Surgical outcome of posterior lumbar interbody fusion for lumbar lesions in rheumatoid arthritis

Transcription

1 Surgical outcome of posterior lumbar interbody fusion for lumbar lesions in rheumatoid arthritis Fujiwara H*, Kaito T**, Makino T**, Ishii T*, Yonenobu K*** Department of Orthopaedic Surgery, *National Hospital Organization, Osaka Minami Medical Center **Osaka University Graduate School of Medicine ***Graduate School of Health Care Sciences, Jikei Institute

2 Introduction morbidity: 25-90% Oda T, et al: Spine 20: , 1995 Spinal lesions in rheumatoid arthritis(ra) morbidity: 45-57% Kawaguchi Y, et al: J Spinal Disord & Techniques 16: 38-43, 2003 Myelopathy paresis sudden death Attention has be paid to: Cervical lesions >> lumbar lesions

3 Tight disease control by breakthrough pharmacotherapies: Bios, MTX etc. Improvements in ADL Prolonged life expectancy Prevalence of lumbar disease However, there exist only a few reports about the results of lumbar surgery in RA patients.

4 Purpose To clarify the clinical and radiographic results of PLIF for lumbar disorders in RA patients

5 Patients & Methods From 2005 to 2011 PLIF 2 segments F/U = 1Y Patients demographics RA (n=18) Non-RA(n=18) P Value Age(year) 65.9± ± # Sex (M/F) 2:16 8: * Smokers 16.7%(3/18) 22.2%(4/18) 1.00* Diabetic Mellitus 5.6%(1/18) 16.7%(3/18) 0.60* BMI(kg/m 2 ) 21.3± ± # BMD(T-score<-2.5SD) Lumbar spine 22.2%(4/18) 16.7%(3/18) 1.00* Femur 27.8%(5/18) 5.6%(1/18) 0.18* Clinical parameter in RA group N=36 # Mann-Whitney s U test, *Fisher s exact probability test Mean disease duration 14.0±8.5 (range, 3-25) years Administered medication PSL MTX Bios 6.4±2.8mg/ day 5.7±3.5mg/ week 5 patients Disease activity Serum-CRP 0.57±0.80mg/dl Disease activity score (DAS)-CRP 2.75±1.04 Steinblocker classification(i/ii/iii/iv) 0 / 5 / 9 / 4 Functional classification (1/2/3/4) 3 / 11 / 4 / 0

6 Radiographic evaluation Diagnostic criteria for rheumatoid spine lesions (plain x-ray examination) *Thoracolumbar rheumatoid spine lesion (TL-RSL) score Points disc space narrowing + vertebral deformity 2 disc space narrowing + erosive endplate 2 irregular vertebral deformity 2 vertebral bulging 2 vertebral anterior translation 1 vertebral lateral translation 1 10 Namiki O, et al: Nikkangeshi 9: 51-60, 1990 (in Japanese) 1. Probable TL-RSL: TL-RSL score* > 4~5 points 2. Definite TL-RSL: TL-RSL score* > 6 points

7 Radiographic evaluation Fusion rate Presence of radiographic ASD Adjacent vertebral fracture Loss of correction Kaito T, et al: J Neurosurg Spine 12: , 2010 Height change (ΔH) Angle change (ΔA) Change in translation (ΔT) Evaluation of clinical outcomes Japanese Orthopaedic Association(JOA) score : 29-points scoring system(neurological status) JOA back pain evaluation questionnaire (JOABPEQ) : patient-based QOL outcome measure Postoperative complications : Infection / motor or sensory deficit / implant failure Fukui M, et al: J Orthop Sci 14: , 2009

8 Results Radiographic evaluation parameter RA Non-RA P Value Lumbar lesion (+) : fused segment 89%(16/18) - - Lumbar lesion (+): adjacent segment 28%(5/18) - - At 1 year following surgery Fusion rate (%) 95.5%(21/22) 100%(22/22) 1.00* Radiographic ASD (%) 33%(6/18) 5.6%(1/18) 0.08* Adjacent vertebral fracture (%) 5.6%(1/18) 0%(0/18) 1.00* ΔH (mm) 2.4± ± # ΔA (degree) 2.9± ± # ΔT (mm) 0.6± ± # # Mann-Whitney s U test, *Fisher s exact probability test

9 JOA score N.S. baseline 20 at 1 year 10 0 RA non-ra JOABPEQ (at 1 year following surgery) RA (n=13) Non-RA (n=18) P Value Low back pain 90.7± ± # Lumbar function 75.6± ± # Walking ability 62.6± ± # Social life function 64.9± ± # Mental health 55.8± ± # Postoperative complications # Mann-Whitney s U test Deep wound infection 1/18 (5.6%) in RA group

10 Discussion Surgical results of lumbar fusion in RA patients Previous report Poor treatment outcomes for PLIF at the fused segment Migration of a pedicle screw: 2/7(28.6%) Collapse of grafted bone: 1/7(14.3%) Deep wound infection: 1/7(14.3%) Inaoka M, et al: Acta Orthop Trauma Surg 122: 73-79, 2002 In this study Fusion rate 100% Loss of correction Clinical outcomes RA group non-ra group Fused segment Tight disease control by advanced medication and additional treatment for osteoporosis may contributed this improved results.

11 Incidence of radiographic ASD: patients Incidence f/u Non-RA 33% (29/87) 3.6y Okuda S, et al, 2004 Non-RA 28% (24/85) 3.3y Kaito T, et al, 2010 In this study Total TL-RSL (+) Adjacent segment RA 33%(6/18) 60%(3/5) 1y Non-RA 6%(1/18) N/A 1y f/u adjacent vertebral fracture + retrolisthesis Careful attention should be paid to the ASD in RA patients who have pre-existing rheumatoid lumbar lesion.

12 Conclusions 1. We retrospectively compared the clinical and radiographic results of PLIF between RA and non-ra group. 2. At the fused segment, the clinical results and the fusion rate were approximately equal between RA and non-ra group. 3. Careful attention should be paid to the adjacent segment disease after PLIF, especially in RA patients who have pre-existing rheumatoid lumbar lesions. None of the authors has any potential conflict of interest.