A 35-year-old tennis player has chronic lateral elbow pain, worse with resisted wrist extension and gripping. Tenderness is maximal at the origin of extensor carpi radialis brevis (ECRB) on the lateral epicondyle. The pathological process in this condition is best described as:
- A Acute inflammatory tendinitis with neutrophil infiltration
- B Partial-thickness avulsion fracture of the lateral epicondyle apophysis
- C Compression neuropathy of the posterior interosseous nerve in the radial tunnel
- D Angiofibroblastic hyperplasia (tendinosis/degenerative tendinopathy) with disorganised collagen and vascular proliferation without inflammation ✓
Explanation
Lateral epicondylitis (tennis elbow) is histologically characterised by angiofibroblastic hyperplasia (Nirschl lesion) — disorganised fibroblastic and vascular proliferation, collagen disarray, and mucoid degeneration within the ECRB origin without the inflammatory cells typical of acute tendinitis. It is therefore more accurately termed tendinosis or tendinopathy. This distinction is clinically important: anti-inflammatory injections have limited long-term efficacy because the pathology is degenerative, not inflammatory. Radial tunnel syndrome presents with pain more distal (proximal forearm) and no weakness of wrist extension.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.