Abstract
Introduction
The purpose of our research is studying of incidence of implant instability, proximal fractures of instrumented and adjacent vertebras, and evaluation of health-related quality of life (HRQOL) parameters depending on extent of the sagittal balance correction after short fusion using a posterior approach.
Patients and Methods
A study of 83 patients with Type L (SRS-Schwab) deformity, operated in our institute was held in the period between 2008 and 2011. Patients were divided into two groups. The first retrospective group included 43 patients who underwent short fusion of lumbar curve from T12 or L1 to L5. The second prospective group consisted of 40 patients, which were treated using short fusion from T9 to S1 extending to the pelvis. Groups were evaluated with HRQOL-scales including VAS, ODI, SF36, and SRS-24. Radiographical assessment included Cobb coronal angle, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS), sagittal vertical axis (SVA). Radiographical, HRQOL-parameters and complications with a 3-year minimum follow-up were analyzed and compared between two groups. The comparisons were done by using independent sample Student t-test. A p-value of less than 0.05 was accepted as significant.
Results
In the first group the ideal sagittal balance was not achieved. The second group showed a better restoration of global spinal alignments compared with the first one (p < 0.05). The HRQOL-scores (VAS, ODI, SF36, and SRS-24) of the patients after 3 years are slightly higher in the second group, but we did not get significant difference between groups (p > 0.05). In the first group the number of complications in the form of implant instability (n = 15, 35%) consists of loosening of screws at the end of fusion (T12/L1 or L4/5). The second group was obtained by a higher number of patients with complications (n = 25, 63%) including loosening of screws at pelvis (n = 15, 37.5%), proximal fractures of upper instrumented vertebra (n = 7, 17.5%) and upper adjacent vertebra (n = 8, 20%). Incidence of implant instability and proximal fractures in the second group was statistically more frequent (p < 0.05).
Conclusion
The research showed that short fusion extending to the pelvis provided good sagittal balance, global spinal alignments, and likely HRQOL-parameters after 3 years follow-up. But, eventually, we obtained higher number of complications.