A Novel Technique to Assess Distal Radioulnar Joint Stability Using Increasing Torque

Sex differences in wrist strength: a systematic review

Sex differences in strength have been attributed to differences in body anthropometrics and composition; these factors are often ignored when generating workplace guidelines. These differences directly impact the upper extremity, leaving female workers exposed to injury risk. The wide range of tools and techniques for measuring upper extremity strength presents a challenge to ergonomists and work task designers; collating outcomes to provide a clear outlook of differences between males and females is essential and the purpose of this work. Four online databases were searched (PROSPERO ID: CRD42022339023) with a focus on articles assessing sex differences in wrist strength. A total of 2,378 articles were screened for relevancy; 25 full-text articles were included in this systematic review. Articles examined movement pairs (ulnar/radial deviation, pronation/supination, and flexion/extension), as well as contraction types (isometric and isokinetic) to observe sex differences in wrist strength. Across all articles, females produced ∼60-65% of male flexion/extension strength, ∼55-60% pronation/supination strength, and ∼60-70% ulnar/radial deviation strength. Overall, females presented lower strength-producing abilities than males, but when considering strength relative to body mass, male-female differences were less pronounced and occasionally females surpassed male strength metrics; typically, this occurred during flexion/extension, particularly in isokinetic contractions. This review has identified a scarcity of articles examining ulnar/radial deviation, pronation/supination, as well as isokinetic contractions; these are needed to supplement workplace exposure guidelines.

Structurally intact and functionally incompetent foveal triangular fibrocartilage complex injuries : an under-recognized spectrum of injury

Injury to the triangular fibrocartilage complex (TFCC) may result in ulnar wrist pain with or without instability. One component of the TFCC, the radioulnar ligaments, serve as the primary soft-tissue stabilizer of the distal radioulnar joint (DRUJ). Tears or avulsions of its proximal, foveal attachment are thought to be associated with instability of the DRUJ, most noticed during loaded pronosupination. In the absence of detectable instability, injury of the foveal insertion of the radioulnar ligaments may be overlooked. While advanced imaging techniques such as MRI and radiocarpal arthroscopy are well-suited for diagnosing central and distal TFCC tears, partial and complete foveal tears without instability may be missed without a high degree of suspicion. While technically challenging, DRUJ arthroscopy provides the most accurate method of detecting foveal abnormalities. In this annotation the spectrum of foveal injuries is discussed and a modified classification scheme is proposed.Cite this article: Bone Joint J 2023;105-B(1):5-10.

Application of force-monitor ultrasonography to assess distal radioulnar joint instability in patients with triangular fibrocartilage complex injury

Introduction

In this study, we evaluated the differences and measurement accuracy in the force-displacement relationship of the distal radioulnar joint (DRUJ) between patients with triangular fibrocartilage complex (TFCC) injury and healthy controls using force-monitor ultrasonography.

Methods

This study included 11 TFCC injury patients and 22 healthy controls. We evaluated differences in the force-displacement relationship of the DRUJ in these patients using force-monitor ultrasonography. Cyclic compression was applied to the dorsal surface of the ulnar head. Distance between the dorsal surface of the distal radius and ulnar head at the DRUJ level was measured in the initial and pressed-down positions. Changes in radioulnar displacement, applied force, and displacement-to-force ratio were measured. Furthermore, we compared the parameters between the affected and unaffected wrists and between TFCC injury patients and controls.

Results

The radioulnar displacement and displacement-to-force ratio were significantly larger in the affected wrists than in the unaffected wrists (P = 0.003 and P = 0.02). The affected/unaffected side ratio of radioulnar displacement and displacement-to-force ratio were significantly larger in the TFCC injury patients than in the controls (P = 0.003 and P = 0.02). The area under the curve was 0.82 for the affected/unaffected ratio of the radioulnar displacement. The optimal cutoff value indicated by the receiver-operating characteristic curve for the affected/unaffected ratio of the radioulnar displacement was 1.71; the sensitivity and specificity were 82% and 86%, respectively.

Conclusions

Assessing the DRUJ instability with force-monitor ultrasonography may help identify TFCC-injured wrists.

Distal Radioulnar Joint Instability: Diagnosis and Treatment

Distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) tears are more usual than estimated and are frequently overlooked. Diagnosis is often clinical, which can be confirmed using computed tomography (CT) scan and magnetic resonance imaging (MRI). In doubtful cases, bilateral computed tomography in neutral forearm rotation, supination, and pronation should also be performed. Wrist arthroscopy can be diagnostic and therapeutic for ulnar-sided wrist pain. Two systematic reviews showed equivalent outcomes between open and arthroscopic repair of the TFCC. There is scant proof to advise one technique over the other in clinical practice. TFCC repair and reconstruction are contraindicated when there is a bony deformation of the radius or ulna or osteoarthritis of the DRUJ. With the advancement of implant arthroplasty, salvage procedures are less desirable. Constrained distal radioulnar arthroplasty is stable, and the longevity is encouraging.

Assessment of distal radioulnar joint stability in healthy subjects: Changes with dominant hand, sex, and age

This study aimed to elucidate the differences in distal radioulnar stability in dominant/nondominant hand, sex, and age. Bilateral wrists of 60 healthy subjects were evaluated using force-monitoring ultrasonography. This apparatus was developed to apply cyclic compression and measure applied force to displacement during an ultrasound exam. The transducer was placed on the dorsal side of the distal radioulnar joint, and the center of the ulnar head was displayed on the monitor. The distance between the dorsal surface of the distal radius and the ulnar head was measured at an initial and at a pressed-down position. The radioulnar displacement, applied force to displacement, and displacement-to-force ratio were evaluated. The results were compared between the dominant and nondominant hands, and between males and females, and among different age groups. There were no significant differences in the parameters between the dominant and nondominant hands. The applied force to displacement was significantly greater in the male group compared with the female group. There were significant effects for the different age groups in all parameters (displacement: F = 3.67, p = .008; applied-force: F = 3.08, p = .019; displacement-to-force ratio: F = 4.66, p = .002). Our results indicated that the stability of distal radioulnar joint differed depending on age and sex. Age and sex should be considered when assessing distal radioulnar joint stability.