Manipulation Under Anesthesia is Safe After Cementless Total Knee Arthroplasty: A Multicenter Study

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Rehabilitation Medicine

Background:

• Cementless total knee arthroplasty (TKA) relies on osseointegration for durable bone-implant fixation.
• Postoperative stiffness may necessitate manipulation under anesthesia (MUA) within 4-12 weeks, overlapping with the critical osseointegration period.
• The impact of early MUA on cementless fixation requires investigation.

Purpose of the Study:

• To evaluate the effect of early MUA on cementless TKA fixation.
• To compare functional outcomes and survivorship between cementless and cemented TKAs undergoing MUA.
• To assess MUA-related complications in both TKA groups.

Main Methods:

• A propensity-matched cohort study compared 100 cementless TKAs with 100 cemented TKAs that underwent MUA within 90 days of primary surgery.
• Patients were matched based on age, gender, BMI, and surgical year.
• Outcomes included MUA-related complications, postoperative Knee Injury and Osteoarthritis Outcome Scores (KOOS), and SF-12 scores.

Main Results:

• MUA-related complication rates were similar between cementless and cemented TKA groups (P=.324).
• No perioperative loosening of tibial or femoral components occurred in either group.
• Postoperative KOOS (P=.101) and SF-12 Mental scores (P=.380) were comparable, with 6-year survivorship at 98.0% for both.

Conclusions:

• Early MUA following cementless TKA is safe and does not increase complications or negatively impact patient-reported outcomes.
• Cementless TKA demonstrates durable bone-implant interface fixation, comparable to cemented TKA, even with early MUA.
• These findings support the use of cementless TKA with early MUA for managing postoperative stiffness.