Restoration in Vertebral Compression Fractures (VCF): Effectiveness Evaluation Based on 3D Technology.

There are few studies about anatomical reduction of the fractured vertebral body before stabilization for treatment of vertebral compression fracture (VCF). Although restoration on vertebral height has been useful, the reduction of fractured endplates is limited. The vertebra is part of a joint, and vertebral endplates must be treated like other weight-bearing joint to avoid complications. The aim of this study was to evaluate the feasibility of anatomic reduction of vertebral compression fracture, in different bone conditions, fracture types, and ages (VCF). Under methodological point of view, we followed different steps: first was the placement of two expandable titanium implants just below the fracture. Later, to push the fractured endplates into a more anatomical position, the implants were expanded. Finally, with the implants perfectly positioned, PMMA cement was injected to avoid any loss of correction. To evaluate the effectiveness of this procedure in anatomical fracture reduction, a method based on 3D CT reconstructions was developed. In this paper, we have developed the procedure in three case studies. In all of them, we were able to demonstrate the efficacy of this procedure to reduce the VCF. The percentage of correction of the kyphotic angle varied range between 49% and 62% with respect to the value after the fracture preoperative value. This was accompanied by a reduction of the pain level on the VAS scale around 50%. In conclusion, this novel approach to the vertebral fracture treatment (VCF) associated with 3D assessment have demonstrated the possibility of reducing the vertebral kyphosis angle and the vertebral endplate fractures. However, given the few cases presented, more studies are necessaries to confirm these results.

MIPO helical pre-contoured plates in diaphyseal humeral fractures with proximal extension. Surgical technique and results.

INTRODUCTION: The aim of this study was to determine the feasibility of applying the MIPO technique with a helical-shaped plate in the treatment of humeral shaft fractures with proximal extension. PATIENTS AND METHODS: We present an observational prospective study of patients with a humeral shaft fracture involving the proximal humerus fixed with a long proximal humerus polyaxial locking plate with an anterior curvature and helical shape (ALPS® Zimmerbiomet, Warsaw, Indianapolis, USA), using a MIPO technique. Between January 2017 and July 2020, 15 patients were treated at our institution. Proximally a 4-5 cm anterolateral transdeltoid approach was made. And distally, a 5-7 cm incision was made 4 cm proximal to the elbow crease. At each follow-up, radiographs were taken to evaluate fracture healing. Funtional scales were applied to evaluate clinical results. RESULTS: Ten women and five men were included, with a mean age of 62 yo (range 26-86). All but one fracture healed uneventfully. The mean time to union was 28 weeks (range 12-48 weeks). Two out of 15 patients presented complications (an atrophic nonunion and a peri­implant distal fracture). None of the patients had a nerve palsy prior neither after the surgery. No other complications, including infection, were registered during follow-up. Shoulder range of motion showed the following means: abduction of 147° (range 50°-180°), anterior flexion of 144° (range 80°-180°), external rotation of 77,5 ° (range 70°-80°) and internal rotation of 54.5° (range 45°-60°). All patients recovered their pre-fracture elbow range of motion. All patients presented less than 10° of angular deviation in varus/valgus or ante/recurvatum after the surgical procedure. At the end of the follow-up, all final functional scores were "good" or "excellent": mean Constant-Murley score was 72 ± 13 (range 38-91), ASES score was 73 ± 12 (range 41-88), UCLA shoulder scale was 30 ± 3,5 (range 10-35), and Q-DASH score was 16.5 ± 0,11 (range 4-57). CONCLUSION: When applied correctly, the treatment of diaphyseal humeral fractures involving the proximal humerus using a polyaxial locking helical plate with a MIPO technique is a reliable treatment method. It has high union rates with low complications.

Elastin-Like Recombinamer Hydrogels for Improved Skeletal Muscle Healing Through Modulation of Macrophage Polarization.

Large skeletal muscle injuries, such as a volumetric muscle loss (VML), often result in an incomplete regeneration due to the formation of a non-contractile fibrotic scar tissue. This is, in part, due to the outbreak of an inflammatory response, which is not resolved over time, meaning that type-1 macrophages (M1, pro-inflammatory) involved in the initial stages of the process are not replaced by pro-regenerative type-2 macrophages (M2). Therefore, biomaterials that promote the shift from M1 to M2 are needed to achieve optimal regeneration in VML injuries. In this work, we used elastin-like recombinamers (ELRs) as biomaterials for the formation of non- (physical) and covalently (chemical) crosslinked bioactive and biodegradable hydrogels to fill the VML created in the tibialis anterior (TA) muscles of rats. These hydrogels promoted a higher infiltration of M2 within the site of injury in comparison to the non-treated control after 2 weeks (p<0.0001), indicating that the inflammatory response resolves faster in the presence of both types of ELR-based hydrogels. Moreover, there were not significant differences in the amount of collagen deposition between the samples treated with the chemical ELR hydrogel at 2 and 5 weeks, and this same result was found upon comparison of these samples with healthy tissue after 5 weeks, which implies that this treatment prevents fibrosis. The macrophage modulation also translated into the formation of myofibers that were morphologically more similar to those present in healthy muscle. Altogether, these results highlight that ELR hydrogels provide a friendly niche for infiltrating cells that biodegrades over time, leaving space to new muscle tissue. In addition, they orchestrate the shift of macrophage population toward M2, which resulted in the prevention of fibrosis in the case of the chemical hydrogel treatment and in a more healthy-like myofiber phenotype for both types of hydrogels. Further studies should focus in the assessment of the regeneration of skeletal muscle in larger animal models, where a more critical defect can be created and additional methods can be used to evaluate the functional recovery of skeletal muscle.