No abstract

The purpose of this study was to analyze the impact of monopolar radiofrequency energy treatment on subchondral bone viability. The femoral grooves of six chinchilla bastard rabbits were exposed bilaterally to monopolar radiofrequency energy for 2, 4 and 8 s, creating a total of 36 defects. An intravital fluorescence bone-labeling technique characterized the process of subchondral bone mineralization within the 3 months following exposure to radiofrequency energy and was analyzed by widefield epifluorescence optical sectioning microscopy using an ApoTome. After 2 s of radiofrequency energy exposure, regular fluorescence staining of the subchondral bone was evident in all samples when compared to untreated areas. The depth of osteonecrosis after 4 and 8 s of radiofrequency energy treatment averaged 126 and 942 µm at 22 days (P < .05; P < .01). The 4 s treatment group showed no osteonecrosis after 44 days whereas the depth of osteonecrosis extended from 519 µm at 44 days (P < .01), to 281 µm at 66 days (P < .01) and to 133 µm at 88 days (P < .05) after 8 s of radiofrequency energy application. Though radiofrequency energy may induce transient osteonecrosis in the superficial zone of the subchondral bone, the results of this study suggest that post-arthroscopic osteonecrosis appears to be of only modest risk given the current clinical application in humans.

Although patients subjective rating of knee function and knee pain was nearly identical in both groups objective knee scores disclosed impaired knee function in our patients treated for Cyclops syndrome.

No abstract

Between 01/2006 and 04/2007, the dorsal medial femoral condyle was used as a donor site in 16 patients. All patients were evaluated preoperatively and after 1 year using the American Knee Society Score (KSS), the Western Ontario and McMaster Universities (WOMAC) Score, the Tegner Score, and the visual analog scale (VAS) pain. The mean follow- up was 13.9 (+/-4.3) months. The mean defect area was 4.6 (+/-2.2) cm(2). The mean KSS, Tegner Score, and WOMAC Score improved from 123.1 (+/-41.5), 2.8 (+/-0.9), and 73.3 (+/-50.2) points preoperatively to 171.3 (+/-16.9), 3.4 (+/-0.6), and 26.1 (+/-17.6) points after 13.9 months (p < 0.05). The VAS pain improved from 5.3 (+/-2.7) to 2.4 (+/-1.8) points (p < 0.05). One patient with an osteochondral defect of 8 cm(2) at the medial femoral condyle (Ahlbäck's disease) still complains of pain during deep squatting. The dorsal medial femoral condyle can be recommended as donor site for OCT. The minimally invasive approach has proven to be safe and simple with a low complication rate.