OBJECTIVETo evaluate the value of transforaminal approach single interbody fusion cage combining with fixation with pedicle screws in treating lumbar instability.

METHODSFrom 2006 to 2009, 36 patients (39 interspaces) with lumbar instability were retrospectively analyzed, included 14 males and 22 females; aged from 45 to 68 years with an average of 54 years; course of disease was from 6 months to 12 years with an average of 4 years. Of them, instability in lumbar disc herniation had 8 cases, lumbar spinal stenosis 5 cases, postoperative instability in lumbar disc herniation 3 cases, lumbar spondylolysis 20 cases; unstable segment in L3,4 had 2 cases, L4,5 18 cases, L5S1 13 cases, and double segment 3 cases (both L4,5 and L5S1). All patients underwent decompression, reduction, interbody fusion with single cage from transforaminal approach with pedicle screws and posterolateral fusion. The clinical effects were evaluated according to imaging results and JOA scoring system.

RESULTSAll the patients were followed up from 8 to 32 months with an average of 18 months. The results of 38 intervertebral fusion, suspicious fusion of a vertebral space, fusion rate was 97.4% (38/39). Segmental lordosis angle after operation was increased (4.09 +/- 0.13) degrees than before operation (P < 0.01), and final follow-up was reduced (3.83 +/- 0.17) degrees than after operation (P > 0.05). JOA scoring before operation and final follow-up were respectively 8.14 +/- 1.09 and 13.54 +/- 1.19, there was statistically significant between the two periods (P < 0.01); the JOA score improvement rate (RIS): 28 cases got excellent result, 6 good and 2 fair, the rate of excellent and good was 94.4%.

CONCLUSIONThe path through the transforaminal approach single-fusion cage, implantation of pedicle screw fixation fusion surgery can simplify operations, reduce complications, and can obtain satisfactory clinical efficacy, which is an effective method for the treatment of lumbar instability.