Qualitative and Quantitative Anatomy of the Deep Radioulnar Ligaments' Insertion on Ulna: Cadaveric, Histologic, and MRI Study.

PURPOSE: To qualitatively and quantitatively analyze the anatomic features of the insertion of deep radioulnar ligaments (RULs) and provide an anatomic basis for further studies. METHODS: The anatomic features of deep RUL insertion were observed macroscopically in 26 cadaveric wrists, after which the size of the deep RUL footprint and distance from the center of the footprint to the ulnar-sided margin of articular cartilage of the ulnar head were each measured. Five specimens were analyzed histologically to examine the attachment of the RUL on the ulna. In addition, we evaluated 21 asymptomatic wrists from healthy volunteers using 3.0 T magnetic resonance imaging. RESULTS: The insertion of the deep RUL was located mainly on the radial aspect of the ulnar fovea from the foveal center to the articular cartilage. The footprint of the deep RUL appeared in 3 different shapes. The maximal width, length, and area of the footprint of the deep RUL were 3.7 (95% confidence interval [CI], 3.3-4.0) mm, 8.4 (95% CI, 7.9-8.9) mm, and 26.3 (95% CI, 23.4-29.1) mm2, respectively. Histologic analyses showed the attachment of the deep RUL on the radial wall of the fovea exhibited a direct insertion with typical 4-layer structures. The deep RUL fibers formed an acute angle with the distal component of the triangular fibrocartilage complex. CONCLUSIONS: The deep RUL was inserted on the radial side of the ulnar fovea and not the foveal center; it had direct insertion on the radial wall continuous with articular cartilage, and the fibers in the direct insertion formed an acute angle with the distal component of the triangular fibrocartilage complex. CLINICAL RELEVANCE: Understanding the quantitative anatomy of the deep RUL insertion may help guide surgeons to perform an anatomic foveal repair of the triangular fibrocartilage complex in its native footprint.

Pharmacologic Thromboprophylaxis Other Than Aspirin Is Associated With Increased Risk for Procedural Intervention for Arthrofibrosis After Anterior Cruciate Ligament Reconstruction.

PURPOSE: To compare rates of procedural intervention for arthrofibrosis following anterior cruciate ligament reconstruction (ACLR) among patients who were not prescribed any pharmacologic thromboprophylaxis compared with patients who were prescribed aspirin and to patients who were prescribed other agents. METHODS: A search of a national insurance claims database was performed to identify all patients who underwent ACLR from 2007 to 2017 who were active within the database at a minimum of 6 months before and 18 months after their surgery. The primary outcome studied was a subsequent procedure for arthrofibrosis, manipulation under anesthesia, and lysis of adhesions (MUA/LOA). Patients who filled a prescription for aspirin, low-molecular weight heparin, direct factor Xa inhibitors, fondaparinux, and warfarin within 2 days after their surgery were included and those who filled a prescription within 3 months before surgery were excluded. Thromboprophylaxis status was defined as no thromboprophylaxis, aspirin, and any agent other than aspirin. Logistic regression analysis was performed to determine the association between prophylaxis status and MUA/LOA. RESULTS: Of the 14,081 patients in our final surgical population, 191 patients had MUA/LOA and 13,890 patients did not. In total, 499 patients were prescribed pharmacologic prophylaxis. Rates of MUA/LOA across groups were 1.3% in the group with no thromboprophylaxis, 1.9% in the group prescribed aspirin, and 4.3% in the group prescribed any agent other than aspirin. Only the group prescribed an agent other than aspirin was significantly associated with subsequent procedure for arthrofibrosis (odds ratio 2.6, 95% confidence interval 1.3-4.8, P = .004). CONCLUSIONS: Patients who were prescribed a pharmacologic agent other than aspirin had a 2.6 times greater likelihood of requiring a procedural intervention for arthrofibrosis following ACLR compared with patients who were not prescribed a thromboprophylaxis agent LEVEL OF EVIDENCE: III, Retrospective Cohort Study.

Chronic Preoperative Opioids Are Associated With Revision After Rotator Cuff Repair.

PURPOSE: We sought to clarify the relationship between chronic preoperative opioids and complications following rotator cuff repair. Specifically, we assessed revision, a definitive postoperative end point for surgical outcome. METHODS: This study used PearlDiver, a United States national insurance claims database. All patients undergoing rotator cuff repair from 2008 to 2018 were identified and stratified based on a minimum of 2 opioid prescriptions within the 6 months before surgery, with 1 prescription occurring within 0 to 3 months before surgery and a second prescription within 4 to 6 months before surgery. Univariate logistic regressions of risk factors were conducted, followed by multivariate analysis of comorbidities, including ongoing preoperative opioids, any preoperative nonsteroidal anti-inflammatory drug (NSAID) prescriptions, age, sex, diabetes, tobacco, and obesity. RESULTS: In total, 28,939 patients undergoing rotator cuff repair were identified, of whom 10,695 had opioid prescriptions within both 0 to 3 months and 4 to 6 months before index rotator cuff repair, whereas 18,244 had no opioid prescriptions within the 6-month preoperative period. In total, 977 (3.4%) patients underwent revision within 6 months, which increased to 1311 (4.5%) within 1 year of the index procedure. In the multivariate analysis controlling for age, preoperative NSAID prescriptions, tobacco, diabetes, obesity, and sex, we observed a significant association between chronic preoperative opioid prescriptions and rotator cuff repair revision (6-month odds ratio 1.12; P = .021, 1-year odds ratio 1.43; P < .001) following index procedure. CONCLUSIONS: We report increased rates of revision within both 6 months and 1 year in patients with prolonged preoperative opioid prescriptions. The opioid cohort had greater rates of preoperative NSAID use and tobacco use, which also were observed to be independent risk factors for revision at both timepoints. LEVEL OF EVIDENCE: III; Retrospective comparative study.

National Trends Show Declining Use of Arthroscopic Subacromial Decompression Without Rotator Cuff Repair.

PURPOSE: The goal of this study was to investigate trends in the United States for arthroscopic subacromial decompression (aSAD) and open SAD (oSAD) with and without rotator cuff repair (RCR) between 2010 and 2018. METHODS: The PearlDiver Mariner claims database was queried using CPT codes for open and arthroscopic subacromial decompression and rotator cuff repair. Patient cohorts were developed for those undergoing aSAD or oSAD between 2010 and 2018, then segmented by whether RCR was performed simultaneously. Annual incidence was analyzed, as were associated diagnosis codes, and concomitant shoulder-associated procedures performed on the same day. RESULTS: The PearlDiver Mariner dataset from 2010 to 2018 included 186,932 patients that underwent aSAD, while 9,263 patients underwent oSAD. The total incidence of aSAD declined from 118.0 to 71.3 per 100,000 (39.6% decrease) (P < .001). This change was due primarily to a decreasing incidence of aSAD performed without RCR, which declined from 66.3 to 25.5 per 100,000 (61.5% decrease) (P < .001). During the same period, the incidence of aSAD combined with RCR remained relatively stable, from 51.7 to 45.8 per 100,000 (11.5% decrease) (P = .27). The overall incidence of oSAD declined from 7.1 to 2.2 per 100,000 (68.1% decrease) (P < .001). CONCLUSIONS: The overall rate of aSAD has declined in recent years, primarily due to a large decrease in the incidence of aSAD without RCR as an isolated treatment for rotator cuff disorders. CLINICAL RELEVANCE: Prior studies have demonstrated a rising incidence of SAD; however, high-level clinical evidence and clinical practice guidelines have challenged its efficacy. It is important for orthopaedic surgeons to understand evolving national trends in management among their peers.

Preoperative lumbar epidural steroid injections administered within 6 weeks of microdiscectomy are associated with increased rates of reoperation.

PURPOSE: Lumbar epidural steroid injections (LESIs) are widely utilized for back pain. However, as studies report adverse effects from these injections, defining a safe interval for their use preoperatively is necessary. We investigated the effects of preoperative LESI timing on the rates of recurrent microdiscectomy. METHODS: This study utilized the PearlDiver national insurance claims database. Microdiscectomy patients were stratified by the timing of their most recent LESI prior to surgery into bimonthly cohorts (0-2 months, 2-4 months, 4-6 months). This first cohort was further stratified into biweekly cohorts (0-2 weeks, 2-4 weeks, 4-6 weeks, 6-8 weeks). The 6-month reoperation rate was assessed and compared between each injection cohort and a control group of patients with no injections within 6 months before surgery. Univariate analyses of reoperation were conducted followed by multivariate analyses controlling for risk factors where appropriate. RESULTS: A total of 12,786 microdiscectomy patients were identified; 1090 (8.52%) received injections within 6 months before surgery. We observed a significant increase in the 6-month reoperation rates in patients who received injections within 6 weeks prior to surgery (odds ratio [OR] 1.900, 1.218-2.963; p = 0.005) compared to control. No other significant differences were observed. DISCUSSION: In this study, microdiscectomy performed within 6 weeks following LESIs was associated with a higher risk of reoperation, while microdiscectomy performed more than 6 weeks from the most recent LESI demonstrated no such association with increased risk. Further research into the interaction between LESIs and recurrent disk herniation is necessary.

Trans-coracoacromial Ligament Glenohumeral Injection With Arthroscopic Confirmation.

PURPOSE: To arthroscopically evaluate the trans-coracoacromial ligament glenohumeral (GH) injection technique by understanding intra-articular needle-tip placement and potential misplacement and complications. METHODS: The technique relies on the palpation of 3 bony landmarks: anterolateral corner of the acromion, superolateral border of the coracoid tip, and curved depression of the distal clavicle. The skin entry site lies on the line connecting the curved depression of the distal clavicle and superolateral border of the coracoid tip, two-thirds of the way from the former and one-third of the way from the latter. The direction of the needle is perpendicular to the triangle formed by the 3 bony landmarks. The technique is used to insufflate the GH joint at the start of shoulder arthroscopy procedures with patients in the beach-chair position. Saline solution is injected, and the position of the needle tip in the GH joint is evaluated arthroscopically. An injection is considered successful if saline solution can be injected and the needle tip can be visualized intra-articularly. RESULTS: This study enrolled 195 patients undergoing shoulder arthroscopy. Successful needle placement in the GH joint occurred in 179 patients (91.8%); placement occurred through the rotator interval in 122 of these, adjacent or through the long head of the biceps tendon in 41, through the upper subscapularis or anterior supraspinatus in 13, and through the anterior labrum in 3. Regarding the 16 failures (8.2%), the needle position did not allow saline solution to be injected because of high resistance in 3 patients whereas the needle tip was not visualized in 13. The needle tip was presumed to rest within the subscapularis muscle or tendon or the labrum in 10 failed injections. CONCLUSIONS: The trans-coracoacromial ligament injection technique showed a high success rate (91.8%) in anesthetized patients about to undergo arthroscopy, whereas the failed injections mainly occurred because the needle was inserted into the subscapularis or labrum. This technique can be used for awake patients with different diagnoses in multiple settings. LEVEL OF EVIDENCE: Level IV, diagnostic study.

Coracoid morphology is not associated with subscapularis tears.

BACKGROUND: The observation of the roller-wringer effect fueled the idea that coracoid morphology is related to subscapularis pathology. We aimed to examine this relationship, specifically focusing on how the coracohumeral distance (CHD) and 2 new metrics of coracoid morphology relate to subscapularis tears. METHODS: In this retrospective study, we identified consecutive patients 45 years or older who underwent shoulder arthroscopy for any indication. We blindly reviewed preoperative magnetic resonance imaging studies of each patient, measuring the CHD, lateral extent (LE), and caudal extent (CE) of the coracoid process. Patients' subscapularis condition was assessed via operative reports; stratified according to Lafosse grade criteria; and compared for differences in the CHD, LE, and CE by 1-way analysis of variance and 2-tailed t tests. RESULTS: The study included 201 patients. Of these, 112 had no evidence of subscapularis injury, whereas Lafosse grade I injuries were identified in 52 patients; grade II, in 19; and grades III-V, in 18. The CHD, LE, and CE were not correlated with subscapularis injury (CHD, P = .36; LE, P = .36; and CE, P = .13). CONCLUSIONS: We found no correlation between subscapularis injury and the CHD, LE, and CE. These findings support the idea that coracoid morphology may not be a cause of subscapularis pathology and suggest that coracoplasty may not be necessary prophylactically or as part of subscapularis repair.

Nonoperative Management of Hip Labral Tears Yields Similar Total Hip Arthroplasty Conversion Rate to Arthroscopic Treatment.

BACKGROUND: Arthroscopic treatment of hip labral tears has increased significantly in recent years. There is limited evidence comparing nonoperative management to arthroscopic treatment. The purpose of this study is to evaluate the progression to total hip arthroplasty (THA), as well as the cost associated with arthroscopic management of labral tears compared to nonoperative treatment. METHODS: The Humana claims database was queried from 2007 through 2016. International Classification of Diseases and Current Procedural Terminology codes were used to identify patients with hip labral tears and hip arthroscopy and THA procedures. Two cohorts were created: a nonoperative group and an operative group. Following propensity score matching, the rate of conversion and time to THA conversion were calculated. Cost was calculated using the total cost reimbursed for encounters within 6 months. Continuous variables were analyzed using Student t-test and Mann-Whitney test, and categorical variables were analyzed using chi-square test. RESULTS: After propensity matching, 864 patients were included in the analysis. The conversion rate to THA in the operative group (6.7%) and the nonoperative group (5.3%) was not statistically different (P = .391). The operative group had a longer time to THA (21.5 ± 16.8 months) than the nonoperative group (15.9 ± 19.5 months; P = .044). The cost for the operative group was significantly higher ($14,266.55 ± $7187.96) compared to the nonoperative group ($2941.96 ± $2664.00; P < .001). CONCLUSION: This study did not find a difference in the rate of conversion to THA for operative vs nonoperative groups. Time to THA in the operative group was longer, however, at the expense of higher costs.

Orthopaedic Shoulder Surgery in the Ambulatory Surgical Center: Safety and Outcomes.

PURPOSE: To determine whether the risk of adverse events and readmission after non-arthroplasty shoulder surgery is influenced by the outpatient setting of surgical care and to identify risk factors associated with these adverse events. METHODS: The Humana Claims Database was queried for all patients undergoing arthroscopic shoulder surgery and related open procedures in the hospital-based outpatient department (HOPD) or ambulatory surgical center (ASC) setting, using the PearlDiver supercomputer. Arthroplasty procedures were excluded because they carry a risk profile different from that of other outpatient surgical procedures. Outcome variables included unanticipated admission after surgery, readmission, deep vein thrombosis, pulmonary embolism, and wound infection within 90 days of surgery. The ASC and HOPD cohorts were propensity score matched, and outcomes were compared between them. Finally, logistic regression models were created to identify risk factors associated with unplanned admission after surgery. RESULTS: A total of 84,658 patients met the inclusion criteria for the study: 28,730 in the ASC cohort and 56,819 in the HOPD cohort. The rates of all queried outcomes were greater in the HOPD cohort and achieved statistical significance. Sex, region, race, insurance status, comorbidity burden, anesthesia type, and procedural type were included in the regression analysis of unplanned admission. Factors associated with unplanned admission included increasing Charlson Comorbidity Index (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.12-1.17; P < .001); HOPD service location (OR, 2.37; 95% CI, 2.18-2.58; P < .001); general anesthesia (OR, 1.34; 95% CI, 1.08-1.59; P = .008); male sex (OR, 2.58; 95% CI, 2.17-3.15; P = .007); and open surgery (OR, 2.35; 95% CI, 1.90-2.61; P < .001). CONCLUSIONS: The lower rates of perioperative morbidity in the ASC cohort suggest that proper patient selection is taking place and lends reassurance to surgeons who are practicing or are considering practicing in an ASC. Patients to whom some or all the risk factors for unplanned admission apply (male sex, higher comorbidity burden, open surgery) may be more suitable for HOPDs because admission from an ASC can be difficult and potentially unsafe. LEVEL OF EVIDENCE: Level III, comparative study.

General health measures in shoulder surgery: are we powered for success?

BACKGROUND: Surgeons, policymakers, and payers increasingly use changes in general health to guide decision-making. It is unknown how such measures are incorporated into shoulder surgery research, how strongly they are associated with changes in shoulder-specific outcomes, and whether they are appropriately powered. METHODS: PubMed was searched for articles reporting shoulder-specific and general health measures after rotator cuff repair and total shoulder arthroplasty. Study characteristics, results at the study group level, reporting of power calculations, and statistical significance were recorded. Meta-regression was employed to describe the association of changes between shoulder-specific and general health measures. RESULTS: Of 360 identified abstracts, 21 articles with 28 patient groups were included. Only 1 article was published before 2000. There was a strong association of changes between shoulder-specific and general health measures (r = 0.66; P < .001). Power calculations were mentioned in 33% of studies and based on shoulder-specific measures. Of 20 studies conducting hypothesis tests, 75% reported agreement regarding the statistical significance of shoulder-specific and general health tests. Of 5 discordant studies, 4 found the shoulder-specific measure statistically significant and not the general health measure. CONCLUSION: Shoulder surgery research increasingly reports changes in general health measures that are associated with changes in shoulder-specific measures, suggesting that improvements in shoulder symptoms increase quality of life. When disagreement exists, it usually results from the general health measure's not meeting statistical significance, which may simply reflect type II error. Research reporting general health measures should carefully report power considerations to avoid misinterpretation of findings failing to reach statistical significance.

Preoperative corticosteroid joint injections within 2 weeks of shoulder arthroscopies increase postoperative infection risk.

BACKGROUND: There is currently no consensus regarding the safe timing interval between corticosteroid shoulder injections and future shoulder arthroscopies. Our study assessed the relationship between preoperative corticosteroid injection timing and shoulder arthroscopy infectious outcomes. METHODS: We used an insurance database to identify and sort all shoulder arthroscopy patients by corticosteroid shoulder injection history within 6 months before surgery. Patients who received injections were stratified by the timing of their most recent preoperative injection. The overall infection rate and rate of severe infections requiring treatment through intravenous antibiotics or surgical débridement in the 6-month postoperative period were compared using χ2 tests between the injection cohorts and a control group of patients defined as those with no injection history. RESULTS: We identified 50,478 shoulder arthroscopy patients, of whom 4115 received injections in the 6-month preoperative period. We found a significant increase in both the overall infection rate (P < .0001) and severe infection rate (P < .0001) in patients who received injections within 2 weeks before surgery (n = 79; 8.86% and 6.33%, respectively) compared with those who received no injections in the 6-month preoperative period (n = 46,363; 1.56% and 0.55%, respectively). No other significant differences were observed. CONCLUSIONS: Our results suggest that in patients who have received corticosteroid injections, shoulder arthroscopic procedures may be safely performed after at least 2 weeks has passed since the most recent injection to minimize the risk of postoperative infection. In addition, procedures performed within 2 weeks of an injection may increase the risk of postoperative infection.

Benchmarks of Duration and Magnitude of Opioid Consumption After Total Hip and Knee Arthroplasty: A Database Analysis of 69,368 Patients.

BACKGROUND: Opioid prescribing after orthopedic surgeries varies widely, and there is little consensus establishing proper standards of care. This retrospective cohort study examines opioid prescribing trends following total hip (THA) and knee (TKA) arthroplasty and evaluates preoperative opioid use as a predictor of duration and magnitude of postoperative opioid use. METHODS: Patients who underwent THA or TKA in a nationwide insurance database were stratified by preoperative opioid use. Naive, sporadic, and chronic users were defined as 0, 1, or 2+ prescriptions filled 6 months before surgery. Patients were excluded for readmission or subsequent surgery. Duration of opioid use was defined as time between the procedure and the last opioid prescription record, and magnitude of opioid use was defined as quantity of pills filled by 30 days postop. RESULTS: Naive patients were less likely than chronic users to fill any opioid prescription after surgery (THA: 61.5% naive vs 90.4% chronic, TKA: 72.0% naive vs 95.9% chronic), and they obtained fewer pills (THA: 73 pills naive vs 126 pills chronic, TKA: 86 pills naive vs 126 pills chronic, 5-mg oxycodone equivalent). Between 10% (THA) and 13% (TKA) of naive and between 47% (THA) and 62% (TKA) of chronic users continued opioid use at 1 year postop. CONCLUSION: Chronic users obtain more opioids postoperatively and continue filling prescriptions for longer than naive patients. This work benchmarks norms regarding opioid use and furthermore these data highlight the powerful effect of opioid exposure during surgery as 10%-13% of naive patients continued opioids at 1 year postop.

Transcoracoacromial Ligament Glenohumeral Injection Technique: Accuracy of 116 Injections in Idiopathic Adhesive Capsulitis.

PURPOSE: To describe a transcoracoacromial ligament glenohumeral injection technique that does not require radiographic guidance and to explore the accuracy of this injection technique in patients with idiopathic adhesive capsulitis. METHODS: From February 2015 to April 2017, 89 consecutive patients (116 injections) with idiopathic adhesive capsulitis were included in the study. All of them received unguided glenohumeral injection via the transcoracoacromial ligament technique, and postprocedural fluoroscopic images were used to determine accuracy. The anterolateral corner of acromion, the superior lateral border of coracoid tip, and the curved depression of distal clavicle were identified. The needle entry site was located at the trisection point between the distal third and middle third of the superior lateral border of coracoid tip-curved depression of the distal clavicle line; needle trajectory was perpendicular to the plane formed by the 3 points, and the needle was advanced toward the humeral head. An injection was rated a success if the first fluoroscopic picture showed intra-articular contrast; it was rated a failure if contrast was not intra-articular or the needle needed to be redirected more than 2 times. RESULTS: Out of 116 injections, 111 (95.7%) were successful. For 5 failed injections, there was 1 shoulder with more than 3 redirections and 4 shoulders with no intra-articular contrast (the needle hit the coracoid process in 1 shoulder, the needle rested in the anterior glenoid labrum in 2 shoulders, and the needle was inserted into the subscapularis in 1 shoulder). CONCLUSIONS: The transcoracoacromial ligament glenohumeral injection technique is highly accurate and reproducible in patients with idiopathic adhesive capsulitis. LEVEL OF EVIDENCE: Level IV, therapeutic retrospective case series.

Time to Dislocation Analysis of Lumbar Spine Fusion Following Total Hip Arthroplasty: Breaking Up a Happy Home.

BACKGROUND: Although a history of lumbar spine fusion (LSF) is associated with increased dislocation risk following total hip arthroplasty (THA), the effect of LSF following THA is not well described. This study sought to describe the dislocation-free survival experience of patients with THA undergoing LSF, compare this to similar patients not undergoing LSF, and assess factors associated with dislocation risk following LSF. METHODS: Center for Medicare Service billing data from 2005 to 2014 was analyzed utilizing the PearlDiver platform. Patients without evidence of hip instability, defined as no dislocation event within at least 6 months following THA, were identified and stratified by having subsequent LSF. Kaplan-Meier curves were used to describe dislocation-free survival of these groups and assess factors associated with dislocation. RESULTS: Among 17,223 patients without history of hip instability following THA, there was no spike in dislocations following LSF with patients having a persistent and stable rate of dislocation of 0.7% per year. This experience was of similar shape but increased hazard when compared to that of 863,182 patients not undergoing LSF who had a dislocation rate of 0.4% per year (P < .001). Dislocations were not strongly associated with gender, age, comorbidities, or fusion length. CONCLUSION: Patients without evidence of hip instability following THA subsequently undergoing LSF do not have a spike in dislocations in the perioperative period but do assume a persistently elevated risk of dislocation. Future research should identify factors responsible for this increased risk to determine whether they may be modifiable.

A Novel Organ Culture Model of Mouse Intervertebral Disc Tissues.

The intervertebral disc (IVD) is a fibrocartilaginous joint between two vertebral bodies. An IVD unit consists of a gelatinous central nucleus pulposus, encased by the annulus fibrosus, which is sandwiched between cartilaginous endplates (EPs). The IVD homeostasis can be disrupted by injuries, ageing and/or genetic predispositions, leading to degenerative disc disorders and subsequent lower back pain. The complex structure and distinct characteristics of IVDs warrant the establishment of robust in vitro IVD organ culture for studying the etiology and treatment of disc degeneration. Here, we isolate mouse lumbar IVDs and culture the minimal IVD units in submersion or suspension medium supplemented with 2% bovine serum or 10% fetal bovine serum (FBS). We find the minimal IVD units remain healthy for up to 14 days when cultured in submersion culture supplemented with 10% FBS. New bone formation in the EPs of the cultured IVDs can be assessed with calcein labeling. Furthermore, the cultured IVDs can be effectively transduced by recombinant adenovirus, and transgene expression lasts for 2 weeks. Thus, our findings demonstrate that the optimized IVD organ culture system can be used to study IVD biology and screen for biological factors that may prevent, alleviate and/or treat disc degeneration.

The Prodomain-Containing BMP9 Produced from a Stable Line Effectively Regulates the Differentiation of Mesenchymal Stem Cells.

BACKGROUND: BMPs play important roles in regulating stem cell proliferation and differentiation. Using adenovirus-mediated expression of the 14 types of BMPs we demonstrated that BMP9 is one of the most potent BMPs in inducing osteogenic differentiation of mesenchymal stem cells (MSCs), which was undetected in the early studies using recombinant BMP9 proteins. Endogenous BMPs are expressed as a precursor protein that contains an N-terminal signal peptide, a prodomain and a C-terminal mature peptide. Most commercially available recombinant BMP9 proteins are purified from the cells expressing the mature peptide. It is unclear how effectively these recombinant BMP9 proteins functionally recapitulate endogenous BMP9. METHODS: A stable cell line expressing the full coding region of mouse BMP9 was established in HEK-293 cells by using the piggyBac transposon system. The biological activities and stability of the conditioned medium generated from the stable line were analyzed. RESULTS: The stable HEK-293 line expresses a high level of mouse BMP9. BMP9 conditioned medium (BMP9-cm) was shown to effectively induce osteogenic differentiation of MSCs, to activate BMP-R specific Smad signaling, and to up-regulate downstream target genes in MSCs. The biological activity of BMP9-cm is at least comparable with that induced by AdBMP9 in vitro. Furthermore, BMP9-cm exhibits an excellent stability profile as its biological activity is not affected by long-term storage at -80ºC, repeated thawing cycles, and extended storage at 4ºC. CONCLUSIONS: We have established a producer line that stably expresses a high level of active BMP9 protein. Such producer line should be a valuable resource for generating biologically active BMP9 protein for studying BMP9 signaling mechanism and functions.

Obesity is Not Associated with Increased Short-term Complications After Primary Total Shoulder Arthroplasty.

BACKGROUND: Few studies have analyzed the association between elevated BMI and complications after total shoulder arthroplasty (TSA). Previous studies have not consistently arrived at the same conclusion regarding whether obesity is associated with a greater number of postoperative complications. We used a national surgical database to compare the 30-day complication profile and hospitalization outcomes after primary TSA among patients in different BMI categories. QUESTIONS/PURPOSES: We asked: (1) Is obesity associated with an increased risk of complications within 30 days of primary TSA? (2) Is obesity associated with increased operative time? METHODS: The American College of Surgeons National Surgical Quality Improvement Program(®) database for 2006 to 2012 was queried to identify all patients who underwent a primary TSA for osteoarthritis of the shoulder. The ACS-NSQIP(®) database was selected for this study as it is a nationally representative database that provides prospectively collected perioperative data and a comprehensive patient medical profile. Exclusion criteria included revision TSA, infection, tumor, or fracture. We analyzed 4796 patients who underwent a primary TSA for osteoarthritis of the shoulder. Patients who underwent a TSA were divided in four BMI categories: normal (18.5-25 kg/m(2)), overweight (25-30 kg/m(2)), obesity Class 1 (30-35 kg/m(2)), and obesity Class 2 or greater (> 35 kg/m(2)). Perioperative hospitalization data and 30-day postoperative complications were compared among different BMI classes. Differences in patient demographics, preoperative laboratory values, and preexisting patient comorbidities also were analyzed among different BMI groups, and multivariate analysis was used to adjust for any potential confounding variables. RESULTS: There was no association between BMI and 30-day complications after surgery (normal as reference, overweight group relative risk: 0.57 [95% CI, 0.30-1.06], p = 0.076; obesity Class 1 relative risk: 0.52 [95% CI, 0.26-1.03], p = 0.061; obesity Class 2 or greater relative risk: 0.54 [95% CI, 0.25-1.17], p = 0.117). However, greater BMI was associated with longer surgical times (for normal BMI control group: 110 minutes, SD, 42 minutes; overweight group: 115 minutes, SD, 46 minutes, mean difference to control: 5 minutes [95% CI, -1 to 10 minutes], p = 0.096; obesity Class 1: 120 minutes, SD, 43 minutes, mean difference: 10 minutes [95% CI, 5-15 minutes], p < 0.001; obesity Class 2 or greater: 122 minutes, SD, 45 minutes, mean difference: 12 minutes [95% CI, 6-18 minutes], p < 0.001). CONCLUSIONS: Although the surgical time increased for patients with greater BMI, the 30-day complications and perioperative hospitalization data after TSA were not different in patients with increased BMI levels. Obesity alone should not be a contraindication for TSA, and obese patients can expect similar incidences of postoperative complications. The preoperative medical optimization plan should be consistent with that of patients who are not obese who undergo TSA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Latissimus Dorsi and Teres Major Transfer With Reverse Shoulder Arthroplasty Restores Active Motion and Reduces Pain for Posterosuperior Cuff Dysfunction.

BACKGROUND: In patients with rotator cuff dysfunction, reverse shoulder arthroplasty can restore active forward flexion, but it does not provide a solution for the lack of active external rotation because of infraspinatus and the teres minor dysfunction. A modified L'Episcopo procedure can be performed in the same setting wherein the latissimus dorsi and teres major tendons are transferred to the lateral aspect of proximal humerus in an attempt to restore active external rotation. QUESTIONS/PURPOSES: (1) Do latissimus dorsi and teres major tendon transfers with reverse shoulder arthroplasty improve external rotation function in patients with posterosuperior rotator cuff dysfunction? (2) Do patients experience less pain and have improved outcome scores after surgery? (3) What are the complications associated with reverse shoulder arthroplasty with latissimus dorsi and teres major transfer? METHODS: Between 2007 and 2010, we treated all patients undergoing shoulder arthroplasty who had a profound external rotation lag sign and advanced fatty degeneration of the posterosuperior rotator cuff (infraspinatus plus teres minor) with this approach. A total of 21 patients (mean age 66 years; range, 58-82 years) were treated this way and followed for a minimum of 2 years (range, 26-81 months); none was lost to followup, and all have been seen in the last 5 years. We compared pre- and postoperative ranges of motion, pain, and functional status; scores were drawn from chart review. We also categorized major and minor complications. RESULTS: Active forward flexion improved from 56° ± 36° to 120° ± 38° (mean difference: 64° [95% confidence interval {CI}, 45°-83°], p < 0.001). Active external rotation with the arm adducted improved from 6° ± 16° to 38° ± 14° (mean difference: 30° [95% CI, 21°-39°], p < 0.001); active external rotation with the arm abducted improved from 19° ± 25° to 74° ± 22° (mean difference: 44° [95% CI, 22°-65°], p < 0.001). Pain visual analog score improved from 8.4 ± 2.3 to 1.7 ± 2.1 (mean difference: -6.9 [95% CI, -8.7 to -5.2], p < 0.001), and Single Assessment Numeric Evaluation score improved from 28% ± 21% to 80% ± 24% (mean difference: 46% [95% CI, 28%-64%], p < 0.001). There were six major complications, five of which were treated operatively. Overall, three patients' latissimus and teres major transfer failed based on persistent lack of external rotation. CONCLUSIONS: In patients with posterior and superior cuff deficiency, reverse shoulder arthroplasty combined with latissimus dorsi and teres major transfer through a single deltopectoral incision can reliably increase active forward flexion and external rotation. Patients experience pain relief and functional improvement but have a high rate of complications; therefore, we recommend the procedure be limited to patients indicated for reverse who have profound external rotation loss and a high grade of infraspinatus/teres minor fatty atrophy. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Accuracy of long head of the biceps subluxation as a predictor for subscapularis tears.

PURPOSE: The aim of this study is to understand the relation between long head of the biceps tendon (LHBT) subluxation and full-thickness tears of the subscapularis. METHODS: Magnetic resonance imaging (MRI) scans of 94 patients undergoing shoulder arthroscopy were evaluated preoperatively for the presence or absence of LHBT subluxation. Intraoperative pathology of the biceps and subscapularis tendons was recorded. The diagnostic accuracy of LHBT subluxation on preoperative MRI in determining full-thickness subscapularis tendon tears was calculated. RESULTS: Of the 94 patients in this study, 26 were diagnosed with LHBT subluxation preoperatively. Of these 26 patients, 9 were confirmed to have full-thickness tears of the subscapularis tendon (Lafosse grade 2 or higher). Of the remaining 68 patients who did not appear to have LHBT subluxation preoperatively, 2 were confirmed to have full-thickness tears of the subscapularis tendon. Thus LHBT subluxation on MRI as a predictor for full-thickness subscapularis tears had a sensitivity of 82%, specificity of 80%, positive predictive value of 35%, and negative predictive value of 97%. LHBT subluxation was directly correlated with the severity of the subscapularis tendon tear (P < .001). CONCLUSIONS: The diagnostic value of subluxation of the LHBT, as seen on an axial MRI scan, lies primarily in its negative predictive value. If the LHBT is not subluxated, it is unlikely that a full-thickness tear of the subscapularis tendon is present. Surgeons should be cautious about relying on biceps subluxation as a primary diagnostic tool in predicting subscapularis tears. LEVEL OF EVIDENCE: Level IV, study of diagnostic test.

Failure of the lesser tuberosity osteotomy after total shoulder arthroplasty.

BACKGROUND: Lesser tuberosity osteotomy (LTO) as an approach during total shoulder arthroplasty (TSA) is a reliable technique with strong biomechanical fixation and a low failure rate. Complications have been infrequently reported in the literature. METHODS: We report a case series of 5 patients who sustained failure of the LTO repair after primary TSA. The data on the patient demographic characteristics, surgical technique, postoperative care, revision surgery, and clinical outcomes are reported. RESULTS: The mean age of the 5 patients was 52 years, all patients were men, and the mean body mass index was 28 kg/m(2). They were followed up for a mean of 29 months (range, 24-38 months). The mean time from initial TSA to diagnosis of LTO failure was 9 weeks (range, 5-12 weeks). Two patients reported no trauma, 2 had minor trauma (using a pulley, rolling over in bed), and 1 sustained a fall. At the latest follow-up, the mean visual analog scale; Single Assessment Numeric Evaluation; University of California, Los Angeles; and American Shoulder and Elbow Surgeons scores were 4 (range, 0-6), 48 (range, 20-70), 19 (range, 11-22), and 63 (range, 48-83), respectively. Only 1 patient required no additional procedures beyond the revision LTO repair. Another patient required a second revision LTO repair. The remaining 3 patients either underwent or were recommended to undergo reverse arthroplasty. CONCLUSION: Failure of the LTO repair after TSA may possibly be an under-reported complication that is associated with poor clinical outcomes and limited options for revision surgery. In patients with a high risk of LTO failure, considerations should be made to augment the LTO repair during the index TSA procedure.