The "50% rule" in arthroscopic and orthopaedic surgery

Area of Science:

• Orthopaedic Surgery
• Sports Medicine
• Musculoskeletal Research

Background:

• The "50% rule" is frequently applied to guide treatment decisions for partial tears of tendons and ligaments.
• Its widespread use suggests a need to evaluate its scientific basis and historical evolution.

Purpose of the Study:

• To investigate the origins and validity of the "50% rule" in arthroscopic and orthopaedic surgery.
• To assess the scientific evidence supporting its application across various musculoskeletal injuries.

Main Methods:

• A comprehensive PubMed search was conducted, identifying 1,039 relevant articles.
• The literature review focused on the "50% rule" in hand flexor tendon lacerations, anterior cruciate ligament tears, rotator cuff tears, and biceps tendon injuries.

Main Results:

• The "50% rule" appears to have originated in hand surgery literature.
• Its application has extended to other orthopaedic conditions, often without strong scientific justification.
• Limited scientific data supports the rule's efficacy for diverse partial tendon and ligament injuries.

Conclusions:

• The "50% rule" is a subjective criterion used by surgeons for managing common orthopaedic conditions.
• There is minimal scientific evidence to validate the widespread and often arbitrary use of the "50% rule" in clinical practice.