Drachmann Choi (watchrobert1)

The primary objective of this study was to evaluate the in vivo safety of a unicompartmental knee arthroplasty design with sequentially annealed cross-linked polyethylene by evaluating reoperation rate, in particular those related to excessive polyethylene wear or breakage. The secondary objective was to examine functional outcomes via standardized questionnaires. This was a 5-year institutional review board-approved prospective single-surgeon case series of the first 152 consecutive patients with symptomatic medial unicompartmental osteoarthritis implanted with a partial knee replacement between May 2010 and December 2014. Study participants were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthrtis Index (WOMAC) questionnaires at preoperation and 2 to 5 years postoperation. Major complications and all reoperations were recorded and we produced Kaplan-Meier survivorship curves with the end point of revision to TKA. Pre- and postoperative differences for KOOS and WOMAC were evaluated by paired t-tests. The median length of follow-up was 7.2 (0-9.72) years. Seven patients required revision surgery to TKA (4.9% of patients) four with progression of arthritis in other compartments, two for infection, and one for loosening of the femoral component and subsequent progression of pain. There were no failures of polyethylene. Survival of cohort was 99.3 and 97.9% at 2 and 5 years, respectively. Patients significantly improved (p-value less then 0.001) between preoperative assessment and at 2 years, with no decline at 5 years postoperation. These preliminary midterm results with this fixed-bearing design and cross-linked polyethylene were encouraging with no catastrophic failures of polyethylene. Patient reported outcomes were significantly improved and revision rates were acceptable and lower than registry reported results.The Journey-I total knee replacement was designed to improve knee kinematics but had several complications including early dislocation. The Journey-II modification was introduced to reduce these while maintaining high function. To assess whether the modified Journey-II prosthesis has succeeded in its designers aims, we undertook an observational study of prospectively recorded data to analyze and compare the two knees. A total of 217 Journey-I and 129 Journey-II knees were identified from the department's prospectively collated registry and were assessed at 1 year by a comparative statistical analysis using numerous factors including pain, functional activity, physical assessment, Short Form-12 (SF-12), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and Oxford scores. The statistical tests included Chi-square, Wilcoxon's rank and Mann-Whitney U-tests with the level of significance set at p less then 0.05. There was a variation in primary patella resurfacing between the two groups with 14.3% in the Journey-I cohort and 66.7% in the Journey-II cohort. Both replacements demonstrated excellent postoperative function, but the Journey II performed significantly better than Journey I with fewer complications (37 vs. 10) and better improvement in almost all clinical scores including pain (p less then 0.01), mobility outcomes (p = 0.018), Oxford (p = 0.004), and WOMAC (p = 0.039) scores but not with flexion improvement and SF-12 score. There was significant improvement in patellofemoral pain postoperatively in both the Journey I (p = 0.011) and Journey II (p = 0.042) arthroplasty; however the primarily resurfaced patella in a Journey-II implant had better postoperative scores. The main complication of dislocation in the Journey I was not seen in the modified Journey-II implant with stiffness requiring intervention reduced in Journey II. These results suggest that the Journey II has improved short-term clinical outcomes compared with Journey I with reduction