Primary and revision reverse total shoulder arthroplasty using a patient-matched glenoid implant for severe glenoid bone deficiency.

BACKGROUND: Severe glenoid bone loss in the setting of both primary and revision reverse total shoulder arthroplasty (rTSA) continues to remain a significant challenge. The purpose of this study was to report on radiographic and clinical outcomes of primary and revision rTSA using a patient-matched, 3-dimensionally printed metal glenoid implant to address severe glenoid bone deficiency. This is a follow-up study to previously reported preliminary results. METHODS: A retrospective review was performed on 62 patients with severe glenoid bone deficiency who underwent either primary or revision rTSA using the Comprehensive Vault Reconstruction System (VRS) (Zimmer Biomet) at a single institution. Preoperative and postoperative values for the Disabilities of the Arm, Shoulder and Hand (DASH), Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Simple Shoulder Test (SST), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain scores as well as active range of motion (ROM) were collected and compared using the Wilcoxon signed rank test with the level of statistical significance set at P < .05. The percentage of patients achieving minimal clinically important difference (MCID) and substantial clinical benefit (SCB) was also calculated. RESULTS: Fifty-five of 62 shoulders (88.7%) were able to be contacted at a minimum of 2 years postoperatively, with 47 of 62 (75.8%) having complete clinical and radiographic follow-up with a mean age of 67.5 years (range, 48-85 years) and follow-up of 39.2 months (range, 25-56 months). There were 19 primary and 28 revision rTSAs. Significant improvements were seen in mean active forward flexion (63.1° ± 30.3° to 116.8° ± 35°), abduction (48.1° ± 16.1 to 76.2° ± 13.4°) (P < .001), external rotation (16° ± 23.7° to 32.1° ± 24.5°) (P < .005), DASH (59.9 ± 17.7 to 35.7 ± 24.3), Constant (23.4 ± 13.1 to 53.1 ± 17.4), ASES (27.8 ± 16.2 to 69.1 ± 25.2), SST (3.3 ± 2.5 to 7.6 ± 3.5), SANE (28.9 ± 18.3 to 66.7 ± 21.2), and VAS pain (7.1 ± 2.4 to 1.8 ± 2.6) scores (P < .001). MCID and SCB was achieved in a majority of patients postoperatively. The overall complication rate was 29.1%, with only 1 baseplate failure. CONCLUSION: This study demonstrates promising evidence that the VRS implant can be used as a viable option to achieve clinically important improvement in a majority of patients treated for severe glenoid bone deficiency with rTSA in both the primary and revision setting.

Central fixation element type and length affect glenoid baseplate micromotion in reverse shoulder arthroplasty.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is commonly used to treat patients with rotator cuff tear arthropathy. Loosening of the glenoid component remains one of the principal modes of failure and represents a significant complication that requires revision surgery. This study assessed the effects of various factors on glenoid baseplate micromotion for primary fixation of RSA. MATERIALS AND METHODS: A half-fractional factorial design of experiment was used to assess 4 factors: central element type (central peg or screw), central cortical engagement according to length (13.5 or 23.5 mm), anterior-posterior peripheral screw type (nonlocking or locking), and cancellous bone surrogate density (160 or 400 kg/m3, 10 or 25 PCF). Glenoid baseplates were implanted into high- or low-density Sawbones rigid polyurethane foam blocks and cyclically loaded at 60° for 1000 cycles (500-N compressive force range) using a custom-designed loading apparatus. Micromotion at the 4 peripheral screw positions was recorded using linear variable differential transformers. RESULTS: Central peg fixation generated 358% greater micromotion at all peripheral screw positions compared with central screw fixation (P < .001). Baseplates with short central elements that lacked cortical bone engagement generated 328% greater micromotion than those with long central elements (P = .001). No significant effects were observed when varying anterior-posterior peripheral screw type or bone surrogate density. There were significant interactions between central element type and length (P < .001). DISCUSSION: A central screw and a long central element that engaged cortical bone reduced RSA baseplate micromotion. These findings serve to inform surgical decision making regarding baseplate fixation elements to minimize the risk of glenoid loosening and, thus, the need for revision surgery.

Early results of reverse total shoulder arthroplasty using a patient-matched glenoid implant for severe glenoid bone deficiency.

BACKGROUND: Reverse total shoulder arthroplasty (rTSA) in the presence of significant glenoid bone loss remains a challenge. This study presents preliminary clinical and radiographic outcomes of primary and revision rTSA using a patient-matched, 3-dimensionally printed custom metal glenoid implant to address severe glenoid bone deficiency. METHODS: Between September 2017 and November 2018, 19 patients with severe glenoid bone deficiency underwent primary (n = 9) or revision rTSA (n = 10) using the Comprehensive Vault Reconstruction System (VRS) (Zimmer Biomet, Warsaw, IN, USA) at a single institution. Preoperative and postoperative values for the Disabilities of the Arm, Shoulder and Hand score, Constant score, American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, Single Assessment Numeric Evaluation score, and visual analog scale pain score and active range of motion were compared using the Wilcoxon signed rank test with the level of statistical significance set at P < .05. RESULTS: Complications occurred in 4 patients (21%), including a nondisplaced greater tuberosity fracture treated conservatively in 1, intraoperative cortical perforation during humeral cement removal treated with an allograft strut in 1, and recurrent instability and hematoma formation treated with humeral component revision in 1. One patient with an early periprosthetic infection was treated with component removal and antibiotic spacer placement at an outside facility and was subsequently lost to follow-up. Eighteen patients with 1-year minimum clinical and radiographic follow-up were evaluated (mean, 18.2 months; range, 12-27 months). Significant improvements were noted in the mean Disabilities of the Arm, Shoulder and Hand score (57.4 ± 16.5 vs. 29.4 ± 19.5, P < .001), mean Constant score (24.6 ± 10.2 vs. 60.4 ± 14.5, P < .001), mean American Shoulder and Elbow Surgeons score (32 ± 18.2 vs. 79 ± 15.6, P < .001), mean Simple Shoulder Test score (4.5 ± 2.6 vs. 9.3 ± 1.8, P < .001), mean Single Assessment Numeric Evaluation score (25.4 ± 13.7 vs. 72.2 ± 17.8, P < .001), mean visual analog scale pain score (6.2 ± 2.9 vs. 0.7 ± 1.3, P < .001), mean active forward flexion (53° ± 27° vs. 124° ± 23°, P < .001), and mean active abduction (42° ± 17° to 77° ± 15°, P < .001). Mean external rotation changed from 17° ± 19° to 32° ± 24° (P = .06). No radiographic evidence of component loosening, scapular notching, or hardware failure was observed at last follow-up in any patient. CONCLUSION: The preliminary results of rTSA using the VRS to manage severe glenoid bone deficiency are promising, but longer follow-up is necessary to determine the longevity of this implant.

Treatment of severe glenoid deficiencies in reverse shoulder arthroplasty: the Glenius Glenoid Reconstruction System experience.

BACKGROUND: The treatment of glenoid bone deficiencies in primary or revision total shoulder arthroplasty is challenging. This retrospective study evaluated the short-term clinical and radiologic results of a new custom-made patient-specific glenoid implant. METHODS: We treated 10 patients with severe glenoid deficiencies with the Glenius Glenoid Reconstruction System (Materialise NV, Leuven, Belgium). Outcome data included a patient-derived Constant-Murley score, a visual analog score (VAS), a satisfaction score, the 11-item version of the Disabilities of the Arm, Shoulder and Hand score, and the Simple Shoulder Test. We compared the postoperative position of the implant with the preoperative planned position on computed tomography scans. RESULTS: At an average follow-up period of 30.5 months, the mean patient-derived Constant-Murley score was 41.3 ± 17.5 points (range, 18-76 points) with a visual analog scale of 3.3 ± 2.5 points (range, 0-7 points). The mean 11-item version of the Disabilities of the Arm, Shoulder and Hand score was 35.8 ± 18.4 (range, 2-71), and the mean Simple Shoulder Test was 47.5% ± 25.3% (range, 8%-92%). Eight patients reported the result as better (n = 3) or much better (n = 5). One patient had an elongation of the brachial plexus, and 1 patient had a period of instability. The average preoperative glenoid defect size was 9 ± 4 cm3 (range, 1-14 cm3). The mean deviation between the preoperative planned and the postoperative version and inclination was 6° ± 4° (range 1°-16°) and 4° ± 4° (range 0°-11°), respectively. CONCLUSION: Early results of the Glenius Glenoid Reconstruction System are encouraging. Adequate pain relief, a reasonable functionality, and good patient satisfaction can be obtained in these difficult cases. Further follow-up will determine the bony ingrowth and subsequent longevity of this patient-specific glenoid component.

Healing and functional outcome of a subscapularis peel repair with a stem-based repair after total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to evaluate functional outcome and healing of a subscapularis peel with a stem-based repair after total shoulder arthroplasty (TSA). The hypothesis was that the repair would lead to subscapularis healing in the majority of cases. METHODS: A prospective analysis was performed on a consecutive series of TSAs. Range of motion and functional outcome were assessed according to American Shoulder and Elbow Surgeons, Single Assessment Numeric Evaluation, Simple Shoulder Test, and visual analog scale scores at a minimum follow-up of 1 year. Belly-press and lift-off tests were also performed. An ultrasound evaluation assessed subscapularis healing at final follow-up. RESULTS: At a mean follow-up of 15 months, 60 patients (mean age, 64 years) were examined. Mean forward flexion improved from 115° to 137°. External rotation at the side improved from 27° to 52°, and internal rotation improved from L4 to L2 (P < .05). American Shoulder and Elbow Surgeons score improved from 34.3 to 79.8 (P < .001). Likewise, the Single Assessment Numeric Evaluation and Simple Shoulder Test scores showed significant improvement from 33.1 to 85.3 and 4.3 to 10.2, respectively (P < .001). The visual analog scale score for pain decreased from 5.8 to 0.7 (P < .001). On ultrasound examination, the subscapularis was healed intact in 55 cases (91.7%), attenuated in 3 cases (5%), and torn in 2 cases (3.3%). CONCLUSION: A stem-based repair of a subscapularis peel after TSA leads to functional improvement in the majority of cases with >90% postoperative healing of the subscapularis.

Primary shoulder arthroplasty using a custom-made hip-inspired implant for the treatment of advanced glenohumeral arthritis in the presence of severe glenoid bone loss.

BACKGROUND: Total shoulder arthroplasty for end-stage glenohumeral arthritis with severe glenoid bone loss poses a unique challenge for shoulder surgeons. Current surgical solutions are limited and associated with high complication rates. We hypothesized that a custom-made computer-aided design-computer-aided manufacturing (CAD-CAM) total shoulder replacement (TSR; Stanmore Implants Worldwide, Elstree, UK) resembling a total hip prosthesis could offer a reliable alternative for this challenging subset of patients. METHODS: Thirty-seven patients with rotator cuff-deficient end-stage glenohumeral arthritis and severe glenoid bone loss (assessed as not amenable to treatment with standard anatomic or reverse total shoulder implants) were treated with the CAD-CAM TSR between 2006 and 2013. Clinical data were collected prospectively and analyzed at a mean follow-up of 5 years. RESULTS: Postoperatively, the pain level with activity decreased from 9.2 ± 1.7 to 2.4 ± 2.9 (P < .001). The Oxford Shoulder Score improved from 11 ± 8 points to 27 ± 11 points (P < .001), and the Subjective Shoulder Value (on a 0%-100% scale) improved from 23% ± 14% to 60% ± 24% (P < .001). Active forward elevation improved from 39° ± 23° to 63° ± 38° (P < .001), and external rotation improved from 6° ± 16° to 15° ± 17° (P = .001). Component revision was required in 6 of 37 patients (16%) (glenoid loosening in 1, humeral stem loosening in 3, periprosthetic fracture in 1, and prosthesis dislocation in 1). CONCLUSION: The CAD-CAM TSR offers a reliable alternative for the treatment of end-stage glenohumeral arthritis with severe glenoid deficiency not amenable to standard anatomic or reverse total shoulder implants, with maintenance of significant pain relief and clinical-functional improvement at 5-year postoperative follow-up.

Clindamycin Efficacy for Cutibacterium acnes Shoulder Device-Related Infections.

Clindamycin is an antibiotic with high bioavailability and appropriate bone diffusion, often proposed as an alternative in guidelines for C. acnes prosthetic joint infections. We aimed to evaluate the efficacy of clindamycin in the treatment of C. acnes shoulder implant joint infections (SIJI). METHODS: A retrospective analysis was conducted at the University Hospital of Nice (France) between 2010 and 2019. We included patients with one shoulder implant surgical procedure and at least one C. acnes positive sample. We selected the C. acnes SIJI according to French and international recommendations. The primary endpoint was favorable outcome of C. acnes SIJI treatment after at least 1-year follow-up in the clindamycin group compared to another therapeutic group. RESULTS: Forty-eight SIJI were identified and 33 were treated with clindamycin, among which 25 were treated with monotherapy. The median duration of clindamycin antibiotherapy was 6 weeks. The average follow-up was 45 months; one patient was lost to follow-up. Twenty-seven patients out of 33 (82%) were cured with clindamycin, compared to 9/12 (75%) with other antibiotics. The rate of favorable outcomes increased to 27/31 (87%) with clindamycin and to 9/10 (90%) for other antibiotics when no septic revision strategies were excluded (P = 1.00). CONCLUSIONS: The therapeutic strategy based on one- or two-stage revision associated with 6 weeks of clindamycin seems to be effective.

Artificial Intelligence-Based Solution in Personalized Computer-Aided Arthroscopy of Shoulder Prostheses.

BACKGROUND: Early recognition of prostheses before reoperation can reduce perioperative morbidity and mortality. Because of the intricacy of the shoulder biomechanics, accurate classification of implant models before surgery is fundamental for planning the correct medical procedure and setting apparatus for personalized medicine. Expert surgeons usually use X-ray images of prostheses to set the patient-specific apparatus. However, this subjective method is time-consuming and prone to errors. METHOD: As an alternative, artificial intelligence has played a vital role in orthopedic surgery and clinical decision-making for accurate prosthesis placement. In this study, three different deep learning-based frameworks are proposed to identify different types of shoulder implants in X-ray scans. We mainly propose an efficient ensemble network called the Inception Mobile Fully-Connected Convolutional Network (IMFC-Net), which is comprised of our two designed convolutional neural networks and a classifier. To evaluate the performance of the IMFC-Net and state-of-the-art models, experiments were performed with a public data set of 597 de-identified patients (597 shoulder implants). Moreover, to demonstrate the generalizability of IMFC-Net, experiments were performed with two augmentation techniques and without augmentation, in which our model ranked first, with a considerable difference from the comparison models. A gradient-weighted class activation map technique was also used to find distinct implant characteristics needed for IMFC-Net classification decisions. RESULTS: The results confirmed that the proposed IMFC-Net model yielded an average accuracy of 89.09%, a precision rate of 89.54%, a recall rate of 86.57%, and an F1.score of 87.94%, which were higher than those of the comparison models. CONCLUSION: The proposed model is efficient and can minimize the revision complexities of implants.

Baseplate Options for Reverse Total Shoulder Arthroplasty.

PURPOSE OF REVIEW: Baseplate fixation has been known to be the weak link in reverse total shoulder arthroplasty (RTSA). A wide variety of different baseplates options are currently available. This review investigates the recent literature to present the reader with an overview of the currently available baseplate options and modes of fixation. RECENT FINDINGS: The main elements that differentiate baseplates are the central fixation element, the size of the baseplate, the shape, the backside geometry, whether or not an offset central fixation exists, the number of peripheral screws, and the availability of peripheral augmentation. The wide array of baseplate options indicates that no particular design has proven superiority. As such, surgeons should be aware of their options and choose an implant that the surgeon is comfortable with and one that best suits the individual patient anatomy. With the growing number of RTSA procedures and registries with long-term follow-up, future investigations will hopefully delineate the ideal baseplate design to optimize survivorship.

Reverse shoulder arthroplasty has higher perioperative implant complications and transfusion rates than total shoulder arthroplasty.

BACKGROUND: Indications for reverse total shoulder arthroplasty (RTSA) have expanded. The purpose of this retrospective cohort study was to evaluate national trends in shoulder arthroplasty utilization and to compare national perioperative complication rates for hemiarthroplasty (HA), total shoulder arthroplasty (TSA), and RTSA in a matched cohort. METHODS: The National Inpatient Sample was queried from 2011-2013 to identify patients who underwent HA, TSA, or RTSA. Age, sex, race, insurance type, Elixhauser comorbidity index, and perioperative complications were identified. A coarsened exact matching algorithm was used to match RTSA patients with TSA and HA patients to compare medical and implant-related perioperative in-hospital complications. Multivariable logistic regression analysis was performed on unmatched data to identify risk factors for development of perioperative complications. RESULTS: Overall, 42,832 shoulder arthroplasties were identified (44% TSAs, 34% RTSAs, 19% HAs). After matching, RTSAs had 6.2 times the odds of a perioperative implant-related complication (P < .001) and 2 times the odds of a red blood cell transfusion compared with TSAs (P < .001). The logistic regression model showed that prior shoulder arthroplasty (odds ratio [OR], 15.1; P < .001), younger age (OR, 0.98; P = .006), earlier year of index surgery (OR, 0.83; P = .002), history of illicit drug use (OR, 6.2; P = .008), and depression (OR, 2.3; P = .003) were risk factors for development of in-hospital implant-related complications after RTSA. CONCLUSION: The perioperative implant-related complication rate and postoperative transfusion rate of RTSAs were significantly higher than those of TSAs. In addition, prior shoulder surgery, younger age, earlier year of index surgery, history of illicit drug use, and depression were risk factors for implant-related complications after RTSA. However, the perioperative RTSA implant-related complications did decline each year, suggesting a growing national proficiency with performing RTSA.

Reverse shoulder arthroplasty for type 1 sequelae of a fracture of the proximal humerus.

Aims: The aim of this study was to analyze the results of reverse shoulder arthroplasty (RSA) in patients with type 1 sequelae of a fracture of the proximal humerus in association with rotator cuff deficiency or severe stiffness of the shoulder. Patients and Methods: A total of 38 patients were included: 28 women and ten men. Their mean age at the time of arthroplasty was 73 years (54 to 91). Before the RSA, 18 patients had been treated with open reduction and internal fixation following a fracture. A total of 22 patients had a rotator cuff tear and 11 had severe stiffness of the shoulder with < 0° of external rotation. The mean follow-up was 4.3 years (1.5 to 10). The Constant score and the range of movement of the shoulder were recorded preoperatively and at final follow-up. Preoperatively, radiographs in two planes were performed, as well as CT or arthro-CT scans; radiographs were also performed at final follow-up. Results: The mean Constant score improved from 25 points (5 to 47) preoperatively to 57 points (15 to 81) postoperatively. The mean forward elevation of the shoulder increased from 73° (10° to 130°) preoperatively to 117° (15° to 170°) postoperatively. Previous surgery did not influence the outcome. Patients with rotator cuff tears had lower Constant scores than patients without (p = 0.037). Those with preoperative stiffness of the shoulder had lower postoperative external rotation compared with patients without stiffness (p = 0.046). There was no radiographic evidence of loosening. Three complications occurred, leading to revision surgery in two patients. In all, 17 patients rated their result as very good (45%), another 17 as good (45%), two as satisfactory (5%), and two as unsatisfactory (5%). Discussion: RSA is an effective form of treatment for patients with type 1 sequelae of a fracture of the proximal humerus associated with rotator cuff deficiency or stiffness of the shoulder, with high rates of satisfaction. Rotator cuff tears and stiffness of the shoulder had an adverse effect on the clinical outcome. Cite this article: Bone Joint J 2018;100-B:318-23.