Biomechanical study of the abductor pollicis longus & extensor pollicis brevis after release and reconstruction of the first dorsal compartment of the wrist

Amit Gupta,Fateme Mirzaee,Amir Farahanchi Baradaran,Mohammad Amin Aslani,Hamidreza Aslani

doi:10.1016/j.amsu.2021.102863

Abstract

BackgroundThe purpose of this study was to determine the biomechanical changes after first dorsal compartment release and after Z-plasty of the first dorsal compartment with respect to the excursion and displacement of the abductor pollicis longus and extensor pollicis brevis tendons. Materials and methodsSix fresh frozen cadaveric hand and forearms were obtained and the tendons of the abductor were exposed and separated from surrounding tissues through a palmar incision and tenotomized at the musculotendinous junction. The excursion and displacement of the abductor pollicis brevis and flexor pollicis brevis tendons were measured for all six cadaveric hands. ResultsIncreases in tendon excursion were observed in both the abductor pollicis longus (29%) and extensor pollicis brevis (30%) while these observations after Z-plasty were 0.04% for abductor pollicis longus and 0.07% for extensor pollicis brevis. With the use of the modified Elftman curve for the Lengths, tension relationship and Brand's data for resting fiber length we found that 1 cm increase of The excursion of the APL and EPB will decrease tension %65 and %80 respectively. There was also a 12.2-mm displacement of the tendons after release and 4.8 mm displacement after z-plasty of the compartment. ConclusionIt seems that Procedures such as enlargement plasty of Kapandji or Z-plasty will increase the size of the compartment but will not change the biomechanical behaviors of the tendons significantly.

Highlights

The first extensor wrist compartment lies over the radius styloid process and encompasses the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons [1]
In comparison with various degrees of wrist flexion and extension, the most excursion of APL tendon was detected in neutral position (Fig. 2) and the most excursion of EPB tendon after release occurred at 0◦ and 30◦dorsal flexion (Fig. 4)
Even though volar tendon subluxation is often asymptomatic, Volar subluxation of the tendon can lead to chronic tenosynovitis specially when the hand is used for heavy activities have need of wrist flexion and pinch [11,20,21]

Summary

Introduction

The first extensor wrist compartment lies over the radius styloid process and encompasses the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons [1]. By considering his topathologic investigations, de Quervain’s disease is the consequence of tendon sheath thickening due to the myxoid degeneration by mucopolysaccharide accumulation [5] and inflammation does not play a significant role in its occurrence. Most surgeons believe that abnormal compartmanization can lead to the process and maybe explain the undesired results of nonoperative man agement in certain patient populations [2,7,8]. The purpose of this study was to determine the biomechanical changes after first dorsal compart ment release and after Z-plasty of the first dorsal compartment with respect to the excursion and displacement of the abductor pollicis longus and extensor pollicis brevis tendons. Conclusion: It seems that Procedures such as enlargement plasty of Kapandji or Z-plasty will increase the size of the compartment but will not change the biomechanical behaviors of the tendons significantly

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Conclusion