Human carpal ligament recruitment and three-dimensional carpal motion

In five fresh human cadaver wrist joints six carpal ligaments and seven carpal bones were marked with small, radio-opaque pellets. Using a roentgenstereophotogrammetric measuring system, the ligamentous length changes and the kinematics of carpal bones were determined in different flexion and deviation positions of the hand. The data generated by this method differ significantly from lengthening data predicted by current concepts on carpal ligament functioning. The motions of carpal bones and the lengthening of the carpal ligaments were related to each other. It appeared that most carpal ligaments lengthen only during one half of a full movement cycle. Hence, ligaments seem to constrain either a dorsal- or a palmar-directed motion of the hand, or an ulnar- or a radial-directed motion of the hand. When the hand is in maximal radial deviation or maximal palmar flexion, none of the ligaments has a greater length than in the neutral situation. The tested parts of the lunatotriquetrum palmar ligament do not lengthen during any movement of the hand. Significant lengthening relative to the neutral situation was found for the radiocapitate palmar ligament (6.5% in maximal ulnar deviation and 11.7% in maximal dorsal flexion of the hand), and for the distal string of the radiolunate palmar ligament (6.4% in maximal ulnar deviation). It was confirmed that the carpals, apart from moving in the plane in which the hand motion takes place, also execute considerable out-of-plane motions during hand motions. The combination of these experimentally and simultaneously determined data on length change and on the movements of carpal bones are found to be necessary in order to give suitable explanations for the observed separate kinematical phenomena.     

Relationship of carpal canal contents volume to carpal canal pressure in carpal tunnel syndrome patients

Forty patients long-term haemodialysis with a second recurrence of carpal tunnel syndrome and concomitant loss of flexor tendon function due to flexor adhesions were treated by excision of the flexor digitorum superficialis tendons. During the procedure the carpal canal pressure was measured using a continuous infusion technique. The preoperative mean carpal canal pressure was 81 (SD, 53)mmHg. After removal of all the flexor digitorum superficialis tendons, the carpal canal pressure decreased to 10 (SD, 8)mmHg. The clinical symptoms of carpal tunnel syndrome were relieved and hand strength and finger motion were improved in all patients.     

Segmental carpal canal pressure in patients with carpal tunnel syndrome

PURPOSE: To clarify which part of the median nerve is the most compressed and to compare carpal canal pressure with the latency of the sensory nerve potential and the duration of symptoms. METHODS: Fifteen patients with idiopathic carpal tunnel syndrome were studied using a pressure guidewire system to record canal pressure. The wire was introduced from the distal end of the carpal canal to 2 cm proximal to the distal wrist crease (DWC) and then retracted in 5-mm increments using an image intensifier to guide the progress. A nerve conduction study was performed, and all patients were asked how long the symptoms lasted. RESULTS: Carpal canal pressure was significantly higher 5 to 15 mm distal to the DWC. The most compressed point was 10 mm distal to the DWC, with a pressure of 44.9 +/- 26.4 mm Hg. The correlation coefficient between the highest canal pressure and the latency was 0.393 and between highest canal pressure and duration of symptoms was 0.402. CONCLUSIONS: Our study showed that the most compressed part of the median nerve in the carpal canal is 10 mm distal to the DWC. The carpal canal pressure was related to the latency and to the duration of symptoms.     

Symptomatic carpal coalition

The carpus is initially a cartilaginous structure that subsequently demarcates into separate carpal bones. Failure of differentiation of parts results in carpal coalition, the most common of which occurs between the lunate and triquetrum. Lunate-triquetral coalitions can be subdivided into four types according to the degree of union. Four types are identified. A case report of type I is presented that responded to a lunate-triquetral fusion.     

Ulnar carpal instabilities

Ulnar carpal instabilities are more common than previously suspected. To date, instability patterns have been described at the triquetrolunate and triquetrohamate joints. In this article, the pathomechanics, diagnosis, and treatment of these instability patterns are reviewed and several pertinent case reports are presented.     

Traumatic carpal instability

In general, two patterns of traumatic carpal instability can be discerned: palmar flexion intercalated segmental instability (PISI deformity) and dorsiflexion intercalated segmental instability (DISI deformity). Two case reports are described, demonstrating both types and their treatment. PISI deformity, seen less frequently, may require Kirschner wiring as well as plaster immobilization. DISI deformity with malunion may require osteotomy. The underlying causes should be sought before treatment is initiated.     

Uncommon carpal fractures

Fractures of the hand are frequently encountered with injuries to the phalanges and metacarpals comprising the vast majority. Fractures of the carpal bones excluding the scaphoid, however, are fairly uncommon. Despite the rarity of fractures of the remaining seven carpal bones, they can cause a disproportionate amount of morbidity from missed diagnosis due to their subtlety as well as their frequent association with significant ligamentous disruption or even other carpal bone fractures. Delayed diagnosis can result in inadequate fracture care, which places the wrist at risk of disabling sequelae. This review focuses on the current concepts of pathophysiology, diagnosis, and treatment of carpal fractures other than the scaphoid.     

Treatment of carpal tunnel syndrome by low-level laser versus open carpal tunnel release

Carpal tunnel syndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist. It is one of the most common peripheral nerve disorders. The cause of idiopathic CTS remains unclear. The diagnosis of CTS is still mainly clinical. Open carpal tunnel release is the standard treatment. The present study was conducted to evaluate the effectiveness of low level laser treatment (LLLT) for CTS in comparison to the standard open carpal tunnel release surgery. Out of 54 patients, 60 symptomatic hands complaining of CTS were divided into two equal groups. Group A, was subjected to LLLT by Helium Neon (He–Ne) laser (632.8 nm), whereas group B was treated by the open approach for carpal tunnel release. The patients were evaluated clinically and by nerve conduction studies (NCSs) about 6 months after the treatment. LLLT showed overall significant results but at a lower level in relation to surgery. LLLT showed significant outcomes in all parameters of subjective complaints (p ≤ 0.01) except for muscle weakness. Moreover, LLLT showed significant results in all parameters of objective findings (p ≤ 0.01) except for thenar atrophy. However, NCSs expressed the same statistical significance (p ≤ 0.01) after the treatment by both modalities. LLLT has proven to be an effective and noninvasive treatment modality for CTS especially for early and mild-to-moderate cases when pain is the main presenting symptom. However, surgery could be preserved for advanced and chronic cases. Refinement of laser tools and introduction of other wavelengths could make LLLT for CTS treatment a field for further investigations.     

腕管切开松解减压术

腕管切开松解减压术一直被认为是外科治疗腕管综合征的经典方法，于1913年由Marie和Foix最先提出。其术式甚多，优、缺点各异，操作也有简有繁。现结合腕部神经解剖特点，将每一种术式归纳复述如下。     

Dynamic mesh of carpal scaphoid

Despite the use of cannulated compression screws, it is still difficult to screw non-displaced fractures of the scaphoid percutaneously. That is due in particular to the difficulty in assessing the correct position for the guide pin from the 2D fluoroscopic images. This work is designed to enable 3D visualisation of the scaphoid during surgical operations by using the technique of dynamic meshing and having the image appearing on a computer screen rather than as a mental image. In this context, the MEFP3C software includes applications for converting a generic scaphoid into a virtual scaphoid, based on the fluoroscopic 2D images of a given scaphoid. These applications include a module for acquiring a cloud of points, a modeller, a dynamic meshing system, an animation module, a texture module and a multi-resolution meshing system. The result of this process, the virtual scaphoid, in spite of the imperfections, enables images to be obtained comparable with those from tomodensitometric reconstruction of the same scaphoid specimen. The virtual scaphoid can be moved over the computer screen in the three spatial planes in translation, rotation and scaling. In conclusion, we think that dynamic meshing is a powerful, simple and ergonomic method of viewing a scaphoid in 3D, which could, in future, be routinely integrated into the fluroroscopic monitor.     

Non-union of the carpal navicular

An analysis of methods of treatment with special regard to compression screw osteosynthesis. During the years 1965 to 1980 a total of 96 patients was treated with different types of procedure for non-union of the carpal navicular. The location and type of the fractures confirms previous reports that the chances of healing of proximal and oblique fractures of the navicular are poor. Most of the patients were operated on with compression screw osteosynthesis. In our experience which was confirmed by a follow-up examination at two to fifteen years following treatment, compression screw ostheosynthesis seems to be the better method of handling navicular non-unions.     

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. Received for publication on June 23, 1998; accepted on Oct. 30, 1998     

Congenital carpal tunnel syndrome

A case of congenital carpal tunnel syndrome associated with melorheostosis is described. The symptoms were lack of use of the hand since birth, hypotrophy of the fingers innervated by the median nerve, and severe atrophy of the thenar muscles. The total degeneration of the nerve in the carpal tunnel was successfully treated with a sural nerve graft.