Does anterior plus posterior interosseus neurectomy lead to better outcomes than isolated posterior interosseus denervation in the treatment of chronic wrist pain? A systematic review of the literature and meta-analysis

Introduction

Wrist arthritis, either primary or secondary, is a debilitating condition that often leads to significant limitations in the use of the hand due to chronic wrist pain. When conservative treatment fails, surgical intervention is often required, including proximal row carpectomy, total or partial wrist arthrodesis, or other procedures (1).

Partial and total wrist denervations are performed as salvage procedures and can significantly decrease the pain, while maintaining range of motion (ROM) and grip strength, with more predictable results than arthrodesis. In fact, loss of motion and grip strength can be more debilitating for active individuals than the wrist pain itself (2).

The literature describing patient-reported outcome measures following wrist denervation procedures is sparse although denervation appears as a viable option to treat chronic wrist pain.

A 2020 systematic review including 21 articles concluded that both partial and total wrist denervations provide good pain relief and preserve wrist movement, but the authors noted within the study's limitations that they categorised all types of partial wrist denervations as a unique procedure, without performing separate assessments of the different partial denervation techniques used (3).

Since Berger's description of the technique of surgical neurectomy of the anterior interosseous nerve (AIN) and posterior interosseous nerve (PIN) using the same dorsal approach, numerous surgeons have reported this procedure as safe and reliable (4).

In 2017, Vanden Berge reviewed 6 studies involving a total of 135 patients treated with isolated PIN neurectomy and reported satisfactory results with few patients experiencing recurrent pain at long-term follow-up (5).

To the best of our knowledge, there are no studies comparing the results of the combined technique described by Berger (AIN plus PIN) vs the isolated PIN neurectomy.

The objective of this review is to compare the outcomes in a large group of patients who have undergone partial denervation of the wrist either by isolated PIN or combined AIN plus (+) PIN neurectomy techniques.

Materials and methods

A comprehensive literature search was performed to identify all publications on isolated PIN or AIN + PIN denervation according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with a PRISMA checklist and algorithm. A literature search was performed combining the following keywords: ‘wrist denervation’, ‘PIN neurectomy’, ‘‘AIN neurectomy’’, ‘anterior interosseous nerve neurectomy’ and ‘posterior interosseous nerve neurectomy’. The search results were updated on the 1st of July 2022 on Medline (PubMed), Web of Science and Scopus. The reference lists of all included articles were screened for further eligible studies that may have been missed during the first electronic search. Only articles written in English were included. Inclusion criteria were peer-reviewed clinical studies of level I–IV evidence involving at least 10 patients with at least 1 year and 80% follow-up, and reporting at least 1 outcome measure of interest including post-operative pain, function or failures. Exclusion criteria were studies written in other languages (not in English), abstracts without a published study, pharmaceutical or non-surgical studies, anatomical studies and presence of additional surgical procedures performed either before, simultaneously to or after denervation. Researchers were contacted if the full text was not available.

Each study included in this review was assessed according to a modified Coleman Methodology Score (CMS) (6) that takes into account not only the study design and methodology but also assesses the quality of outcome reporting. The specific Coleman criteria were modified to make them reproducible and relevant for this systematic review (Table 1). Each study was scored by 2 reviewers independently and in duplicate to give a total CMS between 0 and 100.

The demographic of the sample, surgical procedure, data on clinical outcome, satisfaction, return to work and failures were recorded.

Results

Eight hundred and twenty-nine studies were found initially that were then subjected to further screening (Fig. 1). We first removed the duplicates (218) and another 190 were excluded due to obvious irrelevance to the subject matter. After a further screening of titles and abstracts, a further 238 studies were excluded, being either pharmaceutical or non-surgical studies describing other conditions or studies in other languages. Of the 183 remaining studies, 8 were excluded because there was only an abstract but a full text was not available, being them only published in abstract books. The full texts of the remaining 175 studies were obtained and read, leading to the exclusion of a further 165 studies (anatomical studies, presence of additional procedures, studies not fulfilling the inclusion criteria).

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PRISMA flow chart of our studies selection.

Citation: EFORT Open Reviews 8, 3; 10.1530/EOR-22-0089

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Finally, 10 studies totalling 325 patients (347 wrists, 22 bilateral) were included in this systematic review (4, 7, 8, 9, 10, 11, 12, 13, 14, 15). The publication date of the included studies ranged from 1985 to 2019. The most frequent journal included was the Journal of Hand Surgery (n = 4; 3 from the American Volume and 1 from the European Volume). All sample characteristics described (Table 2) do not include patients lost to follow-up and exclusively report the outcomes of the procedures covered by this review.

Meta-analysis

The report by Sgromolo et al. (12) was excluded from the meta-analysis because it did not report failures as an outcome. The meta-analysis performed based on patients undergoing isolated PIN neurectomy showed a sample heterogeneity I² of 31.0% and a pooled failure rate of 15.1% 95% CI 8.8 to 22.7 (random effects) at a follow-up with a median of 22 months (16–56) (Fig. 2). Also the meta-analysis related to the denervation of AIN + PIN showed a very high heterogeneity of the sample (I² = 62.6%), and at a median follow-up of 29 months (12–81), it showed a pooled failure rate of 23.6% (random effects) with a 95% CI of13.9–34.9 (Fig. 3). The Chi-square test for comparing the two proportions of the aforementioned studies showed a difference bordering on statistical significance: P = 0.0501.

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Forest plot of the meta-analysis performed on isolated posterior interosseus nerve (PIN) neurectomy. Heterogeneity of the sample (inconsistency, I²): 31.03% 95% CI for I² = 0.0–73.54.

Citation: EFORT Open Reviews 8, 3; 10.1530/EOR-22-0089

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Forest plot of the meta-analysis performed on anterior interosseus nerve (AIN) plus posterior interosseus nerve (PIN) denervation. Heterogeneity of the sample (Inconsistency, I²): 62.57% 95% CI for I² = 0.0–87.41.

Citation: EFORT Open Reviews 8, 3; 10.1530/EOR-22-0089

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The combined results of both techniques for partial denervation indicate a general failure rate of 21.6% ;95% CI: 12.4–26.3 (75 wrists out of 334) with a global heterogeneity of the sample I²: 61.64%, 95% CI I² = 20.70–81.45.

Discussion

The main finding of this systematic review is that the techniques for partial denervation of the wrist have shown an overall success of 78.4% with regard to pain relief, without substantial complications. In particular, the isolated PIN denervation consists of a 4–5 cm longitudinal incision over the distal dorsal forearm, just proximal to the distal radioulnar joint. The PIN can be identified after a deep antebrachial fascia splitting, on the floor of the fourth extensor compartment on the ulnar side of the extensor pollicis longus. A 1 cm segmental neurectomy of the PIN is enough to achieve its distal denervation (16). This technique in our review showed 85% success at a median follow-up of 22 months. Ever since Wilhelm popularised total wrist denervation as a treatment option for wrist pain, several modified techniques have been described that have tried to reduce the number of surgical approaches (16, 17), and more recent studies have demonstrated that the primary innervation of the wrist is via the AIN and the PIN (18, 19, 20). Anatomically the AIN is very close to the PIN. According to the technique described by Berger, in fact, through the same approach, after removing a 1 cm segment of the PIN, the interosseous membrane is incised longitudinally. The AIN is located just deep to the interosseous membrane, 1 mm dorsal to the pronator quadratus muscle. The AIN may be accompanied by the anterior interosseous artery and its venae comitantes. The AIN and the vessels must be separated gently and at least 1 cm of the AIN is excised. The combined AIP + PIN neurectomy technique in our experience may increase the surgical time in comparison with the isolated PIN neurectomy, although we are unable to demonstrate the actual procedure time difference because no article has reported on them. Anyway, our review showed that the AIN + PIN neurectomy technique had a 77% success at a follow-up with a median of 29 months. In general, on all 347 wrists reviewed, the improvement in function assessed with clinical evaluation scores such as DASH, MWS, PRWE, the increased grip when an evaluation with the dynamometer was performed and the reduction of pain, demonstrate the achievement of the fundamental principle of partial wrist denervation (4), that is to continue to benefit from hand and wrist function and ROM without pain. The general satisfaction of patients also proved to be high (Table 1), confirming that partial denervation is a viable procedure for the symptomatic arthritic wrist. However, the moderate scientific quality of the reports that fulfilled our inclusion criteria requires a more detailed interpretation of the data and the failures. In fact, although the difference in the success outcomes of both techniques assessed is at the border of statistical significance, as an absolute value, the AIN + PIN denervation technique appeared to show a greater failure rate. However, it should also be noted that the reported follow-up of the latter technique is longer, even reaching 81 months. It has also to be taken into account the fact that denervation is a procedure that relieves pain but does not stop the progression of the disease; therefore, some of the reported additional surgical procedures may have been carried out due to the disease progression itself and not only due to a failure of the denervation technique adopted. In any case, it is obvious that carrying out an additional neurectomy of the AIN is a more invasive procedure than performing an isolated PIN neurectomy, as it is required to incise also the interosseous membrane, with the additional risk of injuring the vessels located next to the AIN. New large prospective, randomised and multicentre controlled trials with homogeneous methodology and protocols are required. These studies should report on accurate outcomes not only regarding pain improvement, patient satisfaction and return to work but also hospitalisation times and post-operative recovery time. In fact, even if the consequence of AIN and PIN denervation on wrist proprioception has been studied, in order to reduce any potential clinical sequelae of denervation, particularly in young and active patients, we should be able to offer the best solution with the lesser invasivity to our patients. In none of the examined studies, the outcomes of isolated PIN vs combined AIN + PIN denervation were compared. Sgromolo et al. reported solely the difference in treatment between the two techniques but described only cumulative combined results without comparing them.

A major limitation of our study was the high heterogeneity of the studies reviewed, which limits the power of our conclusions. In fact, it was not possible to ascertain whether the limited follow-up available leads to underestimating the actual failure rate of the isolated PIN neurectomy group over a longer period of time. Moreover, the width of the 95% confidence of failure rates (especially for AIN + PIN) shows that there is a lack of precision and a lack of power in the comparison between techniques. Another limitation of the review is that non-English language studies were excluded.

Conclusions

Both isolated PIN and PIN + AIN partial wrist denervation procedures have the potential to alleviate wrist pain without sacrificing residual wrist mobility. Apparently, performing an additional AIN neurectomy does not offer greater advantages compared to the isolated PIN neurectomy. On the contrary, PIN + AIN neurectomy seems to be associated with a paradoxical increase in the failure rate in comparison with isolated PIN neurectomy. There is a need for randomised controlled trials comparing isolated PIN and AIN + PIN denervation to reach definitive conclusions.

ICMJE conflict of interest statement

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding statement

This work did not receive any specific grant from any funding agency in the public, commercial, or not-for-profit sector.

Author contribution statement

Conceptualization: LG and AF; software and statistical analysis: SN; data curation: AF, SN, LG; writing-original draft preparation: AF; writing-review, supervision and editing: LG. All authors have read and agreed to the published version of the manuscript.