Intra-articular Pressure in the Distal Radioulnar Joint: A Biomechanical Study.

Purpose: The aim of the study was to use cadaveric models to assess the effect of loading the forearm muscles in different forearm rotations, with or without disruption to the stabilizing components, on the intra-articular pressure of the distal radioulnar joint (DRUJ).

Methods: Ten forearms with no severe osteoarthritis or injury to the DRUJ stabilizers were used. They were placed in a vertical support, and pressure sensors measured pressure within the DRUJ in 5 forearm rotations (neutral, pronation, supination, extension, and flexion) under the following 6 conditions: 1) no loading; 2) loading (at 1/5 of the load per cross-sectional area) with no disruption; 3) loading with disruption of the triangular fibrocartilage complex (TFCC); 4) loading with disruption of the TFCC and ulnar ligaments (ULs); 5) loading with disruption of the TFCC, ULs and interosseous membrane (IM); and 6) loading with disruption of the TFCC, ULs, IM, and pronator quadratus (PQ).

Influence of forearm rotation on the kinetic stabilizing efficiency of the muscles that control the scapholunate joint. Clinical application in proprioceptive and neuromuscular rehabilitation programs.

Background: This study focuses on the relationship between forearm muscles, carpal ligaments, and their impact on scapholunate joint stability across varying forearm rotations. This is crucial for optimizing pre and postoperative rehabilitation strategies for scapholunate joint dysfunction.

Purpose: Our study aims to understand the kinetic influence of forearm muscles on scapholunate joint instability.

Scapholunate and lunotriquetral joint dynamic stabilizers and their role in wrist neuromuscular control and proprioception.

Background: Recent research interest has grown in exploring the role of muscles, isometric contraction, proprioception, and neuromuscular control in addressing dynamic scapholunate and lunotriquetral joint instability, marking a shift in the understanding of wrist stability.

Purpose: To present a comprehensive review of the carpal ligaments anatomy and wrist biomechanics, with a particular focus on the role of proprioception in dynamic carpal stability and their role in managing scapholunate (SL) and lunotriquetral (LTq) dynamic instabilities.

Study Design: We conducted a systematic search of the literature and review of the most relevant papers published and indexed in pubmed, related to wrist biomechanics, proprioception and its contribution to carpal dynamic stability.

Interdisciplinary consensus statements on imaging of DRUJ instability and TFCC injuries.

Objectives: The purpose of this agreement was to establish evidence-based consensus statements on imaging of distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) injuries by an expert group using the Delphi technique.

Methods: Nineteen hand surgeons developed a preliminary list of questions on DRUJ instability and TFCC injuries. Radiologists created statements based on the literature and the authors' clinical experience.

Immunofluorescence analysis of sensory nerve endings in the periarticular tissue of the human elbow joint.

Introduction: To investigate the dynamic aspects of elbow stability, we aimed to analyze sensory nerve endings in the ligaments and the capsule of elbow joints.

Materials And Methods: The capsule with its anterior (AJC) and posterior (PJC) parts, the radial collateral ligament (RCL), the annular ligament (AL), and the ulnar collateral ligament with its posterior (PUCL), transverse (TUCL) and anterior parts (AUCL) were dissected from eleven human cadaver elbow joints. Sensory nerve endings were analyzed in two levels per specimen as total cell amount/ cm after immunofluorescence staining with low-affinity neurotrophin receptor p75, protein gene product 9.

Bilateral Ulnar Deviation Supination Stress Test to Assess Dynamic Scapholunate Instability.

Purpose: We describe a new radiologic test to assess the integrity of the scapholunate ligament in dynamic scapholunate dysfunction.

Methods: A bilateral forearm-holding device was designed to perform a comparative radiographic assessment of the scapholunate joint gap during resisted isometric contraction of the extensor carpi ulnaris muscle with full supination of the forearm. The concept is based on the known scaphoid pronation effect of this muscle.

Ligaments and muscles stabilizing the radio-ulno-carpal joint.

The technical simplicity of the Darrach procedure may explain why it has been so popular. Excising the distal ulna, however, may have potentially undesired consequences to the biomechanics in two areas: the distal radioulnar and the ulno-carpal joints. These conjointly define the radio-ulno-carpal joint (RUCJ).

Interdisciplinary consensus statements on imaging of scapholunate joint instability.

Objectives: The purpose of this agreement was to establish evidence-based consensus statements on imaging of scapholunate joint (SLJ) instability by an expert group using the Delphi technique.

Methods: Nineteen hand surgeons developed a preliminary list of questions on SLJ instability. Radiologists created statements based on the literature and the authors' clinical experience.

Degeneration of the articular disc in the human triangular fibrocartilage complex.

Introduction: Traumatic injuries of the triangular fibrocartilage complex (TFCC) are frequent reasons for ulnar wrist pain. The assessment of the extent of articular disc (AD) degeneration is important for the differentiation of acute injuries versus chronic lesions.

Materials And Methods: The AD of the TFCC of eleven human cadaver wrists was dissected.

Kinetic dysfunction of the wrist with chronic scapholunate dissociation. A cadaver study.

Background: Most laboratory studies investigating scapholunate dissociations are based on normal cadaver arms with serially sectioned ligaments. It is assumed that the kinetic behavior of a ligament-sectioned wrist is similar to a scapholunate dissociation. We tested five cadaver wrists with real injuries.

Immunofluorescence analysis of sensory nerve endings in the interosseous membrane of the forearm.

The human interosseous membrane (IOM) is a fundamental stabilizer during forearm rotation. To investigate the dynamic aspects of forearm stability, we analyzed sensory nerve endings in the IOM. The distal oblique bundle (DOB), the distal accessory band (DAB), the central band (CB), the proximal accessory band (PAB), the dorsal oblique accessory cord (DOAC) and the proximal oblique cord (POC) were dissected from 11 human cadaver forearms.

Wrist kinetics after scaphoidectomy.

Background: The scaphoid cannot be excised without generating substantial carpal dysfunction. The extent and nature of such a destabilizing procedure, however, has never been properly studied in the laboratory.

Methods: We used a six-degrees-of-freedom motion tracking device to quantify the changes in carpal alignment produced by isometric simultaneous loading of five wrist motor tendons in 12 fresh normal cadaver arms, before and after excising the entire scaphoid.

Anteromedial Release for Posttraumatic Flexion-pronation Contracture of the Wrist: Surgical Technique.

Wrist stiffness can be a complication of trauma. A small percentage of patients fail to improve with nonoperative management and require operative intervention to regain range of motion and function. These group of patients can present with a soft tissue flexion-pronation contracture, which is hypothesized to be caused by capsular contraction of the distal radioulna joint, musculotendinous contracture of the flexor carpi ulnaris, contracture of the volar ulnar carpal ligaments and of the pronator quadratus muscle.

The Twist X-Ray: A Novel Test for Dynamic Scapholunate Instability.

 Scapholunate instability (SLI) is the most common form of carpal instability. Early detection of SLI is imperative as early reconstructive procedures can potentially prevent the natural history of progressive degenerative arthritis. After wrist arthroscopy, magnetic resonance imaging (MRI) remains the next best noninvasive diagnostic option; however, access still remains costly and is often limited in many health care systems worldwide.

Divergent Axial Carpal Dislocation and Its Pathomechanics.

 Axial carpal dislocations and fracture dislocations are 1.4 to 2.08% of all the fractures and dislocations of the wrist.

Biomechanical Analysis of Palmar Midcarpal Instability and Treatment by Partial Wrist Arthrodesis.

Purpose: To create a biomechanical model of palmar midcarpal instability by selective ligament sectioning and to analyze treatment by simulated partial wrist arthrodesis.

Methods: Nine fresh-frozen cadaver arms were moved through 3 servohydraulic actuated motions and 2 passive wrist mobilizations. The dorsal radiocarpal, triquetrohamate, scaphocapitate, and scaphotrapeziotrapezoid ligaments were sectioned to replicate palmar midcarpal instability.

Length Changes in Scapholunate Interosseous Ligament With Resisted Wrist Radial and Ulnar Inclination.

Purpose: To investigate the changes in length of the scapholunate interosseous ligament (SLIL) when the wrist is resisting horizontal lateral load and the forearm is in full pronation in vivo.

Methods: We obtained computed tomography scans of the wrists of 6 volunteers in 3 situations: 0° position (0° extension and 0° ulnar inclination) and full forearm pronation without force, and in the same position but with resisted ulnar and radial deviation. Nine zones of 3 subregions of the SLIL were measured and analyzed with computer modeling.

Resurfacing Capitate Pyrocarbon Implant versus Proximal Row Carpectomy Alone: A Comparative Study to Evaluate the Role of Capitate Prosthetic Resurfacing in Advanced Carpal Collapse.

Background: The Resurfacing Capitate Pyrocarbon Implant associated with proximal row carpectomy has been used to treat symptomatic advanced carpal collapse, widening the indications of proximal row carpectomy to patients with capitate head arthritis. The authors retrospectively compared their case series of implant versus carpectomy alone, analyzing whether prosthetic implant outcomes could be similar to those of proximal row carpectomy even with a higher stage of osteoarthritis.

Methods: Fifty-seven patients who underwent surgery for wrist osteoarthritis (minimum follow-up, 2 years) were selected retrospectively.

Carpal Realignment Using a Strip of Extensor Carpi Radialis Longus Tendon.

Scapholunate instability can lead to posttraumatic dysfunction of the wrist. If unrecognized, it commonly leads to degenerative osteoarthritis. Numerous reparative techniques have been proposed with mixed long-term success.

Carpal Ligaments: A Functional Classification.

Recent laboratory research has disclosed that carpal ligaments exhibit different kinetic behaviors depending on the direction and point of application of the forces being applied to the wrist. The so-called helical antipronation ligaments are mostly active when the wrist is axially loaded, whereas the helical antisupination ligaments constrain supination torques to the distal row. This novel way of interpreting the function of the carpal ligaments may help in developing better strategies to treat carpal instabilities.