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.

Retreatment after percutaneous nephrolithotomy in the computed tomographic era: long-term follow-up.

OBJECTIVE: To examine the long-term retreatment rates and explore prognostic factors after percutaneous nephrolithotomy (PCNL) in the computed tomographic era. METHODS: Consecutive patients who underwent PCNL with a standardized technique attempting complete fragment detection and clearance by a single surgeon between September 2000 and June 2004 were identified. Through medical record, review details of procedures and outcomes were collected. RESULTS: A total of 166 renal units in 150 subjects were evaluated. Postoperative computed tomographic scans were conducted in 129 subjects. Median follow-up was 5.4 years (interquartile range, 4.2-6.2 years). Future ipsilateral procedures were performed in 23 renal units (14%) at a median of 2.9 years (interquartile range, 1.7-3.7 years). The cumulative retreatment rate at 7 years for noncalcium stones (24%) was not significantly higher than for calcium-based stones (14%; P = .07). Stone-free renal units had a lower cumulative retreatment rate (4%) than those with residual fragments <2 mm (33%) or ≥2 mm (30%; P = .001). When controlling for residual fragment size, renal units that were composed of uric acid or struvite had an expected hazard rate of retreatment 3.34 times larger than renal units composed of calcium oxalate/phosphate (P = .02) and renal units that were not stone free had an expected hazard rate 7.87 times larger than renal units that were stone free (P = .001). CONCLUSION: In this population of complex stone patients treated by PCNL, there appears to be no such thing as an "insignificant fragment." Efforts at initial stone clearance should be maximized.

Efficacy of revision surgery for the dislocating total hip arthroplasty: report from a large community registry.

BACKGROUND: Historically, achieving stability for the unstable total hip arthroplasty (THA) with revision surgery has been achieved inconsistently. Most of what we know about this topic comes from reports of high-volume surgeons' results; the degree to which these results are achieved in the community is largely unknown, but insofar as most joint replacements are done by community surgeons, the issue is important. QUESTIONS/PURPOSES: We used a community joint registry to determine: (1) the frequency of repeat revision after surgery to treat the unstable THA; (2) what surgical approaches to this problem are in common use in the community now; (3) are there differences in repeat revision frequency that vary by approach used; and (4) has the frequency of repeat revision decreased over time as surgical technique and implant options have evolved? METHODS: We reviewed 6801 primary THAs performed in our community joint registry over the last 20 years. One hundred eighteen patients (1.7%) with a mean age of 67 years were revised within the registry for instability/dislocation. Failure was defined as a return to the operating room for rerevision surgery for instability. Minimum followup was 2 years (average, 9.4 years; range, 2-20 years) with six patients having incomplete followup. The frequency of rerevisions was calculated and compared using Pearson's chi-square test. Cumulative rerevision rates were calculated using the Kaplan-Meier method and types of revision procedures were compared using the log-rank test. RESULTS: The initial revision procedure was successful in 108 patients (92%); 10 patients underwent repeat surgery for recurrent dislocation after their initial revision surgery. The most frequently performed procedure was revision of the head and liner only (35 of 118 [30%]); constrained devices were used in 19% (22 of 118) of the procedures. There was no difference in the cumulative rerevision rates for instability or dislocation by type of revision procedure performed. Six of 22 constrained liners were rerevised for varying indications. There was no difference in frequency of repeat revision for instability between those patients revised for THAs performed before 2003 and those managed more recently. CONCLUSIONS: Revision surgery for unstable THA is successfully managed in the community with a variety of surgical interventions. Identifying the reason for dislocation and addressing the source remain paramount. Constrained liners should be used with caution; although typically used in the most problematic settings, rerevision for a variety of failure modes remains troublesome. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Improved survival of uncemented versus cemented femoral stems in patients aged < 70 years in a community total joint registry.

BACKGROUND: Aseptic loosening of the femoral stem remains a significant reason for revision in total hip arthroplasty (THA). Although stem fixation methods have changed over time, there is relatively little evidence supporting cemented or uncemented stems as more durable constructs. QUESTIONS/PURPOSES: We examined whether there was a difference in survival to revision between cemented and uncemented THA stems (1) for any reason; (2) for aseptic loosening or loosening related to wear/osteolysis; (3) based on patient age groupings (as a proxy for patient activity level); and (4) based on procedural timeframe groupings between cemented and uncemented stems. METHODS: A total of 6498 primary cemented and uncemented THAs were registered in our community total joint replacement registry between 1991 and 2011. Analysis was performed to compare age, sex, procedural timeframe, and diagnosis for both groups. Our primary outcome was revision of the stem component for aseptic loosening or loosening secondary to wear/osteolysis. Analyses were done using Wilcoxon rank sum tests, Pearson's chi-square tests, Kaplan Meier methods, and Cox regression. RESULTS: After adjusting for age, sex, primary diagnosis, and procedural timeframe as confounders, cemented femoral stem components were 1.63 times as likely as uncemented stems to be revised for any reason (p = 0.02) and 3.76 times as likely as uncemented stems to be revised for aseptic loosening or loosening related to wear/osteolysis (p < 0.001). When grouped by age, specifically in regard to revisions for aseptic loosening or loosening related to wear/osteolysis, uncemented stems had lower cumulative revision rates in patients aged < 70 years (p < 0.001) compared with cemented stems. There was a trend away from cemented fixation in our registry, which shifted from over 80% cemented stem use in 1996 to 3% in 2011. CONCLUSIONS: We found that uncemented stems were associated with fewer revisions for aseptic loosening in patients < 70 years old, but when all reasons for revision were considered, neither group demonstrated superior survival. With a mean followup of 6.5 years, longer followup is needed to verify these results over time.

Aggregate Interview Method of ranking orthopedic applicants predicts future performance.

This article evaluates and describes a process of ranking orthopedic applicants using what the authors term the Aggregate Interview Method. The authors hypothesized that higher-ranking applicants using this method at their institution would perform better than those ranked lower using multiple measures of resident performance. A retrospective review of 115 orthopedic residents was performed at the authors' institution. Residents were grouped into 3 categories by matching rank numbers: 1-5, 6-14, and 15 or higher. Each rank group was compared with resident performance as measured by faculty evaluations, the Orthopaedic In-Training Examination (OITE), and American Board of Orthopaedic Surgery (ABOS) test results. Residents ranked 1-5 scored significantly better on patient care, behavior, and overall competence by faculty evaluation (P<.05). Residents ranked 1-5 scored higher on the OITE compared with those ranked 6-14 during postgraduate years 2 and 3 (P⩽.5). Graduates who had been ranked 1-5 had a 100% pass rate on the ABOS part 1 examination on the first attempt. The most favorably ranked residents performed at or above the level of other residents in the program; they did not score inferiorly on any measure. These results support the authors' method of ranking residents. The rigorous Aggregate Interview Method for ranking applicants consistently identified orthopedic resident candidates who scored highly on the Accreditation Council for Graduate Medical Education resident core competencies as measured by faculty evaluations, performed above the national average on the OITE, and passed the ABOS part 1 examination at rates exceeding the national average.

Cumulative revision rate is higher in metal-on-metal THA than metal-on-polyethylene THA: analysis of survival in a community registry.

BACKGROUND: Metal-on-metal (MOM) THA bearing technology has focused on improving the arc of motion and stability and minimizing wear compared with traditional metal-on-polyethylene (MOP) bearing couples. It is unclear whether this more costly technology adds value in terms of improved implant survival. QUESTIONS/PURPOSES: This study evaluated Kaplan-Meier survival, revisions for dislocation, and cost of MOM THA compared with metal-on-cross-linked polyethylene (MOXP) THA in a community joint registry, with subset analysis of the recalled Depuy ASR™ implant. METHODS: All MOM THAs (resurfacings excluded) performed between January 2002 and December 2009 were included (n = 1118) and compared with a control group of MOXP THAs (n = 1286) done during the same time. Analysis was performed to compare age, gender, cost of implant, length of stay, year of index procedure, diagnosis, head size (< 32 mm versus ≥ 32 mm), revision and revision reason for both groups. Analysis at a mean of 3.6 years was done using Wilcoxon rank sum tests, Pearson's chi-square tests, Kaplan Meier methods, and Cox regression. RESULTS: The cumulative revision rate (CRR) was higher in MOM implants than in MOXP implants (MOM CRR = 13%; MOXP CRR = 3%). MOM implants were three times as likely to be revised as MOXP implants after adjustment for age, head size, and year of procedure. The recalled DePuy ASR™ implant was six times as likely to be revised as other MOM THAs. After removing the ASR™ implants from analysis, survivorship of MOM implants was not better than that of the MOXP hips. CONCLUSIONS: During the study time, MOM THAs showed inferior survival to MOXP THAs after adjusting for age, head size, and year of procedure. Longer followup is necessary to see whether MOM THAs add value in younger patient groups.

Midterm outcomes in patients with cam femoroacetabular impingement treated arthroscopically.

PURPOSE: The purpose of this study was to evaluate the midterm outcomes of patients with cam-type femoroacetabular impingement treated arthroscopically. METHODS: Outcomes were measured with the Nonarthritic Hip Score (NAHS), visual analog scale pain scores, and satisfaction levels preoperatively; at 6 weeks and 3, 6, 12, and 24 months postoperatively; and at final follow-up. Two hundred one procedures were available for final assessment with a minimum follow-up of 36 months (mean, 46 months). Ninety-nine percent of hips had a preoperative Tönnis grade of 1 or less. RESULTS: The NAHS significantly improved from a mean of 56.1 to 78.2 (P < .001). Visual analog scale pain scores improved from a mean of 6.8 to 2.7 (P < .001). Preoperative to postoperative satisfaction levels improved from 0.5% to 75% of procedures. Twelve patients required hip arthroplasty during the follow-up period and had a higher incidence of grade 4 acetabular chondral defects versus those without arthroplasty (P < .03). Patients with pincer resections had significantly poorer results versus the remainder of the cohort (P < .01). CONCLUSIONS: We have shown satisfactory results using a validated hip scoring system, showing improvement in NAHS, pain scores, and satisfaction levels in a large cohort of patients with cam-type femoroacetabular impingement followed up for a mean of 46 months. The results have shown improvement and stability throughout a range of 36 to 70 months' follow-up. There was no difference in preoperative to postoperative NAHS between age groups. There was a larger percentage of grade 4 acetabular chondral defects in those patients who needed conversion to hip arthroplasty. Patients with associated pincer pathology had poorer results after acetabular rim resection. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

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.

Emergency surgical salvage for severe intracranial aneurysm rupture during endovascular coiling procedures not amenable to additional coiling.

BACKGROUND: We report the management and outcomes of six patients who underwent emergency surgical intervention in the setting of severe intraprocedural rupture during endovascular treatment of an intracranial aneurysm not amenable to additional coiling. METHODS: From July 1997 through December 2010, our neurovascular service treated 1613 patients with coil embolization. During this time, we encountered six patients who suffered severe intraprocedural aneurysm rupture, defined by contrast extravasation during the coiling procedure, in whom additional attempted coiling failed to stop the ongoing extravasation. Hospital records, neuroimaging studies, operative reports, and follow-up clinic notes were complete and reviewed in all cases. The follow-up review in surviving patients ranged from 1.5 to 9 years (average 3.8 years), and no patient was lost to the follow-up review. RESULTS: In all cases, persistent extravasation necessitated urgent surgical decompression and securing of the ruptured aneurysm. Of these six cases, three patients achieved a good functional status after prolonged rehabilitation, and one of these had only subtle cognitive changes on formal neuropsychological testing. Two patients died. CONCLUSION: Intraprocedural rupture during aneurysm coiling is a dangerous and potentially fatal event. Despite the seemingly hopeless nature of this situation, in our experience, aggressive management to control intracranial pressure combined with a rapid reversal of anticoagulation and early surgical intervention can result in reasonable outcomes in some patients.

Do "premium" joint implants add value?: analysis of high cost joint implants in a community registry.

BACKGROUND: Numerous joint implant options of varying cost are available to the surgeon, but it is unclear whether more costly implants add value in terms of function or longevity. QUESTIONS/PURPOSES: We evaluated registry survival of higher-cost "premium" knee and hip components compared to lower-priced standard components. METHODS: Premium TKA components were defined as mobile-bearing designs, high-flexion designs, oxidized-zirconium designs, those including moderately crosslinked polyethylene inserts, or some combination. Premium THAs included ceramic-on-ceramic, metal-on-metal, and ceramic-on-highly crosslinked polyethylene designs. We compared 3462 standard TKAs to 2806 premium TKAs and 868 standard THAs to 1311 premium THAs using standard statistical methods. RESULTS: The cost of the premium implants was on average approximately $1000 higher than the standard implants. There was no difference in the cumulative revision rate at 7-8 years between premium and standard TKAs or THAs. CONCLUSIONS: In this time frame, premium implants did not demonstrate better survival than standard implants. Revision indications for TKA did not differ, and infection and instability remained contributors. Longer followup is necessary to demonstrate whether premium implants add value in younger patient groups. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Can this prosthesis be saved?: implant salvage attempts in infected primary TKA.

BACKGROUND: Open débridement with polyethylene liner exchange (ODPE) remains a relatively low morbidity option in acute infection of total knee arthroplasty (TKA), but concerns regarding control of infection exist. We sought to identify factors that would predict control of infection after ODPE. METHODS: We identified 44 patients (44 knees) with culture-positive periprosthetic infection who underwent ODPE. Failure was defined as any reoperation performed for control of infection or the need for lifetime antibiotic suppression. Patients had been followed prospectively for a minimum of 1 year (mean, 5 years; range, 1-9 years). RESULTS: Twenty-five of the 44 patients (57%) failed ODPE. Of these 25 patients, two had one additional procedure, 21 had more than one additional procedure, and two required lifetime antibiotic suppression. Failure rates tended to differ based on primary organism: 71% of Staphylococcus aureus periprosthetic infection failed versus 29% of Staphylococcus epidermidis, although with the limited numbers theses differences were not significant. Age, gender, or measures of comorbidity did not influence the risk of failure. There was no difference in failure rate (58% versus 50%) when the ODPE was performed greater than 4 weeks after index TKA. After a failed ODPE, 19 of the 25 failures went on to an attempted two-stage revision procedure. In only 11 of these 19 cases was the two-stage revision ultimately successful. CONCLUSIONS: Eradication of infection with ODPE in acute TKA infections is unpredictable; certain factors trend toward increased success but no firm algorithm can be offered. The success of two-stage revision for infection may be diminished after a failed ODPE. LEVEL OF EVIDENCE: Level III, retrospective comparative study. See Guidelines for Authors for a complete description of levels of evidence.

High prevalence of gouty arthritis among the Hmong population in Minnesota.

OBJECTIVE: The prevalence of gout is on the rise worldwide, especially among newly industrialized populations. We evaluated the prevalence of gout in the recently established Hmong of Minneapolis/St. Paul (MSP) compared with that in non-Hmong populations. METHODS: The prevalence of self-reported gout in the Hmong population was estimated from 2 cross-sectional community surveys and compared with national data extrapolated from the Third National Health and Nutrition Examination Survey. The prevalence of physician-diagnosed gout in Hmong and non-Hmong MSP residents was separately estimated from the diagnosis codes of 11 MSP primary care clinics. RESULTS: The prevalence of self-reported gout among MSP Hmong was 2-fold higher than in the general US population (6.5% versus 2.9%; P < 0.001). Although women of both groups reported gout at a rate of 1.9%, Hmong men were significantly more likely than their non-Hmong counterparts to report gout (11.5% versus 4.1%; P < 0.001). Similar results were observed when investigating physician-diagnosed gout in MSP (2.8% Hmong versus 1.5% non-Hmong; P < 0.001). No difference was observed between the women of the 2 groups (0.8% versus 0.7%; P = 0.833), whereas Hmong men were more than twice as likely to be diagnosed with gout compared with their non-Hmong counterparts (6.1% versus 2.5%; P < 0.001). Among Hmong men, advancing age was associated with a considerably higher likelihood of being diagnosed with gout. CONCLUSION: A significant association is observed between Hmong ethnicity and gout, both self-reported and physician diagnosed. This unique population may provide an opportunity to further our understanding of the pathophysiology of gout.

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.