Common treatments and procedures used for fractures of the distal radius and scaphoid: A review

Stability Analysis of Plate-Screw Fixation for Femoral Midshaft Fractures

An understanding of the biomechanical characteristics and configuration of flexible and locked plating in order to provide balance stability and flexibility of implant fixation will help to construct and promote fast bone healing. The relationship between applied loading and implantation configuration for best bone healing is still under debate. This study aims to investigate the relationship between implant strength, working length, and interfragmentary strain (εIFM) on implant stability for femoral midshaft transverse fractures. The transverse fracture was fixed with a fragment locking compression plate (LCP) system. Finite element analysis was performed and subsequently characterised based on compression loading (600 N up to 900 N) and screw designs (conventional and locking) with different penetration depths (unicortical and bicortical). Strain theory was used to evaluate the stability of the model. The correlation of screw configuration with screw type shows a unicortical depth for both types (p < 0.01) for 700 N and 800 N loads and (p < 0.05) for configurations 134 and 124. Interfragmentary strain affected only the 600 N load (p < 0.01) for the bicortical conventional type (group BC), and the screw configurations that were influenced were 1234 and 123 (p < 0.05). The low steepness of the slope indicates the least εIFM for the corresponding biomechanical characteristic in good-quality stability. A strain value of ≤2% promotes callus formation and is classified as absolute stability, which is the minimum required value for the induction of callus and the maximum value that allows bony bridging. The outcomes have provided the correlation of screw configuration in femoral midshaft transverse fracture implantation which is important to promote essential primary stability.

[Research progress in the treatment of distal radius fractures assisted by wrist arthroscopy]

Objective

To review the research progress of wrist arthroscopy assisted treatment of distal radius fractures.

Methods

To summarize and describe the anatomical characteristics and fracture classification of the distal radius, indications and contraindications of wrist arthroscopy-assisted treatment, surgical methods, and associated soft tissue injuries, and summarize the advantages and disadvantages of the operation through a large number of literature at home and abroad on the treatment of distal radius fractures assisted by wrist arthroscopy.

Results

Wrist arthroscopy as a minimally invasive technique for the treatment of distal radius fractures, compared with traditional surgery, can accurately observe intra-articular damage and perform operations under the microscope to avoid secondary damage to blood vessels, nerve, and tendon, etc., and can achieve one-stage repair and reconstruction by repairing the ligament, trigonal fibrocartilage complex, and carpal dislocation. It has the advantages of less trauma, fast postoperative recovery, extensive indications, fewer complications, and satisfactory effectiveness.

Conclusion

Wrist arthroscopy has advantages that traditional X-ray film, CT, MRI, and arthrography examinations do not have. Moreover, wrist arthroscopy has achieved satisfactory effectiveness in the adjuvant treatment of intra-articular distal radius fractures.

Outcomes of Unstable Scaphoid Nonunion With Segmental Defect Treated With Plate Fixation and Autogenous Cancellous Graft

PURPOSE

Treatment of scaphoid nonunion with a segmental defect presents a challenging clinical problem. Various techniques have been proposed, often involving structural grafting with vascularized and nonvascularized bone. The authors hypothesize that satisfactory clinical and radiographic outcomes are possible with a relatively simplified technique of volar plate fixation with autogenous, purely cancellous graft.

METHODS

The authors performed a retrospective review of 34 patients with scaphoid nonunions with segmental defects, treated with plate fixation and purely cancellous bone grafting. Cases with avascular necrosis were excluded. Surgical management included a volar incision, reduction, bone grafting from the ipsilateral distal radius and/or olecranon, and application of a volar locking plate. Postoperative outcome measures included time to union based on computed tomography, return to work and sports, patient-reported pain and disability scores, grip strength, and range of motion.

RESULTS

Thirty-four patients with an average age of 31 years (range, 16-55 years) were treated with volar plate fixation and cancellous grafting, an average of 34 months after initial injury. Twenty-six patients (76%) were treated for nonunion at the scaphoid waist, 7 (21%) at the proximal pole, and 1 (3%) at the distal pole. Mean final follow-up was 18.7 months (range, 12-34 months). When union was defined by computed tomography evidence of healing, 2 (6%) scaphoids healed by 6 weeks after surgery, 28 (82%) healed by 12 weeks, and 100% healed by 18 weeks. Mean Disabilities of the Arm, Shoulder, and Hand score improved from 27.1 ± 7.3 before surgery to 11.8 ± 5.8 after surgery. Grip strength, corrected for hand dominance, improved from 77.5% of the nonsurgical side before surgery to 90.5% after surgery. All employed patients returned to work, although 3 (9%) did not return to full capacity.

CONCLUSIONS

The combination of scaphoid plate fixation and pure cancellous bone grafting for scaphoid nonunion with segmental defects yields reliable union rates and good patient outcomes. Autogenous cancellous grafting may be an alternative to more technically demanding or morbid grafting procedures for the treatment of scaphoid nonunion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Incorporating Germanium Oxide into the Glass Phase of Novel Zinc/Magnesium-Based GPCs Designed for Bone Void Filling: Evaluating Their Physical and Mechanical Properties

The structural role of Germanium (Ge), when substituting for Zinc (Zn) up to 8 mol % in the 0.48SiO₂⁻0.12CaO⁻0.36ZnO⁻0.04MgO glass series, was investigated with respect to both the glass chemistry and also the properties of glass polyalkenoate cements (GPCs) manufactured from them. The Network connectivity (NC) of the glass was calculated to increase from 1.83 to 2.42 with the addition of GeO₂ (0⁻8 mol %). Differential thermal analysis (DTA) results confirmed an increase in the glass transition temperature (T_g) of the glass series with GeO₂ content. X-ray photoelectron spectroscopy (XPS) showed an increase in the ratio of bridging oxygens (BO) to non-bridging oxygens (NBO) with the addition of GeO₂, supporting the NC and DTA results. ²⁹Si magic angle spinning nuclear magnetic resonance spectroscopy (²⁹Si MAS-NMR) determined a chemical shift from -80.3 to -83.7 ppm as the GeO₂ concentration increased. These ionomeric glasses were subsequently used as the basic components in a series of GPCs by mixing them with aqueous polyacrylic acid (PAA). The handling properties of the GPCs resulting were evaluated with respect to the increasing concentration of GeO₂ in the glass phase. It was found that the working times of these GPCs increased from 3 to 15 min, while their setting times increased from 4 to 18 min, facilitating the injectability of the Zn/Mg-GPCs through a 16-gauge needle. These Ge-Zn/Mg-GPCs were found to be injectable up to 96% within 12 min. Zn/Mg-GPCs containing GeO₂ show promise as injectable cements for use in bone void filling.

The biomechanical analysis of three-dimensional distal radius fracture model with different fixed splints

BACKGROUND

The distal radius fracture is one of the common clinical fractures. At present, there are no reports regarding application of the finite element method in studying the mechanism of Colles fracture and the biomechanical behavior when using splint fixation.

OBJECTIVE

To explore the mechanism of Colles fracture and the biomechanical behavior when using different fixed splints.

METHODS

Based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a 3-D distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body.

RESULTS

Using the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination. By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression.

CONCLUSION

The anatomical splint is the most effective for fixing and curing the fracture. The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint.