In search of complications in carpal tunnel decompression

What Is the Infection Rate of Carpal Tunnel Syndrome and Trigger Finger Release Performed Under Wide-Awake Anesthesia?

BACKGROUND

High infection rates have been reported in hand procedures using the wide-awake local anesthesia no tourniquet (WALANT) method, causing some to question the validity of this approach. However, little evidence exists surrounding the direct use of WALANT compared with monitored anesthetic care (MAC). This study was conducted to directly compare the postoperative infection rates of carpal tunnel syndrome (CTS) and trigger finger (TF) release surgeries performed under WALANT and MAC.

METHODS

A retrospective study comparing postoperative infection rates between patients undergoing CTS and TR releases was conducted. Our primary outcome measure was postoperative infection. Our secondary outcome was postoperative complications. Comparative statistics were used to compare means of infection between the groups.

RESULTS

A total of 526 patients underwent CTS release (255 with WALANT and 271 with MAC), and 129 patients underwent TF release (64 with WALANT and 65 with MAC). Patients undergoing WALANT and MAC were statistically comparable in terms of sex, smoking status, diabetes, and American Society of Anesthesiologists physical status classification. In patients undergoing CTS release, there were no infections with WALANT and 6 infections (2.2%) with MAC. In patients undergoing TF release, there were no infections in either group. There were similar rates of complications in patients undergoing WALANT and MAC for CTS and TF releases.

CONCLUSION

There was no increased risk of infection with WALANT compared with MAC in CTS or TR surgeries. These surgeries can be safely conducted with lidocaine and epinephrine without a concern for increased risk of infections or complications.

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.

Surgery of True Recurring Median Carpal Tunnel Syndrome with Synovial Flap by Wulle Plus Integument Enlargement Leads to a High Patient's Satisfaction and Improved Functionality

This prospective study was conducted to investigate electrophysiological qualities and patient’s satisfaction of a synovial gliding tissue flap in treating true recurring carpal tunnel syndrome. In 14 patients (11 women, three men), 15 median nerves were included in this retrospective study. For all 15 nerves, motor and sensory nerve conduction velocity, compound muscle action potential, a Visual Analogue Scale-score (VAS-score) questionnaire and an adapted Levine-Test were evaluated pre- and postoperatively. All participants underwent operative neurolysis of the median nerve, which was then enwrapped by a synovial gliding tissue flap. Eleven procedures were completed by integument enlargement. Follow-up period was 12 months. Postoperatively, distal latency decreased significantly by 15.6%. Compound muscle action potential and sensory nerve conduction velocity did not improve significantly. VAS score regarding pain reduced highly significantly with 74.1%. The adapted Levine-Test function score improved highly significantly with 39.2%. The synovial gliding tissue flap lead to an excellent patient’s satisfaction for treating true recurring carpal tunnel syndrome. Primary wound closure should be completed with integument enlargement if needed.

Ulnar Neuropathy due to Volar/Ulnar Displacement of the Flexor Tendons after Open Carpal Tunnel Release: Case Report

Ulnar nerve neuropathy is a rare complication following the carpal tunnel release. Above all, compression neuropathy is much rare. We report an acute ulnar nerve neuropathy following open carpal tunnel release due to the volar and ulnar displacement of the flexor tendons from the carpal tunnel and review the literature.

CARPAL TUNNEL RELEASE WITH A LIMITED PALMAR INCISION: CLINICAL RESULTS AND PILLAR PAIN AT 18 MONTHS FOLLOW-UP

Limited open carpal tunnel release was performed in 58 hands (44 patients) using a single 1.5 cm palmar incision according to the technique described by Lee and Strickland.1The patients were assessed at regular intervals after surgery for hand functions and subjective symptoms, in particular pillar pain. There was rapid wound recovery with minimal post-operative pain and scarring, and return to functional activities within four weeks. At an average follow-up of 18 months (range 14–24 months), 91% of patients had complete or significant resolution of hand paraesthesia. No patient required further surgery. However, pillar pain was found in 48% of hands at four weeks, 21% at 12 weeks, 12% at six months, 9% at 12 months and 7% at the last follow-up. The significance of the incidence of pillar pain is discussed.

The cadaveric anatomy of the distal radius: implications for the use of volar plates

INTRODUCTION

Fractures of the distal radius are common upper limb injuries, representing a substantial proportion of the trauma workload in orthopaedic units. With ever increasing advancements in implant technology, operative intervention is becoming more frequent. As growing numbers of surgeons are performing operative fixation of distal radial fractures, an accurate understanding of the relevant surgical anatomy is paramount. The flexor carpi radialis (FCR) tendon forms the cornerstone of the Henry approach to the volar cortex of the distal radius. A number of key neurovascular structures around the wrist are potentially at risk during this approach, especially when the FCR is mobilised and placed under retractors.

METHODS

In order to clarify the safe margins of the FCR approach, ten fresh frozen human cadaver limbs were dissected. The location of the radial artery, the median nerve, the palmar cutaneous branch of the median nerve and the superficial branch nerve were measured with respect to the FCR tendon. Measurements were taken on a centre-to-centre basis in the coronal plane at the watershed level. In addition, the distances between the tendons of brachioradialis, abductor pollicis longus and flexor pollicis longus, and the radial artery and median nerve were measured to create a complete picture of the anatomy of the FCR approach to the distal radius.

RESULTS

The structure most at risk was the palmar cutaneous branch of the median nerve. It was located on average 3.4mm from the FCR tendon. The radial artery and the main trunk of the median nerve were located 7.8mm and 8.9mm from the tendon. The superficial branch of the radial nerve was 24.4mm from the FCR tendon and 11.1mm from the brachioradialis tendon.

CONCLUSIONS

Operative intervention is not without complication. We believe a more accurate understanding of the surgical anatomy is key to the prevention of neurovascular damage arising from the surgical management of distal radial fractures.

ENDOSCOPIC CARPAL TUNNEL RELEASE AND CONGENITAL ANOMALIES OF THE MEDIAN NERVE

Endoscopic release has been shown to be a safe and effective means of carpal tunnel decompression. The surgeon needs to be aware of the variations in the anatomy of the median nerve in order to minimise the risk of nerve injury. In this series of 748 endoscopic carpal tunnel releases, six were found to have variations in the median nerve anatomy, in two patients conversion to open release was necessary.

Clinical quality measures for intraoperative and perioperative management in carpal tunnel surgery

BACKGROUND

Previous research documents suboptimal preoperative or postoperative care for patients undergoing surgery. However, few existing quality measures directly address the fundamental element of surgical care: intra-operative care processes. This study sought to develop quality measures for intraoperative, preoperative, and postoperative care for carpal tunnel surgery, a common operation in the USA.

METHODS

We applied a variation of the well-established RAND/UCLA Appropriateness Method. Adherence to measures developed using this method has been associated with improved patient outcomes in several studies. Hand surgeons and quality measurement experts developed draft measures using guidelines and literature. Subsequently, in a two-round modified-Delphi process, a multidisciplinary panel of 11 national experts in carpal tunnel syndrome (including six surgeons) reviewed structured summaries of the evidence and rated the measures for validity (association with improved patient outcomes) and feasibility (ability to be assessed using medical records).

RESULTS

Of 25 draft measures, panelists judged 22 (88%) to be valid and feasible. Nine intraoperative measures addressed the location and extent of surgical dissection, release after wrist trauma, endoscopic release, and four procedures sometimes performed during carpal tunnel surgery. Eleven measures covered preoperative and postoperative evaluation and management.

CONCLUSIONS

We have developed several measures that experts, including surgeons, believe to reflect the quality of care processes occurring during carpal tunnel surgery and be assessable using medical records. Although quality measures like these cannot assess a surgeon's skill in handling the instruments, they can assess many important aspects of intraoperative care. Intraoperative measures should be developed for other procedures.

Does wrist immobilization following open carpal tunnel release improve functional outcome? A literature review

Carpal Tunnel Syndrome (CTS) is a compressive neuropathy of the median nerve in the carpal tunnel. It is the most common peripheral entrapment neuropathy. The surgical management includes dividing the flexor retinaculum to decompress the median nerve. Post-operative mobilization of the wrist is controversial. Some surgeons splint the wrist for 2-4 weeks whilst others encourage early mobilization. The literature has been inconclusive as to which method is most beneficial. The purpose of this study is to review the literature regarding the effectiveness of wrist immobilization following open carpal tunnel decompression. We reviewed all published clinical trials claiming to evaluate the mobility status following open carpal tunnel release. Studies not in the English language as well as those with small number of patients (n < 30) were excluded. There were five studies that fulfilled the eligibility criteria and were included in this review. We conclude that there is no beneficial effect from post-operative immobilization after open carpal tunnel decompression when compared to early mobilization.

Management of distal traumatic median nerve painful neuromas and of recurrent carpal tunnel syndrome: hypothenar fat pad flap

The hypothenar fat pad flap receives segmental blood supply from the ulnar artery in Guyon's canal. It is easy to elevate and mobilize and can provide protective covering and a gliding surface for the median nerve during secondary nerve surgery in the distal forearm and carpal tunnel. It is locally available and can be used without making additional surgical incisions.

Rate of infection after carpal tunnel release surgery and effect of antibiotic prophylaxis

PURPOSE

To determine the rate of postoperative wound infection and the association with prophylactic antibiotic use in uncomplicated carpal tunnel release surgery.

METHODS

We performed a multicenter, retrospective review of all the carpal tunnel release procedures performed between January 1, 2005, and August 30, 2007. Data reviewed included the use of prophylactic antibiotics, diabetic status, and the occurrence of postoperative wound infection. We determined the overall antibiotic usage rate and analyzed the correlation between antibiotic use and the development of postoperative wound infection.

RESULTS

The rate of surgical site infections in the 3003 patients who underwent carpal tunnel release surgery (group A) was 11. Antibiotic usage data were available for 2336 patients (group B). Six patients without prophylactic antibiotics had infection, as did 5 patients with prophylactic antibiotics. This difference was not statistically significant. Of the 11 surgical site infections, 4 were deep (organ/space) and 7 superficial (incisional). The number of patients with diabetes in the overall study population was 546, 3 of whom had infections. This was not statistically different from the nondiabetic population infection rate (8 patients).

CONCLUSIONS

The overall infection rate after carpal tunnel release surgery is low. In addition, the deep (organ/space) infection rate is much lower than previously reported. Antibiotic use did not decrease the risk of infection in this study population, including patients with diabetes. The routine use of antibiotic prophylaxis in carpal tunnel release surgery is not indicated. Surgeons should carefully consider the risks and benefits of routinely using prophylactic antibiotics in carpal tunnel release surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Anomalous palmar cutaneous branch of the median nerve in the distal forearm: case report

Variations exist in the anatomy of the palmar cutaneous branch of the median nerve about the wrist. We report an anatomic variation in the course of the palmar cutaneous branch of the median nerve identified in a 17-year-old girl undergoing surgery for a scaphoid nonunion. Instead of coursing ulnar to the flexor carpi radialis tendon, deep to the antebrachial fascia between the tendons of the flexor carpi radialis and palmaris longus, the palmar cutaneous branch of the median nerve was noted to cross volar to the distal aspect of the flexor carpi radialis to lie on its radial aspect. Knowledge of the anatomic variant described in this report should encourage surgeons to dissect carefully as they expose the flexor carpi radialis during the exposure of the distal radius or scaphoid.

Management of recurrent carpal tunnel syndrome with microneurolysis and the hypothenar fat pad flap

A retrospective chart review for the period between 1998 and 2006 was conducted to evaluate microneurolysis combined with a hypothenar fat pad flap (HTFPF) for patients at Mayo Clinic, Scottsdale, Arizona, who were being treated for recurrent carpal tunnel syndrome. After exclusion of patients with incomplete release of the transverse carpal ligament at the time of the original operation, 28 consecutive patients were identified. Their average age was 68.5 years (range 43-89 years). The average interval between the original carpal tunnel release and reexploration was 82 months (range 5-298 months). The average follow-up was 10.5 months (range 3-48.4 months). The preoperative two-point discrimination tests averaged 7 mm (range 5-12 mm). At surgery, all patients were found to have fibrosis surrounding the median nerve with adherence of the nerve to the radial leaf of the transverse carpal ligament. After surgery, the Tinel sign disappeared in 26 of 28 patients and two-point discrimination improved to an average of 6 mm (range 4-8 mm). Postoperative grip strength averaged 20 kg, compared with 11 kg preoperatively. Pain completely disappeared in 83% of patients (average improvement 93%, range 5-100%). Numbness completely disappeared in 42% of patients (average improvement 82.9%, range 5-100%). Tingling disappeared in 50% of patients (average improvement 84.7%, range 5-100%). No patient reported being worse after reoperation. These results suggest that the combination of microneurolysis and HTFPF can restore median nerve gliding and provide soft-tissue coverage, improving symptoms in patients with recurrent carpal tunnel syndrome.

Minimally invasive carpal tunnel decompression using the KnifeLight

OBJECTIVES

Carpal tunnel syndrome is a common condition causing hand pain, dysfunction, and paresthesia. Endoscopic carpal tunnel decompression offers many advantages compared with conventional open surgical decompression. However, it is equipment intensive and requires familiarity with endoscopic surgery. We review a minimally invasive technique to divide the flexor retinaculum by using a new instrument, the KnifeLight (Stryker, Kalamazoo, Michigan), which combines the advantages of the open and endoscopic methods, without the need for endoscopic set-up.

METHODS

Between July 2003 and April 2005, 44 consecutive patients (26 women [59%] and 18 men [36%]), with clinical signs and symptoms, as well as electrodiagnostic findings consistent with carpal tunnel syndrome, who did not respond to non-surgical treatment, underwent the new procedure. All patients were asked about scar hypertrophy, scar tenderness, and pillar pain. The Michigan Hand Outcomes Questionnaire (MHQ) was used to determine overall hand function, activities of daily living, work performance, pain, aesthetics, and satisfaction with hand function. Other preoperative testing included grip strength and lateral pinch strength. Grip strength was measured using the Jamar hand dynamometer (Asimov Engineering Co., Los Angeles, CA); lateral key pinch was measured using the Jamar hydraulic pinch gauge. Postoperative evaluations were scheduled at 2 weeks, 3 months, and 6 months after the procedure. A small 10-mm incision was made in the wrist crease and a small opening was made at the transverse carpal ligament. The KnifeLight tool was inserted, and the ligament was incised completely. Follow-up evaluations with use of quantitative measurements of grip strength, pinch strength, and hand dexterity were performed at 2 weeks, 3 months, and 6 months after surgery.

RESULTS

Fifty procedures were performed on 22 left hands (44%) and 28 right hands (56%). There were no complications related to the approach. All patients were able to use their hands immediately after the surgery. Scar tenderness and incisional pain were mild-to-moderate in the first 2 weeks, and these symptoms disappeared completely 6 months after surgery. Significant postoperative improvements in pain relief, patient satisfaction, hand function, daily activities, and work performance as assessed with the MHQ were noted at 3 and 6 months after surgery. Furthermore, significant improvement in patients' hand grip and pinch strength were observed 6 months after surgery. From a literature review, we found that the mean operation time of KnifeLight carpal tunnel release was the shortest compared with the conventional and endoscopic carpal tunnel release techniques. The median time needed for our patients to return to work was also the shortest among the different techniques.

CONCLUSION

Excellent functional outcomes and satisfaction were achieved using the KnifeLight for carpal tunnel decompression. Our minimally invasive method offers a quick, easy, and effective alternative to conventional or endoscopic carpal tunnel decompression.

Common Risk Factors Seen in Secondary Carpal Tunnel Surgery

BACKGROUND

We hypothesized that there are several common risk factors associated with secondary carpal tunnel releases. Therefore, we chose to investigate these common factors by analyzing the charts of those patients requiring a second carpal tunnel release (CTR) procedure.

METHODS

A retrospective chart review was performed, and patients were identified by searching hospital medical record databases using the Common Procedural Terminology.

RESULTS

Between January 1, 2000, and March 31, 2004, 2357 patients had a primary CTR, and 48 of them were found to have had a secondary CTR (of these 48, 9 had diabetes mellitus, 11 had hypertension, and 6 had gastrointestinal-related illnesses). Seven percent of those who had an open release primarily required a second CTR, while only 0.2% of those who had an endoscopic release primarily required a second CTR.

CONCLUSION

A greater number of secondary CTR procedures were required for those patients with symptoms of carpal tunnel syndrome in the group that had an open release primarily versus those that had an endoscopic release primarily. Diabetes mellitus and hypertension may also contribute to the need for secondary surgery.

Delayed ulnar neuropathy at the wrist following open carpal tunnel release

Open carpal tunnel release is a common and successful treatment of median neuropathy at the wrist (carpal tunnel syndrome). We report a case of delayed ulnar neuropathy at the wrist with onset 2 months after open carpal tunnel release. Clinical findings, electrophysiological studies, magnetic resonance imaging, and surgical exploration demonstrated ulnar nerve compression at Guyon's canal resulting from translocation of the carpal tunnel contents. To our knowledge, this is an unreported complication of open carpal tunnel release that merits wide appreciation.

Neural anatomy of the transverse carpal ligament

Carpal tunnel syndrome is one of the most commonly diagnosed disorders of the upper extremity. The etiology of the neuropathy is known to be associated with many disorders, with the etiology of carpal tunnel syndrome mainly attributable to ischemia of the median nerve. The purpose of this study was to determine the presence of neural elements within the transverse carpal ligament. Fourteen transverse carpal ligaments were harvested from seven male and seven female fresh frozen cadavers with an average age of 76 years. The tissues were stained with S-100 using a standard immunoperoxidase technique used to localize neural tissue. The transverse carpal ligament consisted of interwoven bundles of fibrous connective tissue. It was found to have an intraligamentous and extraligamentous neural network consisting mostly of free nerve endings and pacinian corpuscles. Ruffini's corpuscles were not identified. This study showed that there is neural innervation to the transverse carpal ligament. Pacinian corpuscles have been shown to be mechanoreceptors which respond to changes in joint position, whereas free nerve endings have been identified as nociceptors. Neural innervation were present in the transverse carpal ligament, and the nociceptive information relayed by these neural elements may contribute to the pain associated with carpal tunnel syndrome. In addition to being a mechanical wrist stabilizer, the transverse carpal ligament also may play a role in proprioception of the wrist.

Complications and outcome in open carpal tunnel release. A 6-year follow-up in 92 patients

In this retrospective study, 92 patients (83% attendance rate) were examined 6 years after open carpal tunnel release. A questionnaire was answered by the patient and a physical examination was made by an independent observer. Five complications were found, of which 4 were early postoperative problems and one was a major complication with long-term disability. In one third of the patients numerous complaints were noted even after six years. Recurrences were found in 9 cases. No lacerations of nerves, tendons or vessels were seen and no patient developed reflex sympathetic dystrophy. The overall subjective outcome showed that 91% of the patients were free of symptoms or improved. The grip strength at follow-up was reduced, if the symptoms had been present for more than 12 months, as compared to less than 12 months, (p = 0.009) and when associated, unspecific brachialgia had been present (p = 0.02). No differences were found in conjunction with the operating surgeon being either an orthopaedic resident or a specialist in hand surgery. In conclusion, open carpal tunnel release had a subjectively favourable outcome, but due to complications and postoperative complaints, further investigations into alternative techniques seem necessary.

Pedicled hypothenar fat flap for median nerve coverage in recalcitrant carpal tunnel syndrome

We report the use of a hypothenar pedicled fat flap to cover the median nerve in recalcitrant carpal tunnel syndrome. Forty-five patients with recurrent symptoms after previous carpal tunnel surgery were included in this study. Patients with incomplete release of the transverse carpal ligament were not included. We performed an anatomical study on 30 cadavers. The original technique with the section of the deep branch of ulnar artery was modified. The flap could be transferred onto the median nerve without stretching. The median follow-up was 45 months (range, 12-80 months). Pain completely disappeared in 41 patients with normal nerve conduction. Based on clinical and electromyographic signs, the global results showed excellent results (49%), 19 good results (45%), two average results (4.5%) and two failures (2%). The use of a hypothenar pedicled fat flap to cover the median nerve in recalcitrant carpal tunnel syndrome is a simple and efficient technique which improves the trophic environment of the median nerve and relieves pain.

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 release of the carpal ligament for carpal tunnel syndrome: long-term results using the Chow technique

This report presents the author's experience with the Chow method for endoscopic release of the carpal ligament for carpal tunnel syndrome, with a minimum follow-up of 5 years. The report includes 116 cases (wrists) of 84 patients. The success rate for these cases is 93.3% and the recurrence rate is 0.96%. One temporary ulnar neuropraxia was reported in this group with spontaneous recovery. There were no permanent nerve injuries. Results of 5-year follow-up nerve conduction velocity tests are also included. This report shows that endoscopic release of the carpal ligament for carpal tunnel syndrome, using the Chow method, is a reliable alternative to the open procedure and has produced good, long-term, results.

Innervation density of the base of the palm

Cutaneous nerves of the palm were localized and quantitated by longitudinal axis, proximity to the distal palmar crease, and tissue layer to identify an incision that would avoid injury to the palmar branches of cutaneous nerves. Cadaveric palms (n = 10) harvested en bloc were fixed at physiologic tension and prepared using the celloidin method and hematoxylin-eosin staining. The cutaneous nerves of the palm were counted and classified by their size and location within each tissue layer and longitudinal axis as well as by proximal, middle, and distal locations within each axis. The mean number of large nerves identified within regions of the palm differed by tissue layer and longitudinal axis but not by longitudinal location within axes. The long/ring finger web space was characterized by the lowest innervation density; the index/long finger web space and ring finger axis were characterized by the greatest innervation density. An incision in the long/ring finger web space 2 cm proximal to Kaplan's cardinal line should result in injury to fewer nerves and reduce the incidence of painful neuromas during open carpal tunnel release.

Surgical anatomy of the carpal tunnel

The author describes and details the anatomy of the carpal tunnel and surrounding structures pertinent to the surgical treatment of carpal tunnel syndrome. Potential complications of both open and endoscopic carpal tunnel release are discussed as well as techniques to avoid or minimize poor patient outcomes.

Two-portal endoscopic carpal tunnel release surgery: report of early experience

Endoscopic carpal tunnel release is increasingly performed to treat median nerve entrapment neuropathy at the transverse carpal ligament. Proponents of these procedures claim that there are early postoperative advantages to be gained by the patient in the form of decreased pain and weakness, thus facilitating an earlier return to function. However, serious complications associated with the use of these techniques have been reported, especially during the surgeon's purported initial steep learning curve. A prospective analysis of the authors' first 51 cases using a two-portal endoscopic technique was conducted to determine whether these learning curve complications occurred. The authors did experience a learning curve; however, it was not significant. They encountered no serious complications and patient satisfaction was very high. It is concluded that the procedure is relatively easy to learn and safe to perform.

Results of open carpal tunnel release: a comprehensive, retrospective study of 188 hands

BACKGROUND

Many recent reports of the results of decompression of the median nerve in the carpal tunnel have concentrated on only one aspect of recovery (numbness, grip etc.), and there are no reports of a comprehensive study of outcome. The aim of the present study was to review comprehensively the results of the direct visualization method of decompression of the carpal tunnel and to compare them with the published results of endoscopic release.

METHODS

Patients' perceptions of the severity of pain, numbness and paraesthesiae due to carpal tunnel syndrome (CTS), before and after open carpal tunnel release (CTR) in 188 hands were reviewed retrospectively at a minimum time of follow-up of 18 months. Motor and sensory testing, provocation testing and measurement of scar tenderness in 135 hands were performed at a clinical review.

RESULTS

Subjective results showed that 70% experienced a reduction in the severity of pain after CTR, 78% of hands experienced a reduction in the severity of paraesthesiae and 77% experienced a reduction in the severity of numbness. A total of 49% had improvements in all three symptoms after CTR. At the clinical review, sensory testing revealed that 59% of hands had normal or slightly diminished light touch, 35% had normal static two-point discrimination and 61% had normal dynamic two-point discrimination. Results for Tinel's test, Phalen's test and pressure provocation testing were positive in 10% of hands. There was no scar tenderness in 38%, no persisting thenar atrophy in 90%. Normal grip strength was found in 93% and 91% had normal pinch strength.

CONCLUSIONS

It was concluded that open carpal tunnel release remains a safe and reliable treatment for carpal tunnel syndrome. The very low incidence of serious complications from the open technique of CTR, when compared with endoscopic CTR as published by different authors in the literature, and the comparable clinical results, appears to make the open technique a safer and preferable option. However, a properly controlled trial of both techniques is necessary to compare them.

Ligament lengthening compared with simple division of the transverse carpal ligament in the open treatment of carpal tunnel syndrome

It has been suggested that the new (and controversial) endoscopic techniques are more successful than standard operation for the preservation of the ligamentous pulley function across the carpal tunnel and for the separation of the gliding structures from the subcutaneous tissues after release of the carpal ligament in carpal tunnel syndrome. We therefore decided to study the possible importance of preserving the continuity of the carpal ligament by doing an open lengthening of the ligament. This retrospective, unrandomised study included 99 patients with carpal tunnel syndrome who underwent open release of the carpal tunnel with or without a simultaneous lengthening of the transverse carpal ligament. The duration of follow up ranged from 4-8 years. The group who had the ligament lengthened had significantly longer sick leave (p < 0.01) than the group who had transverse ligament section alone. There were no advantages to reconstruction of the transverse ligament.

Distribution of nerve fibers in the standard incision for carpal tunnel decompression

Twenty-two paired biopsy specimens of skin and subcutaneous tissue from the proximal and distal halves of the conventional curvilinear incision or carpal tunnel decompression were histologically examined. The specimens were immunohistochemically stained with S100 antibody to highlight the nerve fibers. The mean count of free nerve endings in the proximal biopsy site was 4.42/mm2 (SD, 2.97; range, 1.23-12.27), compared to 4.2/mm2 (SD, 2.71; range, 1.01-10.50) in the distal biopsy specimens. This difference was not statistically significant (p = .20, Wilcoxon's signed ranks [matched pairs] test). The proximal incision site for carpal tunnel decompression did not appear to be more neuroreceptive than the distal incision site, providing no support for the implication of proximal incision sites in proximal scar tenderness.

Anatomy of the palmar cutaneous branch of the median nerve: clinical significance

A detailed anatomic, histologic, and immunohistochemical study of the palmar cutaneous branch of the median nerve (PCBMN) and its distal arborization was undertaken on 12 fresh human cadaveric hands. Small unmyelinated fibers terminated in the superficial loose connective tissue of the transverse carpal ligament. There were no nerve fibers detected in the deep, dense collagen aspect of the ligament. Based on these findings, during open carpal tunnel release, the skin incision should be placed along the axis of the ring finger to avoid injury to the superficial branches of the PCBMN. When open release is used, the very small terminal branches in the loose tissue of the ligament will be transected; this may in part be responsible for postoperative soft tissue pain. For endoscopic releases, some risk for transection of the main trunk of the PCBMN at the proximal incision exists. Repeated passes of the endoscopic knife should be avoided in an attempt to limit damage to the small fibers in the superficial aspect of the ligament.

Biomechanical alterations in the carpal arch and hand muscles after carpal tunnel release: a further approach toward understanding the function of the flexor retinaculum and the cause of postoperative grip weakness

The difference between maximal and minimal distance covered (the distance between the trapezium ridge and hamate hook; moment exerted on structures: 1 Nm) by an intact flexor retinaculum (FR; minimum, 3.3 +/- 0.1 cm; maximum, 3.7 +/- 0.2 cm) and the increase in the maximal distance on carpal tunnel release (CTR; increase, 1.6 +/- 0.2 mm) were significant. Under an external supination moment, the distance between the attachments of the trapeziopisiform band increased after CTR. Under external pronation and ulnar abduction moments, the distance between the attachments of the scaphoideohamate band increased after CTR. The CTR resulted in an anatomic attachment loss for the following muscles: the superficial head of the flexor pollicis brevis (shortening by approximately 25%, relative to rest length), the ulnar part of the abductor pollicis brevis (with opposition and adductory functions, approximately 20%), the opponens pollicis (approximately 20%), the middle part of the abductor pollicis brevis (approximately 7%), and the opponens digiti minimi (approximately 10%). Preoperative and postoperative (2-7 weeks after surgery) measurements of the reaction force of the distal phalanx (under isometric thumb opposition and finger II-IV flexion with extended carpal joint) led to differentiation of three groups: (1) significant strength loss--the patients showed difficulties with grasping, lifting, twisting off lids and caps, screwing, pulling ropes, and pinching; (2) no significant change in force values; and (3) a significant increase in strength (patients who could grip more firmly).

Sequelae of carpal tunnel surgery: rationale for the design of a surgical approach

The sequelae of carpal tunnel surgery were reviewed and were presumed to be associated with the linear vertical section of the transverse carpal ligament because this was the common element in the reported series. The authors adopted a modified approach, substituting a parabolic incision that left a protective flap of the ligament to cover the structures within the tunnel in the area of maximum convexity of the wrist. The results from a recent series of 100 cases were contrasted with a control series of 770 previous cases. Untoward postoperative sequelae were significantly reduced through this modified approach. The improved results, the authors conclude, were attributable to a reduction of pressure within the carpal tunnel, while avoiding the wide gaping of the tunnel space that is associated with vertical incisions, which may allow an anterior displacement of the median nerve and flexor tendons between the cut ends of the transverse carpal ligament and sometimes result in a continuous scar through the skin.

Endoscopic carpal tunnel release: a prospective study of complications and surgical experience

A 63-center prospective study of endoscopic carpal tunnel release using the Agee Carpal Tunnel Release System was conducted in 1049 procedures in 988 patients. Prior experience with endoscopic release varied significantly among surgeon participants. Surgeons evaluated the newly redesigned system for blade visibility, blade height, and mechanical function. Data on patient complications were collected at the time of surgery and 3-4 weeks postoperative. The results indicated minimal complications and no confirmed injuries to vessels or nerves; the symptoms from one possible digital nerve injury eventually resolved completely. Surgeons were able to observe the point of entry of the blade into the transverse carpal ligament in 97.5% of procedures. Introduction of the blade assembly into the carpal tunnel was rated easy or adequate in 90.6% of procedures, and blade height was rated adequate in 97.4% of procedures.

Biomechanical changes after carpal tunnel release: a cadaveric model for comparing open, endoscopic, and step-cut lengthening techniques

We used a previously described cadaveric model for evaluating changes in flexor tendon biomechanics after open carpal tunnel release to evaluate endoscopic and step-cut lengthening techniques. A 26% and 18% increase in tendon excursion consumed by wrist motion was demonstrated for flexor digitorum profundus and flexor digitorum superficialis tendons respectively after open transection of the transverse carpal ligament. A 21% and 15% increase in tendon excursion was demonstrated after endoscopic carpal tunnel release and a 21% and 16% increase after step-cut lengthening of the transverse carpal ligament. Increased excursion was noted after 20-30 degrees of wrist flexion as tendon bowstringing occurred. Although division of the transverse carpal ligament by all methods resulted in a significant increase in tendon excursion, the differences between methods of carpal tunnel release were not significant. This cadaveric study evaluates one potential cause for weakness after carpal tunnel release, palmar displacement of the flexor tendons, which results in increased flexor tendon excursion consumed by wrist motion.

Anatomical variations of the median nerve in the carpal tunnel

The median nerve was explored in 100 hands and the variations classified by the Lanz system. Only 47.7% of hands showed the standard anatomy described in textbooks. Rare variations were also found. Knowledge of the variable anatomy of the nerve could help to avoid incomplete decompression at operations for carpal tunnel entrapment and injury to the thenar branch of the nerve. The possibility of double thenar innervation must be considered in preoperative evaluation and in the follow up of median nerve injuries.

Median nerve injury and the transverse wrist crease incision in open carpal tunnel release

The author has recently had referred to him three patients with median nerve injuries who have had open carpal tunnel decompression via a small transverse wrist incision. Despite previous adverse reports, some surgeons persist with this technique.

The palmar cutaneous branch of the median nerve and the palmaris longus tendon: a cadaveric study

The purpose of this study was to determine the frequency with which the palmar cutaneous branch of the median nerve passes through the palmaris longus tendon. Fifty-two wrists (27 cadavers) were dissected. In three wrists the palmaris longus tendon was absent. The palmar cutaneous branch was seen to course through the fibers of the palmaris longus in two specimens (different cadavers). The nerve passed through the tendon 1 and 1.5 cm proximal to its insertion into the palmar aponeurosis. In the presence of this anomaly the palmar cutaneous branch of the median nerve is at risk of injury during harvesting of the palmaris longus tendon for grafts. To avoid injury, we recommend transecting the tendon 2 cm proximal to its insertion into the palmar aponeurosis.

Endoscopic carpal-tunnel release in cadavera. An investigation of the results of twelve surgeons with this training model

Endoscopic carpal-tunnel releases were performed, with use of the two-portal technique described by Chow, on twenty-four fresh or fresh-frozen wrist specimens from cadavera. Twelve surgeons were taught the technique in the cadaver model by an experienced colleague. Nine surgeons performed one endoscopic carpal-tunnel release; three performed three or more. Incomplete release of the transverse carpal ligament was noted in nine specimens (38 per cent). The percentage of incomplete releases was the same for both the surgeons who performed one endoscopic carpal-tunnel release and those who performed three or more. Complications occurred in four specimens (17 per cent) and included lacerations of an ulnar artery and a median nerve, partial laceration of a flexor tendon, and a fracture of the hook of the hamate. The observed complications and incomplete releases of the transverse carpal ligament in this training model emphasize the risks that may occur when a surgeon is first learning this procedure.

Endoscopic carpal tunnel release: the guide tube technique

This article introduces a modification of the Chow double-portal endoscopic carpal tunnel release and reviews the results of 71 endoscopic carpal tunnel decompressions performed on 50 consecutive patients over a 20-month period. The guide tube technique was developed to improve patient safety and provide good ligament visualization. In the clinical study, 33 patients not receiving workers' compensation were ready to return to work at 12 days (mean). The 17 patients receiving workers' compensation were divided into two groups: workers with carpal tunnel syndrome only and workers with carpal tunnel syndrome and associated musculoskeletal pain syndromes. The 11 workers with carpal tunnel syndrome alone returned to work by 74 days (mean). The six workers with carpal tunnel syndrome and myofascial pain took 160 days (mean) to return to work. The complication rate was 1.4%. Based on this small retrospective study, the guide tube technique achieved safe and easily reproducible surgical results.

Median nerve compression in the proximal forearm

Thirty-nine limbs in 36 patients underwent surgical decompression of the median nerve in the proximal forearm. Seventeen patients with 19 limbs had prior ipsilateral carpal tunnel releases, and 24 had workers' compensation claims related to heavy labor or repetitive tasks. The most common presenting complaints were paresthesias/numbness in the distribution of the median nerve and pain in the forearm or hand. The most common physical finding was a positive pronator compression test, followed by median nerve hypesthesia. Elbow to wrist nerve conduction tests were obtained in 37 of 39 limbs and were abnormal in 12. Intraoperatively, the nerve was compressed at the flexor digitorum superficialis tendon in 22 limbs, pronator teres in 13 limbs, and both in 4 limbs. Postoperatively, 30 limbs had complete or partial relief of symptoms; in a sub-group of 19 limbs that had a prior failed carpal tunnel release, 14 had complete or partial relief. Although there was a trend toward better results in patients with normal preoperative nerve conduction tests and intraoperative compression at the flexor digitorum superficialis, the difference was not significant.

Endoscopic carpal tunnel release: an anatomic study

Endoscopic carpal tunnel release has been shown to decrease postoperative recovery time in patients undergoing surgery for carpal tunnel syndrome. There is, however, some controversy concerning the safety and reliability of the procedure. We performed endoscopic carpal tunnel release utilizing the two portal technique described by Chow on 20 fresh cadaver specimens. There were no injuries noted in any of the vital structures including the ulnar artery, superficial palmar arch, third common digital nerve or flexor tendons. The transverse carpal ligament was found to be completely transected in 95% of the specimens. Hyperextension of the wrist significantly displaces the vital structures both dorsally and distally. The use of a slotted cannula and specially designed blades protect the surrounding structures during the procedure. Based on this study, endoscopic carpal tunnel release using the technique described by Chow may be performed reliably without injury to any of the vital structures.

Transverse carpal ligament reconstruction in surgery for carpal tunnel syndrome: a new technique

We present a two-year follow-up of a technique to reconstruct the transverse carpal ligament in surgery for carpal tunnel syndrome. The transverse carpal ligament is exposed through a four to five centimeter palmar incision in line with the axis of the ring finger. The ligament is divided in step-wise fashion, creating a distal radially-based flap and a proximal ulnarly-based flap. The apices of these flaps are approximated, lengthening the ligament six to ten millimeters. All seventy-three patients (one hundred-four hands) reported substantial improvement with 93% having complete resolution of symptoms. Ninety-seven percent returned to work (average disability, two months). There were no recurrences or significant operative complications. In those with unilateral reconstruction (60%), there was no diminution in grip strength (p less than 0.05). This technique of transverse carpal ligament reconstruction stabilizes the transverse carpal arch, provides protection to the median nerve, prevents bowstringing of the flexor tendons, and maximizes postoperative grip strength.

Palmar cutaneous branch of the median nerve

The palmar cutaneous branch of the median nerve was dissected in 25 fresh cadavers. The origin from the median nerve, the course, termination, and variability of the palmar cutaneous nerve are described in relation to two reference lines. In no case did a branch of the palmar cutaneous nerve extend ulnar to the axial line of the ring finger. The planning of incisions around the palmar aspect of the palm and wrist should be based on this anatomical knowledge.