Musculoskeletal disorders 

Heterotopic ossification (HO) is the abnormal formation of mature lamellar bone within soft tissues where bone does not normally exist. It most commonly develops after musculoskeletal trauma, fractures, burns, spinal cord injury, traumatic brain injury, or orthopaedic surgical procedures, particularly around major joints.

Chronic low back pain (CLBP) is defined as pain localized between the lower rib margin and the gluteal folds that persists for more than 6 weeks. It may occur with or without leg pain (sciatica) and represents one of the leading causes of long-term disability worldwide. Unlike acute low back pain, chronic pain often involves a combination of structural pathology, persistent inflammation, central pain sensitization, psychological factors, and functional impairment.

Hypocholecalciferolemia, commonly referred to as vitamin D deficiency, is a disorder characterized by inadequate serum concentrations of 25-hydroxyvitamin D [25(OH)D], resulting in impaired calcium and phosphate homeostasis. Persistent deficiency leads to defective bone mineralization, causing rickets in children and osteomalacia in adults. Vitamin D deficiency also contributes to osteoporosis, muscle weakness, falls, and fragility fractures, particularly among older adults.

Osteoporotic vertebral compression fractures (VCFs) are among the most common fragility fractures in older adults, particularly postmenopausal women and elderly men with osteoporosis. They occur when weakened vertebral bodies collapse under normal physiological loads or after minimal trauma. Although osteoporosis is the leading cause, vertebral compression fractures may also result from metastatic malignancy, multiple myeloma, infection, or prolonged corticosteroid therapy.

Post-open reduction and internal fixation (ORIF) infection and post-arthroplasty infection are serious healthcare-associated musculoskeletal infections that occur following orthopaedic implant surgery. These infections involve bacterial colonization of implants, surrounding soft tissues, and bone, often resulting in biofilm formation that makes eradication difficult. If left untreated, they may lead to implant loosening, fracture non-union, chronic osteomyelitis, prosthesis failure, sepsis, limb loss, and death.