Screw fixation failure after 360° fusion at the lumbar level

Abstract

Aim: to identify possible predictors of screw loosening (SL) in patients after decompression and fusion at the lumbar level for degenerative spinal diseases.
 Methods. The data of patients with degenerative lumbar diseases who underwent primary decompression and fusion and who were re-hospitalized were analyzed. Clinical data (demography, characteristics of primary surgical procedures and characteristics of the perioperative period), results of radiological methods (presence and characteristics of resorption around screws, bone density (BMD) by densitometry and CT, intervertebral fusion grade and implant subsidence) were evaluated.
 Results. The study included 19 patients with SL and 37 patients without resorption, median age 59.1 [51.4; 63.1] years, men 20 (35.7%). When comparing patients with and without SL, there was no significant difference in gender, age, method of surgery, length of the fixation (p 0.05). According to CT scans, the bone density of the vertebrae between the groups did not differ significantly (p 0.05). In the group with SL, fusion failure was more common than in the group without SL (22.6% versus 20.7%), but the differences are not significant (p 0.05). In the intergroup comparison, it was determined that, in general, there were more complications in the group with SL than in the group without SL (p = 0.00015) due to the greater number of infectious complications (p = 0.00044). Also, patients with SL had a significantly longer duration of primary hospital stay (p = 0.000021).
 Conclusion. Patients with SL after primary surgery have a significantly longer hospital stay duration, mainly (45.8%) due to infectious complications. Patients with SL have comparable bone density in both the vertebral bodies and pedicles compared to patients without SL.