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.

Synthesis and Photochromism of Novel Pyridyl-Substituted Naphthopyrans.

Multitarget synthetic strategies to access novel photochromic 3H-naphtho[2,1-b]pyrans decorated with pyridyl units are described. The new pyridyl-substituted 3H-naphtho[2,1-b]pyrans display good photochromic properties with reversible generation of photomerocyanines, which exhibit mainly orange/red hues. Photochromic parameters including photocolorability and persistence of color vary tremendously on structural modification of the naphthopyran core.

Treatment of post-traumatic humeral diaphyseal nonunion with bone loss.

Four patients with post-traumatic nonunion and shortening of the humeral diaphysis were treated with a hybrid advanced Ilizarov technique. The mean age of the patients was 32 years, and the mean total amount of humeral shortening was 6.63 cm. Three nonunions were atrophic and infected, and one was hypertrophic. All patients obtained union of the humeral fracture with resolution of infection at a mean external fixation time of 8 months. Restoration of normal humeral length was achieved in two patients, with a third having a residual discrepancy of 1 cm. The final patient, who had an infected nonunion with 11 cm of total humeral shortening, had a residual limb length discrepancy of 3 cm. All had improvement in shoulder and elbow motion after treatment. Superficial pin tract infections were seen in all patients, but all responded to pin-site care and oral antibiotics. Two patients had three refractures after removal of the fixator, two of which were treated by a second application of an Ilizarov frame and one by a cast. All patients had reduced pain and improved function at completion of the treatment. The Ilizarov method, though not a panacea for all humeral nonunions with extensive bone loss, does offer a viable salvage procedure in this unusual and often complex clinical problem.

Treatment of the late sequelae of septic arthritis of the hip.

Numerous salvage procedures have been proposed for the treatment of late sequelae of septic arthritis of the hip. Despite this, there are no reports in the literature discussing treatment with simultaneous hip reconstruction and femoral lengthening using the hybrid advanced Ilizarov method. The authors reviewed their experience with this technique, and present 15 patients treated between 1982 and 1997. The average age of the patients was 21.1 years and the average limb length discrepancy was 6.5 cm. All the hips were classified according to the classification of Choi et al. The time the external fixator was worn was 225.5 days and the average followup was 108 months. The results were classified based on pain relief, residual deformity, range of motion, Trendelenburg sign, and limb length discrepancy. Ten patients had a good or excellent result, three patients had a fair result, and only two patients had a poor result. Major complications included a common peroneal nerve palsy in one patient, loss of angulation of the proximal femoral osteotomy in two patients, and a mild knee subluxation in three patients all of whom responded to treatment. At the latest followup, 13 patients were satisfied with the treatment, all had returned to their previous occupations, and no patient had a total hip arthroplasty.