New Functional Evaluation Scheme - Modality of the Results of Forearm Tendon Transfers Evaluation in Cases of Irreparable Radial Nerve Injury

Abstract

Introduction: There are several evaluation schemes for the results of tendon transfers in case of radial nerve paralysis, and the most logical and commonly used are evaluation schemes that use the range of active joint movements to evaluate the results. Aim: Present an original evaluation scheme for tendon transfer results based on functional wrist and fingers joint movements. The aim of the article is to present the advantages of our own Functional scheme in comparison with other schemes, its simplicity and applicability in the evaluation of all clinical cases of different postoperative outcome of the variables being evaluated, and to present the ease of comparison of the achieved results with other authors who would possibly use our scheme because it minimizes the subjective error of the examiner. The secondary aim is to compare the results of flexor carpi radialis (FCR) vs. flexor carpi ulnaris (FCU) tendon transfers (TT). Methods: The study was conducted as clinical and retrospective. The study included 60 patients with isolated radial nerve palsy operated by two tendon transfer surgical methods (FCR and FCU) over a 10-year period. The evaluation of the results was performed by using Zachary, Neimann-Pertecke, Tajima evaluation schemes, our own Functional Evaluation Scheme as well as subjective patient evaluation. Results: The time elapsed from injury to surgery ranged from 105 to 956 days in case of FCR tendon transfer and from 109 to 712 days in cases of FCU tendon transfer. The overall average age of patients is 36.71 years. A statistically significant difference in values with t-test based on the Functional Evaluation Scheme was found in the variables of ulnar deviation (p=0.000731), extension of the MP fingers joints II-V (p=0.04610) and extension of the MP of the thumb joint (p=0.0475). Evaluation of the total results with t-test (p=0.007532) and with U-test (p=0,00433) showed statistically better FCR tendon transfer results. A statistically significant difference in value measured by the t-test was found in the evaluation of the overall results (p=0.022) with Zachary and Neumann-Pertecke schemes and by the Tajima evaluation Scheme (p=0.042) in favor of better FCR tendon transfer results. With a use of Functional Evaluation Scheme, it is possible to evaluate all the results unlike most available schemes. Conclusion: The functional evaluation scheme is based on the functional joint movements evaluated and incorporating radial and ulnar deviation of the wrist (RD and UD), extension of the metacarpophalangeal (MCP) joint and flexion of the intephalangeal (IP)joint of the thumb in the final evaluation becomes completely original. A functional evaluation scheme is simply applicable for the evaluation of all clinical cases of different postoperative outcome of the variables being evaluated. FCR tendon transfer achieves better results than FCU TT.

Results of Tendon Transfers in Radial Nerve Palsies: A New Evaluation Protocol

“…The most common clinical presentation of radial nerve palsies is characterized by denervation of the extensor musculature with the characteristic 'Wrist-Drop Sign' [17]. In complete paralysis, extension is maintained at the level of the interphalangeal joints, as it affects the intrinsic musculature innervated by the ulnar nerve.…”

“…In these cases it may be necessary to perform a tendon transfer later to restore the lost function [20]. The main indication for upper extremity tendon transfer is a peripheral nerve injury with no potential improvement [17,21].…”

“…However, literature reports only a few studies that analyze the results with evaluating score systems. The standardization of results in tendon transfers is not straightforward [17,26].…”

“…In a recent work, Karabeg et al [17] develop a new evaluation system that, like ours, aims at standardization and repeatability of the system. With the present study, we have completed and supplemented the attempt to standardize the assessment of results in palliative radial nerve palsy surgery by introducing new factors, such as the flute test, which aims at assessing the recovery, albeit partial, of finger independence, as well as the strength recovered and the subjective component of patients' satisfaction.…”