Carpal tunnel release. A prospective, randomized assessment of open and endoscopic methods

Nerve fibre composition of the palmar cutaneous branch of the median nerve and clinical implications

Fifteen fresh human cadaver hands were dissected, using x2.8 loupe magnification, to study the subcutaneous innervation at the site of the incision (in the line with the radial border of the ring finger) for standard open carpal tunnel decompression. Subcutaneous nerve branches were detected and traced proximally to determine their origin. Morphometric analysis of nerve cross sections from the site of the incision and from the main nerve trunk proximal to cutaneous arborisation was performed using light and transmission electron microscopy and a computer-based image analysis system. At the site of the incision, the ulnar sub-branch (US) of the palmar cutaneous branch of the median nerve (PCBMN), which innervates the skin over the hypothenar eminence, was found in 10 of 15 cases. Branches from the ulnar side were not detected. The main trunk of PCBMN consisted on average of 1000 (SD 229) myelinated axons arranged in 1-4 fascicles. In the US of the PCBMN there were on average 620 (SD 220) myelinated axons, 80% of them smaller than 40 microm(2) i.e. thin myelinated axons, and on average 2037 (SD 1106) unmyelinated axons, arranged in 1-3 fascicles. The ratio of the number of myelinated axons in the US and the main trunk of the PCBMN was on average 63% (SD 19%). Frequency distribution of cross-sectional areas of myelinated axons shows no significant difference between the US and the main nerve trunk of the PCBMN. The importance of incision trauma to subcutaneous innervation of palmar triangle is emphasised and possible mechanisms of scar discomfort are discussed.

Biomechanical and anatomical consequences of carpal tunnel release

Carpal tunnel syndrome is an exceedingly common orthopaedic problem in the United States. When conservative management is unsuccessful, most surgeons proceed to surgical treatment. Though the carpal tunnel release procedure is usually curative, many patients experience postoperative complications, such as scar sensitivity, pillar pain, recurrent symptoms, and grip weakness, regardless of whether the release was done through an open, mini-open, or endoscopic approach. The exact causes of these and other complications of carpal tunnel release remain unclear. Release of the carpal tunnel has an effect on carpal anatomy and biomechanics, including an increase in carpal arch width, carpal tunnel volume, and changes in muscle and tendon mechanics. We set out to review the morphological and biomechanical changes caused by carpal tunnel release with the goal of better understanding the root causes of postoperative complications. This article first reviews normal carpal tunnel anatomy and anatomic variations, then available surgical techniques for carpal tunnel release, and finally the literature on morphologic, physiologic and biomechanical alterations in the wrist after carpal tunnel release.

Early outcome and cost-effectiveness of endoscopic versus open carpal tunnel release: a randomized prospective trial

Proponents of endoscopic carpal tunnel release have been advocating the technique for more than 10 years but there is still debate about its efficacy, safety and cost-effectiveness. We have performed a randomized, prospective, blind trial to compare early outcome after single portal endoscopic or open carpal tunnel surgery and to assess the cost-effectiveness of the procedures. There were no significant differences in symptom and functional activity scores, grip strength or anterior carpal pain in the first 3 months. For those in employment, we found a statistically significant difference between the two treatment groups with the endoscopic group returning to work, on average, 8 (95% CI, 2-13 days) days sooner than the open group. This translates into a cost saving to industry. There were no major neurovascular complications in either group. On the basis of these findings, we recommend that endoscopic carpal tunnel release should be considered in the employed as a cost-effective procedure, but perhaps not in the general population as a whole.

Results of 1245 endoscopic carpal tunnel decompressions

Between 1994 and 2000, the senior author performed 1245 endoscopic carpal tunnel decompressions. There were 291 bilateral cases. A telephone review was conducted of those patients who had not had an early excellent result, or conversion to an open procedure. Ninety-four per cent follow-up of patients in this group was achieved; 88% had an early excellent result with no subsequent problems. In 33 hands (3%) the carpal tunnel was opened, because of abnormal anatomy or poor view. A further 5% had a late excellent result. Seventeen hands (1%) have required subsequent open decompression, with adherence of the median nerve often found at revision surgery. Another 24 hands (2%) had a poor result. Fourteen hands (1%) had minor symptoms and 26 (2%) had another diagnosis of upper limb pathology. In contrast to other series, there was only one case of damage to an important structure - the radial digital nerve of the thumb.

A prospective study of outcome following mini-open carpal tunnel release

Mini-open carpal tunnel release has been the focus of recent attention for surgical decompression of carpal tunnel syndrome. Other techniques such as standard open carpal tunnel release and endoscopic release have been well established, and outcomes, complications and results for these operations have been published widely. Our study uses the validated Levine Katz questionnaire for carpal tunnel syndrome to measure patient subjective outcomes at one year follow-up after mini-open carpal tunnel release. Thirty-four consecutive hands were enrolled prospectively with preoperative and postoperative questionnaires. Mean symptom severity scores per question improved from 2.8 to 1.3 and mean function severity scores per question improved from 2.6 to 1.3. Comparing our data to the historical cohort of Levine et al., there was a statistically significant improvement in postoperative outcomes in our population (p < 0.0001).

Endoscopic versus open carpal tunnel release: a randomized trial

PURPOSE

This study compared the outcomes in patients assigned to either endoscopic carpal tunnel release (ECTR) or traditional open carpal tunnel release (OCTR).

METHODS

An unbalanced randomized clinical trial (91 endoscopic, 32 open) was conducted. Short-term and long-term outcomes were evaluated by a blinded assessor. The primary outcome measures were symptom severity measured on a self-report scale and nerve/vascular complications. Secondary outcomes included the McGill pain questionnaire, grip strength, pinch strength, sensory threshold (NK PSSD device, NK Biotechnical Corp, Minneapolis, MN), and time to return to work.

RESULTS

Both groups improved on all outcomes. No differences were observed in primary outcomes between the groups at either baseline or follow-up at 1 week, 6 weeks, or 12 weeks after surgery. No significant complications occurred in either group. Grip strength and pain were significantly better at 1 and 6 weeks in the endoscopic group although differences dissipated by 12 weeks. No significant differences occurred in other secondary outcomes. Long-term satisfaction was lower in the endoscopic group, attributable to a 5% rate of re-operation. Lower rates of endoscopic release have occurred at our center once these results were available to surgeons and patients.

CONCLUSIONS

No substantive difference in benefit was shown for these 2 methods of carpal tunnel release.

Tenoscopic release of the equine carpal canal

OBJECTIVE

To develop a tenoscopic method to divide the carpal flexor retinaculum and decompress the carpal canal.

STUDY DESIGN

Cadaver specimen study and prospective trial.

ANIMALS

Twelve cadaveric limbs, 4 clinically normal horses, and 2 clinically affected horses. Methods-A tenoscopic approach to the proximolateral aspect of the carpal sheath was used to identify and facilitate endoscopic division of the inner and outer layers of the carpal flexor retinaculum in cadaver limbs. The technique was further evaluated in 4 normal and 2 clinically affected horses.

RESULTS

Anatomic dissection, intraoperative observation, necropsy, histologic evaluation, and both short- and long-term clinical follow-up indicate that a tenoscopic approach that divides the inner layer of the carpal retinaculum can successfully decompress the equine carpal canal. No iatrogenic damage to surrounding structures was evident, division of the retinaculum was adequate and permanent, and clinical morbidity was negligible. Resolution of effusion was evident in both clinical cases of carpal canal syndrome and lameness resolved in the 1 horse in which long-term follow-up was possible.

CONCLUSIONS

Tenoscopic release of the carpal flexor retinaculum could provide a minimally invasive method to quickly, safely, and effectively decompress the carpal canal.

CLINICAL RELEVANCE

Tensocopic release of the carpal flexor retinaculum is a safe alternative to open division of the retinaculum to decompress the carpal canal in horses with carpal canal syndrome.

Compressive neuropathies of the upper extremity

Although any peripheral nerve may be compressed anywhere along its course, nerve compression syndromes typically occur at predictable sites with predictable clinical presentations. A detailed history and physical examination can establish a diagnosis, and electrodiagnostic studies and at times imaging can confirm it. Physicians should adopt a systematic approach of diagnosing and treating these types of nerve lesions. The physician and the patient can be rewarded with favorable outcomes.

Comparative responsiveness of the disabilities of the arm, shoulder, and hand, the carpal tunnel questionnaire, and the SF-36 to clinical change after carpal tunnel release

PURPOSE

The objective of this study was to compare the responsiveness (ability to accurately detect change) of 3 self-administered questionnaires to changes produced by carpal tunnel release.

METHOD

The Disabilities of the Arm, Shoulder and Hand (DASH), the Brigham and Women's Carpal Tunnel Questionnaire, and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) were completed by 34 subjects before surgery and at 6 and 12 weeks after carpal tunnel release.

RESULTS

The instrument most sensitive to clinical change at 12 weeks as judged by effect size and standardized response means was the Carpal Tunnel Questionnaire (effect size/standardized response means, 1.71/1.66) followed by the DASH (1.01/1.13) and the Medical Outcomes Study 36-Item Short-Form Health Survey bodily pain (0.57/0.52) and role physical (0.39/0.39) subscales. There was good correlation between DASH and Carpal Tunnel Questionnaire change scores (Spearman correlation coefficient 0.87).

CONCLUSIONS

The Carpal Tunnel Questionnaire is the most sensitive to clinical change, but the DASH is sufficiently responsive for use in outcome studies of carpal tunnel syndrome done 12 or more weeks after surgery.

R, Azze RJ. Comparative study between endoscopic technique by a proximal port and mini palmary incision in the surgical treatment of carpal tunnel syndrome

The authors present a prospective study comparing two surgical techniques for carpal tunnel release. A minimal - incision open decompression(3) is compared with an endoscopic release(2), that utilizes only a single proximal portal. There were operated on, 28 wrists in 28 patients, with clinical signs and EMG changes consistent on idiopathic carpal tunnel syndrome, that failed under previous conservative treatment. They were randomized into two groups , undertaken surgical treatment, either by endoscopic release or by open decompression. Grip strength (measured by dynamometric), sensitivity (measured by Semmes-Weinstein monofilaments), presence of pain and paresthesia, date of return to activities of daily living and complications were evaluated pre-operative and at 1, 2, 4, 6, 12 weeks after surgery. After 12 months average follow up, the results indicated that this proximal portal endoscopic technique can be safely performed, showing advantages over open conventional method, in terms of sooner return of grip strength, date of return to activities of daily living, and less incidence of pillar pain. No differences in paresthesia resolution, sensibility improvement or complications incidence were found.

Endoscopic carpal tunnel release: thirteen years' experience with the Chow technique

The purpose of this single-center study was to evaluate the results of endoscopic carpal tunnel release (ECTR) by using the dual portal Chow technique in a large series of patients. A total of 2,675 procedures in 1,886 patients were performed during a 13-year period. Follow-up evaluation was performed in 2,402 (90%) cases or 1,698 (90%) patients. The success rate was 95% and the recurrence rate was 0.5%. A total of 106 cases (4.5%) were considered failures or had unsatisfactory results. The overall complication rate was 1.1% but no serious complications occurred in this series. The return-to-work status was followed-up in 1,156 patients; 90% of non-worker's compensation patients and 60% of worker's compensation patients returned to work within 4 weeks. This study suggests that ECTR for carpal tunnel syndrome (CTR) is a reliable procedure with a high success rate. Based on our 13 years of experience, we believe that the technique is safe and iatrogenic complications can be avoided with meticulous surgical technique.

Surgical technique to reduce scar discomfort after carpal tunnel surgery

A total of 379 patients (416 hands) with clinically diagnosed and electromyographically confirmed carpal tunnel syndrome were enrolled in a prospective study to determine the influence of a modified open decompression technique on postoperative scar discomfort. The new technique used in 184 patients (200 hands) is presented. Special attention was focused on identification and preservation of macroscopically detectable subcutaneous nerves. After using this method, which permits complete visualization of the entire transverse carpal ligament, the incidence of postoperative scar discomfort was 2.5%. This was significantly lower compared with the group of 195 patients (216 hands) treated by standard open decompression technique, without preservation of subcutaneous nerves. Primary results regarding relieving symptoms were comparable in both groups. Five anatomic variations of subcutaneous innervation, at the site of the incision in the line with the radial border of the ring finger, are described. The etiology of scar discomfort is discussed.

Enabling meta-analysis in systematic reviews on carpal tunnel syndrome

Possible solutions to the problems of clinical heterogeneity of outcome measures and inadequate reporting of results for randomized controlled trials (RCTs) on carpal tunnel syndrome (CTS) are presented. Meta-analysis was impeded by these problems in 2 systematic reviews concerning conservative and surgical treatment options for CTS. A solution to the problem of inadequate data presentation is to add explicit information on minimal requirements with regard to data presentation to guidelines for the reporting of studies. To resolve the problem of clinical heterogeneity of the outcomes there should be consensus on the (validated) outcomes that should be used in RCTs. For CTS there is little evidence available on the reliability, validity, and responsiveness to change of the commonly used outcomes in RCTs. Resolving both problems will increase the comparability of RCTs, enabling the calculation of a pooled estimate of effect in a meta-analysis.

Laminar configuration of the transverse carpal ligament

We investigated the laminar configuration of the transverse carpal ligament, using 77 hands from 44 donated cadavers. According to the running directions and attachments of the fiber bundles composing the ligament, we identified four basic bundle patterns: proximal transverse, distal transverse, radial oblique, and ulnar oblique. Although these patterns often coexisted and the bundles were somewhat intermingled, a specific pattern was very evident in several laminae. Laminae with the distal transverse bundle pattern were the thickest and were reinforced by additional fibers which originated from the palmar aponeurosis and were deeply inserted into the lamina. Based on the laminar configurations of the superficial and deep layers and their composite fiber bundles, we classified the ligaments into four types. Type I, in which distal transverse and ulnar oblique laminae predominated in every layer, was the most common (44.2%), while another large group (41.6%) exhibited type II ligaments, comprising distal transverse and ulnar oblique laminae in the superficial layer and proximal transverse and radial oblique laminae in the deep layer. Thus, in almost half of the patients (type II), the strong distal transverse lamina is likely to be excised during the final step of endoscopic carpal tunnel release because of its superficial localization. This could be a major reason for the frequent occurrence of incomplete release. Moreover, the almost universal superficial ulnar oblique bundle pattern (observed in type I, II, and III ligaments), predisposes to scarring, which may cause radial shifting of the ulnar neurovascular bundle and may affect the palmar branch of the median nerve. We conclude that the interindividual variability seen in the results of endoscopic carpal tunnel release, including minor complications, depends partly on configurational variations in the laminar arrangement of the transverse carpal ligament.

Surgical release of the carpal tunnel

A thorough understanding of the normal anatomy and possible anomalies that may exist is important for the surgeon managing median nerve compression at the wrist. Given the high incidence of anatomic variability occurring in and around the carpal canal, open decompression of the median nerve is the preferred surgical technique for treating carpal tunnel syndrome. This approach provides complete visualization of the region, enabling the surgeon to decompress the nerve thoroughly, identify and treat anatomic abnormalities, and protect important neurovascular structures. Open carpal tunnel release is a safe and reliable operation with a high rate of functional improvement and patient satisfaction.

Carpal tunnel release via limited palmar incision

The limited incision carpal tunnel release provides an effective, reliable, and safe method for decompression of the median nerve at the wrist. The technique described above minimizes risk of complication through the design of the instruments and conceptual approach to the anatomy and surgical exposure. This method combines the reduced postoperative pain and quicker recovery of the ECTR technique with the safety and lower operative expense of the conventional open technique.

Carpal tunnel release in the United States and Sweden: reimbursement patterns, cost for treatment, and return to work

Cost containment plays an increasingly important role in health care, affecting providers and recipients. The present investigation addressed a limited number of factors that relate to the total cost for surgical treatment of carpal tunnel syndrome. The purpose of this study was to compare socioeconomic factors in two different societies and how worker's compensation plays a role in the cost, rehabilitation, and operative practices. To that purpose, the authors studied hospital and insurance records from a total of 123 female patients treated in two tertiary referral centers (University of Pittsburgh, Pa., and University of Umea, Sweden). The 123 patients were referred to three subgroups. Group A comprised patients from the University of Pittsburgh with worker's compensation (n = 34), group B comprised patients from the University of Pittsburgh without worker's compensation (n = 47), and group C comprised patients from the University of Umea (n = 42). The analyzed data showed a tendency toward longer duration of postoperative sick leave for those with worker's compensation than those without worker's compensation for patients from the University of Pittsburgh. However, operating room times and operating times, operative cost, use of postoperative therapy, and duration for sick leave were substantially less for patients treated at the University of Umea. There was no statistically significant difference in time off work between group A and group B. The results may indicate that the effect of compensation on a patient's ability or willingness to recover after treatment for carpal tunnel syndrome may be less important than factors that do not primarily relate to the patient or the surgical procedure.

Variations in incisions and postoperative management in carpal tunnel surgery

This study examines the variations in incisions and postoperative protocol of open carpal tunnel release. A questionnaire was distributed to 65 hand surgeons. Respondents were asked to draw their preferred incision on original photocopies of the same palm. The results were measured against standard anatomical landmarks (thenar crease, vertical axis of the third web space, proximal palmar crease and the distal wrist crease). The participants were also asked to answer questions concerning their postoperative protocols. Demographics of the cohort, as well as the variations in incisions and postoperative management, were analyzed. Significant variations existed in the length and location of the incision in the palm. The differences in postoperative care in this cohort of surgeons were less significant.

Bilateral endoscopic carpal tunnel releases: Simultaneous versus staged operative intervention

PURPOSE

Open and endoscopic carpal tunnel release techniques have achieved excellent results for treatment of carpal tunnel syndrome. Symptoms frequently occur bilaterally but there are no reports of simultaneous operative intervention. The purpose of this study was to evaluate results in patients who underwent staged bilateral endoscopic carpal tunnel releases and in those who underwent simultaneous bilateral releases.

TYPE OF STUDY

Retrospective review.

METHODS

The efficacy of simultaneous and staged bilateral endoscopic carpal tunnel releases was evaluated using a retrospective chart review. This included patients who underwent these procedures during a 48-month period. Group A (48 patients) underwent staged procedures; group group B (48 patients) underwent simultaneous procedures. Inclusion criteria were a positive history and physical examination, positive electrical studies, and failure of conservative measures. Single-incision endoscopic releases were performed on an outpatient basis. Early rehabilitation with intermittent splinting was utilized. The analysis included complications, satisfaction, return to work, physician visits, physical therapy sessions, days to maximum medical improvement for all, and average percentage permanent partial impairment for Workers' Compensation patients.

RESULTS

A decrease in return to work at regular duty was noted in the simultaneous group compared with the staged group for patients who had not filed Workers' Compensation claims (P =.0158). The simultaneous group had fewer physician visits than the staged group (P =.0002). Overall patient satisfaction was equal.

CONCLUSIONS

Simultaneous bilateral endoscopic carpal tunnel releases are well tolerated with mild restrictions and a decrease in cost.

Postoperative nerve conduction changes after open and endoscopic carpal tunnel release

OBJECTIVE

To assess the improvement of motor distal latency (MDL), sensory nerve conduction velocity (SCV) of the median nerve and the amplitudes of compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) in patients with idiopathic carpal tunnel syndrome subjected to surgical treatment according to the open carpal tunnel release method and the endoscopic carpal tunnel release.

METHODS

Sixty-six hands of sixty-six patients were divided into two groups: the ECTR group and the OCTR group. The patients were evaluated preoperatively, and at 1, 3, 6, and 12 months postoperatively.

RESULTS

Although no statistically significant difference of the recovery of MDL and the amplitude of CMAP and SNAP was detected between the two groups at any time point during follow-up, one patient in the ECTR group in whom the operation had been converted to OCTR, showed delay of MDL and decrease in the amplitude of CMAP.

CONCLUSIONS

There is a risk of nerve damage in patients undergoing ECTR. Although statistical analysis suggests that nerve conduction improves by about the same degree 12 months after ECTR or OCTR, slightly faster improvement after OCTR cannot be excluded.

Systematic review of randomized clinical trials of surgical treatment for carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is a common disorder for which several surgical treatment options are available. However, there is no consensus on the most effective method of treatment. The object of this systematic review is to compare the efficacy of the various surgical techniques in relieving the symptoms of CTS and promoting return to work and/or activities of daily living.

METHODS

Computer-aided searches of Medline, EMBASE and the Cochrane Controlled Trials Register were conducted, together with reference checking. A rating system, based on the number of studies and their methodological quality and findings, was used to determine the strength of the available evidence for the efficacy of the treatment.

RESULTS

Fourteen studies were included in the review. None of the alternatives to standard open carpal tunnel release (OCTR) seems to offer better relief of symptoms. There is conflicting evidence about whether endoscopic carpal tunnel release results in earlier return to work and/or activities of daily living.

CONCLUSION

Standard OCTR is still the preferred method of treatment for CTS. It is just as effective as the alternatives, but is technically less demanding, so incurs a lower risk of complications and of added costs.

Risk of neurovascular injury with limited-open carpal tunnel release: defining the "safe-zone"

Limited-open carpal tunnel release was performed in ten cadaver arms using the "Safeguard" system. The "Safeguard" guide was intentionally placed off of the longitudinal middle/ring finger axis, either in 15 degrees of radial deviation or 15 degrees of ulnar deviation. Despite the errant placement, carpal tunnel release was performed without damage to any neurovascular structure. The proximity of neurovascular structures to the middle/ring finger axis was measured in all ten cadaver specimens. From this, a "safe-zone" was defined for endoscopic or limited-open carpal tunnel release. The "safe-zone" expands when surgery is performed from distal to proximal. The area of the "safe-zone" is greatest when a protective guide is placed between the bursal sac of the carpal canal and the flexor retinaculum.

[Anatomical study of the pre-retinacular fat pad of the wrist: application to a new surgical approach to the carpal tunnel]

INTRODUCTION

Decompression of the median nerve in the carpal tunnel by section of the flexor retinaculum is the generally accepted treatment for carpal tunnel syndrome and is usually effective in relieving the symptoms. Following postoperative observations we proposed the hypothesis that incisional pain following open carpal tunnel release could be partly explained by injury to the fat pad situated between the palmar carpal ligament and the flexor retinaculum.

METHOD

We performed an anatomical study on 20 fresh adult latex injected upper limbs.

RESULTS

The sus-retinacularis fat pad is a real anatomical structure, clearly delineated and located inside a defined fibrous space with its own innervation from the ulnar nerve. It lies in the path of the normal carpal tunnel approach.

DISCUSSION

Although most postoperative scar tenderness is attributed to neuroma formation because of injury to transverse branches of the palmar cutaneous nerves, we nevertheless consider that injury to the preretinacular fat pad also plays a part. We propose a modified approach to the carpal tunnel. This is a safe and simple method which respects the integrity of the sus-retinacularis fat pad so as to minimise the extent of scar tenderness.

Clinical study of surgical treatment of carpal tunnel syndrome: Open versus endoscopic technique

Twenty-six patients (30 hands) who underwent endoscopic carpal tunnel release were physically examined and asked to complete questionnaires on their symptoms, functional limitations and satisfaction. Their mean grip strength improved considerably from 17.5 kg before the operation to 31.3 kg at the final follow-up. Symptoms at the final follow-up were hypesthesia in 9 hands, muscle atrophy in 10, positive Tinel sign in 3, and positive Phalen sign in 1. The mean symptom severity score improved from 3.01 before the operation to 1.44 at the final follow-up and the mean functional status score improved from 3.20 to 1.54. The average times to return to activities of daily living and work were 7.3 days and 18.4 days respectively. Twenty-two of the 26 patients (85%) were satisfied. There was no injury to neurovascular structures. Arterial injuries were prevented by marking the superficial palmar arch and ulnar artery with a Doppler ultrasonic hemodrometer before surgery.

Carpal tunnel syndrome with severe sensory deficit: endoscopic release in 18 cases

Carpal tunnel syndrome (CTS) with severe sensory deficit was treated with endoscopic carpal tunnel release in 18 hands of 16 consecutive patients (median age 72 (28-92) years). In all hands, preoperative 2-point discrimination (2-PD) exceeded 15 mm in the radial and ulnar sides of the pulps of at least 2 of the 3 radial digits. All patients underwent an independent evaluation and answered a questionnaire concerning 11 activities of daily living (ADL) preoperatively and 6 months postoperatively. Complete resolution or improvement in daytime numbness and tingling was reported in 12 of 17 hands, of night symptoms in 12 of 16 hands, and of pain in 10 of 11 hands. The median ADL score improved from 3.1 to 1.4 (on a 1- to 5-point scale). 13 of the 16 patients were satisfied with the outcome. Two-PD had normalized in 14 hands and improved in 2. The results indicate that endoscopic carpal tunnel release is effective in improving symptoms and function in patients with CTS and severe sensory deficit, and that the prognosis for sensory recovery is good.

Surgical treatment of common entrapment neuropathies in the upper limbs

Entrapment neuropathies of the upper extremity are common, debilitating conditions. Most patients with these neuropathies are readily diagnosed on purely clinical grounds and may be effectively managed with nonoperative measures. However, the broad differential diagnosis often necessitates electrodiagnostic testing and radiographic imaging to clarify the situation. This review focuses on three of the most common entrapment neuropathies in the upper limbs: carpal tunnel syndrome (median nerve entrapment at the wrist), cubital tunnel syndrome (ulnar nerve entrapment at the elbow), and radial tunnel syndrome (posterior interosseous nerve entrapment). Anatomical considerations, patient evaluation, indications for surgical intervention, options for surgical approaches, outcomes, and complications are discussed.

[Neurolysis of the median nerve in the carpal canal using a mini-invasive approach. Apropos of a prospective series of 138 cases]

INTRODUCTION

The aim of this study was to assess the results of a prospective study of 138 cases with carpal tunnel syndrome operated on by a percutaneous technique.

METHOD

One hundred and twenty-nine patients (108 women and 21 men, with a mean age of 49.9 years) underwent preoperative assessment via a questionnaire and a clinical examination (the Weber test, buckle test, Kapandji test, Tinel test, Phalen test, Vainio test and grip force assessment). The surgical technique was singularised by the insertion of a probe cannula in the carpal tunnel so that the blade could be guided during annular ligament section.

RESULTS

The results were assessed at one, three and six months follow-up: 98.5% very good and good results were obtained (Kelly criteria); two patients presented with an algodystrophic syndrome. No vascular, tendinous or neurological complications were noted, and the procedure was in no instance switched to an open technique.

DISCUSSION

The main advantages of this technique are a rapid recuperation of hand function, with an average of 22.6 days off work, a low complication rate, and simple equipment.

Neurologic disorders masquerading as carpal tunnel syndrome: 12 cases of failed carpal tunnel release

We describe 12 patients with a diagnosis of carpal tunnel syndrome in whom carpal tunnel release was unsuccessful and another neurologic disorder was diagnosed subsequently. Final diagnoses included polyneuropathy, radiculopathy, motor neuron disease, spondylotic myelopathy, syringomyelia, and multiple sclerosis. Sources of error by the electromyographer and treating physician were identified. Care must be taken to avoid an inappropriate carpal tunnel operation when clinical or electrodiagnostic features are atypical.

Upper extremity disorders in women

Carpal tunnel syndrome, Colles' fracture, and osteoarthritis of the basilar joint of the thumb are only three of the many upper extremity conditions that preferentially affect women. With more and more women entering the workplace, these conditions become more disruptive of patients' lifestyles and even may be increasing in incidence. Orthopaedic surgeons traditionally have focused on the surgical treatment of patients with these conditions, but it is becoming increasingly clear that surgeons also must focus on delineating pathophysiology to better identify those individuals at risk and help prevent these potentially disabling disorders.

Carpal tunnel release by the Agee endoscopic technique. Results at 4 year follow-up

Ninety-five hands (86 patients) were treated by endoscopic carpal tunnel release using the technique of Agee. They were the first ones operated on by the senior author (GF) using this technique. The patients were interviewed at a mean follow-up of 4.5 years: 72% of hands were free of symptoms and 94% were described by the patients as functionally normal. Seventeen hands (out of 27) with residual or recurrent symptoms were examined. Nine hands (nine patients) were only partially improved (mean 6.7 on a 10 point scale) and in eight hands (seven patients), some symptoms had recurred after a mean delay of 3.8 years. It was possible to find a second pathology in most of these cases. It is necessary to inform the patient before operation that incomplete relief or recurrence of symptoms can occur after endoscopic carpal tunnel release, as with conventional release.

Open versus endoscopic carpal tunnel release: a decision analysis

The endoscopic technique for the surgical treatment of carpal tunnel syndrome was developed to decrease postoperative morbidity and accelerate a patient's return to normal activities and work. We used the methods of decision analysis to compare the total cost of the open versus the endoscopic technique. We adopted a societal perspective and included estimates of the costs of medical procedures and complications, as well as lost wages. Our base case analysis showed that the 2 techniques have similar total costs, given the assumptions of our model. The endoscopic approach is more costly if the complication rate of endoscopic surgery exceeds 6.2% (base case estimate, 5.0%). The endoscopic technique is more costly if the risk of career ending injury exceeds 0.001 (base case estimate, 0.0004) and if the average work absence following a complication exceeds 15.5 months (base case estimate, 12 months). In addition, the endoscopic technique is more costly if the difference between the 2 techniques in mean time to return to work is less than 21 days (base case estimate, 26 days). These findings have different implications for recipients and non-recipients of workers' compensation. If endoscopically treated patients return to work an average of 42 days faster than patients treated with the open technique (24 days vs 66 days), as was documented for non-recipients of workers' compensation in one large study, the endoscopic strategy would be less costly ($5,599 for endoscopic release vs $7,340 for open surgery). If endoscopically treated patients return to work an average of just 10 days sooner (103 days vs 113 days), however, as was documented for workers' compensation recipients in the same study, the open technique would be less costly ($11,353 for open release vs $11,959 for the endoscopic technique). The relative costs are not sensitive to the direct medical costs of complications. These findings allow prediction of the costs of endoscopic and open surgery under a range of assumptions concerning key parameters. The analyses also emphasize the need for more precise data on risks and costs of surgical treatments for carpal tunnel syndrome.

Nerve entrapments of the upper extremity: A surgical perspective

The surgeon's perspective of nerve entrapment lesions in the upper extremity is discussed in this article. The focus is on the most common lesions of the median, ulnar, and radial nerves. An understanding of the anatomy and the potential pathologies provide the basis for surgical treatment. Current treatment protocols are discussed with the authors' recommendations that are based upon experience and literature review.

Cubital Tunnel Syndrome – Endoscopic-Assisted Anterior Submuscular Transposition of the Ulnar Nerve: A Feasibility Study Using a Cadaver Model

The purpose of this project was to perform endoscopic-assisted release of the ulnar nerve with submuscular transposition using a single 4 cm incision at the cubital tunnel level in fresh cadaver limbs. A successful cubital tunnel release decompression depends on the precise release of all potential entrapment points. Twelve fresh cadaver limbs (from six human cadavers) were used for this project. A 4 cm incision was made along the course of the ulnar nerve at the cubital tunnel. While the ulnar nerve was under constant magnified visualization and protection, all surrounding fascial tissues were released freely from the nerve. The medial intermuscular septum and arcade of Struthers were adequately visualized and divided. The overlying superficial fascia of flexor carpi ulnaris being dissected freely from the nerve, the nerve was transposed and repair of the flexor aponeurosis to the medial epicondyle was completed. Release of the ulnar nerve with submuscular transposition was accessible through one small skin incision with the aid of the endoscope. This new procedure may have clinical applications with a surgical outcome similar to the traditional approach. This technique prevents long scarring, decreases patient postoperative pain and shortens the rehabilitation period.

Failed endoscopic carpal tunnel release. Operative findings and results of open revision surgery

From 1994 to 1997, 22 patients (24 wrists) underwent open revision carpal tunnel release for persistent carpal tunnel syndrome after a primary endoscopic release. The age range was from 21 to 77 years. At the time of revision surgery, 22 wrists had an incomplete release of the flexor retinaculum and two patients had median nerve transection (one partial and one complete). One patient had release of Guyon's canal and not the carpal tunnel. After the open revision carpal tunnel release, 20 patients returned to work with five patients returning to jobs of lighter duty. In addition, these 20 patients had significant improvement in symptoms. The remaining two patients had sustained a median nerve injury and did not return to work. One of these patients developed a painful neuroma in continuity of the median nerve which required vein wrapping with a saphenous vein graft. This study indicates that endoscopic release of the flexor retinaculum holds the same risks and complications as open release. Based on our study we believe that patients with persistent carpal tunnel syndrome after failed endoscopic flexor retinaculum release can be successfully treated with open release.

Electromyographic evaluation after endoscopic carpal tunnel release in idiopathic carpal tunnel syndrome

The purpose of this study was to electromyographically evaluate results in patients with carpal tunnel syndrome (CTS) who underwent endoscopic carpal tunnel release (ECTR). The subjects were 26 patients with idiopathic CTS (37 hands) who were followed for at least 6 months after ECTR. To compare results informatively, hands were classified into four groups: those with normal distal motor latency (DML) and sensory conduction velocity (SCV) were classified as group A, those with normal DML and abnormal SCV as group B, those with an abnormal DML and normal SCV as group C, and those with abnormal DML and SCV as group D. All but one of the hands were classified as group D on the basis of preoperative electromyographic evaluation, while one was classified as group C. The mean preoperative obtainable DML and SCV values were 7.2 m and 27.3 m/s, respectively. Postoperatively, 12 hands were in group A, 8 hands in group B, 2 hands in group C, and 15 hands in group D. The mean DML and SCV values at final follow-up were 4.3 ms and 40.8 m/s, respectively. Of the 25 hands with muscle atrophy before surgery, 6 hands were in group A, 5 hands were in group B, 1 hand was in group C, and 13 hands were in group D at final follow-up. Thenar muscle atrophy and denervation potentials were present before surgery in 13 of the 15 hands classified as group D at the final follow-up.

Complications of endoscopic and open carpal tunnel release

Separate questionnaires regarding surgically treated complications of endoscopic and open carpal tunnel release over a 5-year period were sent to members of the American Society for Surgery of the Hand to assess and compare major complications of the 2 procedures. Four hundred fifty-five major complications from endoscopic carpal tunnel release were treated by the 708 respondents. This included 100 median nerve lacerations, 88 ulnar nerve lacerations, 77 digital nerve lacerations, 121 vessel lacerations, and 69 tendon lacerations. There were 283 major complications from open carpal tunnel release treated by 616 respondents, including 147 median nerve lacerations, 29 ulnar nerve lacerations, 54 digital nerve lacerations, 34 vessel lacerations, and 19 tendon lacerations. Although this is a retrospective voluntary study with resultant methodologic flaws, the data support the conclusion that carpal tunnel release, be it endoscopic or open, is not a safe and simple procedure. Major, if not devastating, complications can and do occur with both procedures, of which surgeons should be ever cautious.

Endoscopic carpal tunnel release: a prospective analysis of factors associated with unsatisfactory results

The first 100 consecutive cases of endoscopic carpal tunnel release (ECTR) performed by the author were studied prospectively during 6 to 24 months follow-up. Various preoperative and postoperative factors were subjected to statistical analysis to determine possible associations with unsatisfactory results. Overall, 92% of hands had a satisfactory result from ECTR, although not all were rendered symptom-free. There were no significant complications. Preoperative factors associated with an increased likelihood of unsatisfactory results included hands with preoperative weakness, widened two-point discrimination, myofascial pain syndrome or fibromyalgia, involvement in litigation, multiple compressive neuropathies, or the presence of abnormal psychological factors. A trend to less satisfactory results was present in Workers' Compensation cases and patients with normal motor latencies on nerve conduction studies. Multiple postoperative factors correlated with unsatisfactory results.

Clinical management of carpal tunnel syndrome: a 12-year review of outcomes

Carpal tunnel syndrome (CTS) is a disorder frequently encountered by occupational health care specialists. The health care management of this disorder has involved a diverse set of clinical procedures. The present article is a review of the literature related to CTS with an emphasis on occupational-related CTS. MEDLINE, Cumulative Index to Nursing and Allied Health Literature, PsycLIT, and NIOSHTIC databases from 1985-1997 were searched for treatment outcome studies related to CTS. Treatments of interest included surgery, physical therapy, drug therapy, chiropractic treatment, biobehavioral interventions, and occupational rehabilitation. A systematic review of the effects of these interventions on symptoms, medical status, function, return to work, psychological well-being, and patient satisfaction was completed. Compared to other treatments, the majority of studies assessed the effects of surgical interventions. Endoscopic release was associated with higher levels of physical functioning and fewer days to return to work when compared to open release. Limited evidence indicated: 1) steroid injections and oral use of B6 were associated with pain reduction; 2) in comparison to splinting, range of motion exercises appeared to be associated with less pain and fewer days to return to work; 3) cognitive behavior therapy yielded reductions in pain, anxiety, and depression; and, 4) multidisciplinary occupational rehabilitation was associated with a higher percentage of chronic cases returning to work than usual care. Workers' compensation status was associated with increased time to return to work following surgery. Conclusions are preliminary due to the small number of well-controlled studies, variability in duration of symptoms and disability, and the broad range of reported outcome measures. While there are several opinions regarding effective treatment, there is very little scientific support for the range of options currently used in practice. Despite the emerging evidence of the multivariate nature of CTS, the majority of outcome studies have focused on single interventions directed at individual etiological factors or symptoms and functional limitations secondary to CTS.

Anthropometry and endoscopic carpal tunnel release

A prospective study was performed in 100 consecutive endoscopic carpal tunnel releases (ECTR) to assess the effect of a number of anthropometric measures on the ease of introduction of the ECTR system into the carpal tunnel. Ease of access to the carpal tunnel correlated with the wrist circumference, height and age of patients. Surgeons should be aware that ECTR is likely to be more difficult in small patients with small wrists and should have a higher threshold for conversion to the open technique to avoid neurological complications.

Does endoscopic carpal tunnel release have a higher rate of complications than open carpal tunnel release? An analysis of published series

The purpose of this study was to evaluate the reported rate of complications after endoscopic carpal tunnel release by means of an analysis of 54 publications, reporting a total of 9516 endoscopic and 1203 open releases. Endoscopic release was comparable to open release in the rate of irreversible nerve damage (0.3% and 0.2% respectively) but case reports may indicate a small risk of unacceptable complications with endoscopy, such as transection of the median nerve. Reversible nerve problems were more common after endoscopic release. Tendon lesions were extremely rare (0.03%) and the rate of other complications (reflex sympathetic dystrophy, haematoma, wound problems, etc.) was about the same with endoscopic as with open release.

Effect of keyboard keyswitch design on hand pain

This randomized clinical trial evaluated the effects of keyboard keyswitch design on computer users with hand paresthesias. Twenty computer users were matched and randomly assigned to keyboard A (n = 10) or B (n = 10). The keyboards were of conventional layout and differed in keyswitch design. Various outcome measures were assessed during the 12 weeks of use. Subjects assigned keyboard A experienced a decrease in hand pain between weeks 6 and 12 when compared with keyboard B subjects (P = 0.05) and demonstrated an improvement in the Phalen test time (right hand, P = 0.006; left hand, P = 0.06). Keyboard assignment had no significant effect on change in hand function or median nerve latency. We conclude that use of keyboard A for 12 weeks led to a reduction in hand pain and an improved physical examination finding when compared with keyboard B. There was no corresponding improvement in hand function or median nerve latency.

Persistent or recurrent carpal tunnel syndrome following prior endoscopic carpal tunnel release

A retrospective review of patients with carpal tunnel syndrome (CTS) identified 20 patients (26 wrists) who had persistent or recurrent CTS after having undergone endoscopic carpal tunnel release (ECTR). Seven wrists never had relief of the original CTS symptoms; for the remaining 19 wrists, the average time to recurrence of CTS following ECTR was 4.8 months. All cases recurred within 12 months from the ECTR. All but 1 patient reported nocturnal pain. All patients experienced morning numbness and stiffness. All wrists had positive Phalen's test results. Once diagnosed with persistent or recurrent CTS, each of the wrists underwent open carpal tunnel release (OCTR). Twenty-two wrists were available for follow-up, with all patients reporting greater satisfaction and relief after the OCTR compared with the ECTR. It is important to recognize that CTS may persist or recur after ECTR. These patients should be treated with OCTR to provide symptomatic relief and prevent the sequelae of ongoing CTS.

Identification and preservation of Palmar cutaneous nerves during open carpal tunnel release

We looked for crossing cutaneous nerve branches during standard open carpal tunnel release and attempted to preserve them. Open carpal tunnel release was performed on 34 hands in 29 patients. Crossing cutaneous nerves were identified in 47% of hands and successfully preserved in each case. No patient experienced postoperative pillar pain or scar hypersensitivity.