Faculty Bibliography

BACKGROUND:We sought to identify the influence of shoulder arthroplasty (SA) type (primary anatomic, primary reverse, revision) and indication (fracture, arthritis) on the risk of postoperative packed red blood cell transfusion (pRBCT) and intravenous fluid bolus (IVFB). METHODS:Patients who underwent SA from 2013 through 2016 at our institution were categorized into four groups: primary anatomic (pTSA; N = 298), primary reverse (pRTSA; N = 292), revision (RevSA; N = 133), and shoulder arthroplasty for fracture (SAF; N = 58). Basic demographics, intraoperative metrics, preoperative lab values, and postoperative interventions (pRBCT and IVFB) were retrieved from electronic records. RESULTS:There were 781 SAs, of which 176 cases involved at least one postoperative intervention: pRBCT (6.3%) or IVFB (18.8%). Compared to pTSA, the odds of pRBCT in pRTSA, revSA, and SAF were: 3.0 (95% CI 0.9-10.0), 3.4 (95% CI 0.9-2.7), and 8.6 (95% CI 2.2-32.9), respectively. Independent risk factors for pRBCT included increasing age (p = 0.003), underweight body mass index (p = 0.019), Charlson Comorbidity Index ≥ 3 (p = 0.002), inpatient discharge to higher level of care (p = 0.011), estimated blood loss (p = 0.003), and preoperative hemoglobin (p ≤ 0.001). Also, compared to pTSA, the odds for IVFB in pRTSA, revSA, and SAF were: 2.8 (95% CI 1.7-4.6), 2.2 (95% CI 1.2-4.0), and 4.7 (95% CI 2.2-9.9), respectively. Other independent risk factors for IVFB included female sex (0.002), CCI ≥ 3 (p = 0.017), and operative time (p = 0.047). CONCLUSION/CONCLUSIONS:Shoulder arthroplasty for fracture is an independent risk factor for higher risk of postoperative pRBCT and IVFB.

OBJECTIVE:The purpose of this study is to quantify the clinical and radiographic outcomes of patients with severe posterior glenoid wear who were treated with reverse total shoulder arthroplasty (rTSA) and a posterior augmented baseplate. METHODS:A total of 67 primary rTSA patients with osteoarthritis and posterior glenoid wear were treated with an 8° posterior augmented glenoid baseplate. All patients had a Walch B2, B3, or C glenoid, 2-year minimum follow-up, and mean follow-up of 40 months. All patients were scored preoperatively and at the latest follow-up using 5 clinical outcome metrics; active range of motion was also measured. A Student's 2-tailed, unpaired t-test quantified differences in outcomes, where P < .05 denoted significance. RESULTS:All patients experienced significant improvements in pain and function after primary rTSA with a posterior augmented glenoid baseplate. Three complications were reported for a rate of 4.5%; no cases of aseptic glenoid loosening occurred. A total of 90% of patients exceeded the minimal clinically important difference threshold, and 80% of patients exceeded the substantial clinical benefit threshold for each clinical outcome metric and range of motion measure. No differences in outcomes or complications were observed between Walch B2 and B3 patients, demonstrating that this full-wedge posterior augmented baseplate was equally good in each type of glenoid deformity. DISCUSSION/CONCLUSIONS:Primary rTSA patients with Walch B2, B3, and C glenoids who received an 8° posterior augmented glenoid baseplate experienced excellent clinical and radiographic outcomes with a low complication rate and no reports of aseptic glenoid loosening at a mean follow-up of 40 months.

BACKGROUND:Rotator cuff tendon tears are typically degenerative and usually affect the region of tendon insertion on bone. The remnant torn tendon is degenerative and may not be an ideal source for progenitor cells for cell-based therapies. Therefore, the aim of this study was to determine if musculotendinous junction (MTJ), which is adjacent to tendon would be a viable alternate source of progenitor stem cells. We also sought to study the gene expression profile MTJ progenitors and compare it with progenitors isolated from RC tendon, RC muscle and other existing tissue sources (bone marrow, adipose tissue, and Achilles tendon). METHODS:Rotator cuff tendon (RCT), muscle (RCM), and RCMTJ as well as Achilles tendon (AT) tissues were harvested from healthy male Lewis rats and progenitor cultures were established from these tissues and also from bone marrow and adipose tissue. Quantitative RT-PCR was performed on RNA extracts from intact tissues and progenitor cells using a custom array for the mesenchymal stem cell (MSC) differentiation marker genes. The gene expression profile of MSC differentiation markers within four tissues types, six progenitor cells, and between tissue and their corresponding progenitors were compared. RESULTS:Progenitors cells can be isolated from rat rotator cuff musculotendinous tissue and their pattern of MSC gene expression was similar to the rotator cuff tendon progenitors for majority of the genes tested. However, there were significant differences between the MSC gene expression patterns of RCMTJ and RCM progenitors. Furthermore, there were differences in gene expression between the RCMTJ tissue and its progenitor cells with respect to MSC differentiation markers. The gene expression pattern of RCMTJ tissue was similar to RCM tissue with respect to markers of chondrogenesis, myogenesis, tenogenesis, and MSC specific markers. CONCLUSION/CONCLUSIONS:We demonstrate that the musculotendinous junction contains distinct set of progenitor cells and their MSC gene expression pattern is similar to rotator cuff tendon progenitors. RCMTJ progenitors will be an attractive option for cell-based regenerative treatment of chronic rotator cuff tears.

BACKGROUND:The aims of this study were to examine variances in inpatient opioid consumption after total shoulder arthroplasty (TSA) and to determine factors influencing inpatient opioid utilization. METHODS:The sample included patients undergoing elective TSA at a tertiary-level institution between January 2016 and April 2018. Opioid consumption during the inpatient stay was converted into morphine milligram equivalents (MMEs), accounting for dosage and route of administration. The MMEs were calculated per patient encounter and used to calculate mean opioid consumption. Bivariate linear regression analysis was performed to assess the impact of patient-related factors and surgery-related factors on inpatient opioid consumption. RESULTS:Altogether 20 surgeons performed 622 TSAs. The average opioid dose per encounter was 47.4 ± 65.7 MME/d. MMEs prescribed varied significantly among surgeon providers (P < .01). Pre-existing psychiatric disorders (P = .00012), preoperative opioid use (P = .0013), highest quartile of median household income (P = .048), current-smoker status (P < .001), age < 60 years (P < .01), and general anesthesia (vs. regional anesthesia, P = .005) were associated with significant inpatient opioid consumption after TSA. Sex, race, American Society of Anesthesiologists status, replacement type (anatomic TSA vs. reverse TSA), and prior shoulder surgery did not show any significant differences. CONCLUSION/CONCLUSIONS:There is considerable variation in inpatient opioid consumption after TSA at the same institution. Knowledge of modifiable and nonmodifiable risk factors that increase inpatient opioid consumption will help to optimize multimodal analgesia protocols for TSA.

Introduction: There is no current standard by which culture specimens from revision shoulder arthroplasty should be handled, processed, cultured, and reported. Due to the relatively low numbers of cases multicenter study may provide information to form consensus recommendations. However, assimilation of multicenter data requires comparable methodologies. The objective of this study was to document and evaluate the extent of variability between surgeons and institutions. Methods: An 11-question survey was sent to 20 shoulder surgeons as part of the American Shoulder and Elbow Surgeons Periprosthetic Joint Infection Multicenter Workgroup. Questions addressed how samples are handled in the operating room by surgeons, processing of tissue samples and explants by laboratories, number of media, culture incubation durations, and culture reporting. Results: Common practices regarding specimen handling and processing were identified including prolonged culture incubation times >13 days (94% of participants). However, substantial variation in handling of tissue and explant specimens, number and type of media used, and reporting of results were identified. The majority of surgeons reported using a sterile instrument to harvest each individual tissue specimen (10/17, 59%), more so than using any available instrument (4/17, 24%) or washing and re-using the same instrument (3/17, 18%). Half of the institutions require a time limit by which samples must be processed in the laboratory (8/16, 50%). Nine institutions (9/16, 56%) report cultures in a semiquantitative manner, while 7 (44%) report cultures in a binary fashion. Five institutions reported having performed a negative control study, and the rate of positive cultures ranged between 0% and 17%. The majority of positive cultures from the negative controls contained Cutibacterium (92%). Discussion: Specimen handling, processing, culturing, and reporting varies widely between institutions. Due to the risk of false positives as demonstrated by negative control studies, surgeons should be cognizant of potential sources of contamination at the specimen handling level in the operating room and specimen processing level in the laboratory. Given the challenges in interpretation of positive cultures in revision shoulder arthroplasty, further studies are needed to determine whether assimilation of data across institutions is acceptable or whether a standard culturing methodology across institutions is necessary. Level of Evidence: V

The glenoid is considered a weak link in total shoulder arthroplasty because failure on the glenoid side is one of the most common reasons for revision of total shoulder arthroplasty. Glenoid wear is commonly seen in glenohumeral arthritis and compromises glenoid bone stock and also alters the native version and inclination of the glenoid. It is critical to recognize glenoid wear and correct it intraoperatively to avoid component malposition, which can negatively affect the survivorship of the glenoid implant. The end point of correction for the glenoid wear in shoulder arthroplasty is controversial, but anatomic glenoid component positioning is likely to improve long-term survivorship of the total shoulder arthroplasty. Preoperative three-dimensional (3-D) computer planning software, based on CT, is commercially available. It allows the surgeon to plan implant type (anatomic versus reverse), size, and position on the glenoid, and also allows for templating deformity correction using bone graft and/or augments. Guidance technology in the form of computer-assisted surgery (CAS) and patient-specific instrumentation (PSI) allows the surgeon to execute the preoperative plan during surgery with a greater degree of accuracy and precision and has shown superiority to standard instrumentation. However, the proposed benefits of this technology including improved glenoid survivorship, reduced revision arthroplasty rate and cost-effectiveness have not yet been demonstrated clinically. In this review, we present the current evidence regarding PSI and CAS in managing glenoid deformity in total shoulder arthroplasty.

BACKGROUND:Nonsteroidal anti-inflammatory drugs (NSAIDs) are being increasingly employed as a part of multimodal non-opioid strategies to treat postoperative pain. In the present study, we sought to review the effects of short-term NSAID use on musculoskeletal soft-tissue healing. METHODS:We performed a scoping review of all studies that included the use of NSAIDs and their effect on healing of soft tissues, which for the purpose of this review refers to non-osseous musculoskeletal tissue such as ligament, tendon, labrum, and meniscus. The inclusion criteria encompassed all studies (human, animal, and in vitro) that evaluated the effect of NSAIDs on soft-tissue healing. Subgroup analyses, wherever applicable, were conducted on the basis of the type of NSAID (cyclooxygenase [COX]-specific or nonspecific) and the type of study (human, animal, or in vitro). Relevant metadata from each study were abstracted, and descriptive statistics were used to summarize the results. RESULTS:A total of 44 studies met the inclusion criteria, including 3 human studies, 33 animal studies, and 8 in vitro studies. These studies included 4 different NSAIDs in the human subgroup, 16 different NSAIDs in the animal subgroup, and 7 different NSAIDs in the in vitro subgroup. The majority of reported studies (including 1 of 2 human studies, 10 of 14 animal studies, and 3 of 3 in vitro studies) demonstrated that COX-2-selective inhibitors had negative impact on soft-tissue healing. In contrast, the majority of human and animal studies (2 of 2 and 19 of 30, respectively) demonstrated that nonselective COX inhibitors had no negative effect on the healing of labrum, tendons, and ligaments. The majority of in vitro studies demonstrated that NSAIDs have a harmful effect on biological processes involved in tendon-healing and regeneration (tenocyte proliferation, collagen and glycosaminoglycan synthesis). CONCLUSIONS:Current limited evidence demonstrates that selective COX-2 inhibitors can negatively affect healing of musculoskeletal soft tissue after surgical repair. In contrast, the majority of studies demonstrate that nonselective COX inhibitors have no negative effect on musculoskeletal soft-tissue healing. Additional high-quality human clinical trials are necessary to provide more definitive conclusions.

INTRODUCTION/BACKGROUND:Management of the subscapularis during shoulder arthroplasty is controversial. The purpose of this study was to compare the biomechanical performance of subscapularis peel (SP) and lesser tuberosity osteotomy (LTO) in a cadaveric model. METHODS:The subscapularis and proximal humerus were dissected from all soft tissues in 21 fresh-frozen human cadaveric shoulders and randomized to undergo SP, LTO, or standard subscapularis tenotomy (ST, control). For SP and LTO, six #5 sutures were passed through eyelets in the implant (on lateral border and through drill holes in bicipital groove [2] and under trunion [4]). Double-row repair was performed using two lateral row transosseous sutures and four medial row sutures through the tendon (SP) or osseotendinous junction (LTO). Biomechanical properties and mode of failure were tested. RESULTS:There were no significant differences in elongation amplitude, cyclic elongation, or maximum load to failure between the three groups (P > 0.05). Mean stiffness was significantly higher in LTO (P = 0.009 vs. SP and ST). In the ST group, 7/7 specimens failed at the tendon-suture interface. For SP, 4/7 failed at the tendon-suture interface, one at the suture-bone interface, one fractured around the implant stem, and one at the knots. For LTO, 3/7 failed at the tendon-suture interface, two at the suture-bone interface and two fractured around the implant stem. CONCLUSIONS:In this cadaveric model, subscapularis repair via ST, SP, and LTO techniques was biomechanically equivalent. Additional studies are needed to confirm these findings and determine the influence of biologic healing on healing rates and clinical outcomes. LEVEL OF EVIDENCE/METHODS:N/a, biomechanical laboratory study.