Cost-effectiveness and cost-utility of the ball-and-socket trapeziometacarpal prosthesis compared to trapeziectomy and ligament reconstruction: study protocol for a randomized controlled clinical trial.

BACKGROUND: Trapeziometacarpal (TMC) osteoarthritis (OA) is a common cause of pain and weakness during thumb pinch leading to disability. There is no consensus about the best surgical treatment in unresponsive cases. The treatment is associated with costs and the recovery may take up to 1 year after surgery depending on the procedure. No randomized controlled trials have been conducted comparing ball and socket TMC prosthesis to trapeziectomy with ligament reconstruction. METHODS: A randomized, blinded, parallel-group superiority clinical trial comparing trapeziectomy with abductor pollicis longus (APL) arthroplasty and prosthetic replacement with Maïa® prosthesis. Patients, 18 years old and older, with a clinical diagnosis of unilateral or bilateral TMC OA who fulfill the trial's eligibility criteria will be invited to participate. The diagnosis will be made by experienced hand surgeons based on symptoms, clinical history, physical examination, and complementary imaging tests. A total of 106 patients who provide informed consent will be randomly assigned to treatment with APL arthroplasty and prosthetic replacement with Maïa® prosthesis. The participants will complete different questionnaires including EuroQuol 5D-5L (EQ-5D-5L), the Quick DASH, and the Patient Rated Wrist Evaluation (PRWE) at baseline, at 6 weeks, and 3, 6, 12, 24, 36, 48, and 60 months after surgical treatment. The participants will undergo physical examination, range of motion assessment, and strength measure every appointment. The trial's primary outcome variable is the change in the visual analog scale (VAS) from baseline to 12 months. A long-term follow-up analysis will be performed every year for 5 years to assess chronic changes and prosthesis survival rate. The costs will be calculated from the provider's and society perspective using direct and indirect medical costs. DISCUSSION: This is the first randomized study that investigates the effectiveness and cost-utility of trapeziectomy and ligament reconstruction arthroplasty and Maïa prosthesis. We expect the findings from this trial to lead to new insights into the surgical approach to TMC OA. TRIAL REGISTRATION: ClinicalTrials.gov NCT04562753. Registered on June 15, 2020.

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. METHODS: The study involved a comprehensive review of neuromuscular mechanisms in dynamic stabilization of the carpus, based on cadaver studies. The 3D position of the scaphoid, triquetrum, and capitate was monitored before and after tendon loading. RESULTS: The extensor carpi ulnaris (ECU) and the flexor carpi radialis (FCR) are identified as the primary pronators of the midcarpal joint. The ECU's pronation effect can potentially strain the scapholunate ligament, while the supinator muscles, the abductor pollicis longus (APL), the extensor carpi radialis longus (ECRL), and the flexor carpi ulnaris (FCU), have a protective role, particularly in cases of scapholunate ligament dysfunctions. The FCR, despite being a pronator of the distal row, has a beneficial effect as it provokes supination of the scaphoid. CONCLUSIONS: Comprehending carpal dysfunctions and instabilities hinges on understanding carpal anatomy and normal biomechanics. Proprioception, encompassing joint position sensation and neuromuscular control, is pivotal for stability. Biomechanical research informs tailored muscle strengthening for specific carpal issues. Supinator muscles should be strengthened for SL injuries, and ECU-focused strengthening and proprioceptive training are key for dynamic LTq instabilities. Ongoing research should delve into the intricate relationship between carpal ligaments, muscles, and proprioception to enhance wrist stability.

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. We emphasize the significance of forearm rotation to enhance treatment efficacy. STUDY DESIGN: We conducted an experimental study to understand how forearm muscles contribute to the stability of the scapholunate joint during different degrees of forearm rotation and we focused on the joint effect of muscle groups rather than individual muscles for treatment protocols. RESULTS: Our findings shed light on the conservative treatment of dynamic scapholunate instability and the postoperative rehabilitation of scapholunate ligament repair. We found that the effect of forearm muscles significantly contributes to preserve stability in the scapholunate joint across various forearm rotational positions. These insights have practical implications for hand therapists, offering innovative strategies to enhance clinical practice. CONCLUSIONS: This research underscores the importance of considering forearm rotation when developing rehabilitation protocols for scapholunate joint instability and provides a valuable perspective in line with current rehabilitation principles.

Kienböck's disease: preventing disease progression in early-stage disease.

Currently Kienböck's disease remains an 'unsolved' problem in hand surgery. Different factors have been associated with the avascular necrosis of the lunate. Mechanical, vascular and biological factors, alone or in combination, may have an influence in the aetiopathogenesis and determine the progress of the disease and even the results of the treatment. This is especially relevant in the early stages, in which conservative or surgical treatment may modify the natural history of the disease, maintaining the lunate structure and thus preserving the joint surfaces. There are multiple surgical treatments for Kienböck's disease in the early stages, before lunate collapse; each one is based on one of the possible factors that can cause avascular necrosis of the lunate. The objective is not only to treat symptoms but to prevent progression. This article is a review of the most frequent treatments used in the early stages and a personal view of the authors.Level of evidence: V.

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. Clinical data from 12 patients were collected retrospectively and used to analyze the patients' symptomatic and asymptomatic (contralateral) wrists with a newly developed test called the Bilateral Ulnar Deviation Supination (BUDS) test. A wrist arthroscopy was performed in all cases as a reference standard for the radiologic test. RESULTS: The test was positive in 7 patients, with a mean scapholunate joint gap of 4.8 mm. The mean differences in the scapholunate joint gaps between both wrists were 2.6 mm in BUDS-positive patients and 0.2 mm in BUDS-negative patients. A Geissler stage III or IV scapholunate ligament rupture was confirmed in all BUDS-positive patients; by contrast, BUDS-negative patients exhibited either no lesion or a Geissler stage I injury. CONCLUSIONS: The BUDS test is a new radiologic test based on proven biomechanical effects that is able to accurately assess dynamic scapholunate dysfunctions. The analysis carried out found a correlation between radiographic and arthroscopic findings. Further research is needed to confirm the validity and reliability of the test. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

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. The goal of this research was to evaluate the biomechanical behavior of scapholunate advanced collapse wrists compared to an experimental group with simulated injuries. METHODS: Using a magnetic 6-degree of freedom motion tracking device, changes in scaphoid alignment induced by isometric loading 5 wrist motor tendons in two groups of specimens were monitored. Twelve fresh cadaver wrists in which scapholunate injury was simulated by sectioning the scapholunate ligament were compared to 5 arms with chronic scapholunate dissociation. FINDINGS: The behavior of the scaphoid is the same in both groups, but the magnitude of displacement is greater in chronic scapholunate dissociation wrists, although not statistically significant. The extensor carpi ulnaris is the only muscle that provokes scaphoid pronation; all other muscles induce its supination. INTERPRETATION: Different factors may play a role in the amount of scaphoid rotation observed in wrists with chronic scapholunate dissociation. Ligament sectioning alone in the experimental setup can only partially replicate the behavior of real scapholunate dissociations. The extensor carpi ulnaris has a major role in destabilizing scapholunate advanced collapse wrists; therefore, isometric contraction of this muscle should be avoided in the conservative treatment. The experimental setup designed is useful to evaluate the biomechanical behavior of the carpus under traction load.

Cold Welding in a Trapeziometacarpal Ball and Socket Prosthesis: A Case Report.

While in revision hip surgery it has been described cold welding of the femoral component in titanium implants, no previous reports have been published in TMC prosthesis. We present a case report of a patient who sustained a TMC ARPE® dislocation 11 months after surgery and during revision surgery, cold welding of the neck with the metacarpal stem was observed. This may represent a problem when revising this prosthesis and alternative procedures should be advised and discussed with the patient when revising these implants.

Osteoid osteoma of the hamate presenting as a midcarpal synovitis.

Background Osteoid osteoma is a benign bone lesion of unknown etiology uncommonly affecting the carpal bones. In the upper extremity, the clinical and imaging picture may be misleading, often mimicking other entities. We present a rare case of a patient with a subchondral osteoid osteoma mimicking a posttraumatic midcarpal synovitis. Case Description A 21-year-old woman presented with persistent pain and swelling of the right wrist. Physical examination revealed swelling and pain on direct palpation over the dorsal aspect of the wrist. Radiographs were normal. Inconclusive computed tomography (CT) and magnetic resonance imaging (MRI) scans suggesting an occult fracture versus avascular necrosis delayed the diagnosis. Scintigraphy and fine-cut CT scan provided the definitive diagnosis. Surgical excision of the nidus and synovectomy of the midcarpal joint were performed, with complete resolution of pain and rapid return to normal function. Literature Review Three different types of osteoid osteoma have been described according to radiological methods: cortical, medullar, and subperiosteal. When localized in the carpus, most lesions are intra-articular. Reactive synovitis is often present and may be the primary symptom. Radiofrequency ablation is a treatment alternative. However, if a safe distance between the electrode and a major neurovascular structures (up to 1.5 cm) cannot be guaranteed, surgical excision is recommended. Clinical Relevance A high index of suspicion and careful attention to the clinical picture are necessary for accurate diagnosis and treatment of osteoid osteoma in the hand and carpus. CT scan and scintigraphy are the most sensitive complementary investigations and enable definitive diagnosis and treatment.

Role of the extensor carpi ulnaris in the stabilization of the lunotriquetral joint. An experimental study.

STUDY DESIGN: Experimental laboratory-based research in biomechanics. INTRODUCTION: The mechanisms by which some lunotriquetral (LTq) ligament disruptions remain stable are not known. PURPOSE OF THE STUDY: To investigate the contribution of muscles in preventing carpal destabilization when the LTq ligaments are torn. METHODS: Ten fresh cadaver wrists, set vertical in a jig, were isometrically loaded through five wrist motor tendons. Changes in carpal alignment secondary to the application of loads were monitored by a Fastrak™ electromagnetic motion tracking device, before and after sectioning the LTq ligaments. RESULTS: After LTq ligaments sectioning, wrist loading forced the triquetrum into flexion (5.4° average) and supination (2.9 ). The only muscle capable of extending and pronating the collapsed triquetrum was the extensor carpi ulnaris (ECU). CONCLUSIONS: Inadequate ECU muscle function is an important destabilizing factor in LTq deficient wrists. Dynamic LTq instabilities may benefit from proprioceptionally training the ECU muscle, while avoiding carpal supination torques.

Scapholunate instability: proprioception and neuromuscular control.

From a kinetic point of view, the wrist is considered stable when it is capable of resisting load without suffering injury. Several prerequisites are necessary for the wrist to be kinetically stable: bone morphology, normal articulating surfaces, ligaments, the sensorimotor system, the muscles crossing the wrist, and all nerves connecting to ligaments and muscles. Failure of any one of these factors may result in carpal instability. The terms "scapholunate (SL) dissociation" and "SL instability" refer to one of the most frequent types of wrist instability, resulting from rupture or attenuation of the SL supporting ligaments. From a radiologic point of view, SL instability may be dynamic or static. Unlike static instabilities, which tend to be painful and dysfunctional, a good proportion of dynamic SL instabilities remain asymptomatic and stable for prolonged periods of time. Such a lack of symptoms suggests that a ligament rupture, in itself, is not enough for a joint to become unstable. Certainly, the process of achieving stability is multifactorial and involves normal joint surfaces, ligaments, muscles, and a complex network of neural connections linking all these elements. In this article, we will review the neuromuscular stabilization of the SL joint and the proprioceptive mechanisms that contribute to the dynamic carpal stabilization.