El papel de la propiocepción y el control neuromuscular en las inestabilidades del carpo

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.

Exercise-based intervention as a nonsurgical treatment for patients with carpal instability: A case series

BACKGROUND

Although the important roles of proprioception and neuromuscular control in carpal instabilities under laboratory conditions have been recognized, only a few studies have translated this knowledge into a routine clinical practice.

PURPOSE

This study aimed to evaluate the results of a personalized rehabilitation in patients with carpal instability on functionality and pain intensity.

STUDY DESIGN

This was a case series study.

METHODS

This case series included 39 adults (mean age: 38.2 ± 14.0 years; 16/23 females/males) diagnosed with carpal instability (radial or ulnar) with indication for orthopedic treatment. The disabilities of the arm, shoulder, and hand questionnaire was used to assess upper limb functionality. Pain perception was assessed using a visual analog scale. Exercise-based physiotherapy interventions were performed according to the clinical needs of the patients for at least 6 weeks (2-3 sessions per week). For the treatment of radial instability (n = 13), strengthening exercises of the abductor pollicis longus, extensor carpi radialis longus, flexor carpi radialis, and pronator quadratus muscles were prescribed. For the treatment of ulnar instability (n = 24), extensor carpi ulnaris and pronator quadratus were trained. All patients underwent proprioceptive training in open kinetic chain and closed kinetic chain, as well as strengthening of the unaffected hand. Changes before and after treatment were compared using the nonparametric Wilcoxon signed rank test.

RESULTS

A significant improvement with a large effect size in disabilities of the arm, shoulder, and hand (P < .001; d = 2.9) and visual analog scale (P < .001; d = 3.2) scores were obtained after treatment. Moreover, the changes were greater than the minimal clinically important difference of 10.8 and 1.4, respectively. Similar results were found when patients with radial instability and ulnar instability were analyzed separately.

CONCLUSIONS

Personalized training with specific proprioception and strengthening exercises produces improvements in functionality and pain perception in our cohort of people with carpal instability. These results highlight the importance of multicomponent exercise in the treatment of wrist instability. Future randomized clinical trials should further investigate the effectiveness of this protocol.

Four-Corner Fusion with Locking Dorsal Circular Plate versus Headless Compression Screws: A Clinico-Radiological Comparative Study

Introduction Four-corner fusion is a technique for the treatment of carpal advanced collapse. It consists of scaphoid excision and arthrodesis of the lunate, triquetrum, hamate, and capitate bones. This can be accomplished with different kinds of osteosynthesis. In the first reports of the use of a circular plate, poor outcomes are described, with high rates of non-union, which decreased in later studies, which highlight certain aspects of the surgical technique.

Objective To report our experience with four-corner fusion with the use of a dorsal locking plate (Xpode, Trimed Inc., Santa Clarita, CA, US), and compare it with another traditional fixation method (3.0-mm headless compression screws [HCSs], Synthes, Slothurn, Switzerland), with an emphasis on union, an assessment of the fincitonal outcomes, and the presence of complications.

Material and Methods A comparative study of two prospective series of patients operated on through two fixation techniques for four-corner fusion using autologous bone graft from the iliac crest.

The first group of patients, evaluated between 2010 and 2012, underwent osteosynthesis with 2 HCSs, with a minimum follow up of 18 months. The second group, evaluated between 2011 and 2014, underwent osteosynthesis with a dorsal locking plate, with a minimium foloow up of 12 months. The patients were operated on by four different surgeons in four centers.

The patients were evaluated with radiographs to establish the presence of union and the time it took to occur. In case of doubt, union was confirmed through a computed tomography (CT) scan at 8 weeks postoperatrively. We also assessed the range of motion, the presence of complications, and function through the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and a grip strength score.

Results We achieved a union rate of 100% in both groups at similar times. In the dorsal locking plate group, we obtained better full range of motion, particularly in wrist extension, which was statistically significant (p = 0.0016), as well as lower DASH scores, which was also statistically significant (p = 0.0066). Complications were only present in two patients in the HCS group.

Conclusion Both techniques are valid and reproducible for the treatment of wrists with scapholunate advanced collapse (SNAC) and scaphoid non-union advanced collapse (SLAC). Based on the outcomes, with the Xpode plate, the patients presented better ranges of motion and DASH scores; therefore it may be an excellent fixation option in the open four-corner fusion surgical technique. The entry point and configuration of the HCS are fundamental variables to analyze.

The union rate of 100% obtained in the present study contrasts with the high rates of non-union reported in the literature published in the early 2000s.

El papel de la rehabilitación tras las reparaciones de las inestabilidades de muñeca

De las patologías de muñeca más frecuentes en la consulta del cirujano de la mano, las inestabilidades carpianas ocupan un lugar importante junto con el dolor en la vertiente ulnocarpiana cuya causa más frecuente son las lesiones del complejo fibrocartílago triangular, que en ocasiones van a condicionar una inestabilidad de la articulación radiocubital distal. Analizando los datos anatómicos y biomecánicos que diponemos de la muñeca y tomando como punto de partida los escasos protocolos rehabilitadores de las inestabilidades escafolunares y lunopiramidales que existen en la bibliografía, se exponen los programas rehabilitadores específicos para cada una de ellas. Se describen también los protocolos existentes para la rehabilitación tras las reparaciones del complejo fibrocartílago triangular y exponemos los protocolos con los que trabajamos en la actualidad.

Definimos también la importancia de la reeducación propioceptiva en este tipo de lesiones y describimos un programa detallado de introducción progresiva de determinados ejercicios encaminados a ello.

Arthroscopic reconstruction for unstable scaphoid non-union

OBJECTIVE

To evaluate the results of arthroscopic reconstruction for the treatment of unstable scaphoid non-union with cancellous bone autograft.

METHODS

13 patients were treated with a mean age of 26 (18-45) years. The average time from injury until surgery was 14 (6-48) months. Preoperative and postoperative clinical and radiological parameters were evaluated. Mean follow-up was 16.8 (12-36) months.

RESULTS

Consolidation was achieved in all cases at 7 (4-10 weeks), no patient had complications or reoperations. Range of motion, pain, functional assessment (DASH questionnaire) and radiological measurements improved compared to preoperative measurements. The average range of flexion improved: flexion 71.9° (55°-80°) to 81.7° (55°-90°), extension 66.3° (30°-80°) to 84.4° (70° -90°), ulnar deviation 21.5 (10°-25°) to 25.5° (20°-45°) and radial deviation 11.9° (5°-25°) to 13.3° (10th-20th). Pain (VAS 0-10) improved from 6.8 (4-10) to 0.7 (0-3). DASH functional scale improved from 36 (12-78) to 8 (0-10). The Scapho-Lunate Angle improved from 67.7° (62°-88°) to 47° (32°-55°), and the Radio-Lunate Angle improved from 30.8° (10° -45°) to 4(0°-10°).

CONCLUSION

Treatment of unstable scaphoid non-union with cancellous bone graft assisted by arthroscopy presents good clinical results with a short period of consolidation and recovery.