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.

In vivo behavior in rabbit radius bone defect of scaffolds based on nanocarbonate hydroxyapatite.

Bone defects treatment may require the use of biomaterials that behave as a support and promote bone regeneration. Limitations associated with the use of autografts and allografts make it necessary to design new synthetic bone substitutes. Some of the most promising biomaterials currently under investigation are based on nanocarbonate hydroxyapatite (nCHA). In this study, we studied the bone-inducing capacity of nCHA-based scaffolds alone (SAG) and enriched with osteostatin (SAGO) or with bone marrow aspirate(SAGB) after implantation for 12 weeks in a 15-mm long critical defect performed in the radius of New Zealand rabbits. Bone formation obtained was compared with a group with the unfilled defect (CE), as control group, and other with the defect filed with iliac crest autograft (GS), as gold standard. X-ray follow-up was performed at 2, 4, 6 and 12 weeks and µCT and histological studies at 12 weeks. The radiological results showed a greater increment in bone formation in the GS group (75%-100%), followed by the SAG and SAGB groups (50%-75%). µCT results showed an increase of bone volume/tissue volume values in GS group followed by SAG and SAGB groups (0.53, 0.40, and 0.31 respectively) compared with CE group (0.26). Histological results showed limited resorption of the nCHA scaffolds and partial osseointegration in the SAG and SAGB groups. However, in the SAGO group, the presence of connective tissue encapsulating the scaffold was detected. In SAG, SAGB, and increase of bone formation were observed compared with CE group, but less than the GS group. Thus, the investigated materials represent a significant advance in the design of synthetic materials for bone grafting, but further studies are needed to bring their in vivo behavior closer to autograft, the gold standard.

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.

Acute complex instability of the elbow treated with internal joint stabilizer IJS-E System. / Tratamiento de la inestabilidad aguda compleja de codo con fijador interno IJS-E System.

INTRODUCTION: Treatment of acute complex fracture-dislocation of the elbow has been associated with a high rate of complications. Internal Joint Stabilizer of the Elbow (IJSE) device appears as a valid option to optimize and improve our results. MATERIAL AND METHODS: We present a retrospective case series of five patients treated at our institution with IJS-E System (Skeletal DynamicsR) from February 2019 to 2020. Our inclusion criteria was: patients over 18 years old surgically treated with IJS-E due to persistent elbow instability despite of a suitable osteoligamentous surgical repair. RESULTS: We obtained a total of five patients (4 males and 1 female) with an average age of 37.4 years old (24-71). The Injury pattern was posterolateral instability, TTIE in all cases. The mean final postoperative MEP score was 94 points (85-100) and the postoperative DASH score was 11.78 points (4.2-20.6) with an average follow-up of 9.8 months (6-12). We described a final arc of motion of 134° with a range of flexionbetween 120° and 140° and a mean lack of extension of 12° (5°-20°), with a complete arc of pronosupination. As complications we found one case of heterotopic ossfication and one case of elbow stiffnes. However, no complications device-related or articular incongruence were reported during follow-up. CONCLUSIONS: The IJS-E device appears as an effective alternative instead of external fixation. Nevertheless, a high rate of reoperation up to 100% is associated with IJS-E. A larger series, longer follow-up and prospective studies are needed to define properly his role in the surgical treatment of acute elbow instability.

The anconeus muscle revisited: double innervation pattern and its clinical implications.

PURPOSE: The aim of the present study is to describe in detail the morphology and innervation pattern of the anconeus muscle, bearing in mind clinical implications such as iatrogenic injuries during surgical elbow approaches. METHODS: A cadaveric study was performed; 56 elbows from 28 formalin-fixed cadavers belonging to the Anatomy Department of Universidad Complutense of Madrid were dissected. The triceps-anconeus nerve was located and dissected. A second innervation to the anconeus muscle from a branch of the posterior interosseous nerve (PIN) was occasionally detected. Taking the lateral epicondyle as a landmark, the entry points of both nerves in the muscle were referenced, the triceps-anconeus nerve was referenced at 0°, 30°, 45°, 70° and 90° of elbow flexion, and the PIN branch at 0°. RESULTS: Anconeus muscle was present in all specimens. The triceps-anconeus nerve was present in all of the dissected elbows. A branch from PIN to the anconeus muscle was present in 38 of the 54 elbows (70.4%). There were statistically significant differences in all measurements regarding the specimens' gender, being higher for men. CONCLUSIONS: There is evidence of a high frequency of a double innervation pattern for the anconeus muscle: the main branch of triceps-anconeus muscle depending on the radial nerve, which is liable to being damaged during posterior elbow approaches, and a secondary branch depending on the PIN. There are very few references to this finding in Anatomical literature and none with such a large sample size.

Arthroscopic Subtalar Arthrodesis: Does the Type of Fixation Modify Outcomes?

The goal of the present study was to analyze a modified American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale score, time to union, and the incidence of fusion after isolated arthroscopic posterior subtalar arthrodesis using either 1 or 2 screws of different diameters. We reviewed a consecutive series of 65 patients, mean age 50.0 ± 15.6 years, including 38 males (58.5%) and 27 females (41.5%), who had undergone arthrodesis from May 2004 to February 2011. The mean follow-up duration was 57.5 (range 24 to 105) months. The patients were divided into 3 groups according to the fixation method used: group 1 (n = 12; 18.5%) underwent fixation with one 6.5-mm screw; group 2 (n = 40; 61.5%) with one 7.3-mm screw; and group 3 (n = 13; 20%) with two 7.3-mm screws. An overall statistically significant (p <.0001) improvement was seen in the modified AOFAS scale score for all 3 fixation groups; however, the difference was not statistically significant (p = .79) among the fixation groups. Fusion was achieved in 62 patients (95.4%) after a mean of 12.1 (range 9 to 16) weeks. The difference in the time to union was not statistically significant (p = .781) among the fixation groups. Nine patients (13.8%) experienced complications, and nonunion was significantly (p = .005) more prevalent in the single 6.5-mm screw group. In conclusion, all 3 screw configurations led to improved modified AOFAS scale scores, although nonunion was more common among patients fixed with a single 6.5-mm screw.

Predicting syndesmotic injuries in ankle fractures: a new system based on the medial malleolar focus.

The early establishment of the diagnosis of a syndesmotic injury is essential for treatment selection. However, such injuries may not be apparent radiographically. Previous studies have attempted to describe correlations between medial malleolar fracture geometry and syndesmotic disruption. The main objective of this study was to create predictive models for assessing syndesmotic injuries based on an originally described angle, i.e., the medial crural-focal angle (MCFA). This study included 138 ankle fractures involving the medial malleolus. Any measure from the plain radiograph that could potentially lead to the suspicion of a syndesmotic disruption was recorded, and the newly described MCFA (formed by the main line of the medial malleolus fracture and a line perpendicular to the bearing surface of the tibial plafond) was also recorded. The inter- and intraobserver reliabilities were obtained using Krippendorff's alpha coefficients. To examine the predictive abilities of every parameter, several statistical methods were applied including logistic regression, an ad hoc clinical rule, and discriminant analysis. After variable selection, we obtained the best possible logistic model. The variables that were found to be statistically significant were the MCFA, the tibiofibular clear space (TFCS) and the type of injury in the Lauge-Hansen (L-H) classification. This model was tested by cross validation, which revealed a mean percentage of correctly classified patients of 88%. A simpler and more intuitive alternative model was sought that was based solely on the influences of the MCFA and the TFCS. Our study revealed that an absence of syndesmotic disruptions when the MCFA was under 60°, and there were no uninjured patients with tibiofibular clear space values over 6mm. Cross-validation revealed that the mean percentage of patients who were correctly classified with this model was 86%. The application of discriminant analysis to this combination of variables resulted in a function was able to correctly classify a mean of 84% of patients. In conclusion, three models that can predict syndesmotic injury using parameters from preoperative plain radiographs were obtained and validated. The MCFA measurement was in these models and found to be a reliable technique.

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.

Subtalar arthroscopic arthrodesis: Technique and outcomes.

PURPOSE: The goal of this study was to describe the surgical technique and our results with arthroscopic posterior subtalar arthrodesis. MATERIAL AND METHODS: Retrospective case series of 65 patients (38 men and 27 women) averaging 50 years of age (range 21-72 years) undergoing posterior arthroscopic subtalar arthrodesis using one or two percutaneous 6.5-7.3mm screws between May 2004 and February 2011, with a mean follow-up of 57.5 months (range 24-105 months). RESULTS: We achieved a 95.4% union rate after an average of 12.1 weeks (range 9 to 16 weeks). 12.3% of patients suffered complications, including superficial infection, nonunion and need for hardware removal. The AOFAS score improved from 51.5 points (19-61 points) preoperatively to 81.9 points (60-94 points) in the postoperative period. CONCLUSIONS: We describe the surgical technique for arthroscopic subtalar arthrodesis, which as proven to be a safe and reliable technique in our experience, with consistent improvements in AOFAS scores.

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.

Treatment of a Complex Distal Triceps Tendon Rupture With a New Technique: A Case Report.

INTRODUCTION: The distal triceps tendon rupture is an uncommon injury. The acute treatment is well-defined, but when a delayed diagnosis is made or when a tendon retraction is present the alternatives or reconstruction are limited and sometimes complex. CASE PRESENTATION: In this case, we report on a 28-year-old man who presented with a chronic disruption of the distal triceps tendon with a gap of approximately 15 cm. The patient was diagnosed in another center with an inveterate breakage of the distal triceps tendon and was initially treated with an Achilles allograft that was complicated by a wound infection and required more than ten surgeries. Nearly 22 months after the initial trauma, and 12 months after the first surgery, we performed a reconstruction with an Achilles tendon allograft using the new technique of distal attachment. At the 12-month follow-up the patient presented a joint balance from -5º to 110º and presented with no pain. CONCLUSIONS: The use of an Achilles tendon allograft provides excellent results in complex distal triceps tendon ruptures. We report the use of a new technique to anchor a distal Achilles allograft.

Results of Arthroscopic Subtalar Arthrodesis for Adult-Acquired Flatfoot Deformity vs Posttraumatic Arthritis.

BACKGROUND: The goal of this study was to compare results with arthroscopic posterior subtalar arthrodesis between patients treated for adult-acquired flatfoot deformity (AAFD) due to posterior tibial tendon dysfunction and patients with posttraumatic subtalar arthritis. METHODS: Retrospective case series of 61 consecutive patients (group 1: posttraumatic arthritis, n = 37; group 2: AAFD, n = 24) averaging 49 years of age (range, 21-72 years) undergoing posterior arthroscopic subtalar arthrodesis via 1 or 2 percutaneous 6.5- to 7.3-mm screws, with a mean follow-up of 57.5 months (range, 24-105 months). Fusion was defined as the appearance of bony trabeculae across the subtalar joint on standard x-rays, along with clinical signs of union. RESULTS: Patients with posttraumatic arthritis (group 1) were more predominantly male and younger than patients treated for AAFD (group 2). Overall, we achieved a 95.1% radiologic union rate after an average of 11.7 weeks. Complications appeared in 14.8% of patients. Union rate and complications did not differ significantly between groups. American Orthopaedic Foot & Ankle Society (AOFAS) scores improved significantly for both patient groups, although patients with AAFD showed significantly larger improvement and higher postoperative AOFAS scores, even after adjusting for age and sex (mean improvement in AOFAS scores: 27.0 ± 9.1 points for the posttraumatic arthritis group vs 34.9 ± 7.4 points for the AAFD group; P < .001). CONCLUSIONS: Arthroscopic subtalar arthrodesis was a safe and reliable technique, with consistent improvement in AOFAS scores throughout different patient subgroups, as well as comparable time to union and complication rates. Improvements were larger for patients treated for AAFD, even after adjusting for age and sex. LEVEL OF EVIDENCE: Level III, retrospective case series.