The Effect of Distal Radius Fractures on 3-Dimensional Joint Congruency

Ligament reconstruction for distal radioulnar joint instability with the biomechanical analysis: A case report

RATIONALE

The aim of the study is to evaluate the clinical effects and feasibility on chronic distal radioulnar unstable joint (DRUJ) under wrist arthroscope triangular fibrocartilage complex (TFCC) repair and reconstruction. The biomechanical characteristics of the recovery process after treatment were analyzed using finite element modeling.

PATIENT CONCERNS

A patient with chronic DRUJ instability was treated with reconstruction of the distal radioulnar ligament using the Adams Berger method. Piano sign and forearm rotation tests were used to evaluate the function of the DRUJ. Grip power, range of motion, and visual analog scale scores were recorded at the last follow-up. Joint function was evaluated by the disability of the arm, shoulder, and hand score. A geometric model for the surgical repair of TFCC damage, meshing in finite element simulation, and stress distribution of the repaired ligament during forearm rotation were analyzed by finite element simulation.

DIAGNOSES

The diagnosis was confirmed as chronic DRUJ instability.

INTERVENTIONS AND OUTCOMES

The patient had no postoperative complications and was followed-up for 6 months. Stability was achieved in all patients. The results of the stress and forearm rotation tests are negative. At the last follow-up, the grip power, disability of the arm, shoulder, and hand score, visual analog scale score, and range of motion of the wrist were significantly improved compared with the preoperative values (P < .05).

LESSONS

TFCC repair and reconstruction under wrist arthroscopy can effectively treat chronic DRUJ and improve wrist function. Our study established a three-dimensional finite element model of the entire DRUJ, which provided a digital visual platform for simulating the biomechanical features of the TFCC, DRUJ, and other structures in different states. This study demonstrated that the rotation angle of the wrist joint should be confined within 75° for a short period after surgery to avoid tearing the tendon as a result of excessive force. It also provides an intuitive simulation tool for the design of TFCC repair and the evaluation of curative effects.

Use it or lose it: The relationship between two image-based biomarkers in better understanding osteoarthritis progression in the wrist

Bone tissue is influenced by its mechanical environment and adapts in response to its mechanical load. This is supported by studies analyzing bone adaptation in the knee and hip. Changes to the bone have also been found to precede cartilage degeneration in diseases such as osteoarthritis (OA). Our objective was to demonstrate the relationship between joint contact and bone density in the wrists of healthy adults. Static CT scans with a calibration phantom were taken to obtain measures of bone mineral density (vBMD) in 3 normalized depths; 0 - 2.5, 2.5 - 5, and 5 - 7.5 mm. Participants underwent a four-dimensional CT scan (4DCT) while performing maximum wrist extension to maximum wrist flexion. 3D bone models of the distal radius, scaphoid, and lunate were made, and analyzed vBMD and joint contact area (JCA) in the radiolunate (RL) and radioscaphoid (RS) joints separately. Correlation coefficients were calculated where vBMD was the dependent variable, and kinematic JCA throughout every 10 degrees of motion were the independent variables. Statistically significant independent variables associated with vBMD were assessed using a regression model and were entered in steps; (1) significant correlations, (2) sex, and (3) age.An increase in vBMD was significantly, positively associated with an increase in JCa. Notably, in the deeper regions (5 - 7.5 mm) of the radius that is primarily composed of trabecular bone. Sex contributed to the variance in vBMD, while age did not. Subchondral bone changes are influenced by wrist position, demonstrating that the wrist serves to bear load similar to the knee and hip.

The Utility of Quantitative CT (QCT) to Detect Differences in Subchondral Bone Mineral Density Between Healthy People and People with Pain Following Wrist Trauma

The mechanisms underlying chronic pain development following musculoskeletal trauma are complex and multifactorial. In their search, some researchers are turning to the subchondral bone as a potential contributor to pain due to its vascularity, using a depth-specific imaging technique. However, this technique has been mainly used in the knee. We propose the use of a quantitative computed tomography (QCT) depth-specific analysis to measure subchondral bone following wrist trauma. Ten participants (n=5 post-trauma; n=5 healthy) underwent bilateral CT scans of their wrist accompanied by a calibration phantom with known densities. Average subchondral vBMD was studied at three depths from the subchondral surface (0 to 2.5, 2.5 to 5, 5 to 7.5mm) according to radial articular surface contact in both wrists of each participant. Percentage differences and Cohen's d effect sizes were calculated to analyze bilateral vBMD and vBMD differences between groups. This image-based tool demonstrated subject-specific, depth-specific, and joint-specific measures of vBMD within the wrist. This methodology highlighted the differences between depth-specific vBMD in healthy people and people who have experienced wrist trauma. Overall, the healthy cohort demonstrated higher vBMD across all three depths and both articular surfaces. This imaging technique further distinguished between subchondral cortical and trabecular bone, wherein clinical implications can be drawn from these distinctions in future work. Our study therefore supports the utility of a QCT imaging technique in detecting differences in depth-specific vBMD in the wrist.

Four-Dimensional Computed Tomography to measure distal radial-ulnar and radio-carpal joint congruency following distal radius fractures

Four-dimensional computed tomography (4DCT) allows for the assessment of the wrist contact mechanics and kinematics during motion. The purpose of this study was to employ 4DCT to measure the differences in joint surface area (JSA) (3D joint space) at the radioscaphoid, radiolunate, and distal radioulnar joints between a cohort of participants with a distal radius fracture (DRF) and an age-matched cohort of healthy participants. Our results indicated that following a DRF, there was a 20% decrease in JSA at the DRUJ when compared to the healthy (control) cohort. This study demonstrated the use of a non-invasive tool to examine wrist contact mechanics.