Outcomes of the use of cement-augmented cannulated pedicle screws in lumbar spinal fusion

Abstract

BACKGROUND CONTEXTThere are few studies of the radio-clinical outcomes of cement-augmented cannulated pedicle screw (CPS) fixation in osteoporotic patients. PURPOSETo compare the radiological and clinical outcomes between groups receiving cement-augmented CPS and solid pedicle screws (SPS) in lumbar fusion surgery. STUDY DESIGN/SETTINGRetrospective comparative study PATIENT SAMPLEA total of 187 patients who underwent lumbar fusion surgery for degenerative spinal stenosis or spondylolisthesis from 2014 to 2019. OUTCOME MEASURESRadiological evaluation included screw failure, cage failure, rod breakage, and fusion grade at postoperative 6 months and 1 year. Pre- and postoperative visual analog scales for back pain (VAS-BP), leg pain (VAS-LP), Korean Oswestry disability index (K-ODI), and postoperative complications were also compared. METHODSOutcomes of patients with high risk factors for implant failure [old age, osteoporosis, autoimmune disease or chronic kidney disease (CKD)] who underwent open transforaminal lumbar interbody fusion with cement-augmented CPS fixation (Group C, n=55) or SPS fixation (Group S, n=132) were compared. RESULTS324 pedicle screws in Group C and 775 pedicle screws in Group S were analyzed. Group C had a significantly higher average age and lower T-score, and included more patients with autoimmune disease and CKD than group S (all p<.05). Clear zones, screw migration and loss of correction were significantly less frequent in Group C (all p<.05). Thirteen screw breakages were observed; they were only in Group C (4.0%) and all were in the proximal of the two holes. Interbody and posterolateral fusion rates were not significantly different. At last follow-up, all clinical parameters including VAS-BP, VAS-LP, and K-ODI scores had improved significantly in both groups. Postoperative complications were not significantly different in the two groups. CONCLUSIONIn lumbar fusion surgery, using cement-augmented CPS in high-risk groups for implant failure could be a useful technical option for reducing acute radiological complications and obtaining clinical results comparable to those obtained using SPS in patients with low risk of implant failure. LEVEL OF EVIDENCELevel 4