Study design: Analysis of segmental and total lumbar range of motion (ROM) before and after total lumbar disc replacement.
Objective: To examine the relationship between absolute segmental and total lumbar ROM and evolution of ROM on clinical outcome.
Summary of background data: At the moment, data are scarce with regard to the evolution of total lumbar ROM (t-ROM) and segmental ROM (s-ROM) after total lumbar disc replacement. Moreover, the influence of ROM on clinical outcome still is unclear and remains a matter of controversial debate. METHODS.: Forty patients operated on for mono- or bisegmental symptomatic degenerative disc disease with a total of 45 artificial discs (ProDisc-L, Synthes) were analyzed. Pre- and postoperative s-ROM and t-ROM were measured on flexion/extension radiographs. The Oswestry Low Back Pain Disability Questionnaire and the Short Form 36 Health Survey were obtained pre- and postoperatively with a minimum follow-up of 3 years (37-64 months).
Results: Neither the s-ROM (pre-/postoperatively: 6.9 degrees/7.3 degrees) nor the t-ROM (pre-/postoperatively: 34.9 degrees/35.8 degrees) did change significantly after implantation of an artificial disc. Postoperatively, there was an increase of s-ROM (t-ROM) in 40% (40%), a decrease in 35% (30%), and no change in 25% (30%) of the patients. A significant inferior clinical outcome only was observed in patients with decreased t-ROM. The resulting postoperatively s-ROM had no significant impact on outcome.
Conclusion: Neither the absolute s-ROM nor the evolution of s-ROM (increase, decrease, unchanged) was positively correlated with better clinical outcome. Although a positive correlation was observed with regard to t-ROM.