Three-Dimensional Hounsfield Units Measurement of Pedicle Screw Trajectory for Predicating Screw Loosening in Lumbar Fusion Surgery.

Purpose: Dual-energy X-ray absorptiometry (DXA) is commonly used for evaluation of bone mineral density before spinal surgery, but frequently leads to overestimation in degenerative spinal diseases due to osteoproliferation factors. We introduce a novel method to compare the predictive ability of Hounsfield Units (HU) and DXA methods to predict screw loosening after lumbar interbody fusion surgery in degenerative spinal diseases by measuring HU of pedicle screw trajectory on computed tomography (CT) images preoperatively. Patients and Methods: This retrospective study was conducted on patients who underwent posterior lumbar fusion surgery for degenerative diseases. CT HUs measurement was performed using medical imaging software, including the cancellous region on cross-sections of the vertebral body and three-dimensional pedicle screw trajectory. Receiver operating characteristic (ROC) curve analyses were performed for the risk of pedicle screw loosening in association with the Hounsfield scale and preoperative BMD, and the area under the curve (AUC) and the cutoff values were calculated. Results: A total of 90 patients were enrolled and were divided into loosening (n = 33, 36.7%) and non-loosening groups (n = 57, 63.3%). No significant differences in age, gender, length of fixation and preoperative BMD were found between both groups. The loosening group showed lower CT HU values in the vertebral body and screw trajectory than the non-loosening group. Screw trajectory HU (ST-HU) exhibited a higher AUC value than vertebral body HU (B-HU). The cutoff values of B-HU and ST-HU were 160 and 110 HUs, respectively. Conclusion: Three-dimensional pedicle screw trajectory HU values yields a stronger predictive value than vertebral body HU values and BMD and may provide more guidance for surgery. The risk of screw loosening is significantly increased at ST-HU <110 or B-HU <160 at L5 segment.

Posterior Ligament-Bone Injury Classification and Severity Score: A Novel Approach to Predict the Failure of Anterior-only Surgery for Subaxial Cervical Facet Dislocations.

STUDY DESIGN: Clinical case series. OBJECTIVE: The aim of this study was to propose a novel posterior ligament-bone injury classification and severity (PLICS) score system that can be used to reflect the severity of subaxial cervical fracture dislocations (SCFDs) and predict the failure of anterior-only surgery; and to measure the intraobserver and interobserver reliability of this system. SUMMARY OF BACKGROUND DATA: The approach selection for SCFDs is controversial. Although the anterior approach is familiar for most surgeons, postoperative hardware failure and/or delayed cervical deformity is a nonnegligible complication. METHODS: Ten patients were randomly selected for intraobserver reliability evaluation on two separate occasions, one month apart. Another 30 patients were randomly selected, and the interobserver reliability was measured by comparing results of each case between each reviewer and averaging. To analyze the difference in the PLICS score, 354 patients fulfilled the follow-up were divided into stable and unstable groups according to whether radiologically stable was observed during follow-up. RESULTS: For the intraobserver reliability, the mean intraclass correlation coefficient for the 10 reviewers was 0.931. For the interobserver reliability, the mean interobserver correlation coefficient for the three elements was 0.863. Among 16 patients with PLICS score ≥7, two patients in the stable group manifested with severe injury of the posterior ligamentous complex (PLC); extremely unstable lateral mass fractures with or without severe injury of PLC were detected in the 14 patients of the unstable group. CONCLUSION: The proposed PLICS score system showed excellent intraobserver and interobserver reliability. When a PLICS score is >7 or 7 accompanied by extremely unstable lateral mass fractures, the risk of postoperative failure after an anterior-only reconstruction is high and supplemental posterior strengthening can be considered.Level of Evidence: 4.

The Efficacy of Teriparatide in Improving Fracture Healing in Hip Fractures: A Systematic Review and Meta-Analysis.

BACKGROUND: This systematic review and meta-analysis assessed the role of teriparatide in improving hip fracture healing and function to provide a clinical guide. METHODS: The systematic literature review identified randomized controlled trials (RCTs) and controlled studies evaluating teriparatide for elderly hip fractures. A meta-analysis was performed using RevMan version 5.3. RESULTS: This study included two RCTs and four retrospective studies comprising 607 patients, with 269 and 338 patients in the teriparatide and control groups, respectively. The quality of these six studies was moderate. Compared to the control group, teriparatide reduced the time to union (weighted mean difference (WMD) = -1.95; 95% confidence interval (CI): -3.23--0.68; P = 0.003) but did not improve the rate of fracture union at 3 months (odds ratio (OR) = 1.46; 95% CI: 0.50-4.24; P = 0.49) or 6 months (OR = 0.89; 95% CI: 0.44-1.81; P = 0.75). In addition, teriparatide did not decrease the complications, need for reoperation, mortality, rate of deformity after fracture healing, and subsequent fracture or improve hip function. CONCLUSIONS: The current limited evidence did not support that teriparatide improves fracture healing in hip fractures, due to study heterogeneity and various sources of biases. Further high-quality, large-sample trials are needed. This trial is registered with PROSPERO with registration number CRD42020152205.

Spontaneous Fusion After Cervical Disc Arthroplasty: A Case Report and Literature Review.

OBJECTIVE: To report a rare case of spontaneous fusion (SF) following cervical disc arthroplasty (CDA), to review the related literature, and to propose a new measure to prevent it. METHODS: The course of a patient with SF is described here. The potential causes, risk factors, and preventive measure of SF after CDA published in previous studies have also been reviewed and discussed. RESULTS: A 63-year-old man presented with a 6-month history of progressive neck pain and developed left C-7 radiculopathy 4 years ago. Magnetic resonance imaging revealed disc herniation at the C6-C7 levels resulting in compression of the left C-7 nerve root. The patient underwent CDA at the C6-C7 levels, during which a PRESTIGE cervical disc device was implanted. He failed to follow-up regularly as recommended postoperatively because he was completely free from the pain in his neck and left upper limb. Four years later, he was readmitted with a 2-month history of occasional neck stiffness. Plain radiographs indicated complete radiographic fusion of the C6-C7 levels with trabecular bone bridging surrounding the cervical disc prosthesis, and dynamic imaging showed no motion. He was seen at regular follow-up visits for up to 60 months without special treatment, as his symptoms of neck stiffness were minor and his symptom has not worsened since then. CONCLUSION: SF after CDA is a rare condition that can be attributed to patient- or prosthesis-related causes, and its risk factors are diverse. SF after CDA did not affect the patient's clinical outcome, and no special treatment was required for it. Practitioners should be aware of this rare complication and advise patients of the risks before performing CDA.

Intradural Lumbar Disc Herniation: A Case Report and Literature Review.

BACKGROUND: Lumbar disc herniation into the dural space is a very rare phenomenon of degenerative lumbar lesions in the elderly population, and its potential pathogenesis and natural course remain unclear. CASE DESCRIPTION: We describe a rare case of intradural lumbar disc herniation. A 68-year-old man presented with progressive lower back pain and radiating pain and numbness in both legs for 3 years. Magnetic resonance imaging revealed a large herniated disc at L4-L5. Posterior discectomy and fusion of the L4-L5 was performed after conservative treatment failed. Intraoperatively, only minimal disc fragments in the epidural space were found after meticulous probing following laminectomy of the L4-L5 vertebrae. The dorsal dura mater was saturated, tense, and bulged at the L4-L5 levels; additionally, an intradural mass was palpable and confirmed by intraoperative ultrasonography. Subsequently, dorsal middle durotomy was performed. Upon opening the dural sac, a large cauliflower-like mass similar to nucleus pulposus tissue was found near the arachnoid membrane. The mass was dissociative and could be completely resected. The dorsal dural incisions were closed after careful exploration, followed by fixation and fusion of the L4-L5 levels. Pathological examination revealed disc tissue with central balloon-type cystic degenerative changes. The patient's lower back pain and radiating pain and numbness of both legs improved remarkably postoperatively, and he became asymptomatic at 3 months postoperatively. CONCLUSION: Intradural lumbar disc herniation should be highly suspected when intraoperative findings are incompatible with findings from the preoperative imaging examination, and it could be further confirmed via intraoperative ultrasonography and pathological examination of the resected tissue from the dural space. Prompt surgery is recommended, and surgical results are usually favorable. We also reviewed the literature and discussed the potential pathogenesis, natural course, diagnosis, and treatment of intradural lumbar disc herniation.

Serum irisin associates with breast cancer to spinal metastasis.

The aim of this study was to determine whether the serum level of irisin can be a candidate to predict the spinal metastasis in patients with breast cancer.In a cross-sectional study, 148 patients were recruited. Of those, 53 (35.8%) had spinal metastasis. The baseline characteristics were compared by status of spinal metastasis. Multiple logistic regression analysis was used to determine whether the serum irisin can be a candidate for predicting breast cancer to spinal metastasis. The correlation coefficient analysis was used to confirm the correlation between the serum irisin and lipid metabolic parameters and body mass index (BMI), respectively.The serum irisin was higher in patients without spinal metastasis (7.60 ±â€Š3.80). Multivariable analysis showed that the serum irisin was protective to the presence of spinal metastasis in patients with breast cancer after adjustments of age and BMI (odds ratio, 0.873; 95% confidence interval, 0.764-0.999). Furthermore, there was a positive correlation between the serum irisin and BMI (r = 0.263). The patients with metabolisc syndrome (MetS) had a higher level in serum irisin. In addition, the higher numbers of MetS components were associated with higher serum irisin.Higher serum irisin can be a protective factor of spinal metastasis in patients with breast cancer. The BMI is positively associated with the serum level of irisin. Furthermore, patients with MetS tended to have a higher level of serum irisin.