Morphometric analysis of collagen fibrils in idiopathic carpal tunnel syndrome

Surgical biopsies of dissected transverse carpal ligaments of patients with idiopathic carpal tunnel syndrome were examined with an electron microscope revealing collagen fibrils with varying diameters. Morphometric analysis of transversely cut collagen fibrils was performed on photomicrographs exhibiting fibrils with a small diameter comparable to that in normal tissue as well as fibrils with a large diameter that could not be observed in normal tissue.     

A new testing device for measuring gliding resistance and work of flexion in a digit

In order to move the finger the tendon force must overcome the gliding resistance of the tendon as well as the forces to move the joints, finger inertias, and external load. These sources, combined, make up the work of flexion (WOF) which has been experimentally used to evaluate the finger function. In this study, we have designed a new device, which can measure the forces at the proximal and distal end of the tendon during finger flexion, so that gliding resistance can be isolated from the WOF. Two index fingers from a pair of human cadaver hands were used for testing this device. Preliminary data showed that internal resistance occupied about 10% of WOF with an intact tendon. However, after tendon repair, the gliding resistance increased 31% of WOF for a modified Kessler repair and 50% of WOF for a Becker repair compared to intact tendon. We simulated joint stiffness by injection of saline solution into the proximal interphalangeal joint. This increased the overall WOF but not the gliding resistance. We believe that this testing device provides a useful tool to evaluate finger function after tendon repair in an experimental model.     

Morphometric analysis of collagen fibrils in idiopathic carpal tunnel syndrome: Part 2

Morphometric parameters were evaluated in order to analyze the relation between number and covered area of collagen fibrils in normal and carpal tunnel syndrome tissue. This analysis revealed that in normal tissue twice as many collagen fibrils as in pathological tissue occupy an equal area. Taking these facts into account, some hypotheses are advanced.     

Estrogen and progesterone receptors in carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a compression median nerve neuropathy common in women at menopausal age. The aim of this work was to study immunohistochemically the expression of estrogen (ER) and progesterone (PR) receptors in CTS and control specimens. Biopsies of transverse carpal ligament (TCL) and flexor tendon synovitis were collected from 23 women and from 7 men undergoing surgery for median nerve decompression at the wrist for CTS. In TCL and synovial tissue, cells expressed ER and PR with statistically significant differences related to the age and sex of patients. Immunoreactivity was observed in fibroblasts of TCL, and in lining cells and fibroblasts of synovial tissue. In women, the number of ER-positive cells in the TCL and synovial tissue increased with the age, peaking at 55-70 years, and then decreasing. PR-immunoreactivity was observed only in fibroblasts of TCL and its expression decreased with age, while no immunolabeling was found in the synovial tissue. In TCL samples, the number of ER- and PR-positive cells in non-CTS patients was significantly lower than in CTS patients. These results demonstrate that ER and PR are present in TCL and flexor tendon synovitis, suggesting a role for sex steroid hormones in the pathogenesis of CTS disease.     

Involvement of tenascin-C and PG-M/versican in flexor tenosynovial pathology of idiopathic carpal tunnel syndrome

Increased intra-carpal-tunnel pressure due to swelling of the flexor tenosynovium is the most probable pathological mechanism of idiopathic carpal tunnel syndrome (CTS). To clarify the role of tenascin-C and PG-M/versican, which have often been found to be involved in tissue remodeling and vascular stenosis in the pathogenesis of CTS, we histologically and biochemically examined the production of extracellular matrix in the flexor tenosynovium from 40 idiopathic CTS patients. Tenascin-C was temporarily expressed in the vessel wall, synovial lining and fibrous tissue, with expression regulated differently in each tissue. Tenascin-C expression by vessels correlated with disease duration and appeared to be involved in vascular lesion pathology. Morphometric analysis showed that tenascin-C expression by small arteries is correlated with PG-M/versican expression in surrounding connective tissue. PG-M/versican was also present at the neointima of severely narrowed vessels. Although tenascin-C expression by synovial lining and connective tissue shows marked regional variation and seems inconsistent, in vitro examination suggested that tenascin-C production by these tissues is regulated in response to mechanical strain on the flexor tenosynovium.     

A comparison of flexor tenosynovectomy, open carpal tunnel release, and open carpal tunnel release with flexor tenosynovectomy in the treatment of carpal tunnel syndrome

The purpose of this study was to identify the advantages and disadvantages of performing a flexor tenosynovectomy without dividing the transverse carpal ligament, an open carpal tunnel release, and an open carpal tunnel release with flexor tenosynovectomy in the treatment of carpal tunnel syndrome. From 1990 to 1998, a retrospective study was done in which a flexor tenosynovectomy was performed in 133 patients without division of the transverse carpal ligament and compared with 68 patients who had an open carpal tunnel release and 75 patients who had an open carpal tunnel release and flexor tenosynovectomy. Patients were followed up for an average period of 30 weeks with history and physical findings and nerve conduction velocities and for an average period of 2.6 years with telephone interviews. There was a 2.3 percent incidence of pillar pain in the flexor tenosynovectomy group, which may explain the earlier return to their regular jobs at an average time of 9.9 weeks, compared with 10.7 weeks for the carpal tunnel release group and 12.0 weeks for the carpal tunnel release/flexor tenosynovectomy group. The latter two groups had an incidence of pillar pain of 12.1 percent and 25.3 percent, respectively. Postoperative grip strength was statistically significantly improved in the flexor tenosynovectomy group compared with the other two groups, where adjustments were made for sex and preoperative grip strengths with standard error of adjusted means. In the flexor tenosynovectomy group, 20.6 percent of patients had a previous open or endoscopic carpal tunnel release with recurrent carpal tunnel syndrome, compared with 5.2 percent in the open carpal tunnel release group and 21.6 percent in the open carpal tunnel release with flexor tenosynovectomy group. Excisional biopsies of flexor tenosynovium in the flexor tenosynovectomy, open carpal tunnel release, and open carpal tunnel release with flexor tenosynovectomy groups revealed an incidence of fibrosis in 89.2 percent, 88.9 percent, and 87.7 percent of specimens, respectively. Edema was a frequent finding, but an active inflammatory response was seldom seen. The findings in this study indicate that because of a significant decrease in pillar pain, a flexor tenosynovectomy in the treatment of carpal tunnel syndrome would likely benefit workers who use the palm of the hand in heavy manual or highly repetitive work by allowing them to return to regular duty sooner.     

Concomitant presentation of carpal tunnel syndrome and trigger finger

Background

Carpal tunnel syndrome (CTS) and trigger finger (TF) are common conditions that may occur in the same patient. The etiology of most cases is unknown. The purpose of this study was to evaluate the rate of concomitant occurrence of these two conditions at presentation and to compare the concomitant occurrence in normal and diabetic patients.

Methods

One-hundred and eight consecutive subjects presenting to our hand clinic with CTS and/or TF were evaluated. The existence of both of these conditions was documented through a standard history and physical examination. The definition of trigger finger was determined by tenderness over the A1 pulley, catching, clicking or locking. CTS was defined in the presence of at least two of the following: numbness and tingling in a median nerve distribution, motor and sensory nerve loss (median nerve), a positive Tinel's or Phalen's test and positive electrophysiologic studies.

Results

The average age of the participants was 62.2 ± 13.6 years. Sixty-seven patients presented with symptoms and signs of CTS (62%), 41 (38%) subjects with signs and symptoms of TF. Following further evaluation, 66 patients (61%) had evidence of concomitant CTS and TF. Fifty-seven patients (53% of all study patients) had diabetes. The rate of subjects with diabetes was similar among the groups (p = 0.8, Chi-square test).

Conclusion

CTS and TF commonly occur together at presentation though the symptoms of one condition will be more prominent. Our results support a common local mechanism that may be unrelated to the presence of diabetes. We recommend evaluation for both conditions at the time of presentation.     

Geometrical changes of knee ligaments and patellar tendon during passive flexion

Patterns of fibre elongation and orientation for the cruciate and collateral ligaments of the human knee joint and for the patellar tendon have not yet been established in three-dimensions. These patterns are essential for understanding thoroughly the contribution of these soft tissues to joint function and of value in surgical treatments for a more conscious assessment of the knee status. Measurements from 10 normal cadaver knees are here reported using an accurate surgical navigation system and consistent anatomical references, over a large flexion arc, and according to current recommended conventions. The contours of relevant sub-bundles were digitised over the corresponding origins and insertions on the bones. Representative fibres were calculated as the straight line segments joining the centroids of these attachment areas. The most isometric fibre was also taken as that whose attachment points were at the minimum change in length over the flexion arc. Changes in length and orientation of these fibres were reported versus the flexion angle. A good general repeatability of intra- and inter-specimens was found. Isometric fibres were found in the locations reported in the literature. During knee flexion, ligament sub-bundles slacken in the anterior cruciate ligament, and in the medial and lateral collateral ligaments, whereas they tighten in the posterior cruciate ligament. In each cruciate ligament the two compounding sub-bundles have different extents for the change in fibre length, and also bend differently from each other on both tibial planes. In the collateral ligaments and patellar tendon all fibres bend posteriorly. Patellar tendon underwent complex changes in length and orientation, on both the tibial sagittal and frontal planes. For the first time thorough and consistent patterns of geometrical changes are provided for the main knee ligaments and tendons after careful fibre mapping.     

The BGN and ACAN genes and carpal tunnel syndrome

The causes of idiopathic carpal tunnel syndrome (CTS) remain unknown and the involvement of the tendons within the carpal tunnel structure in the aetiology of CTS cannot be excluded. Variants within the COL5A1 gene, an important regulator of fibril assembly in tendons, have previously been associated with modulating the risk of CTS. Furthermore, proteoglycans are also important structural components of tendons and variants within the aggrecan gene are associated with musculoskeletal soft tissue injuries. The aim of this study was to determine whether ACAN and BGN variants are associated with CTS.     

The effect of provocative tests on electrodiagnosis criteria in clinical carpal tunnel syndrome

Introduction and objectiveNerve conduction study is the most sensitive test for diagnosis of carpal tunnel syndrome (CTS). This test is normal in some patients with mild CTS. Median nerve conduction study evaluation after a provocative test (e.g. wrist flexion) may be helpful for diagnosis of mild CTS. This study aimed to determine the effect of wrist flexion on median nerve conduction in patients suspected to CTS and in healthy subjects.Materials and methodsIn this case-control study, 20 patients (20 hands) with clinical signs of CTS and normal routine electrodiagnosis test results and 20 healthy subjects were investigated. Measured parameters included: median nerve distal sensory latency (DSL), nerve conduction velocity (NCV) across wrist, compound nerve action potential (CNAP), distal motor latency (DML) and compound muscle action potential amplitude (CAMPAMP). The above noted parameters were measured before and after 5 min of full wrist flexion. Data were analyzed using paired T-test.ResultsDistal sensory latency increment and NCV decrimental after 5 min of wrist flexion in the patients group were statistically significant (p < 0.01). The same parameters did not show significant incremental or detrimental changes in the control group.ConclusionMedian nerve DSL and NCV measurement after 5 min of wrist flexion may be helpful in determining more sensitive parameters in the electrodiagnosis of CTS.