Clinical and Non-Clinical Aspects of Distal Radioulnar Joint Instability

Untreated distal radioulnar joint (DRUJ) injuries can give rise to long lasting complaints. Although common, diagnosis and treatment of DRUJ injuries remains a challenge. The articulating anatomy of the distal radius and ulna, among others, enables an extensive range of forearm pronosupination movements. Stabilization of this joint is provided by both intrinsic and extrinsic stabilizers and the joint capsule. These structures transmit the load and prevent the DRUJ from luxation during movement. Several clinical tests have been suggested to determine static or dynamic DRUJ stability, but their predictive value is unclear. Radiologic evaluation of DRUJ instability begins with conventional radiographs in anterioposterior and true lateral view. If not conclusive, CT-scan seems to be the best additional modality to evaluate the osseous structures. MRI has proven to be more sensitive and specific for TFCC tears, potentially causing DRUJ instability. DRUJ instability may remain asymptomatic. Symptomatic DRUJ injuries treatment can be conservative or operative. Operative treatment should consist of restoration of osseous and ligamenteous anatomy. If not successful, salvage procedures can be performed to regain stability

A review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering

Despite its intrinsic ability to regenerate form and function after injury, bone tissue can be challenged by a multitude of pathological conditions. While innovative approaches have helped to unravel the cascades of bone healing, this knowledge has so far not improved the clinical outcomes of bone defect treatment. Recent findings have allowed us to gain in-depth knowledge about the physiological conditions and biological principles of bone regeneration. Now it is time to transfer the lessons learned from bone healing to the challenging scenarios in defects and employ innovative technologies to enable biomaterial-based strategies for bone defect healing. This review aims to provide an overview on endogenous cascades of bone material formation and how these are transferred to new perspectives in biomaterial-driven approaches in bone regeneration

Deficiency of inducible and endothelial nitric oxide synthase results in diminished bone formation and delayed union and nonunion development

Background\u3cbr/\u3eBetween 5% and 10% of all fractures fail to heal adequately resulting in nonunion of the fracture fragments. This can significantly decrease a patient's quality of life and create associated psychosocial and socio-economic problems.\u3cbr/\u3eNitric oxide (NO) and nitric oxide synthases (NOS) have been found to be involved in fracture healing, but until now it is not known if disturbances in these mechanisms play a role in nonunion and delayed union development. In this study, we explored the role of endothelial and inducible NOS deficiency in a delayed union model in mice.\u3cbr/\u3eMaterials and methods\u3cbr/\u3eA 0.45 mm femur osteotomy with periosteal cauterization followed by plate-screw osteosynthesis was performed in the left leg of 20–24 week old wild type, Nos2−/− and Nos3−/− mice. Contralateral unfractured legs were used as a control. Callus volume was measured using micro-computed tomography (μCT) after 28 and 42 days of fracture healing. Immuno histochemical myeloperoxidase (MPO) staining was performed on paraffin embedded sections to assess neutrophil influx in callus tissue and surrounding proximal and distal marrow cavities of the femur. After 7 and 28 days of fracture healing, femurs were collected for amino acid and RNA analysis to study arginine-NO metabolism.\u3cbr/\u3eResults\u3cbr/\u3eWith μCT, delayed union was observed in wild type animals, whereas in both Nos2−/− and Nos3−/− mice nonunion development was evident. Both knock-out strains also showed a significantly increased influx of MPO when compared with wild type mice. Concentrations of amino acids and expression of enzymes related to the arginine-NO metabolism were aberrant in NOS deficient mice when compared to contralateral control femurs and wild type samples.\u3cbr/\u3eDiscussion and conclusion\u3cbr/\u3eIn the present study we show for the first time that the absence of nitric oxide synthases results in a disturbed arginine-NO metabolism and inadequate fracture healing with the transition of delayed union into a nonunion in mice after a femur osteotomy. Based on these data we suggest that the arginine-NO metabolism may play a role in the prevention of delayed unions and nonunions.\u3cbr/\u3

Early changes in bone density, microarchitecture, bone resorption, and inflammation predict the clinical outcome 12 weeks after conservatively treated distal radius fractures : an exploratory study

Fracture healing is an active process with early changes in bone and inflammation. We performed an exploratory study evaluating the association between early changes in densitometric, structural, biomechanical, and biochemical bone parameters during the first weeks of fracture healing and wrist-specific pain and disability at 12 weeks in postmenopausal women with a conservatively treated distal radius fracture. Eighteen patients (aged 64¿±¿8 years) were evaluated at 1 to 2 and 3 to 4 weeks postfracture, using high-resolution peripheral quantitative computed tomography (HR-pQCT), micro-finite element analysis, serum procollagen type-I N-terminal propeptide (P1NP), carboxy-terminal telopeptide of type I collagen (ICTP), and high-sensitive C-reactive protein (hsCRP). After 12 weeks, patients rated their pain and disability using Patient Rated Wrist Evaluation (PRWE) questionnaire. Additionally, Quick Disability of the Arm Shoulder and Hand (QuickDASH) questionnaire and active wrist range of motion was evaluated. Linear regression models were used to study the relationship between changes in bone parameters and in hsCRP from visit 1 to 2 and PRWE score after 12 weeks. A lower PRWE outcome, indicating better outcome, was significantly related to an early increase in trabecular bone mineral density (BMD) (ß -0.96 [95% CI -1.75 to -0.16], R2¿=¿0.37), in torsional stiffness (-0.14 [-0.28 to -0.004], R2¿=¿0.31), and to an early decrease in trabecular separation (209 [15 to 402], R2¿=¿0.33) and in ICTP (12.1 [0.0 to 24.1], R2¿=¿0.34). Similar results were found for QuickDASH. Higher total dorsal and palmar flexion range of motion was significantly related to early increase in hsCRP (9.62 [3.90 to 15.34], R2¿=¿0.52). This exploratory study indicates that the assessment of early changes in trabecular BMD, trabecular separation, calculated torsional stiffness, bone resorption marker ICTP, and hsCRP after a distal radius fracture provides valuable information regarding the 12-week clinical outcome in terms of pain, disability, and range of motion and validates its use in studies on the process of early fracture healing. © 2014 American Society for Bone and Mineral Research