Comparison of radiofrequency treatment and mechanical debridement of fibrillated cartilage in an equine model.

OBJECTIVE: To compare a radiofrequency energy (RFE) prototype probe to mechanical debridement (MD) and a commercially available RFE system used for chondroplasty in the treatment of an experimentally created partial thickness cartilage lesion in horses. The study design was experimental, randomized complete block, n=8, using fifteen mature ponies. METHODS: Grade 2 to 3 cartilage lesions were prepared in both patellae. After 10 months duration, the injuries were used to study the effects of MD, a commercially available bipolar RFE device (CoVac 50; ArthroCare Corporation) and a prototype monopolar RFE device (Smith & Nephew Endoscopy). Six months after treatment the patellae were examined for chondrocyte viability and cartilage structure. RESULTS: Mean depth of cell death was significantly different among groups (controls, MD

Treatment of head and neck cancer with bone or cartilage invasion by surgery and postoperative radiotherapy.

PURPOSE: The study goal was to review our experience with patients with bone or cartilage invasion (BCI) by adjacent head and neck cancer (HNC) who were treated with curative surgery and postoperative radiotherapy (SPR). PATIENTS AND METHODS: Thirty-eight individuals treated with SPR for HNC with BCI were identified after review of the radiation oncology charts and pathology reports for the period 1981 through 2000. RESULTS: The thyroid cartilage and mandible were predominantly invaded by HNC. The follow-up time for the surviving patients was 65.5 months (range, 17 to 106 months). The local, regional, and distant relapse rates were 5%, 11%, and 13%, respectively. The overall disease-free survival rates at 3 and 5 years were 54% and 41%, respectively. CONCLUSION: Although these results were not obtained from a randomized trial, the present observations may be beneficial in clinical decision making concerning patients with HNC and contiguous invasion of bone or cartilage.

Assessment of low-power laser biostimulation on chondral lesions: an "in vivo" experimental study.

The purpose of this study was to evaluate whether intraoperative laser biostimulation can enhance healing of cartilaginous lesions of the knee. Surgery was performed on eighteen rabbits: a bilateral chondral lesion of 1.25 +/- 0.2 mm in length and 0.8 +/- 0.2 mm in width was created in the femoral medial condyle with a scalpel. The lesion in the left knee of each animal was treated intraoperatively using the diode Ga-Al-As 780nm. laser (300 Joules/cm2, 1 Watt, 300 Hertz, 10 minutes), while the right knee was left untreated, as control group. The animals were divided into three groups, A, B and C, according to the survival time after surgery, two, six and twelve weeks, respectively. The explants from the femoral condyles, both treated employing laser energy and left untreated, were examined histologically. Results showed a progressive filling with fibrous tissue of the cartilaginous lesion treated with laser irradiation, while no changes in the original lesion of the untreated group were observed at the end of the study. Maybe, in this experimental research, underexposure to laser irradiation was the cause for the absence of the necessary conditions for biostimulation.

[Holmium laser in chondrology: potentials and prospects]. / Vozmozhnosti i perspektivy primeneniia gol'mievogo lazera v khondrologii.

To study the mechanism of simulation of a cartilage, to define the optimum parameters and laser radiation regimens, the authors made a complex of in vitro experiments on the cartilages of the nasal septum in man and domestic animals and in vivo experiments on those of the concha in rabbits and pigs. Holmium laser radiation is shown to be the most suitable tool for formation of a cartilage. Evidence is provided for the possibility of irreversibly altering the shape of a cartilage during laser radiation. A procedure has been developed for non-invasive correction of the septum of the nose for its curvature. Restored or improved nasal respiration was observed in more than two thirds of the patients. Laser surgery is not of age-limited application, it is noninvasive, can be performed in the outpatient settings and requires no drug treatment in the postoperative treatment.

Fast neutron radiotherapy for sarcomas of soft tissue, bone, and cartilage.

The basic radiobiological rationale for the use of fast neutron radiotherapy in the treatment of classically radioresistant tumors such as soft tissue sarcomas, osteogenic sarcomas, and chondrosarcomas is reviewed. There are no definitive randomized studies comparing high and low linear energy transfer radiotherapy for these tumor systems, but a review of published series is highly suggestive of a therapeutic advantage for fast neutrons. For soft tissue sarcomas, the local control rate is 53% (158 of 297) with fast neutrons, compared with 38% (49 of 128) with photons/electrons; for osteogenic sarcomas, the local control rate is 55% (40 of 73) with fast neutrons, compared with 21% (15 of 73) with photons/electrons; and for chondrosarcomas, the local control rate is 49% (25 of 51) with fast neutrons, compared with 33% (10 of 30) with photons/electrons. An ongoing clinical trial for these tumors is also described.