Comparative Effectiveness Of Hybrid Surgery With PEEK Rod And Fusion Surgery With Titanium Rod In The Treatment Of Lumbar Degenerative Disease

Objective To investigate the feasibility of hybrid surgery using PEEK rods pedicle screw system and the effect of different operation methods on the adjacent segment degeneration.Methods From October 2013 to October 2014,due to two-level lumbar degenerative disease,there were 21 patients for hybrid surgery with PEEK rods(nonfusion at the proximal segment,PEEK group),including 5 male patients and 16 female patients with the average 54.5 years old,14 cases fixed at L3-L5 and 7 cases at L4-S1,9 cases with lumbar disc herniation,5 cases with lumbar spinal stenosis,4 cases with lumbar disc herniation combined lumbar instability,3 cases with lumbar canal stenosis combi ned lumbar instability,and 23 cases for fusion surgery(titanium group),including 7 men and 16 women with the average 59.4 years old,14 cases fixed at L3-L5 and 9 cases at L4-S1,7 cases diagnosed with lumbar disc herniation,4 cases with lumbar spinal stenosis,4 cases with lumbar disc herniation complicated with lumbar spinal stenosis,2 cases with lumbar disc herniation complicated with lumbar instability,4 cases with lumbar spinal stenosis complicated with lumbar instability).The clinical efficacy was evaluated by Japanese Orthopedic Association(JOA)score,Oswestry Disfunction Index(ODI)and the pain visual analogue scale(VAS)score.The adjacent segment degeneration was observed by measuring the disc height index and the range of motion for adjacent segments.CT for the last follow-up was used for evaluation of lumbar interbody fusion.Results All the 44 patients were followed up.The mean follow-up period in the PEEK group and titanium group was 30.3(26-36)months and 29.1(24-36)months,respectively.The mean operation time were 128 + 17 min in the PEEK group and 147 + 19 min in the titanium group.The mean blood loss were 316 + 50 ml in the PEEK group and 364 + 51 ml in the titanium group.All of the index of clinical curative effect(JOA、ODI、VAS for back and leg)were significantly improved at the last follow-up(P<0.05),but no significant difference between the groups(P>0.05).The ROM of the proximal adjacent segment in the PEEK group was increased from 4.9°±3.6°preoperatively to 5.6°±1.9°at the last follow-up(P>0.05),and from 4.3°±2.4°to 8.1°±3.3° in the titanium group increased.The DHI of the proximal adjacent segment in the PEEK group decreased from 38%±8% preoperatively to 36%±6% at the last follow-up(P>0.05),and 36%±7% to 31%±6% in the titanium group(P<0.05).There were 6 cases with ASDeg at the proximal adjacent segment(26%)observed in the titanium group,including the progression of Pfirrmann degeneration in 5 cases,and the ROM more than 15 degrees in 1 case.1 case of the 6(4%)has clinical symptom.In the PEEK group,no ASDeg was found.The fusion rate in the PEEK group and titanium group was 85.7%(18/21)and 82.6%(38/46),respectively.In the PEEK group,one patient presented screw loosening,and also one in the Ti group.But Both of them have no clinical symptom.No surgical site infection or broken nails was encountered.Conclusion Clinical efficacy of PEEK rod for hybrid and titanium rod for fusion surgery in two-level lumbar degenerative diseases were both satisfactory.Through more than 24 months follow-up,the results showed hybrid surgery with PEEK rods has obvious advantages in preventing the degeneration of adjacent segments compared with titanium rod fusion.