Journal of Hand Surgery (European Volume)

A study of endoscopic carpal tunnel release was carried out in three parts, consisting of initial cadaveric dissections, a prospective pilot study of 20 patients and a prospective, randomized trial of 71 patients comparing endoscopic with open decompression. In the main trial, 25 patients with bilateral symptoms underwent simultaneous endoscopic and open release, with the remainder randomized to one or other technique. Both techniques effectively decompressed the median nerve. A significant improvement in grip and pinch strength over 3 months was achieved in those undergoing endoscopic surgery. Average return to work was 14 days in the endoscopic series and 39 days in the open series. A complication rate of 35% was achieved with the transbursal endoscopic technique, 3.7% with the extrabursal endoscopic technique and 13.5% in the open series.

We retrospectively compared two similar groups of patients who underwent either endoscopic decompression of the carpal tunnel (single portal technique, 44 patients) or open decompression (58 patients) during 1 year in our department. To find out whether there was any subjective difference between the results of the two techniques, we sent each patient a questionnaire and received a 95% response. No major complications occurred. Three endoscopic decompressions had to be abandoned, and open release was performed. We could not demonstrate any significant difference in relief of symptoms and return to work between the two groups. Patient satisfaction at 6 to 18 months follow-up was high with both techniques.

83 hands in 69 patients had endoscopic carpal tunnel release by the Chow method over a 14-month period. 78% of these had a satisfactory outcome with relief of symptoms and no complications. Poor results were explained by incomplete ligament division (five patients), wrong diagnosis (two hands), and post-operative nerve problems (five hands). Two patients after Colles’ fractures had unsatisfactory results. Serious complications included two median nerve lacerations. One of these was clearly a result of deviation from the standard protocol. The authors believe that the technique has advantages over open release but they are divided on whether the benefits outweigh the risk of nerve injury.

A case is reported in which the median nerves bifurcated bilaterally, with the radial segment of each nerve passing through an accessory ligamentons compartment within the carpal tunnel.

The boundaries of Guyon’s canal have recently been redefined by a series of anatomical dissections. These showed that the confines of this space do not extend from the pisiform to the hook of the hamate, as currently accepted. The fascial roof extends radial to the hook of the hamate, which allows the ulnar neurovascular bundle to course radial to the hamate hook. The position of the ulnar nerve and artery is of particular significance for endoscopic carpal tunnel release. Most endoscopic devices are designed to divide the flexor retinaculum just to the radial aspect of the hamate hook. Utilizing cross-sectional analysis of nine cadaver specimens, we found the ulnar artery to course radial to the hamate hook in five and palmar to it in four. Therefore, the ulnar artery may be at greater risk of injury during endoscopic procedures than previously recognized.

Intermittent occlusion of the ulnar artery developed in a patient causing cramp in her right hand. Both flexion and extension of the wrist completely obstructed bloodflow in the ulnar artery, a level just proximal to the wrist. At operation, a tight hand of antebrachial fascia was found to the cause of this intermittent arterial occlusion. Surgical release of this fascial ban reduced complete relief of her symptoms.

As part of a continuing study of the causes of carpal tunnel syndrome (CTS) in industry, we measured sensory conduction of the median nerve in 101 Japanese furniture factory workers. We used the maximum latency difference (MLD) with a critical value of ≥0.40 msec to indicate abnormal slowing of nerve conduction. The prevalence of slowing in the Japanese workers was 17.8%, while the prevalence of probable CTS (based on symptoms only) was 2.5%, and the prevalence of definite CTS (probable CTS confirmed by slowing) was 2.0%. The most important factor predicting the MLD was the body mass index. The MLD was the most important factor predicting probable CTS. The prevalence of slowing in the Japanese workers was not significantly different from the prevalence of slowing in 316 American workers from four industries (22.0%), but the prevalences of probable CTS and definite CTS were much lower in the Japanese. The meaning of these findings is discussed.

In 15 carpal tunnel syndrome patients pressure was measured during the day and at 2-hourly intervals from midnight to 6 a.m., via a catheter introduced into the carpal canal, using the constant infusion technique. Intracarpal tunnel pressure of the patients always exceeded the critical pressure of 30 mmHg and the highest values were found at 6 a.m. Slightly lower pressures were found when the wrist was splinted, but the difference was not significant, nor were critical pressure levels prevented by splinting.

Some cases of cubital tunnel syndrome are caused by anatomical abnormalities such as the epitrochleo-anconeus muscle or snapping and bulkiness of the medial head of the triceps brachii muscle. We report a rare cause of cubital tunnel syndrome that has not been reported previously. It was caused by an abnormal insertion of the medial head of the triceps muscle into the medial epicondyle. The clinical course and operative findings are described.

Pronator teres syndrome is a compressive neuropathy of the median nerve in the proximal part of the forearm and distal part of the arm. The outcome of surgical decompression is occasionally unsatisfactory because of a poor scar. We present the use of a transverse skin incision that allows adequate exploration and decompression distally and proximally, beneath the subcutaneous tissue beyond the volar elbow crease.

Fibrin sealing, with or without sutures, has become a commonly used technique in human nerve grafting with clinically good results, but is seldom used in primary repair of peripheral nerves. A prospective study was designed to evaluate the incidence of dehiscence in the traditional (Tisseel Kit) and a new “ready-to-use” fibrin seal preparation (Tisseel Duo), and the outcome following fibrin sealing was compared with microsurgical repair of peripheral nerves in rats. No dehiscence was seen in the Tisseel Duo group compared with 20% in the Tisseel Kit group. The electron micrographic evaluation following regeneration showed no significant difference from the microsuture group. Tisseel Duo should therefore be used instead of the traditional fibrin seal preparation when no sutures are used, and may prove to be an alternative to microsuture of peripheral nerves.

Traditional histological staining techniques, as well as elastin-specific antibodies and electron microscopy, have been used to assess the distribution of elastin within the peripheral nerve. The location of the elastin identified by the VerHoeff-VanGiesen or Weigert stains has been shown to coincide with the unambiguous identilication of elastin by immunospecific stains and electron microscopy. Elastin is located in all three connective layers of the peripheral nerve. Thick elastic fibres, consisting of amorphous elastiu protein and microfibrils, are located consistently in the perineurium and, to a lesser extent, in the epineurium. The endoneurium contains small collections of elastic fibres widely distributed between the axons. Compared with collagen, the overall content of elastin, however, is small, suggesting that the visco-elastic properties of peripheral nerve may be due primarily to collagen.

Findings in 34 patients with traumatic brachial plexus injury documented by surgical exploration and intra-operative somatosensory-evoked potentials were correlated with findings on myelography and magnetic resonance imaging (MRI) to determine whether MRI can identify nerve root avulsion. The coronal and sagittal planes were not able to demonstrate avulsion of the individual nerve roots. The axial and axial oblique planes did provide useful information to determine which nerve root was avulsed in the upper plexus, although it was difficult to clearly delineate the lower cervical rootlets. The accuracy of MRI was 73% for C5 and 64% for C6 and that of myelograpby 63% for C5 and 64% for C6. Thus, the diagnostic accuracy of MRI for upper nerve roots was slightly superior to myelography. Although its primary diagnostic value is limited to the upper nerve roots whose avulsion is relatively difficult to diagnose by myelography, MRI can provide useful guidance in the waiting period prior to surgical exploration after brachial plexus injury.

Experimental rat models of simulated brachial plexus injuries were devised to compare the effect of contralateral C7 root transfer with phrenic neurotization. The effect of vascularized nerve grafting (VNG) was also compared with the use of conventional nerve grafts (CNG) in the treatment of root avulsion of the brachial plexus. 160 rats were randomly divided into four groups of 40 each; contralateral C7 root transfer with a vascularized ulnar nerve graft (C7-VNG), contralateral C7 root transfer with conventional ulnar nerve grafting (C7-CNG), ipsilateral phrenic nerve transfer with a vascularized ulnar nerve graft (P-VNG) and ipsilateral phrenic nerve transfer with conventional ulnar nerve grafting (P-CNG). Electrophysiological and histological examinations and functional evaluation were performed at different post-operative intervals. C7 root transfer was found to be superior to phrenic nerve transfer and VNG superior to CNG. Severance of the C7 nerve root was not found to affect limb function on the healthy side.

50 patients with root avulsion of the brachial plexus have been treated with contralateral C7 root neurotization. Abnormal cutaneous sensation was found on the index finger in 37 cases (74%), on the middle finger in 29 cases (58%), on the thumb in 19 cases (38%), on the ring finger in ten cases (20%), and on the little finger in one case (2%). Seven patients had no abnormal cutaneous sensation. It is suggested that the area of skin innervated by C7 is centred on the index finger together with the thumb and middle fingers.

Since 1986, contralateral C7 root transfer has been used to treat brachial plexus root avulsions in our hospital. We performed post-operative electrophysiological examinations of the healthy-side limb in the first 27 patients. Electromyography and nerve conduction studies on the healthy side demonstrated mild abnormalities only of individual limb muscles in a few cases. These changes mostly recovered during the follow-up period. In the measurement of radial nerve motor conduction, median nerve sensory conduction and somato-sensory evoked potentials, we found that the amplitude of the median nerve sensory conduction alone was slightly lower than that of the control group (p < 0.05). The results showed that severance of C7 caused no permanent functional damage to the upper limb.

A randomized prospective clinical study was carried out in 33 patients (37 lingers) with lacerations of both FDS and FDP tendons in the area covered by the A2 pulley, that is, zone 2C in Tang’s subdivision of no man’s land. Both lacerated tendons were repaired in 19 fingers and repair of only FDP with regional excision of FDS were performed in 18 fingers. Follow-up of average 12 months revealed that there was no significant difference in the end results evaluated according to the TAM system. The average TAM was 204° in the fingers with suture of FDP only and 187° in those with suture of both tendons. The fingers with suture of both tendons showed a higher rate of re-operation due to adhesions or rupture of repair. This study suggests that it is better to repair only FDP with regional excision of FDS when both tendons are injured in zone 2C.

We have reviewed 22 flexor tendon repairs in zone 1 undertaken in Hobart, Tasmania, during the period 1986 to 1991. The repairs were assessed using both ultrasound and Strickland’s clinical criteria. The results are presented, and the two methods of assessment compared. A new method of grading results is proposed based on the ultrasound findings.

We have demonstrated that ultrasound has an important role to play in assessing tendon repairs, both in the on-going management and as an objective method of measuring the results of repair.

Snapping at the MP joint of the little finger can occur when the extended and ulnarly abducted MP joint is flexed. In musicians, this is characterized by an annoying loss of fluid motion, and discomfort. Clinical examination reveals radial subluxation of the connexus intertendineus across the head of the fifth metacarpal to be the underlying problem, and surgical exploration confirms this. Operative treatment for radial subluxation of the connexus intertendineus must preserve the delicate balance of the extensor assembly of the fingers, including the otherwise underestimated connexus intertendineus itself. A simple and effective surgical procedure is presented.

Disruption of the central slip is the primary defect leading to boutonnière deformity. In the closed injury early diagnosis of this lesion is rarely achieved due to the limitations of current methods and difficulties encountered in assessing a painful finger. We describe a simple, non-invasive method of diagnosis which can be carried out on all patients and with minimal discomfort. This test is also beneficial in monitoring the progress of conservative management of central slip disruption.

A series of 29 patients is presented in which 40 dorsal full-thickness defects of the reconstructed using homodigital flaps advanced distally with V-Y closure of the donor defect.

The authors have developed a new skeletal traction system for comminuted intraarticular fractures and fracture-dislocations in the hand. The system consists of two or three Kirschner wires and rubber bands, and is easy to assemble. It is more compact and comfortable than the banjo splint, and equally effective, and it allows early motion of the affected digits.

A description of the technique is followed by the clinical results of seven cases of severe articular injuries in the hand. At the time of follow-up, the average range of the affected PIP joint motion was about 80° The final active motion of the injured DIP joint ranged from 0 to 40° in flexion and that of the affected thumb (trapezia1 fracture) was not limited. The average follow-up period was 13.1 months.

12 adult cadaver wrists were dissected to identify the regions of origin of the four palmar radio-carpal ligaments. A non-dimensionalized value, called the radio-carpal ligament ratio (RLR), was defined as the width of ligament origin from the radius divided by the length of the capitate. Both values were measured directly from radiographs of the cadaver specimens. The RLRs for the four palmar radio-carpal ligaments were found to be statistically consistent.

We applied the RLR concept retrospectively to 20 wrists with intraarticular distal radius fractures requiring open reduction. It was found that those fracture patterns in which the fracture fragment ratios (FFR: widths of the fracture fragments divided by the length of the capitate) were outside the limits of corresponding RLRs had clear intra-operative evidence of palmar radio-carpal ligament disruption, while those with FFRs within the limits of corresponding RLRs were noted to have no ligament disruption.

In a retrospective study, patients with suspected scaphoid fracture had an average of three sets of scaphoid radiographs prior to scintigraphy. Scans were performed an average of 3 months after injury and many were inconclusive because of disuse changes.

A prospective analysis of early scintigraphy in 35 cases over 18 months was carried out. Scans were performed at an average of 15.5 days after injury in selected cases. Patients had an average of 1.28 sets of negative radiographs prior to scanning. There were no false negative scans and in 13 with focal uptake a wrist fracture was demonstrated. Diffuse uptake was thought to be indicative of ligamentous damage or reflex sympathetic dystrophy. Early scintigraphy was found to be a sensitive, reliable and cost-effective examination in cases of suspected significant wrist injury.

Previous studies have shown that young men have the highest frequency of occupational hand injuries. This study investigated their incidence and severity in relation to age and sex.

For occupational hand injuries in general the estimated incidence rate was 17.1 per 1,000 person years. The incidence was found to be higher among men than women in all age groups below 60 years. The incidence for minor injuries declines with increasing age, but the rates for significant injuries are independent of age.

The higher incidence rate for minor injuries among young patients could be real, but it could also be partly due to selection bias, if older patients with minor injuries consult the hospital for treatment less frequently.

12 hands with congenital short finger in 11 patients were treated with various types of metacarpal bone lengthening. These included three patients with brachydactyly, seven with transverse deficiency, and one with constriction ring syndrome. All cases involved metacarpal lengthening and surgery was performed 16 times in 15 digits. Single-stage lengthening was performed in seven cases, on-top plasty in three cases, and distraction lengthening in six cases. The length gained ranged from 2 to 10 mm in single-stage lengthening, 3 to 17 mm in on-top plasty, and 12 to 30 mm in distraction lengthening. Delayed union and malunion occurred in single-stage lengthening or on-top plasty. After metacarpal lengthening, pinch function was improved in seven out of eight patients with either transverse deficiency or constriction band syndrome, and aesthetic improvement was achieved in three patients with brachydactyly.