Atul F. Kamath

Hip Arthroscopy for Labral Tears: Review of Clinical Outcomes With 4.8-Year Mean Follow-Up

Background Arthroscopy of the hip joint is a relatively new diagnostic and therapeutic option for labral tears. Purpose More data are needed to characterize the utility and effectiveness of hip arthroscopy and identify patient-related factors that might predict functional outcome. Study Design Case series; Level of evidence, 4. Methods This retrospective study with prospective follow-up examined the clinical outcomes of 52 consecutive patients undergoing hip arthroscopy for labral tears. Outcomes measures included clinical outcome and the modified Harris hip score. Any complications associated with the procedure were recorded. Exclusion criteria included age younger than 18 years or prior ipsilateral hip surgery. Results Mean patient age was 42 years. Mean follow-up was 4.8 years. Twenty-one patients (40.4%) had a traumatic cause of the labral tears. Eight patients (15.4%) had possible secondary gain issues. Four (7.7%) patients suffered transient nerve palsies; in 1 case, the guide wire broke during initial cannulation. Three patients (5.8%) went on to total hip arthroplasty after hip arthroscopy. On multivariate analysis, left-sided surgery, a higher preoperative activity level, and duration of symptoms greater than 18 months were found to be positive predictors of good or excellent outcomes. Smoking and secondary gain issues were significant negative predictors of good or excellent outcomes. Only prior level of activity was a significant positive predictor of return to activity after surgery. A traumatic cause of the labral tear was a significant negative predictor of return to activity. Chondromalacia and osteoarthritis were not significant predictors of negative outcome. Postoperative modified Harris hip score improved 40% from 56.8 preoperatively to 80.4 (P < .001). No cases of patients with secondary gain issues achieved good or excellent outcomes. Overall percentage of good or excellent outcomes was 56%, or 66% when those with secondary gain issues were excluded; 84% of patients were able to return to sports or equivalent level of preoperative recreational activity. Neither preoperative radiographic osteoarthritis nor grade of intraoperative chondromalacia predicted postoperative outcome. Conclusion This series supports the hypothesis that hip arthroscopy provides safe and reliable improvement of labral symptoms in the majority of patients.

Quantifying the Burden of Revision Total Joint Arthroplasty for Periprosthetic Infection

Periprosthetic joint infection (PJI) represents substantial clinical and economic burdens. This study evaluated patient and procedure characteristics and resource utilization associated with revision arthroplasty for PJI. The Nationwide Inpatient Sample (Q4 2005-2010) was analyzed for 235,857 revision THA (RTHA) and 301,718 revision TKA (RTKA) procedures. PJI was the most common indication for RTKA, and the third most common reason for RTHA. PJI was most commonly associated with major severity of illness (SOI) in RTHA, and with moderate SOI in RTKA. RTHA and RTKA for PJI had the longest length of stay. Costs were higher for RTHA/RTKA for PJI than for any other diagnosis except periprosthetic fracture. Epidemiologic differences exist in the rank, severity and populations for RTHA and RTKA for PJI.

Porous tantalum metaphyseal cones for severe tibial bone loss in revision knee arthroplasty: A five to nine-year follow-up

BACKGROUND Severe metaphyseal and meta-diaphyseal bone loss poses important challenges in revision total knee arthroplasty. The best strategy for addressing massive tibial bone loss has not been determined. The purpose of this study was to assess the intermediate-term clinical and radiographic results of porous tibial cone implantation. METHODS Sixty-six porous tantalum tibial cones (sixty-three patients) were reviewed at a mean follow-up time of seventy months (range, sixty to 106 months). According to the Anderson Orthopaedic Research Institute bone defect classification, twenty-four knees had a Type-3 defect, twenty-five knees had a Type-2B defect, and seventeen knees had a Type-2A defect. RESULTS The mean age at the time of the index revision was sixty-seven years (range, forty-one to eighty-three years), and 57% of patients were female. The mean American Society of Anesthesiologists Physical Status was 2.4 (range, 2 to 3), and the mean body mass index was 33 kg/m(2) (range, 25 to 53 kg/m(2)). Fifteen patients (24%) were on immunosuppressant medications, and eight patients (13%) were current smokers. The patients underwent a mean number of 3.4 prior knee surgical procedures (range, one to twenty procedures), and 49% of patients (thirty-one patients) had a history of periprosthetic infection. The mean Knee Society Scores improved significantly from 55 points preoperatively (range, 4 to 97 points) to 80 points (range, 28 to 100 points) at the time of the latest follow-up (p < 0.0001). One patient had progressive radiolucencies about the tibial stem and cone on radiographs. One patient had complete radiolucencies about the tibial cone, concerning for fibrous ingrowth. Three other cones were revised: one for infection, one for aseptic loosening, and one for periprosthetic fracture. Revision-free survival of the tibial cone component was >95% at the time of the latest follow-up. CONCLUSIONS Porous tantalum tibial cones offer a promising management option for severe tibial bone loss. At the intermediate-term follow-up (five to nine years), porous tantalum tibial cones had durable clinical results and radiographic fixation. The biologic ingrowth of these implants offers the potential for successful long-term structural support in complex knee reconstruction.

Early Effects of Resident Work-Hour Restrictions on Patient Safety: A Systematic Review and Plea for Improved Studies

BACKGROUND since the inception of the eighty-hour work week, work hour restrictions have incited considerable debate. Work hour policies were designed to prevent medical errors and to reduce patient morbidity and mortality. It is unclear whether work hour restrictions have been helpful in medicine in general and in orthopaedic surgery specifically. This systematic review of the literature was designed to determine the success of these restrictions in terms of patient mortality, medical errors, and complications. METHODS a systematic review of the literature was performed to determine if work hour rules have improved patient and systems-based outcomes and reduced physician errors as measured by mortality, medical errors, and complications. A random effects model was utilized to determine whether patient mortality rates were improved under the new rules. RESULTS the odds of patient death before implementation of the work hour rules were 1.12 (95% confidence interval, 1.07 to 1.17) times those after implementation. These differences were consistent across disciplines. The data concerning medical or surgical complications before and after the institution of the work hour rules were mixed. There was little information in these studies concerning direct medical errors. The odds of death in nonteaching cohorts were not significantly different from that in teaching cohorts. CONCLUSIONS there appears to be a decrease in mortality following the institution of work hour rules. The difference seen in teaching cohorts is not significantly different from that in nonteaching cohorts. It is unclear whether this difference would have been observed even without work hour restrictions. No study has shown a reduction in mortality for orthopaedic patients in teaching cohorts that was greater than that observed in nonteaching cohorts. Because of methodological concerns and the lack of current literature linking physician fatigue and physician underperformance with patient mortality, it is unclear whether the goals of the work hour reductions have been achieved. Furthermore, because of a lack of a so-called dose-response relationship between work hour reduction and patient mortality, it is uncertain whether further reductions would be beneficial. LEVEL OF EVIDENCE therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Prospective Results of Uncemented Tantalum Monoblock Tibia in Total Knee Arthroplasty Minimum 5-Year Follow-up in Patients Younger Than 55 Years

A significant increase in younger patients undergoing total knee arthroplasty raises the theoretical concern for revision secondary to micromotion and fixation failure with cemented components. We prospectively studied 100 consecutive tantalum monoblock uncemented tibial components and 312 concurrent cemented controls. Patients younger than 55 years with adequate bone stock were enrolled. This cementless patient group was younger and had higher preoperative functional status. Prostheses were posterior-substituting uncemented femoral and tibial components with a cemented patellar button. Knee Society pain and function scores and radiographs were obtained, and a cost analysis was performed. Knee Society scores were excellent and equivalent beyond 6 months. There was no significant difference in perioperative blood loss, complication rates, or cost. There was a significant decrease in operative time in the uncemented group. Radiographs revealed no failures of ingrowth at last follow-up. There were 3 uncemented group failures, but none were due to failure of fixation. The use of a porous tantalum tibia at minimum 5 years has yielded promising clinical and radiographic results in a younger patient population.

Effect of Body Mass Index on Complications and Reoperations After Total Hip Arthroplasty

BACKGROUND High body mass index (BMI) is associated with increased rates of complications after total hip arthroplasty. Studies to date have evaluated risk mainly as a dichotomous variable according to BMI thresholds. The purpose of this paper was to characterize the risk of complications and implant survival according to BMI as a continuous variable. METHODS Using prospectively collected data from our institutional total joint registry, we analyzed 21,361 consecutive hips (17,774 patients) treated with primary total hip arthroplasty between 1985 and 2012 at a single institution. The average BMI at the time of surgery was 28.7 kg/m(2) (range, 15 to 69 kg/m(2)). Estimates of revision surgery and common complications associated with BMI were analyzed using the Kaplan-Meier method of assessing survivorship, with associations of outcomes assessed using a Cox model. RESULTS Utilizing smoothing spline parameterization, we found that reoperation (p < 0.001) and implant revision or removal rates (p = 0.002) increased with increasing BMI. Increasing BMI was associated with increased rates of early hip dislocation (p = 0.02), wound infection, and, most strikingly, deep periprosthetic infection (a hazard ratio of 1.09 per unit of BMI >25 kg/m(2); p < 0.001). However, we found no association between increasing BMI and any revision for mechanical failure of the implant or between increasing BMI and revision for aseptic implant loosening. There was an inverse correlation between increasing BMI and risk of revision for bearing wear. CONCLUSIONS The rates of reoperation, implant revision or removal, and common complications after total hip arthroplasty were strongly associated with BMI.

Modern Total Hip Arthroplasty in Patients Younger Than 21 Years

Total hip arthroplasty (THA) is not commonly performed in adolescents. However, it may be the only option for pain control with continued mobility for advanced disease. We report our experience with modern alternative-bearing THA in patients younger than 21 years. Twenty-one THAs (18 patients) were followed. Preoperative and postoperative Harris hip scores were recorded, and radiographs were reviewed. Average follow-up was 49 months (range, 25-89). Underlying etiology was chemotherapy-induced osteonecrosis (33%), steroid-induced osteonecrosis (29%), sickle cell disease (24%), and chronic dislocation (14%). Articulation bearings were ceramic/ceramic (67%), metal/highly cross-linked polyethylene (29%), and metal resurfacing (5%). Mean age was 18 years (range, 13-20). Harris hip scores improved from 43.6 to 83.6 (P < .001). At final follow-up, there was no radiographic loosening; 1 THA was revised for a cracked ceramic liner. At intermediate-term follow-up, clinical and radiographic results are favorable after alternative-bearing THA in patients younger than 21 years.

Bundled Payment in Total Joint Care: Survey of AAHKS Membership Attitudes and Experience with Alternative Payment Models

The goal of alternative payment models (APMs), particularly bundling of payments in total joint arthroplasty (TJA), is to incentivize physicians, hospitals, and payers to deliver quality care at lower cost. To study the effect of APMs on the field of adult reconstruction, we conducted a survey of AAHKS members using an electronic questionnaire format. Of the respondents, 61% are planning to or participate in an APM. 45% of respondents feel that a bundled payment system will be the most effective model to improve quality and to reduce costs. Common concerns were disincentives to operate on high-risk patients (94%) and uncertainty about revenue sharing (79%). While many members feel that APMs may improve value in TJA, surgeons continue to have reservations about implementation.

Unplanned Admission to the Intensive Care Unit After Total Hip Arthroplasty

Triage to the intensive care unit (ICU) after elective total hip arthroplasty proves a complex medical and resource decision point. A total of 1259 consecutive total hip arthroplasties were reviewed; 89 patients experienced unplanned ICU admissions. Significant risk factors for ICU admission in univariate analysis were age greater than 75 years, revision surgery, obstructive sleep apnea, creatinine clearance less than 60 mL/min, prior myocardial infarction, American Society of Anesthesiologist class 3 or greater, use of vasopressors intraoperatively, and body mass index greater than 35 kg/m(2). With multiple regression, age greater than 75 years (odds ratio [OR], 2.6 [1.2-5.6]), revision surgery (OR, 5.8 [3.0-11.4]), creatinine clearance less than 60 mL/min (OR, 6.5 [2.5-16.3]), prior myocardial infarction (OR, 7.2 [2.0-25.4]), and body mass index greater than 35 kg/m(2) (OR, 2.9 [1.4-6.2]) were predictive of unplanned ICU admission. With 1 risk factor, the risk of ICU admission was 40%, 2 (75%), 3 (93.5%), 4 (98.5%), and 5 (>99%). A prospective study of these risk factors is needed to establish a threshold for planned ICU admission.

Hypoalbuminemia More Than Morbid Obesity is an Independent Predictor of Complications After Total Hip Arthroplasty

Health care reform is directing clinical practice towards improving outcomes and minimizing complications. Preoperative identification of high-risk patients and modifiable risk factors present opportunity for clinical research. A total of 49,475 total hip arthroplasty patients were identified from National Surgical Quality Improvement Program between 2006 and 2013. We compared morbidly obese patients (BMI≥40 kg/m(2)) and non-morbidly obese patients (BMI 18.5-40 kg/m(2)). We also compared patients with hypoalbuminemia (serum albumin <3.5 g/dL) against those with normal albumin. Our study demonstrates that hypoalbuminemia is a significant risk factor for mortality and major morbidity among total hip arthroplasty patients, while morbid obesity was only associated with an increased risk of superficial surgical site infection. Impressively, hypoalbuminemia patients carried a 5.94-fold risk of 30-day mortality.