Long-Term Results of Anterior-Only Lumbar Interbody Fusions in Rheumatoid Arthritis Patients: Comparative Retrospective Cohort Study.

OBJECTIVE: Rheumatoid arthritis (RA) is a risk factor of lumbar spine surgical failure. The interest of anterior lumbar fusion in this context remains unknown. This retrospective study aimed to compare the outcome of anterior-only fusions between RA patients and non-RA (NRA) patients to treat lumbar spine degenerative disorders. METHODS: NRA and RA groups including anterior-only fusion were compared. Clinical data (Visual Analog Scale score axial back pain scale, the Oswestry Disability Index, and a questionnaire of satisfaction regarding the surgical result); radiologic data (bone fusion, sagittal balance analysis); and adverse events were assessed using repeated measure 1-way analysis of variance. RESULTS: The mean follow-up was 9.5 years (95% confidence interval [7.1-12.2]) for the RA group (n = 13) and 9.4 years (95% confidence interval [8.7-10.3]) for the NRA group (n = 36). Anterior fusion improved clinical outcome without any effect of RA (Visual Analog Scale score axial back pain scale; P < 0.001/Oswestry Disability Index; P = 0.01). The presence of RA influenced neither the satisfaction as the regards the surgical result nor spine balance nor bone fusion. Context of RA increased the surgical revision rate (10 patients [76.9%] for RA group vs. 3 patients [8.8%] for the NRA group; P = 0.001) because of the occurrence of an adjacent segment disease needing surgical revision (P = 0.028), especially the occurrence of intervertebral frontal dislocation (P = 0.02). CONCLUSIONS: As noticed for posterior-only fusion, the anterior lumbar approach in RA patients does not seem to avoid the occurrence of an adjacent segment disease.

Risk factors of instrumentation failure and pseudarthrosis after stand-alone L5-S1 anterior lumbar interbody fusion: a retrospective cohort study.

OBJECTIVE: L5-S1 stand-alone anterior lumbar interbody fusion (ALIF) is a reliable technique to treat symptomatic degenerative disc disease but remains controversial for treatment of isthmic spondylolisthesis. In the present study the authors aimed to identify risk factors of instrumentation failure and pseudarthrosis after stand-alone L5-S1 ALIF and to evaluate whether instrumentation failure influenced the rate of fusion. METHODS: The study included 64 patients (22 [34.4%] male and 42 [65.6%] female, mean age 46.4 years [range 21-65 years]) undergoing stand-alone L5-S1 ALIF using radiolucent anterior cages with Vertebridge plating fixation in each vertebral endplate. Clinical and radiographic data were reviewed, including age, sex, pelvic parameters, segmental sagittal angle (SSA), C7/sacro-femoral distance (SFD) ratio, C7 sagittal tilt, lumbar lordosis (LL), segmental LL, percentage of L5 slippage, L5-S1 disc angle, and posterior disc height ratio. Univariate and multivariate analyses were used to identify risk factors of instrumentation failure and pseudarthrosis. RESULTS: At a mean follow-up of 15.9 months (range 6.6-27.4 months), fusion had occurred in 57 patients (89.1%). Instrumentation failure was found in 12 patients (18.8%) and pseudarthrosis in 7 patients (10.9%). The following parameters influenced the occurrence of instrumentation failure: presence of isthmic spondylolisthesis (p < 0.001), spondylolisthesis grade (p < 0.001), use of an iliac crest bone autograft (p = 0.04), cage height (p = 0.03), pelvic incidence (PI) (p < 0.001), sacral slope (SS) (p < 0.001), SSA (p = 0.003), and LL (p < 0.001). Instrumentation failure was statistically linked to the occurrence of L5-S1 pseudarthrosis (p < 0.001). On multivariate analysis, no risk factors were found. CONCLUSIONS: L5-S1 isthmic spondylolisthesis and high PI seem to be risk factors for instrumentation failure in case of stand-alone L5-S1 ALIF, findings that support the necessity of adding percutaneous posterior pedicle screw instrumentation in these cases.

Stem cell therapy in bilateral osteonecrosis: computer-assisted surgery versus conventional fluoroscopic technique on the contralateral side.

PURPOSE: Surgical management of osteonecrosis with core decompression with stem cell therapy is a new procedure. The technique is performed with fluoroscopic guidance. This study attempts to determine if computer-navigated technique can improve the procedure. METHODS: Thirty consecutive patients with bilateral symptomatic osteonecrosis without collapse were included in this study during the year 2011. A prospective, randomized, and controlled study was conducted on 60 hips (bilateral osteonecrosis) using conventional fluoroscopy technique on one side and computer-based navigation on the contralateral side. Bone marrow aspirated from the two iliac crests was mixed before concentration. Each side received the same volume of concentrated bone marrow and the same number of cells 110,000 ± 27,000 cells (counted as CFU-F). RESULTS: Computer navigation achieved better parallelism to the ideal position of the trocar, with better trocar placement as regards to tip-to-subchondral distance and ideal centre position within the osteonecrosis for injection of stem cells. Using computer navigation took fewer attempts to position the trocar, used less fluoroscopy time, and decreased the radiation exposure as compared with surgery performed with conventional fluoroscopy. At the most recent follow-up (6 years), increasing the precision with computer navigation resulted in less collapse (7 versus 1) and better volume of repair (13.4 versus 8.2 cm3) for hips treated with the computer-assisted technique. CONCLUSIONS: The findings of this study suggest that computer navigation may be safely used in a basic procedure for injection of stem cells.

Influence of the Initial Sagittal Lumbar Alignment on Clinical and Radiological Outcomes of Single-Level Lumbar Total Disc Replacements at a Minimum 2-Year Follow-up.

STUDY DESIGN: Retrospective cohort study OBJECTIVE.: To analyze the clinical and radiographic outcomes of patients undergoing a one-level lumbar total disc replacement (TDR), according to the initial sagittal alignment of the spine. SUMMARY OF BACKGROUND DATA: No authors have highlighted correlation between the initial spinopelvic parameters and the postoperative outcome after a one-level TDR. METHODS: Seventy-eight patients were included: 14 TDR at L4-L5 and 64 TDR at L5-S1 level. Clinical assessment was performed on leg pain and axial back pain Visual Analog Scale (VAS), Oswestry Disability Index, and Short Form-36 Health Survey. Radiographic assessment included full spine standing anteroposterior and lateral films. Data were compared according to the initial lumbar sagittal alignment described by Roussouly. RESULTS: Forty-five female patients and 33 male patients with a mean age of 41.7 years (95% confidence interval [40.3-43.1]) were included. The mean follow-up was 46.4 months (95% [40.6-51.6]). Two patients were considered as Roussouly type 1 (2.6%), 36 patients as type 2 (46.2%), 33 patients as type 3 (42.3%), and 7 patients as type 4 (9%). Preoperatively, there were no clinical differences depending on Roussouly's type of back. Pelvic incidence (P < 0.001), sacral slope (P < 0.001), lumbar lordosis (P < 0.001), and spinosacral angle (P < 0.001) were different between the Roussouly's types of back. Postoperative clinical outcome improved (P < 0.001) but did not vary according to the Roussouly types except for leg pain VAS (P = 0.03). Post hoc tests did not reveal difference between the Roussouly's types and leg pain VAS. Postoperative radiographic outcomes did not change excepted for the lumbar lordosis (P < 0.001), thoracic kyphosis (P = 0.007), and spinosacral angle (P = 0.02). The Roussouly type had no effect on the postoperative course of radiographic parameters. CONCLUSION: Equivalent clinical and radiographic outcomes have been highlighted independently of the increasing of the sacral slope for patients with one-level lumbar TDR. LEVEL OF EVIDENCE: 3.