Endoscopic Revision of Carpal Tunnel Release

Clinical evaluation of post-surgical scar hyperaesthesia: a longitudinal observational pilot study

Introduction

The mechanisms underlying persistent scar pain are not fully elucidated and evidence for the clinical evaluation of scar pain is limited. This pilot observational study investigated participation data and sought to identify objective clinical scar evaluation measures for future trials.

Methods

With ethical approval and consent, adults undergoing planned hand surgery were enrolled from one NHS hospital. At 1- and 4-months post-surgery scar thermal and mechanical pain thresholds were evaluated with quantitative sensory testing; peri-scar inflammation with infrared thermometry and pliability with durometry. Participation data were analysed with descriptive statistics; the association of clinical measures with patient reported scar pain was analysed.

Results

Twenty-one participants (22% eligible patients) enrolled before study closure due to the COVID-19 pandemic; 13 completed follow up. No adverse events or dropouts resulted from clinical scar evaluation. Seventy percent of participants reported undertaking topical, nonprescription scar treatment independently. Neuropathic Pain Symptom Inventory (NPSI) scores were dispersed across the score range, capturing variability in participant-reported scar symptoms. Scar morphology, pliability and inflammation were not associated with scar pain. Differences between scar and contralateral skin in thermal and mechanical pain sensitivity were identified.

Conclusion

People with acute hand scars participate in clinical research and independently initiate scar treatment. Clinical testing of acute post-surgical hand scars is well tolerated. The NPSI demonstrates utility for exploring scar pain symptoms and may support the elucidation of mechanisms of persistent scar pain. Clinical tests of thermal and mechanical and sensitivity are promising candidate clinical measures of scar pain for future trials.

Lay Summary

Background: it is unknown why some scars remain painful long-term. We do not know if scar flexibility, inflammation or sensitivity to temperature or pressure relate to scar pain. We investigated if patients would enrol in scar research, if scar testing was tolerated and if clinical tests are useful for future scar studies. Study conduct: with ethical approval and consent, adult hand surgery patients were enrolled from one NHS hospital. Scar pain, inflammation and response to thermal, sharp and pressure tests were assessed at 1- and 4-months after surgery. Statistically, we analysed study participation, tolerance for clinical scar tests and if the scar tests related to scar pain. Findings: 21 participants (22% eligible patients) enrolled before study closure due to the COVID-19 pandemic; 13 completed follow up. No participants were injured due to scar testing. 70% of participants reported treating their scar independently. Neuropathic Pain Symptom Inventory (NPSI) allows participants to give a broad range of answers about their scar symptoms. Scores for clinical tests of scar flexibility and inflammation did not relate to participant-reported scar pain. Scars were more sensitive to tests of pin prick and cold than unaffected skin. What we learned: people with new hand scars participate in research and independently initiate scar treatment. Clinical testing of post-surgical hand scars is well tolerated. The NPSI is useful for exploring scar pain symptoms and may help us to learn about persistent scar pain. Pinprick and cold clinical tests may be useful objective pain tests for future scar research.

Reporting of scar outcomes in the hand and wrist; a state-of-the-art literature review

OBJECTIVES

The aim of this literature review was to synthesise and report current practice in evaluation and reporting of scar outcomes in hand and wrist clinical research.

METHODS

A systematic search from inception to 2022 was conducted using three electronic databases. English language randomized controlled trials and observational cohort studies reporting standardised scar outcome measures and/or scar symptoms, appearance, impairment, function, or mental health outcomes in patients with hand and wrist scars were included. Two independent reviewers determined study eligibility and performed data extraction of a priori identified scar outcome domains. Data analysis included descriptive statistics and identification of discordance in taxonomy.

RESULTS

Fifty-nine studies were included. Elective surgery cohorts were the most frequently included clinical population (n = 28; 47%) followed by burns (n = 16; 27%). Six different standardised scar outcome measures were reported by 25% of studies however only 7% of studies utilised a patient-reported measure. Scar symptoms were the most frequently reported outcome domain (81%); but taxonomy was incongruous, constructs lacked working definitions required for generalisability and outcome measurement was variable and unreported. Nineteen different measures of scar appearance and structure were reported by 30 (51%) of studies however only nine (23%) were patient-reported. Seven different hand function PROMs were reported by 25 (43%) studies. Person-centred domains including scar acceptability (12%), mental health impact (5%), and social participation (4%) were rarely reported.

CONCLUSIONS

This review highlights that evaluation and reporting of hand and wrist scar outcomes is not standardised, assessment methods and measures are under-reported and there is discordance in taxonomy. Evaluation is not person-centred, rather it is dependent on clinician assessment. Domains including scar acceptability, mental health, and social participation are rarely addressed. A stakeholder consensus derived hand and wrist scar core outcome measurement set will promote standardisation and underpin improvements in clinical research quality, transparency, and rigour.

Avive Soft Tissue Membrane Improves Outcomes of Revision Upper-extremity Nerve Decompression Surgery

Revision nerve decompression remains a challenge for surgeons. Avive Soft Tissue Membrane is processed human umbilical cord membrane that may reduce inflammation and scarring, thereby improving tissue gliding. Although synthetic conduits have been reported in revision nerve decompression, the use of Avive has not.

Methods

Prospective study of revision nerve decompression with Avive application. VAS pain, two-point discrimination, Semmes-Weinstein, pinch and grip strength, range of motion, Quick Disability of Arm, Shoulder & Hand (QuickDASH), and satisfaction were recorded. Using a propensity-matched cohort, VAS pain and satisfaction were retrospectively collected to compare with cohort outcomes.

Results

In the Avive cohort, 77 patients (97 nerves) were included. Mean follow-up was 9.0 months. Avive was applied to the median nerve in 47.4%, ulnar nerve in 39.2%, and radial nerve in 13.4%. VAS pain was 4.5 preoperatively and 1.3 postoperatively. S4 sensory recovery was achieved in 58% of patients, S3+ in 33%, S3 in 7%, S0 in 2%, and improvement from baseline in 87%. Strength improved in 92%. Mean total active motion was 94.8%. Mean QuickDASH score was 36.1, and 96% reported improved or resolved symptoms. Preoperative pain was not significantly different between Avive cohort and controls (P = 0.618). Postoperative pain was significantly lower in cohort patients (1.3 ± 2.2 versus 2.7 ± 3.0, P = 0.001). In the Avive cohort, more had improved or resolved symptoms (P < 0.0001). Clinically important improvement in pain was reported in 64.9% of Avive group patients versus 40.8% of controls (P = 0.002).

Conclusion

Avive contributes to improved outcomes in revision nerve decompression.

The distance between the distal margin of the flexor retinaculum and the radiocarpal joint as a landmark in CTS surgery: a cadaver study

BACKGROUND

The most frequent peripheral entrapment neuropathy is compression of the median nerve in the carpal tunnel, known as carpal tunnel syndrome. The most effective treatment is surgery, where the flexor retinaculum (FR¹) is divided. Nevertheless, after this operation, a significant number of patients suffer from persistent symptoms due to incomplete FR distal release. It may be difficult to identify the distal boundary of the FR due to the minimal skin incision. We aimed to identify an anatomical landmark to avoid incomplete distal FR release. The radiocarpal (RC²) joint can be palpated, and lies in close proximity to the boundaries of the FR. Thus, the distance between the RC joint space and the distal FR margin - the RC-FR distance - could be a reliable and individual morphologic measurement from easily acquired regional anthropological measurements.

METHODS

During this study, 39 radiocarpal regions of 23 embalmed cadavers were dissected, and measurements were taken. Linear regression corresponding to the ulnar length and the RC-FR distance was established.

RESULTS

The mean RC-FR distance from the RC joint space to the distal FR margin was 3.8cm (95% CI 3.5-4.0), and the range was 2.3 to 5.1cm. This distance was 1.1cm (95% CI 0.8-1.4) longer in males than in females (p < 0.00001), and there were no side-specific differences. The individual projection of the distal FR margin in centimeters can be calculated by measurement of the ipsilateral ulnar length divided by 4 and reduced by 2.9, p < 0.005.

CONCLUSIONS

The side-equal and sex-specific position of the distal flexor retinaculum margin could be calculated from the palpable radiocarpal joint space based on the ipsilateral ulnar length.

Clinical outcomes following neurolysis and porcine collagen extracellular matrix wrapping of scarred nerves in revision carpal tunnel decompression

Scar tether after primary nerve decompression can impair physiological nerve glide and vascularity of the nerve. Revision decompression in the setting of neurostenalgia should address the scarred mesoneurium in order to prevent further entrapment and tether. This study reports on the clinical outcomes of 12 patients with neurostenalgia following carpal tunnel decompression (CTD), treated with revision CTD and a porcine submucosa extracellular matrix nerve wrap (PECM) (Axoguard® nerve protector, Axogen Inc., Alachua, FL). Eleven patients had one primary decompression procedure prior to revision surgery; one patient previously had two operations for CTD. There was a significant reduction in visual analogue pain scores (VAS) and improvement in patients' satisfaction rating and symptom resolution. Patient-reported outcome measures were recorded using the Impact of Hand Nerve Disorders (I-HaND) Scale (Version 2), which demonstrated a significant reduction in hand disability. There were no complications attributable to the procedure and no re-revision procedures necessary at the latest follow-up.

Management of Recurrent Carpal Tunnel Syndrome: Systematic Review and Meta-Analysis

PURPOSE

Few comparisons have been performed between the outcomes of surgical techniques for recurrent carpal tunnel syndrome. Using a meta-analysis, this study aimed to compare the outcomes of different surgical techniques using the Boston Carpal Tunnel Questionnaire (BCTQ) and visual analog scale (VAS) for pain as outcomes.

METHODS

The following categories were used to define the study's inclusion criteria: population, intervention, comparator, outcomes, and study design. Studies were examined by 2 reviewers, and the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines were followed. The studies were assigned to 1 of the following treatment groups: decompression with or without neurolysis, autologous fat transfer, hypothenar fat pad, pedicled or free flap, and "other." For our primary outcome, we compared improvement using the BCTQ and VAS for pain between the treatment groups. For our secondary outcome, postoperative BCTQ and VAS pain values were compared.

RESULTS

Fourteen studies were included: 5 case series with postoperative data only and 9 pre-post studies without a control group. With regard to our primary outcome, the studies reported an average improvement of 1.2 points (95% confidence interval [CI][1.5, 0.9]) on a scale of 1-5 on the symptoms severity scale (SSS) of the BCTQ, 1.9 points (95% CI [1.37, 0.79]) on a scale of 1-5 on the function severity scale of the BCTQ, and 3.8 points (95% CI [4.9, 2.6]) on a scale of 1-10 on the VAS for pain. We only found significantly lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. The hypothenar fat pad group had the best reported postoperative SSS score of 1.75 (95% CI [1.24, 2.25]), function severity scale score of 1.55 (95% CI [1.20, 1.90]), and VAS pain score of 1.45 (95% CI [0.83, 2.07]).

CONCLUSIONS

All the techniques showed clinically important improvements in all the outcomes. We found lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. We found that the hypothenar fat pad group had the best reported postoperative values in our secondary analysis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Revision of Carpal Tunnel Surgery

Carpal tunnel release is one of the most commonly performed upper extremity procedures. The majority of patients experience significant improvement or resolution of their symptoms. However, a small but important subset of patients will experience the failure of their initial surgery. These patients can be grouped into persistent, recurrent, and new symptom categories. The approach to these patients starts with a thorough clinical examination and is supplemented with electrodiagnostic studies. The step-wise surgical management of revision carpal tunnel surgery consists of the proximal exploration of the median nerve, Guyon’s release with neurolysis, the rerelease of the transverse retinaculum, evaluation of the nerve injury, treatment of secondary sites of compression, and potential ancillary procedures. The approach and management of failed carpal tunnel release are reviewed in this article.

Evidence-Based Approach to Timing of Nerve Surgery: A Review

ABSTRACT

Events causing acute stress to the health care system, such as the COVID-19 pandemic, place clinical decisions under increased scrutiny. The priority and timing of surgical procedures are critically evaluated under these conditions, yet the optimal timing of procedures is a key consideration in any clinical setting. There is currently no single article consolidating a large body of current evidence on timing of nerve surgery. MEDLINE and EMBASE databases were systematically reviewed for clinical data on nerve repair and reconstruction to define the current understanding of timing and other factors affecting outcomes. Special attention was given to sensory, mixed/motor, nerve compression syndromes, and nerve pain. The data presented in this review may assist surgeons in making sound, evidence-based clinical decisions regarding timing of nerve surgery.

Management of Recalcitrant Carpal Tunnel Syndrome

Recalcitrant carpal tunnel syndrome presents a clinical challenge. Potential etiologies of persistent or recurrent symptoms after primary carpal tunnel release include incomplete nerve decompression, secondary sites of nerve compression, unrecognized anatomic variations, irreversible nerve pathology associated with chronic compression neuropathy, perineural adhesions, conditions associated with secondary nerve compression, iatrogenic nerve injury, or inaccurate preoperative diagnosis. Understanding the pertinent surgical anatomy and pathophysiology is essential toward developing an effective diagnostic and treatment strategy. A thorough clinical history and examination guide a comprehensive diagnostic evaluation that includes serial examinations, neurophysiologic testing, and imaging studies. Conservative treatment may provide symptomatic relief; however, surgical management involving revision neuroplasty, neurolysis, nerve reconstruction, and/or local soft-tissue flap augmentation may be indicated in refractory cases.

Ultrasound-Guided Microinvasive Carpal Tunnel Release Using a Novel Retractable Needle-Mounted Blade: A Cadaveric Study

Ultrasound (US)-guided microinvasive procedures are defined as those performed via needles without notable scarring. Ten cadaver hands underwent US-guided microinvasive carpal tunnel release using a novel needle-based tool, the micro i-Blade (Summit Medical Products, Inc, Sandy, UT). A US-imaged landmark, the inflexion point of the ligaments distal to the hook of the hamate, was used to position the distal extent of the cut. The transverse carpal ligament was successfully released in all hands without damage to nerves or arteries. In 3 specimens, the fascia between the thenar and hypothenar muscles was partly preserved, whereas the palmar aponeurosis was partly cut in 1 specimen. The micro i-Blade with the cutting knife retracted was also useful as a probe palpated through the palm of the cadaver hand, to test the release of the transverse carpal ligament and to guide the procedure.

Endoscopic carpal tunnel release: a 5-year experience

Background:

Endoscopic carpal tunnel release (ECTR) has gained recognition as an alternative to the current gold standard, the open carpal tunnel release (OCTR). Detailed technical points for the ECTR have not been explained in the literature, especially for surgeons who are considering trying this technique.

Objectives:

In this paper, we present our 5-year experience with the ECTR and special emphasis will be placed on less frequently discussed technical points, such as the optimal site to make the skin incision and the signs to look for in a completely divided retinaculum.

Patients and Methods:

In this prospective nonrandomized clinical trial, 176 patients with carpal tunnel syndrome who underwent surgical operation using the Agee uni-portal endoscopic carpal tunnel release technique, over a period of 5 years, were included. The “Hand Questionnaire”, a standard questionnaire for hand surgery, was used to evaluate the patients at one, three, six and twelve month post-operative time points. Pain and scar tenderness were measured using the visual analog scale system. We propose the ‘most proximally present wrist crease’ for the skin incision and the ‘proximal to distal sequential division of the retinaculum’ as our methods of choice. Two signs, named ‘railroad’ and ‘drop in’, are proposed and these will be discussed in detail as hallmarks of complete retinaculum release.

Results:

Of the 176 patients who underwent the ECTR operation, 164 cases (93.2%) had no or very little pain at the one year postoperative visit, and nearly all of the patients reported no relapse of symptoms at the previously mentioned postoperative time points. Patient satisfaction and functional recovery was comparable to other published ECTR studies, and showed better short-term results of this technique over the OCTR. One deep seated infection, three cases of transient index finger paresthesia due to scope pressure on the median nerve, and one case of median nerve branch transection, were observed. Scar complications, including; tenderness, redness and pain, were significantly lower in the proximally placed incision in comparison with the distally placed incision (P < 0.005).

Conclusions:

The ‘most proximally present wrist crease’ and the ‘distal to proximal division of the retinaculum’ using the two signs of ‘railroad’ and ‘drop in’ to confirm a complete division of retinaculum are proposed techniques that should be considered in order to produce good outcomes in ECTR. The ‘railroad’ sign is the parallel standing of the retinaculum edges, and the ‘drop in’ sign is the dropping of the retinaculum edge into the scope denote a completely divided retinaculum.

Endoscopic carpal tunnel release

ECTR is an elegant minimally invasive operative treatment of CTS, providing a rapid rehabilitation without increasing the risk of complications. However, there is a significant learning curve and the cost of the operation is significantly higher than with conventional open technique. However, the faster rehabilitation and the probability of reducing sick leave may lead to ECTR being overall more cost-effective than open CTR.

Outcomes and cost-effectiveness of carpal tunnel injections using sonographic needle guidance

This randomized controlled study addressed whether sonographic needle guidance affected the outcomes of corticosteroid injection for symptomatic carpal tunnel syndrome. Seventy-seven symptomatic carpal tunnels were randomized to injection by either (1) conventional anatomic landmark palpation-guided injection or (2) sonographic image-guided injection, each using a two-step technique where 3 ml of 1% lidocaine was first injected to hydrodissect and hydrodisplace critical intra-carpal tunnel structures followed by injection with 80 mg of triamcinolone acetonide (2 ml). Baseline pain, procedural pain, pain at outcome (2 weeks and 6 months), responders, therapeutic duration, total cost, and cost per responder were determined. There were no complications in either treatment group. Relative to conventional anatomic landmark palpation-guided methods, sonographic guidance for injection of the carpal tunnel resulted in 77.1% reduction in injection pain (p<0.01), a 63.3% reduction in pain scores at outcome (p<0.014), 93.5% increase in the responder rate (p<0.001), 84.6% reduction in the non-responder rate (p<0.001), a 71.0% increase in therapeutic duration (p<0.001), and a 59.3% ($150) reduction in cost/responder/year for a hospital outpatient (p<0.001). However, despite improved outcomes, cost per patient per year was significantly increased for an outpatient in a physician's office and was neutral for a hospital outpatient. Sonographic needle guidance significantly improves the performance and clinical outcomes of injection of the carpal tunnel and is cost-effective for a hospital-based practice, but based on current reimbursements, it significantly increases overall costs for medical care delivered in a non-hospital-based physician practice.

Revision carpal tunnel surgery: a 10-year review of intraoperative findings and outcomes

PURPOSE

To evaluate intraoperative findings and outcomes of revision carpal tunnel release (CTR) and to identify predictors of pain outcomes.

METHODS

We performed a retrospective cohort study of all adult patients undergoing revision CTR between 2001 and 2012. Patients were classified according to whether they presented with persistent, recurrent, or new symptoms. We compared study groups by baseline characteristics, intraoperative findings, and outcomes (strength and pain). Within each group, we analyzed changes in postoperative pinch strength, grip strength, and pain from baseline. Predictors of postoperative average pain were examined using both multivariable linear regression analyses and univariable logistic regression to calculate odds ratios of worsened or no change in pain.

RESULTS

We performed revision CTR in 97 extremities (87 patients). Symptoms were classified as persistent in 42 hands, recurrent in 19, and new in 36. The recurrent group demonstrated more diabetes and a longer interval from primary CTR, and was less likely to present with pain. Incomplete release of the flexor retinaculum and scarring of the median nerve were common intraoperative findings over all. Nerve injury was more common in the new group. Postoperative pinch strength, grip strength, and pain significantly improved from baseline in all groups, apart from strength measures in the recurrent group. Persistent symptoms and more than 1 prior CTR had higher odds of not changing or worsening postoperative pain. Higher preoperative pain, use of pain medication, and workers' compensation were significant predictors of higher postoperative average pain.

CONCLUSIONS

Carpal tunnel release may not always be entirely successful. Most patients improve after revision CTR, but a methodical approach to diagnosis and adherence to safe surgical principles are likely to improve outcomes. Symptom classification, number of prior CTRs, baseline pain, pain medications, and workers' compensation status are important predictors of pain outcomes in this population.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.