How often is the office visit needed? Predicting total knee arthroplasty revision risk using pain/function scores.

BACKGROUND: Most patients have favorable outcomes after primary total knee arthroplasty (TKA). Well-validated methods to predict the risk of poor outcomes have not been developed or implemented. Several patients have annual clinic visits despite well-funcitoning TKA, as a routine practice, to detect early failure requiring revision surgery. It is not known whether assessment of pain and function can be used as a predictive tool for early failure and revision to guide practice. Our objective was to determine whether pain and function can predict revision after TKA. METHODS: We retrospectively studied data from a large prospectively gathered TKA registry to examine changes in outcome scores for primary TKAs undergoing revision compared to those not requiring revision to determine the factors that are predictive for revision. RESULTS: Of the 1,012 patients, 721 had had a single-sided primary TKA and had American Knee Society (AKS) Scores for three or more visits. 46 patients underwent revision, 23 acutely (fracture, traumatic component failure or acute infection) and 23 for latent causes (late implant loosening, progressive osteolysis, or pain and indolent infection). Mean age was 70 years for the non-revision patients, and 64 years for those revised. Both AKS Clinical and AKS Function Scores for non-revised patients were higher than in revision patients, higher in acute revision compared to latent revision patients. Significant predictors of revision surgery were preoperative, 3- and 15-month postoperative AKS Clinical Scores and 3-month AKS Function Scores. At 15-month post-TKA, a patient with a low calculated probability of revision, 32 % or less, was unlikely to require revision surgery with a negative predictive value of 99 %. CONCLUSION: Time dependent interval evaluation post-TKA with the AKS outcome scores may provide the ability to assign risk of revision to patients at the 15-month follow-up visit. If these findings can be replicated using a patient-reported measure, a virtual follow-up with patient-reported outcomes and X-ray review may be an alternative to clinic visit for patients doing well.

Revision surgery for patellofemoral problems: should we always resurface?

BACKGROUND: Routine patellar resurfacing performed at the time of knee arthroplasty is controversial, with some evidence of utility in both TKA (tricompartmental) and bicompartmental knee arthroplasty. However, whether one approach results in better implant survival remains unclear. QUESTIONS/PURPOSES: We asked whether (1) routine patellar resurfacing in TKAs resulted in lower cumulative revision rates compared to bicompartmental knee arthroplasties, (2) patella-friendly implants resulted in lower cumulative revision rates than earlier designs, and (3) bicompartmental knee arthroplasties revised to TKAs had higher cumulative revision rates than primary TKAs. PATIENTS AND METHODS: From a community-based joint registry, we identified 8135 patients treated with 9530 cemented, all-polyethylene patella TKAs and 627 bicompartmental knee arthroplasties without patellar resurfacing. We compared age, gender, year of index procedure, diagnosis, cruciate status, revision, and revision reason. RESULTS: TKAs had a lower cumulative revision rate for patella-only revision than bicompartmental knee arthroplasties (0.8% versus 4.8%). Adjusting for age, bicompartmental knee arthroplasties were 6.9 times more likely to undergo patellar revision than TKAs. There was no difference in the cumulative revision rate for patella-only revisions between patella-friendly and earlier designs. The cumulative revision rate for any second revision after a patella-only revision was 12.7% for bicompartmental knee arthroplasties while that for primary TKAs was 6.3%. CONCLUSIONS: Bicompartmental knee arthroplasties had higher revision rates than TKAs. Femoral component design did not influence the cumulative revision rate. Secondary patella resurfacing in a bicompartmental knee arthroplasty carried an increased revision risk compared to resurfacing at the time of index TKA. To reduce the probability of reoperation for patellofemoral problems, our data suggest the patella should be resurfaced at the time of index surgery.

Do men outperform women during orthopaedic residency training?

BACKGROUND: Orthopaedic surgery residency has one of the lowest percentages of women (13.1%) of all primary surgical specialties. There are many possible reasons for this, including bias during the selection process. QUESTIONS/PURPOSES: We therefore asked whether performance during residency might adversely bias the selection of future female orthopaedic residents by researching whether males and females perform equally in orthopaedic surgery residency. METHODS: Ninety-seven residents enrolled in our residency between 1999 and 2009; six males and one female left the program, leaving 90 residents (73 males, 17 females) as the study cohort. Resident performance was compared for OITE scores, ABOS results, faculty evaluations, and in a resident graduate survey. RESULTS: Males and females had similar faculty evaluations in all ACGME competency areas. Males and females had similar mean OITE scores for Years 2-5 of residency, although males had higher mean scores at Years 3 through 5. Males and females had similar mean ABOS Part 1 scores and ABOS Part 1 pass rates; however, fewer males than females took more than one attempt to pass. Males and females had similar Part 2 pass rates or attempts. For the 45 resident graduates surveyed, females pursued fellowships equally to males, worked slightly less hours in practice, and reported higher satisfaction with their career choice. CONCLUSIONS: For the 90 residents at one residency program, we observed no differences between males' and females' performance. Although females pursue orthopaedic residency less frequently than males, performance during residency should not bias their future selection.

Do porous tantalum implants help preserve bone?: evaluation of tibial bone density surrounding tantalum tibial implants in TKA.

BACKGROUND: TKA with conventional metal-backed tibial implants subjects the tibial metaphysis to stress shielding, with resultant loss of bone density. QUESTIONS/PURPOSES: We hypothesized tibial bone mineral density in patients with porous tantalum (trabecular metal) tibial baseplates would (1) more closely parallel tibial bone mineral density in the nonoperative control limb and (2) be better maintained than in conventional historical controls. PATIENTS AND METHODS: We prospectively followed 41 patients (35 men, six women) 60 years of age or younger undergoing TKA with uncemented trabecular metal tibial components. Patients underwent dual-energy xray absorptiometry scans of both proximal tibiae preoperatively and at 2 months, 1 year, and 2 years postoperatively. We determined bone mineral density in three selected regions of interest (Zone 1, between the pegs; Zone 2, beneath the pegs; Zone 3, directly below entire baseplate). Precision analysis revealed a precision error of 4% or less for each region of interest, indicating adequate power to detect bone mineral density changes of 8% or greater. RESULTS: Bone mineral density percent change was different between the operative and nonoperative knees only in Zone 3 and only at 2 months. There was no change in bone mineral density in any zone in the nonoperative knee at any time. Only in Zone 3 did the bone mineral density decrease at 2 months in the operative knee. CONCLUSIONS: Trabecular metal implants appear to maintain tibial bone mineral density in a parallel fashion to the nonoperative limb in this population and better than historical controls.