A Systematic Review on Long-Term Postsurgical Pain Outcomes; What Is the Effect of Upper Extremity Regional Anesthesia?

BACKGROUND: Chronic pain is a recognized complication of surgery, and it has been hypothesized that regional anesthesia might reduce the risk of development of chronic pain after upper extremity surgery. METHODS: A systematic literature review was performed to assess whether in patients undergoing elective upper extremity surgery (P), regional anesthesia (I), compared to general anesthesia (C), would result in lower long-term (>3 months) postoperative pain intensity (O). We included randomized and nonrandomized controlled trials (RCTs). Our primary outcome was numerical rating score or visual analogue scale for pain, at >3 months postoperatively. The Embase, Medline ALL, Web of Science Core Collections, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for all reports assessing pain at >3 months after upper extremity surgery under general versus regional anesthesia. Secondary outcomes were: opioid prescription filling, complex regional pain syndrome (CRPS) incidence, the Mayo Wrist Score (MWS), and scores on the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. Quality (or certainty) of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Risk-of-bias was assessed using the Cochrane tool for randomized trials (RoB 2.0) and nonrandomized trials (ROBINS-I). RESULTS: This review included 14 studies, comprising 7 RCTs and 7 nonrandomized studies. Six of the 7 studies (4 RCTs, N = 273; 2 nonrandomized studies, N = 305) using a pain score, our primary outcome, report comparable long-term postoperative pain scores after regional and general anesthesia. Six of the 7 studies using our secondary outcomes report comparable long-term outcomes in terms of opioid prescription filling (2 retrospective cohort studies [RCSs], N = 89,256), CRPS incidence (1 RCT, N = 301), MWS (1 RCT and 1 RCS, N = 215), and DASH score (1 RCT, N = 36). Comparable outcomes were reported in all 7 RCTs (N = 778) and in 5 of the 7 nonrandomized studies, comprising 5 RCSs (N = 89,608). Two prospective observational studies (POSTs), comprising 279 patients, report a statistically significant difference in outcomes, with less pain and better DASH scores after brachial plexus anesthesia. All 14 studies provided moderate to very low certainty evidence, and there was a serious risk of bias due to confounding bias in 5 of the 7 nonrandomized studies (N = 631). CONCLUSIONS: The results of this review indicate that upper extremity regional anesthesia, compared to general anesthesia, is unlikely to change pain intensity at >3 months postoperatively.

Anatomic Variations and Malformations as Rare Causes of Median Nerve Compression in Adults: A Narrative Review.

OBJECTIVE: The median nerve can become compressed at multiple points in the arm, causing carpal tunnel-, pronator-, anterior interosseous-, or lacertus syndrome. Anatomical variations are potential reasons of persisting or recurrent symptoms of median nerve compression and are often recognized late. The objective of this study is to provide a comprehensive list of rare anatomical variations and malformations causing median nerve compression. METHODS: A total of 62 studies describing median nerve compression due to an anatomical structure in adults published from 2000 in English were included. The findings were: 35 tenomuscular, 16 vascular causes, and 4 cases with nerve involvement. Only 1 osseous and 18 combined anomalies caused compression. In 18 cases, the anomaly was found in the proximal forearm. RESULTS: In 44 cases, the median nerve was surgical released and 35 anomalies were completely resected. Persistent or recurrent symptoms were present in 13 cases. During follow-up, 1 case of recurrence was reported.Standard operative option for median nerve compression consists of an open median nerve release. CONCLUSIONS: In case of persistent or recurrent carpal tunnel syndrome, unilateral symptoms, the presence of a palpable mass, manifestation of symptoms at young age and pain in the forearm or upper arm, the surgeon has to rule out the presence of an anatomical anomaly. Complete resection of the anomaly is not always necessary. The surgeon should be aware of potential anomalies to avoid inadvertent damage at surgery.

Outcome of Simple Decompression of Primary Cubital Tunnel Syndrome Based on Patient-Reported Outcome Measurements.

PURPOSE: To evaluate the patient-reported outcome measures of patients with primary cubital tunnel syndrome and to assess whether they are affected by preoperative symptom severity. METHODS: Patients who underwent simple decompression for primary cubital tunnel syndrome were selected from a prospectively maintained database. Outcome measurements consisted of the Boston Carpal Tunnel Questionnaire at intake and at 3 and 6 months after surgery. Also, 6 months after surgery, the patients received a question about their satisfaction with the treatment result. To determine a possible influence of preoperative symptom severity on postoperative outcomes, the sample was divided into quartiles based on symptom severity at intake. RESULTS: One hundred and forty-five patients were included in the final analysis. On average, all patients improved on the Boston Carpal Tunnel Questionnaire. The subgroup of patients with the mildest symptoms at intake did not improve significantly on symptom severity but did improve significantly on their functional status. In addition, the patients with the most severe symptoms at intake did improve on both aspects. Moreover, no difference in satisfaction with treatment result between the severity of symptoms at intake was found. CONCLUSIONS: The patients with the mildest symptoms at intake may not improve on symptom severity, but they do improve on functional status after simple decompression for cubital tunnel syndrome. In addition, patients with the most severe symptoms at intake do improve on both symptom severity and functional status. Moreover, all patients reported to be equally satisfied with the treatment result, which suggests that satisfaction is not dependent on the symptom severity at intake. Even those patients with both the mildest symptoms before surgery and the least improvement still seem to benefit from simple decompression. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Surgical technique: hemi-extensor carpi radialis brevis tenodesis for stabilizing the midcarpal joint in Ehlers-Danlos syndrome.

Patients with the hypermobility type of Ehlers-Danlos (EDS-HT) often complain of wrist pain, usually originating from subluxations. As a result of the laxity, wrist function in these patients can be highly limited. This paper presents a surgical technique that stabilizes the lunocapitate joint with the use of an extensor carpi radialis brevis strip. Five patients with confirmed EDS-HT were treated with an extensor carpi radialis brevis tenodesis for their midcarpal instability. Two patients presented with complications following surgery, one major and one minor. This paper presents a potentially satisfactory surgical solution to recurrent midcarpal instability in EDS-HT patients and demonstrates that the use of an autologous tendon might be feasible in spite of a background of abnormal collagen metabolism.

The effectiveness of acellular nerve allografts compared to autografts in animal models: A systematic review and meta-analysis.

BACKGROUND: Treatment of nerve injuries proves to be a worldwide clinical challenge. Acellular nerve allografts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous nerve graft. OBJECTIVE: To systematically review the efficacy of the acellular nerve allograft, its difference from the gold standard (the nerve autograft) and to discuss its possible indications. MATERIAL AND METHODS: PubMed, Embase and Web of Science were systematically searched until the 4th of January 2022. Original peer reviewed paper that presented 1) distinctive data; 2) a clear comparison between not immunologically processed acellular allografts and autologous nerve transfers; 3) was performed in laboratory animals of all species and sex. Meta analyses and subgroup analyses (for graft length and species) were conducted for muscle weight, sciatic function index, ankle angle, nerve conduction velocity, axon count diameter, tetanic contraction and amplitude using a Random effects model. Subgroup analyses were conducted on graft length and species. RESULTS: Fifty articles were included in this review and all were included in the meta-analyses. An acellular allograft resulted in a significantly lower muscle weight, sciatic function index, ankle angle, nerve conduction velocity, axon count and smaller diameter, tetanic contraction compared to an autologous nerve graft. No difference was found in amplitude between acellular allografts and autologous nerve transfers. Post hoc subgroup analyses of graft length showed a significant reduced muscle weight in long grafts versus small and medium length grafts. All included studies showed a large variance in methodological design. CONCLUSION: Our review shows that the included studies, investigating the use of acellular allografts, showed a large variance in methodological design and are as a consequence difficult to compare. Nevertheless, our results indicate that treating a nerve gap with an allograft results in an inferior nerve recovery compared to an autograft in seven out of eight outcomes assessed in experimental animals. In addition, based on our preliminary post hoc subgroup analyses we suggest that when an allograft is being used an allograft in short and medium (0-1cm, > 1-2cm) nerve gaps is preferred over an allograft in long (> 2cm) nerve gaps.

Incidence of Chronic Postsurgical Pain after Upper Extremity Surgery and its Correlation with Preoperative Pain.

The incidence of chronic postsurgical pain (CPSP) after upper extremity surgery is not known. The goal was to study CPSP at 5 years postoperative and to investigate patient, surgical, and anesthetic risk factors. Methods: Patients scheduled for elective upper extremity surgery were included, and numeric rating scale (NRS) score for pain was obtained preoperatively and at 5 years postoperatively. According to the International Association for the Study of Pain definition, CPSP was defined as an increase in NRS compared with preoperatively. Results: A total 168 patients were contacted at 5 years postoperatively. Incidence of CPSP was 22%, and 35% had an NRS score of 4 or more. The number of patients with an NRS score of 0 and with an NRS score of 4 or more preoperatively was higher in the no-CPSP group, with P values of 0.019 and 0.008, respectively. Of the patients with no preoperative pain, 34% developed CPSP. Regional anesthesia was associated with a lower CPSP incidence (P = 0.001) and was more frequently applied in surgery on bony structures and in patients with a preoperative NRS score of 4 or more. Conclusions: The incidence CPSP was 22%. Patients with no pain or an NRS score of 4 or more preoperatively were less likely to develop CPSP, but individual susceptibility to pain and success of the surgery may be of influence. One-third of the patients with no preoperative pain developed CPSP. More studies are needed to reveal the exact relation between brachial plexus anesthesia and CPSP.

Conservative Treatment of Ulnar Nerve Compression at the Elbow: A Systematic Review and Meta-Analysis.

Background The clinical results of conservative treatment options for ulnar compression at the elbow have not been clearly determined. The aim of this review was to evaluate available conservative treatment options and their effectiveness for ulnar nerve compression at the elbow. Methods In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a systematic review and meta-analysis of studies was performed. Literature search was performed using Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). Results Of the 1,079 retrieved studies, 20 were eligible for analysis and included 687 cases of ulnar neuropathy at the elbow. Improvement of symptoms was reported in 54% of the cases receiving a steroid/lidocaine injection (95% confidence interval [CI], 41-67) and in 89% of the cases using a splint device (95% CI, 69-99). Conclusions Conservative management seems to be effective. Both lidocaine/steroid injections and splint devices gave a statistically significant improvement of symptoms and are suitable options for patients who refuse an operative procedure or need a bridge to their surgery. Splinting is preferred over injections, as it shows a higher rate of improvement.

Motor and sensory nerve transfers in the lower extremity: Systematic review of current reconstructive possibilities.

BACKGROUND: Peripheral nerve injuries (PNI) are predominantly treated by anatomical repair or reconstruction with autologous nerve grafts or allografts. Motor nerve transfers for PNI in the upper extremity are well established; however, this technique is not yet widely used in the lower extremity. This literature review presents an overview of the current options and postoperative results for nerve transfers as a treatment for nerve injury in the lower extremity. METHODS: A systematic search in PubMed and Embase databases was performed. Full-text English articles describing surgical procedures and postoperative outcomes of nerve transfers in the lower extremity were included. The primary outcome was postoperative muscle strength measured using the British Medical Research Council (MRC) scale, with MRC> 3 considered good and postoperative return of sensation reported according to the modified Highet classification. RESULTS: A total of 36 articles for motor nerve transfer and 7 for sensory nerve transfer were included. Sixteen articles described motor nerve transfers for treating peroneal nerve injury, 17 for femoral nerve injury, 2 for tibial nerve injury, and one for obturator nerve injury. Transfers of multiple branches to restore deep peroneal nerve function led to a good outcome in 58% of patients and 43% when a single branch was used as a donor. The transfer of multiple branches for femoral nerve or obturator nerve repair was performed in all reported patients with a good outcome. CONCLUSIONS: The transfer of motor nerves for the recovery of PNI is a feasible technique with relatively low risks and great benefits. The correct indication, timing, and surgical technique are essential for optimizing results.

Spatiotemporal dynamics of re-innervation and hyperinnervation patterns by uninjured CGRP fibers in the rat foot sole epidermis after nerve injury.

The epidermis is innervated by fine nerve endings that are important in mediating nociceptive stimuli. However, their precise role in neuropathic pain is still controversial. Here, we have studied the role of epidermal peptidergic nociceptive fibers that are located adjacent to injured fibers in a rat model of neuropathic pain. Using the Spared Nerve Injury (SNI) model, which involves complete transections of the tibial and common peroneal nerve while sparing the sural and saphenous branches, mechanical hypersensitivity was induced of the uninjured lateral (sural) and medial (saphenous) area of the foot sole. At different time points, a complete foot sole biopsy was taken from the injured paw and processed for Calcitonin Gene-Related Peptide (CGRP) immunohistochemistry. Subsequently, a novel 2D-reconstruction model depicting the density of CGRP fibers was made to evaluate the course of denervation and re-innervation by uninjured CGRP fibers. The results show an increased density of uninjured CGRP-IR epidermal fibers on the lateral and medial side after a SNI procedure at 5 and 10 weeks. Furthermore, although in control animals the density of epidermal CGRP-IR fibers in the footpads was lower compared to the surrounding skin of the foot, 10 weeks after the SNI procedure, the initially denervated footpads displayed a hyper-innervation. These data support the idea that uninjured fibers may play a considerable role in development and maintenance of neuropathic pain and that it is important to take larger biopsies to test the relationship between innervation of injured and uninjured nerve areas.

Rare Tumors Causing Median Nerve Compression in Adults-A Narrative Review.

The median nerve can be compressed due to a tumor along the course of the median nerve, causing typical compression symptoms or even persistence or recurrence after an operation. The aim of this review is to provide a comprehensive overview of rare tumors described in recent publications that cause median nerve compression and to evaluate treatment options. The PubMed, Embase, and Web of Science databases were searched for studies describing median nerve compression due to a tumor in adults, published from the year 2000 and written in English. From 94 studies, information of approximately 100 patients have been obtained. Results The rare tumors causing compression were in 32 patients located at the carpal tunnel, in 21 cases in the palm of the hand, and 28 proximal from the carpal tunnel. In the other cases the compression site extended over a longer trajectory. There were 37 different histological types of lesions. Complete resection of the tumor was possible in 58 cases. A total of 8 patients presented for the second time after receiving initial therapy. During follow-up, three cases of recurrence were reported with a mean follow-up period of 11 months. The most common published cause of median nerve compression is the lipofibromatous hamartoma. Besides the typical sensory and motor symptoms of median nerve compression, a thorough physical examination of the complete upper extremity is necessary to find any swelling or triggering that might raise suspicion of the presence of a tumor.

Forearm Plate Fixation: Should Plates Be Removed?

Background: Refracture after both bone forearm fracture fixation may vary with or without plate removal. We tested the null hypothesis that there is no difference in the rate of refracture in patients who have undergone open reduction and internal fixation of a diaphyseal forearm bone who have retained implants versus removed implants. We also studied factors associated with plate removal. Methods: We retrospectively identified 645 adult patients with a total of 925 primary fractures that underwent primary plate fixation of an ulnar or radial shaft fracture between 2002 and 2015 at a single institutional system. Patients with nonunion, pathological fracture or infection were excluded. Independent factors associated with refracture and plate removal were identified using multivariable analysis. Results: Refractures occurred in 6.3% of the fractures that had forearm implant removal, compared to 2.1% of the fractures with retained plates. Refractures were independently associated with plate removal (OR: 3.7, 95% CI: 1.2-11.7, P=0.023) and was more frequent in the radius (OR: 2.4, 95% CI: 1.0-5.8, P=0.06). A refracture after implant removal occurred within 3 months after removal. Ulnar plates were removed more often compared to radial plates (OR: 2.6, 95% CI: 1.4-4.7, P=0.002) as were plates used for type A fractures compared to type C fractures (OR: 3.2, 95% CI: 1.1-9.2, P=0.032). Conclusion: The rate of refracture is higher after plate removal compared to patients who did not have plates removed. Although uncommon, refractures of the radius tend to be more common than a refracture of the ulna. If the implant is symptomatic on the ulnar side, it may be preferable to remove the ulnar implant and retain the radius implant rather than remove both plates when possible. Furthermore, limiting strenuous activity for three months after implant removal is a consideration.

Is the outcome of a revision carpal tunnel release as good as those of a primary release? A matched cohort study.

OBJECTIVE: This study aimed to compare primary and revision carpal tunnel release outcomes in all patients with carpal tunnel syndrome and when corrected for baseline severity and demographics. METHODS: A total of 903 hands of primary and 132 hands of revision patients underwent carpal tunnel release and patients completed online questionnaires on demographics, clinical severity, and satisfaction. The primary outcome measure, the Boston Carpal Tunnel Questionnaire (BCTQ), was administered at intake and six months after surgery. RESULTS: The BCTQ total score at six months was better in primary (1.55±0.58) than revision patients (1.94±0.73, p=<0.001), and primary patients improved more on the BCTQ total score (1.10±0.71 vs. 0.90±0.72, p=0.003). In patients matched on similar baseline characteristics using propensity score matching, the BCTQ total score at six months was also better in primary patients (1.65±0.63) than in revision patients (1.92±0.73, p=0.002), and primary patients still had more improvement in BCTQ total score (1.18±0.73 vs. 0.89±0.73, p=0.004). CONCLUSIONS: This study shows that the outcome after revision carpal tunnel release is only 16% worse compared to primary carpal tunnel release. Preoperative symptom severity, functional status, and demographics may play a role since correcting for these factors reduces the difference in outcome between primary and revision CTR.

Systematic review and meta-analysis of surgical options for recurrent or persistent carpal tunnel syndrome: simple decompression versus coverage of the median nerve.

We performed a systematic review on the success of different surgical techniques for the management of recurrent and persistent carpal tunnel syndrome. Twenty studies met the inclusion criteria and were grouped by the type of revision carpal tunnel release, which were simple open release, open release with flap coverage or open release with implant coverage. Meta-analysis showed no difference, and pooled success proportions were 0.89, 0.89 and 0.85 for simple open carpal tunnel release, additional flap coverage and implant groups, respectively. No added value for coverage of the nerve was seen. Our review indicates that simple carpal tunnel release without additional coverage of the median nerve seems preferable as it is less invasive and without additional donor site morbidity. We found that the included studies were of low quality with moderate risk of bias and did not differentiate between persistent and recurrent carpal tunnel syndrome.

Nerve recovery from treatment with a vascularized nerve graft compared to an autologous non-vascularized nerve graft in animal models: A systematic review and meta-analysis.

BACKGROUND: Treatment of nerve injuries proves to be a worldwide clinical challenge. Vascularized nerve grafts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous non-vascularized nerve graft. However, there is no adequate clinical evidence for the beneficial effect of vascularized nerve grafts and they are still disputed in clinical practice. OBJECTIVE: To systematically review whether vascularized nerve grafts give a superior nerve recovery compared to non-vascularized nerve autografts regarding histological and electrophysiological outcomes in animal models. MATERIAL AND METHODS: PubMed and Embase were systematically searched. The inclusion criteria were as follows: 1) the study was an original full paper which presented unique data; 2) a clear comparison between a vascularized and a non-vascularized autologous nerve transfer was made; 3) the population study were animals of all genders and ages. A standardized mean difference and 95% confidence intervals for each comparison was calculated to estimate the overall effect. Subgroup analyses were conducted on graft length, species and time frames. RESULTS: Fourteen articles were included in this review and all were included in the meta-analyses. A vascularized nerve graft resulted in a significantly larger diameter, higher nerve conduction velocity and axonal count compared to an autologous non-vascularized nerve graft. However, during sensitivity analysis the effect on axonal count disappeared. No significant difference was observed in muscle weight. CONCLUSION: Treating a nerve gap with a vascularized graft results in superior nerve recovery compared to non-vascularized nerve autografts in terms of axon count, diameter and nerve conduction velocity. No difference in muscle weight was seen. However, this conclusion needs to be taken with some caution due to the inherent limitations of this meta-analysis. We recommend future studies to be performed under conditions more closely resembling human circumstances and to use long nerve defects.

Patient Mindset and the Success of Carpal Tunnel Release.

BACKGROUND: Depression and pain catastrophizing are aspects of the patient's mindset that have been shown to be important in relation to the outcome of carpal tunnel release. However, other factors of the patient's mindset have been understudied, such as treatment expectations and illness perceptions. The aim of the present study was to investigate the influence of these mindset aspects on outcome of carpal tunnel release, in addition to psychological distress and pain catastrophizing. METHODS: A total of 307 patients with carpal tunnel syndrome who visited outpatient hand surgery clinics and who completed online questionnaires regarding demographic and psychosocial characteristics and carpal tunnel syndrome severity were included. The patient mindset was measured with the Patient Health Questionnaire-4, the Pain Catastrophizing Scale, the Credibility Expectancy Questionnaire, and the Brief Illness Perception Questionnaire. Hierarchical linear regression models were used to examine the relation between self-reported severity 6 months after carpal tunnel release, as measured with the Boston Carpal Tunnel Questionnaire, and psychosocial aspects of mindset, adjusting for preoperative Boston Carpal Tunnel Questionnaire score, patient characteristics, and comorbidities. RESULTS: Independent associations with better self-reported outcome were found for higher treatment expectations (ß = -0.202; p < 0.001) and illness comprehensibility (ß = -0.223; p < 0.001). The additional explained variance in Boston Carpal Tunnel Questionnaire scores by the patient's mindset was 13.2 percent (psychological distress and pain catastrophizing together, 2.1 percent; treatment expectations and illness perceptions together, 11.1 percent). CONCLUSION: Treatment outcome expectations and comprehensibility of illness are both independently associated with the outcome of carpal tunnel release, showing the importance of these aspects of the patient's mindset for the outcome of carpal tunnel release. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Histological validation of ultrasound-guided neurography in early nerve regeneration.

Ultrasound-guided near-nerve neurography is a new tool that can be used to assess nerve regeneration before reinnervation occurs. In this study, ultrasound-guided near-nerve measurements were validated against axon diameter counts in rabbits during a 15-week regeneration period after a crush lesion of their peroneal nerve. The course of the nerve was determined ultrasonically, and the active near-nerve needle electrode was maneuvered just next to the nerve under ultrasound guidance. Measured action potentials were compared with axon diameter counts from histological sections of these same nerves. A moderate to good positive correlation was found, which reached a maximum of 0.7 at a cut-off of 3 microm, corresponding to the minimal size of the myelinated axons. Our results suggest that, following a similar validation study in humans, ultrasound-guided near-nerve neurography may be clinically useful when early evaluation of nerve activity is needed.

Recurrent and persistent carpal tunnel syndrome: predicting clinical outcome of revision surgery.

OBJECTIVE: The aim of this study was to evaluate the self-reported outcome of revision surgery in patients with recurrent and persistent carpal tunnel syndrome (CTS) and to identify predictors of clinical outcome of revision surgery. METHODS: A total of 114 hands in 112 patients were surgically treated for recurrent and persistent CTS in one of 10 specialized hand clinics. As part of routine care, patients were asked to complete online questionnaires regarding demographic data, comorbidities, and clinical severity measures. The Boston Carpal Tunnel Questionnaire (BCTQ) was administered at intake and at 6 months postoperatively to evaluate clinical outcome. The BCTQ comprises the subscales Symptom Severity Scale (SSS) and Functional Status Scale (FSS), and the individual scores were also assessed. Using multivariable regression models, the authors identified factors predictive of the outcome as measured by the BCTQ FSS, SSS, and total score at 6 months. RESULTS: Revision surgery significantly improved symptoms and function. Longer total duration of symptoms, a higher BCTQ total score at intake, and diagnosis of complex regional pain syndrome (CRPS) along with CTS were associated with worse outcome after revision surgery at 6 months postoperatively. The multivariable prediction models could explain 33%, 23%, and 30% of the variance in outcome as measured by the FSS, SSS, and BCTQ total scores, respectively, at 6 months. Although patients with higher BCTQ scores at intake have worse outcomes, they generally have the most improvement in symptoms and function. CONCLUSIONS: This study identified total duration of symptoms, BCTQ total score at intake, and diagnosis of CRPS along with CTS as predictors of clinical outcome and confirmed that revision surgery significantly improves self-reported symptoms and function in patients with recurrent and persistent CTS. Patients with more severe CTS symptoms have greater improvement in symptoms at 6 months postoperatively than patients with less severe CTS, but 80% of patients still had residual symptoms 6 months postoperatively. These results can be used to inform both patient and surgeon to manage expectations on improvement of symptoms.

Influence of illness perceptions, psychological distress and pain catastrophizing on self-reported symptom severity and functional status in patients with carpal tunnel syndrome.

OBJECTIVE: To examine the influence of illness perceptions, pain catastrophizing and psychological distress on self-reported symptom severity and functional status in patients diagnosed with carpal tunnel syndrome (CTS). METHODS: A total of 674 patients with CTS scheduled for surgery at an outpatient treatment center for hand and wrist conditions (September 2017 to August 2018) completed online questionnaires regarding demographic and psychosocial characteristics and self-reported CTS severity. Self-reported severity of CTS was measured with the functional status scale and the symptom severity scale of the Boston Carpal Tunnel Questionnaire. To measure psychosocial factors, the Patient Health Questionnaire-4, Pain Catastrophizing Scale and the Brief Illness Perception Questionnaire were used. Pearson correlation coefficients were calculated to assess univariable relations. Hierarchical linear regression models were used to examine the relation between psychosocial factors and self-reported severity, and the relative contribution of psychosocial factors to self-reported severity, adjusting for patient characteristics and comorbidities. RESULTS: Medium-sized correlations (range 0.32-0.44) with self-reported severity were observed for psychological distress, pain catastrophizing, consequences, identity, concern and emotional representation. Furthermore, these factors (except for concern) were also associated with self-reported severity, when adjusted for baseline characteristics and comorbidities. Hierarchical linear regression models showed that these psychosocial factors explained an additional 20-25% of the variance in self-reported severity of CTS. CONCLUSION: This study shows that psychological distress, pain catastrophizing and illness perceptions play an independent role in self-reported severity of CTS. Clinicians should take these psychosocial factors into account when they are consulted by patients with CTS.

Ultrasound-guided near-nerve neurography for early evaluation of nerve regeneration.

For early assessment of axonal outgrowth after trauma, the nerve is surgically exposed to enable compound nerve action potential (CNAP) recordings across the lesion site. Near-nerve neurography, with needle electrodes placed transcutaneously near the nerve, could be a minimally invasive alternative if the needle placement procedure and low reproducibility are improved. We developed ultrasound-guided near-nerve neurography, which facilitates needle placement, and assessed its potential for evaluating nerve regeneration. Measurements were performed at varying times after crush lesion of the peroneal nerve of 25 rabbits. To test if ultrasound-guided near-nerve signals could be measured prior to muscle reinnervation, they were compared with recordings of compound muscle action potentials. A comparison with conventional intra-operative CNAP recordings was made by measuring nerve signal amplitude with both techniques and by assessing reproducibility. In all cases where intra-operative signals could be measured, near-nerve signals were also detected. Compound nerve activity could be recorded after 5 weeks, whereas compound muscle activity appeared after approximately 8 weeks. Reproducibility was slightly better for near-nerve than for intra-operative recordings. We conclude that ultrasound-guided near-nerve neurography is able to assess nerve regeneration well before compound muscle activity can be detected. Its accuracy and reproducibility are similar to those of conventional intra-operative recordings.