Closed manipulation after total knee arthroplasty: outcome and affecting variables

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Rehabilitation Medicine

Background:

• Total knee arthroplasty (TKA) is a common procedure for end-stage knee osteoarthritis.
• Arthrofibrosis and stiffness can limit range of motion (ROM) after TKA, necessitating interventions like manipulation under anesthesia (MUA).
• Predictors of successful MUA outcomes require further elucidation to optimize patient selection and treatment protocols.

Purpose of the Study:

• To identify predictors of successful outcomes following manipulation in primary total knee arthroplasty (TKA).
• To evaluate the impact of various patient and surgical factors on ROM gains after manipulation.
• To assess the long-term functional recovery at 1-year follow-up post-manipulation.

Main Methods:

• Retrospective analysis of clinic records for 767 primary TKAs with 37 manipulations.
• Studied factors included patient demographics, preoperative ROM, surgical details (lateral release, implant type), and manipulation timing.
• Outcome measures were ROM gains (extension and flexion) and 1-year follow-up ROM.

Main Results:

• Patients achieved an average gain of 4° extension and 22° flexion, with mean 1-year ROM of 1° extension and 105° flexion.
• Manipulation was most effective within 8 weeks, in patients with full extension and <90° preoperative flexion, and those who had a lateral release.
• Outcomes were less favorable for patients with large flexion contractures, with only 67% regaining full extension.

Conclusions:

• Manipulation is a successful intervention for restoring flexion and function in TKA patients with varying degrees of stiffness.
• Early intervention (within 8 weeks) and intraoperative lateral release are key factors for maximizing ROM gains.
• While generally effective, patients with significant flexion contractures may have a reduced potential for regaining full extension.