Kuo-Chen Wu

An Ultrasonographic and Anatomical Study of Carpal Tunnel, with Special Emphasis on the Safe Zones in Percutaneous Release

We examined 40 wrists of 12 embalmed and eight fresh cadavers and defined the relative position of the flexor retinaculum to the neurovascular structure, ultrasonographic markers and safe zones by ultrasonography and anatomical dissection. Both longitudinal and transverse ultrasonographic sections clearly depicted the flexor retinaculum, neurovascular bundles, median nerve, flexor tendons and bony boundaries of the underlying joints. Topographic measurement showed [i] good correlation between the actual extent of the flexor retinaculum and the ultrasonographically determined distance between bony landmarks in all hands, and [ii] the widths and lengths of well-defined safe zones. A comparison study confirmed the accuracy of ultrasonography. We conclude that these ultrasonographic landmarks can locate the flexor retinaculum and facilitate safe and complete carpal tunnel release with open or minimally invasive techniques.

Effects of topical corticosteroids on the sciatic nerve: an experimental study to adduce the safety in treating carpal tunnel syndrome

Despite known detrimental effects on the blood flow and histology of nerves after intraneural corticosteroid injection, the neurotoxic effect of corticosteroids remains unclear. We investigated the effect of topical dexamethasone on nerve function. Two sponge strips soaked with dexamethasone at doses of 0.8, 1.6, and 3.2 mg were placed under and over the left sciatic nerve of adult Wistar rats for 30 minutes. Mixed-nerve-elicited somatosensory evoked potentials and dermatomal somatosensory evoked potentials were evaluated immediately and repeated together with functional tests and histology 2 weeks later. Evoked potential amplitude was dose-dependently lower and latency was prolonged in dexamethasone-treated sciatic nerves compared to controls. The suppression persisted with incomplete recovery for at least 4 hours, but differences between treated and control nerves were not significant after 2 weeks. Topical dexamethasone adversely affected neural conduction in a dose-dependent manner. Our results suggest that caution is required when using large doses of corticosteroid for injection of the carpal tunnel.

A Cadaveric and Preliminary Clinical Study of Ultrasonographically Assisted Percutaneous Carpal Tunnel Release

The aim of this study was to assess the effectiveness and safety profile of a new technique for ultrasonographically assisted percutaneous carpal tunnel release. Experiments were performed on 40 hands in 20 cadavers. We first performed a detailed ultrasonographic examination and correlation study that included surgical dissection of the transverse carpal ligament, the related neurovascular structures and the bony landmarks of the radiocarpal, midcarpal and carpometacarpal joints of the right hand. We then used the measurements we made for percutaneous carpal tunnel release of the transverse carpal ligament using intra-operative ultrasonography for guidance and a hook knife on the left-hand side. The completeness of the release and the potential risks of injury to the flexor tendon and neurovascular bundles were examined. Using real-time intra-operative ultrasonographic monitoring to clearly delineate these targets, we were able to percutaneously release the transverse carpal ligament completely in 18 (90%) of the 20 hands and partially release it in 2 without injuring any neurovascular bundles. We then performed the procedure on 91 consecutive cases of carpal tunnel syndrome and found that the sensory disturbances disappeared in 100% patients 12 mo post-operatively; only 2 hands were graded as unsatisfactory. There were no intra- or post-operative complications. Based on the results from the cadaveric studies and our successful preliminary clinical outcomes, we conclude that this method is tolerable and that its clinical application can be encouraged.

Inflammation is present in de Quervain Disease--correlation study between biochemical and histopathological evaluation

BackgroundDe Quervain disease is a stenosing condition of the sheath of the abductor pollicis longus and extensor pollicis brevis tendons at the radial styloid process. Previous studies consistently reported that the pathological change of this condition is thought to be primarily an extensor retinaculum thickened by fibrosis and angiogenesis instead of inflammation. Contradictorily, the conservative treatment for de Quervain disease is anti-inflammatory medication. The inflammatory response may be involved in this disease; however, there is no present study directly evidencing whether the inflammatory responses exist in de Quervain disease or not. The histopathology of de Quervain disease is yet to be elucidated clearly. PurposeTo grade all specimens in the different stages and characterize specific inflammatory cell and factors to examine whether inflammatory response is involved in de Quervain disease. MethodsRetinaculum samples were collected from 13 patients with de Quervain disease after surgery. The specimens were evaluated histologically by collagen structure grading and immunohistochemically by quantifying the presence of neutrophil elastase, macrophages, cyclooxygenase, and vascular endothelium. ResultsNeutrophil elastase and cyclooxygenase occur in the de Quervain disease retinaculum and increased with the grade of collagen structure. After angiogenesis, macrophage infiltration occurs in the grade II matrix worse than grade III matrix. ConclusionsInflammation is present in de Quervain disease. This study provides direct evidence for inflammatory cell and infiltration factors and offer valuable clues for specific pharmacological therapies for de Quervain disease.

The assessment of the ulnar nerve at the elbow by ultrasonography in children

We evaluated the morphological changes to the ulnar nerve of both elbows in the cubital tunnel by sonography in a total of 237 children, of whom 117 were aged between six and seven years, 66 between eight and nine years, and 54 between ten and 11 years. We first scanned longitudinally in the extended elbow and then transversely at the medial epicondyle with the elbow extended to 0 degrees . We repeated the scans with the elbow flexed at 45 degrees , 90 degrees , and 120 degrees . There were no significant differences in the area of the ulnar nerve, but the diameter increased as the elbow moved from extension to flexion in all groups. More importantly, the ulnar nerve was subluxated anteriorly on to the medial epicondyle by 1.5% to 1.9% in extended elbows, by 5.9% to 7.9% in those flexed to 45 degrees , by 40.0% to 44% in those flexed to 90 degrees , and by 57.4% to 58.1% in those flexed to 120 degrees , depending on the age group. Sonography clearly and accurately showed the ulnar nerve and was useful for localising the nerve before placing a medial pin. Because the ulnar nerve may translate anteriorly onto the medial epicondyle when the elbow is flexed to 90 degrees or more, it should never be overlooked during percutaneous medial pinning.

A compound heterozygous mutation of CYP27A1 gene in a Taiwanese patient with cerebrotendinous xanthomatosis

Abstract Cerebrotendinous xanthomatosis (CTX, OMIM: 213700) is a rare inherited autosomal recessive lipid storage disorder with multiple system involvement. The disease is caused by mutations in the gene encoding sterol 27-hydroxylase (CYP27A1), leading to a block in bile synthesis, with accumulation of substrates for this enzyme, including cholesterol, resulting in an increase in the conversion of cholesterol to cholestanol. Clinically, CTX is characterized by tendon xanthomas, juvenile cataracts, premature atherosclerosis, and progressive neurological deficits [1]. We report the mutation analysis of a Taiwanese patient with CTX involving only the Achilles tendon.

The Estrogen Receptor-β Expression in De Quervain's Disease.

Stenosing tenosynovitis of the first dorsal compartment of the wrist (a.k.a. de Quervain’s disease) is common but how estrogen is involved is still unknown. We previously reported that inflammation was involved in the pathogenesis of this ailment. In the present study, we extended our investigation of estrogen receptor (ER)-β expression to determine whether estrogen is involved in the pathogenesis of de Quervain’s. Intraoperative retinaculum samples were collected from 16 patients with the ailment. Specimens were histologically graded by collagen structure and immunohistochemically evaluated by quantifying the expression of ER-β, interleukin (IL)-1β and IL-6 (inflammatory cytokines), cyclooxygenase (COX)-2 (an inflammatory enzyme), and vascular endothelial growth factor (VEGF), and Von Willebrand’s factor (vWF). De Quervain’s occurs primarily in women. The female:male ratio in our study was 7:1. We found that ER-β expression in the retinaculum was positively correlated with disease grade and patient age. Additionally, disease severity was associated with inflammatory factors—IL-1β and IL-6, COX-2, and VEGF and vWF in tenosynovial tissue. The greater the levels of ER-β expression, tissue inflammation, and angiogenesis are, the more severe de Quervain’s disease is. ER-β might be a useful target for novel de Quervain’s disease therapy.

Sonographically Assisted Percutaneous Removal of Screws in Dynamization of the Interlocking Intramedullary Nail

Dynamization is a method of removing the interlocking screw(s) farthest from the fracture site for improving healing in femoral and tibial fractures that show delayed healing after static interlocking nailing. We describe a simple sonographically assisted technique for percutaneous dynamization of deep‐seated impalpable screws.

Effects of Different Dosage of Dexamethasone on Behavioral, Electrophysiological, and Histomorphological Recovery in a Chronic Sciatic Nerve Compression Model

OBJECTIVE To investigate the effects of different doses of topical dexamethasone (Dex) on sciatic nerves with simulated compressive neuropathy. METHODS Thirty-two Wistar rats were divided into four groups of 8: Sham group: no compression of the sciatic nerve + no treatment; Saline: chronic compression of the left sciatic nerve for 4 weeks + saline; 0.8% Dex: chronic compression + 0.8 mg of Dex; 3.2% Dex: chronic compression + 3.2 mg of Dex. Two sponge strips soaked with saline or Dex were placed under and over the nerve for 30 min in both Dex groups. Mixed-nerve-elicited somatosensory evoked potentials (M-SSEPs) and compound muscle action potentials (CMAPs) were measured to verify the compressive neuropathy in post-treatment follow-up. Behavioral observations of thermal hyperalgesia tests were quantified before electrophysiological examinations. Treated and contralateral nerves were harvested for histomorphological analysis. RESULTS M-SSEP and CMAP amplitudes significantly decreased and latencies were significantly prolonged on postcompression thermal hyperalgesia tests. Rats in both Dex groups showed significant improvement in both sensory and motor conductive values and in neurological function, as well as increased mean myelin diameter on the final histomorphological examination. For rats in the saline group, these parameters showed incomplete recovery compared with the Sham group and the precompression baseline. Moreover, the changes after Dex treatment were not dose-dependent. CONCLUSIONS Topical Dex reversed electrophysiological, behavioral, and structural changes in chronically compressed sciatic nerves. Differences between the beneficial effects of high-dose and low-dose Dex were nonsignificant.

Synovial fluid biomarkers: association with chronic rotator cuff tear severity and pain

BACKGROUND We tested the hypothesis that biomarkers in the synovial fluid of the glenohumeral (shoulder) joint are correlated with visual analog scale (VAS) scores, functional scores, and ultrasound findings of chronic rotator cuff tear (RCT) severity. METHODS We measured biomarkers in shoulder joint synovial fluid of 42 patients with partial-thickness (21), nonmassive full-thickness (10), and massive full-thickness (11) RCTs. Pain duration, tear severity, and VAS and functional scores were compared with interleukin (IL) 1β, IL-6, matrix metalloproteinase (MMP) 1, and MMP-13 levels. RESULTS Both MMP-1 and MMP-13 levels were significantly highest in the massive full-thickness group. MMP-13 levels were significantly different between groups, but proinflammatory cytokine IL-1β and IL-6 levels were not. However, IL-1β levels were significantly positively correlated with VAS (r = 0.66; P <.01) and functional scores (r = 0.61; P <.01), but IL-6, MMP-1, and MMP-13 levels were not. CONCLUSIONS IL-1β levels in shoulder synovial fluid correlated positively with shoulder pain and functional scores in patients with chronic RCTs. Both MMP-1 and MMP-13 levels were altered and increased with cuff tear severity.