Faculty Bibliography

BACKGROUND: In this glenoid loosening study, we compared the fixation strength of multiple generic reverse shoulder glenoid baseplates that differed only in backside geometry and shape and size to optimize design from a fixation perspective. METHODS: The fixation strength of 4 generic baseplates was quantified in a low-density polyurethane substrate to isolate the contribution of baseplate profile and size (25 mm circular vs 25 x 34 mm oval) and backside geometry (flat back vs curved back) on fixation using 2 center-of-rotation glenospheres (0 mm and 10 mm lateral). The cyclic test simulated 55 degrees of abduction as a 750 N load was continuously applied to induce a variable shear and compressive load. Before and after cyclic loading, baseplate displacement was measured in the directions of the applied static shear and compressive loads. Each generic baseplate was cyclically tested 7 times with each offset glenosphere for a total of 56 samples. RESULTS: Circular baseplates were associated with significantly more shear displacement in both the superior-inferior (SI) and anterior-posterior (AP) directions after cyclic loading than oval baseplates. No such significant differences in fixation were observed between flat-back and curved-back baseplates. Circular baseplates were also associated with significantly more SI and AP shear displacement with 10 mm glenospheres than with 0 mm glenospheres. No significant difference in SI or AP motion was observed with oval baseplates between 0 mm and 10 mm glenospheres. DISCUSSION: Our results suggest that baseplate shape and size affects fixation strength more than backside geometry. The 25 x 34 mm oval baseplates showed better fixation characteristics than their 25 mm circular counterparts; no discernible difference in fixation was observed between flat-back and curved-back baseplates.

BACKGROUND: Proximal humeral fractures are commonly encountered injuries. The development of locking plate technology and reverse shoulder arthroplasty may have changed the treatment patterns of these fractures. METHODS: We used the Statewide Planning and Research Cooperative System database in New York State to determine the incidence of proximal humeral fractures from 1990 through 2010 and the choice of treatment: closed reduction-internal fixation, open reduction-internal fixation (ORIF), hemiarthroplasty (HA), or total shoulder arthroplasty (TSA). RESULTS: The population-adjusted incidence per 100,000 increased from 15.35 in 1990 to 19.4 in 2010 (P < .0001). In patients aged 65 years or older, the incidence increased from 78.9 in 1990 to 101.0 in 2010 (P < .0001). In 1990, 20.4% of proximal humeral fractures were treated operatively; in 2010, this increased to 28.6% (P < .0001). Closed reduction-internal fixation/ORIF accounted for 58.4% of operative cases in 1990, decreasing to 46.6% in 2001 and increasing to 59.4% in 2010. HA was used in 27.1% of operative cases in 1990, increasing to 41% in 2001 and decreasing to 29.4% in 2010. TSA was used in 6.4% of operative cases in 1990, decreasing to 1.5% in 2001 with an increase to 7.5% in 2010. DISCUSSION: The incidence of proximal humeral fractures in patients aged 65 or older increased by 28% between 1990 and 2010, and operative management increased by more than 40%. The use of ORIF increased between 2001 and 2010, corresponding with the use of locking plate technology. There was an associated decrease in HA. TSA increased between 2006 and 2010, corresponding to the use of reverse shoulder arthroplasty.

Reimbursement continues to decrease for orthopaedic surgeons specializing in total joint arthroplasty (TJA). Practice information from the Medical Group Management Association (MGMA) Cost Survey and Private practice Compensation Survey and CMS locality reimbursement data was used to develop a practice model for a TJA specialist performing 300 TJA per year (66% knees, 33% hips, 15% revision surgery), evaluating 3000 outpatient visits per year based on, current Medicare reimbursement rates. Our model shows that the anticipated physician compensation is well below the mean compensation reported for a TJA specialist irrespective of geographic location. When MGMA practice expense data are applied to the Medicare-only model, the salary level is unsustainable. Further decreases in Medicare Part B reimbursement will only worsen the disparity.

The aging baby boomer generation will soon start using tremendous orthopedic surgical resources. This group has also been identified as a group at high risk for having undiagnosed hepatitis C virus (HCV) infection. We conducted a study to assess the prevalence of HCV among orthopedic surgery patients at our institution-using their demographic data to determine whether they represent a unique cohort at high risk for having undiagnosed HCV. We estimated that we operated on as many as 233 patients with undiagnosed HCV in 2011. A cost-effective, universal preoperative HCV screening program may reduce the risk for occupational exposure in orthopedic surgery and significantly benefit public health by bringing undiagnosed patients to treatment. A robust screening program requires several ethical considerations. By offering routine screening to patients, orthopedic surgeons have an opportunity to maintain intraoperative safety and improve the health of the public.

BACKGROUND: Health care payers, including the federal government, increasingly base reimbursement on quality. Payers consider readmission rates after total joint arthroplasty an indicator of quality. The Patient Protection and Affordable Care Act contains provisions that preclude payment of hospital cost associated with joint arthroplasty readmissions occurring within 30 days of discharge. This study evaluates the readmission rates and the incidence of "never events" after inpatient shoulder arthroplasty procedures. METHODS: A retrospective view of all shoulder arthroplasty was performed from 2005 to 2011, with specific emphasis on the readmission rate 30, 60, and 90 days after the procedure. The incidence of never events as defined by the Centers for Medicare and Medicaid Services was also analyzed. RESULTS: During the study period, 680 shoulder arthroplasty procedures were performed. Overall readmission rate was 5.9%. For hemiarthroplasty (HA), total shoulder arthroplasty (TSA), and reverse total shoulder arthroplasty (RTSA), 90-day readmission rates were 8.8%, 4.5%, and 6.6%, respectively. Readmission rates within 30 days of admission were significantly more common for HA and RTSA compared with readmission rates after 30 days. There was a 1.0% incidence of never events, and the incidence associated with each of the 3 arthroplastic procedures did not differ significantly. CONCLUSION: Readmission within the first 90 days after shoulder arthroplasty occurred in 5.9% of patients. There was a 1% incidence of never events. In addition, most readmissions after HA and RTSA occurred within 30 days of discharge. As health care expenditures become more closely scrutinized, readmission rates after shoulder arthroplasty will become increasingly important.

Recent evidence suggests a substantial rise in the number of revision total joint arthroplasty (TJA) procedures performed. The New York State SPARCS inpatient database was utilized to identify revision total shoulder, knee, and hip arthroplasty procedures between 1993 and 2010. Yearly incidence and related epidemiology were analyzed. A total of 1,806 revision TSA, 26,080 revision TKA, and 35,254 revision THA cases were identified. The population-based incidence of these procedures increased 288%, 246%, and 44% respectively (P<0.001). Revision burden for hip arthroplasty decreased from 16.1% in 2001 to 11.5% in 2010 (P<0.001). The rates of revision TSAs and TKAs increased at a substantially faster rate than that of revision THAs. Revision burden for hip arthroplasty steadily has decreased since 2001.

The relationship between pharmaceutical and biomedical technology companies (industry) and medical practitioners has been a topic of discussion and concern for several de- cades. The large monetary payments and extravagant gifts to physicians from these companies have been regulated and largely stopped; however, there still exists an active rapport between physicians and industry. Little formal instruction is given to medical students and residents on what constitutes a conflict of interest when entering these business partnerships. In this study, we presented a set of scenarios depicting industry-physician interactions to medical students, orthopaedic surgery residents, and attending physicians and asked them to decide whether a conflict of interest is depicted. Our goal was to determine whether a disparity exists in the ability to identify conflicts of interest across the levels of training. Of 200 potential participants, 70 provided responses to the survey (35%). Thirty-five (50%) were attending physicians, 18 (25.7%) residents, 12 (17.1%) medical students, and 8 (11.4%) de- clined to provide level of training. There was no significant difference in the ability to identify a conflict of interest across seniority level for the 13 questions. Our results suggest that both medical students and resident physicians are able to identify which interactions with industry pose a possible conflict of interest as accurately as attending physicians can.

There has been a substantial shift in the assessment of outcomes in medicine, including orthopaedic surgery. The quality movement is redefining the delivery of health care. The effect of these changes on orthopaedic surgery and orthopaedic surgeons has been significant and will become increasingly important. Orthopaedic surgeons must become active participants in the quality movement by understanding the basic principles of the movement and how they apply to patient care. A clear understanding of the different agencies (governmental and private) that are leading these initiatives is also essential. Ultimately, active participation in the quality movement will enhance the care provided to patients with musculoskeletal disorders.