Eduovisual
Musculoskeletal
Compartment syndrome: recognition and management
— Tissue pressure rises → venous outflow obstructed → capillary collapse → ischemia → cellular edema → further pressure rise (vicious cycle).
— Irreversible muscle injury begins at ~4–6 hours of sustained ischemia; nerve injury can begin within 30 minutes of ischemia but is reversible up to ~4 hours.
— Tibial shaft fracture (most common cause; ~2–9% incidence) and distal radius fracture in young males.
— High-energy blunt trauma, crush injury, prolonged limb compression (intoxication, OR positioning, "found down").
— Tight casts or circumferential burns/eschar.
— Reperfusion after arterial repair or prolonged tourniquet use.
— Bleeding diatheses (anticoagulants, hemophilia) with even minor trauma.
— IV infiltration/extravasation, especially in neonates and obtunded patients.
— Vigorous exercise (exertional/chronic compartment syndrome — separate entity).
Board pearl: A young male with a tibial shaft fracture complaining of pain out of proportion to exam and worsening despite immobilization and opioids is ACS until proven otherwise — do not wait for the classic "6 P's."
Step 3 management: Suspicion alone in a high-risk patient mandates immediate removal of all circumferential dressings/casts, limb positioning at heart level (not elevated — elevation worsens perfusion gradient), and urgent orthopedic surgery consultation while compartment pressures are measured.
— Pain out of proportion to the injury or exam is the earliest and most sensitive finding.
— Pain is deep, burning, poorly localized, and escalating despite immobilization and adequate analgesia.
— Pain with passive stretch of muscles within the affected compartment is highly suggestive (e.g., passive toe flexion stresses the anterior leg compartment).
— Opioid requirements that climb rapidly should trigger reassessment, not dose escalation.
— Mechanism, time of injury, time of last "normal" exam.
— Anticoagulant/antiplatelet use, bleeding disorders.
— Cast or splint placement timing; tightness sensations.
— Substance use, found-down history, prolonged immobilization.
— Recent vascular procedure, IV infiltration, snake/insect envenomation.
— Burn history with circumferential eschar.
Key distinction: ACS vs arterial injury — ACS preserves distal pulses early; absent pulses suggest concurrent arterial injury or very late ACS. Never use "pulse present" to rule out compartment syndrome.
Board pearl: Escalating analgesic needs in a casted extremity = bivalve the cast immediately and reassess; this is both diagnostic and therapeutic and is the correct first step before pressure measurement.
— Tense, shiny, swollen compartment; skin may be tight without overt erythema.
— Look for fracture deformity, ecchymosis, blistering, eschar, or extravasation site.
— Compare with contralateral limb side-by-side.
— Woody, firm, non-compressible compartment is highly suggestive.
— Tenderness diffuse over the compartment, not just the fracture line.
— Anterior leg: pain with passive plantarflexion of toes/ankle.
— Lateral leg: pain with passive inversion.
— Deep posterior leg: pain with passive toe extension and ankle dorsiflexion.
— Superficial posterior leg: pain with passive ankle dorsiflexion.
— Volar forearm: pain with passive finger/wrist extension.
— Dorsal forearm: pain with passive finger/wrist flexion.
— First dorsal webspace sensation (deep peroneal n.) — earliest sensory deficit in anterior leg ACS.
— Motor weakness is a late finding; do not wait for it.
— Check dorsalis pedis, posterior tibial, radial, ulnar pulses; obtain ABI if any asymmetry or mechanism suggests vascular injury.
— Capillary refill and pulses are typically normal in early-to-mid ACS — falsely reassuring.
— Doppler signals may persist even with severe compartment ischemia.
CCS pearl: In the CCS interface, order "serial neurovascular checks q1h," "remove cast/splint," "elevate to heart level," and "orthopedic surgery consult — urgent" simultaneously when ACS is suspected. Delay in any of these advances simulated clock time toward myonecrosis.
Board pearl: Pain with passive stretch + tense compartment + escalating analgesia needs = clinical diagnosis sufficient for fasciotomy; pressure measurement confirms but should never delay surgery in obvious cases.
— CBC — baseline; thrombocytopenia raises bleeding-related ACS risk.
— BMP — baseline creatinine, potassium (hyperkalemia from myonecrosis), bicarbonate (acidosis).
— Creatine kinase (CK) — markedly elevated (>5,000 U/L; often >10,000) in rhabdomyolysis from myonecrosis; rising CK in serial draws is concerning.
— Urinalysis — heme-positive dipstick without RBCs = myoglobinuria.
— Urine myoglobin if available.
— Coagulation panel (PT/INR, aPTT) — especially in anticoagulated patients or pre-fasciotomy.
— Lactate — elevated in severe ischemia.
— Type and screen — pre-op preparation.
— Plain radiographs of the involved limb — identify fractures, dislocations, foreign bodies. Mandatory in trauma context.
— CT if high-energy trauma with concern for occult fracture or vascular injury.
— CT angiography or arterial duplex if pulses are diminished or asymmetric — rule out concurrent arterial injury, which can both mimic and complicate ACS.
— MRI has no role in acute diagnosis (too slow); used for chronic exertional compartment syndrome workup.
— Ultrasound — limited utility; cannot reliably measure compartment pressure.
Board pearl: A heme-positive UA with no RBCs on microscopy in a trauma or crush patient = myoglobinuria from rhabdomyolysis; check CK and start aggressive IV fluids while addressing the underlying compartment syndrome.
Step 3 management: Don't wait for labs to confirm before consulting surgery. Labs are obtained in parallel with clinical decision-making, not sequentially. The decision to perform fasciotomy is exam-driven; labs guide resuscitation, anesthesia planning, and complication surveillance.
— Obtunded, intubated, or sedated patient who cannot report pain.
— Pediatric or unreliable historian with high-risk injury.
— Equivocal clinical exam in a high-risk patient.
— Polytrauma with distracting injuries.
— Not required when clinical diagnosis is obvious — proceed directly to fasciotomy.
— Stryker intracompartmental pressure monitor (handheld) is the standard.
— Alternative: arterial line transducer connected to a side-port needle.
— Insert needle into the compartment of concern; measure all compartments of the involved segment (e.g., all 4 leg compartments — anterior, lateral, deep posterior, superficial posterior).
— Measure within 5 cm of the fracture site for highest yield (pressures fall off with distance).
— Absolute pressure >30 mmHg — traditional cutoff suggesting fasciotomy.
— Delta pressure (ΔP) = diastolic BP − compartment pressure ≤30 mmHg — preferred modern criterion (accounts for perfusion pressure); more specific, reduces unnecessary fasciotomy.
— ΔP ≤20 mmHg is widely accepted as a definitive surgical indication.
— Hypotensive patients have low diastolic BP → low ΔP threshold reached easily; resuscitate before relying on ΔP.
— Single measurement can miss evolving ACS — repeat or use continuous monitoring in obtunded patients.
— Needle outside the compartment, clot in the needle, or saline column issues give false readings.
Key distinction: Absolute pressure >30 mmHg is sensitive but not specific; ΔP ≤30 mmHg is the more clinically meaningful trigger and is preferred by orthopedic and trauma societies.
Board pearl: A patient with diastolic BP of 70 and compartment pressure of 45 mmHg has ΔP = 25 → fasciotomy indicated, even though absolute pressure is "only" 45.
— <4 hours ischemia: fully reversible.
— 4–6 hours: variable muscle injury, nerve dysfunction often reversible.
— >6–8 hours: irreversible myonecrosis, contracture risk (Volkmann's).
— >24 hours: fasciotomy may be contraindicated because opening a necrotic compartment releases toxic metabolites → hyperkalemia, myoglobinuria, sepsis; consider amputation instead.
— Obvious ACS clinically → fasciotomy without pressure measurement.
— High-risk + equivocal exam → measure pressures; ΔP ≤30 → fasciotomy.
— Low-risk + normal exam → serial exams every 1–2h, no measurement.
— Obtunded/unreliable patient + high-risk injury → measure pressures or place continuous monitor.
— Remove all circumferential dressings, casts, splints — bivalve cast and split underlying padding; this alone can drop pressure 50–85%.
— Position limb at heart level — elevation reduces arterial inflow and worsens perfusion gradient; dependent positioning increases edema.
— Supplemental oxygen to maximize tissue delivery.
— Aggressive IV crystalloid to maintain MAP and renal perfusion (rhabdomyolysis prophylaxis).
— Correct hypotension — hypotension worsens ΔP and accelerates ischemia.
— Hold anticoagulation if possible; reverse if active hemorrhage-induced ACS.
— Treat hyperkalemia if present.
— Adequate analgesia but recognize escalating need as warning, not endpoint.
Step 3 management: The single most important early intervention before surgery is complete release of circumferential constriction (cast, dressings, eschar). Many "developing" cases resolve once external compression is removed; failure to perform this is a board-favorite error.
CCS pearl: Order in this sequence: remove cast → position at heart level → IVF bolus → orthopedic consult → labs/imaging → OR booking. Skipping the cast step costs simulated time.
— Use opioids (morphine, hydromorphone, fentanyl) for pain control, but never rely on improved pain control as evidence of resolution — escalating need is a red flag.
— Avoid regional anesthesia/peripheral nerve blocks in suspected or evolving ACS — they mask the cardinal symptom (pain) and delay diagnosis.
— Epidural anesthesia in trauma patients with at-risk extremities is similarly discouraged.
— Isotonic crystalloid (normal saline or LR) at 1.5 mL/kg/h or higher; titrate to urine output ≥1–2 mL/kg/h to flush myoglobin.
— Avoid lactated Ringer's if severe hyperkalemia (small K+ load) — controversial; NS often preferred initially.
— Aggressive hydration is the cornerstone.
— Urinary alkalinization with sodium bicarbonate (target urine pH >6.5) — reduces myoglobin precipitation; evidence is mixed but commonly tested.
— Mannitol — controversial, not routine.
— Monitor CK, BMP, urine output, ABG q4–6h.
— Calcium gluconate for cardiac membrane stabilization if ECG changes.
— Insulin + dextrose, albuterol, sodium bicarbonate for intracellular shift.
— Loop diuretics if euvolemic; hemodialysis for refractory hyperkalemia or oliguric AKI.
— Not routine for ACS itself.
— Indicated for open fractures (cefazolin ± aminoglycoside per Gustilo-Anderson grade) and post-fasciotomy infection prophylaxis per surgical protocol.
— Tetanus prophylaxis for open wounds.
— Warfarin: vitamin K + 4-factor PCC.
— DOACs: andexanet alfa (factor Xa inhibitors) or idarucizumab (dabigatran).
— Heparin: protamine.
Board pearl: A patient with a femur fracture and rising compartment pressure has a regional nerve block ordered — this is the wrong answer. Nerve blocks mask the only reliable early symptom of ACS.
Step 3 management: Manage rhabdomyolysis aggressively in parallel with surgical decompression; the kidneys can be lost even after the limb is saved.
— Two-incision technique (standard):
— Lateral incision over the fibula → releases anterior and lateral compartments (avoid superficial peroneal nerve, which lies in the lateral compartment distally).
— Medial incision 2 cm posterior to the posteromedial tibia → releases superficial posterior and deep posterior compartments (protect saphenous vein/nerve).
— Single-incision (lateral parafibular) technique is an alternative.
— Volar (Henry approach) — releases volar compartment and decompresses the carpal tunnel (always release the carpal tunnel concurrently).
— Dorsal incision if dorsal/mobile wad compartments involved.
— Leave wounds open; cover with sterile saline-moistened gauze or negative-pressure wound therapy (wound VAC).
— Return to OR in 48–72 hours for re-look, debridement of nonviable muscle, and possible delayed primary closure or split-thickness skin grafting (STSG).
— Most wounds require STSG; some can close primarily with tension techniques.
— Fasciotomy may release myoglobin/potassium → cardiac arrest, AKI.
— Consider non-operative management and possible amputation for nonviable limb; multidisciplinary decision with vascular and trauma surgery.
CCS pearl: Order "OR, emergent — 4-compartment fasciotomy" with anesthesia, blood products available, and post-op ICU bed reservation for rhabdo/AKI monitoring.
Board pearl: Incomplete decompression (failure to release all four leg compartments) is a common cause of fasciotomy failure and persistent compartment syndrome.
— Lower baseline incidence of ACS due to less muscle mass and more elastic fascia, but outcomes are worse when it occurs.
— Atypical presentations: confusion, agitation, or refusal to participate in exam may be the only clues — especially in dementia or delirium.
— Polypharmacy (anticoagulants, antiplatelets) increases bleeding-related ACS risk after minor trauma.
— Frailty, cardiac comorbidities increase perioperative mortality from fasciotomy; still proceed — the alternative (limb loss, rhabdo, sepsis) is worse.
— Post-fasciotomy wound healing is slower; higher rates of STSG, infection, and DVT.
— Reduced renal reserve → rhabdomyolysis-induced AKI is more catastrophic.
— Lower threshold for early hemodialysis in refractory hyperkalemia or oligo-anuric AKI.
— Avoid nephrotoxic agents (NSAIDs, contrast when possible, aminoglycosides if alternative exists).
— Dose-adjust analgesics: morphine and its active metabolite (M6G) accumulate — use hydromorphone or fentanyl preferentially in CKD.
— Bicarbonate therapy for urinary alkalinization must be balanced against volume overload risk.
— Coordinate emergent dialysis pre- or post-fasciotomy as needed.
— AV fistula limb requires careful protection; avoid BP cuffs and IV access on that side.
— Coagulopathy from synthetic dysfunction increases bleeding-induced ACS risk and complicates fasciotomy hemostasis.
— Correct INR with FFP or 4-factor PCC and platelets pre-op if severely deranged.
— Avoid hepatically metabolized opioid load; fentanyl preferred.
— Albumin <2.5 g/dL predicts poor wound healing.
— Baseline neuropathy may mask early paresthesias.
— Higher infection risk post-fasciotomy; tight glycemic control perioperatively.
Step 3 management: In an elderly anticoagulated patient with a spontaneous calf hematoma and increasing pain, reverse anticoagulation, image with CT, measure compartment pressures, and consult surgery — don't dismiss as a simple bruise.
Board pearl: Atraumatic ACS in the elderly = anticoagulant-related hematoma until proven otherwise.
— Most common causes: supracondylar humerus fractures (forearm ACS → Volkmann's ischemic contracture), tibial fractures, forearm both-bone fractures, and IV infiltration in neonates/infants.
— Classic "P's" are unreliable in children.
— The "3 A's" of pediatric ACS — replaces pain assessment:
— Anxiety (increasing distress, inconsolability)
— Agitation
— Analgesic requirement increasing
— Children tolerate higher absolute compartment pressures briefly but suffer the same time-dependent damage.
— Lower threshold for pressure measurement under sedation when exam is unreliable.
— Supracondylar fracture + median nerve palsy + forearm pain = emergent reduction + possible fasciotomy to prevent Volkmann's contracture.
— Hypertonic or vasoactive infusions extravasating into a tight neonatal forearm/hand → ACS within hours.
— Inspect IV sites hourly in NICU patients.
— Rare; reported in lower extremities after prolonged lithotomy positioning (well-leg compartment syndrome during operative deliveries) or trauma.
— Avoid prolonged lithotomy >2–4 h; reposition periodically.
— Imaging considerations: plain X-rays with abdominal shielding acceptable; CT angiography only if clinically essential.
— Anesthesia for fasciotomy: regional/general per obstetric anesthesia consult; fetal monitoring during prolonged procedures after viability.
— Anticoagulation reversal in pregnant patients: vitamin K, PCC are safe; weigh fetal risks of any agent.
— Distinct entity; recurrent exercise-induced pain that resolves with rest.
— Diagnosis: post-exercise compartment pressures (>30 mmHg at 1 min post, or >20 mmHg at 5 min).
— Treatment: activity modification first; elective fasciotomy if refractory.
Key distinction: Acute compartment syndrome is a surgical emergency; chronic exertional compartment syndrome is an outpatient diagnosis with elective management — do not confuse the two on stems.
Board pearl: A toddler with a supracondylar fracture who becomes inconsolable despite splinting and acetaminophen needs immediate re-evaluation for forearm ACS — the 3 A's are the pediatric red flag.
— Late sequela of untreated forearm (or leg) ACS.
— Fibrosis and contracture of flexor muscles → fixed flexion deformity of wrist and fingers ("claw hand").
— Treatment is reconstructive (tendon transfer, contracture release) — prevention is the only effective strategy.
— CK often >10,000–100,000 U/L.
— Myoglobinuric AKI from heme pigment toxicity and tubular obstruction.
— Hyperkalemia, hyperphosphatemia, hypocalcemia, metabolic acidosis.
— May require RRT.
— Sensory loss, motor weakness, foot drop (deep peroneal), claw hand (median/ulnar).
— Chronic neuropathic pain syndromes.
— Open fasciotomy wounds at risk for bacterial colonization and deep infection.
— Necrotizing fasciitis can mimic or complicate ACS — high mortality.
— Required in late-presenting ACS with nonviable muscle, refractory sepsis, or failed reconstruction.
— Counseling and prosthetics referral.
— More common after delayed treatment or repeated surgery.
— Need for STSG, delayed closure, chronic ulceration, cosmetic disfigurement.
— Lymphedema, chronic venous insufficiency from disrupted venous return.
Board pearl: A delayed-presentation ACS patient who arrests during fasciotomy = reperfusion-induced hyperkalemia; pre-treat with calcium, insulin/dextrose, bicarbonate, and have dialysis ready before tourniquet release.
Step 3 management: Daily neurovascular checks, CK trends, BMP q6–12h, and wound assessment in the post-fasciotomy patient; start VTE prophylaxis as soon as bleeding risk allows.
— Suspected concurrent arterial injury (asymmetric pulses, abnormal ABI, expanding hematoma).
— Reperfusion ACS after revascularization.
— Anticipated need for STSG or complex soft-tissue reconstruction.
— Hand compartment syndrome (often co-managed).
— Circumferential burns requiring escharotomy in addition to fasciotomy.
— Severe rhabdomyolysis (CK >20,000) with AKI or hyperkalemia.
— Hemodynamic instability, vasopressor requirement.
— Multi-compartment or multi-limb fasciotomy.
— Post-operative monitoring after late-presenting ACS (reperfusion syndrome risk).
— Mechanical ventilation, ongoing resuscitation.
— Need for emergent or continuous renal replacement therapy.
— Community hospital without orthopedic/trauma coverage → transfer immediately to a Level I/II trauma center; do not delay for imaging beyond plain films.
— Stabilize: remove constricting dressings, IVF, analgesia, blood products en route.
— EMTALA requires that transfer be appropriate and that the receiving facility accept; ACS qualifies as an unstable emergency condition.
CCS pearl: Move the patient to "operating room" promptly; in CCS, leaving a patient on the ED floor with elevated compartment pressures accrues time penalty. Order "transfer to Level I trauma center" if appropriate resources are unavailable at the current location.
Step 3 management: Door-to-fasciotomy goal is <6 hours from symptom onset. Every system delay (waiting for orthopedist, OR booking, transfer) must be aggressively shortened — escalate up the chain of command if needed.
Board pearl: A small community ED without 24/7 orthopedic coverage must transfer suspected ACS patients emergently; observation is not appropriate.
— Sudden onset; classic 6 P's (pain, pallor, pulselessness, paresthesia, paralysis, poikilothermia) all early.
— Pulses absent, cold limb, demarcation line.
— Etiology: embolism (AF, post-MI mural thrombus), thrombosis on atherosclerotic plaque.
— Diagnostics: CT angiography or arterial duplex.
— Treatment: heparin, vascular surgery, embolectomy or thrombolysis.
— Key distinction: ACS preserves pulses; arterial occlusion eliminates them early.
— Unilateral swelling, calf tenderness, but no pain out of proportion, no tense compartment, no passive stretch pain.
— Diagnosis: venous duplex.
— Treatment: anticoagulation.
— Can rarely coexist with or trigger phlegmasia cerulea dolens.
— Massive iliofemoral DVT causing limb ischemia.
— Cyanotic, painful, swollen limb; pulses may be diminished.
— Treatment: anticoagulation, thrombolysis, possible thrombectomy.
— Warm, erythematous, tender skin; fever; no pain with passive stretch; soft compartment.
— Treatment: antibiotics.
— Pain out of proportion (overlap with ACS!), rapid progression, systemic toxicity, crepitus, bullae, "dishwater" drainage.
— LRINEC score supports diagnosis.
— Treatment: emergent surgical debridement, broad-spectrum antibiotics (vancomycin + piperacillin-tazobactam + clindamycin).
— Can mimic or coexist with ACS — surgical exploration distinguishes.
Board pearl: Pain out of proportion + systemic toxicity + skin changes (bullae, crepitus) = think necrotizing fasciitis, not just ACS — both require the OR, but the antibiotic and resuscitation plans differ.
Key distinction: Pulselessness early → arterial occlusion. Pulses preserved with tense compartment → ACS.
— Diabetic neuropathy, postherpetic neuralgia, radiculopathy.
— No tense compartment, chronic course, dermatomal distribution.
— Often post-injury; burning pain, allodynia, autonomic changes (temperature, color), trophic skin changes.
— Develops over weeks; not an acute compartment.
— Foot drop, paresthesias mimic anterior leg ACS, but no calf tenderness, no tense compartment, positive straight-leg raise, back pain history.
— Pit viper bites cause local swelling that can mimic but rarely cause true ACS.
— Pressure measurement before fasciotomy — antivenom (CroFab) usually resolves swelling without surgery.
— Unnecessary fasciotomy worsens outcome.
Key distinction: Snake envenomation swelling looks like ACS but rarely is — measure pressures and treat with antivenom first; fasciotomy is overused in this setting and worsens outcomes.
Board pearl: A patient with new foot drop after lumbar surgery and a soft, non-tender calf has L5 radiculopathy or peroneal nerve compression, not ACS; image the spine and assess positioning, don't measure compartment pressures.
Step 3 management: When the diagnosis is unclear, measure pressures rather than guessing — it is fast, definitive, and avoids both missed ACS and unnecessary fasciotomy.
— Day 0: Initial fasciotomy; wounds left open with NPWT or saline gauze; ICU monitoring for rhabdo/hyperkalemia.
— Day 2–3: Return to OR for re-look, debridement of nonviable muscle, possible delayed primary closure.
— Day 5–7: STSG if wounds cannot close primarily; harvest from anterolateral thigh typically.
— Day 7–14: Discharge planning if STSG taken, no infection, AKI resolved.
— Pain control: transition from IV opioids to oral; multimodal with acetaminophen + short-course oral opioid + gabapentin if neuropathic component. Provide opioid stewardship counseling and limited supply.
— VTE prophylaxis: continue enoxaparin or transition to oral agent for the immobilization period (typically 2–4 weeks or until ambulating).
— Antibiotics: complete prescribed course if infected; otherwise none.
— Tetanus booster if not current.
— Wound care supplies and dressing changes per plastic/ortho protocol.
— DMARDs/anticoagulants — resume home anticoagulation cautiously, typically after wound stability.
— Weight-bearing status per orthopedic surgeon (often non–weight-bearing if associated fracture).
— Assistive devices (crutches, walker, wheelchair).
— Splint or brace for support and contracture prevention.
— Physical therapy for ROM, strengthening, gait training.
— Occupational therapy for upper extremity fasciotomy patients.
— Prosthetics/orthotics if amputation occurred or foot drop persists (AFO).
— Chronic neuropathic pain → gabapentin, pregabalin, duloxetine, pain clinic referral.
— Persistent weakness → ongoing PT, tendon transfer surgery for Volkmann's if needed.
— Cosmetic concerns → plastic surgery follow-up.
— Anticoagulation review and dose optimization.
— Substance use counseling if "found down" was etiology.
— Athletic conditioning advice for CECS patients.
Step 3 management: A post-fasciotomy patient discharged on enoxaparin and oxycodone needs a follow-up appointment within 1–2 weeks, wound care instructions, return precautions for infection, and clear opioid taper plan.
Board pearl: Volkmann's contracture is irreversible without surgery — refer early to a hand surgeon when contracture begins to develop.
— Orthopedic surgery: 1–2 weeks post-discharge, then every 2–4 weeks until fracture/wound healed; longer for definitive fixation planning.
— Plastic surgery: if STSG performed, at 1 week, 1 month, 3 months.
— Primary care: 1–2 weeks post-discharge for medication reconciliation, pain control review, opioid management, mental health screen.
— Physical/occupational therapy: 2–3 sessions per week, ongoing.
— Nephrology: if AKI required dialysis or persistent renal dysfunction — 2 weeks post-discharge, then per nephrologist.
— BMP at 1 week post-discharge if AKI history; ensure recovery to baseline.
— CK trend until normalized.
— CBC if anticoagulated or had significant blood loss.
— Wound photographs at each visit to document healing.
— Neurologic exam: sensation, motor strength, reflexes at each visit; document recovery trajectory.
— Functional assessment: ROM, gait analysis, return-to-work or return-to-sport timelines.
— Return precautions: worsening pain, increasing wound drainage, fever, new numbness, dark urine, calf swelling (DVT), shortness of breath (PE).
— Wound hygiene and dressing change technique demonstration.
— Opioid risks: dependence, constipation, sedation; co-prescribe stool softener and bowel regimen.
— Smoking cessation — critical for wound healing, especially STSG and fracture union.
— Nutrition: protein-rich diet, vitamin C, zinc for wound healing.
— Mental health: screen for PTSD (trauma context), depression (functional loss); refer if positive.
— Driving: restricted while on opioids, in casts, or with limb dysfunction.
— Sedentary work: 2–6 weeks depending on extremity and fracture.
— Manual labor: 3–6 months.
— Contact sports: case-by-case, often 6–12 months.
Step 3 management: At the 1-week post-discharge visit, focus on wound check, opioid reassessment, VTE prophylaxis continuation, PT engagement, and mental health screening — Step 3 loves this multifaceted ambulatory follow-up question.
Board pearl: Persistent neuropathic pain at 3 months → start gabapentin or duloxetine and refer to chronic pain or physiatry.
— Fasciotomy is time-critical; if the patient is obtunded or unable to consent, proceed under emergency exception (implied consent) — document the emergent indication, time-sensitive nature, and inability to obtain consent.
— For pediatric patients, obtain consent from parent/guardian if available, but do not delay life- or limb-saving surgery; emergency doctrine applies.
— Counsel on cosmetic outcomes (large scars, STSG appearance), risk of nerve injury, amputation, and need for multiple surgeries — these are commonly under-disclosed.
— Missed or delayed ACS is one of the most common sources of orthopedic malpractice claims.
— Documentation is critical: timed serial exams, vital signs, analgesic doses, consultant communications, and the rationale for the surgical decision must all be recorded.
— Communicate clearly with consultants; document name, time, and recommendation of every phone call.
— Suspected non-accidental trauma in children (e.g., infant with unexplained extremity ACS) → report to child protective services per state law.
— Suspected elder abuse with prolonged immobilization or unwitnessed falls → adult protective services.
— Penetrating trauma (gunshot, stabbing) → law enforcement notification per state law.
— Handoff failure between ED and admitting team, or between shift changes, is a major cause of delayed diagnosis. Use structured handoff (e.g., I-PASS) and explicitly transfer concern for ACS with the next-exam time.
— Inter-hospital transfer: EMTALA mandates appropriate stabilization and acceptance by receiving facility; ACS is an unstable emergent condition requiring expedited transfer.
— OR availability conflicts: ACS supersedes elective cases; advocate aggressively for OR access.
— Provide FMLA and disability paperwork; coordinate with occupational health.
— Every missed or delayed ACS case should trigger M&M review and root-cause analysis.
Step 3 management: When a covering resident calls about a high-risk patient at change of shift, the responding physician should perform an in-person reassessment rather than relying solely on phoned-in description — this is a transition-of-care safety net.
Board pearl: "Pain out of proportion documented but not acted upon" is the single most common phrase in successful ACS malpractice plaintiff cases.
Board pearl: "Tense, painful calf in a 22-year-old male after tibial fracture, opioid-refractory" = fasciotomy, not more morphine.
Key distinction: Pulses preserved → ACS; pulses absent → arterial occlusion.
— 23-year-old male, motorcycle crash, tibial shaft fracture, casted 4 hours ago. Returns with severe pain unrelieved by morphine. Pain worsens with toe plantarflexion. Pulses present, foot warm.
— Best next step: Remove cast and measure compartment pressures (clinical diagnosis is sufficient — fasciotomy can be ordered without measurement).
— 45-year-old polytrauma, intubated and sedated, swollen tense calf. Cannot report pain.
— Best next step: Measure compartment pressures; ΔP ≤30 → fasciotomy.
— 7-year-old with supracondylar humerus fracture, casted in ED. Now inconsolable, requiring escalating opioids.
— Best next step: Remove cast and assess; emergent orthopedic re-evaluation for forearm ACS; pediatric 3 A's recognition.
— Found-down patient with 18-hour lower extremity ischemia, CK 80,000, K+ 6.8.
— Best next step: Resuscitate, treat hyperkalemia, urgent surgical evaluation — but recognize that fasciotomy after 24 h with established myonecrosis may be contraindicated; multidisciplinary discussion regarding amputation.
— 75-year-old on warfarin with minor calf trauma, INR 4.5, expanding hematoma, increasing pain.
— Best next step: Reverse warfarin with vitamin K + 4F-PCC; image; measure pressures; emergent surgical consultation.
— Patient with acute limb ischemia revascularized 2 hours ago; now developing tense calf and pain.
— Best next step: Reperfusion-induced ACS — emergent 4-compartment fasciotomy; vascular surgery aware.
— Rattlesnake bite, swollen forearm, severe pain.
— Best next step: Measure compartment pressure; give CroFab antivenom — fasciotomy is not first-line without elevated pressures.
— Stem describes textbook ACS; answer choices include "give more morphine" or "elevate limb above heart" — both wrong.
— Correct: remove cast, position at heart level, surgical consult.
Board pearl: Whenever a stem mentions pain disproportionate to exam, escalating analgesia, or tense compartment, the answer is almost always fasciotomy or pressure measurement — never "observation" or "MRI."
Step 3 management: On CCS, sequence: remove cast → IVF → ortho consult → OR → labs in parallel.
Acute compartment syndrome is a time-critical clinical diagnosis driven by pain out of proportion and pain with passive stretch in a tense compartment, confirmed by ΔP ≤30 mmHg when needed, and treated with emergent fasciotomy within 6 hours to prevent irreversible myonecrosis, nerve injury, rhabdomyolysis, and limb loss.
Board pearl: When in doubt, cut. A negative fasciotomy is forgivable; a missed compartment syndrome is not.