Validating Orthopaedic Data Evaluation Panel (ODEP) Ratings Across 9 Orthopaedic Registries: Total Hip Implants with an ODEP Rating Perform Better Than Those without an ODEP Rating.

BACKGROUND: Orthopaedic Data Evaluation Panel (ODEP) ratings of total hip (TH) and total knee (TK) implants are informative for assessing implant performance. However, the validity of ODEP ratings across multiple registries is unknown. Therefore, we aimed to assess, across multiple registries, whether TH and TK implants with a higher ODEP rating (i.e., an A* rating) have lower cumulative revision risks (CRRs) than those with a lower ODEP rating (i.e., an A rating) and the extent to which A* and A-rated implants would be A*-rated on the basis of the pooled registries' CRR. METHODS: Implant-specific CRRs at 3, 5, and 10 years that were reported by registries were matched to ODEP ratings on the basis of the implant name. A meta-analysis with random-effects models was utilized for pooling the CRRs. ODEP benchmark criteria were utilized to classify these pooled CRRs. RESULTS: A total of 313 TH cups (54%), 356 TH stems (58%), 218 TH cup-stem combinations (34%), and 68 TK implants (13%) with unique brand names reported by registries were matched to an ODEP rating. Given the low percentage that matched, TK implants were not further analyzed. ODEP-matched TH implants had lower CRRs than TH implants without an ODEP rating at all follow-up time points, although the difference for TH stems was not significant at 5 years. No overall differences in CRRs were found between A* and A-rated TH implants, with the exception of TH cup-stem combinations, which demonstrated a significantly lower CRR for A*A*-rated cup-stem combinations at the 3-year time point. Thirty-nine percent of A*-rated cups and 42% of A*-rated stems would receive an A* rating on the basis of the pooled registries' CRR at 3 years; however, 24% of A-rated cups and 31% of A-rated stems would also receive an A* rating, with similar findings demonstrated at longer follow-up. CONCLUSIONS: At all follow-up time points, ODEP-matched TH implants had lower CRRs than TH implants without an ODEP rating. Given that the performance of TH implants varied across countries, registries should first validate ODEP ratings with use of country-specific revision data to better guide implant selection in their country. Data source transparency and the use of revision data from multiple registries would strengthen the ODEP benchmarks. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Camouflage uncovered: what should happen next?

Recent publications have drawn attention to the fact that some brands of joint replacement may contain variants which perform significantly worse (or better) than their 'siblings'. As a result, the National Joint Registry has performed much more detailed analysis on the larger families of knee arthroplasties in order to identify exactly where these differences may be present and may hitherto have remained hidden. The analysis of the Nexgen knee arthroplasty brand identified that some posterior-stabilized combinations have particularly high revision rates for aseptic loosening of the tibia, and consequently a medical device recall has been issued for the Nexgen 'option' tibial component which was implicated. More elaborate signal detection is required in order to identify such variation in results in a routine fashion if patients are to be protected from such variation in outcomes between closely related implant types.

Soft-tissue tension total knee arthroplasty.

It is far from clear how best to define the proper strength of soft-tissue tensioning in total knee arthroplasty (TKA). We attached a torque driver to the Monogram balancer/tensor device and measured soft-tissue tension in full extension and 90 degrees flexion during TKA. In our surgical procedure, when we felt proper soft-tissue tension was being applied, the mean distraction force was noted to be 126N in extension and 121N in flexion. There was no significant correlation between soft-tissue tension and the postoperative flexion angle finally achieved. To the best of our knowledge, this is the first study to assess the actual distraction forces in relation to soft-tissue tension in TKA. Further study may reveal the most appropriate forces to achieve proper soft-tissue tension in the wide variety of circumstances presenting at knee arthroplasty.