Faculty Bibliography

BACKGROUND:Knowledge of the minimal clinically important difference (MCID) for different shoulder outcome metrics and range of motion after total shoulder arthroplasty (TSA) can be useful to establish a minimum threshold of improvement that defines successful treatment. This study quantifies how MCID varies with different prosthesis types, patient age, gender, and length of follow-up after TSA. METHODS:A total of 466 anatomic TSA (aTSA) and reverse TSA (rTSA) with 2-year minimum follow-up were performed by 13 shoulder surgeons. The MCID for the American Shoulder and Elbow Surgeons, Constant, University of California Los Angeles Shoulder Rating Scale, Simple Shoulder Test, Shoulder Pain and Disability Index, global shoulder function, and visual analog scale for pain scores, as well as active abduction, forward flexion, and external rotation, were calculated for different prosthesis types and patient cohorts using an anchor-based method. RESULTS:The anchor-based MCID results were American Shoulder and Elbow Surgeons = 13.6 ± 2.3, Constant score = 5.7 ± 1.9, University of California Los Angeles Shoulder Rating Scale = 8.7 ± 0.6, Simple Shoulder Test score = 1.5 ± 0.3, Shoulder Pain and Disability Index score = 20.6 ± 2.6, global shoulder function = 1.4 ± 0.3, pain visual analog scale  = 1.6 ± 0.3, active abduction = 7° ± 4°, active forward flexion = 12° ± 4°, and active external rotation = 3° ± 2°. Female gender and rTSA were associated with lower MCID values compared with male gender and aTSA patients. CONCLUSION/CONCLUSIONS:The minimum improvement necessary for patients to achieve a result they believe is clinically meaningful after aTSA and rTSA is nominal and was achieved by at least 80% of the patients. Future endeavors should investigate the influence of different anchor questions on the MCID calculation.

OBJECTIVES/OBJECTIVE:To understand the personality factors associated with orthopedic surgery resident performance. DESIGN/METHODS:A prospective, cross-sectional survey of orthopedic surgery faculty that assessed their perceptions of the personality traits most highly associated with resident performance. Residents also completed a survey to determine their specific personality characteristics. A subset of faculty members rated the performance of those residents within their respective program on 5 dimensions. Multiple regression models tested the relationship between the set of resident personality measures and each aspect of performance; relative weights analyses were then performed to quantify the contribution of the individual personality measures to the total variance explained in each performance domain. Independent samples t-tests were conducted to examine differences between the personality characteristics of residents and those faculty identified as relevant to successful resident performance. SETTING/METHODS:throughout the United States. The level of clinical care provided by participating institutions varied. PARTICIPANTS/METHODS:Data from 175 faculty members and 266 residents across 12 programs were analyzed. RESULTS:The personality features of residents were related to faculty evaluations of resident performance (for all, p < 0.01); the full set of personality measures accounted for 4%-11% of the variance in ratings of resident performance. Particularly, the characteristics of agreeableness, neuroticism, and learning approach were found to be most important for explaining resident performance. Additionally, there were significant differences between the personality features that faculty members identified as important for resident performance and the personality features that residents possessed. CONCLUSION/CONCLUSIONS:Personality assessments can predict orthopedic surgery resident performance. However, results suggest the traits that faculty members value or reward among residents could be different from the traits associated with improved resident performance.

Introduction: Chlorhexidine gluconate (CHX) is widely used as a preoperative surgical skin-preparation solution and intra-wound irrigation agent, with excellent efficacy against wide variety of bacteria. The cytotoxic effect of CHX on local proliferating cells following orthopaedic procedures is largely undescribed. Our aim was to investigate the in vitro effects of CHX on primary fibroblasts, myoblasts, and osteoblasts. Methods: Cells were exposed to CHX dilutions (0%, 0.002%, 0.02%, 0.2%, and 2%) for either a 1, 2, or 3-minute duration. Cell survival was measured using a cytotoxicity assay (Cell Counting Kit-8). Cell migration was measured using a scratch assay: a "scratch" was made in a cell monolayer following CHX exposure, and time to closure of the scratch was measured. Results: All cells exposed to CHX dilutions of ≥ 0.02% for any exposure duration had cell survival rates of less than 6% relative to untreated controls (p < 0.001). Cells exposed to CHX dilution of 0.002% all had significantly lower survival rates relative to control (p < 0.01) with the exception of 1-minute exposure to fibroblasts, which showed 96.4% cell survival (p = 0.78). Scratch defect closure was seen in < 24 hours in all control conditions. However, cells exposed to CHX dilutions ≥ 0.02% had scratch defects that remained open indefinitely. Conclusions: The clinically used concentration of CHX (2%) permanently halts cell migration and significantly reduces survival of in vitro fibroblasts, myoblasts, and osteoblasts. Further in vivo studies are required to examine and optimize CHX safety and efficacy when applied near open incisions or intra-wound application.

STUDY DESIGN: In vitro laboratory study. OBJECTIVE: The purpose of this study was to identify the effect of dilute povidone-iodine (PVI) solutions on human osteoblast, fibroblast and myoblast cells in vitro. SUMMARY OF BACKGROUND DATA: Dilute PVI wound lavage has been used successfully in spine and joint arthroplasty procedures to prevent post-operative surgical site infection, but their biologic effect on host cells is largely unknown. METHODS: Human primary osteoblasts, fibroblasts, and myoblasts were expanded in cell culture and subjected to various concentrations of PVI (0%, 0.001%, 0.01%, 0.1%, 0.35%, 1%) for 3 minutes. To assess the effect of PVI on cell migration, a scratch assay was performed, in which a "scratch" was made by a standard pipette tip in a cell monolayer following PVI exposure, and time to closure of the scratch was evaluated. Cell survival and proliferation was measured 48 hours post-PVI exposure using a cell viability and cytotoxicity assay. RESULTS: Closure of the scratch defect in all cell monolayers was achieved in < 24 hours in untreated controls and following exposure to PVI concentrations < 0.1%. The scratch defect remained open indefinitely following exposure to PVI concentrations of >/= 0.1%. PVI concentrations < 0.1% did not have significant effect on survival rates compared with control for all cell types. Cells exposed to PVI >/= 0.1% had cell survival rates of less than 6% (p < 0.05). CONCLUSIONS: Clinically used concentration of PVI (0.35%) exerts a pronounced cytotoxic effect on osteoblasts, fibroblast, and myoblasts in vitro. Further investigation is required to systematically study the effect of PVI on tissue healing in vivo and also determine a safe and clinically potent concentration for PVI lavage. LEVEL OF EVIDENCE: N/A.

Arthroscopic SLAP tear repair has become an increasingly used treatment for patients presenting with symptomatic SLAP tears after failed nonoperative management. Debridement, SLAP repair, and open or arthroscopic biceps tenodesis or tenotomy have been used for the treatment of SLAP tears. Various techniques for repair have been described, and furthermore, there is a high incidence of concomitant pathology of the shoulder. Repair remains an excellent option in isolated SLAP tears amenable to repair, with excellent outcomes in well-indicated patients. We present a method for repairing a SLAP tear using standard suture anchor fixation, anterior and posterior portals, and an accessory portal of Wilmington. Adequate labral repair can be achieved with this technique in patients with no concomitant biceps pathology. This report highlights this technique for SLAP repair in patients with isolated symptomatic SLAP tears that have failed conservative management.

BACKGROUND: Intraoperative anesthetic typically consists of either general anesthesia (GA) or isolated regional anesthesia (RA). METHODS: A retrospective propensity-matched cohort analysis on patients undergoing TSA was performed to determine differences between GA and RA in regard to patient population, complications, LOS and hospital readmission. RESULTS: 4158 patients underwent TSA with GA or isolated RA. Propensity-matching resulted in 912 patients in each cohort. RA had lower overall in-hospital complications and greater homebound discharge disposition with lower 90-day readmission rates than GA. CONCLUSION: After TSA, isolated RA was associated with lower in-hospital complications, readmission rates and odds of hospital readmission than GA.

BACKGROUND:This study quantifies the rate of improvement after anatomic and reverse total shoulder arthroplasty; a better understanding of the rate of improvement associated with each prosthesis type may better establish patient expectations for recovery. METHODS:Prospectively collected data on 1,183 patients who underwent either anatomic total shoulder arthroplasty (n = 505) or reverse total shoulder arthroplasty (n = 678) were collected. The Simple Shoulder Test (SST), University of California at Los Angeles (UCLA) Shoulder, American Shoulder and Elbow Surgeons (ASES), Constant, and Shoulder Pain and Disability Index (SPADI) scores, along with range of motion, were recorded preoperatively and at routine postoperative time points. All included patients had a minimum follow-up of 2 years. The rate of improvement of these outcome measures was quantified for patients who underwent anatomic total shoulder arthroplasty and those who underwent reverse total shoulder arthroplasty to compare recovery over time. RESULTS:In this study, 3,587 visits by 1,183 patients were analyzed and several differences between prosthesis types were noted. Patients who underwent reverse total shoulder arthroplasty experienced larger improvements in the Constant score and active forward flexion, and patients who underwent anatomic total shoulder arthroplasty demonstrated better improvement in external rotation compared with patients who underwent reverse total shoulder arthroplasty at nearly all time points. By 72 months, improvement in flexion and abduction decreased for each prosthesis type, but in particular for reverse total shoulder arthroplasty. Full improvement was achieved by 24 months, although the majority of improvement was achieved in the first 6 months, with all 5 scoring metrics following a similar rate of improvement. The ASES, SPADI, and UCLA Shoulder scores closely mirrored each other in the magnitude of improvement, and the SST score demonstrated the largest improvement and the Constant score demonstrated the smallest improvement for both anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty. CONCLUSIONS:Both anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty reliably result in improved patient outcomes. However, anatomic total shoulder arthroplasty more reliably improves range of motion, particularly external rotation. Most improvement occurs by 6 months, with some additional improvement up to 2 years for both anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty. Although the indications for anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty are substantially different, in addition to the biomechanical differences, the improvement in outcome scores over time can be expected to be very similar. This study is helpful to patients and health-care providers to establish expectations regarding the rate of recovery after total shoulder arthroplasty. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Purpose: The intrawound application of lyophilized vancomycin has been reported to significantly decrease the rates of perioperative infection in arthroplasty and spine procedures. The local effect of clinically used supra-therapeutic concentration of intra wound vancomycin on surrounding healing tissue has been a topic of continued investigation. The purpose of this study was to examine the in vitro cytotoxicity profile of vancomycin hydrochloride on osteoblasts, fibroblast, and myoblasts. Methods: Human primary osteoblasts (Lonza), fibroblasts (Lonza), and myoblasts (DV Biologics) were expanded and passaged in sterile polystyrene tissue culture flasks and plated at a density of 10,000 cells/cm2. Cells were exposed to vancomycin hydrochloride (Sigma-Aldrich) at concentrations of 1, 3, 6, or 12 mg/cm2. To assess the effect of vancomycin on cell migration, a scratch assay was performed, in which a "scratch" was made in a cell monolayer following vancomycin exposure, and images were subsequently captured at regular intervals until cellular closure of the scratch. Cell survival was measured 48 hours post-vancomycin exposure using a cell cytotoxicity assay (Cell Counting Kit-8, Dojindo). Results: Vancomycin concentrations greater than or equal to 1 mg/cm2 decreased survival of myoblasts and osteoblasts to less than 11% relative to control. Vancomycin greater than or equal to 3 mg/ cm2 decreased fibroblast survival to less than 8% relative to control (Fig. 1). Vancomycin concentrations of 1 mg/cm2 did not significantly affect the survival of fibroblasts. Closure of the scratch defect was observed in less than 24 hours for all control conditions. In myoblasts and osteoblasts, the scratch defect remained open indefinitely following exposure to vancomycin concentrations greater than or equal to 1 mg/cm2. Closure of the scratch defect in fibroblasts was observed in less than 36 hours following exposure to vancomycin of 1 mg/cm2, and remained opened indefinitely following exposure to vancomycin greater than or equal to 3 mg/cm2. Conclusions: Vancomycin has a significant cytotoxic effect on proliferating osteoblasts and myoblasts at concentrations greater than (Figure Presented) or equal to 1 mg/cm2.Vancomycin has a pronounced cytotoxic effect on fibroblasts at concentrations greater than or equal to 3 mg/cm2. Further in vivo studies are warranted to investigate the effect of high local concentrations of vancomycin on infection, bony fusion, and wound healing

Introduction: While total shoulder arthroplasty (TSA) is generally associated with good to excellent outcomes in majority of patients, the integrity and the function of the subscapularis tendon may be compromised after the procedure and lead to inferior outcomes. Therefore, the efficacy of a subscapularis sparing TSA procedure was evaluated in a prospective, double blinded, randomized study. Methods: With IRB approval, patients with end stage osteoarthritis of the shoulder were enrolled into a prospective clinical trial from 2010 to 2014. These patients were randomized into two groups. Group 1 patients were treated with TSA using the subscapularis sparing surgical approach in which the prosthesis was inserted entirely through the rotator interval without violating the subscapularis tendon (SPARING). Group 2 patients were treated with TSA using the standard surgical approach with subscapularis tenotomy (STANDARD). Both the patient and the evaluators remained "blinded" to the surgical approach throughout the study period. Minimum 2 year outcome data was collected using the visual analog score (VAS) for pain and the American Shoulder and Elbow Surgeon (ASES) outcome score. Results: A total of 107 shoulders were enrolled (57 SPARING, 50 STANDARD). Of these, 14 TSA procedures could not be completed as initially randomized. In addition, 3 patients expired (unrelated to the procedure), 7 patients withdrew from the study, and 2 moved away. Of the remaining 81 patients, 2 year outcome data could not be collected from another 11. Thus, complete 2 year outcome data was collected from 32 SPARING and 38 STANDARD patients at an average follow up of 31.1 and 34.4 months, respectively. The ASES score and VAS for the SPARING group improved significantly from 29.3 +/- 12.5 and 6.6 +/- 2.1 to 82.6 +/- 18.8 and 1.6 +/- 2.2 (mean +/- standard deviation). Similarly, the ASES score and VAS for the STANDARD group also improved significantly from 32.8 +/- 16.1 and 6.3 +/- 2.4 to 87.1 +/- 14.5 and 1.0 +/- 1.7. In comparison to their pre-operative status, the ASES score for the SPARING and the STANDARD groups improved 53.9 +/- 22.3 and 54.0 +/- 18.7 points, respectively. The VAS for the SPARING and the STANDARD groups also improved 5.1 +/- 3.1 and 5.3 +/- 2.5 points, respectively. Neither of these differences between the SPARING and the STANDARD groups reached statistical significance. Complication profiles were similar in both groups with 3 in the SPARING group and 2 patients in the STANDARD group requiring revision surgery during the study period. Discussion: At a short term follow up, the outcome of TSA using the subscapularis sparing surgical approach was similar to that after TSA using the standard surgical approach. Future studies with longer follow up of these patients will be required to document the potential benefits of this surgical technique

Total hip arthroplasty has been utilized for the past 50 years as an effective treatment for degenerative, inflammatory and traumatic disorders of the hip. The design of these implants has generally followed the anatomy of the hip as a ball and socket joint with the femoral head representing the ball and the acetabulum representing the socket. We describe a novel hip arthroplasty design in which the "ball" is located on the acetabular side and the "socket" is located on the femoral side. The results of extensive biomechanical testing are described and document wear and corrosion characteristics that are at least equivalent to standard designs. These results support clinical assessment as the next step of the evaluation.