Revision arthroplasty with a hip-inspired computer-assisted design/computer-assisted manufacturing implant for glenoid-deficient shoulders

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.

Patient-specific implants in reverse shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) is widely popular among shoulder surgeons and patients, and its prevalence has increased dramatically in recent years. With this increased use, the indicated pathologies associated with RTSA are more likely to be encountered, and challenging patient presentations are more likely to be seen. One prominent challenging presentation is RTSA patients with severe glenoid bone loss. Several techniques with varying degrees of invasiveness, including excessive reaming, alternate centerline, bone grafting, and patient-specific implants (PSIs), have been developed to treat patients with this presentation. PSI treatment uses a three-dimensional reconstruction of a computed tomography scan to design a prosthetic implant or component customized to the patient's glenoid morphology, allowing compensation for any significant bone loss. The novelty of this technology implies a paucity of available literature, and although many studies show that PSIs have good potential for solving challenging shoulder problems, some studies have reported questionable and equivocal outcomes. Additional research is needed to explore the indications, outcomes, techniques, and cost-efficiency of this technology to help establish its role in current treatment guidelines and strategies.

Hemi-reverse revision arthroplasty in the setting of severe glenoid bone loss

BACKGROUND

Glenoid bone loss is one of the main challenges in revision of failed shoulder arthroplasties. The concept of a hemi-reverse procedure is to implant a glenoid baseplate and glenosphere to protect the glenoid reconstruction to allow it to heal and to preserve the joint space for a potential second-stage humeral component implantation. The purpose of this study was to report the results of hemi-reverse procedures.

METHODS

Revision to a hemi-reverse procedure was performed in 15 patients: 8 with a failed anatomic total shoulder arthroplasty, 3 with a failed reverse shoulder arthroplasty, 3 with a failed humeral hemiarthroplasty, and 1 with placement of a cement spacer owing to sepsis after a total shoulder arthroplasty. After complete removal of the initial prosthesis, all patients underwent glenoid reconstruction with bone grafting and implantation of a reverse arthroplasty baseplate and glenosphere. A humeral implant was not placed in any case. The patients were prospectively followed up and underwent complete clinical and radiologic studies preoperatively and postoperatively at a minimum of 2 years after the surgical procedure.

RESULTS

Thirteen hemi-reverse implants and glenoid bone grafts healed (86%) and remained radiographically stable. One hemi-reverse construct migrated and became mechanically loose, which was attributed to absent fixation of the central post in the native glenoid bone. In 1 patient, an implant-related infection developed; irrigation and debridement were performed, in addition to revision to a resection arthroplasty. After documented radiographic healing of the hemi-reverse glenoid reconstruction, 5 patients underwent a second-stage revision to a reverse procedure with insertion of a humeral component at a median of 6 months (interquartile range [IQR], 6-8 months). In this group, the median follow-up period was 73 months (IQR, 45-153 months), the median Constant score was 48 (IQR, 41-56), median active forward elevation was 135° (IQR, 100°-150°), and the median Subjective Shoulder Value was 50% (IQR, 50%-60%). In the group of 9 patients with remaining hemi-reverse implants, the median follow-up period was 38 months (IQR, 29-60 months), the median Constant score was 41 (IQR, 38-46), median active forward elevation was 100° (IQR, 80°-100°), and the median Subjective Shoulder Value was 50% (IQR, 40%-60%).

CONCLUSION

The hemi-reverse procedure is an effective revision procedure to reconstruct a severely deficient glenoid. The hemi-reverse procedure may function as the definitive procedure, with satisfactory outcomes. Additionally, in patients who undergo the hemi-reverse procedure, second-stage revision to a total reverse procedure can be performed once imaging confirms bone graft and construct stability.

Short-term outcomes of reverse shoulder arthroplasty using a custom baseplate for severe glenoid deficiency

HYPOTHESIS AND BACKGROUND

Complex glenoid bone loss and deformity present a challenge for the shoulder arthroplasty surgeon. Eccentric reaming, bone grafting, augmented glenoid components, and salvage hemiarthroplasty are common strategies for managing these patients. The glenoid vault reconstruction system (VRS; Zimmer-Biomet) is a novel solution for both primary and revision arthroplasty using a custom glenoid baseplate. We hypothesized that patients undergoing reverse shoulder arthroplasty (RSA) with VRS would have acceptable short-term outcomes and complication rates.

METHODS

Patients who underwent RSA with VRS for severe glenoid deformity or bone loss by one of 4 board-certified, fellowship-trained shoulder and elbow surgeons at 3 academic tertiary referral centers between September 2015 and November 2018 were eligible for inclusion. Patient data were obtained via medical record review and telephone questionnaires. The Numeric Pain Rating Scale (NPRS), Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Penn Shoulder Scores, and range of motion (ROM) measurements were obtained pre- and postoperatively. Radiographs were reviewed at final follow-up for evidence of component loosening or hardware failure. Any complication was documented. Outcomes were compared using Wilcoxon signed-rank tests with P <. 05 considered significant.

RESULTS

Twelve shoulders (11 patients) were included with a mean age of 68 years; 7 were primary arthroplasties and 5 were revisions. At an average follow-up time of 30 months, median improvement in NPRS score was 7 points, SANE score 43%, ASES score 45 points, and Penn Shoulder Score 49 points. There were statistically significant improvements in median ROM measurements (forward elevation 20°, external rotation 40°, internal rotation 2 spinal levels). At final follow-up, all implants were radiographically stable without loosening. There were no complications.

DISCUSSION AND CONCLUSION

This study demonstrates that RSA using the custom VRS glenoid implant is a safe and effective technique addressing complex glenoid deformity or bone loss in both primary and revision settings. At short-term follow-up, all patient-reported outcomes and ROM measures improved significantly, and there were no complications. Future work should determine mid- and long-term outcomes, preferably in a prospective manner with defined patient populations.

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.

Revision shoulder arthroplasty: a systematic review and comparison of North American vs. European outcomes and complications

BACKGROUND

Joint registries provide invaluable data on primary arthroplasties with revision as the endpoint; however, the revision outcomes are often excluded. Therefore, a PROSPERO registered review (CRD42015032531) of all revision studies in North America and Europe was conducted to evaluate demographics, etiologies and indications, implant manufacturer, and complications by geographic region.

METHODS

The MEDLINE, EMBASE, and CENTRAL databases were searched for revision arthroplasty clinical studies with a minimum mean 24-month follow-up. There were no language exclusions. Articles published in German, French, and Italian were reviewed by research personnel proficient in each language.

RESULTS

The mean age at revision was 66 ± 5 years (male = 759, female = 1123). The male-female ratio in North American and Europeans studies was 43:57 and 34:66, respectively. The most common etiology for primary surgery in both regions was osteoarthritis or glenoid arthrosis (38%). The most common revision indication overall was rotator cuff tear, deficiency, or arthropathy (26%). The most common implant type used in revisions was a reverse shoulder arthroplasty (54%). The complication rate for all revisions was 17%. There were a total of 465 complications, and of those, 74% lead to a reoperation.

CONCLUSION

Generally, shoulder arthroplasties are designed to last 10-15 years; however, revisions are being performed at a mean 3.9 years from the primary procedure, based on the published studies included in this systematic review. Additionally, of the complications, a large number (74%) went on to a reoperation. Further insight into the reasons for early revisions and standardized reporting metrics and data collection on revisions is needed.

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.