Objective:

To evaluate the therapeutic effect of Isobar TTL dynamic internal fixation system on lumbar degenerative disease and to explore the postoperative fusion rate.

Methods:

The clinical data of 80 patients with lumbar degenerative disease underwent Isobar TTL dynamic internal fixation system from April 2013 to January 2016 were retrospectively analyzed. There were 39 males and 41 females, aged from 28 to 69 years old with an average of 46.4 years, 42 cases of single segment and 38 cases of double segments. Visual analogue scale (VAS), Oswestry Disability Index (ODI) and the modified Macnab criteria were used to evaluate the clinical effects. The intervertebral range of motion (ROM) and intervertebral height ratio (ISR) were measured by X-ray films. According to the standard established by SUK to evaluate the intervertebral fusion of dynamic fixed segment.

Results:

All the patients were followed up for 17 to 45 months with an average of 31.9 months, a total of 30 cases completed imaging review. VAS and ODI scores of 80 cases respectively were 9.15±1.55, 38.65±9.60 before operation, 0.55±1.18, 1.06±2.17 at 2 weeks after operation, 0.24±0.70, 0.16±0.48 at the final follow-up. The VAS and ODI scores at 2 weeks and the final follow-up were significantly lower than those preoperative(P<0.05). At the final follow-up, according to modified Macnab criteria to evaluate the clinical effect, 65 cases obtained excellent results, 14 good, 1 fair. In the 30 cases completed imaging review, the ROM of the dynamic fixed segment was decreased from (6.87±2.18)° preoperatively to (3.52±2.80)°, (3.14±2.60)° at 2 weeks after operation and at the final follow-up(P<0.05). The ROM of the adjacent segment was increased from (4.36±1.28)° preoperatively to (4.80±1.99)°, (6.54±4.83)° at 2 weeks after operation and at the final follow-up(P<0.05). The ISR of dynamic fixed segment and adjacent segment were increased from (36.73±6.36)%, (40.74±7.29)% preoperatively to (38.37±6.35)%, (41.59±7.77)% at 2 weeks postoperatively(P<0.05), and at the final follow-up were decreased to (36.58±9.53)%, (38.25±8.08)%, there was no significant difference between preoperative and the final follow-up(P>0.05). Among them, 20 cases got possible fusion and 10 cases got non-fusion, with the possible fusion rate of 66.7%.

Conclusions:

Isobar TTL dynamic internal fixation system has a good clinical effect in the treatment of lumbar degenerative disease. Although the ROM of adjacent segments is increased, it can effectively prevent the degeneration of the adjacent segments in the short term. And the dynamic fixation segment tends to fusion.