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Biomedical subjects

P M Weeks

Publications and source records attributed to P M Weeks.

At least 19 recordsLinked to original sources

Relation of preoperative nerve-conduction values to outcome in workers with surgically treated carpal tunnel syndrome.

Ninety-three workers having undergone carpal tunnel decompression were assessed 16 to 100 months after surgery. The results of outcomes pertaining to symptoms of numbness, nocturnal awakening, and pain as well as job status were compared to the patients' preoperative nerve conduction study findings. Significant differences in preoperative nerve-conduction values (NCVs) were found between groups reporting poor results and those reporting good results. These differences were such that those reporting poor results had more normal NCVs. Those reporting job changes because of carpal tunnel syndrome also had more normal preoperative nerve-conduction results. Data indicate that those with terminal latencies 1 ms greater than the testing facility normal value or with sensory conduction velocity 10 ms less than the facility norm were more likely to benefit from surgery. This study suggests the need for caution when considering carpal tunnel surgery in workers with normal or near normal nerve-conduction results.

Adult↗

Carpal tunnel surgery outcomes in workers: effect of workers' compensation status.

One hundred thirteen workers' compensation and 53 non-workers' compensation patients who had undergone open carpal tunnel release were queried about job status and the presence or absence of residual symptoms of numbness, pain, or nocturnal awakening an average of 42 months postoperatively. Thirty-nine non-workers' compensation subjects were at their original jobs as compared to only 53 workers' compensation subjects. Seventeen of the workers' compensation subjects were unemployed versus two non-workers' compensation subjects. These differences were significant. Of patients changing jobs, 39 workers' compensation subjects and 2 non-workers' compensation subjects attributed their job change to symptoms of carpal tunnel syndrome. Residual symptoms were significantly more common in workers' compensation compared to non-workers' compensation subjects, with 92 of the former and 26 of the latter subjects reporting some residual symptoms.

Adult↗

The role of bone scintigraphy in diagnosing reflex sympathetic dystrophy.

Three-phase bone scintigraphy is used often to diagnose reflex sympathetic dystrophy of the hand. This study presents an analysis of the literature relating three-phase bone scanning to reflex sympathetic dystrophy in the upper extremity. The data show a wide variability in scintigraphic accuracy in patients with clinically obvious reflex sympathetic dystrophy. The results of bone scintigraphy correlate best with the clinical diagnosis of reflex sympathetic dystrophy within the first 20-26 weeks of onset. Even then, the sensitivity in the most recent series approximates 50%. After 26 weeks, there is a poor correlation between three-phase bone scanning and reflex sympathetic dystrophy. Consequently, three-phase bone scintigraphy should not be used as a major criterion in diagnosing reflex sympathetic dystrophy. The diagnosis of reflex sympathetic dystrophy remains a clinical diagnosis made by an experienced hand surgeon.

Bone and Bones↗

The regulation of collagen in fetal skin wounds: mRNA localization and analysis.

The deposition of collagen in fetal skin wounds has been shown in several animal models. The authors used a radiolabeled RNA antisense probe, complementary to the mRNA for the alpha-1 chain of human procollagen type I, to assess regulation of this collagen species in fetal and adult rabbit wounds. Dorsal skin wounds were placed on fetal and maternal animals at the beginning of the third trimester, and were harvested 3, 5, and 7 days later. In situ RNA/RNA hybridization was performed on suitable specimens, and morphometric analysis was carried out with a computerized LECO image analyzer. Fetal wounds exhibited an inflow of mesenchymal cells that produced collagen type I at levels higher than the surrounding tissue; this activity was highest on days 3 and 5 after wounding. Adult wounds had increased fibroblast presence by day 7, producing collagen type I at levels higher than those of adjacent unwounded tissue. Morphometric analysis of the signal produced by in situ hybridization and of the number of cells producing the signal in a given field showed that fetal wounds appear to produce collagen type I by an increase in the number of cells in the area of the wound--not by induction of the gene for procollagen type I. In contrast, adult wounds had both fibroblast migration and induction of procollagen type I mRNA synthesis. These findings imply multilevel regulation of collagen production in the adult and posttranslational regulation in the fetus.

Animals↗

The expression of transforming growth factor type beta in fetal and adult rabbit skin wounds.

Transforming growth factor, subtype beta (TGF-beta) exists in several isoforms and is known to have important roles in adult wound healing by promoting collagen and extracellular matrix component deposition. It is also believed that TGF-beta influences normal developmental processes during embryo-genesis. Immunolocalization of two isoforms, TGF-beta 1 and TGF-beta 2, in healing fetal and adult rabbit skin wounds shows distinctly different forms of expression of these molecules. TGF-beta 1 and TGF-beta 2 are both expressed within the developing fetal dermis, but no differential upregulation in the area of the healing wound is noted. In contrast, the expression of TGF-beta 1 and TGF-beta 2 is increased in adult wounds by day 7 after wounding, within macrophages that are abundant by this time. High levels of TGF-beta 1 and TGF-beta 2 within adult wounds might indicate that the relative paucity and differential distribution of these factors in fetal wounds are important in the production of scar in adults and the absence of scar in the fetus. Further, these patterns of expression suggest fundamental differences between fetal and adult tissues in accomplishing wound repair.

Animals↗

Hand injuries.

A systematic approach to the injured hand has been presented that ensures no injuries are overlooked and provides the basis for a reconstructive approach. This scheme is tissue oriented, first evaluating injury to the vasculature, then to the skin, bone, joint, nerve, and tendon units. The most complex injuries can be thoroughly evaluated and properly treated with this method.

Amputation, Traumatic↗

Traumatic pseudoaneurysm in an ulnar artery vein graft.

Ulnar artery thrombosis is well reported but treatment recommendations still vary. We report the 10-year follow-up of a vein graft used to treat a patient with ulnar artery thrombosis. The graft remained patent until the tenth year, when the patient sustained a blunt hyperextension injury to the involved wrist and developed a pseudoaneurysm of the vein graft. The pseudoaneurysm was found to be in the graft itself and not at the anastomosis. The vein graft thrombosed and was successfully treated with resection of the thrombosed vessel, embolectomy of the superficial palmer arch, and replacement with a new vein graft.

Adult↗

Plastic surgery applicants in 1992.

All the applicants to plastic surgery residency programs who participated in the residency matching program for 1992 were reviewed. Data were collected on age, sex, race, nationality, place of birth, undergraduate education, medical education, postgraduate training, research activity, and evaluation scores. Findings indicate that applicants interested in academic careers are significantly more likely to have published research and are generally rated higher in categories of intellectual curiosity, performance, and intelligence by evaluators. Women and some minorities were underrepresented when compared with recent medical school graduating classes. We recommend a longitudinal study of applicants to correlate career achievement with applicant characteristics. We also recommend some changes in the application and evaluation process and in efforts to interest women and minorities in the specialty.

Adult↗

Giant lipomas of the hand and forearm.

Giant lipomas of the upper extremity are infrequently reported. They can alter function by restricting motion or producing compressive neuropathies. This report of four cases of giant lipoma in the hand and forearm illustrates these functional losses. The role of MRI and CT in preoperative evaluation of these lesions is discussed and a report of an anterior interosseous syndrome caused by a giant lipoma is presented.

Adult↗

Occurrence and localization of transforming growth factor-beta (TGF-beta 1, beta 2) during rabbit skin development.

The expression of (TGF beta-1) and (TGF beta-2) in adult, fetal, and neonatal rabbit skin has been analyzed by immunohistochemistry. Samples were collected from the backs of fetal rabbits (23 and 30 days of gestation), newborn rabbits (1 day post-partum) and adult pregnant and nonpregnant rabbits. Forty samples were studied. To identify TGF-beta two antibodies were used: (RAB4) and (CL-B1/29). TGF-beta 1 and TGF-beta 2 displayed distinct distribution and intensity of staining at different stages of development. TGF-beta 1 was present in fetal skin (23 days of pregnancy) expressing abundant staining in cells within epidermis, dermis and hypodermis. Fetal skin (30 days of pregnancy) exhibited weak staining for TGF-beta 1; only isolated dermal cells in close proximity to hair follicles and sweat glands expressed intracellular staining. Newborn rabbit skin showed low expression for TGF-beta 1, around hair follicles and sweat glands. In contrast adult pregnant and non-pregnant rabbit skin exhibited abundant staining for TGF-beta 1 in epidermis, papillary dermis, around hair follicles, sweat glands, and blood vessels, no difference was observed among pregnant and non-pregnant rabbits. TGF-beta 2 was detected in all specimens and the distribution and intensity of staining were similar to those found for TGF-beta 1 in all groups. Our findings demonstrate that the expression of TGF-beta 1 and TGF-beta 2 is intense during early stages of rabbit skin development when morphogenesis is taking place and skin appendages are being formed; and less intense when these structures are formed and skin growth predominates. These results suggest an important role for TGF-beta 1 and TGF-beta 2 in rabbit skin development, probably regulating morphogenesis and growth.

Aging↗

Fascicular topography of the median nerve: a computer based study to identify branching patterns.

This study was undertaken to definitively describe the internal anatomy of the median nerve. Thirty median nerves were dissected in the distal forearm and hand. Sixteen nerves were sectioned every 250 to 1000 microns along their length. Computer programs were developed in our laboratory to digitize and store the data. Analysis of our data has shown the following consistent findings: (1) the number of fascicles remains relatively constant over the centimeter lengths of the nerve; (2) over 75% of the sections contain zero to one fascicular branching; (3) fascicular groups destined for the same endpoint remain localized within the nerve for long distances; and (4) calculation of Wilks' lambda demonstrates a high degree of group fascicular regionality.

Humans↗

Coincident rupture of the scapholunate and lunotriquetral ligaments without perilunate dislocation: pathomechanics and management.

Wrist injuries causing coincident disruptions of the scapholunate and lunotriquetral ligaments commonly result in perilunate dislocations. This article (1) describes our management of eight patients with wrist pain after coincident scapholunate and lunotriquetral ligament disruptions in the absence of perilunate dislocation; and (2) reports the results of biomechanical testing of some of the extrinsic and intrinsic wrist ligament and interprets these data to explain the injury seen clinically. The diagnosis of ligament failure was made on the basis of history, physical examination, arthrography and surgical exploration. Surgical treatment of seven patients consisted of concomitant scapho-trapezio-trapezoid fusion and lunotriquetral fusion. Three of seven patients were free of pain, two had pain only at the extremes of motion, and two required additional surgery. Biomechanical analysis of the scapholunate and lunotriquetral ligaments and two extrinsic wrist ligaments, the radiolunotriquetral and the radioscaphocapitate, confirmed the clinical suspicion that the intrinsic ligaments could be completely disrupted while the extrinsics are only partially injured. Such a scenario could account for the residual stability that prevents the development of perilunate dislocations. Coincident disruption of the scapholunate and lunotriquetral ligaments in the absence of perilunate dislocation is an unusual injury. Treatment with lunotriquetral fusion and scapho-trapezio-trapezoid fusion restored functional use in five of seven wrists while maintaining wrist motion.

Adult↗

Wrist pain: a systematic approach to diagnosis.

Numerous radiographic procedures are now available to help determine the cause of wrist pain. This paper presents a wrist-pain algorithm that defines the relative roles of various radiographic techniques in the evaluation of patients with wrist pain. Practical application of the algorithm is demonstrated through illustrative cases.

Adult↗

Management of chronic lunotriquetral ligament tears.

Treatment of chronic disruptions of the lunotriquetral (LT) ligament is not well-defined. Eleven patients treated by LT fusion with use of a compression screw are reported. The injury frequently resulted from hyperextension of the wrist. Pain on the ulnar side of the wrist, limited motion, and tenderness over the LT joint exacerbated by ballottement were present. Standard radiographs were normal. Arthrography showed the ligamentous tear in all cases. After operation, immobilization was continued until fusion was apparent radiographically. Fusion was achieved in all cases between 2 and 5 months. Four patients were free of pain, four patients had pain only at the extremes of motion, and three patients had persistent pain. Mean wrist motion was as follows (preoperative/postoperative): flexion (53 degrees/45 degrees), extension (60 degrees/49 degrees), radial deviation (17 degrees/21 degrees), and ulnar deviation (25 degrees/18 degrees). Maximum grip strength as a percentage of the uninjured side was 73% preoperatively and 59% postoperatively. LT tears can exist de novo or as part of the ulnar impaction syndrome; a method for differentiation is presented.

Adult↗