Short-term outcomes after primary reverse total shoulder arthroplasty in patients with cervical spine pathology or previous cervical spine surgery compared to those without.

BACKGROUND: Cervical spine (c-spine) and shoulder pathology have been known to cause similar symptoms and often co-exist, making an accurate diagnosis difficult, especially in an elderly population. Reverse total shoulder arthroplasty (rTSA) has been shown to decrease pain and improve quality of life when shoulder pathology is the source of pain and disability. The purpose of this study was to identify the prevalence of c-spine pathology in a cohort of patients who underwent rTSA and to compare postoperative outcome scores to a cohort without c-spine pathology. METHODS: A retrospective review was performed utilizing a single institution's operative records of primary rTSAs. Radiology reports, imaging, and operative reports were reviewed, and presence of any c-spine pathology or previous surgery were recorded. Additionally, postoperative outcome scores (American Shoulder and Elbow Surgeons [ASES], Constant Score, University of California, Los Angeles [UCLA], and Simple Shoulder Test [SST]) were evaluated at >2 years post-rTSA. RESULTS: A total of 438 primary rTSA cases were evaluated. Of these, 143 (32.6%) had documentation of prior c-spine pathology and/or history of previous c-spine surgery. After applying further exclusion criteria, a total of 50 patients with c-spine pathology and 108 patients without c-spine pathology were found to have complete medical records and postoperative outcome scores to allow comparison between groups. Patients without c-spine pathology were found to have statistically higher postoperative UCLA, ASES, and SST scores when compared to patients with c-spine pathology. Patients without c-spine pathology also demonstrated a significant improvement in the difference between their postoperative and preoperative UCLA and ASES scores. CONCLUSION: This study demonstrated a high prevalence of c-spine pathology (32.6%) in a cohort of patients who underwent primary rTSA. Additionally, short-term outcome scores of patients undergoing rTSA with concomitant c-spine pathology are significantly lower than those of patients without a history of c-spine pathology.

Risk factors of instability following reverse total shoulder arthroplasty in patients with no history of shoulder surgery.

Introduction: As its indications expand, reverse total shoulder arthroplasty (rTSA) utilization continues to increase. Though relatively uncommon, instability following rTSA can be associated with significant morbidity and need for subsequent revision and treatment. This case control study aims to characterize factors leading to instability after rTSA, especially in those with no previous shoulder surgery. Methods: 194 rTSAs performed within the study period with appropriate operative indications and follow-up were included. Risk factors used in analysis included age, gender, BMI, ASA class, Charlson comorbidity index (CCI), glenosphere, tray, and liner size. Data was analyzed using a hierarchical binary logistical regression to create a predictive model for instability. Results: Seven patients sustained a post-operative dislocation. Mean time to dislocation was 60.4 weeks. Five required open reduction with placement of either a larger humeral tray or polyethylene spacer. One required open reduction with osteophyte removal, and one was converted to a resection arthroplasty. Dislocators were more likely to have a larger BMI (p = 0.002), higher ASA classification (p = 0.09), and larger liner size (p = 0.01). Conclusion: This study demonstrates a large series of patients successfully treated with rTSA. Dislocations were an uncommon complication, but were clearly associated with higher patient BMI, ASA classification, and increased liner size.

Biomechanical Evaluation of Recurrent Dissociation of Modular Humeral Prostheses.

The purpose of the study was to evaluate the force and torque required to dissociate a humeral head from the unimplanted modular total shoulder replacement system from different manufacturers and to determine if load and torque to dissociation are reduced in the presence of bodily fluids. Impingement, taper contamination, lack of compressive forces, and interference of taper fixation by the proximal humerus have all been reported as possible causes for dissociation. Experimental values determined in this research were compared with literature estimates of dissociation force of the humeral head under various conditions to gain more understanding of the causes of recurrent dissociations of the humeral head. This study examined biomechanical properties under dry and wet conditions under clinically practiced methods. Mean load to dissociation (1513 N ± 508 N) was found to be greater than that exerted by the activities of daily living (578 N) for all implants studied. The mean torque to dissociation was (49.77 N·m ± 19.07 N·m). Analysis of R2 correlation coefficients and p-values (α = 0.05) did not show any significant correlation between dry/bovine, dry/wet, or wet/bovine for load, displacement, or torsional stiffness in the majority of tests performed. Wetting the taper with water or bovine serum did not reduce the dissociation force to a statistically significant degree. Torque and lack of compressive forces at the rotator cuff may be the cause of dissociation at values less than those of activities of daily living. Torque data are provided by this study, but further research is needed to fully appreciate the role of torque in recurrent dissociations.

Opioid requirements in primary versus revision reverse shoulder arthroplasty.

PURPOSE: The purpose of this study is to evaluate the inpatient pain medication use of patients who had a revision shoulder arthroplasty procedure performed and compare them to a cohort of patients who had a primary reverse total shoulder arthroplasty (rTSA) performed to determine whether revision shoulder arthroplasty requires more pain medication.. METHODS: A retrospective review was performed on patients undergoing revision arthroplasty (n = 75) and primary rTSA (n = 340). Inpatient medication records were reviewed to tabulate the visual analog pain (VAS) all narcotic medication use, and total morphine equivalent units (MEUs) were calculated for the duration of the inpatient stay. RESULTS: There was no significant difference between groups regarding age, sex, body mass index, Charlson Comorbidity Index, American Society of Anesthesiologists score, preoperative narcotic pain medication use, tobacco use, postoperative VAS scores or hospital length of stay. There were no predictors of total postoperative MEUs identified. Overall, patients in the revision arthroplasty group received significantly less total MEUs than those in the primary rTSA group, 134.96 MEUs vs. 69.79 MEUs, respectively (p < .0005). CONCLUSION: The perceived notion that revision shoulder arthroplasty is more painful may cause providers to be more inclined to increase narcotic use, or use more invasive pain control techniques. Based on these data, we found that revision shoulder arthroplasty did not require an increased opioid requirement, longer length of stay or increase VAS, suggesting that these patients can often be managed similarly to primary rTSA.

Polyethylene Liner Dissociation after Reverse Shoulder Arthroplasty Dislocation: a Case Series.

Reverse shoulder arthroplasty is a common procedure. While dislocation is a common complication, there are few reports documenting dislocation with associated polyethylene liner dissociation from the humeral tray. There have been 4 instances of this occurrence over 9 years at our institution, and there are specific radiographic clues for diagnosis. Recognizing polyethylene liner dissociation on imaging is important prior to treatment. In a "routine" dislocation, closed reduction may be attempted but when the polyethylene is dissociated, open reduction is the only treatment option, as closed reduction can damage the components. Dislocations with polyethylene dissociation may not be initially recognized, prompting a non-operative period leading to wear and metallosis. These 4 cases demonstrate key findings present on imaging to recognize the difference between a dislocation with and without polyethylene liner dissociation, namely the subluxation appearance rather than dislocation.

Clinical implications of scapular notching at 2 and 5-year follow-up after reverse total shoulder arthroplasty.

OBJECTIVE: Scapular notching is a unique radiographic sequela of reverse total shoulder arthroplasty (rTSA) with unclear long-term clinical consequences. METHODS: Our retrospective review of a single surgeon, single implant, primary rTSA database investigates the incidence of scapular notching at 2 and 5-year follow-up. Various patient outcome scores were also obtained. RESULTS: Of 158 primary rTSAs performed, 82 (52%) patients completed 2-year and subsequent 5-year follow-up. The incidence of scapular notching at 2 and 5-years was 11.9% and 19.5%, respectively. CONCLUSION: Scapular notching negatively affects validated post-operative outcome scores, active range of motion and total complications, and furthermore increases with time.

Routine postoperative laboratory tests are unnecessary after primary reverse shoulder arthroplasty.

BACKGROUND: Obtaining postoperative laboratory studies after primary reverse shoulder arthroplasty (RSA) is a common practice. However, justification of this practice remains unclear. This study assesses the utility of routine postoperative laboratory studies in RSA. METHODS: The electronic medical records of 369 patients who underwent RSA over 10 years were retrospectively reviewed. A total of 213 patients qualified for analysis. Primary outcomes were intervention related to abnormal laboratory values, length of stay, and 90-day emergency department visits/readmissions. Multivariate logistic regression analysis was performed to identify risk factors associated with abnormal laboratory values and postoperative visits/readmissions. RESULTS: Of 213 patients analyzed, 188 (88.7%) had abnormal postoperative laboratory values: 69% had an abnormal hemoglobin (Hgb) or hematocrit level, but only 12% underwent interventions. Lower preoperative Hgb was a significant predictor of receiving a transfusion. A significant association existed between abnormal postoperative electrolyte and creatinine levels with lower body mass index (BMI) and higher Charlson Comorbidity Index (CCI). Only 4 patients (1.8%) received non-transfusion related intervention. Emergency department visits were not statistically different between patients with positive or negative laboratory tests (P = .73). CONCLUSION: Because 87.3% of laboratory studies did not influence patient management, we recommend against routine testing for primary RSA. This study demonstrates that the practice of obtaining routine postoperative laboratory studies is not justified. We recommend selectively obtaining a postoperative basic metabolic profile in patients with increased American Society of Anesthesiologists classification and/or CCI with a lower BMI. We also recommend selectively ordering postoperative complete blood count in patients with a lower preoperative Hgb.

Update on Misrepresentation of Research Publications Among Orthopaedic Surgery Residency Applicants.

BACKGROUND: Our 2 previous studies (1999, 2007) examining misrepresentation of research publications among orthopaedic residency applicants revealed rates of misrepresentation of 18.0% and 20.6%, respectively. As the residency selection process has become more competitive, the number of applicants who list publications has increased. The purpose of this study was to determine current rates of research misrepresentation by orthopaedic surgery applicants. METHODS: We reviewed the publication listings and research section of the Common Application Form from the Electronic Residency Application Service (ERAS) for all applicants applying to 1 orthopaedic residency program. The PubMed-MEDLINE database was principally used to search for citations. The PubMed Identifier (PMID) number was used; if no PMID number was listed, a combination of authors or the title of the work was used. If the citations were not found through PubMed, a previously developed algorithm was followed to determine misrepresentation. Misrepresentation was defined as (1) nonauthorship of a published article in which authorship was claimed, (2) claimed authorship of a nonexistent article, or (3) self-promotion to a higher authorship status within a published article. RESULTS: Five hundred and seventy-three applicants applied to our institution for residency in 2016 to 2017: 250 (43.6%) of 573 applicants did not list a publication, whereas 323 (56.4%) of 573 applicants listed ≥1 publication. We found 13 cases of misrepresentation among a total of 1,100 citations (1.18% in 2017 versus 18.0% in 1999 and 20.6% in 2007, p < 0.001). Ten cases of misrepresentation were self-promotion to a higher authorship status. There were 2 cases of claimed authorship of an article that could not be found. Only 1 applicant misrepresented more than once. CONCLUSIONS: Based on our findings, orthopaedic surgery residency applicants are accurately representing their publication information. The incorporation of the PMID number on the ERAS application has streamlined the process for finding publications, and has possibly encouraged veracity on residency applications. Faculty involved in the resident selection process should be aware of the significant decline in the rate of misrepresentation by medical students applying for orthopaedic surgery residency versus the rate in our prior studies.

Conversion to Reverse Total Shoulder Arthroplasty with and without Humeral Stem Retention: The Role of a Convertible-Platform Stem.

BACKGROUND: Revision shoulder arthroplasty is a technically challenging procedure. It is associated with increased blood loss and operative time, and it frequently necessitates revision implants, augments, and bone-grafting. Shoulder arthroplasty systems with a convertible-platform humeral stem have been developed to reduce the complexity of revision procedures by eliminating the need for humeral component explantation when converting from anatomic shoulder arthroplasty (hemiarthroplasty or total shoulder arthroplasty) to reverse total shoulder arthroplasty (rTSA). METHODS: A multicenter, retrospective analysis involving 102 consecutive shoulders (102 patients) that underwent revision of an anatomic shoulder arthroplasty to an rTSA was conducted. During the revision, 73 of the shoulders needed exchange of the humeral stem (the exchange group) and 29 had retention of a convertible-platform humeral component (the retention group). Patient demographics, operative time, blood management, range of motion, complications, and patient-reported outcomes were compared between the 2 groups. RESULTS: Patients with retention had significantly shorter operative time (mean and standard deviation, 130 ± 48 versus 195 ± 58 minutes; p < 0.001) and lower estimated blood loss (292 ± 118 versus 492 ± 334 mL; p = 0.034). The rate of intraoperative complications was lower in the retention group (0% versus 15%; p = 0.027). Patients with retention had slightly better postoperative range of motion (active external rotation, 26° ± 23° versus 11° ± 23° [p = 0.006]; active forward elevation, 112° ± 37° versus 96° ± 33° [p = 0.055]). CONCLUSIONS: Shoulder arthroplasty systems that utilize a convertible-platform humeral stem offer an advantage for rTSA conversion in that a well-fixed, well-positioned humeral stem can be retained. There were significantly fewer complications as well as significantly decreased blood loss and operative time when a convertible-platform stem was utilized (p < 0.050). LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Scapula fracture incidence in reverse total shoulder arthroplasty using screws above or below metaglene central cage: clinical and biomechanical outcomes.

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) is a viable treatment option for rotator cuff tear arthropathy but carries a complication risk of scapular fracture. We hypothesized that using screws above the central glenoid axis for metaglene fixation creates a stress riser contributing to increased scapula fracture incidence. Clinical type III scapular fracture incidence was determined with screw placement correlation: superior screw vs. screws placed exclusively below the glenoid midpoint. Cadaveric RTSA biomechanical modeling was employed to analyze scapular fractures. METHODS: We reviewed 318 single-surgeon single-implant RTSAs with screw correlation to identify type III scapular fractures. Seventeen cadaveric scapula specimens were matched for bone mineral density, metaglenes implanted, and fixation with 2 screw configurations: inferior screws alone (group 1INF) vs. inferior screws with one additional superior screw (group 2SUP). Biomechanical load to failure was analyzed. RESULTS: Of 206 patients, 9 (4.4%) from the superior screw group experienced scapula fractures (type III); 0 fractures (0/112; 0%) were identified in the inferior screw group. Biomechanically, superior screw constructs (group 2SUP) demonstrated significantly (P < .05) lower load to failure (1077 N vs. 1970 N) compared with constructs with no superior screws (group 1INF). There was no significant age or bone mineral density discrepancy. CONCLUSION: Clinical scapular fracture incidence significantly decreased (P < .05) for patients with no screws placed above the central cage compared with patients with superior metaglene screws. Biomechanical modeling demonstrates significant construct compromise when screws are used above the central cage, fracturing at nearly half the ultimate load of the inferior screw constructs. We recommend use of inferior screws, all positioned below the central glenoid axis, unless necessary to stabilize the metaglene construct.

Core decompression and arthroplasty outcomes for atraumatic osteonecrosis of the humeral head.

BACKGROUND: Humeral head osteonecrosis treatment varies depending on the stage and symptoms. Successful outcomes for humeral head core decompression for stage I/II disease in chronic steroid-induced (CSI) osteonecrosis have been reported, but fewer data exist for sickle cell disease (SCD) etiology. Resurfacing and hemiarthroplasty or total shoulder arthroplasty (TSA) are common for advanced collapse, with mixed results. METHODS: We evaluate radiographic and functional outcomes after procedures for humeral head atraumatic avascular necrosis (HAAVN), decompression efficacy in CSI and SCD populations, and report outcomes of advanced disease requiring arthroplasty. Twenty-five shoulders were treated surgically for HAAVN. Post-traumatic AVN patients were excluded. Stage I/II disease received core decompression and ultrasound bone stimulation. Stage III received surface replacement or hemiarthroplasty, and arthroplasty was performed for stage IV/V. Radiographs and clinical scores were recorded preoperatively and postoperatively. RESULTS: Included were 25 HAAVN shoulders (13 SCD and 12 CSI). Eleven shoulders (stage I/II disease) underwent core decompression. Seven of 8 shoulders (88%) progressed to stage III/IV after decompression. All SCD patients progressed to collapse. The procedure in 19 shoulders was surface replacement, hemiarthroplasty, or TSA. Constant, American Shoulder and Elbow Surgeons, Simple Shoulder Test-12, and University of California Los Angeles Shoulder scores were significantly higher at 1- and 2-year follow-up with arthroplasty; 13 of 16 arthroplasty patients (81%) had satisfactory to excellent results. One surface replacement was revised to reverse TSA. CONCLUSIONS: Results suggest core decompression for AVN in SCD patients does not alter osteonecrosis progression and humeral head collapse. Resurfacing and hemiarthroplasty are viable treatment options for stage III, whereas shoulder replacement for stage IV/V disease appears to offer better functional results.

Reverse Shoulder Arthroplasty Augments for Glenoid Wear. Comparison of Posterior Augments to Superior Augments.

INTRODUCTION: Patients who are candidates for a reverse total shoulder arthroplasty (rTSA) may have varying amounts and patterns of glenoid wear. The usual treatment of these deformities has been eccentric reaming or bone grafting. Eccentric reaming often removes a large amount of subchondral bone. Bone grafting is technically more difficult and introduces another mode of failure if the graft does not heal. The purpose of this study is to evaluate patients undergoing a rTSA with concomitant superior or posterior glenoid wear who were treated with a superior augmented baseplate (SAB) or posterior augmented baseplate (PAB) without eccentric reaming or bone grafting. MATERIALS AND METHODS: Prospectively obtained data were queried from a multi-institutional IRB-approved database. Preoperative and postoperative data were analyzed from 39 patients who received a primary rTSA with either an 8° PAB or a 10° SAB and a minimum of 2 years follow-up. Twenty-four (10 females and 14 males, aged 72.3 ± 8.2 years) received a primary rTSA shoulder with a PAB. Fifteen patients (4 females and 11 males, aged 71.7 ± 9.2 years) received a primary rTSA shoulder with a SAB. Each patient was scored preoperatively and at latest follow-up using the SST, UCLA, ASES, Constant, and SPADI metrics. Active abduction, forward flexion, and active and passive external rotation with the arm at the side were also measured. The average follow-up for rTSA patients with a PAB was 25.6 ± 3.1 months, and the average follow-up for rTSA patients with a SAB was 32.5 ± 6.5 months. A Student's two-tailed, unpaired t-test was used to identify differences in preoperative and postoperative results, where p < 0.05 denoted a significant difference. RESULTS: All patients in both groups demonstrated significant improvements in pain and function following treatment with the reverse shoulder arthroplasty. The PAB rTSA cohort had a scapular notching rate of 6.3%, whereas the SAB rTSA cohort had a scapular notching rate of 14.3%. The PAB outperformed the SAB with the ASES, Constant, and active forward elevation measures. DISCUSSION: The PAB group outperformed the SAB group with the ASES and Constant outcome scores and forward flexion. The reason for this is unknown; however, it may be due to the posterior augment baseplate itself tensioning the remaining external rotators better than the superior augment, or it may be that the posterior augment group had a better posterior cuff. Both implant groups had no revisions or dislocations and had a low notching rate. It appears that a SAB for superior glenoid wear and a PAB for posterior glenoid wear are viable simple solutions in patients undergoing a rTSA, where each preserves glenoid bone and eliminates the need for glenoid bone grafting.

Revision Total Shoulder Arthroplasty without Humeral Component Removal. A Preliminary Report on the Role of a Platform Humeral Component.

BACKGROUND: Revision total shoulder arthroplasty to a reverse system without removing the humeral component-- i.e., a platform system--has been in use since 2006. This preliminary report compares the outcomes of revision total shoulder replacement in patients who underwent revision utilizing a platform system as compared to those patients requiring stem removal. METHODS: The data banks from two academic centers were utilized to review patients who underwent revision total shoulder surgery requiring removal of a well fixed humeral stem and those revised with a well fixed platform humeral stem. All patients underwent revision to reverse total shoulder arthroplasty. Measured variables were pre and postoperative Constant scores, blood loss, operating room time, complications, and cost. RESULTS: The use of a platform system resulted in fewer complications, less operating room time, and a decrease in blood loss (p < 0.05). The Constant scores were not significantly different between the two groups. The cost of implants and operating room time was also less in the platform system group. CONCLUSION: Revision total shoulder arthroplasty utilizing a platform system that does not require humeral component removal resulted in a significant decrease in complications, blood loss, and operating room time compared with revisions that did not utilize a platform system. The Constant score was similar between the two groups. The overall cost of the procedure was less when the platform system was used.

Infection Prevention in Shoulder Surgery.

The microbiome of the shoulder demonstrates distinctive differences to other orthopaedic surgical sites. Recent studies have demonstrated that the most common organisms found in deep shoulder infections are coagulase-negative staph lococcal species and Propionibacterium acnes . Many studies support diligent hand washing, decreasing operative time, routine glove changing, minimizing operating room traffic, and covering instruments as means for decreasing the risk of deep infection. On the other hand, hair clipping and the use of adhesive drapes may have little effect on decreasing the incidence of deep infection. Although generally considered the most efficacious skin preparation solution, chlorhexidine gluconate has minimal effect on eradication of P. acnes from the surgical site; however, the addition of preoperative topical applications of benzoyl peroxide to standard surgical preparation has shown promise in decreasing the rate of P . acnes culture positivity. Additionally, the use of local antibiotic formulations seems to be an effective means of preventing deep infection.

Proximal humeral fractures: pin, plate, or replace.

Proximal humeral fractures are becoming increasingly common in individuals older than 60 years, with only fractures of the hip and distal radius occurring with a higher frequency. Most proximal humeral fractures can be managed without surgery; however, if a fracture is displaced or angulated, surgical treatment may be required. There are four main options for the surgical management of proximal humeral fractures: minimally invasive percutaneous reduction and fixation, open reduction and periarticular plating, hemiarthroplasty, and reverse total shoulder arthroplasty.

Infection after primary anatomic versus primary reverse total shoulder arthroplasty.

BACKGROUND: Deep periprosthetic infection is a serious complication after total shoulder arthroplasty (TSA) and is associated with suboptimal clinical results. This retrospective study aimed to determine whether a difference in infection rate existed after primary anatomic TSA (aTSA) and primary reverse TSA (rTSA). METHODS: A TSA database was retrospectively reviewed to identify primary TSAs performed from 2004 to 2012 and isolate cases of confirmed deep periprosthetic infection. Data collected included age, sex, preoperative diagnosis, previous nonarthroplasty operative history, implant type, and infecting organism. RESULTS: From 814 primary TSAs performed, deep periprosthetic infections were confirmed in 16 shoulders. Infections occurred in 6 aTSAs and 10 rTSAs, with no significant difference among the prosthesis types. Pathogens included Staphylococcus spp, Propionibacterium acnes, and Escherichia coli. In the subgroup of shoulders with no previous operations, no significant difference in infection rate was found among the prosthesis types. Shoulders with previous nonarthroplasty operations undergoing primary TSA exhibited a significantly higher (P = .016) infection rate compared with shoulders with no operative history. Both aTSA and rTSA performed in previously operated-on shoulders demonstrated higher infection rates compared with shoulders with no prior operative intervention. The infection rate was significantly higher (P = .016) in the rTSA group. CONCLUSIONS: There is no difference in infection rate after primary aTSA and primary rTSA in shoulders that have not undergone previous operative interventions. Infection is more likely to develop in shoulders undergoing primary rTSA that have had one or more nonarthroplasty operative procedures.

Evaluation and treatment of the infected shoulder arthroplasty.

Infection after shoulder arthroplasty remains one of the most common postoperative complications. Treatment options range from debridement, appropriate antibiotic regimen, and retaining the implant to resection arthroplasty in the elderly medically challenged patient. We review the diagnostic challenges and treatment options for periprosthetic infections involving the shoulder. It appears that early detection, isolation of the infecting organism, and aggressive debridement with appropriate antibiotic treatment is the most important component of a successful treatment program designed to eradicate the infection. This early treatment which in most cases is combined with a two-stage approach (with an interim antibiotic spacer) provides the best opportunity to obtain a reasonably painless and functional shoulder arthroplasty.

Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty.

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.

Perspective: Integrating research into surgical residency education: lessons learned from orthopaedic surgery.

Orthopaedic research has advanced tremendously in parallel with accelerated progress in medical science. Possession of a fundamental understanding of basic and clinical science has become more essential than previously for orthopaedic surgeons to be able to translate advances in research into clinical practice. The number of medical graduates with prior education in scientific research who choose to pursue careers in orthopaedic surgery is small. Therefore, it is important that a core of research education be included during residency training to ensure the continued advancement of the clinical practice of orthopaedics. The authors examine some of the challenges to a comprehensive research experience during residency, including deficient priority, inadequate institutional infrastructure, financial strain on residency budgets, restricted time, and an insufficient number of mentors to encourage and guide residents to become clinician-scientists. They also present some strategies to overcome these challenges, including development and expansion of residency programs with clinician-scientist pathways, promotion of financial sources, and enhancement of opportunities for residents to interact with mentors who can serve as role models. Successful integration of research education into residency programs will stimulate future orthopaedic surgeons to develop the critical skills to lead musculoskeletal research, comprehend related discoveries, and translate them into patient care. Lessons learned from incorporating research training within orthopaedic residency programs will have broad application across medical specialties-in both primary and subspecialty patient care.