Faculty Bibliography

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.

Loosening of the glenoid component is a frequent cause of failure of total shoulder arthroplasty (TSA). The etiology of glenoid component loosening is multifactorial and includes aseptic osteolysis, rotator cuff insufficiency, soft tissue instability, and infection. A loose glenoid component is frequently associated with a substantial loss of glenoid bone, which necessitates additional procedures to implant a new component. Several studies have shown that patients with a new glenoid component have better clinical outcomes, which makes successful glenoid reimplantation a priority. The reconstructive options when facing a loose glenoid component in anatomic total shoulder arthroplasty include the established techniques of reaming the high side or bone grafting the deficient glenoid combined with a one or two stage revision. Augmented glenoid components may allow surgeons to limit eccentric reaming or the extent of bone grafting necessary in a bone deficient glenoid. The reverse total shoulder arthroplasty (rTSA) is emerging as a useful reconstructive option capable of addressing bony and soft tissue problems encountered in revision TSA. The ream-and-run procedure remains the least desirable option in the face of significant glenoid bone deficiency. The increasing use of augmented glenoids and rTSA in revision TSA may provide opportunities for new areas of clinical outcomes research in this challenging reconstructive problem.

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.

Subscapularis tenotomy for total shoulder arthroplasty has been the standard approach for shoulder surgeons that utilize the deltopectoral approach. The risk of subscapularis insufficiency after this approach has been well documented. In order to avoid subscapularis complications, Lafosse reported a technique for total shoulder arthroplasty that utilizes a trans-deltoid approach through the rotator interval that yielded satisfactory clinical outcomes. However, he also reported concerns about humeral head undersizing and inadequate osteophyte resection. We present an alternative subscapularis preserving technique that is performed through the deltopectoral interval and allows complete osteophyte excision and accurate humeral head sizing. This technique requires modified instrumentation and is facilitated by the use of an adaptable prosthesis with dual eccentricity. Case examples using this technique are presented.

PURPOSE: This study quantifies the ability of humeral retroversion, glenoid tilt, bone graft, and varying prosthesis design parameters to restore anatomic muscle length and deltoid wrapping with reverse shoulder arthroplasty. METHODS: A computer model simulated abduction and internal and external rotation for a normal shoulder, the RSP reverse shoulder, the Equinoxe reverse shoulder, and the Grammont reverse shoulder when implanted using various implantation methods. The length of eight different muscles and the deltoid wrapping angle were quantified to evaluate the ability of each implantation method and design to restore anatomic muscle tensioning. RESULTS: Each reverse shoulder shifted the center of rotation medially and inferiorly relative to the normal shoulder and caused a corresponding shift in the position of the humerus. Each reverse shoulder elongated each head of the deltoid and shortened the internal and external rotators relative to the normal shoulder. The surgical techniques and prosthesis designs, which resulted in a more lateral humeral position, were associated with more deltoid wrapping and better tensioning of the anterior and posterior shoulder muscles. CONCLUSIONS: Muscle tensioning and deltoid wrapping can be substantially altered by surgical implantation meth- ods using the Grammont reverse shoulder. However, the results of this study demonstrate that more anatomic muscle tensioning and improved deltoid wrapping are achieved using alternative prosthesis designs that better restore the lateral position of the humerus.

PURPOSE: The purpose of this study is to validate a reverse shoulder computer impingement model and quantify the impact of implant position on scapular impingement by comparing it to that of a radiographic analysis of 256 patients who received the same prosthesis and were followed postoperatively for an average of 22.2 months. METHODS: A geometric computer analysis quantified anterior and posterior scapular impingement as the humerus was internally and externally rotated at varying levels of abduction and adduction relative to a fixed scapula at defined glenoid implant positions. These impingement results were compared to radiographic study of 256 patients who were analyzed for notching, glenoid baseplate position, and glenosphere overhang. RESULTS: The computer model predicted no impingement at 0 degrees humeral abduction in the scapular plane for the 38 mm, 42 mm, and 46 mm devices when the glenoid baseplate cage peg is positioned 18.6 mm, 20.4 mm, and 22.7 mm from the inferior glenoid rim (of the reamed glenoid) or when glenosphere overhang of 4.6 mm, 4.7 mm, and 4.5 mm was obtained with each size glenosphere, respectively. When compared to the radiographic analysis, the computer model correctly predicted impingement based upon glenoid base- plate position in 18 of 26 patients with scapular notching and based upon glenosphere overhang in 15 of 26 patients with scapular notching. CONCLUSIONS: Reverse shoulder implant positioning plays an important role in scapular notching. The results of this study demonstrate that the computer impingement model can effectively predict impingement based upon implant positioning in a majority of patients who developed scapular notching clinically. This computer analysis provides guidance to surgeons on implant positions that reduce scapular notching, a well-documented complication of reverse shoulder arthroplasty.