Introduction: Patient selection for disc prosthesis is of an utmost importance. Since facet joint arthritis at the segment to be operated is considered as a contraindication for disc prosthesis by most authors, objective evaluation of facet joint condition seems crucial. To detect the presence of facet arthritis as a source of back pain, some surgeons depend on the evaluation of facet joint appearance in CT and/or MRI. Others perform diagnostic facet joint infiltration. However, this is a subjective procedure and its reliability is questionable. Aim of study: To assess the value of the PET-CT as an objective diagnostic tool in assessment of facet joint condition for patients undergoing Lumbar Disc Replacement (LDR).
Material/Methods: In a prospective study, 56 consecutive patients underwent LDR between Nov. 2002 and March 2008. Mean age was 40.07 years, 31 patients were females and 25 males. The preoperative diagnosis was degenerative disc disease in 42 patients, disc prolapse in 7 patients, postnucleotomy syndrome in 6 patients, and foraminal stenosis in 1 patient. Pre-and post operative clinical evaluation of the patients ODI, and VAS and working status. The radiological evaluation included plain X- rays and MRI. In this study we have used the PET-CT as an objective diagnostic tool for the detection of facet joint arthrosis. The quantitative assessment of the metabolic activity of the facet articular surface is measured. By keeping a cut -off value of 1.25 {the ratio of Standardized Uptake Value of F-18 sodium fluoride (F-18 NaF) between the joint suspected to be arthritic and the contralateral side and /or another control normal segment}. Only patients in whom PET-CT showed negative results at the target segment (i.e. SUV ratio less than 1.25) underwent lumbar disc prosthesis surgery. This cut-off value of 1.25 was identified after comparing the joints with abnormal uptake of the (F-18 NaF) with the contralateral facet joint and with control normal segment in 14 suspected segments of 10 patients .The follow up period (24-60 months) with mean of 37 months.
Results: The mean preoperative ODI was 31.9 that was decreased postoperatively to 12.5 points. The VAS for back pain |
