Background

Improving quality and efficiency is a priority in health policy. Several studies have shown a correlation between high hospital volume and improved results of surgery. In Norway, orthopaedic surgeons operate a relatively low number of total knee replacements compared with other countries. The number of total knee replacements has, however, increased significantly over the past 10 years.

Some studies have also shown an association between surgeon volume and outcomes after total knee arthroplasty (TKA).

Introduction: Highly cross-linked polyethylene acetabular cups and Oxinium femoral heads were developed to reduce wear debris induced osteolysis. Laboratory tests have shown less wear with these new materials. This RSA-study was performed to compare these new materials in vivo with conventional bearing materials used in total hip arthroplasty.

Methods:150 patients were randomized to 5 groups. The patients received either a cemented Charnley mono-block stainless steel femoral stem with a 22.2 mm head or a cemented Spectron EF femoral stem with a 28 mm head. The Charnley stem articulated with a cemented Charnley Ogee acetabular cup. The Spectron EF stem was used with either cemented Reflection All-Poly EtO-sterilized ultra-high molecular weight polyethylene (UHMWPE) acetabular cups or cemented Reflection highly cross-linked polyethylene (XLPE) acetabular cups, combined with either Cobalt Chrome or Oxinium 28 mm femoral heads. Patients were followed up with repeated radiostereometric analysis (RSA) for two years to assess the rate of penetration of the femoral head into the cup (MTPM).

Results: At 2 years follow-up the mean MTPM (95 % CI) for Charnley Ogee (n=25) was 0.20 mm (0.11–0.29). For the Spectron EF femoral stem used with Reflection All-Poly UHMWPE acetabular cups the mean MTPM (CI) at 2 years was 0.40 mm (0.23–0.57) when combined with Cobalt Chrome femoral head (n=23) and 0.50 mm (0.29–0.71) when combined with Oxinium femoral head (n=16). When using the Spectron EF femoral stem with Reflection XLPE combined with Cobalt Chrome (n=27) or Oxinium (n=24) femoral head the mean MTPM (CI) at 2 years was 0.19 mm (0.10–0.28) and 0.18 mm (0.07–0.29), respectively. There were no differences in penetration between the Charnley/Ogee, XLPE/CoCr and XLPE/Oxinium groups (student t-test, p=0.5–0.8). There was no statistically significant difference between the two Reflection All-Poly UHMWPE groups (p=0.09). The groups with Reflection All-Poly cups had a statistically significant higher penetration than the three groups mentioned above (p< 0.001).

Discussion: The use of Reflection XLPE cups instead of Reflection All-Poly cups reduced femoral head penetration at 2 years. We used the Charnley Ogee cup as a reference due to a long clinical record. This cup was superior to Reflection All-Poly, but not Reflection XLPE, regarding femoral head penetration. Because the femoral head of Charnley Ogee is smaller than the Oxinium/Cobalt Chrome head it might be more clinical relevant to measure volumetric wear. The groups with Oxinium heads did not have less wear than the groups with Cobalt Chrome heads after 2 years follow-up. Further follow-up is needed to evaluate the benefits, if any, of Oxinium femoral heads in the clinical setting.

Objective: To assess the effectiveness of total disc replacement (TDR) (Charité SB III) for treatment of lumbar discopathy and to report the preliminary clinical results after a minimum follow-up period of two years

Materials and Methods: From 49 patients who underwent lumbar TDR, 31 patients fulfilled the criteria for clinical evaluation at least 2 years after surgery. The mean age was 39ys (range 29 – 48). Preoperative diagnosis included degenerative disc disease in 27 patients and 4 patients had post discectomy back pain. 44 disc prosthesis were implanted, 18 patients had a single level disc replacement and 13 patients had two level replacement. All patients were studied prospectively and clinical results evaluated by assessing preoperative and postoperative Oswestry Disability Index questionnaire and Visual Analogue Scale for back pain. Pre and postoperative patients’ work status as well as patient satisfaction were also assessed. The mean postoperative follow up was 3.3years (range 2 – 8 years). Statistical analysis of the results was done with the Wilcoxon Signed Ranks Test.

Results: There were significant improvements of the clinical outcome measures. Mean post operative ODI compared to mean preoperative scores of 19 and 53 respectively (p< 0.0001) and mean postoperative VAS compared to mean preoperative scores of 2.5 and 7.5 respectively (p< 0.0001). Success rates showed 51.6% of patients had an excellent result (relative improvement of ODI score, > 75%), 19.4% had a good result (relative improvement of ODI score, 60% to74%), and 29% had a fair and poor results (relative improvement of ODI score, < 60%). No major or approach related complications were encountered.

Conclusions: TDR is an effective method of treating discopathic low back pain. The medium term results are comparable to those obtained following traditional lumbar arthrodesis. Yet longer term results are still needed to comment on adjacent segment load transfer and progression of degenerative changes.

Objectives: Is to present the short term outcome of lumbar Artificial Disc Replacement in the Royal Devon and Exeter Hospital, UK.

Design: Review of literature and the short term outcome.

Summary of background data: The mainstay of surgical treatment for discogenic low back pain has been spinal fusion for many decades. The outcome of fusion procedures has been somewhat unpredictable and is linked with some limitation in the activities related to spinal motion.

Recently and in the last few years a relatively new procedure was introduced to spinal surgery practice which is the artificial disc replacement, the potential benefit of which is to relief back pain as well as keeping the spinal motion.

In this study, we are reporting our early experience in the results and short term outcome of lumbar artificial disc replacement done on 26 patients in The Royal Devon and Exeter Hospital

Methods: The 26 cases were operated upon in the duration between 1996 and 2003. We used artificial disc replacement.

Results: Our results based on ODSS and the VAS were good to excellent with patient satisfaction of about 87%

Conclusion: The Artificial disc replacement procedure in the lumbar and lumbosacral region is promising in short term outcome , however the long term results should be carefully evaluated.