Osteodiscitis Post- COVID-19 Infection: A Case Series

Background: Coronavirus disease (COVID-19) is an infectious disease. It affects almost all organs of the human body. Lumbar osteodiscitis is an infection of the vertebral body and disc. The association of COVID-19 with osteodiscitis has not been reported in the literature so far. The purpose of this study was to describe a series of four cases manifested as post-COVID-19 osteodiscitis.Case presentation: We performed a retrospective assessment of the clinical, radiological, and microbiological features of adult post-COVID-19 patients who underwent surgery for unstable lumbar osteodiscitis at our hospital. The mean age of patients was 45.8±7.8 years. All the patients were treated according to their clinical conditions through a combined surgical approach as laminectomy, facetectomy, pedicular screw insertion, and fusion. The clear causes of infection were not recognized by routine methods, and COVID-19 was the only common factor in patients in the last 6 to 8 weeks.Conclusions: This case series suggest that osteodiscitis could be one of the possible side effects after COVID-19 infection.

The Use of Crosslinks with Posterior Pedicular Screw Fixation in Lumbar Spondylolisthesis

Background Pedicle screw instrumentation has gained wide popularity for stabilization of spinal fusions. The use of pedicle screw fixation has increased fusion rates. The placement of segmental pedicle screws and cross-links in short segment posterior pedicle screw constructs has been shown to increase the construct stiffness in some planes. Aim of the Work to evaluate addition of crosslinks to posterior pedicular screw fixation as a modality for surgical management of lumbar spondylolisthesis. Patients and Methods This study included 50 patients with lumbar spondylolisthesis divided into two groups according to the surgical approach used in treatment. One group with Posterolateral fixation by transpedicular screws and rods and the other Group had cross-links added to the posterior construct. Results There was no significant difference in postoperative JOA score between both groups, while comparing mean of preoperative and postoperative JOA scores in each group showed a significant rise of the score in each group after surgery. There was no significant difference in the variables of postoperative sagittal alignment between both groups, while comparing mean of preoperative and postoperative sagittal alignment variables in each group revealed a significant reduction of the disc height percent in both groups, and in slip angle and lumbar lordosis angle in group B. Regarding postoperative rate and degree of improvement in the studied groups, there was no significant difference in the rate and degree of improvement between both groups. Conclusion no appreciable benefit from using cross-links was found in short-segment fixation of lumbar spondylolisthesis, where there’s no or little torsional instability encountered.

A New Test Method for in vitro Evaluation of Pedicle Screw Loosening Potential

This paper proposes a new testing method based on the toggle effect under transverse loads (cranial-caudal) to investigate the loosening potential of pedicular screw designs. A three-step in vitro testing procedure was developed to mimic the loosening mechanism of pedicular screws. Firstly, the pedicular screw of a certain design is inserted into a bone substitute model specifically designed for the test. Secondly, a controlled cyclic cranial-caudal loading is applied transversally to the longitudinal axis of the screw for three ascendent load levels (staircase) by a pre-determined number of load cycles. Lastly, each pedicular screw is adjusted and submitted to axial pull-out quasi-static testing. The results are used to calculate a loosening index that, together with statistical analysis, indicates the potential for loosening of the specific design evaluated. The proposed testing method effectively provides a simulated environment to evaluate the loosening potential of pedicular screw designs. The proposed loosening index calculation may be used to compare different pedicular screw designs. The proposed methodology was verified as a valuable tool to investigate the influence of the cranial-caudal loads on pedicular screw behavior. It offers a new alternative for use in pre-clinical studies on the loosening potential of pedicular screw designs.

Subaxial Cervical Pedicular Screw Insertion via the Nonanatomic Axis: Technical Notes and Preliminary Clinical Report

Study Design: Retrospective study. Objective: To report the technical details of subaxial cervical pedicular screw insertion via the nonanatomic axis (nAA-CPS) and evaluate its clinical safety and accuracy. Methods: The nAA-CPS technique was performed in 21 patients. Preoperative and intraoperative management-related details are described, and a manipulation protocol is presented. Clinical outcomes were used to assess the safety and accuracy of screws was evaluated using postoperative computed tomography (CT) according to the pedicle perforation grading system, and the nonanatomic pedicle transverse angle (nPTA) and nonanatomic pedicle axis length (nPAL) were assessed based on pre- and postoperative CT images. Results: According to “one constant entry point (EP) and two perpendicular trajectory angles” protocol, nAA-CPS was performed without much interference from the muscles. No intraoperative or postoperative neurovascular complications related to the technique were observed. Of the 112 inserted screws, 78 (69.64%) were assessed as grade 0, 24 (21.43%) as grade 1, 4 (3.57%) as grade 2 and 6 (5.36%) as grade 3. The overall rate of correct position (grades 0 and 1) was 91.07% (102/112), and the rate of malposition was 8.93% (10/112), including five screws implanted medially and the other five laterally. The nPTA was highly consistent on pre- and postoperative CT ( P < .05), while postoperative nPAL was significantly shorter than preoperative nPAL ( P > .05). Conclusions: Clinically, the accuracy and safety of nAA-CPS was similar to the traditional CPS technique. The protocol, derived from previous radiological studies and workshops, greatly helped standardize clinical manipulation; thus, nAA-CPS is a promising alternative to the traditional CPS.

THE COMPARISION OF RADIOLOGICAL DISTANCE DIFFERENCE BETWEEN THE PARS INTER-ARTICULARIS AND PEDICLE, AS A REPRODUCIBLE AND CONSISTENT GUIDE FOR PEDICULAR SCREW FIXATION TECHNIQUE, IN SPINAL LUMBAR SURGERIES.

The Inter-Pedicular and Inter-Pars distance was measured in a plain AP radiography (X-Ray) of 150 and 75 CT images normal patients between 18- 47 years of age. The aim of the study is to measure the normal Inter-Pedicular and Inter-Pars distance. We found that by studying the anatomical relationship between the inner or medial Pedicular border and the Pars outer or lateral border, gives the Orthopaedic Surgeon a reproducible and consistent guide towards exacting a pedicular screw placing. We found that both X-Ray and CT images shows steady increase in the Ipr and Ipd from L1 to L5, there is a minimal difference from L1-L2 and marked difference seen from L3 to L5, and showing the differences in distances are more in the males, compared to females. The Means of all the groups compared also proves that there is steady raise in the diameter of the IPR and IPD from L1 to L5, where there is dramatical and signicant change in the upward direction, noted from L3 to L5. The mean difference is almost constant from L1to L2. So this study, did essentially to help, establish that, the inner medial border of pedicle, is in near relationship to, the outer lateral border of the Pars-Interarticularis, which helps in establishing the latero-medial entry point for the pedicular screw insertion in the lumbar spine.

Subaxial Cervical Pedicular Screw Insertion via the Nonanatomic Axis: Identification of Entry Point and Trajectory Based on a Radiographic Study and Workshop

Study Design: A radiological study and workshop. Objective: To propose a novel technique for subaxial cervical pedicle screw (CPS) insertion via the nonanatomic axis (nAA) and identify a new entry point (EP) and trajectory based on a radiological study. Methods: The new EP was determined to be the center of the upper half of the lateral mass, and the nAA was defined as the line connecting the EP and center of the pedicle. CT images of 493 subaxial cervical pedicles from 51 adults were utilized. The pedicle axis length (PAL/nPAL), pedicle transverse angle (PTA/nPTA), sagittal and transverse pedicle screw depth ratio (S-DO, T-DO), and sagittal and transverse angles (S-angle, T-angle) were measured in the anatomical axis (AA) and nAA. nAA-CPS insertions were conducted on dry specimens, and the positions of the screws were graded. Results: The nPTA (22.35° ± 1.57°), nPAL (23.75 ± 2.07 mm), T-DO (45.61% ± 3.10%), and S-DO (70.46% ± 4.44%) of the nAA-CPS were significantly different from the PTA (41.86° ± 2.77°), PAL (31.98 ± 2.40 mm), T-DO and S-DO of the AA-CPS (both 100% in ideal conditions), respectively ( P < .05). The T-angle and S-angle were 92.78° ± 3.07° and 92.18° ± 3.78°, respectively. A constant EP and consistent trajectory of the nAA-CPS identified by 2 perpendicular angles were summarized and utilized as the manipulation protocols of the workshop, and a perfect position was achieved in 80.00% (24/30) of screws. Conclusion: The nAA-CPS is a novel alternative to the classic CPS technique. A constant entry point and 2 perpendicular angles in the sagittal and transverse planes for identifying the trajectory of the nAA-CPS should be taken into account in the establishment of a manipulation protocol.

Study of functional outcome in low grade spondylolisthesis operated by pedicular screw instrumentation and fusion

Background: Functional outcome following instrumental spinal surgery for spondylolisthesis inphysically energetic patients is crucial. The present study was undertaken to evaluate the functionaloutcome of low-grade spondylolisthesis accompanied by low back pain with or without radiculopathy,with standard surgical procedure posterior lumbar interbody fusion with instrumentation. Method:In this study total of 40 patients were operated on for low-grade spondylolisthesis by posteriorstabilization using a pedicular screw rod system and posterior lumbar interbody fusion. All thepatients were followed up till 6 months after surgery and functional outcomes were noted. Results:Assessment of this series it was observed that, 57.5% of the patient had excellent outcome, 37.5%had a good outcome and 97.5% of the study population had satisfactory outcome (improvement inclinical results). There was a significant improvement in pain intensity, walking, lifting, standing,sleeping after surgery. The mean ODI difference between preoperative and post-operative at 6months follow up was 36.12% (16.75). In the outcome, 62.5% of the patient consisted of severedisability and 32.5% were with moderate disability (total-95%) while postoperative 87.5% were witha minimal disability and only 2.5% of the study population had worsened i.e crippled. Conclusion:The study concluded that surgery in form of decompression with instrumentation and posteriorlumbar interbody is a safe and effective method to treat spondylolisthesis.

DOES THE USE OF DYNAMIC SURGICAL GUIDANCE ASSIST ACCURATE PEDICLE SCREW PLACEMENT IN PATIENTS WITH OSTEOPOROSIS OR OSTEOPENIA?

ABSTRACT Objective To compare the use of a dynamic surgical guide (PediGuard®) and pilot hole preparation, with the use of a probe and the aid of fluoroscopy in osteoporotic or osteopenic patients undergoing pedicular fixation of the thoracic or lumbar spine. Methods One hundred and eight patients were randomized. A pilot hole was prepared with the dynamic surgical guide (PediGuard®), or with a probe with the aid of fluoroscopy. A total of 657 vertebral pedicles (120 thoracic and 180 lumbar) were included in the study. The parameters used for the comparison were: accuracy of the pedicular screw, number of fluoroscopic shots, and change in intraoperative trajectory of the perforation after detecting pedicle wall rupture. Results In the group with use of the dynamic surgical guide, malpositioning of the pedicle screws was observed in 8 (2.6%) patients and intraoperative change of perforation trajectory in 12 (4%) patients, and there were 52 fluoroscopic shots. In the group without use of the dynamic surgical guide (PediGuard®), misplacement of the pedicle screws was observed in 33 (11%) patients and intraoperative change of perforation trajectory in 47 (13.2%) patients, and there were 136 fluoroscopic shots. Conclusion The use of the dynamic surgical guide (PediGuard®) in patients with osteoporosis or osteopenia enabled more accurate placement of pedicular screws, with less change in the intraoperative course of the perforation and less intraoperative radiation. Level of Evidence II; Randomized clinical trial of lesser quality.