure which leads to muscle necrosis and eventually nerve necrosis ❏ intracompartmental pressures over 30 mm Hg usually require intervention Etiology ❏ fracture, dislocation ❏ soft tissue damage and muscle swelling ❏ crush injury ❏ arterial compromise ❏ muscle anoxia ❏ venous obstruction ❏ increased venous pressure ❏ constrictive dressing, cast, splint Diagnosis ❏ classically the tibial compartments ❏ also in forearm flexor compartment • may lead to Volkmann’s ischemic contracture ❏ clinical signs and symptoms • early • pain • greater than expected for injury • not relieved by analgesics • increase with passive stretch of compartment muscles • pallor • palpable tense, swollen copmparment • late • paralysis (inability to move limb - late) • pulses are usually still present • paresthesias • NOT pulslessness • most important feature found on physical exam is PAIN out of proportion to injury (the other signs are ‘late signs’) ❏ compartment pressure monitoring • in unresponsive or unreliable patients • normal tissue pressure is about 0 mm Hg • pressure increases markedly in compartment syndromes. • when intra-compartmental pressure rises to within 10 to 30 mm Hg of patient's diastolic blood pressure inadequate perfusion and/or ischemia results • fasciotomy usually is indicated when the tissue pressure rises to 40-45 mm Hg in a patient who has any signs or symptoms of a compartment syndrome-even if distal pulses still present Table 4. Signs of Compartment Syndrome in Anterior Leg and Forearm Anterior leg Volar forearm Fracture Type Tibial fracture Supracondylar (humerus) Weakness Toe, foot extension Finger, wrist flexion Pain Toe, foot flexion Finger, wrist extension Sensory 1st dorsal web space Volar aspect of fingers Treatment ❏ remove constrictive dressings ❏ bivalve casts down to skin and spread open ❏ place limb at level of heart ❏ emergency fasciotomy to release compartments if difference between diastolic blood pressure and compartment pressure is less than 30 mmHg (treat within 4-6 hours of onset symptoms) Figure 3. Pathogenesis of Compartment Syndrome
MCCQE 2002 Review Notes Orthopedics – OR7 FRACTURES - GENERAL PRINCIPLES . . . CONT. AVASCULAR NECROSIS (AVN) Causes ❏ steroid use (inflammatory arthritis, inflammatory bowel disease (IBD), allergies, renal disease, asthma); NOT dose related - idiosyncratic ❏ alcohol ❏ post-traumatic fracture/dislocation ❏ septic arthritis ❏ sickle cell disease ❏ Gaucher’s disease ❏ Caisson’s disease - deep sea diving/the bends ❏ idiopathic Table 5. AVN Classification Stage Clinical Features X-ray Features 1 Preclinical phase of ischemia No plain x-ray abnormality; and necrosis; no pain
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- Spring '15
- Orthopedic surgery, Bone fracture, open fractures