Carpal Ligaments: A Functional Classification

Partial Scapholunate Interosseous Ligament Injuries: A Systematic Review of Treatment Options

Purpose  This systematic review summarizes the existing evidence on treatment options and outcomes for partial scapholunate interosseous ligament (pSLIL) injuries. Methods  A systematic electronic search of Medline, Embase, and CINAHL was performed from inception through to February 13, 2022. All primary research articles addressing the treatment of pSLIL tears were eligible for inclusion regardless of timing of surgery, surgical technique, or rehabilitation. The PRISMA Checklist guided the reporting and data abstraction. Descriptive statistics and forest plots are presented. Results  A total of 14 studies with 342 patients were included for analysis. Treatments were categorized into four groups: electrothermal shrinkage (ES), arthroscopic capsuloplasty (AC), open capsulodesis (OC), and no treatment (NT). There were five studies in the ES group ( N  = 69, mean age = 34.3 ± 3.3 years), three studies in the AC group ( N  = 138, mean age = 32.2 ± 3.8 years), five studies in the OC group ( N  = 123, mean age of 30.7 ± 7.8 years), and one study in the NT group ( N  = 12, mean age = 43 years, range = 28-67 years). The average postintervention visual analog scale pain score for the ES group was 1.4 ± 0.5 (from 5.7 ± 1.8), for the AC group was 3.2 ± 1.3 (from 6.6 ± 0), for the OC group was 2.3 ± 2.1 (from 5.6 ± 1.6), and for the NT group was 3.2 (from 7.6). The wrist extension range of motion improved postoperatively for all intervention groups (ES = 66.3°-70.7°; AC = 67°-74.5°; and OC = 48.9°-63.5°), whereas it remained unchanged for the NT group (46°-45°). Grip strength also improved in all intervention groups (ES = 17.9-29.9 kg; AC = 24.0-32.2 kg; and OC = 15.8-26.6 kg), while the NT group remained unchanged (25-24 kg). The radiographic scapholunate gap improved postoperatively in all groups that reported pre- and postintervention (ES = 2.2-1.9 mm; OC = 2.5-1.8 mm) and slightly worsened in the NT group (2.5-2.7 mm). In the ES group, there were three complications (11.5%, no major complications), in the AC group there was one major complication (0.9%, complex regional pain syndrome [CRPS]), and in the OC group there were six complications (15.4%, four major complications-CRPS). Conclusion  All interventional treatment options (ES, AC, and OC) provided significant improvements in patient-reported pain, range of motion, grip strength, and radiographic parameters, with low complication rates. In comparison, no improvement in range of motion or grip strength was noted in the NT group. Therefore, surgical management of pSLIL injuries is an effective and relatively safe treatment option. Further studies comparing the outcomes of specific surgical treatments are warranted to further elucidate the optimal management option for pSLIL tears. Level of Evidence  Level III, systematic review of Level III-IV studies.

[Osteoarthritis of the wrist]

The term osteoarthritis (OA) of the wrist can be used as an umbrella term for various, often independent areas of OA, as the wrist is made up of several joints. Radiocarpal OA often occurs after untreated ligament injuries, incorrectly healed bone fractures in the carpus or after radius fractures involving the joint. A typical sequence of propagation is known for radiocarpal OA following scapholunate (SL) insufficiency or scaphoid pseudarthrosis. Other causes include inflammation, crystal deposits or bone necrosis. Ulnocarpal arthrosis occurs posttraumatically or primarily when there are differences in levels between the ulna and radius. When treating wrist arthrosis, after conservative measures have been exhausted a surgical procedure should be chosen that enables the best possible load-bearing and residual mobility, considering the surgical risks and individual requirements. During salvage operations, the defective cartilage areas are either fused directly or eliminated using appropriate diverting partial fusions and resection arthroplasty. An accurate analysis of the affected zones is crucial for selecting an appropriate intervention.

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.

Tratamiento de lesiones escafolunares mediante reconstrucción con plastia del extensor radial largo del carpo

Objetivo Describir la técnica quirúrgica de reconstrucción del ligamento escafolunar asistida por artroscopia empleando como donante el extensor carpi radialis longus (ECRL), un músculo que, gracias a sus propiedades biomecánicas, puede ser muy ventajoso en este tipo de cirugía.

Técnica Quirúrgica Tras artroscopia diagnóstica inicial según la técnica habitual, se llevó a cabo la reconstrucción ligamentosa empleando un hemitendón del ECRL mediante técnica mínimamente invasiva. Los dispositivos de fijación empleados fueron el SwiveLock para el escafoides y el tornillo de biotenodesis de 3 × 8 mm (Arthrex, Naples, FL, EE.UU.) para el semilunar.

Complicaciones La complicación que puede surgir durante la realización de esta técnica es la extracción dificultosa de la plastia, por la intersección entre el primer y el segundo compartimentos extensores. Es fácilmente solventable realizando una incisión intermedia a nivel de la intersección para garantizar la adecuada liberación de la plastia a esta altura.

Conclusión Es posible reconstruir el intervalo escafolunar empleando un hemitendón del ECRL, que, por propiedades biomecánicas, puede ser más ventajoso a la hora de restaurar la biomecánica del carpo. Se precisan estudios posteriores para confirmar la idoneidad y la superioridad de este donante frente a otros empleados en las técnicas de reconstrucción.

Arthroscopic Management of Intra-articular Ligament Lesions on Distal Radius Fractures

Articular distal radius fractures (DRFs) have increased in incidence in recent years, especially among the economically active population. Most of the treatment approaches are based on plain X- rays, and do not give us any information on how to treat these fractures. In the search for solutions with greater precision in diagnosis, in reducing the joint surface of the fracture, and envolving minimally-invasive techniques, we found arthroscopy as the main tool for these patients. Therefore, an enhanced understanding of the biomechanics of the different types of fracture associated with ligamentous lesions should facilitate the right decision regarding the treatment. The present paper aims at providing a management-oriented concept to diagnose and treat ligamentous lesions associated with intra-articular DRFs based on a arthroscopy-assisted procedure, and showing the objective and patient-reported outcomes and a new classification. The objective and patient-reported outcomes were: the mean range of motion (ROM) was of 94.80% on the non-affected side; the mean score on the abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) was of 3.6 (range: 1 to 12). The score on the Visual Analog Scale (VAS) was of 1.66 (range: 1 to 3). Complications were observed in 2 (13.33%) patients: extensor tendon synovitis in 1 patient, and a limitation (stiffness) in ROM in 1 patient, both treated with wrist arthroscopy release. The mean time until the return to work was of 6.4 weeks. In patients with unstable intra-articular DRFs associated with ligamentous lesions, the fixation of specific osseous-ligamentous fragments and ligamentous repair/reconstruction by wrist arthroscopy prove to be a safe and reliable treatment. The clinical and functional results predict that the patients can return to work more quickly.

A Biomechanical Evaluation of the ECRL Tenodesis for Reconstruction of the Scapholunate Ligament

PURPOSE

Reconstruction of the scapholunate ligament (SLL) in the setting of dynamic instability remains a surgical challenge, with lack of consensus on the best reconstructive procedure. Reconstruction of only the dorsal component may lead to volar gapping and abnormal wrist kinematics. This cadaveric active motion simulation study determined whether scapholunate (SL) motion, angulation, and contact are restored following open reconstruction using the extensor carpi radialis longus (ECRL) tenodesis, which reconstructs both the volar and the dorsal SLL components.

METHODS

Seven fresh-frozen cadaveric upper limbs (mean age, 68 ± 10.1 years) underwent a 4-stage protocol of cyclic dart-throw motion and flexion-extension motion (utilizing an active wrist motion simulator that used tendon load/motion-controlled actuation. Scaphoid and lunate motion, relative scaphoid translation, SL angle, and dorsal-volar SL diastasis were measured with (1) wrist ligaments intact, (2) following complete sectioning of the SLL, and (3) following SL reconstruction using the ECRL tenodesis technique.

RESULTS

Complete SLL sectioning resulted in a typical pattern of SL instability. Following the ECRL tenodesis, lunate extension was not corrected. Scaphoid flexion, however, was not significantly different from the native state in FEM but remained significantly flexed during dart-throw motion. Differential dorsal and volar gapping did not significantly improve following ECRL tenodesis (dorsal, 1.2-2.3 mm; volar, 1.1-1.7 mm).

CONCLUSIONS

This biomechanical study demonstrates that the ECRL tenodesis did not fully restore native carpal kinematics, despite dorsal and volar SLL, and scaphotrapeziotrapezoid reconstruction.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.