2015 ISAKOS Biennial Congress ePoster #1439
Does Prior Cartilage Restoration Negatively Impact Outcomes of Knee Arthroplasty?
Rachel M. Frank, MD, Aurora, CO UNITED STATES
Darren Plummer, BS, Chicago, IL UNITED STATES
Peter Chalmers, MD, Chicago, IL UNITED STATES
Brian J. Cole, MD, MBA, Chicago, IL UNITED STATES
Craig J. Della Valle, MD, Chicago, IL UNITED STATES
Rush University Medical Center, Chicago, IL, USA
FDA Status Not Applicable
Summary: Patients with a prior failed cartilage restoration procedure benefit less from knee arthroplasty compared to age, gender, BMI, smoking status, and worker's compensation status matched controls.
Cartilage restoration procedures are being performed with increasing frequency and if these procedures fail, patients may require unicompartmental (UKA) or total knee arthroplasty (TKA) to alleviate their symptoms. The purpose of this study was to compare patients who failed a cartilage restoration procedure to matched-controls undergoing primary knee arthroplasty. We hypothesized that patients undergoing cartilage restoration would have worse outcomes post-arthroplasty compared to patients without prior cartilage restoration.
We identified 13 patients who underwent cartilage restoration by a single surgeon and subsequently progressed to arthroplasty. Patients were matched to primary UKA/TKA controls based on gender, age ± 5 years, body mass index (BMI) ± 5, smoking status, and arthroplasty type and were followed for a minimum of 2-years (mean, 3.7; range, 2.0-7.2). The primary outcome was the Knee Society Score (KSS). Secondary outcomes were range of motion (ROM) and revision rate. Appropriate statistical analysis was performed for continuous data with between and within group comparisons.
A total of 26 patients (13 per group: 8 TKAs, 5 UKAs) were included. There were no significant differences in age, gender, BMI, smoking status, worker's compensation status, pre-op ROM, post-op ROM, or pre-operative KSS scores between groups (P>0.05 in all cases), suggesting adequate matching. Patients in the cartilage group had significantly lower pre-arthroplasty Kellgren and Lawrence grades (2.6±0.9) compared to controls (3.7±0.5, P=0.004). Patients in the cartilage group had significantly lower post-operative KSS scores (82±9 vs. 93±3, P=0.005) and experienced significantly less improvement in KSS scores (32±9 vs. 48±11, P<0.001). Two patients (15%) in the cartilage group required revision TKA at 1.9 years (for pain) and 4.7 years (for infection) following the index TKA.
While patients who fail to respond to cartilage restoration derive benefit from knee arthroplasty, the magnitude of improvement and final scores are lower than matched controls. Patients who failed cartilage restoration experienced lower than expected improvements following all treatment efforts (cartilage restoration and arthroplasty) suggesting that this cohort may represent a unique patient population. This information can be used to counsel this difficult patient population on expected outcomes following arthroplasty procedures.