ABSTRACT
Aim: Interspinous process device (IPD) placement is an attractive treatment option for lumbar spinal and foraminal stenosis. The goal of the treatment is to release the stress on facets joints as well as decompress the nerve roots by enlarging the intervertebral foramina and narrowed canal recesses. Purpose: To evaluate possible structural changes in the lumbar spine after implantation of an IPD on operated and adjacent segments. Patients and Methods: Twenty-two patients were enrolled in the study. Preoperative MRI scans of the lumbar spine evaluated recess and foraminal stenosis prior to the application of an IPD. CT exams were performed and morphometric measurements were made to assess the size of intervertebral foramina after implantation on the operated and adjacent segments. Results: Statistically significant enlargements in diameter and surface area of the intervertebral foramen were seen at the operating level. On the right and left sides, foraminal enlargement after the procedure was 1 mm in diameter. The average enlargement of the foramina surface area at the level of implantation was 10 mm2. The median interspinous distance was significantly enlarged by 3.5 mm. No significant changes in adjacent segments were observed. Clinical improvement was confirmed by the Oswestry Disability Index (ODI) and visual analog scale (VAS). Preoperative disability was reduced (mean ODI from 70.5 (12.25) to 49.5 (23.75)), as well as back pain (mean VAS from 8.0 (1.7) to 4.4 (2.6)) and pain in lower limbs (mean VAS from 7.4 (1.9) to 3.8 (2.9)). Conclusion: Decompression surgery using an IPD is effective in the treatment of lumbar foraminal and canal stenosis. It provides relief of symptoms in short-term observation through enlargement of intervertebral foramina and decompression of neural roots. It reduces overload of facet joints of the operated segment and does not decrease the size of the intervertebral foramina and disc heights of adjacent segments.
ABSTRACT
BACKGROUND: The introduction of modern sub-perception modalities has improved the efficacy of spinal cord stimulation (SCS) in refractory pain syndromes of the trunk and lower limbs. The objective of this study was to evaluate the effectiveness of low and high frequency SCS among patients with chronic pain. MATERIAL AND METHODS: A randomised, semi-double-blind, placebo controlled, four period (4 × 2 weeks) crossover trial was conducted from August 2018 to January 2020. Eighteen patients with SCS due to failed back surgery syndrome and/or complex regional pain syndrome were randomised to four treatment arms without washout periods: (1) low frequency (40-60 Hz), (2) 1 kHz, (3) clustered tonic, and (4) sham SCS (i.e., placebo). The primary outcome was pain scores measured by visual analogue scale (VAS) preoperatively and during subsequent treatment arms. RESULTS: Pain scores (VAS) reported during the preoperative period was M (SD) = 8.13 (0.99). There was a 50% reduction in pain reported in the low frequency tonic treatment group (M (SD) = 4.18 (1.76)), a 37% reduction in the 1 kHz treatment group (M (SD) = 5.17 (1.4)), a 34% reduction in the clustered tonic settings group (M (SD) = 5.27 (1.33)), and a 34% reduction in the sham stimulation group (M (SD) = 5.42 (1.22)). The reduction in pain from the preoperative period to the treatment period was significant in each treatment group (p < 0.001). Overall, these reductions were of comparable magnitude between treatments. However, the modality most preferred by patients was low frequency (55% or 10 patients). CONCLUSIONS: The pain-relieving effects of SCS reached significance and were comparable across all modes of stimulation including sham. Sub-perception stimulation was not superior to supra-perception. SCS was characterised by a high degree of placebo effect. No evidence of carryover effect was observed between subsequent treatments. Contemporary neuromodulation procedures should be tailored to the individual preferences of patients.
ABSTRACT
Transpedicular stabilization is a frequently used spinal surgery for fractures, degenerative changes, or neoplastic processes. Improper screw fixation may cause substantial vascular or neurological complications. This study seeks to define detailed morphometric measurements of the pedicle (height, width, and surface area) in the aspects of screw length and girth selection and the trajectory of its implantation, i.e., sagittal and transverse angle of placement. The study was based on CT examinations of 100 Caucasian patients (51 women and 49 men) aged 27-75 with no anatomical, degenerative, or post-traumatic spine changes. The results were stratified by gender and body side, and they were counter compared with the available literature database. Pedicle height decreased from L1 to L4, ranging from 15.9 to 13.3 mm. Pedicle width increased from L1 to L5, extending from 6.1 to 13.2 mm. Pedicle surface area increased from L1 to L5, ranging from 63 to 140 mm2. Distance from the point of entry into the pedicle to the anterior surface of the vertebral body, defining the maximum length of a transpedicular screw, varied from 54.0 to 50.2 mm. Variations concerning body sides were inappreciable. A transverse angle of screw trajectory extended from 20° to 32°, shifting caudally from L1 to L5, with statistical differences in the L3-L5 segments. A sagittal angle varied from 10° to 12°, without such definite relations. We conclude that the L1 and L2 segments display the most distinct morphometric similarities, while the greatest differences, in both genders, are noted for L3, L4, and L5. The findings enable the recommendation of the following screw diameters: 4 mm for L1-L2, 5 mm for L3, 6 mm for L4-L5, and the length of 50 mm. We believe the study has extended clinical knowledge on lumbar spine morphometry, essential in the training physicians engaged in transpedicular stabilization.
