Posterior dislocation of total knee arthroplasty

Area of Science:

• Orthopedics
• Biomedical Engineering
• Surgical Complications

Background:

• Posterior dislocation of the prosthesis is a rare but severe complication following total knee arthroplasty.
• This complication can occur in both primary and revision total knee arthroplasty procedures.

Purpose of the Study:

• To review the management and outcomes of patients experiencing posterior dislocation after total knee arthroplasty.
• To identify predisposing factors and effective treatment strategies for this complication.

Main Methods:

• A retrospective review of seven patients treated for posterior dislocation after total knee arthroplasty between January 1985 and October 1989.
• Analysis of pre-arthroplasty limb alignment, extensor mechanism integrity, and joint stability.
• Individualized treatment approaches including closed reduction, patellar realignment, and component revision.

Main Results:

• All seven patients had identifiable issues with the knee extensor mechanism (patellar dislocation, tendon rupture, or fracture).
• Pre-arthroplasty limb alignment was valgus in all cases.
• Successful outcomes were achieved in six of the seven patients following individualized treatment, with no further dislocations reported, except in the case of patellar tendon rupture.

Conclusions:

• Posterior dislocation of total knee arthroplasty is associated with extensor mechanism dysfunction and potential ligamentous laxity.
• Individualized treatment, addressing both patellar tracking and ligamentous stability, is crucial for successful management.
• Surgical intervention, including component revision in cases of severe flexion instability, may be necessary.