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Biomedical subjects

D S Louis

Publications and source records attributed to D S Louis.

At least 73 records · Page 4Linked to original sources

Calcifying synovial sarcoma.

The presence of a calcified mass in the soft tissue may be the result of any number of processes. Post-traumatic changes and metabolic alterations may both lead to such calcification. The presence of calcification is much less commonly seen in malignant neoplasms. A case of calcifying synovial sarcoma with unusual features was recently seen.

Calcinosis↗

Giant cell tumour of the triquetrum.

A case of giant cell tumour involving the triquetrum is reported. Treatment consisted of resection of the triquetrum, followed by intercarpal arthrodesis.

Adult↗

Autogenous nerve pedicle graft in the forearm.

We report our experience during a 15-year period with three patients who had severe segmental loss of more than 10 cm of both the median and ulnar nerves in the arm and forearm. The procedure was described by St. Clair Strange and by Silverstone in 1947. A modification of the procedure was used in our three patients. In two patients, the proximal stumps of the median and ulnar nerves were sutured together in the proximal forearm. The ulnar nerve was transected high in the axilla, leaving its blood supply intact. Several months later the ulnar nerve was transposed distally, and a juncture with the distal median nerve was created. The third patient had a significant segmental loss in the arm of both the median and ulnar nerves. The distal stumps of the median and ulnar nerves were sutured together, and at a later stage the ulnar nerve was transposed proximally and sutured to the median nerve in the axilla. In all three patients, an advancing Tinel sign was observed. Subjectively, all three patients believed there was a definite improvement in sensibility. Objective testing was, however, less convincing. This operation has limited applicability but definitely has a place in situations where direct sutures or nerve grafting are impossible.

Adult↗

Postoperative toxic shock syndrome after reconstructive surgery of the hand.

Toxic shock syndrome is a devastating and potentially lethal complication, which can occur in postoperative patients. Our experience with toxic shock syndrome after a reconstructive procedure on the hand is reported. An awareness of the clinical and laboratory manifestations of toxic shock syndrome was needed to facilitate its early recognition and treatment.

Adult↗

Scaphoid-trapezium-trapezoid fusion in the treatment of chronic scapholunate instability.

Limited intercarpal arthrodesis for chronic scapholunate instability has been the subject of several recent publications. We have followed nine patients, who had scapho-trapezio-trapezoidal (S-T-T) fusion for scapholunate instability. All nine patients were re-examined recently after an average follow-up period of 19 months (range, 12 to 25 months). Six of the nine patients believed that their symptoms were significantly improved. The postoperative range of wrist motion (ROM) was decreased in all directions of motion. The pinch strength averaged 86% on the treated side and the grip strength averaged 74% of the unoperated side. Review of follow-up x-ray films showed radiographic evidence of union in eight of nine patients. We conclude that, with careful patient selection and close attention to operative detail, S-T-T fusion can be an effective treatment for scapholunate instability. However, the results are not uniformly predictable, and neither range of motion nor strength is normal after the procedure.

Adolescent↗

Arthrodesis of the wrist: past and present.

Arthrodesis of the wrist is a well established procedure that may be performed by a variety of techniques. The position of 10 degrees to 30 degrees of extension and 0 degree to 15 degrees of ulnar deviation is the most commonly accepted position for maximum hand function. Van Gemert has written an extensive monograph reviewing the results after wrist arthrodesis. He concluded that only 42% of 66 patients reviewed met all of the following desired criteria: bony union, subjective improvement of pain, improved power of grip and pinch, no loss of function in adjacent joints, and a good ergonomic score by the system that they used. A review of our cases of wrist arthrodesis shows many of the problems noted by Clendenin and Green. Our review also indicates that patients who make occupational transitions to less hand intensive activities have a better response to the procedure.

Arthrodesis↗

Dynamic radiographic evaluation of obscure wrist pain in the teenage patient.

Chronic wrist pain in the teenage patient constitutes a diagnostic challenge. Carpal instability patterns and internal joint derangements may be difficult to diagnose by physical examination and conventional plain radiographs. Dynamic radiographic studies frequently provide a better understanding of abnormal wrist mechanics. We reviewed our experience with fluoroscopy and radiocarpal arthrography in 14 teenage patients with chronic wrist pain. Videotape fluoroscopy was performed in all 14 patients. Dynamic radiocarpal arthrography was then performed in 10 patients in whom fluoroscopic findings were normal or more information was needed. These imaging methods led to a diagnosis in 64% of the patients and excluded a significant anatomic carpal abnormality in the other patients. In the teenage patient, internal derangements of the intercarpal ligaments are usually posttraumatic rather than attritional in origin. Dynamic radiographic techniques provide an accurate means for the diagnosis of these specific anatomic carpal abnormalities.

Adolescent↗

Cost effectiveness of wrist fluoroscopy and arthrography in the evaluation of obscure wrist pain.

The cost effectiveness of wrist fluoroscopy and arthrography was evaluated in patients with obscure wrist pain. Dynamic fluoroscopy was performed in 91 cases and was positive in 54 (59%). Radiocarpal arthrography was performed in 60 of these cases in which further information was desired. Arthrography increased the diagnostic yield to 62 of 91 cases (68%). Diagnoses included ligament and cartilage tears, and dynamic intercarpal instability. The cost per positive examination for fluoroscopy, based on total cost for fluoroscopy in 91 patients divided by number of positive cases, is $126. The cost per positive examination by arthrography alone is $377. When arthrography is done only when fluoroscopy is equivocal or negative, the cost per positive examination (fluoroscopy plus arthrography) drops to $280. Wrist arthrography is only cost effective if done after dynamic fluoroscopy fails to answer the clinical questions. When done together in this setting, the two procedures are most cost effective than arthrography alone. Based on current costs, conservative treatment of carpal instability costs about $1,500, and surgical therapy costs about $4,000. Thus, fluoroscopy and arthrography may further reduce the cost of management of obscure wrist pain by identifying those patients who would not benefit from surgical exploration.

Arthrography↗

Rupture and displacement of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb. Preoperative diagnosis.

The evaluation and treatment of injuries of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb remain controversial. In a retrospective study that was done to assess our ability to determine whether displacement of the ligament (a Stener lesion) was present, we reviewed our accumulated experience with patients who had an injury of this ligament who were treated surgically between 1972 and 1984. Since our method of evaluation changed in 1977, we compared the preoperative and operative diagnoses in the twenty patients who were treated surgically from 1972 through 1976 with those in the twenty patients who were so treated from 1977 through 1984. Considering all forty patients who were treated operatively, sixteen (40 per cent) had a typical Stener lesion, and in two others (5 per cent) the ulnar collateral ligament was rolled up on itself and lying beneath the adductor aponeurosis. From 1972 through 1976, stability was tested with the metacarpophalangeal joint in complete extension or in varying amounts of flexion. Of the twenty thumbs that were evaluated by this technique and were treated surgically, 20 per cent had a Stener lesion. From 1977 through 1984, stability was tested with the joint in full flexion because of the findings in anatomical studies that were completed in 1977; the incidence of a Stener lesion in the twenty thumbs that were treated by repair or reattachment of the ligament during this time was 70 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Cutaneous atrophy after corticosteroid injection.

Soft tissue inflammatory disorders can be treated by regional administration of corticosteroid preparations. However, the local catabolic effects of these agents can result in cutaneous atrophy and pigmentary changes. Since all injectable steroid agents may produce these adverse effects, corticosteroids must be used judiciously. The physician must be familiar with the chosen steroid and its recommended dosage.

Adrenal Cortex Hormones↗

Steady-state kinetic analysis of transcription of cloned tRNASer genes from Drosophila melanogaster.

Drosophila melanogaster Schneider II cells contain a factor which inhibits transcription in vitro of cloned tRNA genes in crude extracts made from these cells. The inhibitor could, however, be effectively neutralized by addition of certain non-template DNAs. In the absence of the transcription inhibitor activity, the steady-state kinetics of tRNA production from cloned genes followed one-substrate enzyme kinetics to a high degree of accuracy. Maximal rates of transcription and apparent affinity constants were analyzed for a collection of cloned D. melanogaster tRNASer genes. The stability of the complex formed by the transcription proteins and the template DNA was found to be nearly constant for the genes examined. The transcription rates, however, were greatly influenced by the DNA sequences flanking the tRNA genes. Analysis of transcription competition between DNA templates showed pure competitive behavior. Inhibition constants derived from these experiments indicated that the formation of the transcription complex was affected by sequences flanking the tRNA genes. Furthermore, the rate-limiting step in complex formation was independent of the stability of the final form of the complex.

Cloning, Molecular↗

Long-term follow-up of nonvascularized fibular autografts for distal radial reconstruction.

Three patients with giant cell tumors of the distal radius had en bloc excision of the distal radius and replacement with the ipsilateral fibula. Two of the patients were followed for 16 years and one for 14 1/2 years. Forearm rotation, as well as wrist motion, was limited in all three patients, yet they remained functional and pain free except during periods of prolonged or excessive use. All three patients were pleased with the results. Bone union occurred primarily in all three patients without a supplemental bone graft or microvascular anastomosis. This method has a definite place in the hand surgeon's armamentarium when compared with radial allografts and microvascular free fibular translocation.

Adult↗

Lipofibromas of the median nerve: long-term follow-up of four cases.

Four cases of lipofibromatous infiltration of the median nerve with long-term follow-up (average 11 years) are reported. Progressive compromise of median nerve function has been noted. Initial treatment considerations should be directed toward biopsy and alleviation of the compression neuropathy. The role of microsurgical debulking procedures remains unclear at this time.

Adolescent↗

The upper extremity and psychiatric illness.

Thirty-three patients who had various conversion reactions manifested by signs and symptoms involving the upper extremities were seen over a 13-year period. Factitious lymphedema, factitious ulcers, clenched fists, as well as other dysfunctional postures of the hand and upper extremity, were the most frequently recognized patterns of illness. Denial of knowledge of the cause of the physical problem and a lack of insight into the illness are major parts of the disease process. Twenty-nine of the 33 patients in this study had work-related and therefore compensable injuries. The physical signs and symptoms resolved in four of the patients when compensation was withdrawn. The average follow-up in this study was 4 1/2 years. Unfortunately, the long-term follow-up of these patients revealed that this disease process was chronic and most frequently failed to resolve. Various efforts at treatment have been unsuccessful, including extensive psychotherapy. Confrontation with the patient is contraindicated.

Adolescent↗

Fluoroscopic and arthrographic evaluation of carpal instability.

The efficacy of a diagnostic protocol involving videotape fluoroscopy of carpal motion and radiocarpal arthrography was evaluated in patients with wrist pain unexplained by physical examination and conventional radiographs. Videotape fluoroscopy was performed as the first study in 68 consecutive cases and was positive in 44 (66%). Radiocarpal arthrography was performed after videotape fluoroscopy in 39 of the cases (57%), including the 24 in which videotape fluoroscopy was normal and 15 others in which further information was desired in spite of positive videotape fluoroscopy. The addition of radiocarpal arthrography to videotape fluoroscopy increased the diagnostic yield to 52 (76%) of the 68 cases and excluded significant anatomic or dynamic abnormality in the others. The diagnosis was proven surgically in 25 cases. This protocol was efficacious for ligament tears of the proximal carpal row, triangular fibrocartilage tears, and proximal and midcarpal instability. Videotape fluoroscopy should be the primary method of evaluating patients with unexplained wrist pain, and arthrography should be done in those cases in which fluoroscopy is either normal or does not fully explain physical findings.

Adolescent↗