Dataset Information

Factors Influencing Acromial and Scapular Spine Strain after Reverse Total Shoulder Arthroplasty: A Systematic Review of Biomechanical Studies.

ABSTRACT:

Background

Acromial and scapular spine fractures after reverse total shoulder arthroplasty (RTSA) can be devastating complications leading to substantial functional impairments. The purpose of this study was to review factors associated with increased acromial and scapular spine strain after RTSA from a biomechanical standpoint.

Methods

A systematic review of the literature was conducted based on PRISMA guidelines. PubMed, Embase, OVID Medline, and CENTRAL databases were searched and strict inclusion and exclusion criteria were applied. Each article was assessed using the modified Downs and Black checklist to appraise the quality of included studies. Study selection, extraction of data, and assessment of methodological quality were carried out independently by two of the authors. Only biomechanical studies were considered.

Results

Six biomechanical studies evaluated factors associated with increased acromial and scapular spine strain and stress. Significant increases in acromial and scapular spine strain were found with increasing lateralization of the glenosphere in four of the included studies. In two studies, glenosphere inferiorization consistently reduced acromial strain. The results concerning humeral lateralization were variable between four studies. Humeral component neck-shaft angle had no significant effect on acromial strain as analysed in one study. One study showed that scapular spine strain was significantly increased with a more posteriorly oriented acromion (55° vs. 43°; p < 0.001). Another study showed that the transection of the coracoacromial ligament increased scapular spine strain in all abduction angles (p < 0.05).

Conclusions

Glenoid lateralization was consistently associated with increased acromial and scapular spine strain, whereas inferiorization of the glenosphere reduced strain in the biomechanical studies analysed in this systematic review. Humeral-sided lateralization may increase or decrease acromial or scapular spine strain. Independent of different design parameters, the transection of the coracoacromial ligament resulted in significantly increased strains and scapular spine strains were also increased when the acromion was more posteriorly oriented. The results found in this systematic review of biomechanical in-silico and in-vitro studies may help in the surgical planning of RTSA to mitigate complications associated with acromion and scapular spine fracture.

SUBMITTER: Paszicsnyek A

PROVIDER: S-EPMC8778957 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundAcromion stress fractures (ASF) or scapular spine fractures (SSF) following reverse total shoulder arthroplasty (RTSA) are common complications with impaired clinical outcome. The underlying biomechanical factors remain unclear. The aim of this study was to evaluate basic demographic and radiographic parameters predicting occurrence of different types of ASF/SSF in a large single-center study cohort.MethodsA total of 860 RTSA (805 patients) with available minimum follow-up of 2 years were implanted between 2005 and 2018 at a tertiary academic center. All RTSA with subsequent ASF/SSF (n = 45 in 43 shoulders [42 patients, 5%]) were identified and classified as Levy I to III. Predictive demographic, surgical, and radiographic factors were evaluated for each subtype and compared to the control group (817 RTSA, 763 patients). The radiographic analysis included critical shoulder angle, lateralization shoulder angle (LSA), distalization shoulder angle (DSA), acromio-humeral distance (ACHD), acromial thickness, deltoid tuberosity index, deltoid length, and center of rotation.ResultsOf the 45 ASF/SSF in 42 patients, 8 were classified as Levy I, 21 as Levy II, and 16 as Levy III. Demographic analysis revealed indication as risk factor for Levy I fractures, higher American Society of Anesthesiologists score as risk for Levy type II fractures and higher age as risk factor for Levy type III fractures. None of the measured radiographic parameters were predictive for occurrence of Levy type I and Levy type II ASF. However, analysis of Levy III SSF revealed a higher postoperative LSA (89° ± 10° vs. 83° ± 9°, P = .015), a lower postoperative DSA (45° ± 8° vs. 53° ± 12°, P = .002), less distalization (ACHD of 33 ± 8 mm vs. 38 ± 10 mm, P = .049), and a more medial center of rotation preoperatively (COR-LA 16 ± 8 mm vs. 12 ± 7 mm, P = .048) as predictive radiographic factors.ConclusionThe present analysis showed a significant association of higher postoperative LSA, lower DSA, a lower ACHD, and higher age as predictive factor only for Levy type III fractures. Some of these factors can be surgically influenced and this knowledge can be of value for preoperative planning and surgical execution to avoid these complications.

Project description:PurposeTo compare outcomes of reverse total shoulder arthroplasty (RTSA) in patients with prior arthroscopic acromioplasty versus a control group of patients with no history of acromioplasty.MethodsWe performed a retrospective matched-cohort study of patients from a single institution who underwent RTSA with a history of acromioplasty from 2009 to 2017 with a minimum 2-year follow-up period. Patients' clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons shoulder score and Simple Shoulder Test, visual analog scale, and Single Assessment Numeric Evaluation surveys. Postoperative radiographs and patient charts were reviewed to determine whether patients sustained a postoperative acromial fracture. Charts were reviewed to determine range of motion and postoperative complications. Patients were matched on a 1:1 basis to a cohort of patients who underwent RTSA without a history of acromioplasty, and comparisons were performed using t and χ2 tests.ResultsForty-five patients who underwent RTSA with a history of acromioplasty met the inclusion criteria and completed the outcome surveys. There were no significant differences between cases and controls in post-RTSA American Shoulder and Elbow Surgeons, visual analog scale, Simple Shoulder Test, or Single Assessment Numeric Evaluation outcome scores. There was no difference in the postoperative acromial fracture rate between cases and controls (P = .577). Overall, more complications occurred in the study group (n = 6, 13.3%) compared with the control group (n = 4, 8.9%); however, this difference was not statistically significant (P = .737).ConclusionsAfter RTSA, patients who have undergone a prior acromioplasty have similar functional outcomes without a significant difference in the rate of postoperative complications compared with patients with no history of acromioplasty. Furthermore, previous acromioplasty does not increase the risk of acromial fracture after RTSA.Level of evidenceLevel III, retrospective comparative study.

Project description:BackgroundThe implantation rates of reverse total shoulder arthroplasties (RTSAs) are increasing worldwide, resulting in higher absolute numbers of the associated complications and revision surgeries. This requires the discussion of salvage therapies for failed RTSAs without revision to a new RTSA. Revision to hemiarthroplasty may offer a valid fallback option in certain cases. This study aimed to analyze the incidence, indications, and clinical outcomes, especially the reduction in pain levels compared to a matched control group.MethodsOur prospectively enrolled patient cohort of RTSA implantations at a tertiary referral center between January 2005 and December 2018 was retrospectively queried for revision to a hemiarthroplasty. For clinical outcome evaluation, a minimum follow-up duration of 2 years after revision to hemiarthroplasty was required. Clinical outcome measures were compared to two matching groups, one with RTSA preserving revision and one without any reintervention. The outcome measures were the absolute and relative Constant-Murley score (aCS and rCS), Subjective Shoulder Value (SSV), range of motion, and pain.ResultsA total of 21 out of 1237 RTSAs (1.7%) underwent salvage revision to hemiarthroplasty at a mean time of 20 ± 21 months (range, 1-75 months). Of those, 12 were available for a minimum follow-up of 2 years after revision to a hemiarthroplasty. The main indications were glenoid loosening (8/12), scapular spine fracture (2/12), and instability (2/21). Clinical outcome was analyzed at a mean follow-up period of 46 ± 26 months (24 months to 123 months) after revision to a hemiarthroplasty. The revision significantly reduced CS pain from 6 ± 4 points to 12 ± 3 points (scale 0 to 15 with 15 as optimum, P < .01). The aCS, rCS, SSV, and range of motion did not improve. Comparison with the RTSA preserving revision group and the RTSA group without reintervention showed significantly worse outcome scores for aCS (33 ± 10 vs. 55 ± 19 vs. 69 ± 12 points), rCS (41 ± 14% vs. 67 ± 20% vs. 84 ± 13%), SSV (35 ± 19% vs. 64 ± 20% vs. 81 ± 15%), flexion (53 ± 27° vs. 64 ± 20° vs. 128 ± 24°), and abduction (50 ± 23° vs. 109 ± 42° vs. 142 ± 24°). Pain was similar in all groups at the last follow-up visit.ConclusionIn a few cases, RTSA retention or revision to another RTSA is impossible. For those patients, conversion to hemiarthroplasty is a valid fallback option to reduce the patient's pain levels and provide low-level function.