Introduction: today there is still no consense in reconstruction of severe acetabular defects in hip revision. Since 1988 we use size matched impacted acetabulum allografts. We evaluate how they behave in the mid- and longterm.

Material and method: we present our first 44 transplants with a mean follow-up of 11,2 years (range 6 to 17). The mean age of the patients was 58,6 years (range 19 to 83). According to Gross Classification 26 cases presented an acetabular defect type III while 18 presented type IV. Evaluation included Merle D’Aubigne Score and radiological assessment of allograft and cup according to Engh Criteria (JBJS, 1994).

Results: homogenization of the radiological trabecular pattern was observed in 42 from 44 cases (95,4 %). There were 3 infections and 7 cases of aseptic loosening (15,9 %), that were revised with new cup implantation. Up to now none of these 7 cases have shown further signs of loosening. According to the Kaplan-Meier’s curves the overall predictive survival rate was 76.4 % at 15 years. In cases of pelvic discontinuity (type IV) survivorship was significantly higher (85,7%, p=0,018). There was a highly marked improvement in Merle D’Aubigne Score in Gait (2,2 preoperative – 4,9 at follow-up, p=0,021) and Pain (2,5 preoperative 5,4 at follow-up, p=0,032).

Conclusions: despite published reports with high incidence of failures in the midterm with structural allografts this serie shows clearly that a size matched impacted acetabulum allograft can be successfull in severe defficiencies if proper donor selection and excellent fixation technique is undertaken.

Introduction and Objectives: This is a retrospective study on the treatment of lumbar degenerative disk disease (LDDD) using intervertebral arthroplasty. The lack of uniformity in the treatment of LDDD, persistence of pain even with solid fusion, and the possibility of changes over the fusion site have encouraged us to seek other solutions for this condition. Total intervertebral arthroplasty has been proposed as a possible alternative for selected cases of LDDD.

Materials and Methods: Between November 1999 and July 2002, 16 patients with LDDD were treated surgically using third-generation total intervertebral arthroplasty (Link SB Charité III) with a chromium-cobalt alloy and ultra-high molecular weight (UHMW) poly-ethylene. Average follow-up time was 14 months (6-36 months), and average age was 42 years (35–52). There were 11 females and 5 males. All patients underwent radi-olographic studies, CT scan, MRI, and discography (minimum 2 levels). Indications included LDDD of one to three segments, absence of root tension signs, absence of complete disc collapse, and iconography including concordant discography. LDDD was primary in 11 cases and post-discectomy in 5 cases. Surgery was indicated when at least 6 months of conservative treatment failed to yield results. Blood loss and length of hospital stay were compared to a similar group that underwent posterolateral arthrodesis. Pain, function, and degree of disability were evaluated before and after surgery using GEER (1999) instruments for the evaluation of degenerative lumbar pathology. Increase in height of the posterior intervertebral space and segmentary lordosis were also measured.

Results: Preoperative VAS: 7.8; postoperative VAS: 2.3. Disability index (Oswestry) was 41.3% preoperative and 10.8% postoperative. Average increase in height of posterior intervertebral space was 2.4mm, and mean segmental lordosis was 19.5°, which remained constant through the end of the follow-up period. Average hospital stay was 4.8 days (3–15) compared with 7.5 (5–18) for a group of patients who underwent suspended arthrodesis of L4–L5 with a much smaller quantity of blood loss. No infections were found. Complications: One patient developed an epidural haematoma, which was treated conservatively. Another developed a postoperative retroperitoneal haematoma, which was also treated conservatively. In neither case was there an adverse effect on the outcome of the procedure. One patient showed malpositioning of the prosthetic components on follow-up radiographs, with poor clinical progression at one year postoperative. The patient was treated with posterolateral fusion and right L5 foraminotomy. No infections were seen.

Discussion and Conclusions: Treatment of LDDD with intervertrebral arthroplasty was shown to be effective in the short term, if strict guidelines are followed. Aggressive surgical management is highly inferior to conventional arthrodesis. A longer follow-up period is needed to confirm the validity of this treatment. Technical error in malpositioning of the components in one case caused a poor result.