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Mangled Extremity Severity Score (MESS)
Score based on skeletal/soft tissue injury, ischemia, shock, age. Ischemia >6 h doubles points. MESS ≥7 → amputation likely. Adjunct tool; not absolute.
Open topicMayo Classification — Olecranon Fractures
Type I: nondisplaced (A noncomminuted / B comminuted). Type II: displaced but stable (A/B). Type III: displaced and unstable (A/B). Type I conservative; II–III usually require fixation; III needs stability restoration.
Open topicMedial Clavicle Physeal Injury (Pseudodislocation) — Pattern
Physeal separation of medial clavicle mimics SCJ dislocation — the physis is weaker than ligaments in children. Posterior displacement threatens mediastinal structures — requires urgent reduction (often operative). CT is essential to distinguish true SCJ dislocation from physeal injury.
Open topicMega Prosthesis — Indications & Complications
Used for segmental bone loss after tumor resection or non-oncologic massive defects (failed revision arthroplasty, periprosthetic fractures). Common sites: distal femur replacement (DFR), proximal tibia, proximal femur replacement (PFR), proximal humerus. Advantages: immediate stability, early mobilization; modular designs allow intra-op flexibility. Complications: infection, aseptic loosening, soft tissue failure (extensor mechanism in proximal tibia), mechanical breakage. Long-term survivorshi...
Open topicMeniscal Tears — Basics
Red‑red (peripheral) zone heals best; red‑white intermediate; white‑white avascular. Vertical longitudinal (bucket handle) tears in young → repair; complex/degenerative tears in older → debride selectively. Clinical tests: McMurray, Thessaly; MRI is sensitive but clinical correlation vital. Repair techniques: all‑inside, inside‑out, outside‑in; address concomitant ACL tears. Meniscal preservation reduces risk of OA; root tears need repair to restore hoop stress.
Open topicMeniscal Tears — Types & Repair
Menisci are fibrocartilaginous structures aiding load transmission, stability, and lubrication. Types: longitudinal, horizontal, radial, flap, bucket handle, complex. Clinical: joint line tenderness, locking, McMurray/Apley tests positive. Imaging: MRI is gold standard (sensitivity >90%). Treatment: preserve meniscus if possible; repair (inside-out, outside-in, all-inside) or partial meniscectomy.
Open topicMeniscus Repair vs Meniscectomy
Meniscus vital for load transmission, shock absorption, joint stability. Repair preferred when possible (red-red, red-white tears, vertical longitudinal). Meniscectomy indicated for irreparable, degenerative tears. Repair techniques: inside-out, outside-in, all-inside devices. Meniscectomy → ↑ risk of OA long term.
Open topicMetastatic Bone Disease
Most common malignant tumor of bone overall. Primary sources: breast, prostate, lung, kidney, thyroid. Lesions: breast (mixed), prostate (blastic), lung/kidney/thyroid (lytic). Sites: spine, pelvis, proximal femur/humerus. Investigations: X-ray, MRI, CT chest/abdomen, bone scan/PET. Management: systemic therapy, bisphosphonates/denosumab, prophylactic fixation (Mirel’s >8), radiotherapy, spinal stabilization.
Open topicMetatarsal & Phalangeal Fractures
1st metatarsal fractures affect medial column; greater functional impact. 5th metatarsal: distinguish avulsion (zone 1), Jones (zone 2), and diaphyseal stress (zone 3). Multiple metatarsals/malalignment → operative fixation to restore parabola. Toe phalangeal fractures usually non-op; intra‑articular big toe injuries may need fixation. Athletes with Jones/stress fractures often benefit from early fixation.
Open topicMeyers–McKeever (± Zaricznyj) — Tibial Spine (ACL Avulsion)
Type I: Minimally displaced avulsion. Type II: Hinge of posterior fibers intact (anterior lift) — may reduce closed; fixation if interposed tissue. Type III: Completely displaced fragment — requires reduction and fixation. Type IV (Zaricznyj): Comminuted fragment — fixation with sutures/screws after debridement.
Open topicMilch / Jakob–Weiss — Lateral Condyle Humerus Fractures
Milch Type I: Fracture line lateral to trochlear groove (through capitellum–trochlear junction) — more stable. Milch Type II: Fracture line extends into trochlea — less stable (risk of displacement). Jakob/Weiss Displacement Staging: I (
Open topicModular Mega-prosthesis — Knee
Used after wide resection of distal femur/proximal tibia tumors. Modular systems allow intraoperative flexibility and immediate stability. Expandable designs used in children to accommodate growth. Advantages: early mobilization, good function; Disadvantages: high cost, infection risk. Survival: 70–80% implant survival at 10 years; complications include loosening, mechanical failure.
Open topicModular Taper Junctions & Trunnionosis
Trunnionosis = corrosion/wear at head–neck modular junction of THA. Mechanism: fretting + crevice corrosion, leading to metal ion release. Clinical: unexplained pain, swelling, adverse local tissue reaction (ALTR). Diagnosis: ESR/CRP to rule out infection; elevated cobalt/chromium; MRI (MARS) for pseudotumor. Management: revision with ceramic heads, titanium sleeves; avoid further corrosion.
Open topicMorton’s Neuroma
Perineural fibrosis of the common plantar digital nerve—classically in the 3rd webspace—causing burning plantar forefoot pain. Provocative tests: web‑space compression, Mulder’s click (palpable snap with medial–lateral squeeze), sensory symptoms into adjacent toes. Initial management is non‑operative: wide toe‑box shoes, metatarsal pads, activity modification; steroid injections provide short‑term relief; ultrasound‑guided ablation/PRP considered. Failure of conservative care → neurectomy of the...
Open topicMulti-ligament Knee Injury
Involves disruption of ≥2 major knee ligaments; often from high-energy trauma. Common patterns: ACL + PCL ± collateral injuries. Associated with vascular (popliteal artery) and nerve (common peroneal) injuries. Diagnosis: clinical + MRI; check vascular status with ABI, Doppler, CTA. Management: emergent reduction, vascular repair if injured, staged ligament reconstruction.
Open topicMultiple Myeloma — Orthopaedic View
Most common primary malignant bone tumor in adults (median age ~65 yrs). Neoplastic proliferation of plasma cells → monoclonal immunoglobulin production. Classical CRAB features: hyperCalcemia, Renal failure, Anemia, Bone lesions. Radiology: multiple punched-out lytic lesions, diffuse osteopenia. Diagnosis: SPEP/UPEP (M protein, Bence-Jones), bone marrow biopsy (>10% plasma cells). Ortho role: prophylactic fixation of impending fractures (Mirel’s >8), spinal decompression, bisphosphonates, verte...
Open topicMultiple Myeloma & Plasmacytoma
Most common primary malignant tumor of bone (plasma cell dyscrasia). CRAB features: hyperCalcemia, Renal failure, Anemia, Bone lesions (lytic). X‑ray: punched‑out lytic lesions, diffuse osteopenia, vertebral collapse. Diagnosis: serum/urine electrophoresis (M‑protein), bone marrow plasma cells >10%. Treatment: systemic chemotherapy (bortezomib, lenalidomide, dexamethasone), bisphosphonates, SCT in eligible patients.
Open topicMusculoskeletal Infections — Algorithm
Spectrum: cellulitis, abscess, septic arthritis, osteomyelitis. Principles: Early recognition, debridement, targeted antibiotics, stabilization, soft‑tissue cover. Diagnosis algorithm: suspect → labs (WBC, ESR, CRP) → imaging (X‑ray, MRI) → aspiration/biopsy for culture → tailored therapy. Surgical principles: remove necrotic tissue, maintain stability, provide vascularized soft‑tissue coverage. Antibiotics: empiric broad‑spectrum → targeted based on culture, prolonged course in bone infections.
Open topicMyositis Ossificans
Heterotopic ossification in muscle after trauma or neurological injury. Common sites: quadriceps, brachialis, adductors. Symptoms: painful swelling → hard mass, ↓ROM. Radiology: peripheral calcification with central lucency (zoning). Treatment: rest, NSAIDs, physio; excision after maturation (>6–12 mo).
Open topicNavicular & Cuboid Fractures
Tarsal navicular: body, tuberosity, and stress fractures; critical for medial column length and talonavicular congruity. Cuboid: 'nutcracker' fracture from forefoot abduction; lateral column length is key. Imaging: weight-bearing AP/lat/oblique + CT; MRI for stress fractures. Indications for surgery: displacement >2 mm, articular incongruity, medial/lateral column shortening, and instability with Lisfranc involvement. Fixation: screws/mini-plates for navicular; bridging plate/ex-fix for cuboid r...
Open topicNerve Entrapments — Cubital Tunnel Syndrome
Second most common compression neuropathy after CTS; affects ulnar nerve at elbow. Symptoms: paresthesias in ulnar digits, weakness of intrinsic hand muscles. Tests: Tinel’s at elbow, elbow flexion test, Froment’s sign, Wartenberg’s sign. Investigations: NCS/EMG confirm slowed conduction across elbow. Management: activity modification, splinting; surgical decompression/transposition if persistent.
Open topicNonunion — Weber & Cech Classification
Viable (hypertrophic/oligotrophic) vs non‑viable (atrophic, necrotic, defect, comminuted). Radiographic callus indicates biology; absence suggests poor biology. Guides treatment: stability alone for viable; add graft/biologics for non‑viable. viable → improve stability; nonviable → improve stability + add biology.
Open topicNonunion & Bone Transport — Ilizarov
Ilizarov fixator allows bone transport for segmental loss. Principle: distraction osteogenesis by gradual tension on callus. Indications: infected nonunion, bone loss, deformity correction. Protocol: latency 5–7 days, distraction 1 mm/day (0.25×4). Complications: pin site infection, joint stiffness, regenerate problems.
Open topicNuclear Medicine — Bone Scan & PET Basics
Bone scan = radionuclide (Tc-99m MDP) uptake proportional to osteoblastic activity. Highly sensitive for metastasis, stress fractures, infection, AVN. PET (FDG-PET): measures metabolic activity (glucose uptake). PET superior for staging malignancy, differentiating benign vs malignant lesions. Limitations: false positives (arthritis, trauma, infection).
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