Elbow instability

Area of Science:

• Orthopedic Surgery
• Biomechanics
• Musculoskeletal Research

Background:

• Elbow instability encompasses a spectrum from subluxation to dislocation.
• Understanding the clinical and pathological features is crucial for effective treatment.
• A unified classification system is needed to address these aspects.

Purpose of the Study:

• To present a classification system for elbow instability.
• To elucidate the common mechanism of posterolateral rotational displacement.
• To guide treatment strategies based on stability following reduction.

Main Methods:

• Classification of elbow instability based on clinical and pathological features.
• Analysis of the common mechanism of dislocation (posterolateral rotational displacement).
• Evaluation of treatment principles for acute dislocations with fractures, emphasizing ligamentous repair for early motion.

Main Results:

• Posterolateral rotational displacement is identified as the common mechanism.
• Treatment for acute dislocations is determined by stability after reduction.
• Recurrent instability often results from lateral ulnar collateral ligament (LUCL) insufficiency.

Conclusions:

• A unified classification aids in understanding and managing elbow instability.
• Prerequisites for ulnohumeral stability include intact joint surfaces and specific collateral ligaments.
• Reconstruction of the LUCL is effective for recurrent instability; chronic dislocations may require joint resurfacing.