Stiffness After Total Knee Arthroplasty: Prevalence and Treatment Outcome

Introduction Stiffness following total knee arthroplasty (TKA) is an incapacitating complication. The prevalence and causes leading to stiffness are not clearly determined. The aim of the study was to ascertain the prevalence, determine the influencing factors, and evaluate the efficacy of manipulation under anaesthesia (MUA) as a treatment option. Method Retrospective review of consecutive series of 1350 primary TKA over a 28-month period. For the purpose of the study, stiffness was defined as flexion contracture of >15 degrees and/or flexion of <75 degrees. Demographic data included co-morbidities, previous knee surgery, pre-operative and post-operative range of movement, anaesthetic techniques and use of nerve blocks, type of prosthesis, ligament balancing including release, mobility post-surgery, patient motivation, physiotherapy, complications, and final range of motion post-MUA. Results Of the 1350 patients evaluated, 33 (2.44%) had stiffness defined by the above-outlined criteria and required intervention. Thirty-one patients (2.29%) underwent MUA as a first-line treatment. No complications arose following MUA. One patient (0.07%) required arthroscopic arthrolysis while another patient (0.07%) required revision arthroplasty due to patellar mal-tracking. Following manipulation, mean flexion contracture decreased from 8 degrees to 3.6 degrees, and mean flexion improved from 51.8 degrees to 93.2 degrees. Arc of motion improved in 100% of patients but it is important to note that multiple manipulations were performed in seven patients. Conclusion Stiffness after TKA can be difficult to treat and can result in prolonged morbidity and dissatisfaction. This retrospective study highlights the effectiveness of manipulation under anaesthesia as a first-line treatment option leading to improved outcomes especially if done early.