Objective

To elucidate the clinical and radiographic outcomes and complications of cortical bone trajectory (CBT) screw fixation in patients with osteoporosis at 24 months follow-up and to compare the results with those after transforaminal lumbar interbody fusion (TLIF) using traditional pedicle screw (PS) fixation.

Methods

We enrolled 124 patients and randomly assigned them to 2 groups (each group had 62 participants). The primary outcome: fusion rate, secondary outcome measures include 1) clinical outcomes: visual analog scale (VAS), Oswestry Disability Index (ODI), and Japanese Orthopaedic Association Score (JOA); 2) surgical parameters: operating duration, incision length, estimated blood loss, and drainage volume; 3) radiologic outcomes; 4) complications.

Results

At the 6- and 12-month follow-up points, similar fusion rate was observed based on CT scan in both groups (p=0.583 and 0.583). According to the clinical outcome, CBT provided significant better short-term functional status at 3 months post-operation regarding ODI and JOA score (p=0.012 and 0.000), and similar improvements in pain intensity and functional status at other follow-up point. In addition, CBT resulted in significantly better surgical characteristic. Notably, CBT fixation led to lower incidence of screw loosing in osteoporotic population (p= 0.006).

Conclusions

The CBT screw fixation for single-level lumbar fusion in patients with osteoporosis provided improvement of clinical symptoms comparable to that of TLIF using PS fixation. In addition, statistically significant lumbar stability was found in the CBT group. Since the present study, we suggest CBT screw fixation to be a reasonable and superior alternative to PS in TLIF for osteoporotic population.

Trial registration number: ChiCTR1900022658

Date of registration: 2019/4/20