Abstract
Introduction:
This prospective, one-group, interventional study assessed 5 year survival and outcomes after partial wrist denervation for painful wrist osteoarthritis. The primary outcome was the proportion of patients who did not require further surgery (survival rate). Secondary outcomes included patient-reported measures, objective function and radiographic progression.
Methods:
Sixty consecutive patients who underwent neurectomy of the posterior and anterior interosseous nerves between 2018 and 2020 were included. Survival was analysed using Kaplan–Meier and Cox regression. Patient-reported outcomes, strength and range of motion were assessed at baseline, 1 year and 5 years using generalized estimating equations. Radiographs were reviewed at baseline and 5 years later.
Results:
At 1 and 5 years, the survival probabilities were estimated to be 73 and 57%, respectively. In patients who did not require additional surgery, DASH improved by 15 points, Patient-reported Wrist Evaluation by 23 points, pain at rest by 2 points and pain on load by 3 points. No significant changes were observed in the European Quality of Life Three Dimensions or objective function. Radiographic progression was observed in 21% of patients.
Conclusion:
In summary, less than half of the patients underwent revision surgery within 5 years and those who did not require further procedures experienced significant improvements in patient-reported outcomes. Additional studies are required to confirm these findings and investigate who may benefit from partial wrist denervation.
Level of evidence:
III
Keywords
Introduction
Wrist denervation is a surgical technique in which sensory nerve branches to the articular capsule are cut to relieve wrist pain. Since Wilhelm’s description of total denervation in 1965, less extensive methods targeting the posterior interosseous nerve (PIN) and/or anterior interosseous nerve (AIN) through a single skin incision have been described (Berger, 1998; Dellon, 1985). In wrist osteoarthritis (OA), denervation is a less invasive alternative to arthrodesis, arthroplasty or proximal row carpectomy (Kadhum et al., 2020).
Significant improvements in Patient-reported Outcome Measures (PROMs) have been documented after partial wrist denervation in wrist OA (Abdelaziz et al., 2019; Swärd et al., 2022). Retrospective studies of patients with chronic wrist pain of different aetiologies, including OA, have reported reoperation rates ranging from 15 to 31% owing to persistent or recurrent symptoms, at an average of 7–26 months postoperatively (O'Shaughnessy et al., 2019; Weinstein and Berger, 2002). However, it is difficult to determine the long-term effectiveness of partial wrist denervation for wrist OA, as most previous retrospective studies assess denervation in a variety of diagnoses rather than focusing exclusively on OA, lack standardized follow-up protocols and use different outcome measures.
This prospective one-group interventional study aimed to assess the survival and outcomes of denervation of the PIN and AIN in wrist OA, 5 years after surgery. The primary objective was to determine the proportion of patients who did not require revision surgery during the follow-up period (survival rate). The secondary aims were changes in the Disabilities of the Arm, Shoulder and Hand (DASH) (Hudak et al., 1996), Patient-reported Wrist Evaluation (PRWE) (MacDermid et al., 1998), European Quality of Life Three Dimensions (EQ-5D-3L) (Brooks, 1996), objective function and radiological progression of OA. We hypothesized that partial wrist denervation could postpone or possibly eliminate the need for revision surgery in patients with wrist OA.
Methods
In this prospective single-arm interventional study, 60 consecutive patients underwent PIN and AIN neurectomy between 2018 and 2020 through a dorsal incision (Berger, 1998). One-year data from this cohort have been published in the Journal of Hand Surgery: European Volume (Swärd et al., 2022). The surgical technique and follow-up routine are documented in the original series.
Inclusion and exclusion criteria
The inclusion criteria were painful wrist OA secondary to scaphoid nonunion advanced collapse (SNAC), scapholunate advanced collapse (SLAC), distal radius fracture or Kienböck’s disease in patients aged >18 years. Patients with inflammatory arthritis, a previous ipsilateral PIN or AIN neurectomy, symptomatic instability of the ipsilateral distal radioulnar joint or inability to comply with the follow-up protocol were excluded.
Outcome measures
The primary outcome measure was 5 year postoperative survival, where the endpoint was defined as the number of months until a patient was placed on the waiting list for revision surgery owing to persistent or recurrent symptoms. The indication for revision surgery was determined by patient preference and was not dependent on radiographic findings or changes in the PROMs. Secondary outcomes were changes in DASH, PRWE, EQ-5D-3L, pain at rest and load measured by a Numerical Rating Scale (NRS, 0–10), range of motion (ROM), key pinch strength, grip strength and radiological progression of OA in survivors, 5 years after surgery. The Minimal Clinically Important Differences (MCID) were defined as 10 points for DASH (Sorensen et al., 2013), 14 for PRWE (Sorensen et al., 2013), 0.085 for EQ5D-3L (Yapp et al., 2022) and 2 points for NRS (Salaffi et al., 2004). Key pinch and grip strengths were measured in kilograms using a pinch gauge (PG-30, B&L Engineering, Santa Ana, CA, USA) and a hydraulic hand dynamometer (BL5001, B&L Engineering, Santa Ana, CA, USA), with the mean of three maximal efforts recorded. ROM was assessed using a goniometer in 5° increments according to the “National manual for measuring motion and strength in the elbow, forearm and hand” (HAKIR, n.d.). Posteroanterior and lateral radiographs taken 5 years postoperatively were compared with baseline radiographs to assess radiological OA progression. In the SLAC and SNAC groups, progression was defined as an increased SLAC or SNAC stage (Vender et al., 1987; Watson and Ballet, 1984). Osteoarthritis progression caused by a distal radius fracture or Kienböck’s disease was defined as an increase in the OA stage according to the Kellgren–Lawrence classification (Kellgren and Lawrence, 1957).
Statistical analysis
This study is a secondary analysis of the long-term outcomes of a previously conducted single-arm interventional study. Therefore, no prospective power calculations were carried out for this analysis. The available sample size was determined by the original study cohort (n = 60) and the number of patients available for long-term follow-up.
Descriptive statistics are presented as medians and IQR. Kaplan–Meier and Cox regression analyses were carried out to analyse survival. In patients who did not require revision surgery during follow-up, longitudinal data (grip strength, key pinch, ROM and PROMs) were analysed using generalized estimating equations (GEE). A robust estimator covariance matrix, autoregressive working correlation matrix and linear models were selected for all variables. Changes in outcome variables over time, as well as the effects of predictors, were reported as beta coefficients (β) with p-values. The beta coefficient represents the mean change in the outcome variable from the preoperative measurement to the 5 year postoperative assessment. Age and sex were included as covariates in both Cox regression and GEE analyses. Statistical significance was set at p < 0.05. Statistical analyses were carried out using R version 4.4.2.
Results
The median age at baseline was 62 years (IQR 55-71). Forty-three patients were men (72%). Thirty-two patients were manual workers, seven were non-manual workers and 21 were retired. The most common type of arthritis was SLAC (n = 43), followed by SNAC (n = 11), distal radius fracture (n = 4) and Kienböck's disease (n = 2).
A flowchart of patient selection is presented in Figure 1. Within the first postoperative year, 16 patients (27%) were scheduled for revision surgery: seven before the 12 month follow-up and nine at the follow-up visit. Over the subsequent 4 years, an additional nine patients (15%) required revision surgery. The revision rates were 49% for SLAC, 27% for SNAC, 0% for distal radius fracture and 0% for Kienböck’s disease. At the 1 and 5 year follow-ups, Kaplan–Meier analysis estimated the overall survival probability to be 73% (95% CI: 62–85%) and 57% (95% CI: 45–71%), respectively (Figure 2). A complementary Cox regression analysis showed that neither age nor sex was a statistically significant predictor of survival.
Flowchart of patient follow-up and dropout.
Kaplan–Meier survival curve for partial wrist denervation.
The preoperative and postoperative PROM values for revision cases and survivors are presented in Table 1. The sample size was insufficient to conduct statistical analyses of group differences in the PROMs. DASH, PRWE, pain at rest and pain on load improved significantly above the MCID levels in patients who did not require additional surgery during follow-up; however, there was no improvement in EQ-5D-3L (Table 2). There were no significant changes in grip strength, pinch strength or ROM apart from a minimal clinically insignificant decrease in supination and an increase in ulnar deviation, probably owing to measurement variation. Older age predicted worse DASH and PRWE-score (β = 0.46 (p = 0.001) and β = 0.46 (p = 0.001)) and higher pain on load (β = 0.05 (p = 0.004)) at follow-up. Sex difference had no effect on DASH, PRWE or pain at rest scores.
Preoperative and last available postoperative PROM values in survival and revision groups.
Values are presented as median (IQR).
DASH: Disabilities of the Arm, Shoulder and Hand; PRWE: Patient-Rated Wrist Evaluation; NRS: Numerical Rating Scale; EQ-5D-3L: EuroQol-5D-3L.
Effects of denervation surgery in patients who did not need additional surgery during follow up.
Generalized estimating equations results expressed as beta coefficients: expected population average change of the outcome variable between the assessments (p-value). Corrected for age and sex.
DASH: Disabilities of the Arm, Shoulder and Hand; PRWE: Patient-Rated Wrist Evaluation; NRS: Numerical Rating Scale; EQ-5D-3L: EuroQol-5D-3L.
Among the 26 patients who did not require revision surgery and were assessed 5 years postoperatively, 10 had retired at baseline and an additional four retired during the 5 year follow-up period. Six patients continued their heavy manual labour, while four transitioned to sedentary work. Two patients remained office-based employees throughout the study period. Radiographic progression of OA was observed in five of the 24 patients (21%) who did not require revision surgery and were available for radiological assessment at the 5 year follow-up.
Discussion
In this wrist OA cohort, most revision surgeries after partial wrist denervation occurred within the first postoperative year, after which the procedure-free survival stabilized. Patients without revision during the 5 year follow-up showed considerable improvements in DASH and PRWE scores over time.
Few studies have investigated the medium- or long-term effects of partial wrist denervation in wrist OA and randomized trials are lacking. Most previous studies have assessed survival and PROMs in heterogeneous cohorts, including patients with wrist instability, idiopathic pain, OA and inflammatory arthritis. Few studies have specifically addressed survival and PROMs in OA populations. In this OA study comprising 90% SLAC or SNAC wrists, we present estimated 1 and 5 year survival probabilities of 73 and 57%, respectively. The short-term survival is slightly lower than the 85% survival at a mean of 7 months postoperatively reported by Weinstein and Berger (2002) in a cohort in which 70% of patients had OA. Similarly, O’Shaughnessy et al. (2019) found a 1 year survival rate of 85% in a mixed OA and inflammatory arthritis population. Symptoms of inflammatory arthritis may vary with time and medication, possibly explaining the higher short-term survival compared with our results. The overall 5 year survival rate of 71% reported by O’Shaughnessy et al. (2019) is also notably higher than that in the present study. However, their 59% survival rate in the SLAC/SNAC subgroup is consistent with our findings. Similar to previous studies (O’Shaughnessy et al., 2019; Weinstein and Berger, 2002), we found that the most substantial decline in survival occurred within the first 12 months, indicating that patients with satisfactory outcomes at 1 year are less likely to require further surgery.
Small but significant improvements were reported for DASH and PRWE scores in this cohort 1 year after surgery (Swärd et al., 2022). Five years postoperatively, we observed highly significant improvements in DASH and PRWE scores of 15 and 23 points, respectively, in the group of patients who did not require revision surgery during follow-up. Similarly, Abdelaziz et al. (2019) presented an average improvement in DASH of 15 points at 12–30 months after surgery in 30 wrists with SLAC or SNAC arthritis undergoing PIN neurectomy. The improvements reported in the present study are well above the reported MCID levels of 10 and 14 for the DASH and PRWE respectively (Sorensen et al., 2013). The long-term improvement could partly be attributed to reduced activity levels aimed at avoiding symptoms or to the fact that eight patients either retired or transitioned from manual to sedentary work during the follow-up period. However, these factors are unlikely to fully explain the improvements in PROMs, suggesting that partial wrist denervation may improve long-term outcomes in some patients. Owing to the small sample size, we could not identify which patients might benefit from this procedure; therefore, additional research is needed.
In contrast to O’Shaughnessy et al. (2019), who reported radiographic progression of OA in 47% of cases after an average follow-up of 5 years after surgery, we observed progression in only 21% of cases. This difference may be due to our stricter definition of progression, which required an increase of at least one grade in established OA classification systems, whereas O’Shaughnessy et al. defined progression based on any increase in subchondral sclerosis, joint space narrowing, cysts or osteophytes.
The main strengths of this study are its prospective design and structured follow-up of a population exclusively affected by OA. The primary limitation is the absence of a control group, which increases susceptibility to bias and precludes definitive attribution of the observed effects to the intervention rather than to placebo effects, natural disease progression or confounding variables. Symptom regression to the mean is well documented in OA trials (Englund and Turkiewicz, 2025) and could explain the improvements in PROMs. In addition, the placebo effect cannot be disregarded in OA treatment (Zhang et al., 2008), with a reported substantial and stable effect on subjective outcomes for at least a year post-surgery in unaware patients (Wartolowska et al., 2016, 2017). However, the persistence of the placebo effect in the long-term follow-up of aware patients, as in the present study, remains uncertain and possibly less likely.
In conclusion, we found an overall survival probability above 50% at 5 years after partial wrist denervation in painful wrist OA. Additionally, denervation resulted in long-term clinically important improvements in PROMs in patients who did not require revision surgery during follow-up. These findings suggest that partial wrist denervation may delay, or in some cases eliminate, the need for revision surgery in patients with wrist OA. Additional studies with larger patient cohorts are needed to verify these results and investigate who may benefit from this procedure.
Footnotes
Acknowledgements
We thank research assistant nurse Maria Berghall at the Department of Hand Surgery at Södersjukhuset, Stockholm, for administrative assistance and biostatistician Mikael Andersson Franko at the Department of Clinical Science and Education at Södersjukhuset, Stockholm for statistical support with this study.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The study was funded by AFA research fund.
Ethical approval
Ethical approval for this study was obtained from the Regional Ethics Committee of Stockholm (DN 2017/2114-31/2, with a complementary permission to do a 5 year follow-up, DN 2022-04410-02).
Informed consent
Written informed consent was obtained from all subjects before enrollment.
Trial registration
NCT03378362 Study Details | Pain Relief and Functional Outcome After Partial Denervation of the Wrist | ClinicalTrials.gov
Previous publication
The one-year results were published in JHSE 2022 by Swärd et al (Swärd EM, Franko MA, Wilcke MK. The effects of partial wrist denervation in wrist osteoarthritis: patient-reported outcomes and objective function. J Hand Surg Eur Vol. 2022; 47(8): 798–804).
