Abstract
Introduction Surgical management of low back pain secondary to multilevel degenerative disc disease and internal disc disruption (DDD/IDD) remains controversial. There is little published evidence as to the success of multilevel total disc replacement (TDR). The purpose of this study is to assess two-level TDR as a treatment option for multilevel DDD/IDD, report the postoperative return to work rate, and assess the results of compensation patients and patients with prior surgery.
Methods This is a retrospective review of 79 patients with multilevel DDD/IDD who received two-level TDR with the Charité artificial disc prosthesis. One patient declined study entry. The average follow-up was 29 months (12–72). In 69 cases L4-5/L5-S1 TDR was pre-formed, in 8 cases L3-4/L4-5, and in 1 case L3-4/L5-S1. Seven patients received a fusion at an adjacent level. The outcome measures used were back and leg Visual Analogue Score (VAS), Oswestry Disability Index (ODI), and Roland-Morris Disability Questionnaire (R-MD). Data were collected preoperatively and postoperatively at 3, 6, 12, and 24 months, and annually thereafter. All patients completed preoperative and end-point outcome measures; although some of the postoperative outcome data was incomplete. Patient compensation status and postoperative return to work was documented.
Results When comparing preoperative and end-point assessments, there was a 77.9% improvement in back VAS, an 85.7% improvement in leg VAS, a 35 point (68.1%) improvement in ODI, and a 12.4 point (71.9%) improvement in R-MD. As some postoperative outcome measures were not completed, subgroups with complete data were analysed. Fifty patients completed a 12-month assessment. There was a 79.7% improvement in back VAS, an 89.7% in leg VAS, a 36.0 point (70.4%) reduction in ODI, and an 11.8% (74.7%) reduction in R-MD. Thirty-four patients completed the 24-month data. There was an 80.6% improvement in back VAS, a 91.6% in leg VAS, a 43.1 point (78.0%) reduction in ODI, and a 13.6 (77.5%) reduction in R-MD.
Nine patients had undergone prior surgery. When compared with those with no prior surgery, no statistical difference was detected. There was a trend for the ODI and back VAS scores of the patients with previous surgery improved more quickly in the early stages. Fourteen patients were involved in compensation claims at the time of surgery. Their results were compared with those patients without compensation claims. The numbers were too small to be statistically significant, but there was a trend suggesting recovery was delayed in the compensation group. However, at 24 months there was no difference in the outcome scores. In the patient sample, 87% of patients returned to work. No major intra-operative complications were documented. One neurological complication was documented. Two revision procedures were preformed. No prosthetic failure occurred.
Discussion TDR in the lumbar spine for treatment of multilevel DDD/IDD is a viable option and will become part of the armamentarium of spine surgeons and possibly the treatment of choice. The postoperative improvements in outcome measures are significant and sustained. Prior surgery and compensation does not preclude a good result.
The abstracts were prepared by Professor Bruce McPhee. Correspondence should be addressed to him at Orthopaedics Division, The University of Queensland, Clinical Sciences Building, Royal Brisbane & Women’s Hospital, Herston, Qld, Australia
