[Indication, biomechanics and early results of artificial disk replacement]. / Indikation, Biomechanik und Frühergebnisse des künstlichen Bandscheibenersatzes.

AIM: Judgment of factors concerning the indication for the implantation of an artificial disc endoprosthesis, the rating of this operation and biomechanical considerations. METHOD: Presentation of the indication and the value of a new operative concept in comparison to a so-called dynamic stabilization procedure (Dynesys' method). Indications for the operation are: unsuccessful, orthopedic conservative treatment for > 6 months, segmental pain, age < 45 years, evidence of an MRI demonstrable mono- or bisegmental disc degeneration with or without disc prolabation, exclusion of psychogenic disease and positive preoperative, diagnostic measures such as facet joint infiltration and discography. RESULTS: In an earlier investigation the efficacy of the Link method was demonstrated as shown by the reduction of the analgesic use, the angle of the lumbar lordosis (L1-S1) increased from 35.6 degrees to 42.6 degrees (20.2 %), the segmental angle from 19 degrees to 30 degrees (57.5 %). The new investigation using the Aesculap endoprosthesis resulted in a change of the angle of lumbar lordosis from 35.4 degrees to 45.4 degrees (25.4 %) and a change of the segmental angle from 17.3 degrees to 29.1 degrees (57.6 %). This method is a real endoprosthetic instrumentation in the field of spinal surgery. CONCLUSION: In younger patients with mono- or bisegmental disc degeneration there is an indication for the implantation of a disc endoprosthesis. A facet joint arthrosis and an age over 45 years are contraindications for the operation. The indication in patients with a classic failed back surgery syndrome is still unclear, the improvement of the instrumentation and a further adaptation of the systems to the known biomechanics of the lumbar spine are mandatory as is an intensive discussion of the operative procedure in the case of revision operations. The Dynesys method, with the inherent danger of segmental kyphozitation, a published, significant revision quota combined with a reduction of motility, does not fulfill this criterion.

[Disc replacement with the SB Charité endoposthesis - experience, preliminary results and comments after 35 prospectively performed operations]. / Der Bandscheibenersatz mit der SB Charité-Bandscheibenendoprothese - Erfahrungen, Frühergebnisse und Feststellungen nach 35 prospektiv durchgeführten Operationen.

UNLABELLED: Aim of this prospective study was an investigation concerning the indication for the implantation of an artificial disc endoprosthesis and the rating of this operation. METHOD: 35 patients with 11 bi- and 24 monosegmental implanted disc endoprosthesis were observed over an average follow-up of 14.7 months. Indications for the operation were: unsuccessful, orthopedic conservative treatment > 6 months, segmental pain, age < 45 years, evidence of a radiologic (MRI) demonstrable mono- or bisegmental disc degeneration with or without disc prolabation, exclusion of psychogenic disease and positive preoperative, diagnostic measures. RESULTS: The average stay in the hospital was 16.8 days (preoperative: 4.3 days), the average operation time 85.5 minutes, the average blood loss was 125 ccm. 23 patients were operated in L 5 / S 1, 20 in L 4 / 5 and 2 in L 3 / 4. NSAR was given in 33 patients preoperatively, opiates in 2 further patients, postoperatively NSAR was necessary in 5 patients, opiates in 2 patients. The preoperative angle of lordosis (L 1 - S 1, n = 25) was changed from 35.6 degrees to 42.6 degrees (20,2 %), the segmental angle from 19 degrees to 30 degrees (57.5 %). CONCLUSION: The implantation of the artificial disc was followed by a good pain relief in patients suffering from a mono- or bisegmental disc degeneration. In patients with a facett joint arthrosis and elderly patients > 45 years this method cannot be used, the indication in patients with failed back surgery syndrome cannot be estimated yet. Improvements of the instrumentation and the discussion in the case of revisional operations are mandatory.