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.

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.

When performing revision shoulder surgery, it is important that the surgeon understands why the index procedure failed and has a clear plan to address problems in the revision procedure. The most common cause of failure after anterior instability shoulder surgery is a failure to treat the underlying glenoid bone loss. For most defects, a Latarjet transfer can effectively restore anterior glenoid bone stock and restore shoulder stability. Persistent anterior shoulder pain after rotator cuff surgery may be the result of missed biceps pathology. This can be effectively treated via a biceps tenodesis. The most difficult failures to treat after acromioclavicular joint reconstruction surgery are those involving fractures of either the coracoid or the clavicle. Clavicle hook plates can be used as supplemental fixation during the treatment of these fractures to help offload the fracture site and allow healing while restoring stability to the acromioclavicular articulation. A failed hemiarthroplasty for a proximal humeral fracture frequently results when the tuberosities fail to heal correctly. This complication can be avoided by paying close attention to the implant position and the tuberosity fixation. If hemiarthroplasty is unsuccessful, the patient is best treated with conversion to a reverse shoulder arthroplasty.

The unsustainable rising cost of medical care is creating financial pressures that will critically alter the way that health care is paid for and delivered. Limited resources dictate that physicians must become more efficient at providing high quality care. In an effort to provide financial incentive for delivering quality care, the federal government instituted value-based purchasing to transform Medicare from a passive payer of claims to an active purchaser of medical care. Healthcare providers must follow the basic tenants of certain quality principles to maximize reimbursement under the value-based purchasing system.

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.

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.

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.

UNLABELLED:Worldwide, the usage of both anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthro- plasty (rTSA) has increased significantly due, in part, to the predictability of acceptable outcomes achieved with each prosthesis type. This study quantifies outcomes using five different metrics and compares results using one platform total shoulder arthroplasty system that utilizes the same humeral component and instrumentation to perform both aTSA or rTSA. METHODS:200 patients were treated by two orthopaedic surgeons using either aTSA or rTSA. 73 patients received aTSA for treatment of osteoarthritis (OA), and 127 patients received rTSA for treatment of rotator cuff tear arthro- plasty (CTA). Each was scored preoperatively, and at latest follow-up using the SST, UCLA, ASES, Constant, and SPADI metrics, motion was also quantified. The average follow-up for all patients was 31.4 ± 9.7 months. RESULTS:All patients demonstrated significant improvements in pain and function following treatment of OA with aTSA and treatment of CTA with rTSA. No instances of instability or glenoid loosening were reported in either cohort; one instance of infection occurred in the rTSA cohort. aTSA was associated with significantly higher pre- and postoperative outcome scores and significantly larger pre- and postoperative range of motion than rTSA. However, rTSA was demonstrated to be significantly more effective at improving outcome scores, active forward flexion, and strength than was aTSA. DISCUSSION AND CONCLUSIONS/CONCLUSIONS:Significant improvements in outcome scores were observed for both aTSA and rTSA using one platform shoulder system at a mean follow-up of 31.4 months. Significant differences were observed between prosthesis type and between scoring metrics, particularly between the Constant and ASES scoring metrics. Additional and longer term follow-up is required to confirm these observed differences.