A larger radius of the medial femoral posterior condyle is a risk factor for medial meniscus posterior root tears.

BACKGROUND: Studies have shown an association between medial meniscus posterior root tears (MMPRT) and morphologic characteristics of the bone. However, the association between distal femoral bone morphology and MMPRT, particularly the medial femoral posterior condyle, is poorly understood. Our study aimed to determine the association between the morphologic characteristics of the medial posterior femoral condyle and MMPRT. METHODS: A retrospective case-control study was performed from January 2021 to January 2022. After screening based on the inclusion and exclusion criteria, two matched groups were analyzed: the MMPRT group and the isolated lateral meniscus tears group. The hip-knee-ankle angle (HKA) and Kellgren-Lawrence grade (KLG) were measured on radiographs; the medial tibial slope angle (MTSA), medial tibial plateau depth (MTPD), and radius of the medial femoral posterior condyle (RMFPC) were measured on magnetic resonance imaging (MRI) in both groups. The area under the curve (AUC) and the best cutoff value for predicting MMPRT were calculated by using receiver operating characteristic (ROC) curve analysis. RESULTS: The final analysis included a total of 174 patients (87 MMPRT patients and 87 controls). Significant differences were shown in the RMFPC (17.6 ± 1.0 vs. 16.2 ± 1.0, p < 0.01) and MTSA (6.4 ± 2.0 vs. 4.0 ± 1.3, p < 0.01), which were larger than those of the control group. The MTPD (1.8 ± 0.6 vs. 2.9 ± 0.7, p < 0.01) and HKA (175.4 ± 2.2 vs. 179.0 ± 2.7, p < 0.01) of the injury group were significantly different from the control group, and both were lower than the control group. However, between the MMPRT and control groups on the KLG (2.3 ± 0.6 vs. 2.2 ± 0.6, p = 0.209), there was no statistically significant difference. Among them, the RMFPC cutoff value was calculated to be 16.8 mm by ROC curve analysis, and the sensitivity and specificity were both 81.61%. CONCLUSIONS: This study demonstrated that larger RMFPC, MTSA, smaller MTPD, and HKA were all associated with MMPRT, and RMFPC ≥ 16.8 mm was considered as a significant risk factor for MMPRT.

Effect of the Sauvé-Kapandji method on the wrist contact surface for distal radial ulnar joint disorders.

BACKGROUND: The Sauvé-Kapandji (S-K) method is a surgical procedure performed for chronic deformities of the distal radial ulnar joint (DRUJ). Changes to the joint contact surface from pre- to postoperatively under physiological in vivo conditions have not yet been determined for this useful treatment. The aim of the present study was therefore to compare the articular contact area of the wrist joint between before and after the S-K method for DRUJ disorders. METHODS: The SK method was performed for 15 patients with DRUJ osteoarthritis and ulnar impaction syndrome. We calculated the Mayo Wrist Score as the patient's clinical findings and created 3-dimensional bone models of cases in which the S-K method was performed and calculated the contact area and shift in the center of the contact area using customized software. RESULTS: The Mean modified Mayo Wrist Score improved significantly from 60.3 preoperatively to 80.3 postoperatively (P < 0.01). Scaphoid contact area to the radius increased significantly from 112.6 ± 37.0 mm2 preoperatively to 127.5 ± 27.8 mm2 postoperatively (P = 0.03). Lunate contact area to radius-ulna was 121.3 ± 43.3 mm2 preoperatively and 112.5 ± 37.6 mm2 postoperatively, but this decrease was not significant (P = 0.38). Contact area ratio of scaphoid to lunate increased significantly from 1.01 ± 0.4 preoperatively to 1.20 ± 0.3 postoperatively (P = 0.02). Postoperative translations of the center of the scaphoid and lunate contact areas were decomposed into ulnar and proximal directions. Ulnar and proximal translation distances of the scaphoid contact area were 0.8 ± 1.7 mm and 0.4 ± 0.6 mm, respectively, and those of the lunate contact area were 1.1 ± 1.7 mm and 0.4 ± 1.1 mm, respectively. This study revealed changes in wrist contact area and center of the contact area before and after the S-K method. CONCLUSION: These results may accurately indicate changes in wrist joint contact area from pre- to postoperatively using the S-K method for patients with DRUJ disorder. Evaluation of changes in contact area due to bone surface modeling of the wrist joint using 3DCT images may be useful in considering surgical methods.

A comparison between IBEX bone health applied to digital radiographs and dual-energy X-ray absorptiometry at the distal-third and ultra-distal regions of the radius.

BACKGROUND: In an ageing population, low impact fragility fractures are becoming increasingly common. However, fracture risk can be reduced where low bone density can be identified at an early stage. In this study we aim to demonstrate that IBEX Bone Health (IBEX BH) can provide a clinically useful prediction from wrist radiographs of aBMD and T-score at the ultra-distal (UD) and distal-third (DT) regions of the radius. METHODS: A 261-participant single-centre, non-randomised, prospective, study was carried out to compare a) IBEX BH, a quantitative digital radiography software device, to b) Dual-energy X-ray Absorptiometry (DXA). A total of 257 participants with wrist digital radiograph (DR), forearm DXA pairs were included in the analysis after exclusions. RESULTS: The adjusted R2 value for IBEX BH outputs to the radial areal bone mineral density (aBMD) produced by a GE Lunar DXA system for the UD region is 0.87 (99% Confidence Interval (CI) [0.84, 0.89]). The adjusted R2 value for IBEX BH outputs to aBMD for the DT region is 0.88 (99% CI [0.85, 0.90]). The Area Under the Receiver Operating Characteristic curve (AUC) for the forearm T-score ≤ - 2.5 risk prediction model at the UD region is 0.95 (99% CI [0.93, 0.98]). The AUC for the forearm T-score ≤ - 2.5 risk prediction model at the DT region is 0.98 (99% CI [0.97, 0.99]). CONCLUSION: From a DR of the wrist, IBEX BH provides a clinically useful i) estimate of aBMD at the two regions of interest on the radius and ii) risk prediction model of forearm T-score ≤ - 2.5 at the UD and DT regions.

Three-dimensional analysis of bone site grafting on the upper extremity on computed tomography scans.

PURPOSE: To perform a quantitative analysis of the amount of cancellous bone in the distal radius and olecranon process by segmentation of computed tomographic scans. As a secondary analysis, the bone density by Hounsfield units was evaluated at the same sites. METHODS: Computed tomography angiography images of the upper extremity were analyzed using 3-D Slicer™ medical imaging software. Bone volume (cm3) and density (Hounsfield units) from the cancellous bone between the distal radius and the olecranon process were compared by creating an advanced three-dimensional model. The images were analyzed in duplicate, and an intraclass correlation was performed to assess measurement consistency. RESULTS: Twenty subjects were included. A total volume of 5.01 ± 1.21 cm3 and 5.81 ± 1.61 cm3 for the distal radius and the olecranon process (p < .0001), respectively, was found. Regarding Hounsfield units, the density of the olecranon process was 303.1 ± 73.26, and the distal radius was 206.5 ± 63.73 (p < .0001). All intraclass correlation coefficients were >0.992. CONCLUSION: These results suggest that the olecranon process has a greater volume and a higher bone mineral density than the distal radius. With these results, the surgeon will have the ability to decide the quantity and quality of bone grafts according to the surgical procedure.

An Automatic Method for Elbow Joint Recognition, Segmentation and Reconstruction.

Elbow computerized tomography (CT) scans have been widely applied for describing elbow morphology. To enhance the objectivity and efficiency of clinical diagnosis, an automatic method to recognize, segment, and reconstruct elbow joint bones is proposed in this study. The method involves three steps: initially, the humerus, ulna, and radius are automatically recognized based on the anatomical features of the elbow joint, and the prompt boxes are generated. Subsequently, elbow MedSAM is obtained through transfer learning, which accurately segments the CT images by integrating the prompt boxes. After that, hole-filling and object reclassification steps are executed to refine the mask. Finally, three-dimensional (3D) reconstruction is conducted seamlessly using the marching cube algorithm. To validate the reliability and accuracy of the method, the images were compared to the masks labeled by senior surgeons. Quantitative evaluation of segmentation results revealed median intersection over union (IoU) values of 0.963, 0.959, and 0.950 for the humerus, ulna, and radius, respectively. Additionally, the reconstructed surface errors were measured at 1.127, 1.523, and 2.062 mm, respectively. Consequently, the automatic elbow reconstruction method demonstrates promising capabilities in clinical diagnosis, preoperative planning, and intraoperative navigation for elbow joint diseases.

Radiographic evaluation of the forelimb bone development in maned wolves (Chrysocyon brachyurus).

This study aimed to assess the fusion of growth plates and the development of secondary ossification centres in the forelimb bones of maned wolves (Chrysocyon brachyurus), contrasting the findings with established data from domestic dogs. Three maned wolves, comprising one male and two females, initially aged between 3 and 4 months, were subjected to monthly radiographic evaluations until 10-11 months of age, followed by bimonthly assessments until 18-19 months of age, encompassing both forelimbs. The closure times of growth plates were observed as follows: supraglenoid tubercle (7-8 months), proximal humerus (17-19 months), distal humerus (8-9 months), medial epicondyle of the humerus (8-9 months), proximal ulna (9-10 months), proximal radius (13-15 months), distal ulna (13-15 months) and distal radius (17-19 months). Statistical analysis revealed significant differences in the areas of secondary ossification centres in the proximal epiphyses of the humerus and radius, respectively, observed from the initial evaluation at 8-9 months and 6-7 months. Conversely, the epiphyses of the supraglenoid tubercle, distal humerus, proximal ulna, distal ulna, medial epicondyle of the humerus and distal radius did not exhibit significant area differences between 3-4 months and 4-5 months, yet notable distinctions emerged at 5-6 months. In summary, while the radiographic appearance of epiphyseal growth plates and secondary ossification centres in maned wolves resembles that of domestic dogs, closure times vary. These findings contribute to understanding the dynamics of epiphyseal growth plates in this species.

Radioscapholunate Arthrodesis for Management of Madelung Deformity: A Case Report.

CASE: A 32-year-old woman with bilateral Madelung deformity presented with severe pain and arthritis of the radiocarpal and distal radioulnar joints. At final follow-up, 17 months for the left and 12 months for the right wrist, she had excellent functional results with no pain. Range of motion was 30° of flexion and 30° of extension with full pronosupination. CONCLUSION: There is paucity in the literature regarding salvage procedures in adults with this deformity. We demonstrate treatment with distal ulna excision and an radioscapholunate arthrodesis. This procedure may be indicated in Madelung deformity and proximal radiocarpal and distal radioulnar joint arthritis.

Biomechanical characterization of the central fibrous region of the forearm interosseous Membrane: Implications for finite element modeling.

The interosseous membrane (IOM) of the forearm plays a crucial role in facilitating forearm function and mechanical load transmission between the radius and ulna. Accurate characterization of its biomechanical properties is essential for developing realistic finite element models of the forearm. This study aimed to investigate the mechanical behavior and material properties of the central fibrous regions of the IOM using fresh frozen cadavers. Ten forearms from five cadavers were dissected, preserving the IOM and identifying the distal accessory band (DAB), central band (CB), and proximal accessory band (PAB). Bone-ligament-bone specimens were prepared and subjected to uniaxial tensile testing, with the loading direction aligned with the fiber orientation. Force-displacement curves were obtained and converted to force-strain and stress-strain curves using premeasured fiber lengths and cross-sectional areas. The results demonstrated distinct mechanical responses among the IOM regions, with the PAB exhibiting significantly lower force-strain behavior compared to the DAB and CB. The derived force-strain and stress-strain relationships provide valuable insights into the regional variations in stiffness and strength of the IOM, highlighting the importance of considering these differences when modeling the IOM in finite element analysis. In conclusion, this study establishes a foundation for the development of advanced finite element models of the forearm that accurately capture the biomechanical behavior of the IOM.

The Use of a Distal Radius Allograft for Severe Glenoid Bone Loss in the Setting of Revision Shoulder Arthroplasty: A Case Report.

CASE: A 71-year-old female patient presented with severe glenoid bone loss and deformity after 2 subsequent failed arthroplasty procedures because of baseplate failures. The patients then underwent a conversion from reverse shoulder arthroplasty to hemiarthroplasty, while using a distal radius allograft to augment the deformed glenoid. At the 2-year follow-up, the patient reported minimal pain and satisfactory outcomes. CONCLUSION: This case presents the distal radius as a potentially useful allograft option for augmenting severe glenoid bone loss in the setting of revision shoulder arthroplasty.

Reconstruction of congenital pseudarthrosis of the radius with a vascularized tibial periosteal transplant: A case report.

Congenital pseudarthrosis of the forearm poses a considerable challenge because of its rarity. The objective of this report is to introduce a novel surgical technique for its treatment. Here, we document a case of congenital pseudarthrosis of the radius in a 3-year-old boy diagnosed with type-1 neurofibromatosis. The surgical treatment involved the excision of approximately 9 cm of native radial periosteum and a bifocal radius osteotomy, which was supplemented with a vascularized tibial periosteal transplant to facilitate bone healing. Anastomosis between the anterior tibial vessels and radial vessels was performed. No immediate or late postoperative complications were observed. After 3 weeks, a robust callus formation was observed, and during a follow-up examination 3 years and 4 months later, a wide range of active forearm rotation was noted. This report suggests that vascularized periosteal flaps show promise as a viable treatment option for congenital pseudarthrosis of the forearm. They offer an alternative to vascularized fibular grafts or single-bone forearm constructs.

Insights into digit evolution from a fate map study of the forearm using Chameleon, a new transgenic chicken line.

The cellular and genetic networks that contribute to the development of the zeugopod (radius and ulna of the forearm, tibia and fibula of the leg) are not well understood, although these bones are susceptible to loss in congenital human syndromes and to the action of teratogens such as thalidomide. Using a new fate-mapping approach with the Chameleon transgenic chicken line, we show that there is a small contribution of SHH-expressing cells to the posterior ulna, posterior carpals and digit 3. We establish that although the majority of the ulna develops in response to paracrine SHH signalling in both the chicken and mouse, there are differences in the contribution of SHH-expressing cells between mouse and chicken as well as between the chicken ulna and fibula. This is evidence that, although zeugopod bones are clearly homologous according to the fossil record, the gene regulatory networks that contribute to their development and evolution are not fixed.

Automated Determination of Morphometric Parameters of the Human Radius Based on the Results of Its Computed Tomography.

A fundamentally new software method for automated measurement of morphometric parameters of computed tomographic image of the human radius has been designed. The parameters obtained by manual morphometry of computed tomograms using the RadiAnt DICOM Viewer software were compared with the results of the software product developed by us. The relative error in the measurement of morphometric parameters was about 10%. In the future, the presented software method of automated determination of morphometric parameters of the bone will enable modeling of individual prosthesis of the head of the radius based on the results of computed tomograms with consideration of the structural features of the human radius.

3D-printed porous zinc scaffold combined with bioactive serum exosomes promotes bone defect repair in rabbit radius.

Currently, the repair of large bone defects still faces numerous challenges, with the most crucial being the lack of large bone grafts with good osteogenic properties. In this study, a novel bone repair implant (degradable porous zinc scaffold/BF Exo composite implant) was developed by utilizing laser melting rapid prototyping 3D printing technology to fabricate a porous zinc scaffold, combining it under vacuum conditions with highly bioactive serum exosomes (BF EXO) and Poloxamer 407 thermosensitive hydrogel. The electron microscope revealed the presence of tea saucer-shaped exosomes with a double-layered membrane structure, ranging in diameter from 30-150 nm, with an average size of 86.3 nm and a concentration of 3.28E+09 particles/mL. In vitro experiments demonstrated that the zinc scaffold displayed no significant cytotoxicity, and loading exosomes enhanced the zinc scaffold's ability to promote osteogenic cell activity while inhibiting osteoclast activity. In vivo experiments on rabbits indicated that the hepatic and renal toxicity of the zinc scaffold decreased over time, and the loading of exosomes alleviated the hepatic and renal toxic effects of the zinc scaffold. Throughout various stages of repairing radial bone defects in rabbits, loading exosomes reinforced the zinc scaffold's capacity to enhance osteogenic cell activity, suppress osteoclast activity, and promote angiogenesis. This effect may be attributed to BF Exo's regulation of p38/STAT1 signaling. This study signifies that the combined treatment of degradable porous zinc scaffolds and BF Exo is an effective and biocompatible strategy for bone defect repair therapy.

Free fibula flap to achieve bone union after congenital pseudoarthrosis of the forearm in neurofibromatosis: Technical report based on 3 cases, and literature review.

Congenital pseudarthrosis of the forearm bones (CPFBs) is rare, with only 106 reported cases, and is frequently associated with neurofibromatosis (NF). Approximately 5% of patients with NF develop pseudarthrosis, and 50% of patients with pseudarthrosis have NF. Achieving bone union is difficult in congenital pseudarthrosis. Many methods have been attempted, including casting, internal fixation with or without grafting, and electrical stimulation, but failure is frequent. Free vascularized fibular flaps (FVFs) have been used to bridge long bone defects since 1975 and in tibial pseudarthrosis since 1979. In CPFB, FVF is more successful than other methods in achieving union and is the current treatment of choice. Here, we presented three cases of forearm pseudarthrosis treated with FVF, reviewed the literature on CPFB, and discussed some technical aspects of FVF treatment. Three cases of congenital pseudoarthrosis were treated with free fibula flaps, diagnosed at ages of 7 years (ulna), 15 months (radius), and 9 years (radius and ulna). Two flaps were stabilized with intramedullary wires and latterly, one with compression plates. One persistent nonunion received revision nonvascularized bone grafting and plating. All patients achieved union by 11 months after index surgery. Reconstruction with vascularized fibula is the treatment of choice because it offers the highest published union rates and good functional results. Complete resection of the affected bone and stable fixation, latterly with compression plates are critical to success. Surgery is technically demanding, and complications are common. Secondary surgery may be required, but outcomes are favorable. LEVEL OF EVIDENCE: IV.

Use of F18 bioglass putty for induced membrane technique in segmental bone defect of the radius in rabbits.

PURPOSE: To evaluate the inductive capacity of F18 bioglass putty on the induced membrane technique in a segmental bone defect of the rabbit's radius. METHODS: Ten female Norfolk at 24 months of age were used. The animals were randomly separated based on postoperative time points: five rabbits at 21 and four at 42 days. A 1-cm segmental bone defect was created in both radii. The bone defects were filled with an F18 bioglass putty. RESULTS: Immediate postoperative radiographic examination revealed the biomaterial occupying the segmental bone defect as a well-defined radiopaque structure with a density close to bone tissue. At 21 and 42 days after surgery, a reduction in radiopacity and volume of the biomaterial was observed, with particle dispersion in the bone defect region. Histologically, the induced membrane was verified in all animals, predominantly composed of fibrocollagenous tissue. In addition, chondroid and osteoid matrices undergoing regeneration, a densely vascularized tissue, and a foreign body type reaction composed of macrophages and multinucleated giant cells were seen. CONCLUSIONS: the F18 bioglass putty caused a foreign body-type inflammatory response with the development of an induced membrane without expansion capacity to perform the second stage of the Masquelet technique.

Stress shielding following radial head arthroplasty: the impact of preoperative bone quality.

BACKGROUND: We sought to assess if the medullary diameter to cortical width ratio (MD:CW), canal flair index (CFI), and canal fill (CF) of the proximal radius were associated with the presence of stress shielding (SS) after a MoPyC radial head arthroplasty. MATERIALS AND METHODS: We conducted a retrospective, international, multicenter (4 centers) study. A total of 100 radial head arthroplasties in 64 women and 36 men with a mean age of 58.40 years ± 14.90 (range, 25.00-91.00) were included. Radiographic measurements, including MD:CW, CFI, CF, and postoperative SS were captured at a mean follow-up of 3.9 years ± 2.8 (range, 0.5-11). RESULTS: SS was identified in 60 patients. Mean preoperative MD:CW, CFI, and CF were 0.55 ± 0.09, 1.05 ± 0.18, and 0.79 ± 0.11, respectively. The presence of SS was significantly associated with MD:CW (adjusted odds ratio = 13.66; P = .001), and expansion of the stem (adjusted odds ratio = 3.78; P = .001). The amount of the SS was significantly correlated with expansion of the stem (aß 4.58; P < .001). CONCLUSIONS: Our study found that MD:CW was an independent risk factor of SS after MoPyc radial head arthroplasty. Autoexpansion of the MoPyc stem significantly increased the risk of SS and its extent. Further studies involving multiple implants designs are needed to confirm the preliminary observations presented in the current study.

Conservative treatment of congenital radial head subluxation and non-traumatic elbow locking: A case report.

Congenital radial head subluxation is relatively rare and may be overlooked due to mild symptoms. The diagnosis mainly relies on imaging and history. Observation is an option for those with insignificant symptoms, while surgical intervention, such as ulnar osteotomy or arthroscopy, is often required when dysfunction exists. A 30-year-old man was admitted with congenital radial head dislocation, which was treated with manipulative repositioning. During follow-up, the patient regained the original mobility of the elbow joint and had no recurrence of dislocation. In conclusion, in adults with congenital dislocation of the radial head, we recommend conservative treatment as a first step.

Nursemaid's elbow: Radial head subluxation injuries in children.

ABSTRACT: Radial head subluxation, or nursemaid's elbow, is a common orthopedic complaint in children and often is the result of a pulling injury to the affected arm. Although this injury largely is a clinical diagnosis, different imaging modalities may be used to identify it and confirm successful reduction. Multiple manipulative techniques can be used to treat this injury and methods are generally specific to clinician preference. This article reviews the causes, evaluation, and management of radial head subluxation.

Three cases of dogs with osteosarcoma of the forelimb treated with liquid nitrogen for limb-sparing surgery using autologous bone.

Osteosarcoma treatment with limb-sparing surgery using liquid nitrogen can be applied to canine patients experiencing diminished quality of life after leg amputation. In particular, forelimb amputation may affect gait more than hindlimb amputation. In this study, limb-sparing surgery using liquid nitrogen was applied to primary osteosarcomas arising in the proximal scapula of a Welsh Corgi, the proximal humerus of a Golden Retriever, and the distal radius of a Great Pyrenees, according to the protocol of Tsuchiya et al. In all cases, postoperative radiographic examination revealed bone union between the treated and matrix bones. All patients recovered their gait postoperatively. These results suggest that limb-sparing surgery using liquid nitrogen-treated autologous bone is an effective option for patients with osteosarcoma.

Anatomical features of the proximal end of the radius and its implications for implant design.

PURPOSE: The proximal radio-ulnar joint allows supination and pronation of the forearm and the humeroradial joint allows flexion and extension movements at the elbow joint. Although the proximal end of the radius is less common than other fractures, it is more common nowadays due to the prolongation of life expectancy, increased incidence of osteoporosis. There have been reports in the literature that success has not been achieved due to the lack of anatomical fit of the prosthesis. Knowledge of the morphometric features of the proximal end of the radius is important for the design of anatomically and biomechanically appropriate prostheses. METHODS: In this study, measurements of head and neck of radius, and radial tuberosity were measured in 80 dry radii. Parameters important for prosthesis design were analysed and their correlations examined. RESULTS: The shapes of radial head was found 36% oval and 64% circular. The mean heights of the radial head at anterior, posterior, medial, and lateral sides were 8.52 ± 1.32 mm, 9.02 ± 1.23 mm, 9.20 ± 1.59 mm, 8.05 ± 1.13 mm, respectively. The mean depth of articular facet were 1.85 ± 0.37 mm. It was determined that there was no high correlation between the parameters affecting the prosthesis design. CONCLUSIONS: Morphological and morphometric features of the proximal radius are important for prosthesis design and implantation. The ideal radial head prosthesis design is challenging due to numerous parameters, wide ranges and low correlation, although modular designs facilitate compatibility. The widespread use of 3D printing technologies is expected to reduce the potential complications associated with prosthesis applications.