RESUMO
BACKGROUND: Single and multilevel lumbar arthroplasty has had excellent results, but the L5-S1 level frequently has pathology that precludes arthroplasty. This study evaluated clinical outcomes and sagittal range of motion (ROM) of operated levels and adjacent motion segments in single- and multiple-level ProDisc-L above a simultaneous L5-S1 fusion (hybrid) after a 2- to 6-year follow-up. METHODS: In this prospective cohort study, 46 patients underwent simultaneous lumbar total disc replacement (TDR) at one to three levels and anterior lumbar interbody fusion (ALIF) at L5-S1. Twenty-three patients had L5-S1 ALIF + L4-5 TDR, 19 patients had L5-S1 ALIF + two-level TDR, and 4 patients had L5-S1 ALIF + three-level TDR. Oswestry disability index (ODI) and visual analog scores (VAS) of patient satisfaction (VAS-S) and pain (VAS-P) were recorded. Sagittal motion on pre- and postoperative lumbar radiographs at each operative segment and adjacent segment was acquired. Patients were evaluated preoperatively and at 6 weeks, 3 months, 6 months, and annually for 24 to 72 months postoperatively. RESULTS: For clinical results, there were no differences among the groups for age, gender, body mass index, tobacco use, or worker's compensation status. At 2-6 years postoperation, all patients had significant reductions in ODI and VAS scores. For radiographic results, at the nonsurgical level adjacent to the TDR + ALIF constructs, the mean preoperative ROM was 9.40 ± 1.80° compared with 10.50 ± 2.25° postoperatively. The mean preoperative ROM at levels undergoing TDR was 10.4 ± 2.71° versus 12.6 ± 2.25° postoperatively. There was no statistically significant difference in ROM at each prosthetic motion segment between patients receiving one-, two-, or three-level TDR. The mean preoperative ROM at the L5-S1 segment to undergo fusion was 2.4 ± 2.44°, with all patients having a postoperative ROM of 0.00°. CONCLUSIONS: Multilevel TDR above an L5-S1 ALIF (hybrid procedure) preserves ROM at the individual TDR levels and does not reduce the fusion rate of the L5-S1 fused level. Most significantly, the nonoperative adjacent level maintains its preoperative ROM at 2-6 years postoperatively.
RESUMO
BACKGROUND: Recent studies demonstrate the efficacy of lumbar arthroplasty using the ProDisc-L. Patients frequently present with multilevel pathology and may be candidates for multilevel disk replacement. PURPOSE: To evaluate clinical outcomes and sagittal range of motion of operated levels and adjacent lumbar motion segments in multiple-level ProDisc-L constructs after 2-6 years follow-up. PATIENT SAMPLE: A total of 159 patients underwent adjacent 2-level (n=114), 3-level (n=41), or 4-level (n=4) lumbar total disk replacement (TDR). STUDY-DESIGN: This is a prospective cohort. OUTCOME MEASURES: Clinical measures: Oswestry Disability Index and Visual Analog Score of patient satisfaction (VAS-S) and pain (VAS-P) data were collected. Radiographic measures: sagittal motion on preoperative and postoperative lumbar radiographs at each operative segment and adjacent segment. METHODS: Patients were evaluated with radiographic and clinical outcomes measures preoperatively, at 6 weeks, 3 months, 6 months, and annually for 24-72 months postoperatively. RESULTS: Radiographic: at the motion segment adjacent to the TDR, mean preoperative range of motion (ROM) was 8.20±2.88 degrees, compared with 8.40±2.4 degrees postoperatively at last follow-up (P>0.05). Between the 3 TDR groups, there were no significant differences in ROM at any time point except at L5-S1. Across both groups for TDR motion segments, the mean preoperative ROM was 10.15±2.71 versus 12.30±2.25 degrees postoperatively (P=0.011) at last follow-up. At L5-S1 mean preoperative motion was 7.60±3.90 versus 5.81±3.1 degrees postoperatively (P=0.60). Clinical: at 24-72 months postoperatively, all patients had significant reductions in Oswestry Disability Index, VAS-P, and VAS-S scores (P<0.05). At up to 72 months of follow-up, no patient underwent adjacent-level surgery but there were 3 cases of index-level revision surgery. CONCLUSIONS: Multilevel TDR preserves ROM at the individual TDR levels. Most significantly, the nonoperative adjacent level maintains its preoperative ROM at 2-6 years postoperatively. At up to 6 years of follow-up, there has been no need for revision or adjacent-segment surgery. Patients also demonstrate significant improvement in pain and disability at latest follow-up.