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BACKGROUND: Periprosthetic shoulder infection (PSI) remains a devastating complication after reverse shoulder arthroplasty (RSA). Currently, scientific data related to the management of PSI are limited, and the optimal strategy and related clinical outcomes remain unclear. Guidelines from the Infectious Diseases Society of America for the management of periprosthetic joint infection are mainly based on data from patients after hip and knee arthroplasty. The aim of this study was to evaluate whether these guidelines are also valid for patients with PSI after RSA. In addition, the functional outcome according to the surgical intervention was assessed. METHODS: An RSA database was retrospectively reviewed to identify infections after primary and revision RSAs, diagnosed between 2004 and 2018. Data collected included age, sex, indication for RSA, causative pathogen, surgical and antimicrobial treatment, functional outcome, and recurrence. RESULTS: Thirty-six patients with a PSI were identified. Surgical treatment was subdivided into débridement and implant retention (DAIR) (n = 6, 17%); 1-stage revision (n = 1, 3%); 2-stage revision (n = 16, 44%); multiple-stage revision (>2 stages) (n = 7, 19%); definitive spacer implantation (n = 2, 6%); and resection arthroplasty (n = 4, 11%). The most common causative pathogens were Staphylococcus epidermidis (n = 11, 31%) and Cutibacterium acnes (n = 9, 25%). Recurrence was diagnosed in 4 patients (11%), all of whom were initially treated with a DAIR approach. The median follow-up period was 36 months (range, 24-132 months). CONCLUSION: PSI is typically caused by low-virulence pathogens, which often are diagnosed with a delay, resulting in chronic infection at the time of surgery. Our results indicate that treatment of patients with chronic PSI with DAIR has a high recurrence rate. In addition, implant exchange (ie, 1- and 2-stage exchange) does not compromise the functional result as compared with implant retention. Thus, patients with chronic PSI should be treated with implant exchange. Future research should further clarify which surgical strategy (ie, 1-stage vs. 2-stage exchange) has a better outcome overall. ispartof: JOURNAL OF SHOULDER AND ELBOW SURGERY vol:30 issue:11 pages:2514-2522 ispartof: location:United States status: published

Shoulder osteoarthritis can be divided into different glenoid types (A, B, C, and D) and subtypes. The aim of this study was to investigate if there is an association between the prearthropathy scapular anatomy, shoulder osteoarthritis, and different glenoid types and subtypes.Using principal components analysis, a statistical shape model (SSM) of the scapula was constructed from a data set of 110 computed tomographic (CT) scans. These subjects formed the control group. Next, CT scan images of 117 patients with osteoarthritis were classified according to the modified Walch classification. A complete 3-dimensional (3D) scapular bone model was created for every patient, and using the SSM, a reconstruction of their prearthropathy scapular anatomy was performed. Automated 3D measurements were performed in both the patient and control group to obtain glenoid version and inclination, critical shoulder angle (CSA), posterior acromial slope (PAS), lateral acromion angle, scapular offset, and the rotational alignment of the coracoacromial complex. These parameters were compared between controls, patients with osteoarthritis, and glenoid types and subtypes.Mean version and inclination for the control group was 6° retroversion and 8° superior inclination (both SD 4°). The mean CSA, PAS, coracoid-posterior acromion angle, posterior acromion-scapular plane angle, and fulcrum axis ratio were 30° (SD 4°), 64° (SD 8°), 116° (SD 9°), 55° (SD 7°), and 46% (SD 4%), respectively. Patients with osteoarthritis had a significant lower CSA, posterior acromion-scapular plane angle, coracoid-posterior acromion angle, and fulcrum axis ratio (27°, 50°, 111°, and 44%, all P.001). We found a significant difference between the control group and the respective glenoid types for the following parameters: mean CSA and coracoid-posterior acromion angle for A glenoids (27°, P = .001, and 111°, P = .007); mean version, CSA, PAS, coracoid-posterior acromion angle, posterior acromion-scapular plane angle, and fulcrum axis ratio for B glenoids (11°, 27°, 71°, 111°, 49°, and 43%, all P .001); and mean version, CSA, and posterior acromion-scapular plane angle for D glenoids (2°, P = .002, 26°, P = .003, and 48°, P = .007).There seems to be an association between prearthropathy scapular anatomy and shoulder osteoarthritis. A small lateral extension and less posterior rotation of the acromion is associated with shoulder osteoarthritis and is present in almost all types and subtypes of glenoid morphology. Furthermore, B and D glenoids are associated with, respectively, a more and less pronounced prearthropathy glenoid retroversion.

Background Assessment of glenoid bone defects is important to select the optimal glenoid component design during shoulder arthroplasty planning and implantation. This study presents a fully automated method to describe glenoid bone loss using 3-dimensional measurements without the need for a healthy contralateral reference scapula. Methods The native shape of the glenoid is reconstructed by fitting a statistical shape model (SSM) of the scapula. The total vault loss percentage, local vault loss percentages, defect depth, defect area percentage, and subluxation distance and region are computed based on a comparison of the reconstructed and eroded glenoids. The method is evaluated by comparing its results with a contralateral bone–based reconstruction approach in a data set of 34 scapula and humerus pairs with unilateral glenoid bone defects. Results The SSM-based defect measurements deviated from the contralateral bone–based measurements with mean absolute differences of 5.5% in the total vault loss percentage, 4.5% to 8.0% in the local vault loss percentages, 1.9 mm in the defect depth, 14.8% in the defect area percentage, and 1.6 mm in the subluxation distance. The SSM-based method was statistically equivalent to the contralateral bone–based method for all parameters except the defect area percentage. Conclusion The presented method is able to automatically analyze glenoid bone defects using 3-dimensional measurements without the need for a healthy contralateral bone.

Background An important reason for failure of anatomic total shoulder arthroplasty is glenoid component loosening. We investigated the effect of backside bone support on the risk of failure of a glenoid component. Methods A finite element model was developed. Virtual surgery was performed for 2 types of glenoid components (cemented all polyethylene [PE] vs. metal backed [MB]), both with gradually decreasing backside bone support. Both bone failure and fixation failure were analyzed. The percentages of bone failure and fixation failure in terms of the critical cement volume (CCV) and micromotion-threshold percentage ratio (MTPR) for the PE and MB components, respectively, were defined and compared. Results For the reference PE model, the percentages of bone failure and fixation failure (CCV) were 17% and 34%, respectively. With eccentric loading for the MB component, the percentages of bone failure and fixation failure (MTPR) were 6% and 3%, respectively. A global increase in failure was observed with decreasing bone support. The increase in fixation failure, starting from the reference values (MTPR vs. CCV), was relatively more pronounced for the MB component (136% vs. 128%). Discussion Decreasing backside bone support for an anatomic glenoid component leads to an increased risk of fixation and bone failure. For PE components, decreasing backside support to 95% bone support had only a limited effect. In the case of an MB component, we noticed an increase in micromotion and bone failure already starting from 97% bone support. We conclude that an anatomic glenoid component should always be implanted while maximizing backside bone support.

Hypothesis: The contralateral scapula can be used as a reliable template to determine scapular offset, glenoid inclination, and version of the native scapula in view of reconstructing pathologic scapulae. Methods: Three-dimensional measurements of scapular offset, inclination, and version were performed using data from a set of 50 bilateral computed tomography scans of full scapulae to determine direct side-to-side differences. Results: The scapula pairs had a mean bilateral difference of 2 mm in offset, 2 degrees in inclination, and 2 degrees in version. Ninety percent of the scapula pairs showed an offset difference smaller than 3 mm. In 96% and 94% of the scapula pairs, the inclination difference and version difference, respectively, were smaller than 5 degrees. The maximum bilateral difference for offset, inclination, and version was 6 mm, 6 degrees, and 8 degrees, respectively. Discussion and Conclusion: The anatomic parameters of scapular offset, glenoid inclination, and version are quite symmetrical and fall into the currently technically feasible accuracy of shoulder arthroplasty implantation. The healthy scapula can be used as a template to guide the reconstruction of the glenoid during shoulder arthroplasty planning in the case of unilateral advanced arthropathy. (C) 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Arthroscopic needling of a rotator cuff calcification is a highly reliable operation in terms of pain relief and return of function. However, during the needling process, a cuff defect is created. Little is known about the evolution of this defect.We conducted a prospective, randomized controlled clinical trial to investigate the evolution of the aforementioned defect and the role of platelet-rich plasma (PRP) augmentation in this healing process. Patients were randomized to either group 1 (PRP, n = 20) or group 2 (no PRP [control group], n = 20). Patients in group 1 received a perioperative PRP infiltration at the rotator cuff defect, whereas the control group did not. Patients were assessed clinically preoperatively and postoperatively at 6 weeks, 3 and 6 months, and 1 year. The Constant score, Simple Shoulder Test, and QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) were used as outcome measures. The evolution of the cuff defect was evaluated on sonography at 3 and 6 months and with magnetic resonance imaging after 1 year.All patients improved significantly after surgery (P .05). There was no difference in clinical outcome or rotator cuff healing between groups. We observed a high rate of persistent rotator cuff defects after 1 year in both groups. The presence of residual cuff defects did not influence the clinical outcome.Arthroscopic needling is an operation with a predictive, good clinical outcome. We found a high rate of persistent rotator cuff defects after 1 year. This study could not identify any beneficial effect of the addition of PRP on rotator cuff healing.Level II; Randomized Controlled Trial; Treatment Study.