ABOS Orthopaedic Surgery key terms

A five-type system describing fractures that involve the growth plate, based on which regions of the physis, metaphysis, and epiphysis are separated. Higher types carry greater risk of growth disturbance.

A bridge of bone forming across a damaged growth plate after injury or infection, tethering further growth and producing angular deformity or shortening. Treated by resection with interposition or by completion epiphysiodesis.

Surgical arrest of growth at a physis, either permanent (by drilling or curettage) or temporary (by staples or plates), used to correct leg-length discrepancy or angular deformity in a growing child.

The capacity of immature bone to correct angular deformity over time through asymmetric growth and appositional resorption. It is greatest in young children and in deformities near the physis in the plane of a joint's motion.

A system for ankle fractures based on the level of the fibular fracture relative to the distal tibiofibular syndesmosis: below (A), at (B), or above (C). Higher types imply greater syndesmotic instability.

A mechanistic scheme for ankle fractures named for foot position and direction of deforming force, such as supination-external rotation. It predicts the sequential pattern of ligamentous and bony injury about the ankle.

Disruption of the distal tibiofibular ligaments that normally hold the fibula to the tibia. It produces widening of the mortise, requires reduction and often screw or tightrope fixation, and can lead to chronic instability.

A four-grade system for femoral neck fractures based on displacement and angulation on anteroposterior radiograph. Higher grades indicate greater displacement and higher risk of avascular necrosis.

A system that grades femoral neck fractures by the angle of the fracture line from horizontal. Steeper angles create more shear and are more unstable, with higher rates of nonunion.

Death of bone from interruption of its blood supply, causing sclerosis, collapse, and joint destruction. Common sites include the femoral head, scaphoid, talus, and femoral condyles.

A four-part system for proximal humerus fractures defined by displacement of the head, shaft, and tuberosities. Treatment depends on the number of displaced parts and patient factors.

A fracture of the proximal ulna at the triceps insertion, often intra-articular and displaced by the pull of the triceps. Displaced fractures usually require tension-band wiring or plating.

A fracture of the proximal ulna with dislocation of the radial head. Recognition of the radial head dislocation is essential, and treatment requires anatomic ulnar reduction and radial head relocation.

A fracture of the distal radius with dislocation of the distal radioulnar joint. It is unstable and usually requires open reduction and internal fixation of the radius.

A distal radius fracture with dorsal displacement and angulation of the distal fragment, often from a fall on an outstretched hand. It may be associated with ulnar styloid fracture and later median nerve symptoms.

Elevated pressure within a closed fascial space that compromises capillary blood flow and threatens muscle and nerve viability. It presents with pain out of proportion and pain on passive stretch, and requires urgent fasciotomy.

Late sequelae of untreated forearm compartment syndrome, with fibrotic muscle shortening and fixed flexion deformity of the wrist and fingers, often with neuropathy. Prevention depends on early fasciotomy.

A complication after long bone fractures in which fat droplets enter the circulation, producing hypoxemia, petechiae, and neurologic changes, usually within days of injury. Treatment is supportive with early fracture stabilization.

A radiolucent shadow displaced by joint effusion on a lateral radiograph, most useful at the elbow. A posterior fat pad indicates occult intra-articular fracture even when no fracture line is visible.

A fracture of the distal humerus just above the condyles, most common in children after a fall. It risks neurovascular injury and compartment syndrome, and displaced fractures require prompt reduction and pinning.

A subtle spiral fracture of the tibial shaft in a young child who refuses to bear weight after minor trauma. Radiographs may be initially normal, and treatment is usually cast immobilization.

A grading system such as Gustilo-Anderson that categorizes open fractures by wound size, soft tissue injury, and contamination. Higher grades require more aggressive debridement and have higher infection risk.

Infection of bone, often bacterial, producing inflammation, bone destruction, and sometimes sequestrum formation. Acute hematogenous disease is common in children, while contiguous spread follows open fractures or surgery.

Bacterial infection of a joint space causing rapid cartilage destruction, with fever, joint pain, and refusal to move the limb. It is a surgical emergency requiring aspiration, irrigation, and antibiotics.

A Z-shaped diaphyseal osteotomy of the first metatarsal used to correct hallux valgus by translating and rotating the distal fragment. It allows powerful correction but risks troughing and transfer metatarsalgia.

Lateral deviation of the great toe with medial prominence of the first metatarsal head and often progressive deformity. Treatment ranges from shoe modification to osteotomy or arthrodesis depending on severity.

A V-shaped distal first metatarsal osteotomy for mild to moderate hallux valgus, with lateral translation of the head. It risks avascular necrosis of the metatarsal head and requires careful soft tissue handling.

Fibroproliferative thickening of the palmar fascia producing nodules and cords that cause fixed flexion of the digits, most often the ring and small fingers. Treatment includes injection, needle fasciotomy, or surgical excision.

Stenosing tenosynovitis of the flexor tendons at the first annular pulley, causing painful catching or locking of a digit. It is treated with corticosteroid injection or surgical pulley release.

Compression of the median nerve within the carpal tunnel producing numbness in the thumb, index, and middle fingers, night pain, and thenar weakness. Treatment includes splinting, injection, and surgical release.

Compression of the ulnar nerve as it passes through the ulnar tunnel at the wrist, causing sensory loss and intrinsic hand weakness. Causes include ganglion cysts and prolonged handlebar pressure.

A knee examination maneuver performed with slight flexion in which the tibia is translated anteriorly while the femur is stabilized. It is the most sensitive clinical test for anterior cruciate ligament insufficiency.

A knee maneuver in which the flexed knee is rotated and extended to trap and load a torn meniscus, producing a palpable or audible click with pain. It helps localize meniscal tears.

Surgical replacement of the torn anterior cruciate ligament with a tendon graft, typically through tunnels in the femur and tibia. It restores stability and aims to reduce secondary meniscal and cartilage injury.

A spectrum of abnormal hip development ranging from mild instability to frank dislocation, often detected by Ortolani and Barlow maneuvers in infancy. Early bracing is effective, while late cases need surgery.

A dynamic abduction orthosis used in infants with developmental dysplasia of the hip to hold the femoral head reduced and stimulate acetabular development. It requires monitoring for skin problems and failed reduction.

Displacement of the femoral head through the proximal physis in adolescents, presenting with hip or knee pain and limited internal rotation. Treatment is in situ screw fixation to prevent further slip.

Idiopathic avascular necrosis of the femoral head in children, causing pain, limp, and progressive head deformity. Treatment aims to contain the head within the acetabulum during healing.

Compression of the lumbar nerve roots below the spinal cord, producing saddle anesthesia, bowel or bladder dysfunction, and lower extremity weakness. It is a surgical emergency requiring urgent decompression.

Narrowing of the spinal canal or foramina that compresses nerve roots, causing neurogenic claudication relieved by flexion. Treatment ranges from activity modification to decompression with or without fusion.

Extrusion of nucleus pulposus through the annulus fibrosus, compressing an adjacent nerve root and causing radicular pain and weakness. Most improve with conservative care; persistent deficits may need discectomy.

A lateral curvature of the spine with vertebral rotation, classified as idiopathic, congenital, or neuromuscular. Treatment depends on curve magnitude and growth remaining, using bracing or fusion.

The angle measured between the most tilted end vertebrae of a spinal curve on a radiograph, used to quantify scoliosis severity and guide treatment decisions.