ABOS Orthopaedic Sports Medicine key terms

A compression fracture of the posterolateral humeral head created when the head impacts the anterior glenoid rim during anterior shoulder dislocation; its size and orientation influence engagement risk and surgical decision-making.

Detachment of the anteroinferior labrum and attached capsule from the glenoid rim, typically after anterior dislocation. It is the most common structural cause of recurrent anterior shoulder instability.

The arc of the glenoid surface that contacts the humeral head through motion; a Hill-Sachs lesion extending medial to this track is off-track and predicts engaging instability.

Injury to the superior labrum extending from anterior to posterior, often involving the biceps anchor. It may cause deep shoulder pain, painful clicking, and reduced throwing performance.

Transfer of the coracoid process with its attached conjoint tendon to the anterior glenoid neck to restore bone stock and create a sling effect in recurrent anterior shoulder instability.

Painful, progressive loss of glenohumeral motion caused by capsular inflammation and fibrosis, with characteristic loss of external rotation; often associated with diabetes and thyroid disease.

Advanced glenohumeral arthritis with superior humeral head migration and cuff deficiency, producing pseudoparalysis and a femoralized head; reverse total shoulder arthroplasty is often indicated.

Repetitive throwing creates tensile stress medially and compressive stress laterally and posteriorly in the elbow, causing posteromedial osteophytes, chondral injury, and loose bodies.

The primary medial stabilizer of the elbow against valgus stress, running from the medial epicondyle to the sublime tubercle; injured by repetitive throwing and reconstructed with a tendon graft.

Rotatory subluxation of the forearm away from the humerus due to injury of the lateral collateral ligament complex, tested by the pivot-shift and chair-push-up tests.

Compression or traction of the ulnar nerve at the elbow, causing medial elbow pain, ring- and small-finger numbness, and intrinsic hand weakness; worsened by prolonged elbow flexion.

Degenerative tendinopathy at the common extensor origin, chiefly the extensor carpi radialis brevis, causing lateral elbow pain with resisted wrist extension and gripping.

Disruption of the scapholunate interosseous ligament allowing abnormal widening and rotation of the scaphoid and lunate, producing wrist pain, weakness, and eventual carpal collapse if untreated.

Injury to the triangular fibrocartilage complex on the ulnar side of the wrist, causing ulnar-sided pain, clicking, and instability with rotation or weight bearing.

Stenosing tenosynovitis of the first dorsal compartment, affecting the abductor pollicis longus and extensor pollicis brevis tendons; radial wrist pain worsens with thumb motion and ulnar deviation.

Acute rupture of the ulnar collateral ligament of the thumb metacarpophalangeal joint after a fall on an abducted thumb; instability requires surgical repair, especially with a Stener lesion.

Avulsion of the flexor digitorum profundus tendon from its insertion at the distal phalanx, usually of the ring finger, leaving the patient unable to flex the distal interphalangeal joint.

A break through the carpal bone bridging the proximal and distal rows, most often at the waist, with radial wrist pain and snuffbox tenderness; retrograde blood supply raises nonunion and avascular necrosis risk.

Abnormal contact between the proximal femur and acetabular rim during motion, from cam or pincer morphology, causing labral and chondral damage and groin pain in young active patients.

Chronic groin pain from injury to the rectus abdominis, adductor, and pelvic floor attachments, often coexisting with hip pathology; also called sports hernia despite no true hernia.

Audible or palpable hip clicking from iliotibial band or iliopsoas tendon movement over bony prominences; usually painful only when inflamed, and distinguished from intra-articular causes.

Surgical replacement of a torn anterior cruciate ligament with autograft or allograft tissue to restore tibial restraint and rotational stability; graft choice affects healing and return-to-sport timelines.

Peripheral meniscal tear at the meniscocapsular junction of the medial meniscus, often accompanying ACL injury; it may be missed on MRI and is repaired to restore stability.

Structures stabilizing the knee against varus and external rotation, including the lateral collateral ligament, popliteus, and popliteofibular ligament; injury causes a positive dial test.

A focal lesion of subchondral bone and overlying cartilage, most common in the knee of adolescents, that can cause pain, mechanical symptoms, and loose-body formation if unstable.

Subluxation or dislocation of the patella, usually lateral, driven by trochlear dysplasia, patella alta, and ligamentous laxity; recurrent episodes damage the medial patellofemoral ligament.

Disruption of the distal tibiofibular ligaments causing high ankle pain, widening of the mortise, and prolonged recovery compared with lateral sprains; tested by squeeze and external rotation.

Transverse fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal, in a watershed vascular zone; prone to nonunion and treated with protected weight bearing or fixation.

Disruption of the tarsometatarsal joint complex, often from a twisting or crush injury, causing midfoot pain, swelling, and instability; missed injuries lead to chronic deformity.

Degenerative, load-related condition of the Achilles tendon causing morning stiffness, pain with activity, and thickened tendon; managed with progressive eccentric or heavy-slow-resistance exercise.

A stress fracture of the pars interarticularis, usually at L5, causing activity-related low back pain that improves with rest; common in adolescent extension athletes.

Transient unilateral shooting arm pain and weakness from stretching or compression of the brachial plexus or nerve root during contact sport; symptoms usually resolve within minutes.

Temporary spinal cord dysfunction after neck compression, producing bilateral tingling, weakness, and sometimes transient quadriparesis without fracture; return to collision sport requires careful evaluation.

A traumatic brain injury from impulsive forces causing functional rather than structural disturbance, with headache, imbalance, cognitive change, and sleep symptoms; management is relative rest followed by stepwise return.

A system describing physeal fractures by their involvement of the growth plate, metaphysis, and epiphysis; types III to V carry greater risk of growth disturbance.

Time-dependent behavior of tissues such as ligament and tendon, showing creep under sustained load and stress relaxation, plus rate-dependent stiffness; central to rehabilitation loading and graft choice.

The biologic process by which a tendon graft revascularizes, remodels, and regains mechanical strength after ligament reconstruction, passing through necrosis, cellular repopulation, and remodeling phases.

The ratio of recent training load to a longer-term average, used to estimate injury risk; sharp spikes, often above about 1.5, are associated with higher injury rates.

Objective hop, jump, and strength tests comparing limbs to quantify readiness after injury; used with symptoms and psychological measures to guide return to sport rather than a fixed timeline.

Low-load exercise with a tourniquet cuff producing partial arterial and venous occlusion, increasing metabolic stress and muscle hypertrophy; useful when high loads are contraindicated after surgery.