CAQ-Ortho cheat sheet

Compartment syndrome: the earliest and most reliable clinical sign is pain out of proportion to injury, worsened by passive stretch of the compartment muscles; pulselessness and paralysis are late findings.

Open fracture: antibiotics within 1 hour of arrival, tetanus prophylaxis, and urgent irrigation and debridement; Gustilo-Anderson grade I is <1 cm clean wound, grade III is >10 cm or heavily contaminated, IIIC requires vascular repair.

Salter-Harris physeal fracture types: I through the physis only; II through physis and metaphysis; III through physis and epiphysis; IV through metaphysis, physis, and epiphysis; V is a crush injury of the physis.

Anterior shoulder dislocation: axillary nerve injury is most common, assessed by deltoid sensation over the lateral shoulder; reduce with gentle traction, then obtain post-reduction radiographs.

Hip fracture: intracapsular fractures risk avascular necrosis of the femoral head from disruption of the medial femoral circumflex artery's retinacular branches; displaced fractures in the elderly are treated with arthroplasty.

Cauda equina syndrome: saddle anesthesia, urinary retention, bilateral leg weakness, and decreased anal tone require emergent MRI and surgical decompression; timing of decompression affects neurologic recovery.

Osteomyelitis: Staphylococcus aureus is the most common organism; chronic infection involves biofilm on necrotic bone requiring surgical debridement plus prolonged culture-directed antibiotics.

Tumor principles: the most common benign bone tumor is osteochondroma; the most common primary malignant bone tumor is osteosarcoma, typically in the metaphysis of the distal femur or proximal tibia in adolescents.

Fat embolism syndrome: after long bone fractures, presents with hypoxemia, petechiae, and confusion, typically 24-72 hours after injury; treatment is supportive with oxygen and stabilization.

Knee ligament examination: anterior drawer and Lachman test assess the ACL (Lachman is more sensitive in acute injury); the posterior drawer assesses the PCL; the McMurray test assesses meniscal tears.

Nerve injuries in knee dislocation: the common peroneal nerve is most commonly injured, causing foot drop and decreased sensation over the dorsum of the foot; the popliteal artery is also at risk.

Developmental dysplasia of the hip: Ortolani maneuver reduces a dislocated hip (clunk), Barlow maneuver dislocates a reducible hip; ultrasound is the screening test in infants under 6 months.

Legg-Calve-Perthes disease: idiopathic avascular necrosis of the femoral head in children aged 4-8 years, presenting with a limp and groin pain; treatment aims to contain the femoral head within the acetabulum.

Slipped capital femoral epiphysis: adolescent with hip or knee pain and an externally rotated gait; frog-leg lateral radiograph shows the slip; treatment is in situ screw fixation, and bilateral involvement is common.

Osteoarthritis: weight-bearing radiographs show joint space narrowing, subchondral sclerosis, osteophytes, and subchondral cysts; management begins with exercise, weight loss, and analgesics before arthroplasty.

Rheumatoid arthritis: symmetric polyarthritis of small joints with prolonged morning stiffness, elevated ESR and CRP, and anti-cyclic citrullinated peptide antibodies; early disease-modifying antirheumatic drugs prevent erosion.

Carpal tunnel syndrome: median nerve compression causes nocturnal paresthesias in the thumb, index, and middle fingers; Phalen and Tinel tests are provocative; thenar atrophy indicates advanced disease.

Dupuytren contracture: palmar fibromatosis causing flexion contracture of the metacarpophalangeal and proximal interphalangeal joints, most often the ring and small fingers; treatment is fasciectomy or collagenase injection.

Distal radius fractures: Colles fracture is dorsal displacement and angulation of the distal fragment; Smith fracture is volar displacement; a Barton fracture involves the dorsal or volar rim with carpal subluxation.

Scaphoid fracture: tenderness in the anatomic snuffbox; initial radiographs may be normal, so immobilization and repeat imaging or MRI are required because of the risk of nonunion and avascular necrosis.

Elbow dislocation: the brachial artery and median nerve are at risk; assess the radial pulse and perform a careful neurovascular examination before and after reduction.

Supracondylar humerus fracture in children: the anterior humeral line should intersect the middle third of the capitellum; displacement risks brachial artery and anterior interosseous nerve injury.

Rotator cuff tear: painful arc and weakness in abduction and external rotation; the drop arm test suggests a massive tear; younger patients with acute full-thickness tears are candidates for repair.

Adhesive capsulitis: painful progressive loss of both active and passive glenohumeral motion, especially external rotation; associated with diabetes mellitus; treatment is physical therapy and intra-articular corticosteroid injection.

Anterior cruciate ligament tear: acute hemarthrosis after a noncontact pivoting injury; the pivot shift and Lachman tests are positive; reconstruction is considered in active patients with instability.

Meniscal tear: joint line tenderness and mechanical symptoms such as locking or catching; degenerative tears in older adults are often treated with physical therapy rather than arthroscopy.

Achilles tendon rupture: sudden pop with weakness of plantar flexion; the Thompson test (squeeze the calf, absent plantar flexion) confirms the diagnosis; treatment is operative or functional bracing.

Pediatric bone healing: the physis is weaker than the ligament, so ligamentous injuries in children often present as physeal fractures; remodeling potential is greatest in younger children and near the physis.

Bone healing phases: inflammation (days), soft callus (weeks), hard callus (months), and remodeling (months to years); smoking, diabetes, and infection impair union.

Osteoporosis: dual-energy x-ray absorptiometry T-score of -2.5 or lower defines osteoporosis; fragility fractures of the hip, spine, and wrist are the classic sites; bisphosphonates reduce fracture risk.

Spinal cord injury: the ASIA impairment scale grades A through E; spinal shock causes transient flaccidity and areflexia; neurogenic shock is hypotension with bradycardia from loss of sympathetic tone.

Septic arthritis: joint aspiration showing a white blood cell count above 50,000 per microliter with a predominance of neutrophils suggests infection; Staphylococcus aureus is the most common organism; urgent drainage and antibiotics are indicated.

Gout: negatively birefringent needle-shaped monosodium urate crystals; pseudogout has positively birefringent rhomboid calcium pyrophosphate crystals; acute attacks are treated with anti-inflammatory therapy.

Paget disease of bone: increased alkaline phosphatase with normal calcium and phosphate; bone expands with a cotton-wool appearance; complications include pathologic fracture, deafness, and osteosarcoma.

Bone metastases: most commonly from prostate, breast, lung, kidney, and thyroid; lesions are typically osteolytic except prostate, which is often osteoblastic; pathologic fracture risk guides prophylactic fixation.

Prosthetic joint infection: presents with pain, swelling, and elevated ESR and CRP; diagnosis by joint aspiration with culture and synovial fluid analysis; treatment is debridement with implant retention or staged exchange.

ATLS approach to the polytrauma patient: primary survey of airway, breathing, circulation, disability, and exposure precedes orthopaedic intervention; life-threatening hemorrhage and pelvic ring disruption are addressed first.

Pelvic fracture: an unstable pelvic ring with hemodynamic instability is managed with a pelvic binder and angiography or preperitoneal packing; the mortality rate is high with associated hemorrhage.

Open fracture classification: Gustilo-Anderson type I is a clean wound under 1 cm, type II is 1-10 cm without extensive soft tissue damage, and type III is over 10 cm or with severe soft tissue injury.

Fat embolism and deep vein thrombosis prophylaxis: low-molecular-weight heparin after major lower extremity trauma or arthroplasty, with mechanical prophylaxis when anticoagulation is contraindicated.

Amputation: the level is determined by viable tissue and functional potential; a below-knee amputation preserves the knee for better energy efficiency than an above-knee amputation.

Compartment pressure: a resting pressure above 30 mmHg, or a diastolic pressure minus compartment pressure below 30 mmHg, supports fasciotomy in the appropriate clinical setting.

Nerve injury classification: neurapraxia is a conduction block with recovery expected; axonotmesis involves axonal injury with intact endoneurium and spontaneous recovery; neurotmesis is complete transection requiring repair.

Bone graft options: autograft is the gold standard for osteoconduction, osteoinduction, and osteogenesis; allograft provides osteoconduction with less donor site morbidity but carries disease transmission risk.

Fracture fixation principles: absolute stability with compression plating or lag screws for articular fractures; relative stability with intramedullary nailing or bridging plates to promote callus formation.

Osteoarthritis of the knee: nonoperative treatment includes exercise, weight loss, acetaminophen, topical or oral nonsteroidal anti-inflammatory drugs, and corticosteroid injections; total knee arthroplasty is for end-stage disease with failed conservative care.

Total hip arthroplasty: indications include disabling pain with radiographic arthritis, avascular necrosis, and displaced femoral neck fracture in the elderly; aseptic loosening and periprosthetic fracture are late complications.

Hip fracture management: displaced femoral neck fractures in older adults are treated with hemiarthroplasty or total hip arthroplasty; intertrochanteric fractures are treated with intramedullary nailing or a sliding hip screw.

Ankle fracture: the Danis-Weber classification is based on the level of the fibular fracture relative to the syndesmosis; the Ottawa ankle rules guide when radiographs are needed.

Lisfranc injury: tarsometatarsal disruption with widening between the first and second metatarsal bases; a weight-bearing radiograph or CT confirms the diagnosis; unstable injuries require surgical fixation.

Osteonecrosis of the femoral head: risk factors include corticosteroids, alcohol, sickle cell disease, and trauma; early stages may be treated with core decompression, while collapse requires arthroplasty.

Bone tumors: osteosarcoma shows a sunburst periosteal reaction and Codman triangle; Ewing sarcoma occurs in the diaphysis of children and is associated with a translocation; both require neoadjuvant chemotherapy and wide resection.

Fracture description: document the bone, location, fracture pattern (transverse, oblique, spiral, comminuted), displacement, angulation, and articular involvement; open versus closed status is essential.

Splinting principles: immobilize the joint above and below the fracture; pad bony prominences; assess neurovascular status before and after splinting; a posterior splint is used for distal radius fractures.

Compartment syndrome of the leg: the anterior compartment is most commonly affected; fasciotomy of all four compartments is required; delay risks muscle necrosis and Volkmann contracture.

Osteomyelitis of the diabetic foot: polymicrobial infection is common; deep wound cultures rather than superficial swabs guide antibiotics; vascular assessment is essential before debridement.

Carpal bone injuries: the scaphoid is the most commonly fractured carpal bone; the lunate is the most commonly dislocated carpal bone, and perilunate dislocation requires urgent reduction.

Elbow fractures in adults: the radial head is the most common elbow fracture; a mechanical block to forearm rotation after a non-displaced fracture may require excision or replacement.

Tendon injuries: the Achilles tendon is the most commonly ruptured tendon; the extensor mechanism of the knee can rupture after total knee arthroplasty or in patients with diabetes or renal disease.

Bone infection and hardware: infected internal fixation often requires hardware removal after fracture union; stable union with retained hardware may be managed with suppressive antibiotics.

Rehabilitation principles: early range of motion prevents stiffness while protecting fixation; weight-bearing status depends on the stability achieved, not on the time since surgery alone.

Shoulder dislocation: anterior dislocation is most common, with the arm held in abduction and external rotation; posterior dislocation is associated with seizures and presents with the arm in internal rotation and a lightbulb sign on the axillary radiograph.

Hip dislocation: posterior dislocation after a dashboard injury presents with the leg shortened, adducted, and internally rotated; anterior dislocation presents with the leg externally rotated; urgent reduction reduces the risk of avascular necrosis.

Knee dislocation: a multiligament injury with a high risk of popliteal artery injury; ankle-brachial index below 0.9 or asymmetric pulses warrant CT angiography.

Compartment syndrome of the forearm: supracondylar fracture or a tight cast can cause it; pain with passive finger extension is an early sign; urgent fasciotomy is required.

Osteoarthritis of the hand: Heberden nodes at the distal interphalangeal joints and Bouchard nodes at the proximal interphalangeal joints; the first carpometacarpal joint is commonly involved.

Trigger finger: stenosing tenosynovitis of the flexor tendon sheath causing catching at the A1 pulley; corticosteroid injection is first-line, and surgical release is for refractory cases.

De Quervain tenosynovitis: pain over the radial styloid with a positive Finkelstein test; involves the abductor pollicis longus and extensor pollicis brevis tendons in the first dorsal compartment.

Ganglion cyst: the most common soft tissue mass of the hand, arising from a joint capsule or tendon sheath; aspiration or observation is reasonable, and recurrence after aspiration is common.

Nerve entrapment: cubital tunnel syndrome involves the ulnar nerve at the elbow with numbness of the small finger and intrinsic hand weakness; the elbow flexion test is provocative.

Pediatric fractures: greenstick and torus (buckle) fractures occur because children's bones are more porous; complete remodeling often occurs with growth, reducing the need for anatomic reduction.

Non-accidental trauma: suspicious patterns include fractures in nonmobile infants, metaphyseal corner fractures, posterior rib fractures, and injuries inconsistent with the stated mechanism; reporting is mandatory.

Scoliosis: adolescent idiopathic scoliosis is assessed with the Adam forward bend test and Cobb angle measurement; curves of 25-40 degrees in a growing child are treated with bracing, and surgery is considered above 45-50 degrees.

Clubfoot: the Ponseti method involves serial casting, percutaneous Achilles tenotomy, and foot abduction bracing; treatment is most effective when started in the first weeks of life.

Osteogenesis imperfecta: recurrent fractures with blue sclerae, dentinogenesis imperfecta, and hearing loss; caused by type I collagen defects; treatment includes bisphosphonates and intramedullary rodding.

Achondroplasia: the most common cause of short-limbed dwarfism, from an FGFR3 mutation; features include frontal bossing, rhizomelic shortening, and foramen magnum stenosis.

Bone tumors in children: osteochondroma is the most common benign lesion; osteosarcoma and Ewing sarcoma are the most common primary malignant bone tumors, with peak incidence in the second decade.

Sports medicine: Osgood-Schlatter disease is traction apophysitis of the tibial tubercle in adolescents; treatment is activity modification and stretching, with symptoms resolving after physeal closure.

Anterior knee pain: patellofemoral syndrome is managed with quadriceps and hip strengthening; patellar dislocation is associated with a torn medial patellofemoral ligament and predisposing anatomy.

Spinal stenosis: neurogenic claudication relieved by sitting or leaning forward, unlike vascular claudication which is relieved by standing still; MRI confirms canal narrowing; surgery is for progressive symptoms or cauda equina syndrome.

Lumbar disc herniation: radicular pain in a dermatomal pattern; the L4-L5 disc typically affects the L5 root, and L5-S1 affects the S1 root with decreased ankle reflex; most cases improve with conservative care.

Cervical myelopathy: gait instability, hand clumsiness, hyperreflexia, and a positive Hoffmann sign; MRI shows cord compression; surgical decompression prevents progression.

Vertebral compression fracture: osteoporotic fractures cause midline back pain; radiographs show wedging; treatment includes analgesia, bracing, and osteoporosis management, with vertebroplasty considered for refractory pain.

Spinal cord injury: high-dose corticosteroids are not routinely recommended; early immobilization, prevention of pressure injury, and venous thromboembolism prophylaxis are priorities.

Herniated nucleus pulposus: an extruded fragment is a surgical emergency only with cauda equina syndrome or progressive motor deficit; otherwise, observation and physical therapy are first-line.

Spinal fusion: indications include instability, deformity, and degenerative disease with failed conservative care; pseudarthrosis presents with persistent pain and hardware failure.

Osteoid osteoma: a benign bone tumor causing night pain relieved by nonsteroidal anti-inflammatory drugs; imaging shows a radiolucent nidus with surrounding sclerosis; treatment is ablation or excision.

Multiple myeloma: lytic bone lesions, anemia, hypercalcemia, and renal failure with elevated protein electrophoresis; vertebral compression fractures are common; bisphosphonates reduce skeletal events.

Septic arthritis of a native joint: the knee is most commonly affected; patients hold the joint in a position that maximizes volume; aspiration before antibiotics is essential, and Staphylococcus aureus is the most common organism.

Prosthetic joint infection: acute infection within weeks of surgery may be treated with debridement and implant retention; chronic infection requires staged exchange with an antibiotic spacer.

Osteomyelitis: acute hematogenous infection in children affects the metaphysis of long bones; MRI is sensitive for early detection; treatment is prolonged antibiotics with surgical drainage when an abscess is present.

Necrotizing fasciitis: severe pain out of proportion, rapidly spreading erythema, crepitus, and systemic toxicity; immediate surgical debridement and broad-spectrum antibiotics are required.

Gas gangrene: caused by Clostridium perfringens after contaminated wounds; crepitus and rapid myonecrosis; treatment is urgent debridement and antibiotics, with hyperbaric oxygen as an adjunct.

Antibiotic prophylaxis: a first-generation cephalosporin is given within 1 hour before incision for arthroplasty; vancomycin is added for methicillin-resistant Staphylococcus aureus colonization.

Lyme arthritis: caused by Borrelia burgdorferi from a tick bite; monoarticular knee swelling with a history of erythema migrans; serologic testing and doxycycline are indicated.

Tuberculous spondylitis: Pott disease causes vertebral body destruction and kyphosis; constitutional symptoms and a positive interferon-gamma release assay support the diagnosis; treatment is prolonged multidrug therapy.

Diabetic foot infection: assess for osteomyelitis with a probe-to-bone test and radiographs; vascular status determines healing potential; multidisciplinary care reduces amputation rates.

Fracture healing assessment: clinical union is the absence of tenderness and motion at the fracture site; radiographic union shows bridging callus across the fracture on at least three cortices.

Nonunion: failure to heal by 6-9 months with no progression; risk factors include smoking, infection, instability, and poor blood supply; treatment is revision fixation with bone grafting.

Malunion: healing in an unacceptable position causing deformity or functional limitation; treatment is corrective osteotomy if symptoms warrant.

Bone graft and bone substitutes: autograft from the iliac crest provides osteogenic cells; allograft and synthetic substitutes provide osteoconduction but lack osteoinduction.

Ilizarov technique: distraction osteogenesis for limb lengthening and deformity correction; regenerate bone forms in the distraction gap; complications include pin site infection and joint contracture.

Amputation rehabilitation: a prosthesis is fitted after wound healing and edema control; a rigid dressing or shrinker sock prepares the residual limb; early mobilization improves outcomes.

Complex regional pain syndrome: disproportionate pain, swelling, and skin changes after trauma; diagnosis is clinical; treatment includes physical therapy, sympathetic blocks, and analgesia.

Heterotopic ossification: bone formation in soft tissue after trauma or surgery, especially after acetabular fracture or traumatic brain injury; prophylaxis with indomethacin or radiation reduces risk.

Stress fractures: common in the tibia, metatarsals, and femoral neck in runners and military recruits; the femoral neck and anterior tibial cortex are high-risk sites requiring restricted weight-bearing.

Wound management in open fractures: irrigate with normal saline, remove gross contamination, and cover the wound with a sterile dressing; definitive debridement occurs in the operating room.

Nerve examination: document motor and sensory function before and after any reduction or splinting; the radial nerve is injured with humeral shaft fractures, and the axillary nerve with shoulder dislocations.

Vascular examination: check pulses, capillary refill, and skin color; a pulseless limb after fracture requires urgent reduction and vascular assessment; hard signs of arterial injury warrant immediate exploration.

Tourniquet use: a tourniquet controls life-threatening extremity hemorrhage; note the application time and release when definitive care is available; avoid prolonged inflation to prevent nerve injury.

Fasciotomy technique: perform through full-thickness skin and fascial incisions over all compartments; leave wounds open with dressing changes and plan delayed closure or skin grafting.

Trauma resuscitation: permissive hypotension is used in hemorrhagic shock until hemorrhage control; massive transfusion protocols balance packed red blood cells, plasma, and platelets.

Damage control orthopaedics: temporary external fixation of long bone fractures in unstable polytrauma patients limits surgical insult; definitive fixation follows once the patient is stabilized.

Open joint injuries: an intra-articular fracture with a wound communicating with the joint requires urgent irrigation, debridement, and antibiotics; a saline load test can confirm communication.

Amputation versus limb salvage: the decision depends on the extent of soft tissue and bone loss, nerve injury, ischemia time, and patient factors; scoring systems support but do not replace clinical judgment.

Bone density and fracture risk: FRAX estimates 10-year probability of major osteoporotic and hip fracture; treatment thresholds vary by age and prior fracture history.

Calcium and vitamin D: adequate intake supports bone health; vitamin D deficiency is common in fracture patients and should be corrected before elective surgery.

Anticoagulation and surgery: direct oral anticoagulants are typically held before elective arthroplasty per agent-specific intervals; neuraxial anesthesia timing requires attention to these intervals.

Periprosthetic fracture: occurs around hip or knee arthroplasty, often after a fall; treatment depends on implant stability and bone stock, ranging from fixation to revision arthroplasty.

Aseptic loosening: progressive radiolucent lines around the implant with pain on weight-bearing; diagnosis of exclusion after infection is ruled out; treatment is revision arthroplasty.

Dislocation after total hip arthroplasty: risk factors include posterior approach, small femoral head, and component malposition; closed reduction is attempted, with revision for recurrent instability.

Venous thromboembolism after arthroplasty: prophylaxis is standard; symptoms include calf pain, swelling, and dyspnea; duplex ultrasound and CT angiography confirm the diagnosis.

Surgical site infection prevention: preoperative chlorhexidine bathing, appropriate antibiotic timing, normothermia, and glycemic control reduce infection risk.

Osteoporosis treatment: bisphosphonates, denosumab, and anabolic agents such as teriparatide reduce fracture risk; a drug holiday is considered after long-term bisphosphonate use.