Failure Incidence and Predictors Following Manipulation Under Anesthesia for the Stiff Total Knee Arthroplasty.

Abstract

Manipulation under anesthesia (MUA) is a common treatment for stiffness following total knee arthroplasty (TKA). The purpose of this study was to evaluate the outcomes following MUA and identify risk factors for additional surgical intervention. This study analyzed 227 knees that underwent MUA following primary TKA with one-year follow-up. The 39 patients (17.2%) who required additional intervention were compared to 174 patients who underwent MUA without further interventions. There were no differences in body mass index, American Society of Anesthesiologists class, and prior knee surgeries. The mean follow-up was 38.5 months (range, 12 to 119.5) in the failure group and 39.2 (range, 12 to 124.2) in the control cohort. Of the 39 patients requiring additional procedures, 29 (74%) underwent arthroscopic lysis of adhesions and 15 (38%) revision TKA. Range of motion (ROM) two weeks following MUA was lower in patients who had additional interventions (96.4 versus 107.4°, P < 0.001), as was ROM at one year (103.1 versus 112.9°, P < 0.001). Multivariate analyses found age, cruciate-retaining (CR) implants, and ROM two weeks after MUA as independently associated with failure. There were no differences in preoperative Knee Society Score (KSS) Function, KSS Knee, and Knee Injury and Osteoarthritis Score for Joint Replacement (KOOS JR) scores. At the latest follow-up, patients who failed MUA had inferior KSS Knee (79.1 versus 89.0, P = 0.003), KOOS JR (65.0 versus 80.2, P < 0.01), Forgotten Joint Score (FJS-12) (39.1 versus 62.0, P < 0.01), and Likert satisfaction scores (3.5 versus 4.5, P < 0.01). This study demonstrated a 17.2% reoperation incidence following MUA. Decreased ROM at two weeks, age, and CR implants were associated with additional intervention. These findings underscore the importance of early ROM recovery following MUA and the need for better understanding the biologic aspects of arthrofibrosis.