An Overuse Injury of the Throwing Elbow
- Olecranon stress fracture is an OVERUSE injury that primarily affects THROWING athletes (baseball pitchers, javelin) and athletes exposed to high repetitive compressive loads such as gymnasts; the incidence is rising with year-round youth sport, so it should be considered in any thrower with persistent posterior elbow pain.
- The mechanism is VALGUS EXTENSION OVERLOAD: repetitive forced elbow extension combined with valgus stress during the throwing motion drives the olecranon against the olecranon fossa (posteromedial impingement) and applies repetitive triceps traction, so the posteromedial olecranon is loaded cyclically until a stress reaction and then a stress fracture develop.
- The presentation is POSTERIOR elbow pain that is worse on extension and with throwing (and may be associated with reduced velocity/performance); examination shows posterior/posteromedial tenderness and pain on forced extension, and there may be signs of associated valgus extension overload such as a posteromedial osteophyte.
- There are two recognised PATTERNS: in the skeletally immature, a PERSISTENT (non-united, widened) OLECRANON PHYSIS - effectively a physeal stress injury that fails to fuse - and in the adult, an OBLIQUE STRESS FRACTURE LINE through the olecranon; recognising which pattern is present guides treatment.
- Plain radiographs are often NORMAL early, so MRI (showing marrow oedema/stress reaction before a line is visible) or CT is frequently required for definitive diagnosis; it is also essential to assess for VALGUS INSTABILITY and ulnar collateral ligament (UCL) insufficiency, because UCL laxity increases posteromedial load and an unaddressed UCL problem predisposes to recurrence.
- MANAGEMENT is REST and activity modification for early stress reactions and many fractures, but advanced or established pathology - a persistent physis or a complete/non-union stress fracture, or the need to return an ELITE thrower reliably - often requires SURGICAL FIXATION (a tension-band construct or, commonly in throwers, an intramedullary compression SCREW, with bone grafting for non-union), together with addressing any UCL/valgus instability.
- “Olecranon stress fracture = overuse in THROWERS (and gymnasts) via VALGUS EXTENSION OVERLOAD; posterior elbow pain worse on extension.
- “Two patterns: adolescent PERSISTENT OLECRANON PHYSIS vs adult OBLIQUE stress line; plain films often normal early -> MRI/CT.
- “Always assess UCL/valgus instability; rest for early, surgical fixation (tension band or intramedullary screw) for established/non-union or elite return.
A thrower with posterior elbow pain worse on extension; valgus extension overload. Plain films may be normal - get an MRI/CT.
Assess the UCL / valgus instability - posteromedial overload and recurrence relate to it, and it may need treating alongside the fracture.
Mechanism, Patterns & Diagnosis
Olecranon stress fracture is an overuse injury of throwing athletes (and gymnasts) produced by valgus extension overload: repetitive forced elbow extension with valgus drives the olecranon against its fossa (posteromedial impingement) and applies cyclical triceps traction until a stress reaction and then a fracture develop. The patient has posterior elbow pain that is worse on extension and with throwing, with posteromedial tenderness. There are two patterns - the adolescent persistent (non-united) olecranon physis and the adult oblique stress line. Plain radiographs are often normal early, so MRI (marrow oedema) or CT confirms the diagnosis, and it is essential to assess for valgus instability / UCL insufficiency, which loads the posteromedial elbow and predisposes to recurrence if unaddressed.
Management
- Rest and activity modification for stress reactions and many stress fractures - a structured throwing programme guides graded return to play.
- Surgical fixation for advanced/established pathology - a persistent olecranon physis, a complete or non-union stress fracture, or to reliably return an elite thrower: a tension-band construct or, commonly in throwers, an intramedullary compression screw, with bone grafting for non-union.
- Address valgus instability / UCL. Because UCL insufficiency increases posteromedial load, evaluate and, where indicated, treat (UCL reconstruction) to prevent recurrence.
- Prevent recurrence. Manage throwing volume/mechanics; persistent or recurrent pain warrants re-evaluation for non-union or unrecognised valgus instability.
Two pitfalls recur with olecranon stress fracture. First, a NORMAL plain radiograph does not exclude it: early the film is often normal, so a thrower with persistent posterior elbow pain on extension needs an MRI or CT rather than reassurance, because a missed stress fracture can progress to a complete fracture or non-union. Second, do not treat the olecranon in isolation: VALGUS INSTABILITY / UCL insufficiency loads the posteromedial elbow, drives valgus extension overload, and is a cause of recurrence, so the UCL must be assessed and addressed where indicated. Treating the bone while ignoring the ligament and the throwing load is a recipe for recurrence.
Evidence & Key Studies
Olecranon Stress Fracture
- Olecranon stress fractures are a rare upper-extremity fracture that primarily affects throwing athletes, with rising incidence (especially in the paediatric population) as sport participation and volume increase.
- Their vague presentation makes diagnosis and management challenging, so careful evaluation of the disease process, diagnosis and treatment is important.
- MRI is highlighted as part of the work-up of the throwing/overuse elbow injury.
Stress reactions and fractures around the elbow in athletes
- Athletes in throwing sports and those with high repetitive/compressive loads (e.g. gymnastics) are particularly susceptible to elbow stress injuries; susceptible bones include the olecranon process (and distal humerus, coronoid, sublime tubercle, radial head).
- Diagnosis can sometimes be made on history, examination and radiography, but MRI is often required for definitive diagnosis.
- The mainstay of management is rest and activity modification, with surgical management often required for advanced pathology to achieve successful resolution and return to play.
According to PubMed, the predominance in throwing athletes, the rising (especially paediatric) incidence and the vague presentation come from the cited Greif review; the susceptibility of throwers and high-load athletes (gymnasts), the olecranon as a susceptible site, the frequent need for MRI when radiographs are unrevealing, and the rest-mainstay-with-surgery-for-advanced-pathology approach from the cited McBride review. The valgus- extension-overload mechanism, the adolescent persistent-physis versus adult oblique-line patterns, the link to UCL/valgus instability and the specific fixation constructs (tension band / intramedullary screw) are standard, well-established teaching. (See also our Valgus Extension Overload and Ulnar Collateral Ligament Injury topics.)
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A baseball pitcher has posterior elbow pain worse on extension and throwing, with normal radiographs. What is your diagnosis and work-up?”
“How would you treat an olecranon stress fracture in a competitive thrower?”
Mnemonics & Memory Aids
OLECRANON
Hook:OLECRANON: Overuse, valgus Loading, Extension pain, CT/MRI, Rest early, Adolescent vs Adult patterns, Non-union fix, Operate for elite, Note the UCL.
Who & mechanism
- Overuse in throwing athletes (baseball/javelin) and gymnasts
- Valgus extension overload: posteromedial impingement + triceps traction
- Rising incidence with year-round youth sport
Presentation & patterns
- Posterior elbow pain worse on extension and throwing; posteromedial tenderness
- Adolescent: persistent (non-united) olecranon physis
- Adult: oblique stress fracture line
Diagnosis
- Plain films often normal early
- MRI (stress reaction/marrow oedema) or CT (line) for definitive diagnosis
- Assess valgus instability / UCL insufficiency
Management
- Rest + activity modification + graded throwing programme for early disease
- Surgical fixation (intramedullary screw or tension band; graft for non-union) for established/elite return
- Address UCL/valgus instability; modify throwing load/mechanics