Enriched mesoporous bioactive glass scaffolds as bone substitutes in critical diaphyseal bone defects in rabbits.

In the field of orthopedic surgery, there is an increasing need for the development of bone replacement materials for the treatment of bone defects. One of the main focuses of biomaterials engineering are advanced bioceramics like mesoporous bioactive glasses (MBG´s). The present study compared the new bone formation after 12 weeks of implantation of MBG scaffolds with composition 82,5SiO2-10CaO-5P2O5-x 2.5SrO alone (MBGA), enriched with osteostatin, an osteoinductive peptide, (MBGO) or enriched with bone marrow aspirate (MBGB) in a long bone critical defect in radius bone of adult New Zealand rabbits. New bone formation from the MBG scaffold groups was compared to the gold standard defect filled with iliac crest autograft and to the unfilled defect. Radiographic follow-up was performed at 2, 6, and 12 weeks, and microCT and histologic examination were performed at 12 weeks. X-Ray study showed the highest bone formation scores in the group with the defect filled with autograft, followed by the MBGB group, in addition, the microCT study showed that bone within defect scores (BV/TV) were higher in the MBGO group. This difference could be explained by the higher density of newly formed bone in the osteostatin enriched MBG scaffold group. Therefore, MBG scaffold alone and enriched with osteostatin or bone marrow aspirate increase bone formation compared to defect unfilled, being higher in the osteostatin group. The present results showed the potential to treat critical bone defects by combining MBGs with osteogenic peptides such as osteostatin, with good prospects for translation into clinical practice. STATEMENT OF SIGNIFICANCE: Treatment of bone defects without the capacity for self-repair is a global problem in the field of Orthopedic Surgery, as evidenced by the fact that in the U.S alone it affects approximately 100,000 patients per year. The gold standard of treatment in these cases is the autograft, but its use has limitations both in the amount of graft to be obtained and in the morbidity produced in the donor site. In the field of materials engineering, there is a growing interest in the development of a bone substitute equivalent. Mesoporous bioactive glass (MBG´s) scaffolds with three-dimensional architecture have shown great potential for use as a bone substitutes. The osteostatin-enriched Sr-MBG used in this long bone defect in rabbit radius bone in vivo study showed an increase in bone formation close to autograft, which makes us think that it may be an option to consider as bone substitute.

Osteogenic Potential of a Biomaterial Enriched with Osteostatin and Mesenchymal Stem Cells in Osteoporotic Rabbits.

Mesoporous bioactive glasses (MBGs) of the SiO2-CaO-P2O5 system are biocompatible materials with a quick and effective in vitro and in vivo bioactive response. MBGs can be enhanced by including therapeutically active ions in their composition, by hosting osteogenic molecules within their mesopores, or by decorating their surfaces with mesenchymal stem cells (MSCs). In previous studies, our group showed that MBGs, ZnO-enriched and loaded with the osteogenic peptide osteostatin (OST), and MSCs exhibited osteogenic features under in vitro conditions. The aim of the present study was to evaluate bone repair capability after large bone defect treatment in distal femur osteoporotic rabbits using MBGs (76%SiO2-15%CaO-5%P2O5-4%ZnO (mol-%)) before and after loading with OST and MSCs from a donor rabbit. MSCs presence and/or OST in scaffolds significantly improved bone repair capacity at 6 and 12 weeks, as confirmed by variations observed in trabecular and cortical bone parameters obtained by micro-CT as well as histological analysis results. A greater effect was observed when OST and MSCs were combined. These findings may indicate the great potential for treating critical bone defects by combining MBGs with MSCs and osteogenic peptides such as OST, with good prospects for translation to clinical practice.

Chronic Isolated Dorsal Dislocation of the Lunate. A Rare Presentation of Carpal Instability.

Isolated dorsal lunate dislocation is a rare injury. Only one case has been reported previously in which the treatment was performed in the chronic stage. In this report, we present the case of a 49-year-old handworker male who presented a dorsal dislocation of the lunate after a traffic accident. He was referred to our clinic 2.5 months later due to an initial misdiagnosis. Surgical treatment was performed and consisted of an open reduction using a nerve-sparing dorsal approach. A complete rupture of the perilunate ligaments and a marked instability of the lunate were detected. Stabilisation of the scapholunate, lunotriquetral and scaphocapitate spaces with a compression screw and Kirschner wires, respectively, was performed. The persistence of pain and functional limitation after the surgery along with an insufficient reduction of the scapholunate space on the X-ray and the development of a fistula on the ulnar edge of the carpus prompted reintervention. A hardware-free total wrist arthrodesis was preferred over other procedures, such as proximal row carpectomy, owing to the important articular damage. At the 3-month follow-up, he was clinically stable, consolidation of arthrodesis was documented and he had returned to his previous activities. Isolated dorsal dislocation of the lunate is a rare lesion. There is no consensus on the management of isolated chronic dislocations of the lunate. The frequent delay in the diagnosis compromises the final outcome of reconstructive techniques and introduces the risk of residual instability, increasing the incidence of chronic pain associated with post-traumatic osteoarthritis. In the case of chronic lesions, treatment with palliative techniques, such as proximal carpectomy or joint arthrodesis, should be considered. How to cite this article: Alonso-Tejero D, Luengo-Alonso G, Jiménez-Díaz V, et al. Chronic Isolated Dorsal Dislocation of the Lunate. A Rare Presentation of Carpal Instability. Strategies Trauma Limb Reconstr 2022;17(1):59-62.

Correlation between radiographic findings and clinical failure in monopolar radial head replacement.

INTRODUCTION: The purpose of this study is to analyze the mid-term outcomes of a modular monopolar type of radial head arthroplasty in the treatment of complex fractures associated with acute elbow joint instability. We postulated that radiographic changes are related to the development of clinical complications. MATERIALS AND METHODS: We evaluated at last follow-up 26 radial head arthroplasties in 26 consecutive patients who were followed for at least one and a half year. All patients had suffered radial head fractures (Mason III) in the context of unstable elbow injuries. Definitive treatment of the radial fracture was performed with modular and monopolar prosthesis which was inserted as a press fit. All patients were evaluated preoperatively and postoperatively. The evaluation included a clinical examination and a protocolized imaging study (standard X-Rays and CT) of the elbow. We analyzed the incidence of: heterotopic ossifications, secondary radiocapitellar joint osteoarthritis, hardware loosening, hardware disengagement, and joint infection. Diagnosis of clinical failure of the implant was defined as the time to the second surgery due to major complications related to the prosthesis, such as persistent lateral side pain or elbow stiffness and any kind of implant instability or dislocation. RESULTS: The implant-specific reoperation rate was 15% (four reoperations). The need for the second surgery was statistically associated with heterotopic ossifications, radiocapitellar osteoarthritis and cortical resorption around radial neck (p = 0.054, p = 0.033, and p = 0.019, respectively), being periprosthetic osteolysis the most likely factor related to failure, and radial pain the main symptom leading to surgical revision. CONCLUSIONS: Our study shows a positive association between radiographic findings and patient symptoms for postoperative complications after radial head arthroplasty. Failed radial head replacements may lead to reoperation mainly due to pain, and this can be distinguished from other causes of pain in elbow region based on its radial location. Radiological loosening was prevalent in this group of failed replacement.

Arthrodesis of the thumb carpometacarpal joint using a quadrangular plate: surgical technique and long-term results of 70 patients.

PURPOSE: To assess the long-term results of trapeziometacarpal arthrodesis using a quadrangular plate, regarding clinical, radiological and functional outcomes, as well as development of complications. MATERIAL AND METHOD: From 2005 to 2015, 70 patients were treated at our institution for primary osteoarthrosis of thumb carpometacarpal joint performing a trapeziometacarpal arthrodesis. A total of 85 arthrodesis were carried out using a titanium quadrangular plate (Proflyle plate, Stryker®, Kalamazoo MI, USA), without grafting in any case. Pre- and postoperative functional data were assessed at the outpatient clinics using DASH, MWS and VAS. All patients were asked for their ability to perform basic daily activities before and after surgery. All patients were also asked about satisfaction and their return to their jobs after surgery. Pre- and postoperative radiological data were also assessed. RESULTS: There were 59 females and 11 males with an average age of 55 years (range 44-60). In 66 cases arthrodesis was carried out in the dominant hand, in 45 cases the right thumb was involved, and in 40 the left thumb was involved; in 15 cases arthrodesis was carried out bilaterally. Preoperative average DASH score was 64 (range 50-85), postoperative average score was 25 (range 5-61). Regarding MWS, 51 patients obtained excellent results, 15 patients obtained good results and 4 patients referred poor results. The preoperative average score of VAS was 6 (range 5-10), which decrease to an average of 2 (range 0-3) after surgery; all those differences were statistically significant. All patients reported a mild loss of motion; however, all of them reported improvement to carry out daily activities. There were four cases of nonunion because of failure of fixation and two cases with dysesthetic scar. There was no development of osteoarthritis in adjacent joints. The average follow-up was 60 months. CONCLUSIONS: The use of quadrangular plates for arthrodesis of the trapeziometacarpal joint is a safety and reproducible technique with a low rate of complications. Arthrodesis decreases pain and improves function in patients with primary osteoarthritis of the thumb carpometacarpal joint; in spite of a mild loss of motion, patients are satisfied with this procedure.

Analysis of complications after a floating elbow injury.

BACKGROUND: The aim of the present study is to analyse complications after a floating elbow injury, attempting to establish which of them act as a poor prognosis factor regarding clinical and functional results. MATERIALS AND METHODS: Twenty-three patients who suffered a floating elbow injury, treated at our institution from 2004 to 2013, were retrospectively reviewed. Patients were divided into four groups depending on the type of injury. An analysis of demographic data, associated injuries, treatment options and complications was carried out. Clinical evaluation was made by a conventional goniometer, testing flexo-extension and prono-supination ranges. For functional evaluation, the Mayo Elbow Performance Score was employed. Association between radioulnar synostosis, articular surface disruption, nerve injury and clinical and functional results was analysed. RESULTS: Patients with radioulnar synostosis had worse results in functional evaluation than patients without it (56.6 vs. 75); this difference was statistically significant (p = 0.05). Regarding intra-articular extension, we found statistical association with worse results in functional evaluation (p = 0.018); however, nerve palsy does not seem to influence functional results. CONCLUSIONS: Radioulnar synostosis and intra-articular extension of the injury are poor prognosis factor in floating elbow.

Comparison between external fixators and fixed-angle volar-locking plates in the treatment of distal radius fractures.

Distal radius fractures are a common disorder in industrialized nations associated with osteoporosis, with a reported incidence of two fractures per thousand patients per year. We performed a retrospective study comparing two sets of 40 patients, with fracture of the distal radius treated with Penning external fixator, compared to 40 patients treated with fixed-angle volar-locking plate (Plate Depuy ® DVR), with the objective of finding differences between both treatment methods in anatomical values, functional outcomes and complication rates. All fractures were classified according to the AO classification. Postero-anterior and lateral radiographs of the wrist were taken after fracture, after surgery and at 6 months after surgery. We also assessed functional outcome. Minimum follow up was of 10 months. We compared complications between both groups. In the group of patients treated with fixed-angle volar-locked plate, radiological results are found to be closer to the anatomical references. Final outcomes revealed similar functional scores between both groups. The complications rate was statistically higher in the group of patients who underwent external fixation. In the fixed-angle volar-locked plate group, most of complications were related to patient discomfort due to the volar-locking plate.