Evaluation of Percutaneous Pedicle Screw Fixation in Patients with Pyogenic Spondylitis of the Thoracolumbar Spine

Background: Basic principle for the treatment of pyogenic spondylitis (PS) is conservative care, but surgical intervention is often required when conservative treatment may fail. We have experienced many conservative cases of various complications due to long-term bed rest and poor pain control. Recently we have adopted percutaneous pedicle screw (PPS) fixation for the treatment of PS as a minimally invasive spine stabilization (MISt) fusion to reduce such morbidity of the conservative care. Objective: To evaluate the impact of PPS fixation in patients with PS. Study Design: A retrospective analysis of the medical records. Subjects, Methods: We reviewed 54 consecutive patients who underwent treatment in our hospital for PS during 2005-2018 and observed for more than 12 months. Of those we excluded cases showing effectiveness to initial treatment (it was defined fever relief or C-reactive protein (CRP) inversion in 3 weeks of antibiotics) so that this study is a retrospective study in cases showing initial treatment resistance. Finally, this study included 29 cases. Medical records of these 29 cases were reviewed for baseline, organism isolated and its detection rate, the clinical outcome in 12 months (Discharge, Transfer, Death), the period from the first visit to our hospital to fever relief, CRP inversion, ambulation, and Discharge or Transfer. Results: These cases were divided into two groups, the conservative group (C-group): 17 cases, and the PPS group (P-group): 12 cases. There is no statistically significant difference in fever relief (p = 0.051) and CRP inversion (p = 0.208). The period to ambulation and discharge or transfer was significantly shorter in group P (p = 0.020, p = 0.031). 1-Year survival rate was 92% in the P-group, and 71% in the C-group. There is no statistically significant difference (p = 0.354) between the two groups. The rate of Discharge to home and care facility is 58% in P-group, and 47% in C-group. And the rate of Transfer is 34% in P-group, and 35% in C-group. Conclusion: PPS fixation was effective to achieve shortening the period to ambulation and discharge or transfer. But it was not effective in infection control. This suggests that PPS fixation should be aggressively administered to patients who can expect pain relief and early ambulation by PPS fixation in the patient of PS showing resistance to initial treatment.

Lumbar spine superior-level facet joint violations： percutaneous versus open pedicle screw insertion using intraoperative 3-dimensional computer-assisted navigation

Background Percutaneous pedicle screw use has a high rate of cranial facet joint violations （FVs） because of the facet joint being indirectly visualized.Computer-assisted navigation shows the anatomic structures clearly,and may help to lower the rate of FVs during pedicle screw insertion.This study used computed tomography （CT） to evaluate and compare the incidence of FVs between percutaneous and open surgeries employing computer-assisted navigation for the implantation of pedicle screw instrumentation during lumbar fusions.Methods A prospective study,including 142 patients having lumbar and lumbosacral fusion,was conducted between January 2013 and April 2014.All patients had bilateral posterior pedicle screw-rod instrumentation （top-loading screws） implanted by the same group of surgeons; intraoperative 3-dimensional computer navigation was used during the procedures.All patients underwent CT examinations within 6 months postoperation.The CT scans were independently reviewed by three reviewers blinded to the technique used.Results The cohort comprised 68 percutaneous and 74 open cases （136 and 148 superior-level pedicle screw placements,respectively）.Overall,superior-level FVs occurred in 20 patients （20/142,14.1％）,involving 27 top screws （27/284,9.5％）.The percutaneous technique （7.4％ of patients,3.7％ of top screws） had a significantly lower violation rate than the open procedure （20.3％ of patients,14.9％ of top screws）.The open group also had significantly more serious violations than did the percutaneous group.Both groups had a higher violation rate when the cranial fixation involved the L5.A 1-level open procedure had a higher violation rate than did the 2-and 3-level surgeries.Conclusions With computer-assisted navigation,the placement of top-loading percutaneous screws carries a lower risk of adjacent-FVs than does the open technique; when FVs occur,they tend to be less serious.Performing a single-level open lumbar fusion,or the fusion of the L5-S1 segment,requires caution to avoid cranial adjacent FVs.