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Biomedical subjects

W E Siebert

Publications and source records attributed to W E Siebert.

21 records · Page 2Linked to original sources

[The significance of the activity score in evaluating knee ligament reconstructions].

In a follow-up study of 156 patients after knee ligament reconstruction for chronic instability, the results of subjective Lysholm score grading and of Tegner activity grading were compared. The postoperative Lysholm score averaged 85 +/- 13.2 points, the activity scores 6.9 +/- 0.9 points prior to instability, 1.7 +/- 0.9 points preoperatively and 5.9 +/- 1.2 points postoperatively. 89 patients reached their preinjury activity level, the average improvement through surgery was 4.2 +/- 1.6 points. Non-active patients regularly returned to their original activity-level, competitive athletes were less likely to regain their previous activity. The subjective results of athletes and non-athletes showed no significant differences. The postoperative activity level clearly correlated to subjective grading by the patient. For scoring results after knee ligament surgery, we use the subjective Lysholm score and an activity score based on average German sports activities.

Activities of Daily Living↗

[Use of lasers in orthopedic surgery--a mutagenesis risk?].

Since ten years different laser systems have been used in arthroscopic procedures and percutaneous laser disc decompression. A potential mutagenic risk has not been excluded yet. From photobiology it is known that light in the UV-range is the main source of mutations. Therefore the aim of our study was to determine the mutagenic risk of laser systems at UV-wavelengths. The BALB/3T3 cell line was irradiated at the Excimer wavelengths 248 nm and 308 nm. Transformation rates were compared with non-irradiated cells and the effect of 1 Gy-Roentgen irradiation. Pulse energy, frequency and irradiation time were varied over a broad range. The effect of double irradiation was also examined. For 308 nm no significant transformation rate was found (p < 0.18). In contrast 248 nm showed a highly significant transformation rate (p < 10(-9). Transformation rate after Roentgen irradiation exceeded that of the negative control about two orders. While a certain mutagenic risk exists for 248 nm application of the wavelength 308 nm seems harmless. Our data therefore represent an essential contribution to long term laser safety both for the physician and his patient.

3T3 Cells↗