CLINICAL AND FUNCTIONAL ASSESSMENT FOLLOWING AUTOLOGOUS CHONDROCYTE IMPLANTATION TO THE KNEE: THE ROLE OF PATIENT REPORTED OUTCOMES, PERFORMANCE BASED ASSESSMENT, AND RESPONSE SHIFT

Autologous chondrocyte implantation (ACI) is a cell based therapy for the treatment of articular cartilage defects. Numerous studies have reported outcomes following ACI using a variety of patient reported outcomes (PROs), but no clear recommendations exist regarding which PRO is the most responsive to changes following ACI. Few studies have documented changes in performance based assessments (PBAs) following ACI. Response shift theory proposes that residual changes in self-report measures occur over time. Failing to account for response shift may result in over or under reporting of outcomes from which clinical decisions are made. The purposes of this dissertation were 1) review the literature concerning ACI outcomes to determine the responsiveness of PROs to changes in self-reported function following ACI, 2) evaluate the reliability of PBAs among ACI patients, 3) develop a descriptive timeline for the return of function 1 year following ACI using both PROs and PBAs, and 4) utilize PROs and PBAs to evaluate patients undergoing ACI for evidence of response shift. All PRO and PBA measures were collected preoperatively and 3, 6, and 12 months postoperatively. A retrospective then-test PRO evaluation of function prior to surgery was completed at 6 and 12 months. Response shift was calculated by subtracting the original pre-test score from the then-test score. A systematic review and meta-analyses of existing ACI outcome studies resulted in the recommendation of the International Knee Documentation Committee Subjective Knee Form (IKDC) and Lysholm Knee Scale as highly responsive PROs among ACI patients of varying activity levels. Despite significant increases in PRO scores as early as 6 months following ACI, improvement in PBAs at 12 months following ACI were limited to stride length, walking speed, and step-up force. Finally, no evidence of a group level effect for response shift was observed. These results support the validity of traditional pre-test/post-test research designs with no need to account for response shift when evaluating treatment effects of ACI on the group level. However, the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) did show evidence of a measurable response shift on a patient by patient basis

The Role of Rehabilitation Following Autologous Chondrocyte Implantation: A Retrospective Chart Review

PURPOSE/BACKGROUND: Clinical outcomes following autologous chondrocyte implantation (ACI) are influenced by multiple factors, including patient demographics, lesion characteristics, quality of the surgical repair, and post-operative rehabilitation. However, it is currently unknown what specific characteristics of rehabilitation have the greatest influence on clinical outcomes following ACI. The purpose of this study was to conduct a retrospective chart review of patients undergoing ACI with the intent to describe this patient population\u27s demographics, clinical outcomes, and rehabilitation practices. This study aimed to assess the consistency of the documentation process relative to post-operative rehabilitation in order to provide information and guide initiatives for improving the quality of rehabilitation practices following ACI. METHODS: The medical records of patients treated for chondral defect(s) of the knee who subsequently underwent the ACI procedure were retrospectively reviewed. A systematic review of medical, surgical, and rehabilitation records was performed. In addition, patient-reported outcome measures (IKDC, WOMAC, Lysholm, SF-36) recorded pre-operatively, and 3, 6, and 12 months post-operatively were extracted from an existing database. RESULTS: 20 medical charts (35.9 ± 6.8 years; 9 male, 11 female) were systematically reviewed. The average IKDC, WOMAC, Lysholm, and SF-36 scores all improved from baseline to 3, 6 and 12 months post-operatively, with the greatest changes occurring at 6 and 12 months. There was inconsistent documentation relative to post-operative rehabilitation, including CPM use, weight-bearing progression, home-exercise compliance, and strength progressions. CONCLUSIONS: Due to variations in the documentation process, the authors were unable to determine what specific components of rehabilitation influence the recovery process. In order to further understand how rehabilitation practices influence outcomes following ACI, specific components of the rehabilitation process must be consistently and systematically documented over time. LEVEL OF EVIDENCE: 2C