Risk of Subsequent Fusion After Isolated Decompression of Lumbar Facet Cysts.

INTRODUCTION: Lumbar facet cysts represent a potential source of nerve root compression in elderly patients. Isolated decompression without fusion has proven to be a reasonable treatment option in properly indicated patients. However, the risk of lumbar fusion after isolated decompression and facet cyst excision has yet to be elucidated. METHODS: The PearlDiver database was reviewed for patients undergoing isolated laminectomy for lumbar facet cyst from January 2015 to December 2018 using Current Procedural Terminology coding. Patients undergoing concomitant fusion or additional decompression, as well as those diagnosed with preexisting spondylolisthesis or without a minimum of 5-year follow-up, were excluded. Rates of subsequent lumbar fusion and potential risk factors for subsequent fusion were identified. Statistical analysis included descriptive statistics, chi square test, and multivariate logistic regression. Results were considered significant at P < 0.05. RESULTS: In total, 10,707 patients were ultimately included for analysis. At 5-year follow-up, 727 (6.79%) of patients underwent subsequent lumbar fusion after initial isolated decompression. Of these, 301 (2.81% of total patients, 41.4% of fusion patients) underwent fusion within the first year after decompression. Multivariate analysis identified chronic kidney disease, hypertension, and osteoarthritis as risk factors for requiring subsequent lumbar fusion at 5 years following the index decompression procedure ( P < 0.033; all). CONCLUSION: Patients undergoing isolated decompression for lumbar facet cysts undergo subsequent lumbar fusion at a 5-year rate of 6.79%. Risk factors for subsequent decompression include chronic kidney disease, hypertension, and osteoarthritis. This study will assist spine surgeons in appropriately counseling patients on expected postoperative course and potential risks of isolated decompression.

Puncture Capsulotomy Technique for Hip Arthroscopy: Midterm Functional Outcomes.

Background: The most common surgical approaches in hip arthroscopy are interportal and T-capsulotomy. However, these methods may introduce capsular instability. Puncture capsulotomy preserves capsuloligamentous integrity by avoiding iatrogenic transection of the iliofemoral capsular ligament. Purpose: To present minimum 2-year functional outcomes for patients who underwent arthroscopic treatment for acetabular labral tears and concomitant femoroacetabular impingement using the puncture capsulotomy technique. Study Design: Case series; Level of evidence, 4. Methods: The authors conducted a retrospective review of prospectively collected data on patients who underwent arthroscopic acetabular labral tear treatment between December 2013 and May 2019. Included were patients aged ≥18 years who underwent hip arthroscopy by a single surgeon and completed a minimum of 2 years of patient-reported outcome measure (PROM) surveys. Intraoperatively, patients underwent hip arthroscopy via puncture capsulotomy to treat labral tears and any concomitant femoroacetabular impingement. Clinical outcome data consisted of PROMs. Results: A total of 163 hips were included; the mean patient follow-up was 30.4 months (range, 24-60 months; 95% CI, 28.5-32.3 months). Patients had a mean age of 37.9 years (range, 36.1-39.6 years), with a mean body mass index of 25.9 (range, 25.2-26.5). There were significant improvements in mean [95% CI] baseline to final follow-up scores for the 33-Item International Hip Outcome Tool (iHOT-33) (39.6 [36.8-42.4] vs 76.1 [72.7-79.6]), Hip Outcome Score-Activities of Daily Living (70.0 [67.0-73.0] vs 89.3 [87.3-91.3]), modified Harris Hip Score (60.1 [57.9-62.4] vs 84.9 [82.5-87.2]), and Hip Outcome Score-Sports Specific Subscale (41.8 [37.9-45.6] vs 75.7 [71.7-79.7]) (P < .001 for all). Additionally, the mean [95% CI] visual analog scale pain scores were noted to significantly improve throughout the duration of the postoperative period (from 6.3 [5.9-6.7] to 2.2 [1.8-2.6]; P < .001). There were no incidences of infection, avascular necrosis of the femoral head, dislocation/instability, or femoral neck fracture. At the 2-year follow-up, 81.0%, 62.0%, and 58.9% of hips achieved previously published clinically meaningful iHOT-33 thresholds for minimally clinically important difference, Patient Acceptable Symptom Score, and substantial clinical benefit, respectively. Conclusion: Puncture capsulotomy demonstrated significantly improved functional and clinically meaningful outcomes at a minimum 2-year follow-up, along with a minimal complication rate.

Cervical Alignment and Proximal and Distal Junctional Failure in Posterior Cervical Fusion: A Multicenter Comparison of 2 Surgical Approaches.

STUDY DESIGN: This was a multicenter retrospective cohort study. OBJECTIVE: The purpose of this study was to compare the surgical and radiographic outcomes of patients undergoing posterior cervical fusion (PCF) with constructs extending from C2 to T2 to patients with constructs extending from C3 to T1. SUMMARY OF BACKGROUND DATA: Limited evidence exists regarding the appropriate level of proximal and distal extension of PCF constructs. METHODS: A multicenter retrospective cohort study of patients who underwent PCF between 2012 and 2020 was performed. Surgical and radiographic outcomes were compared between those who had C3-T1 or C2-T2 constructs. RESULTS: A total of 155 patients were included in the study (C2-T2: 106 patients, C3-T1: 49 patients). There were no significant differences in demographics or preoperative symptoms between cohorts. Fusion rates were significantly higher in the C2-T2 (93%) than the C3-T1 (80%, P=0.040) cohort. When comparing the C2-T2 to the C3-T1 cohort, the C3-T1 cohort had a significantly greater rate of proximal junctional failure (2% vs. 10%, P=0.006), distal junctional failure (1% vs. 20%, P<0.001) and distal screw loosening (4% vs. 15%, P=0.02). Although ∆C2-C7 sagittal vertical axis increased significantly in both cohorts (C2-T2: 6.2 mm, P=0.04; C3-T1: 8.4 mm, P<0.001), correction did not significantly differ between groups (P=0.32). The C3-T1 cohort had a significantly greater increase in ∆C2 slope (8.0 vs. 3.1 degrees, P=0.03) and ∆C0-C2 Cobb angle (6.4 vs. 1.2 degrees, P=0.04). CONCLUSION: In patients undergoing PCF, a C2-T2 construct demonstrated lower rates of pseudarthrosis, distal junctional failure, proximal junctional failure, and compensatory upper cervical hyperextension compared with a C3-T1 construct.

Circumferential fusion with open versus percutaneous posterior fusion for lumbar isthmic spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate the clinical and radiographic differences between patients who underwent anterior lumber interbody fusion (ALIF) with either open or percutaneous posterior fusion for lumbar isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: Circumferential fusion for isthmic spondylolisthesis is commonly performed with superior clinical outcomes, fusion rates, and restoration of sagittal balance when compared to posterior fusion alone. The outcomes comparing traditional open versus percutaneous posterior fusion in this setting have not been fully evaluated. METHODS: A retrospective review of patients who underwent ALIF with either traditional open or percutaneous posterior fusion for isthmic spondylolisthesis between 2014 and 2019 was conducted. Patient demographics, surgical characteristics, and radiographic and clinical outcomes were compared between groups. RESULTS: A total of 79 patients were included in the final analysis, with 49 in the Open group and 30 in the Percutaneous group. No differences were found with regard to demographic factors between groups including sex, body mass index (BMI), diabetic status, and smoking status. The percutaneous group had less estimated blood loss (EBL, 69.2 mL) and shorter length of stay (3.06 days) compared to the open group (446 mL, p = 0.017; 3.98 days, p = 0.003). Both groups demonstrated significant improvement in all clinical outcome measures after surgery (PCS-12, MCS-12, ODI, VAS Back, and VAS Leg scores). The percutaneous group achieved greater ∆VAS Back (Open = 3.55, Perc = 5.17; p = 0.045) and also had a significantly greater improvements in recovery ratio for VAS Back (Open: 0.43, Perc: 0.73; p = 0.037) and ODI (Open: 0.40, Perc = 0.67; p = 0.031). Regression analysis demonstrated percutaneous surgery to be significant predictor of superior improvement in VAS Back scores (ß = 1.957, p = 0.027). CONCLUSION: ALIF with percutaneous posterior fusion affords greater improvement in back pain and disability when compared to ALIF with open posterior fusion for isthmic spondylolisthesis. LEVEL OF EVIDENCE: III.

How Does the Presence of a Surgical Trainee Impact Patient Outcomes in Lumbar Fusion Surgery?

BACKGROUND: While the impact of trainee involvement in other surgical fields is well established, there is a paucity of literature assessing this relationship in orthopaedic spine surgery. The goal of this study was to further elucidate this relationship. METHODS: A retrospective cohort study was initiated on patients undergoing 1-3 level lumbar spine fusion at a single academic center. Operative reports from cases were examined, and patients were divided into 2 groups depending on whether a fellow or resident (F/R) or a physician's assistant (PA) was used as the primary assist. Patients with less than 1-year follow-up were excluded. Multiple linear regression was used to assess change in each patient-reported outcome, and multiple binary logistic regression was used to determine significant predictors of revision, infection, and 30- or 90-day readmission. RESULTS: One hundred and seventy-two patients were included in the F/R group compared with 178 patients in the PA group. No differences existed between groups for total surgery time, length of stay, 30- or 90-day readmissions, infection, or revision rates. No differences existed between groups in terms of patient-reported outcomes preoperatively or postoperatively. In addition, presence of a surgical trainee was not a significant predictor of patient outcomes or rates of infection, overall revision, or 30- and 90-day readmission rates. CONCLUSIONS: The results of this study indicate the presence of an orthopaedic spine F/R does not increase complication rates and does not affect short-term patient-reported outcomes in lumbar decompression and fusion surgery. LEVEL OF EVIDENCE: 3.

Does Cervical Spondylolisthesis Influence Patient-Reported Outcomes After Anterior Cervical Discectomy and Fusion Surgery?

BACKGROUND: No prior work has explored whether the presence of degenerative spondylolisthesis impacts patient-reported outcome measurements (PROMs) after an anterior cervical discectomy and fusion (ACDF); therefore, the goal of the current study was to determine whether the presence of a spondylolisthesis affects PROMs after an ACDF. METHODS: A retrospective cohort study was conducted on patients over the age of 18 who underwent a 1- or 2-level ACDF. All patients received preoperative standing lateral x-rays and were placed into 1 of 2 groups based on the presence of cervical spondylolisthesis from C2-T1: (1) no spondylolisthesis (NS) group or (2) spondylolisthesis (S) group. Preoperative, postoperative, and delta (postoperative minus preoperative) were recorded and compared between groups via univariate and multivariate analysis. Outcomes reported were the Physical Component Scores of the Short Form-12 (PCS-12), the Mental Component Scores of the Short Form-12 (MCS-12), the Neck Disability Index (NDI), and visual analog scale (VAS) Arm/Neck. RESULTS: A total of 202 patients were included in the final analysis with 154 in the NS group and 48 in the S group. Both patient cohorts reported significant postoperative improvement in PCS-12, NDI, and VAS Arm/Neck. When comparing outcome scores between groups, only MCS-12 delta scores were different between groups, with the S group exhibiting a greater mean delta score (8.3 vs 1.3, P = 0.024) than the NS group after ACDF. Multiple linear regression analysis indicated having spondylolisthesis at baseline was a significant predictor of greater change in MCS-12 than the NS group (ß = 4.841; 95% CI, 0.876, 8.805; P = 0.017). CONCLUSION: Both groups demonstrated significant postoperative improvement in PCS-12, NDI, or VAS Neck/Arm pain scores with no significant differences between groups. Patients with spondylolisthesis were found to have significantly greater improvement scores in MCS-12 scoring than those without spondylolisthesis after ACDF surgery.

Endoscopic Repair of Full-Thickness Gluteus Medius and Minimus Tears-Prospective Study With a Minimum 2-Year Follow-Up.

PURPOSE: To evaluate the short-term outcomes of endoscopic repair of full-thickness gluteus medius and minimus tendon tears with a minimum of 2-year follow-up and add to the paucity of literature on abductor tendon tears. METHODS: All patients who underwent endoscopic abductor tendon repair between December 2013 and August 2017 were prospectively evaluated. The inclusion criteria for this study were primary full-thickness gluteal tendon tears and at least 2-years of follow-up. Clinical outcome data consisted of visual analog scale (VAS) pain score, hip abduction strength, Trendelenburg sign, complications, and patient-reported outcome measures (PROMs): modified Harris Hip Score, Hip Outcome Score, Non-arthritic Hip Scale, International Hip Outcome Tool-33, and Lower Extremity Functional Scale. RESULTS: A total of 15 hips, all full-thickness tears, met inclusion criteria with an average follow-up of 31.2 months, with no patients being excluded. On physical examination, there was a significant improvement in VAS pain score from 5.36 to 2.43 (P = .0243), hip abduction strength with 8 (53.3%) hips improving by at least 1 point (P = .02056), and resolution of Trendelenburg sign in all 15 hips at 2-years (P = .0019). The mean difference for all 6 PROMs was statistically significant, even after Bonferroni adjustment, with the majority of patient improvement exceeding the minimal clinically important difference (MCID) thresholds: modified Harris Hip Score: 86.67%, Hip Outcome Score-ADL: 86.67%, Hip Outcome Score-SSS: 66.67%, Non-arthritic Hip Scale: 93.33%, and International Hip Outcome Tool-33: 80%. Greater Goutallier grade was associated with a greater VAS pain score. There were no complications, including no retears. CONCLUSIONS: In this study of 15 hips with full-thickness gluteal tendon tears managed endoscopically, we found excellent outcomes that exceeded the MCID thresholds in the majority of patients at an average of 31.2 months follow-up, while offering the potential advantages of less tissue violation, ambulatory day surgery, and fewer complications compared with open repair. LEVEL OF EVIDENCE: Level 4, Case Series.

Translational relevance of the goat as a preclinical model of the human labrum and chondrolabral junction-histological study.

The purpose of this study was to evaluate the histologic features of the caprine labrum, with emphasis on the chondrolabral junction, with the goal of informing the feasibility of the goat as an animal model. The left hip joint of six adolescent Spanish goats (Capra pyrenaica) was harvested and subjected to anatomical and histological assessments. Human acetabular and femoral head samples, collected during total hip arthroplasty, served as comparison samples. The caprine labrum was found to consist of mostly type I collagen with uniform crimp, with an average crimp length of 20.8 µm. Upon histological assessment, acetabular articular chondrocytes were found to express substance-P, especially near or in the chondrolabral junction. And the majority of nonvascular cells expressed α-smooth muscle actin (SMA), with no notable elastin and laminin expression. Human labrum demonstrated similar staining patterns. Overall, the goat hip was found to be homologous to the human hip, demonstrating potential as a useful animal model for future studies. This is the first report of a crimped collagen structure in the labrum. Crimped type I collagen at the chondrolabral junction imparts an extension-recovery property which allows for toleration of stress without permanent deformation, underlying the importance of its preservation during surgery. The high expression of substance-P reflects the degree to which the labrum is innervated. Finally, the expression of α-SMA with contractile characteristics could indicate the potential for chondrocyte (i.e., myochondrocytes) modeling of the extracellular matrix. Statement of Clinical Significance: Establishment of a large animal model and deeper knowledge of the histological composition of the hip joint will enhance our study of the acetabular labrum, including repair techniques. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1070-1080, 2020.

Changing MRI after subchondroplasty with partial meniscectomy for knee osteoarthritis.

A 54-year old woman with primary osteoarthritis and a tibial bone marrow lesion underwent subchondroplasty with injectable calcium phosphate. Post-operatively, the patient's symptoms worsened, and she lost the ability to bear weight. Follow-up MRI revealed previously absent, diffuse STIR hyperintensity in the tibia extending far beyond the surgical site. Twelve months post-operatively, symptoms spontaneously resolved. As the prevalence of subchondroplasty grows it will be important to recognize potential complications. To the authors' best knowledge this is the first report of significantly worsening pain and difficulty bearing weight corresponding with diffuse hyperintense T2 signal in the tibia after a calcium phosphate subchondroplasty.

Outcome of Surgical Treatment of Hip Femoroacetabular Impingement Patients with Radiographic Osteoarthritis: A Meta-analysis of Prospective Studies.

INTRODUCTION: In this study, the prognostic value of osteoarthritis (OA) on the overall failure rate, pain, and function of surgical management of femoroacetabular impingement (FAI) was evaluated via meta-analysis. METHODS: Relevant comparative studies were obtained from PubMed, OVID, and Cochrane database up until April 2016. Studies were selected according to the eligibility criteria. The study design, participant characteristics, interventions, and outcomes were reviewed after the assessment of methodological quality of each trial. All data were analyzed by Review Manager 5.3. RESULTS: Seven studies were identified with 1,129 total patients, with 819 patients in the FAI group and 310 patients in the FAI with OA group. Pooled analyses showed that the overall failure rate was significantly higher in the FAI-OA group than in the FAI group (odds ratio, 8.50; 95% confidence interval, 4.44 to 16.26; P < 0.00001). In addition, the rate of conversion to total hip arthroplasty was significantly higher in the FAI-OA group (37.3%) than in the FAI group (9.7%) (odds ratio, 19.42; 95% confidence interval, 7.00 to 53.85; P < 0.00001). CONCLUSIONS: We found that radiographic OA was correlated with higher failure rates, increased conversion to total hip arthroplasty, and worse outcomes after surgical management of FAI. LEVEL OF EVIDENCE: Level II.

Improvement in Functional Outcome Scores Despite Persistent Pain With 1 Year of Nonsurgical Management for Acetabular Labral Tears With or Without Femoroacetabular Impingement.

BACKGROUND: Acetabular labral tears are increasingly recognized as a source of hip pain in a younger active population. Given the significant focus on surgical intervention, there has been limited investigation on the nonsurgical management and natural history of such injuries. HYPOTHESIS: Patients undergoing nonsurgical treatment for symptomatic acetabular labral tears experience functional improvement based on patient-reported outcome measures over the course of 1 year. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Seventy-one patients were identified who had acetabular labral injuries confirmed by magnetic resonance imaging or arthrography, received a minimum of 1 year of nonsurgical treatment, and completed baseline functional outcome questionnaires: modified Harris Hip Score (mHHS), Hip Outcome Score (HOS)-Activities of Daily Living, HOS-Sports, and iHOT-33 (International Hip Outcome Tool-33). Of these, 52 (73.2%) completed the minimum 1-year follow-up questionnaires. Chart review was conducted to obtain demographic information. Statistical significance ( P < .05) was determined by paired t test, independent samples t test, and chi-square test. RESULTS: Twenty-two male and 30 female patients completed 1-year follow-up questionnaires. Mean ± SD follow-up time was 16.2 ± 3.1 months. The cohort had a mean age of 38.9 ± 9.3 years. Baseline radiographs demonstrated minimal arthritis (Tönnis grades 0-2). Mean alpha angle differed significantly between men and women at 52.9°± 8.6° and 46.3°± 8.5°, respectively. At 1-year follow-up, patients experienced a significant improvement in all 4 functional outcome measures (mHHS: 72.6 vs 81.8, HOS-Activities of Daily Living: 78.6 vs 86.4, HOS-Sports: 56.0 vs 71.1, iHOT-33: 47.5 vs 67.9). Patients with and without femoroacetabular impingement demonstrated a significant improvement in the mHHS. However, 48.1% reported no improvement in their pain; 69.2% were limited in their activities; and 40.4% were still considering surgery. Overall, 71.2% were satisfied with nonsurgical treatment. CONCLUSION: Patients with symptomatic labral tears can experience functional improvement after a minimum 1 year of nonsurgical treatment in the presence and absence of femoroacetabular impingement. However, many report residual pain, alteration of their activities, and interest in surgery. This information is important when patients are counseled in the treatment options for this injury. Identifying the population that responds best to nonsurgical management and comparing outcomes with those undergoing surgical management should be the focus of future research. Longer-term follow-up may be necessary to reevaluate pain, function, and return to activities.

Surgical treatment of displaced pediatric lateral condyle fractures of the humerus by the posterior approach.

The surgical approach for open reduction and internal fixation of lateral condyle fractures in children is controversial. Some authors recommend the lateral approach to the elbow over the posterior approach because of theoretical concern for injury to the vascular supply of the distal humerus and potential avascular necrosis (AVN). The purpose of this retrospective case series study is to report the outcomes of open reduction and internal fixation of displaced lateral condyle fractures of the humerus by the posterior approach. Fifteen consecutive cases were reviewed and the posterior approach resulted in minimal postoperative loss of motion, no angular deformity, cosmetic scars, and no AVN. We support that AVN occurs because of stripping of soft tissues from the lateral condyle fragment and not the approach used. Stripping of soft tissues is not required when using the posterior approach because of excellent visualization of the fracture reduction.

Effects of anterior offsetting of humeral head component in posteriorly unstable total shoulder arthroplasty: Finite element modeling of cadaver specimens.

A novel technique of "anterior offsetting" of the humeral head component to address posterior instability in total shoulder arthroplasty has been proposed, and its biomechanical benefits have been previously demonstrated experimentally. The present study sought to characterize the changes in joint mechanics associated with anterior offsetting with various amounts of glenoid retroversion using cadaver specimen-specific 3-dimensional finite element models. Specimen-specific computational finite element models were developed through importing digitized locations of six musculotendinous units of the rotator cuff and deltoid muscles based off three cadaveric shoulder specimens implanted with total shoulder arthroplasty in either anatomic or anterior humeral head offset. Additional glenoid retroversion angles (0°, 10°, 20°, and 30°) other than each specimen׳s actual retroversion were modeled. Contact area, contact force, peak pressure, center of pressure, and humeral head displacement were calculated at each offset and retroversion for statistical analysis. Anterior offsetting was associated with significant anterior shift of center of pressure and humeral head displacement upon muscle loading (p<0.05). Although statistically insignificant, anterior offsetting was associated with increased contact area and decreased peak pressure (p > 0.05). All study variables showed significant differences when compared between the 4 different glenoid retroversion angles (p < 0.05) except for total force (p < 0.05). The study finding suggests that the anterior offsetting technique may contribute to joint stability in posteriorly unstable shoulder arthroplasty and may reduce eccentric loading on glenoid components although the long term clinical results are yet to be investigated in future.

"In-Round" Labral Repair After Acetabular Recession Using Intermittent Traction.

The prevalence of hip arthroscopy has increased exponentially with the advent of arthroscopic labral repair techniques for femoroacetabular impingement. The goal of arthroscopic labral repair is to re-create the anatomic suction seal of the labrum against the femoral head. This important anatomic relationship has been demonstrated in several biomechanical studies. Performing the acetabular recession and evaluating the congruity of labral repairs during surgery is difficult with the application of traction distracting the femoral head from the chondrolabral junction. Additionally, prolonged traction risks nerve injury during hip arthroscopy. The purpose of this technique article is to describe a method of using traction only for central compartment work, and releasing the traction to allow the femoral head to reduce the labrum to its anatomic position for acetabular recession, anchor placement, and suture fixation. In this manner, the presented technique prevents an "out-of-round" or everted repair. This technique re-creates the native anatomy and biomechanics of the hip after acetabular recession and labral repair while decreasing traction time.

Puncture Capsulotomy During Hip Arthroscopy for Femoroacetabular Impingement: Preserving Anatomy and Biomechanics.

We describe an arthroscopic technique for the treatment of labral pathology and femoroacetabular impingement that provides excellent access to the central and peripheral compartments while preserving the biomechanically crucial components of hip joint stability. The hip capsule and the ligaments within it have been shown to be integral to hip biomechanical stability. Other popular techniques such as interportal and T-capsulotomy inherently damage the capsuloligamentous complex of the hip and can be associated with postoperative gross instability, micro-instability, heterotopic ossification, and seroma. Capsular closure may mitigate some of these effects but has been associated with capsular insufficiency and requires postoperative restrictions that can be prolonged. Our surgical technique focuses on careful portal placement, replacement when necessary, use of a switching stick to maximize peripheral compartment visualization, and joint access in the most minimally invasive manner while avoiding complications associated with extended capsulotomy. The objective of this Technical Note is to describe a technique by which full access to the joint can be obtained while not disrupting the biomechanics of the joint capsule.

Biomechanical benefits of anterior offsetting of humeral head component in posteriorly unstable total shoulder arthroplasty: A cadaveric study.

Restoration of joint stability during total shoulder arthroplasty can be challenging in the face of severe glenoid retroversion. A novel technique of humeral head component anterior-offsetting has been proposed to address posterior instability. We evaluated the biomechanical benefits of this technique in cadaveric specimens. Total shoulder arthroplasty was performed in 14 cadaveric shoulders from 7 donors. Complementary shoulders were assigned to either 10° or 20° glenoid retroversion, with retroversion created by eccentric reaming. Two humeral head component offset positions were tested in each specimen: The anatomic (posterior) and anterior (reverse). With loads applied to the rotator cuff and deltoid, joint contact pressures and the force and energy required for posterior humeral head translation were measured. The force and energy required to displace the humeral head posteriorly increased significantly with the anterior offset position compared to the anatomic offset position. The joint contact pressures were significantly shifted anteriorly, and the joint contact area significantly increased with the anterior offset position. Anterior offsetting of the humeral head component increased the resistance to posterior humeral head translation, shifted joint contact pressures anteriorly, and increased joint contact area, thus, potentially increasing the joint stability in total shoulder arthroplasty with simulated glenoid retroversion.