Endoscopic carpal tunnel release: prospective assessment of 255 consecutive cases

Recurrent carpal tunnel syndrome: Evaluation and treatment of the possible causes

AIM

To investigate the causes of the recurrent carpal tunnel syndrome (CTS) and implemented surgical interventions.

METHODS

Four hundred and eighty-seven patients, who were diagnosed with CTS and underwent surgical intervention between October 2016 and September 2007, were evaluated in this retrospective study. The age, gender, physical evaluation findings, electrophysiological examination reports and implemented surgical treatment methods were analyzed.

RESULTS

Thirty-nine of the cases were operated due to recurrent CTS. Further examination of the patients with recurrent CTS revealed that ten cases had diabetic polyneuropathy, three cases had hypothyroidism, two cases had rheumatoid arthritis and one case had systemic amyloidosis. Postoperative electromyography confirmed the neuropathy was due to systemic diseases. The remaining 23 patients with recurrent CTS did not have any systemic disease and all of them had applied previously to another health center.

CONCLUSION

We concluded that the recurrence rates in CTS might be decreased with exploration and incision of the entire transverse ligament. Damage to the motor and sensory branches of the median nerve could be avoided with an incision on the ulnar side.

Outcomes of open and endoscopic carpal tunnel release: a meta-analysis

BACKGROUND

Currently, there are two genres of surgical treatment of carpal tunnel syndrome, open versus endoscopic. The goal of our study is to analyze published data by comparing outcomes of surgical treatment for carpal tunnel syndrome and determine if one approach is superior to the other (open versus endoscopic).

METHODS

A meta-analysis of retrospective series of Carpal tunnel release including >20 patients, with results measuring outcomes based on at least six of the following nine parameters (paresthesia relief, scar tenderness, two-point discrimination, thenar muscle weakness, Semmes-Weinstein/SW monofilament testing, return to work time, grip and pinch strength, and complications).

RESULTS

Endoscopic carpal tunnel approach showed statistically superior outcomes in eight of the nine categories investigated. Only in the category of complications (mean occurrence of 1.2 % in the open release versus 2.2 % in the endoscopic release group) was the endoscopic group inferior.

CONCLUSION

This suggests that the endoscopic release is superior to the open release, particularly in experienced hands.

Diagnostic properties of nerve conduction tests in population-based carpal tunnel syndrome

BACKGROUND

Numerous nerve conduction tests are used for the electrodiagnosis of carpal tunnel syndrome (CTS), with a wide range of sensitivity and specificity reported for each test in clinical studies. The tests have not been assessed in population-based studies. Such information would be important when using electrodiagnosis in epidemiologic research. The purpose of this study was to compare the diagnostic accuracy of various nerve conduction tests in population-based CTS and determine the properties of the most accurate test.

METHODS

In a population-based study a questionnaire was mailed to a random sample of 3,000 persons. Of 2,466 responders, 262 symptomatic (numbness/tingling in the radial fingers) and 125 randomly selected asymptomatic responders underwent clinical and electrophysiologic examinations. A standardized hand diagram was administered to the symptomatic persons. At the clinical examination, the examining surgeon identified 94 symptomatic persons as having clinically certain CTS. Nerve conduction tests were then performed on the symptomatic and the asymptomatic persons by blinded examiners. Analysis with receiver operating characteristic (ROC) curves was used to compare the diagnostic accuracy of the nerve conduction tests in distinguishing the persons with clinically certain CTS from the asymptomatic persons.

RESULTS

No difference was shown in the diagnostic accuracy of median nerve distal motor latency, digit-wrist sensory latency, wrist-palm sensory conduction velocity, and wrist-palm/forearm sensory conduction velocity ratio (area under curve, 0.75-0.76). Median-ulnar digit-wrist sensory latency difference had a significantly higher diagnostic accuracy (area under curve, 0.80). Using the optimal cutoff value of 0.8 ms for abnormal sensory latency difference shown on the ROC curve the sensitivity was 70%, specificity 82%, positive predictive value 19% and negative predictive value 98%. Based on the clinical diagnosis among the symptomatic persons, the hand diagram (classified as classic/probable or possible/unlikely CTS) had high sensitivity but poor specificity.

CONCLUSIONS

Using the clinical diagnosis of CTS as the criterion standard, nerve conduction tests had moderate sensitivity and specificity and a low positive predictive value in population-based CTS. Measurement of median-ulnar sensory latency difference had the highest diagnostic accuracy. The performance of nerve conduction tests in population-based CTS does not necessarily apply to their performance in clinical settings.

Cost identification analysis for succinylcholine

The cost of a dose of succinylcholine from society's perspective equals the acquisition cost of the drug plus the cost of its adverse outcomes. We hypothesized that although the acquisition cost of succinylcholine is minimal, the true cost would be much larger. We reviewed the medical literature to identify the total cost of a dose of succinylcholine when administered for nonemergency purposes according to manufacturers' guidelines (i.e., to adults only). We found that 88% of the cost per dose of succinylcholine was for the chance of dying or sustaining permanent brain injury from anaphylactic or anaphylactoid reactions to succinylcholine. Consequently, the estimated cost per dose of succinylcholine was sensitive to the incidence of anaphylactic or anaphylactoid reactions to succinylcholine, the risk of severe injury from anaphylactic or anaphylactoid reactions, and the financial value of unforeseen instant death or permanent brain injury. The range for the cost per dose of succinylcholine was thus large, $9 to $93. Our best estimate of the cost per dose was $37. We conclude that the true cost per dose of succinylcholine from society's perspective is more than 20 times the acquisition cost. However, a precise costing requires better knowledge of the incidence and consequences of anaphylactic or anaphylactoid reactions to succinylcholine.

IMPLICATIONS

The true cost of succinylcholine is more than 20 times the acquisition cost of the drug. The estimated cost is very sensitive to the risk and cost of patients dying or sustaining brain injury from anaphylactic or anaphylactoid reactions to succinylcholine.

Contribution of magnetic resonance imaging for the diagnosis of median nerve lesion after endoscopic carpal tunnel release

Deterioration of pre-existing signs or appearance of a nerve deficit raise difficult problems during the complicated course following endoscopic carpal tunnel release. One possible explanation is transient aggravation of nerve compression by passage of the endoscopy material, but these signs may also be due to incomplete section of the flexor retinaculum or an iatrogenic nerve lesion. Each case raises the problem of surgical revision. The authors report three cases of open revision in which MRI allowed a very precise preoperative diagnosis of the lesions and all of the MR findings were confirmed during surgical revision. In the first case, MRI showed section of the most radial branches of the median nerve (collateral nerves of the thumb, index finger and radial collateral nerve of the middle finger). The proximal origin of the nerve of the 3rd web space, above the retinaculum, an anatomical variant, was also identified. Section of 2/3 of the nerve of the 3rd web space, proximal to the superficial palmar arch, was observed in the second case. Simple thickening of the nerve of the 3rd web space, without disruption after opening of the perineurium, was observed in the third case. MRI therefore appears to be an examination allowing early and precise definition of indications for surgical revision in this new iatrogenic disease.

The incidence of recurrence after endoscopic carpal tunnel release

Endoscopic carpal tunnel release has been used to decompress the median nerve in carpal tunnel syndrome for over the past decade, with an advantage (over the traditional "open" release) being decreased pain in the postoperative period. The goals of this study were to attempt to define the recurrence rate after endoscopic carpal tunnel release and to determine if it differs from that of open technique. The charts of 191 consecutive carpal tunnel syndrome patients treated operatively at the University of Missouri were reviewed. For this study, recurrent carpal tunnel syndrome was defined as documented cases in which the symptoms had resolved following surgical release but subsequently recurred, requiring surgical rerelease of the carpal tunnel. All endoscopic releases were performed using the Chow two-portal technique. Statistical analysis was performed using Fisher's exact test. A total of 103 patient hands had open carpal tunnel releases; 88 were endoscopically released. Total follow-up time (from the initial release) averaged 29 months for the open group and 22 months for the endoscopic group. There were no recurrences in the open group and six recurrences in the endoscopic group (7 percent, p = 0.008). All six recurrences were in worker's compensation patients. The median time between endoscopic release and rerelease was 8.5 months. There seems to be a statistically higher incidence of recurrence of carpal tunnel syndrome after endoscopic release compared with the traditional "open" release in our cases. Although the pathogenesis of this increased rate of recurrence is not clear, this should be considered when planning surgical release of the volar carpal ligament for carpal tunnel syndrome.

Multiple Entrapment Neuropathy in the Upper Extremity

Multiple entrapment neuropathy is compression of more than two nerves in the same extremity. In this case series, 169 patients (208 upper extremities) with this condition were identified, and 124 patients (138 upper extremities) had surgical decompression after an ineffective course of conservative treatment. There were 31 men and 93 women. Average age was 41 years (range 20-87 years). Follow-up averaged 23 months (range 12 to 60 months). Our rating system included patients' self-assessment of overall symptom improvement and return to activity and a physician assessment of strength (grip and pinch) and sensibility (recovery of two-point discrimination). A total of 92 patients (67%) achieved good to excellent results. The clinical features of multiple entrapment neuropathy in our series were presented with a variety of nerve compression syndromes and with a high incidence of regional musculotendinous syndromes. In our surgical treatment, we emphasise simultaneous release of all possible compression sites with a minimally invasive endoscopic approach to achieve better results.

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.

Carpal tunnel topography during endoscopic decompression

The safety of the endoscopic technique for carpal tunnel release remains a major concern. Serious complications such as division nerves, tendons or vessels may occur. In this study the topography of the carpal tunnel was studied in fresh cadaver hands after the introduction of the blade assembly of a one portal system. By using a plastination method, it was possible to study the in situ relationships in detail by serial cross sections. Furthermore a modified Spalteholz method allowed the position of the blade to be viewed in whole specimens.

Self-administered outcome instrument in carpal tunnel syndrome. Reliability, validity and responsiveness evaluated in 102 patients

We evaluated a Swedish version of a self-administered disease-specific outcome questionnaire for carpal tunnel syndrome regarding reliability, validity and responsiveness to clinical change. It consists of multi-item scales assessing symptom severity, function, patient satisfaction and quality of life. It was given to 102 patients before and 3 months after carpal tunnel release. Test-retest reliability, studied in a subsample of 22 patients on two occasions with a 1-3-week interval, showed good agreement between the scores. Internal consistency of the scales was high (Cronbach alpha 0.80-0.95). Validity of the scales was evaluated using the SF-36 general health questionnaire in a subgroup of 48 patients as well as items concerning patient satisfaction, showing the expected relationships between these measures. Responsiveness of the scales to clinical change, estimated by the effect size and standardized response mean, was large (0.94-1.7). We conclude that this questionnaire can provide a standardized measure of symptom severity and functional status, as well as patient satisfaction and quality of life in the carpal tunnel syndrome.