Biomedical subjects

L P Jorn

Publications and source records attributed to L P Jorn.

7 recordsLinked to original sources

PubMed2000

Hydroxyapatite-enhanced tibial prosthetic fixation.

Sixty-two knees (60 patients) were randomized to four noncemented groups. In Groups 1, 3, and 4, the bone cuts were made with a cooled saw blade. In Group 1, 15 patients were operated on with the porous coated Osteonic 7000 tibial component. In Group 2, 15 patients were operated on with the same tibial component as in Group 1 but with the use of a standard saw blade. In Group 3, 16 patients were operated on with the hydroxyapatite-coated Osteonic tibial component, and in Group 4, 16 patients were operated on with the hydroxyapatite Duracon tibial component. All patients were followed up clinically and with roentgenstereometric analysis. There were no differences among the groups regarding clinical outcome. One knee was revised (Group 2) after 1 year because of loosening of the tibial component. The maximum migration at 1 year was 1.7 mm in Group 1, 1.9 mm in Group 2, 1.3 mm in Group 3, and 1 mm in Group 4. At the 2-year followup, the migrations were 1.8 mm, 1.5 mm, 1.4 mm, and 1 mm in Groups 1, 2, 3, and 4, respectively. The inducible displacement that occurred at 1 year was 0.6 mm in Group 1, 0.5 mm in Group 2, 0.4 mm in Group 3, and 0.4 mm in Group 4. The hydroxyapatite coating had a strong positive effect on the tibial component fixation. No prosthesis in the hydroxyapatite groups showed continuous migration.

Aged↗

PubMed1999

Tourniquet release for hemostasis increases bleeding. A randomized study of 77 knee replacements.

We conducted a prospective, randomized study of 77 primary knee replacement operations on 75 patients (52 women), with a mean age of 71 years, to evaluate the effect of tourniquet release for hemostasis on blood loss and transfusion requirements. The operations were all done with spinal anesthesia and the use of a midline skin incision and medial parapatellar approach. In group I, the tourniquet was released for hemostasis before the wound was closed. In group 2, the tourniquet was first released after the wound was closed and a compressive dressing had been applied. The total intra- and postoperative blood losses were, on average, 858 mL (SD 443) in group I and 589 mL (347) in group 2 (p = 0.01). The median units of blood given and the postoperative decreases in hemoglobin values were similar in both groups. In a subgroup of 45 cementless prostheses, the 25 patients with prostheses allocated to group 1 lost 1022 mL (397) blood, compared to 646 mL (333) by the 20 patients with prostheses in group 2 (p = 0.01). Our findings speak against the efficacy of tourniquet release for hemostasis in knee replacement surgery.

Adult↗

PubMed1999

Patient satisfaction, function and return to work after knee arthroplasty.

We investigated the working status during 2 years before and 2 years after primary knee prosthetic operation for arthrosis in order to identify preoperative factors predicting patient satisfaction, function and working capacity. 162 patients (86 women) younger than 60 years of age when operated on with a knee prosthesis during 1993 were studied. 91% of the patients returned a Nottingham Health Profile (NHP) questionnaire, and the Social Insurance Office could supply data on all patients. There was a positive association between the duration of pre- and postoperative sick-leave in the patients who returned to work. Preoperative sick-leave longer than 180 days increased the risk of postoperative disability pension, which was not found to be influenced by the grade of the work. Among the 52 patients who returned to work postoperatively, all 6 NHP functional categories were better in the patients with less than 180 days of preoperative sick-leave than in the patients with more than 180 days of preoperative sick-leave. The overall patient satisfaction was greater among patients who went back to work postoperatively. We conclude that long sick-leave before a knee prosthetic operation increases the risk of long postoperative sick-leave and disability pension and impairs the quality of life.

Arthritis↗

PubMed1998

Simultaneous measurements of sagittal knee laxity with an external device and radiostereometric analysis.

We obtained simultaneous measurements of sagittal knee laxity in 12 consecutive patients after reconstruction of the anterior cruciate ligament (ACL), using the Stryker laxity tester and radiostereometric analysis (RSA). The mean anteroposterior (AP) displacement when a 90 N load was applied in both directions was 5.3 +/- 2.7 mm with RSA and 9.8 +/- 1.6 mm with the external device (p < 0.001). The corresponding measurements at a load of 180 N were 5.7 +/- 2.4 mm and 13.8 +/- 3.7 mm, respectively (p < 0.001). More than 50% of the sagittal knee movement, as measured by the external device at a load of 180 N, was not true femorotibial displacement of the joint but was due to soft-tissue deformation.

Adolescent↗

PubMed1997

Persistent stability 3 years after reconstruction of the anterior cruciate ligament. A radiostereometric analysis (RSA) of 20 patients.

We measured, by radiostereometric analysis (RSA), the sagittal knee laxity in 20 consecutive patients with chronic anterior cruciate ligament injuries before, 1 year and 3 years after reconstruction with a free bone-patellar tendon-bone graft. The grafts had been perioperatively tensioned, using a 10-15 N load. An increased displacement with increasing load was present before reconstruction, but we found no differences between 100 and 150 N stress load 1 and 3 years after the operation. The total anteroposterior displacement decreased from 12.7 mm before the reconstruction to 5.1 mm 1 year and 5.6 mm 3 years postoperatively, using a stress load of 150 N. Thus, we found both a definite end-point of joint displacement and persistent stability without elongation of the graft with time, when care was taken not to over-constrain the knee by a high initial graft tension.

Adult↗

PubMed1990

[Perioperative hypothermia in adults].

In perioperative hypothermia, a central temperature of less than 36 degrees C develops in connection with anaesthesia and operation. Perioperative hypothermia constitutes a daily problem which results in increased morbidity and mortality in risk groups. The influence of anaesthetic agents on temperature regulation is reviewed. The postoperative hypothermic phase with increased oxygen requirement on rewarming increases the risk of development of complications, including cardiac complications. The risk groups and prophylactic methods for hypothermia are mentioned. Higher temperatures in the anaesthetic room, prewarming of infusion fluids and employment of infusion warmers should be employed with all anaesthetics. In patients in risk groups, extensive employment of combined methods of prevention of hypothermia is recommended.

Adolescent↗

PubMed1990

[The heating effect of two infusion warmers].

An investigation was performed to compare the Animec infusion warmer with the Fenwall infusion warmer. The maximal increase in temperature for the Animec infusion warmer was 8.9 degrees C and this was recorded with a flow of 395 ml/hour. The values for the Fenwall infusion warmer were 12.0 degrees C with a flow of 1,527 ml/hour. An estimate is made of the reduced energy deficit with employment of the two infusion warmers. It is concluded that supply of energy to the infusion warmers. It is concluded that supply of energy to the infusion fluid depends on the flow of fluid through the infusion warmer and the capacity of the infusion warmer. Great differences were observed in the capacities of the two infusion warmers to compensate for the peroperative energy deficit at the rates of flow normally recommended.

Hot Temperature↗