A new all-suture tension band tape fixation technique for simple olecranon fractures versus conventional tension band wire fixation: a comparative biomechanics study.

HYPOTHESIS: Simple transverse or short oblique olecranon fractures without articular comminution are classified as Mayo type IIA fractures and are typically treated with a tension band wire construct. Because of the high reoperation rates, frequently because of prominent hardware, all-suture tension band constructs have been introduced. It was the purpose to compare the biomechanical performance of conventional tension band wire fixation with a new all-suture tension band tape fixation for simple olecranon fractures. METHODS: Mayo type IIA olecranon fractures were created in 20 cadaveric elbows from 10 donors. One elbow of each donor was randomly assigned to the tension band wire technique (group TBW) or tension band tape (Arthrex, 1.3-mm SutureTape) technique (group TBT). Both groups were cyclically loaded with 500 N over 500 cycles, after which a uniaxial displacement was performed to evaluate load to failure. Data were analyzed for gap formation after cyclic loading, construct stiffness, and ultimate load to failure, where failure was defined as fracture gap formation greater than 4.0 mm. RESULTS: There was no significant difference in gap formation after 500 cycles between the TBW (1.8 mm ± 1.3 mm) and the TBT (1.9 mm ± 1.1 mm) groups (P = .854). The TBT showed a tendency toward greater construct stiffness compared with the TBW construct (mean difference: 142 N/mm; P = .053). Ultimate load to failure was not significantly different comparing both groups (TBW: 1138 N ± 286 N vs. TBT: 1126 N ± 272 N; P = .928). In both groups, all repairs failed because of >4.0-mm gap formation at the fracture site and none because of tension band construct breakage. CONCLUSIONS: Our study shows that the TBT technique produces equivalent or superior biomechanical performance to the TBW for simple olecranon fractures. The TBT approach reduces the risk of hardware prominence and as a result mitigates against the need for hardware removal. The TBT technique offers a clinically viable alternative to TBW.

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

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.

Prosthesis Designs and Tuberosity Fixation Techniques in Reverse Total Shoulder Arthroplasty: Influence on Tuberosity Healing in Proximal Humerus Fractures.

Reverse total shoulder arthroplasty (RTSA) is increasingly used for the treatment of complex proximal humerus fractures and fracture sequelae. In 2021, half a dozen models of fracture stems are commercially available, reflecting its growing utility for fracture management. Prosthesis designs, bone grafting and tuberosity fixation techniques have evolved to allow better and more reliable fixation of tuberosities and bony ingrowth. Patients with anatomical tuberosity healing not only have an increased range of active anterior elevation and external rotation, but also experience fewer complications and longer prosthesis survival. This review provides an overview of recent evidence on basic and fracture-specific RTSA design features as well as tuberosity fixation techniques that can influence tuberosity healing.

Retrospective cohort study evaluating the efficacy and safety of an orthopaedic consultant-led virtual fracture clinic in an Australian level 1 trauma centre.

BACKGROUND: In Australian health care, the consistent rise in demand for orthopaedic outpatient clinic services is creating marked challenges in the provision of quality care. This study investigates the efficacy and safety of a virtual fracture clinic (VFC) as an alternative model of care for the management of acute injuries and musculoskeletal conditions in the Australian public hospital setting. METHODS: A retrospective cohort study of consecutive emergency department (ED) referrals to the Department of Orthopaedic Surgery was conducted comparing outcomes prior to (November 2015-February 2017) and after (March 2017-June 2018) implementation of a VFC. The primary outcome measures assessed were the proportion of referrals virtually discharged and unplanned 30-day ED re-attendance rates. RESULTS: A total of 737 (36.4%) referrals managed by the VFC were discharged without requiring orthopaedic outpatient clinic attendance. The rate of unplanned ED re-attendances was 5.2% post-VFC implementation compared to 6.5% at baseline (P = 0.01). VFC implementation was also associated with reductions in the average number of orthopaedic outpatient clinic attendances per referral (1.1 versus 1.7, P < 0.01) and the number of referrals lost to follow-up (7.2% versus 14.7%, P < 0.01). In addition, patient wait times for first contact by the orthopaedic team were significantly reduced from a median of 7 (IQR 5, 9) days to 2 (IQR 1, 3) days post-intervention (P < 0.01). No complications or adverse events were reported. CONCLUSION: This study demonstrates that a VFC is applicable to the Australian healthcare system, and can lead to effective and safe provision of orthopaedic outpatient care.

Axillary Artery Injury Associated with Proximal Humeral Fractures: Review of Long-Term Vascular, Orthopedic, and Neurologic Outcomes.

BACKGROUND: Fracture and dislocation of the proximal humerus is common. It is associated with a number of vascular, neurologic, and orthopedic complications; these include brachial plexopathy and avascular necrosis (AVN) of the humeral head. These complications are rare but can potentially cause severe disability to patients; however, they remain poorly described in the literature. To describe vascular, orthopedic, and neurologic outcomes after axillary artery repair, in patients with proximal humeral fractures or dislocations. METHODS: We conducted a retrospective review of patients admitted to 2 tertiary trauma centers in Victoria, Australia, with fracture or dislocation of the proximal humerus and associated axillary artery injury. Patients were selected according to guidelines for trauma call or alert and the presence of high-risk mechanism of injury. Data on vascular, orthopedic, and neurologic complications were collected. RESULTS: Twenty-one patients were identified. Injury to the first part of the axillary artery was noted in 11 patients (52%). Brachial plexus exploration was performed in 17 patients (81%). Four patients (19%) underwent nerve repair. Long-term neurologic recovery was universally poor. Major orthopedic complications included AVN of the humeral head, delayed union, and the need for prosthesis or arthrodesis. Eleven patients (52%) received upper limb fasciotomy. Five patients (24%) underwent delayed secondary upper limb amputation. CONCLUSIONS: There was an unusually high rate of injuries to the first part of the axillary artery. Close clinical observation is recommended for such patients. AVN of the humeral head and brachial plexopathy remain significant and debilitating complications.

What is the Best Clinical Test for Assessment of the Teres Minor in Massive Rotator Cuff Tears?

BACKGROUND: Few studies define the clinical signs to evaluate the integrity of teres minor in patients with massive rotator cuff tears. CT and MRI, with or without an arthrogram, can be limited by image quality, soft tissue density, motion artifact, and interobserver reliability. Additionally, the ill-defined junction between the infraspinatus and teres minor and the larger muscle-to-tendon ratio of the teres minor can contribute to error. Therefore, we wished to determine the validity of clinical testing for teres minor tears. QUESTION/PURPOSES: The aim of this study was to determine the accuracy of commonly used clinical signs (external rotation lag sign, drop sign, and the Patte test) for diagnosing the teres minor's integrity. METHODS: We performed a prospective evaluation of patients referred to our shoulder clinic for massive rotator cuff tears determined by CT arthrograms. The posterosuperior rotator cuff was examined clinically and correlated with CT arthrograms. We assessed interobserver reliability for CT assessment and used three different clinical tests of teres minor function (the external rotation lag sign, drop sign, and the Patte test). One hundred patients with a mean age of 68 years were available for the analysis. RESULTS: The most accurate test for teres minor dysfunction was an external rotation lag sign greater than 40°, which had a sensitivity of 100% (95% CI, 80%-100%) and a specificity of 92% (95% CI, 84%-96%). External rotation lag signs greater than 10° had a sensitivity of 100% (95% CI, 80%-100%) and a specificity of 51% (95% CI, 40%-61%). The Patte sign had a sensitivity of 93% (95% CI, 70%-99%) and a specificity of 72% (95% CI, 61%-80%). The drop sign had a sensitivity of 87% (95% CI, 62%-96%) and a specificity of 88% (95% CI, 80%-93%). An external rotation lag sign greater than 40° was more specific than an external rotation lag sign greater than 10° (p < 0.001), and a Patte sign (p < 0.001), but was not more specific than the drop sign (p < 0.47). There was poor correlation between involvement of the teres minor and loss of active external rotation. CONCLUSIONS: Clinical signs can predict anatomic patterns of teres minor dysfunction with good accuracy in patients with massive rotator cuff tears. This study showed that the most accurate test for teres minor dysfunction is an external rotation lag sign and that most patients' posterior rotator cuff tears do not lose active external rotation. Because imaging is not always accurate, examination for integrity of the teres minor is important because it may be one of the most important variables affecting the outcome of reverse shoulder arthroplasty for massive rotator cuff tears, and the functional effects of tears in this muscle on day to day activities can be significant. Additionally, teres minor integrity affects the outcomes of tendon transfers, therefore knowledge of its condition is important in planning repairs. LEVEL OF EVIDENCE: Level III, diagnostic study.