Scaphoid exostosis causing rupture of the flexor pollicis longus

Area of Science:

• Orthopedic Surgery
• Rheumatology
• Hand Surgery

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease primarily affecting joints.
• RA can lead to various complications, including tenosynovitis and tendon rupture.
• Scaphoid osteophytes are bony outgrowths from the scaphoid bone, often associated with arthritis.

Observation:

• A case report details a patient with rheumatoid arthritis presenting with an attrition rupture of the flexor pollicis longus (FPL) tendon.
• The rupture was attributed to a scaphoid osteophyte impinging on the FPL tendon.
• The lesion was identified only after a meticulous exploration of the carpal tunnel floor.

Findings:

• This case highlights a rare cause of flexor pollicis longus tendon rupture: attrition by a scaphoid osteophyte in the context of rheumatoid arthritis.
• The mechanical irritation and abrasion caused by the osteophyte led to the tendon's eventual rupture.
• Diagnostic challenges were noted, emphasizing the importance of thorough intraoperative examination.

Implications:

• This finding expands the differential diagnosis for FPL tendon rupture in patients with rheumatoid arthritis.
• It underscores the need for surgeons to consider bony impingement from osteophytes as a cause of tendon attrition.
• Early recognition and management of such impingements may prevent tendon rupture and preserve hand function.