Chapter 41: Alterations of Musculoskeletal Function

Traumatic injuries encompass various fracture types classified by configuration and etiology, ranging from simple linear breaks to complex comminuted fractures and pathologic fractures through diseased bone. The healing cascade involves sequential phases of hematoma formation, inflammatory response, callus development, and ossification followed by bone remodeling, with potential complications including nonunion, delayed union, malunion, compartment syndrome, fat embolism, and rhabdomyolysis that can threaten limb viability and systemic stability. Related soft tissue injuries such as ligamentous sprains, tendinous strains, and avulsion injuries are addressed alongside overuse conditions including tendinitis and bursitis. Infections of bone tissue, particularly osteomyelitis caused predominately by Staphylococcus aureus, may spread through hematogenous, contiguous, or traumatic routes, producing characteristic pathological features such as sequestrum and involucrum formation. Metabolic bone diseases including osteoporosis, osteomalacia, rickets, and Paget disease represent disorders of bone mineral density, microarchitectural integrity, or remodeling dynamics influenced by nutritional deficiency, hormonal status, aging, and systemic illness. Joint pathology encompasses degenerative joint disease with cartilage loss and osteophyte formation alongside inflammatory arthritides including rheumatoid arthritis with its characteristic synovitis and pannus-mediated destruction, ankylosing spondylitis affecting axial skeleton with HLA-B27 association, gout precipitated by monosodium urate crystal deposition, and juvenile idiopathic arthritis in pediatric populations. Primary bone neoplasms including osteosarcoma, chondrosarcoma, and fibrosarcoma are contrasted with more prevalent metastatic disease from distant primary cancers. Skeletal muscle pathology encompasses dystrophic disorders from genetic mutations affecting structural proteins, inflammatory myopathies presenting with weakness and systemic manifestations, myoglobinuric rhabdomyolysis with acute renal injury risk, and fibromyalgia characterized by central sensitization mechanisms. This comprehensive framework integrates acute traumatic emergencies with chronic degenerative and metabolic conditions, autoimmune phenomena, and neoplastic processes affecting musculoskeletal tissues.