Iran Orthopedic Surgery Board Exam key terms

Bone remodels along the lines of mechanical stress it experiences, adding mass where loads are high and resorbing where they are low. It explains adaptive cortical thickening, stress shielding after rigid plating, and why disuse causes osteopenia.

Loss of bone density caused by a stiff implant carrying load that would otherwise pass through bone. It produces proximal femoral bone loss around fully coated stems and can complicate later revision surgery.

Compression across a growth plate slows its growth while tension accelerates it. This underlies guided growth with tension-band plates for angular deformity and explains physeal changes after malunion or tethering.

A five-type scheme describing fractures involving the growth plate by the structures crossed: physis alone, physis with metaphysis, physis with epiphysis, both, or physeal crush. Higher types carry greater risk of growth disturbance.

A bridge of bone forming across a damaged growth plate that tethers further growth and produces progressive angular deformity or shortening. It is treated by bar resection with interposition material or by completion epiphysiodesis.

Correcting angular deformity in a growing child by selectively restraining part of a physis, usually with a tension-band plate or staples on the convex side, allowing the remaining physis to straighten the limb.

A staged strategy in severely injured patients where the first operation controls hemorrhage, contamination, and fracture instability with external fixation and temporary closure, deferring definitive fixation until physiology has recovered.

The self-reinforcing cycle of hypothermia, acidosis, and coagulopathy that causes death after major trauma. Its presence dictates abbreviated surgery and intensive correction before any lengthy definitive procedure.

The concept that an initial injury primes the immune system so that a later insult, such as major surgery or infection, provokes a disproportionate inflammatory response and organ failure. It justifies timing operations carefully in polytrauma.

Raised pressure within a closed fascial compartment that compromises capillary perfusion and threatens muscle and nerve. It is diagnosed clinically by pain out of proportion and pain on passive stretch, and treated urgently by fasciotomy.

Surgical division of fascial envelopes to release compartment pressure. It must be complete, including all compartments, and is followed by wound management, often with delayed closure or skin grafting.

Failure of fixation of an implant without infection, driven by particle wear, macrophage-mediated osteolysis, and micromotion. It presents as progressive pain and radiolucent lines and is treated by revision arthroplasty.

Infection involving a joint replacement and its surrounding tissue, diagnosed by combined clinical, serologic, synovial, and microbiologic criteria. Management ranges from debridement with implant retention to staged exchange arthroplasty.

A structured community of bacteria adherent to a surface and encased in self-produced matrix, which shields them from antibiotics and host defenses. Its presence on implants explains persistence of infection and the need for implant removal in chronic cases.

Bone cement mixed with a heat-stable antibiotic, used for local drug delivery and to fill dead space. It is used in infected revision surgery and in some primary arthroplasties, with elution depending on cement type and porosity.

A fracture occurring near or around an orthopedic implant, usually after low-energy trauma in bone weakened by stress shielding or osteolysis. Treatment depends on implant stability and bone stock, ranging from fixation to revision.

A grading of soft-tissue injury in closed fractures, from grade 0 (minimal) through grade III (severe, with skin contusion, muscle crush, or vascular injury). It guides timing of fixation and predicts wound complications.

A three-tier grading of open fractures based on wound size, soft-tissue damage, and contamination, with subtypes for vascular injury. It predicts infection risk and guides antibiotics, debridement urgency, and fixation choice.

Surgical removal of devitalized tissue, foreign material, and contamination from a wound. In open fractures and infections it is repeated until the wound is clean, and adequacy strongly influences subsequent infection.

Infection of bone, often bacterial, producing inflammation, necrosis, and new bone formation. It may be acute hematogenous, contiguous, or chronic, and chronic disease requires debridement of necrotic bone plus targeted antibiotics.

A fragment of dead bone separated from living bone by infection and inflammation, often surrounded by new reactive bone. It harbors bacteria and must be surgically removed for chronic osteomyelitis to resolve.

New bone formed by periosteum around a focus of chronic osteomyelitis, often enclosing a sequestrum and draining through openings called cloacae. Its presence indicates long-standing infection with cortical destruction.

A surgical staging system for musculoskeletal tumors combining grade, anatomic compartment, and presence of metastases. Benign tumors are staged 1 to 3 and malignant tumors I to III, guiding resection margins and reconstruction.

Removal of a tumor with a cuff of normal tissue around it, beyond the reactive zone, so that no tumor is left behind. It is the standard oncologic margin for most sarcomas treated with limb salvage.

Resection of a bone or soft-tissue tumor with reconstruction of the defect, preserving the limb instead of amputating. It requires achievable margins, adequate soft-tissue cover, and a functional reconstruction such as a prosthesis or graft.

A fracture through bone weakened by a disease process such as tumor, cyst, or metabolic bone disease, often after minor trauma. Management addresses both the fracture and the underlying lesion, with fixation or reconstruction as needed.

Reduced bone mass and disrupted microarchitecture causing fragility fractures, defined by bone mineral density T-score of minus 2.5 or lower or by a fragility fracture. Treatment combines calcium, vitamin D, exercise, and antiresorptive or anabolic drugs.

A fracture caused by a fall from standing height or less, or by minimal trauma, in bone of reduced quality. It marks increased future fracture risk and should prompt evaluation and treatment for osteoporosis.

Breakdown of skeletal muscle releasing myoglobin and intracellular contents into blood, which can cause acute kidney injury and arrhythmia from hyperkalemia. It follows crush injury, prolonged immobility, or extreme exertion and requires aggressive fluids and monitoring.

Sustained compression of a body region causing muscle necrosis, swelling, and systemic release of myoglobin and potassium, sometimes with compartment syndrome. Management includes fluids, monitoring for renal failure, and timely decompression.

Measures to prevent clot formation after surgery or immobility, including early mobilization, mechanical compression, and pharmacologic anticoagulation chosen by risk. It is a core patient-safety practice in arthroplasty and trauma care.

Obstruction of pulmonary arteries by thrombus, usually migrating from deep veins of the legs or pelvis, causing dyspnea, chest pain, and right heart strain. It is a preventable cause of postoperative death.

A coordinated perioperative program using patient education, optimized analgesia, early feeding and mobilization, and reduced drains and catheters to shorten hospital stay and lower complications after major orthopedic surgery.

A patient's voluntary agreement to treatment after receiving and understanding information about the diagnosis, proposed procedure, alternatives, and material risks. It is an ethical and legal duty and must be documented before surgery.

A patient's ability to understand relevant information, appreciate the consequences of choices, reason about options, and communicate a decision. When capacity is absent, treatment proceeds through substituted judgment or legal representatives.

A situation where a secondary interest, such as financial gain or personal loyalty, could improperly influence professional judgment about patient care or research. It must be disclosed and managed, not merely avoided.

A hierarchical ranking of study design strength, from systematic reviews of randomized trials at the top to expert opinion and case reports at the bottom. It helps clinicians judge how much confidence to place in a recommendation.

A prospective study in which participants are randomly allocated to interventions, minimizing selection bias and allowing causal inference. Blinding, allocation concealment, and intention-to-treat analysis strengthen its validity.

Sensitivity is the proportion of truly diseased patients correctly identified by a test; specificity is the proportion of truly healthy patients correctly cleared. Both depend on the chosen threshold and help interpret diagnostic tests.