Soft Tissue Lengthening for Flexion Dislocation of Patella

Area of Science:

• Orthopedics
• Sports Medicine
• Biomechanics

Background:

• Obligatory patellar dislocation, or habitual dislocation, is a rare form of patellofemoral instability.
• Characterized by the patella dislocating with every knee flexion due to quadriceps muscle contracture.
• Distinct from recurrent lateral patellar dislocation, it involves lateral soft tissue contracture, not medial disruption.

Purpose of the Study:

• To review the existing literature on the pathophysiology of obligatory patellar dislocation.
• To explore current and historical treatment strategies for this condition.
• To highlight the unique biomechanical factors contributing to habitual patellar dislocation.

Main Methods:

• Literature review of studies on obligatory patellar dislocation.
• Analysis of pathophysiology and treatment outcomes.
• Synthesis of information on surgical interventions and their efficacy.

Main Results:

• Obligatory dislocation often presents in children during ambulation, characterized by painless lateral patellar displacement.
• The underlying cause is lateral soft tissue contracture, contrasting with medial soft tissue issues in recurrent dislocations.
• Successful management typically requires a combination of soft tissue release/lengthening with proximal and distal reconstructive procedures.

Conclusions:

• Soft tissue lengthening has been a cornerstone of treatment for over 50 years.
• Combined procedures with careful intraoperative assessment are crucial for optimal outcomes.
• Further research with standardized measures is needed to define the optimal treatment algorithm.