Spine Surgery and Related Research最新文献

Introduction: Pedicle screws are commonly used in fixation to treat various spinal disorders. However, screw loosening is a prevalent complication, particularly in patients with osteoporosis. Various biomechanical studies have sought to address this issue, but the optimal depth and trajectory to increase the fixation strength of pedicle screws remain controversial. Therefore, a biomechanical study was conducted using finite element models.

Methods: Three-dimensional finite element models of the L3 vertebrae were developed from the preoperative computed tomography images of nine patients with osteoporosis and nine patients without who underwent spine surgery. Unicortical and bicortical pedicle screws were inserted into the center and into the anterior wall of the vertebrae, respectively, in different trajectories in the sagittal plane: straightforward, cephalad, and caudal. Subsequently, three different external loads were applied to each pedicle screw at the entry point: axial pullout, craniocaudal, and lateromedial loads. Nonlinear analysis was conducted to examine the fixation strength of the pedicle screws.

Results: Irrespective of osteoporosis, the bicortical pedicle screws had greater fixation strength than the unicortical pedicle screws in all trajectories and external loads. The fixation strength of the bicortical pedicle screws was not substantially different among the trajectories against any external loads in the nonosteoporotic vertebrae. However, the fixation strength of the bicortical pedicle screws against craniocaudal load in the cephalad trajectory was considerably greater than those in the caudal (P=0.016) and straightforward (P=0.023) trajectories in the osteoporotic vertebrae. However, this trend was not observed in pullout and lateromedial loads.

Conclusions: Our results indicate that bicortical pedicle screws should be used, regardless of whether the patient has osteoporosis or not. Furthermore, pedicle screws should be inserted in the cephalad trajectory in patients with osteoporosis.

Introduction: Despite that lateral lumbar interbody fusion (LLIF) is a minimally invasive surgery, some patients complain of severe site pain immediately after the surgery. This study aimed to explore the extent of perioperative pain after LLIF, compare the degree of perioperative pain after LLIF with that after other surgical procedures, and evaluate the factors associated with severe pain in the early postoperative period.

Methods: In this study, 93 patients who underwent lumbar spine surgeries for lumbar degenerative diseases were analyzed. The patients were categorized into three groups based on the surgical procedure: Group L, LLIF with percutaneous pedicle screw (PPS); Group P, posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF); and Group D, posterior decompression (fenestration). The extent of low back pain was evaluated using the visual analog scale (VAS) preoperatively and from postoperative days 1 to 14.

Results: The VAS score for postoperative pain decreased in a time-dependent manner in all three groups (P<0.01). Repeated measures analysis of variance (ANOVA) showed that the VAS in Group L was significantly higher than that in Group D (P<0.01). Time point analysis revealed that the VAS scores from postoperative days 1 to 9 in Group L were significantly higher than those in Group D (P<0.05). No significant difference was observed in the VAS scores of postoperative pain between Groups L and P on all postoperative days. The VAS score for early postoperative pain in Group L was significantly correlated with the change in disc height index (P<0.05, r=0.43) and tended to be associated with the grade of preoperative disc degeneration and the VAS score of preoperative low back pain (P=0.076-0.19).

Conclusions: This study is the first to evaluate the factors associated with pain during the early postoperative period of LLIF. Although LLIF is a minimally invasive surgery, severe pain may develop in patients with significant preoperative disc degeneration or following spinal correction surgery.

Introduction: A halo vest is an immobilization device widely used to stabilize the cervical spine. Pain and infection at the skull pin insertion site are common complications, but skull perforation is rare, and most published studies are case reports. This study aimed to identify risk factors for skull perforation by comparing patients who did and did not develop perforation.

Methods: Overall thickness and the thicknesses of the internal and external laminae of the skull at the skull pin insertion sites were measured on cranial computed tomography scans of 66 patients fitted with a halo vest. The results were compared between patients who did and did not develop perforation.

Results: Four patients developed perforations. All patients with perforation were older women, and their external and internal laminae were significantly thinner than those of patients who did not develop perforation.

Conclusions: The reported causes of skull pin perforation include infection around the pin, osteoporosis, and an enlarged frontal sinus. However, most patients with perforation in the present study were older women, and the cause was the thinning of the external and external laminae.

Introduction: This study aimed to compare the outcomes of corrective fusion for adult spinal deformity (ASD) in older people using two different sagittal correction goals: the conventional formula of "pelvic incidence (PI)-lumbar lordosis (LL) mismatch <10°" and an undercorrection strategy based on the range of 10°≤PI-LL≤20°.

Methods: A total of 102 consecutive patients (11 male and 91 female patients; mean age, 72.0 years) aged above 65 years with scoliosis >20° or LL<20° who had undergone long-segment fusion from the lower thoracic spine to the pelvis for ASD and had been followed-up for a minimum of two years at our institution since March 2013 were included in this retrospective study. After excluding patients with PI-LL≤-10° on postoperative standing radiographs, the remaining patients were divided into two groups: 31 patients with 10°≤PI-LL≤20° (U group) and 63 patients with -10°

Results: The incidence of proximal junctional kyphosis and mechanical failure was not significantly different between the groups (p=0.659 and 1.000, respectively). After excluding patients who underwent reoperation due to mechanical failure, there were no differences in the Oswestry Disability Index (ODI) and each domain of the Visual Analog Scale score, Scoliosis Research Society-22r patient questionnaire (SRS-22r), or the short form 36 health survey questionnaire at the final observation between the U (n=27) and M (n=57) groups. In addition, the non-inferiority and equivalence of the U group to the M group were demonstrated in all domains of the SRS-22r and ODI. Furthermore, the superiority of the U group was demonstrated by the functional domain of SRS-22r.

Conclusions: For the sagittal correction goal in corrective fusion surgery for ASD in the elderly, strict adherence to "PI-LL mismatch <10°" is not necessary and "PI-LL≤20°" may be acceptable.

Introduction: Chemonucleolysis with condoliase is a minimally invasive treatment option for lumbar disk herniation (LDH). However, studies reporting the efficacy of condoliase in patients aged <20 years are scarce. Therefore, the present study aimed to evaluate the efficacy of condoliase therapy for LDH in the aforementioned population.

Methods: Condoliase administration was determined based on adequate informed consent. The study enrolled 138 patients (mean age, 41.3±15.4 years) with LDH who received condoliase injections with a follow-up period of 1 year. The patients were divided into Group Y (age, <20 years) and Group A (age, 20-70 years). The clinical outcomes were visual analog scale (VAS) scores for leg and back pain and Oswestry Disability Index (ODI) values. Changes in disk height and degeneration were evaluated. These data were obtained at baseline and at the 3-month and 1-year follow-ups. Condoliase therapy was considered to be effective if it improved the VAS score for leg pain by ≥50% at 1 year from baseline and prevented surgery.

Results: Groups Y and A consisted of 15 and 123 patients, respectively. Condoliase therapy was effective in 9 patients (60.0%) in Group Y and 96 patients (78.0%) in Group A. The rates of Pfirrmann grade deterioration and recovery were substantially higher in Group Y than in Group A (83.3% vs. 45.8% and 50.0% vs. 16.3%, respectively). While the disk height reduction in Group Y was greater at 3 months, it recovered to the same level as that in Group A at 1 year. In Group Y, patients who did not respond to the treatment exhibited a considerably higher preoperative ODI (P<0.05).

Conclusions: Chemonucleolysis with condoliase is considered to have limited efficacy in patients aged <20 years. Caution should be taken when managing cases showing lumbar instability or existing disability. While chemonucleolysis with condoliase is a less invasive treatment option for LDH, the administration should be decided upon with sufficient consent considering the potential limited efficacy and disk degeneration.

Introduction: The association between postoperative patient-reported outcomes (PROs) and patient satisfaction remains poorly defined in patients undergoing surgery for thoracic myelopathy. This study aimed to investigate PROs and patient satisfaction following surgical intervention for thoracic myelopathy.

Methods: A prospective cohort of 133 patients who underwent surgery for thoracic myelopathy at 13 hospitals between April 2017 and August 2021 was enrolled. Patient demographics and perioperative complications were recorded. PROs were assessed using questionnaires administered preoperatively and 1 year postoperatively, including the EuroQol-5 dimension, physical and mental component summaries of the 12-item Short-Form Health Survey, Oswestry Disability Index, and numerical rating scales for low back, lower extremity, and plantar pain. Patients were categorized into two groups: satisfied (very satisfied, satisfied, and slightly satisfied) and dissatisfied (neither satisfied nor dissatisfied, slightly dissatisfied, dissatisfied, and very dissatisfied).

Results: The mean age of the patients was 66.5 years, comprising 87 men and 46 women. The most common diagnoses were ossification of the ligamentum flavum (48.8%) and thoracic spondylotic myelopathy (26.3%). Seventy-four (55.6%) and 59 (44.3%) patients underwent decompression surgery and underwent decompression with fusion, respectively. Eight patients required reoperation due to postoperative surgical site infection, hematoma, and insufficient decompression in four, three, and one patient. Ninety (67.7%) patients completed both the preoperative and postoperative PRO questionnaires, all of which demonstrated significant improvement. Among them, 58 (64.4%) and 32 (35.6%) reported satisfaction and dissatisfaction with their treatment, respectively. The satisfied group showed superior improvement in PROs than the dissatisfied group, although there were no significant differences in complication rates between the two groups.

Conclusions: The 64.4% satisfaction rate observed in patients undergoing surgery for thoracic myelopathy was lower than that reported in previous studies on cervical or lumbar spine surgery. The dissatisfied group exhibited significantly poorer quality of life (QOL) and higher pain scores than the satisfied group.