Glenoid Structural Bone Grafting in Reverse Total Shoulder Arthroplasty: Clinical and Radiographic Outcomes.

INTRODUCTION: Current options for reconstruction of large glenoid defects in reverse total shoulder arthroplasty (RTSA) include structural bone grafting, utilization of augmented components, or 3D printed custom implants. Given the paucity in the literature on structural bone grafts in RTSA, this study reflects our experience on clinical and radiographic outcomes of structural bone grafts utilized for glenoid defects in RTSA. METHODS: We identified 33 consecutive patients who underwent RTSA utilizing structural bone grafts for glenoid bone loss between 2008 and 2019. Twenty-six patients with mean clinical follow-up of 4.4 ± 3.9 years and mean radiographic follow-up of 2.7 ± 3.2 years were included. Patient demographic data, peri-operative functional outcomes, radiographic outcomes, complications, and re-operation rates were determined. RESULTS: Between 2008 and 2019, 26 RTSAs were performed utilizing structural autograft or allograft for glenoid defects. There were 20 females (77%) and 6 males (23%), with mean presenting age of 68 years (range 41-86), mean BMI of 29 (range 21-44) and mean Charlson Comorbidity Index of 3 (range 0-8). There were 19 cases of central glenoid defects, and 7 were combined central and peripheral defects. Structural grafts included humeral head autograft (7), proximal humerus autograft (7), iliac crest autograft (7), distal clavicle autograft (2), and femoral head allograft (3). All eighteen revision RTSA cases had simultaneous humeral-sided revision. There was significant postoperative improvement in ASES scores (27.0 ± 12.6 preop vs. 59.8 ± 24.1 postop; p<0.001) and VAS scores (8.1 ± 3.6 preop vs. 3.0 ± 3.2 postop; p<0.001). Range of motion improved significantly for active forward elevation (63 ± 36º preop vs. 104 ± 36º postop; p<0.001) and external rotation (21 ± 20º preop vs. 32 ± 23º postop, p=0.036). Eighty-eight percent (23/26) of cases had successful reconstruction of the glenoid, defined as no visible radiolucent lines nor glenoid component migration at final follow-up. Re-operation rate was 19% (5/26) Postoperative complications included 2 cases of acromial stress fractures that were treated non-operatively, for a total complication rate (including re-operation) of 27% (7/26 cases). CONCLUSIONS: The use of structural bone autografts and allografts in RTSA was associated with improved outcome scores and range of motion. A reoperation rate of 19% and total complication rate of 27% were reported for these challenging cases. However, 86% of these complications were not related to structural glenoid reconstruction failure. Structural grafts are a reasonable option for glenoid reconstruction in RTSA cases with glenoid bone loss.

Continuous interscalene versus phrenic nerve-sparing high-thoracic erector spinae plane block for total shoulder arthroplasty: a randomized controlled trial.

PURPOSE: The high-thoracic erector spinae plane block (HT-ESPB) has been reported as an effective analgesic modality for the shoulder region without phrenic nerve palsy. The goal of this study was to compare the HT-ESPB as a phrenic nerve-sparing alternative to an interscalene block for total shoulder arthroplasty. METHODS: Thirty patients undergoing total shoulder arthroplasty at Stanford Health Care (Palo Alto, CA, USA) were enrolled in a double-blind randomized controlled trial. We randomized 28 patients to receive either an interscalene or HT-ESPB perineural catheter preoperatively; 26 patients were included in the final analysis. The study was powered for the primary outcome of incidence of hemidiaphragmatic paralysis in the postanesthesia care unit (PACU). Other outcome measures included incentive spirometry volume, brachial plexus motor and sensory exams, adverse events, pain scores, and opioid consumption. RESULTS: The incidence of hemidiaphragmatic paralysis in the HT-ESPB catheter group was significantly lower than in the interscalene catheter group (0/12, 0% vs 14/14, 100%; P < 0.001). No statistically significant differences were found in pain scores and opioid consumption (in oral morphine equivalents) between the interscalene and HT-ESPB groups through postoperative day (POD) 2. Nevertheless, the mean (standard deviation) point estimates for opioid consumption for the HT-ESPB group were higher than for the interscalene group in the PACU (HT-ESPB: 24.8 [26.7] mg; interscalene: 10.7 [21.7] mg) and for POD 0 (HT-ESPB: 20.5 [25.0] mg; interscalene: 6.7 [12.0] mg). In addition, cumulative postoperative opioid consumption was significantly higher at POD 0 (PACU through POD 0) in the HT-ESPB group (45.3 [39.9] mg) than in the interscalene group (16.6 [21.9] mg; P = 0.04). CONCLUSIONS: This study suggests that continuous HT-ESPB can be a phrenic nerve-sparing alternative to continuous interscalene brachial plexus blockade, although the latter provided superior opioid-sparing in the immediate postoperative period. This was a small sample size study, and further investigations powered to detect differences in analgesic and quality of recovery score endpoints are needed. STUDY REGISTRATION: www. CLINICALTRIALS: gov (NCT03807505); registered 17 January 2019.

RéSUMé: OBJECTIF: Le bloc des muscles érecteurs du rachis du haut thorax (BMER-HT) a été rapporté comme une modalité analgésique efficace pour la région de l'épaule et ce, sans paralysie du nerf phrénique. L'objectif de cette étude était de comparer ce bloc en tant qu'alternative épargnant le nerf phrénique à un bloc interscalénique pour l'arthroplastie totale de l'épaule. MéTHODE: Trente patients bénéficiant d'une arthroplastie totale de l'épaule au centre de soins Stanford Health Care (Palo Alto, CA, États-Unis) ont été recrutés dans une étude randomisée contrôlée à double insu. Nous avons randomisé 28 patients à recevoir un cathéter périneural interscalénique ou un BMER-HT en préopératoire; 26 patients ont été inclus dans l'analyse finale. Le calcul de puissance de l'étude a été effectué pour répondre au critère d'évaluation principal, qui était l'incidence de paralysie hémidiaphragmatique en salle de réveil. Les autres issues mesurées comprenaient les volumes de spirométrie, les examens moteurs et sensoriels du plexus brachial, les événements indésirables, les scores de douleur et la consommation d'opioïdes. RéSULTATS: L'incidence de paralysie hémidiaphragmatique dans le groupe cathéter BMER-HT était significativement plus faible que dans le groupe cathéter interscalénique (0/12, 0 % vs 14/14, 100 %; P < 0,001). Aucune différence statistiquement significative n'a été observée dans les scores de douleur et la consommation d'opioïdes (en équivalents morphine par voie orale) entre les groupes interscalénique et BMER-HT jusqu'au jour postopératoire (JPO) 2. Néanmoins, en salle de réveil, les estimations ponctuelles moyennes (écart type) de la consommation d'opioïdes pour le groupe BMER-HT étaient plus élevées que pour le groupe interscalénique (BMER-HT : 24,8 [26,7] mg; interscalénique : 10,7 [21,7] mg), ainsi qu'au JPO 0 (BMER-HT : 20,5 [25,0] mg; interscalénique: 6,7 [12,0] mg). De plus, la consommation cumulative d'opioïdes postopératoires était significativement plus élevée au JPO 0 (salle de réveil jusqu'au JPO 0) dans le groupe BMER-HT (45,3 [39,9] mg) que dans le groupe interscalénique (16,6 [21,9] mg; P = 0,04). CONCLUSION: Cette étude suggère que le BMER-HT continu peut être une alternative au bloc interscalénique continu du plexus brachial pour épargner le nerf phrénique, bien que le bloc interscalénique ait fourni une épargne d'opioïdes supérieure en période postopératoire immédiate. Il s'agissait d'une étude de petite taille d'échantillon, et d'autres études visant à détecter les différences dans les scores des critères d'évaluation en matière d'analgésie et de qualité de la récupération sont nécessaires. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03807505); enregistrée le 17 janvier 2019.

Arthroscopic Single and Double Row Repair of Isolated and Combined Subscapularis Tears Result in Similar Improvements in Outcomes: A Systematic Review.

PURPOSE: To systematically review the literature to (1) describe arthroscopic subscapularis repair constructs and outcomes in patients with isolated and combined subscapularis tears and (2) compare outcomes after single- and double-row subscapularis repair in both of these settings. METHODS: A systematic review was performed using PRISMA guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for Level I-IV evidence studies that investigated outcomes after arthroscopic subscapularis repair for the treatment of isolated subscapularis tears or subscapularis tears combined with posterosuperior rotator cuff tears in adult human patients. Data recorded included study demographics, repair construct, shoulder-specific outcome measures, and subscapularis retears. Study methodological quality was analyzed using the MINORS score. Heterogeneity and low levels of evidence precluded meta-analysis. RESULTS: The initial search yielded 811 articles (318 duplicates, 493 screened, 67 full-text review). Forty-three articles (2406 shoulders, 57% males, mean age range 42 to 67.5 years, mean MINORS score 13.4 ± 4.1) were included and analyzed. Articles reported on patients with isolated subscapularis tears (n = 15), combined tears (n = 17), or both (n = 11). The majority of subscapularis repairs used single-row constructs (89.4% of isolated tears, 88.9% of combined tears). All except for one study reporting on outcome measures found clinically significant improvements after subscapularis repair, and no clinically significant differences were detected in 5 studies comparing isolated to combined tears. Subscapularis retear rates ranged from 0% to 17% for isolated tears and 0% to 32% for combined subscapularis and posterosuperior rotator cuff tears. Outcomes and retear rates were similar in studies comparing single-row to double-row repair for isolated and combined subscapularis tears (P > .05 for all). CONCLUSION: Arthroscopic subscapularis repair resulted in significant improvements across all outcome measures, regardless of whether tears were isolated or combined or if repairs were single or double row. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.

Outcomes after resection arthroplasty versus permanent antibiotic spacer for salvage treatment of shoulder periprosthetic joint infections: a systematic review and meta-analysis.

BACKGROUND: Although revision to new components is favored after shoulder periprosthetic joint infections (PJIs), implant exchange is not always feasible. In certain cases, definitive treatment may be retainment of an antibiotic spacer or resection arthroplasty. The purpose of this investigation was to systematically review the literature for studies reporting on outcomes after resection arthroplasty or permanent antibiotic spacer for salvage treatment of shoulder PJIs. METHODS: A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for Level I-IV studies that reported on the final treatment of periprosthetic shoulder infections using resection arthroplasty or a permanent antibiotic spacer. Data recorded included study demographics, causative infectious organism, shoulder-specific range of motion and outcome measures, and infection eradication rate. Study methodological quality was analyzed using the Methodological Index for Non-Randomized Studies score. Forest plots of proportions and meta-analyses of single means were generated for infection eradication rates and outcomes, respectively. Heterogeneity was quantified using the I2 statistic. A P value of .05 was set as significant. RESULTS: The initial search yielded 635 articles (211 duplicates, 424 screened, 57 full-text review). Twenty-three articles (126 resection arthroplasty and 177 retained antibiotic spacer patients, 51% females, mean age range 37-78.5 years, mean Methodological Index for Non-Randomized Studies score 9.6 ± 0.7) were included and analyzed. The pooled infection eradication rate was 82% (72%-89%) after resection arthroplasty and 85% (79%-90%) after permanent antibiotic spacer. The pooled mean forward flexion (71.5° vs. 48.7°; P < .001) and mean American Shoulder and Elbow Surgeons score (53.5 vs. 31.0; P < .001) were significantly higher for patients treated with a permanent antibiotic spacer compared with resection arthroplasty. No significant differences were found for mean external rotation (13.5° vs. 20.5°; P = .07), abduction (58.2° vs. 50.3°; P = .27), or visual analog scale pain (3.7 vs. 3.4; P = .24) between groups. There was a statistically significant, but not clinically significant, difference in mean Constant score between permanent antibiotic spacer and resection arthroplasty patients (33.6 vs. 30.0; P < .001). CONCLUSION: When implant exchange after shoulder PJI is not feasible, permanent antibiotic spacers and resection arthroplasty are both salvage procedures that provide similar rates of infection eradication. Although both can decrease pain levels, the permanent antibiotic spacer may result in better functional outcomes compared with resection arthroplasty.

Pain management in shoulder arthroplasty: a systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: Postoperative pain management after total shoulder arthroplasty (TSA) can be challenging. Given the variety of pain management options available, the purpose of this investigation was to systematically review the literature for randomized controlled trials reporting on pain control after shoulder arthroplasty. We sought to determine which modalities are most effective in managing postoperative pain and reducing postoperative opioid use. METHODS: A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. PubMed, Scopus, and the Cochrane Central Register of Controlled Trials were searched for Level I-II randomized controlled trials that compared interventions for postoperative pain control after TSA. Pain control measures included nerve blocks and nerve block adjuncts, local injections, patient-controlled analgesia, oral medications, and other modalities. The 2 primary outcome measures were pain level measured on a 0-10 visual analog scale and opioid use. The risk of study bias and methodologic quality were analyzed using The Cochrane Collaboration's Risk of Bias 2 (RoB 2) tool. Network meta-analyses were performed for visual analog scale pain scores at postsurgical time points and opioid use using a frequentist approach and random-effects model, with heterogeneity quantified using the I2 statistic. Treatments were ranked using the P score, and statistical significance was set at P < .05. RESULTS: The initial search yielded 2391 articles (695 duplicates, 1696 screened, 53 undergoing full-text review). Eighteen articles (1358 shoulders; 51% female patients; mean age range, 65-73.7 years; 4 studies with low risk of bias, 12 with some risk, and 2 with high risk) were included and analyzed. At 4 and 8 hours postoperatively, patients receiving local liposomal bupivacaine (LB) injection (P < .001 for 4 and 8 hours) or local ropivacaine injection (P < .001 for 4 hours and P = .019 for 8 hours) had significantly more pain compared with patients who received either a continuous interscalene block (cISB) or single-shot interscalene block (ssISB). No differences in opioid use (at P < .05) were detected between modalities. The P scores of treatments demonstrated that ssISBs were most favorable at time points < 24 hours, whereas pain at 24 and 48 hours after surgery was best managed with cISBs or a combination of an ssISB with a local LB injection. CONCLUSION: Interscalene blocks are superior to local injections alone at managing pain after TSA. Single-shot interscalene blocks are optimal for reducing early postoperative pain (< 24 hours), whereas pain at 24-48 hours after surgery may be best managed with cISBs or a combination of an ssISB with a local LB injection.

Intersurgeon and intrasurgeon variability in preoperative planning of anatomic total shoulder arthroplasty: a quantitative comparison of 49 cases planned by 9 surgeons.

BACKGROUND: Preoperative planning software is widely available for most anatomic total shoulder arthroplasty (ATSA) systems. It can be most useful in determining implant selection and placement with advanced glenoid wear. The purpose of this study was to quantify inter- and intrasurgeon variability in preoperative planning of a series of ATSA cases. METHODS: Forty-nine computed tomography scans were planned for ATSA by 9 fellowship-trained shoulder surgeons using the ExactechGPS platform (Exactech Inc., Gainesville, FL, USA). Each case was planned a second time between 4 and 12 weeks later. Variability within and between surgeons was measured for implant type, size, version and inclination correction, and implant face position. Interclass correlation coefficients, Pearson, and Light's kappa coefficients were used for statistical analysis. RESULTS: There was considerable variation in the frequency of augment use between surgeons and between rounds for the same surgeon. Thresholds for augment use also varied between surgeons. Interclass correlation coefficients for intersurgeon variability were 0.37 for version, 0.80 for inclination, 0.36 for implant type, and 0.36 for implant size. Pearson coefficients for intrasurgeon variability were 0.17 for version and 0.53 for inclination. Light's kappa coefficient for implant type was 0.64. CONCLUSIONS: This study demonstrates substantial inter- and intrasurgeon variability in preoperative planning of ATSA. Although the magnitude of differences in correction was small, surgeons differed significantly in the use of augments to achieve the resultant plan. Surgeons differed from each other on thresholds for augment use and maximum allowable residual retroversion. This suggests that there may a range of acceptable corrections for each shoulder rather than a single optimal plan.

Assessment of surgeon variability in preoperative planning of reverse total shoulder arthroplasty: a quantitative comparison of 49 cases planned by 9 surgeons.

BACKGROUND: Preoperative planning software is gaining utility in reverse total shoulder arthroplasty (RTSA), particularly when addressing pathologic glenoid wear. The purpose of this study was to quantify inter- and intrasurgeon variability in preoperative planning a series of RTSA cases to identify differences in how surgeons consider optimal implant placement. This may help identify opportunities to establish consensus when correlating plan differences with clinical data. METHODS: A total of 49 computed tomography scans from actual RTSA cases were planned for RTSA by 9 fellowship-trained shoulder surgeons using the same platform (Exactech GPS, Exactech Inc., Gainesville, FL, USA). Each case was planned a second time 6-12 weeks later. Variability within and between surgeons was measured for implant selection, version correction, inclination correction, and implant face position. Interclass correlation coefficients, and Pearson and Light's kappa coefficient were used for statistical analysis. RESULTS: There was considerable variation in the frequency of augmented baseplate selection between surgeons and between rounds for the same surgeon. Thresholds for augment use also varied between surgeons. Interclass correlation coefficients for intersurgeon variability ranged from 0.43 for version, 0.42 for inclination, and 0.25 for baseplate type. Pearson coefficients for intrasurgeon variability were 0.34 for version and 0.30 for inclination. Light's kappa coefficient for baseplate type was 0.61. CONCLUSIONS: This study demonstrates substantial variability both between surgeons and between rounds for individual surgeons when planning RTSA. Although average differences between plans were relatively small, there were large differences in specific cases suggesting little consensus on optimal planning parameters and opportunities to establish guidelines based on glenoid pathoanatomy. The correlation of preoperative planning with clinical outcomes will help to establish such guidelines.

Elbow Trauma Sequelae: Instability, Stiffness, Non-arthroplasty, and Arthroplasty Options.

Sequelae of elbow trauma are complicated to manage. Undiagnosed instability patterns are important to recognize to get the elbow into concentric alignment for further reconstructive efforts. Stiffness is also common after elbow trauma. Surgeons should be familiar with the different approaches to the elbow to safely address stiffness. Non-arthroplasty and arthroplasty salvage options are also important to understand because the indications are expanding and outcomes for these procedures are being better understood.

Clinical and radiographic comparison of a hybrid cage glenoid to a cemented polyethylene glenoid in anatomic total shoulder arthroplasty.

BACKGROUND: This study reports the clinical and radiographic outcomes of a hybrid cage glenoid compared with an age-matched, sex-matched, and follow-up-matched cohort of cemented all-polyethylene peg glenoids in patients undergoing anatomic total shoulder arthroplasty with 2 years' minimum follow-up. MATERIALS AND METHODS: We reviewed 632 primary anatomic total shoulder arthroplasty patients from an international multi-institutional database; 316 patients received hybrid cage glenoids and were matched for age, sex, and follow-up with 316 patients with cemented all-polyethylene peg glenoids. Each cohort received the same humeral component. Scoring was performed in all patients preoperatively and at latest follow-up using 5 outcome scoring metrics and 4 active range-of-motion measurements. A Student 2-tailed unpaired t test identified differences in outcomes; P < .05 denoted a significant difference. RESULTS: Cage glenoid patients had significantly lower rates of radiolucent glenoid lines (9.0% vs. 37.6%, P < .0001) and radiolucent humeral lines (3.0% vs. 9.1%, P = .0088) than all-polyethylene peg glenoid patients. In the cage glenoid cohort, 4 cases of aseptic glenoid loosening (1.3%) and 4 cases of articular surface dissociation (1.3%) occurred. In the all-polyethylene peg cohort, 12 cases of aseptic loosening (3.8%) occurred. Cage glenoid patients had a significantly lower revision rate than all-polyethylene peg glenoid patients (2.5% vs. 6.9%, P = .0088). CONCLUSION: At 50 months' mean follow-up, cage glenoids demonstrated equally good clinical outcomes to all-polyethylene peg glenoids. Cage glenoids had significantly fewer radiolucent lines around both the glenoid and humeral components and a lower revision rate. Longer-term follow-up is required to confirm these promising short-term results.

Functionally Graded, Bone- and Tendon-Like Polyurethane for Rotator Cuff Repair.

Critical considerations in engineering biomaterials for rotator cuff repair include bone-tendon-like mechanical properties to support physiological loading and biophysicochemical attributes that stabilize the repair site over the long-term. In this study, UV-crosslinkable polyurethane based on quadrol (Q), hexamethylene diisocyante (H), and methacrylic anhydride (M; QHM polymers), which are free of solvent, catalyst, and photoinitiator, is developed. Mechanical characterization studies demonstrate that QHM polymers possesses phototunable bone- and tendon-like tensile and compressive properties (12-74 MPa tensile strength, 0.6-2.7 GPa tensile modulus, 58-121 MPa compressive strength, and 1.5-3.0 GPa compressive modulus), including the capability to withstand 10 000 cycles of physiological tensile loading and reduce stress concentrations via stiffness gradients. Biophysicochemical studies demonstrate that QHM polymers have clinically favorable attributes vital to rotator cuff repair stability, including slow degradation profiles (5-30% mass loss after 8 weeks) with little-to-no cytotoxicity in vitro, exceptional suture retention ex vivo (2.79-3.56-fold less suture migration relative to a clinically available graft), and competent tensile properties (similar ultimate load but higher normalized tensile stiffness relative to a clinically available graft) as well as good biocompatibility for augmenting rat supraspinatus tendon repair in vivo. This work demonstrates functionally graded, bone-tendon-like biomaterials for interfacial tissue engineering.

Are Age and Patient Gender Associated With Different Rates and Magnitudes of Clinical Improvement After Reverse Shoulder Arthroplasty?

BACKGROUND: An improved understanding of how gender differences and the natural aging process are associated with differences in clinical improvement in outcome metric scores and ROM measurements after reverse total shoulder arthroplasty (rTSA) may help physicians establish more accurate patient expectations for reducing postoperative pain and improving function. QUESTIONS/PURPOSES: (1) Is gender associated with differences in rTSA outcome scores like the Simple Shoulder Test (SST), the UCLA Shoulder score, the American Shoulder and Elbow Surgeons (ASES) Shoulder score, the Constant Shoulder score, and the Shoulder Pain and Disability Index (SPADI) and ROM? (2) Is age associated with differences in rTSA outcome scores and ROM? (3) What factors are associated with the combined interaction effect between age and gender? (4) At what time point during recovery does most clinical improvement occur, and when is full improvement reached? METHODS: We quantified and analyzed the outcomes of 660 patients (424 women and 236 men; average age, 72 ± 8 years; range, 43-95 years) with cuff tear arthropathy or osteoarthritis and rotator cuff tear who were treated with rTSA by 13 shoulder surgeons from a longitudinally maintained international database using a linear mixed effects statistical model to evaluate the relationship between clinical improvements and gender and patient age. We used five outcome scoring metrics and four ROM assessments to evaluate clinical outcome differences. RESULTS: When controlling for age, men had better SST scores (mean difference [MD] = 1.41 points [95% confidence interval {CI}, 1.07-1.75], p < 0.001), UCLA scores (MD = 1.76 [95% CI, 1.05-2.47], p < 0.001), Constant scores (MD = 6.70 [95% CI, 4.80-8.59], p < 0.001), ASES scores (MD = 7.58 [95% CI, 5.27-9.89], p < 0.001), SPADI scores (MD = -12.78 [95% CI, -16.28 to -9.28], p < 0.001), abduction (MD = 5.79° [95% CI, 2.74-8.84], p < 0.001), forward flexion (MD = 7.68° [95% CI, 4.15-11.20], p < 0.001), and passive external rotation (MD = 2.81° [95% CI, 0.81-4.8], p = 0.006). When controlling for gender, each 1-year increase in age was associated with an improved ASES score by 0.19 points (95% CI, 0.04-0.34, p = 0.011) and an improved SPADI score by -0.29 points (95% CI, -0.46 to 0.07, p = 0.020). However, each 1-year increase in age was associated with a mean decrease in active abduction by 0.26° (95% CI, -0.46 to 0.07, p = 0.007) and a mean decrease of forward flexion by 0.39° (95% CI, -0.61 to 0.16, p = 0.001). A combined interaction effect between age and gender was found only with active external rotation: in men, younger age was associated with less active external rotation and older age was associated with more active external rotation (ß0 [intercept] = 11.029, ß1 [slope for age variable] = 0.281, p = 0.009). Conversely, women achieved no difference in active external rotation after rTSA, regardless of age at the time of surgery (ß0 [intercept] = 34.135, ß1 [slope for age variable] = -0.069, p = 0.009). Finally, 80% of patients achieved full clinical improvement as defined by a plateau in their outcome metric score and 70% of patients achieved full clinical improvement as defined by a plateau in their ROM measurements by 12 months followup regardless of gender or patient age at the time of surgery with most improvement occurring in the first 6 months after rTSA. CONCLUSIONS: Gender and patient age at the time of surgery were associated with some differences in rTSA outcomes. Men had better outcome scores than did women, and older patients had better outcome scores but smaller improvements in function than did younger patients. These results demonstrate rTSA outcomes differ for men and women and for different patient ages at the time of surgery, knowledge of these differences, and also the timing of improvement plateaus in outcome metric scores and ROM measurements can both improve the effectiveness of patient counseling and better establish accurate patient expectations after rTSA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Instability after reverse total shoulder arthroplasty.

BACKGROUND: This study evaluated patients with and without a prosthetic dislocation after reverse total shoulder arthroplasty (RTSA) to identify risk factors for instability. METHODS: Dislocation and nondislocation cohorts were established for analysis in 119 patients who had undergone RTSA at our institution between 2011 and 2014. Preoperative history and parameters pertaining to RTSA design were evaluated for correlation with instability. A logistic regression model was used to analyze independent predictors. RESULTS: Eleven patients (9.2%) demonstrated instability in the early postoperative period. Dislocations occurred at an average of 8 weeks postoperatively (range, 3 days-5 months). The mean follow-up of all patients was 28 months (range, 6-106 months). Postoperative instability was associated with male gender, history of prior open shoulder surgery, and preoperative diagnoses of fracture sequelae, particularly proximal humeral or tuberosity nonunion. Absence of subscapularis repair was an independent predictor of instability. In addition, 5 of the 11 patients (45%) in the instability cohort sustained a second dislocation requiring another operation. CONCLUSIONS: Redislocation after revision surgery for the initial dislocation was an unexpected and alarming finding. Treatment for the initial dislocation event by placement of a thicker polyethylene insert was inadequate in 45% of patients of our cohort and required another revision with a larger glenosphere and thicker humeral inserts. Initial instability after RTSA must be carefully managed, especially in the revision and post-traumatic setting. Exchange to a thicker polyethylene insert only carries a higher risk of recurrent instability.

Shoulder Arthroplasty: Key Steps to Improve Outcomes and Minimize Complications.

Advances in shoulder replacement surgery have allowed for the successful treatment of various shoulder conditions. As the elderly population increases and the surgical indications for shoulder replacement surgery continue to expand, the number of shoulder replacements performed annually will continue to increase. Accordingly, the number of complications also will be expected to increase. Successful shoulder replacement outcomes require surgeons to have a thorough understanding of the surgical indications, surgical technique, and potential complications of the procedure. By reviewing the key aspects of shoulder replacement surgery and focusing on the surgical technique and common complications for both anatomic and reverse total shoulder arthroplasty, surgeons can help improve outcomes and minimize complications.

Posterior glenoid wear in total shoulder arthroplasty: eccentric anterior reaming is superior to posterior augment.

BACKGROUND: Uncorrected glenoid retroversion during total shoulder arthroplasty may lead to an increased likelihood of glenoid prosthetic loosening. Augmented glenoid components seek to correct retroversion to address posterior glenoid bone loss, but few biomechanical studies have evaluated their performance. QUESTIONS/PURPOSES: We compared the use of augmented glenoid components with eccentric reaming with standard glenoid components in a posterior glenoid wear model. The primary outcome for biomechanical stability in this model was assessed by (1) implant edge displacement in superior and inferior edge loading at intervals up to 100,000 cycles, with secondary outcomes including (2) implant edge load during superior and inferior translation at intervals up to 100,000 cycles, and (3) incidence of glenoid fracture during implant preparation and after cyclic loading. METHODS: A 12°-posterior glenoid defect was created in 12 composite scapulae, and the specimens were divided in two equal groups. In the posterior augment group, glenoid version was corrected to 8° and an 8°-augmented polyethylene glenoid component was placed. In the eccentric reaming group, anterior glenoid reaming was performed to neutral version and a standard polyethylene glenoid component was placed. Specimens were cyclically loaded in the superoinferior direction to 100,000 cycles. Superior and inferior glenoid edge displacements were recorded. RESULTS: Surviving specimens in the posterior augment group showed greater displacement than the eccentric reaming group of superior (1.01 ± 0.02 [95% CI, 0.89-1.13] versus 0.83 ± 0.10 [95% CI, 0.72-0.94 mm]; mean difference, 0.18 mm; p = 0.025) and inferior markers (1.36 ± 0.05 [95% CI, 1.24-1.48] versus 1.20 ± 0.09 [95% CI, 1.09-1.32 mm]; mean difference, 0.16 mm; p = 0.038) during superior edge loading and greater displacement of the superior marker during inferior edge loading (1.44 ± 0.06 [95% CI, 1.28-1.59] versus 1.16 ± 0.11 [95% CI, 1.02-1.30 mm]; mean difference, 0.28 mm; p = 0.009) at 100,000 cycles. No difference was seen with the inferior marker during inferior edge loading (0.93 ± 0.15 [95% CI, 0.56-1.29] versus 0.78 ± 0.06 [95% CI, 0.70-0.85 mm]; mean difference, 0.15 mm; p = 0.079). No differences in implant edge load were seen during superior and inferior loading. There were no instances of glenoid vault fracture in either group during implant preparation; however, a greater number of specimens in the eccentric reaming group were able to achieve the final 100,000 time without catastrophic fracture than those in the posterior augment group. CONCLUSIONS: When addressing posterior glenoid wear in surrogate scapula models, use of angle-backed augmented glenoid components results in accelerated implant loosening compared with neutral-version glenoid after eccentric reaming, as shown by increased implant edge displacement at analogous times. CLINICAL RELEVANCE: Angle-backed components may introduce shear stress and potentially compromise stability. Additional in vitro and comparative long-term clinical followup studies are needed to further evaluate this component design.

Patient adherence with postoperative restrictions after rotator cuff repair.

HYPOTHESIS: This study aimed to measure self-reported patient adherence to postoperative restrictions after rotator cuff repair, to evaluate correlations between adherence and functional outcome, and to identify possible indicators of poor adherence. We believed that poor adherence would correlate with poor functional outcome. METHODS: Fifty consecutive patients undergoing repair for rotator cuff tears were included and instructed to wear an abduction brace for 6 weeks after surgery. Functional evaluations, including American Shoulder and Elbow Surgeons score, University of California-Los Angeles shoulder score, and Simple Shoulder Test, were made preoperatively and postoperatively. Patients commented on their adherence with a medical adherence measurement questionnaire. RESULTS: Average adherence was 88% (range, 59.2-100). There were no significant correlations between adherence and improvement in American Shoulder and Elbow Surgeons, University of California-Los Angeles, or Simple Shoulder Test scores after rotator cuff repair (P = .06245, .5891, and .7688). Of the patient demographics analyzed, only smoking status had a positive effect on adherence (P = .00432; coefficient, 9.867). All other demographics, including hand dominance, mechanism of injury, repair complexity, comorbidities, living status, employment status, and age, had no significant effect on self-measured adherence to postoperative restrictions (P = .7876, .5889, .6444, .4190, .0609, .4171, .5402). CONCLUSIONS: Patients' self-reported adherence did not correlate with shoulder outcome as measured on any of 3 functional outcome scores.

High accuracy of intra-articular needle position during anterior landmark guided glenohumeral injections.

OBJECTIVES: Image-guided ultrasound or fluoroscopic glenohumeral injections have high accuracy rates but require training, equipment, cost, and radiation exposure (fluoroscopy). In contrast, landmark-guided glenohumeral injections do not require additional subspecialist referrals or equipment. An optimal technique would be safe and accurate and have few barriers to implementation. The purpose of this study was to define the accuracy of glenohumeral needle placement via an anterior landmark-guided approach as assessed by direct arthroscopic visualization. METHODS: A consecutive series of adult patients undergoing shoulder arthroscopy in the beach chair position were included in this study. Demographic and procedural data were collected. The time required to perform the injection, the precise location of the needle tip, and factors that affected the accuracy of the injection were also assessed. RESULTS: A standardized anterior landmark-guided glenohumeral joint injection was performed in the operating room prior to surgery, and the location of the needle tip was documented by arthroscopic visualization with a low complication profile and few barriers to implementation. A total of 81 patients were enrolled. Successful intra-articular glenohumeral needle placement by sports medicine and shoulder/elbow fellowship-trained orthopedic surgeons was confirmed in 93.8% (76/81) of patients. The average time to complete the procedure was 24.8 â€‹s. There were no patient-related variables associated with nonintra-articular injections in the cohort. CONCLUSIONS: This study demonstrated that the technique of anterior landmark-guided glenohumeral injection has an accuracy of 93.8% and requires less than 30 â€‹s to perform. This method is safe, yields similar accuracy to image-guided procedures, has improved cost and time efficiency, and requires less radiation exposure. No patient-related factors were associated with inaccurate needle placement. Anterior landmark-guided glenohumeral injections may be utilized with confidence by providers in the clinical setting. LEVEL OF EVIDENCE: Level 5. IRB: Approved under Stanford IRB-56323.

Optimizing Tissue Engineering for Clinical Relevance in Rotator Cuff Repair.

Rotator cuff tear (RCT) is the most common cause of disability in the upper extremity. It results in 4.5 million physician visits in the United States every year and is the most common etiology of shoulder conditions evaluated by orthopedic surgeons. Over 460,000 RCT repair surgeries are performed in the United States annually. Rotator cuff (RC) retear and failure to heal remain significant postoperative complications. Literature suggests that the retear rates can range from 29.5% to as high as 94%. Weakened and irregular enthesis regeneration is a crucial factor in postsurgical failure. Although commercially available RC repair grafts have been introduced to augment RC enthesis repair, they have been associated with mixed clinical outcomes. These grafts lack appropriate biological cues such as stem cells and signaling molecules at the bone-tendon interface. In addition, they do little to prevent fibrovascular scar tissue formation, which causes the RC to be susceptible to retear. Advances in tissue engineering have demonstrated that mesenchymal stem cells (MSCs) and growth factors (GFs) enhance RC enthesis regeneration in animal models. These models show that delivering MSCs and GFs to the site of RCT enhances native enthesis repair and leads to greater mechanical strength. In addition, these models demonstrate that MSCs and GFs may be delivered through a variety of methods including direct injection, saturation of repair materials, and loaded microspheres. Grafts that incorporate MSCs and GFs enhance anti-inflammation, osteogenesis, angiogenesis, and chondrogenesis in the RC repair process. It is crucial that the techniques that have shown success in animal models are incorporated into the clinical setting. A gap currently exists between the promising biological factors that have been investigated in animal models and the RC repair grafts that can be used in the clinical setting. Future RC repair grafts must allow for stable implantation and fixation, be compatible with current arthroscopic techniques, and have the capability to deliver MSCs and/or GFs.

Host and microbial characteristics associated with recurrent prosthetic joint infections.

Approximately 20% of patients after resection arthroplasty and antibiotic spacer placement for prosthetic joint infection develop repeat infections, requiring an additional antibiotic spacer before definitive reimplantation. The host and bacterial characteristics associated with the development of recurrent infection is poorly understood. A case-control study was conducted for 106 patients with intention to treat by two-stage revision arthroplasty for prosthetic joint infection at a single institution between 2009 and 2020. Infection was defined according to the 2018 Musculoskeletal Infection Society criteria. Thirty-nine cases ("recurrent-periprosthetic joint infection [PJI]") received at least two antibiotic spacers before clinical resolution of their infection, and 67 controls ("single-PJI") received a single antibiotic cement spacer before infection-free prosthesis reimplantation. Patient demographics, McPherson host grade, and culture results including antibiotic susceptibilities were compared. Fifty-two (78%) single-PJI and 32 (82%) recurrent-PJI patients had positive intraoperative cultures at the time of their initial spacer procedure. The odds of polymicrobial infections were 11-fold higher among recurrent-PJI patients, and the odds of significant systemic compromise (McPherson host-grade C) were more than double. Recurrent-PJI patients were significantly more likely to harbor Staphylococcus aureus. We found no differences between cases and controls in pathogen resistance to the six most tested antibiotics. Among recurrent-PJI patients, erythromycin-resistant infections were more prevalent at the final than initial spacer, despite no erythromycin exposure. Our findings suggest that McPherson host grade, polymicrobial infection, and S. aureus infection are key indicators of secondary or persistent joint infection following resection arthroplasty and antibiotic spacer placement, while bacterial resistance does not predict infection-related arthroplasty failure.

Biomechanical evaluation of a coracoclavicular and acromioclacicular ligament reconstruction technique utilizing a single continuous intramedullary free tendon graft.

BACKGROUND: Reconstruction of only the coracoclavicular (CC) ligaments may restore superior-inferior (S-I) but not anterior-posterior (A-P) stability of the acromioclavicular (AC) joint. Concomitant reconstruction of both the AC and CC ligaments may more reliably restore intact biomechanical characteristics of the AC joint. METHODS: Ten matched pairs of shoulders were utilized. Five specimens underwent CC ligament reconstruction while an equal number underwent combined AC and CC ligament reconstruction utilizing an intramedullary tendon graft. Each of the reconstructions was compared with the intact contralateral control. Translational and load to failure characteristics were compared between groups. RESULTS: No difference was found in S-I translation between intact specimens and CC-only reconstructions (P = .20) nor between intact specimens and AC/CC reconstructions (P = .33) at 10 Newton (N) loads. Significant differences were noted in A-P translation between intact specimens and CC-only reconstructions (P < .001) but no difference in A-P translation between intact specimens and AC/CC reconstructions (P = .34). CONCLUSION: The A-P and S-I translational biomechanical characteristics of the AC joint were restored using the new technique described. Reconstruction of the CC ligaments only (versus AC/CC combined) led to significantly increased translational motion in the A-P plane as compared to intact control specimens.