PubMed Health⌕ Search

Biomedical subjects

C A Laurin

Publications and source records attributed to C A Laurin.

At least 19 recordsLinked to original sources

Gluteal nerve damage following total hip arthroplasty. A prospective analysis.

Injuries to the peroneal or tobial divisions of the sciatic nerve occur in approximately 0.7-7.6% of patients undergoing total hip arthroplasty. No prior studies have investigated the incidence of injury to the superior or inferior gluteal nerves during hip surgery. This study evaluates the incidence of injury to the superior and inferior gluteal nerves in 55 patients undergoing total hip arthroplasty using a newly devised EMG scoring system. Subclinical gluteal nerve injury was documented in over 77% of patients, whether a posterior or a lateral approach to the hip was used.

Adult↗

Gaucher disease: accurate identification of asymptomatic French-Canadian carrier using nonlabeled authentic sphingolipid substrate N-palmitoyl dihydroglucocerebroside.

Gaucher disease is an autosomal recessive sphingolipidosis associated with deficient glucocerebroside beta-glucosidase activity. It is a panethnic metabolic disorder, but the carrier frequency is particularly high among Ashkenazi Jews (estimated between 1:12-1:25). In order to establish a reliable and convenient biochemical assay method for differentiating asymptomatic Gaucher carriers from normal individuals, glucocerebroside beta-glucosidase activity was determined in peripheral blood lymphocytes and cultured skin fibroblasts of 11 Gaucher obligate heterozygotes using the authentic nonlabeled sphingolipid substrate N-palmitoyl dihydroglucocerebroside and the artificial fluorogenic substrate 4-methylumbelliferyl-beta-D-glucopyranoside (4MUGP). The level of lymphocyte beta-glucosidase activity on the glucocerebroside substrate was observed to range from 42-65% of that of the control mean, and there was no overlap of enzyme activity between the Gaucher heterozygotes and controls. However, when the artificial fluorogenic substrate 4MUGP was used, the level of beta-glucosidase activity in 2 of the Gaucher obligate heterozygotes was noted to overlap with that of the control individuals. Contrary to findings in the lymphocytes, cultured skin fibroblasts appear to be a reliable enzyme source for Gaucher carrier detection even when the artificial fluorogenic 4MUGP substrate was used, as the level of beta-glucosidase activity in all of the Gaucher obligate heterozygotes tested was intermediate and distinctly separated from that of the control persons. Using the lymphocyte glucocerebroside beta-glucosidase assay and fibroblast 4MUGP beta-glucosidase assay methods, we identified the carrier status in 3 other relatives and ruled it out in 4 others. These data suggest that nonlabeled glucocerebroside is a reliable and highly specific substrate for either lymphocyte or fibroblast beta-glucosidase activity assay in identifying asymptomatic Gaucher carriers. Use of the 4MUGP substrate for differentiating Gaucher heterozygotes from control persons, on the other hand, should be restricted to the fibroblast enzyme assay method, as considerable overlap of enzyme activity was noted in lymphocytes.

Adult↗

Rate of mortality for elderly patients after fracture of the hip in the 1980's.

At an average follow-up of 2.1 years, we reviewed the records of 241 patients who had had a fracture of the hip. The average age of the patients was 75.4 years. The rate of mortality one year after the fracture was 21.6 per cent for the total group, 8.0 per cent for the low-risk group, and 49.4 per cent for the high-risk group. The standard mortality ratio was six times higher for the high-risk group than for the general population (individuals who did not have a fracture), matched for age. It was highest for patients who were less than seventy years old and lowest for those who were older than eighty. However, in the second year after the fracture, the standard mortality ratio approached unity--that is, the rate of mortality approached that of the general population. The results suggest that there is an inverse relationship between mortality and advanced age and that the impact of a fracture of the hip on mortality is seen primarily in the first year after injury.

Adult↗

Fractures of the ring of the axis. A classification based on the analysis of 131 cases.

The retrospective analysis of 131 patients suffering from a fracture of the ring of the axis is reported. The injury was classified into three types according to radiological displacement and stability. Associated injuries and neurological deficit are discussed and a theory of pathogenesis presented. Guidelines for the management of each type of fracture are proposed.

Adolescent↗

Metatarsophalangeal fusion for hallux valgus: indications and effect on the first metatarsal ray.

Arthrodesis of metatarsophalangeal joint was performed in 31 cases of severe hallux valgus. With the surgical technique used, which is described in detail, internal fixation and plaster cast immobilization were not necessary. Analysis of the results suggested that the operation is indicated for severe deformities in elderly patients, preferably women. The basic metatarsal deformity was corrected by the procedure.

Adult↗

[A study of the tensile strength of cruciate ligaments with regard to the possibilities of prosthetic replacement (author's transl)].

Recent clinical and experimental results in the prosthetic replacement of the anterior cruciate ligament are minimal and this fact has incited us to search for additional fundamental characteristics of natural and synthetic ligaments. The dissection of over 30 human knees (5 fresh and 27 embalmed specimens), of 50 dog knees and of 20 cat knees showed that the posterior cruciate ligament was longer and of bigger size than the anterior cruciate ligament. In dogs, the anatomo-radiological study showed a lenghtening of 14,4 p. 100 for the anterior cruciate and of 10,5 p. 1u0 for the posterior cruciate ligament in the various goniometric positions. Traction with the Instron apparatus using whole knee with preserved bony attachments revealed an elastic resistance (yield point) of the ligament of about 50 kg, 60 kg and 30 kg (for human, dog and cat respectively) with elastic elongation (at the yield stress) of 25 p. 100, 35 p. 100 and 45 p. 100 (respectively). Trials on the polyethylene prosthetic ligament used at the present time for replacement of cruciate ligaments in humans showed an elastic resistance of only 16 kg with an elasticity of only 1,4 p. 100. The major differences between the physical properties of the artificial and natural ligaments that we have studied in experimental conditions incite our serious doubt as to the value for the practical use of such a prosthesis and provoque strongly the necessity of search for alternative synthetic or other material more suitable for the task in question.

Animals↗

The tangential x-ray investigation of the patellofemoral joint: x-ray technique, diagnostic criteria and their interpretation.

The X-ray technique for the tangential visualization of the patellofemoral joint is described; 3 X-ray signs (patellofemoral angle, patellofemoral index and patellofemoral displacement) are proposed as diagnostic aids in cases of subluxation of the patella and chondromalacia patellae. Theoretically, the pathogenesis of chondromalacia patellae and patellofemoral osteoarthritis may be explained as manifestations of cartilage damage secondary to lateral patellofemoral hyperpressure and medial patellofemoral hyperpressure.

Cartilage Diseases↗

The abnormal lateral patellofemoral angle: a diagnostic roentgenographic sign of recurrent patellar subluxation.

On roentgenograms made with the patient supine, the knees flexed 20 to 30 degrees, the x-ray tube between the ankles, and the cassette held proximal to the knees and perpendicular to the x-ray beam, it was found that a line between the femoral condyles and a line between the margins of the lateral facet of the patella formed the lateral patellofemoral angle, an angle that was of diagnostic value in patients with subluxation of the patella. In 100 clinically normal patients, these lines were parallel in three and formed an angle open laterally in ninety-seven. In thirty patients with subluxation of the patella, the lines were parallel in twenty-four and formed an angle open medially in six. In 100 patients with chondromalacia of the patella, however, the roentgenographic study was of no diagnostic value since the lines were parallel in ten and formed an angle open laterally in ninety.

Female↗

Prosthetic replacement of the anterior cruciate ligament in dogs.

Prosthetic cruciate ligaments are now used clinically. Long-term results are not yet available and for that reason an attempt has been made to reproduce the clnical situation in dogs. Post-traumatic osteoarthritis was inevitably noted following simple excision of the anterior cruciate ligament in a control group of 10 animals. Different prosthetic materials were used and their breaking point was compared with that of normal anterior cruciate ligaments. The longest follow-up period was 6 months. Although some animals had no clinically demonstrable instability, at autopsy all prosthetic ligaments were noted to have failed. The degree of post-traumatic osteoarthritis was directly related to the duration of follow-up. The causes of failure of the prosthetic ligament do not appear to be related to the method of anchorage to bone but rather to the type of prosthetic material used. Although the tensile strength may occasionally have been sufficient, the materials did not have the required elastic characteristics to meet the physiologic demands of a normal cruciate ligament.

Animals↗