Biomedical subjects

Hakon Kofoed

Publications and source records attributed to Hakon Kofoed.

3 recordsLinked to original sources

PubMed2004

Scandinavian Total Ankle Replacement (STAR).

Fifty-eight patients with either rheumatoid arthritis or osteoarthritis were treated with meniscal-bearing ankle prostheses. The concept was to mobilize, align, and stabilize the ankle before resurfacing it. Cement was used for prostheses fixation in 33 patients (1986-1989) and 25 patients had fixation without cement (1990-1995). All patients in one prospective series were followed up yearly with radiographs and with a clinical scoring system giving a maximum of 100 points. This allowed for a patient-controlled prospective study. No patients were lost to followup. The only detectable difference in the treatment was the fixation mode. For the purpose of comparing patients with cemented and uncemented prostheses, the patients who had surgery between 1986 and 1989 were not followed up after 1997, and patients who had surgery between 1990 and 1995 were not followed up after 2002. The mean followup was 9.4 years. Failure was defined as prosthesis revision or change to arthrodesis for any reason. In the cemented group, nine of 33 patients had revision surgery or fusion. In the uncemented group, one of 25 patients had revision surgery. Survivorship analysis for 12 years based on life tables showed a 70% survival rate (confidence limit, 60.3-78.5) for the cemented group and 95.4% survival rate (confidence limit, 91.0-99.9) for the uncemented group. The average clinical scores at the latest followup were 74.2 +/- 19.3 for the cemented group and 91.9 +/- 7.4 points for the uncemented group. Therefore, unconstrained meniscal-bearing ankle prostheses should be uncemented.

Adult↗

PubMed2004

Bone mineral density, gait analysis, and patient satisfaction, before and after ankle arthroplasty.

Bone mineral density (BMD) and patient satisfaction were measured and gait analysis was performed in patients treated with unilateral dual-coated ankle arthroplasty. The study comprised 14 patients (eight women and six men) measured preoperatively and at a median of 15 (range, 12-26) months after surgery. BMD was measured bilaterally in the distal tibia and in the calcaneus. A plantar pressure analysis was performed, including foot contact duration and a new index for describing the ground reaction force curve called the Valley Index (VI). The patients also evaluated their level of pain, ability to cope with daily activities, adaptation of shoes, and walking ability before surgery and at follow-up on a visual analogue scale (VAS). Bone mass significantly increased adjacent to the tibial part of the prosthesis. The patients experienced less pain and improved walking and performance in daily activities. There was also a decrease in foot contact duration as well as an increase in VI and ankle range of motion. Change in bone mass was the variable that correlated best with the patients' evaluation of the general outcome of ankle arthroplasty. Correlations among other variables are described. The study concluded that a fairly simple analysis of the ground reaction force curve, bone mass measurements, and VAS can demonstrate that ankle arthroplasty is able to normalize gait, decrease foot contact duration, increase bone mass, and reduce pain.

Adult↗

PubMed2002

Radiolucency adjacent to the tibial component in total knee arthroplasty.

This study determined the accuracy of standard radiographs in observing radiolucency adjacent to the tibial component in total knee arthroplasty. A model of the proximal tibia was used. Plastic sleeves of different heights were glued under the tibial tray to imitate radiolucency. By tilting the x-ray tube 1degrees at a time, an investigation was performed to determine how many degrees it would take to cover the heights of the different plastic sleeves. In a clinical study of patients at standard follow-up, 21 knees were examined using standard radiographs. Radiographs using image intensification were then taken of the same knees to obtain radiographs with views parallel to the plane of the tibial tray. The results of the study on the phantom showed that a 1degrees deviation of the x-ray beam from the optimal position would obscure a 0.5-mm "radiolucency." This was true for radiolucencies of 2, 3, 4, and 5 mm. This was confirmed in the clinical study where < or = 4 mm of radiolucency was obscured on standard radiographs. Therefore, standard radiographs cannot be used to determine radiolucency. The 2-mm radiolucency normally associated with loosening is not clinically valid.

Aged↗