Variability of somatosensory evoked potential and motor evoked potential change criteria in thoracic spinal decompression surgery based on preoperative motor status.

BACKGROUND CONTEXT: Combined somatosensory- and motor-evoked potential (SSEP and MEP) changes for predicting prognosis in thoracic spinal surgery have been variably reported. PURPOSE: We aimed to explore the validity of combined SSEP and MEP for predicting postoperative motor deficits (PMDs) in thoracic spinal decompression surgery (TSDS) and identify a relatively optimal neurophysiological predictor of PMDs in patients based on preoperative motor status. STUDY SETTING: Retrospective study. PATIENT SAMPLE: A total of 475 patients were analyzed. OUTCOME MEASURES: A reduction in muscle strength by more than or equal to one manual muscle testing (MMT) grade postoperatively compared with the preoperative MMT grade was identified as PMDs. Postoperative motor deficits were detected by comparing the preoperative and postoperative physical examination findings in short- and long-term follow-up visits. METHODS: All patients were divided into two subgroups according to preoperative motor status. The following data were collected: (1) demographic data; (2) IONM (intraoperative neuromonitoring) data; and (3) postoperative motor outcomes. Binary logistic regression analysis was performed to assess the efficacy of IONM change to predict PMDs. A receiver operating characteristic curve (ROC) was used to establish optimal IONM warning criteria. RESULTS: Ninety-eight patients had severe preoperative motor deficits (Group S), and 377 patients did not (Group N). MEP and SSEP change was effective for predicting PMDs in the short term (p<.01) and long term (p<.01) for TSDS patients. In Group N, the cutoff values for predicting PMDs in the short term were a decrease of 65% in SSEP amplitude and 89.5% in MEP amplitude of the baseline value. Furthermore, the cutoff values for predicting PMDs in the short term were durations of change of 24.5 minutes for SSEP and 32.5 minutes for MEP. In Group S, however, the cutoff values for predicting PMDs in the short term were a decrease of 36.5% in SSEP amplitude and 59.5% in MEP amplitude of the baseline value. Moreover, the critical values for predicting short-term PMDs were durations of change of 16.5 minutes for SSEP and 17.5 minutes for MEP. CONCLUSIONS: The optimal IONM changes for prediction vary depending on preoperative motor status. Combined SSEP and MEP are excellent for predicting PMDs in TSDS.

[Effectiveness of one-stage posterior eggshell osteotomy and long-segment pedicle screw fixation for ankylosing spondylitis kyphosis combined with acute thoracolumbar vertebral fracture].

Objective: To explore the safety and effectiveness of one-stage posterior eggshell osteotomy and long-segment pedicle screw fixation in the treatment of ankylosing spondylitis kyphosis combined with acute thoracolumbar vertebral fracture. Methods: A clinical data of 20 patients with ankylosing spondylitis kyphosis combined with acute thoracolumbar spine fracture, who were treated with one-stage posterior eggshell osteotomy and long-segment pedicle screw fixation between April 2016 and January 2022, was retrospectively analyzed. Among them, 16 cases were male and 4 cases were female; their ages ranged from 32 to 68 years, with an average of 45.9 years. The causes of injury included 10 cases of sprain, 8 cases of fall, and 2 cases of falling from height. The time from injury to operation ranged from 1 to 12 days, with an average of 7.1 days. The injured segment was T 11 in 2 cases, T 12 in 2 cases, L 1 in 6 cases, and L 2 in 10 cases. X-ray film and CT showed that the patients had characteristic imaging manifestations of ankylosing spondylitis, and the fracture lines were involved in the anterior, middle, and posterior columns and accompanied by different degrees of kyphosis and vertebral compression; and MRI showed that 12 patients had different degrees of nerve injuries. The operation time, intraoperative bleeding, intra- and post-operative complications were recorded. The visual analogue scale (VAS) score and Oswestry disability index (ODI) were used to evaluate the low back pain and quality of life, and the American spinal cord injury association (ASIA) classification was used to evaluate the neurological function. X-ray films were taken, and local Cobb angle (LCA) and sagittal vertical axis (SVA) were measured to evaluate the correction of the kyphosis. Results: All operations were successfully completed and the operation time ranged from 127 to 254 minutes (mean, 176.3 minutes). The amount of intraoperative bleeding ranged from 400 to 950 mL (mean, 722.5 mL). One case of dural sac tear occurred during operation, and no cerebrospinal fluid leakage occurred after repair, and the rest of the patients did not suffer from neurological and vascular injuries, cerebrospinal fluid leakage, and other related complications during operation. All incisions healed by first intention without infection or fat liquefaction. All patients were followed up 8-16 months (mean, 12.5 months). The VAS score, ODI, LCA, and SVA at 3 days after operation and last follow-up significantly improved when compared with those before operation ( P<0.05), and the difference between 3 days after operation and last follow-up was not significant ( P>0.05). The ASIA grading of neurological function at last follow-up also significantly improved when compared with that before operation ( P<0.05), including 17 cases of grade E and 3 cases of grade D. At last follow-up, all bone grafts achieved bone fusion, and no complications such as loosening, breaking of internal fixation, and pseudoarthrosis occurred. Conclusion: One-stage posterior eggshell osteotomy and long-segment pedicle screw fixation is an effective surgical procedure for ankylosing spondylitis kyphosis combined with acute thoracolumbar vertebral fracture. It can significantly relieve patients' clinical symptoms and to some extent, alleviate the local kyphotic deformity.

Assistive diagnostic indicators for infections related to lumbar posterior interbody fusion internal fixation: platelet count and mean platelet volume.

BACKGROUND: The most severe complication after posterior single-segment lumbar interbody fusion and internal fixation (PIFIF) surgery for degenerative lumbar diseases is deep surgical site infection (DSSI). Preoperatively diagnosing such complications proves to be challenging. Platelets, as acute-phase reactants, undergo changes in response to infections and inflammation. This study aims to assess whether platelet indices can further aid in the diagnosis of DSSI. METHODS: A single-center retrospective study was conducted from January 2016 to February 2021 at Xi'an Jiaotong University-Affiliated Honghui Hospital, involving 83 patients who underwent revision surgery after PIFIF due to lumbar degenerative diseases. Among them, 24 patients were diagnosed with DSSI based on combined bacterial culture and imaging data. Preoperative complete serological indicators including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and platelet count and mean platelet volume ratio (P/M ratio) were analyzed using receiver operating characteristic (ROC) curve analysis to determine cutoff values, sensitivity, and specificity. This was done to further assess the ability of these serological indicators to identify the occurrence of DSSI after PIFIF. RESULTS: There were no significant differences in baseline demographic characteristics between the two patient groups (P > 0.05). The P/M ratio was 13.54 ± 5.05 in the aseptic revision group, while it was 19.21 ± 6.30 in the DSSI revision patients, showing a significant difference (P < 0.001). ROC curve analysis revealed that the optimal cutoff value for the P/M ratio was 17.50, with a sensitivity of 58.3% and a specificity of 78.6%. The areas under the curve (AUC) for ESR, CRP, and P/M ratio were 0.797, 0.845, and 0.756, respectively. The negative predictive value (NPV) was 87.04%, 89.47%, and 82.45%, respectively; the positive predictive value (PPV) was 58.62%, 69.23%, and 53.84%, respectively, for ESR, CRP, and P/M ratio, respectively. When P/M ratio is used in combination with ESR and CRP, the AUC is 0.887, with a sensitivity of 95.4%, specificity of 67.8%, NPV of 97.56%, PPV of 54.76%. The diagnostic performance of the model for evaluating DSSI is significantly improved compared to using ESR and CRP alone (P < 0.05). CONCLUSION: Platelets and their related serum biomarkers are closely associated with DSSI. The P/M ratio can serve as a reliable test for screening DSSI and is worth considering for inclusion in the assessment of patients at risk of developing DSSI after potential PIFIF surgery.

A Novel Technology for 3D-Printing Artificial Vertebral Bodies for Treating Lumbar Spine Adrenal Pheochromocytoma Metastases: A Case Report and Review of the Literature.

BACKGROUND: Pheochromocytoma is an adrenal medullary neuroendocrine tumor that rarely metastasizes to the spine. Currently, its specific treatment methods still present challenges. CASE DESCRIPTION: A 41-year-old male patient who underwent left total adrenalectomy due to pheochromocytoma 3 years ago presented with lower back pain, accompanied by numbness and decreased muscle strength in both legs, as well as decreased sensation. Abnormal transmittance of the L3 vertebral body could be seen on anterior-posterior and lateral lumbar X-rays, irregular bone destruction of the L3 vertebral body was found on CT, and an MRI scan showed that the tumor was located within the L3 vertebral body, protruding into the spinal canal and compressing the epidural sac. No recurrence was found in the abdomen. Preoperatively, perform local embolization of the blood vessels supplying the tumor. First, the L2-3 intervertebral disc, L3-4 intervertebral disc and L3 vertebral body were removed using an anterior approach, the whole tumor was removed, and some of the vertebrae were taken for pathological examination and replaced with a 3D-printed prosthesis. Then, four pedicle screws were placed in the bilateral pedicles of L2 and L4 using the posterior approach, pre-bent connecting rods were installed to replace the bone cortex of the lamina and articular process followed by bone graft fusion of the interlaminar and facet joints. The postoperative results were satisfactory, and there were no perioperative complications. CONCLUSION: Lumbar pheochromocytoma metastasis is rare, difficult to treat, and should be considered in spinal metastases' differential diagnoses so early diagnosis can be made based on medical history and imaging. Preoperative local vascular imaging and embolization of the blood supply vessels were performed. After total en-bloc spondylectomy of the tumor during surgery, a prosthesis was implanted and combined with pedicle screw fixation to reconstruct spinal biomechanical stability, achieving satisfactory results. Therefore, 3D printed artificial vertebral bodies are a good choice for treating adrenal pheochromocytoma lumbar metastasis. The key to successful treatment is close interdisciplinary collaboration in formulating rigorous comprehensive perioperative plans.

Diagnostic Value of Multimodal Intraoperative Neuromonitoring by Combining Somatosensory-With Motor-Evoked Potential in Posterior Decompression Surgery for Thoracic Spinal Stenosis.

Background: Intraoperative neuromonitoring (IONM) has become an increasingly essential technique in spinal surgery. However, data on the diagnostic value of IONM in predicting impending postoperative neurological deficits (PONDs) for patients who underwent posterior decompression surgery for thoracic spinal stenosis (TSS) are limited. Furthermore, patients who are at the highest risk of waveform changes during the surgery remain unknown. Our purpose was to (1) assess the diagnostic accuracy of IONM by combining somatosensory-evoked potential (SSEP) with motor-evoked potential (MEP) in predicting PONDs for patients who underwent the surgery and (2) identify the independent risk factors correlated with IONM changes in our study population. Methods: A total of 326 consecutive patients who underwent the surgery were identified and analyzed. We collected the following data: (1) demographic and clinical data; (2) IONM data; and (3) outcome data such as details of PONDs, and recovery status (complete, partial, or no recovery) at the 12-month follow-up visit. Results: In total, 27 patients developed PONDs. However, 15, 6, and 6 patients achieved complete recovery, partial recovery, and no recovery, respectively, at the 12-month follow-up. SSEP or MEP change monitoring yielded better diagnostic efficacy in predicting PONDs as indicated by the increased sensitivity (96.30%) and area under the receiver operating characteristic (ROC) curve (AUC) value (0.91). Only one neurological deficit occurred without waveform changes. On multiple logistic regression analysis, the independent risk factors associated with waveform changes were as follows: preoperative moderate or severe neurological deficits (p = 0.002), operating in the upper- or middle-thoracic spinal level (p = 0.003), estimated blood loss (EBL) ≥ 400 ml (p < 0.001), duration of symptoms ≥ 3 months (p < 0.001), and impairment of gait (p = 0.001). Conclusion: Somatosensory-evoked potential or MEP change is a highly sensitive and moderately specific indicator for predicting PONDs in posterior decompression surgery for TSS. The independent risks for IONM change were as follows: operated in upper- or middle-thoracic spinal level, presented with gait impairment, had massive blood loss, moderate or severe neurological deficits preoperatively, and had a longer duration of symptoms. Clinical Trial Registration: [http://www.chictr.org.cn]; identifier [ChiCTR 200003 2155].

Surgical treatment of the lower cervical brucellosis with osteoporosis in the northwest region of China: review of 22 cases.

OBJECTIVE: To analyze the surgical treatment of patients with cervical brucellosis with osteoporosis over a 4-year period in Northwest China. METHODS: From 2013 to 2018, 22 patients (12 males and 10 females) with lower cervical spine brucellosis (C3-C7) underwent anterior lesion debridement, decompression, bone grafting and internal fixation combined with posterior bone graft fusion and internal fixation (ADDF+PIF). The follow-up period averaged 37.4 months (ranging from 24 to 57 months). RESULTS: Involvement of 1 vertebra was observed in 3 patients, involvement of 3 vertebrae was observed in 9 patients, and involvement of 3 vertebrae was observed in 10 patients. Before surgery, 1 patient had Frankel grade B, 2 had grade C, 9 had grade D, and 10 had grade E. In the final follow-up, 12 patients had neurological deficits, 10 patients improved by one grade, 6 patients improved by two grades, and the neurological status of 6 patients remained unchanged. In all cases, it was observed that bone fusion required 6.8 months on average. The kyphosis Cobb angle was enhanced from an average of 11.5° preoperatively (range 0°-24°) to 0.13° postoperatively (range 1°-5°), and there was no vital loss of correction in the follow-up. CONCLUSIONS: ADDF+PIF is an effective and safe treatment for patients with lower cervical brucellosis with osteoporosis.

A Loading Dose of Dexmedetomidine With Constant Infusion Inhibits Intraoperative Neuromonitoring During Thoracic Spinal Decompression Surgery: A Randomized Prospective Study.

Background: The effect of a bolus dose of dexmedetomidine on intraoperative neuromonitoring (IONM) parameters during spinal surgeries has been variably reported and remains a debated topic. Methods: A randomized, double-blinded, placebo-controlled study was performed to assess the effect of dexmedetomidine (1 µg/kg in 10 min) followed by a constant infusion rate on IONM during thoracic spinal decompression surgery (TSDS). A total of 165 patients were enrolled and randomized into three groups. One group received propofol- and remifentanil-based total intravenous anesthesia (TIVA) (T group), one group received TIVA combined with dexmedetomidine at a constant infusion rate (0.5 µg kg-1 h-1) (D1 group), and one group received TIVA combined with dexmedetomidine delivered in a loading dose (1 µg kg-1 in 10 min) followed by a constant infusion rate (0.5 µg kg-1 h-1) (D2 group). The IONM data recorded before test drug administration was defined as the baseline value. We aimed at comparing the parameters of IONM. Results: In the D2 group, within-group analysis showed suppressive effects on IONM parameters compared with baseline value after a bolus dose of dexmedetomidine. Furthermore, the D2 group also showed inhibitory effects on IONM recordings compared with both the D1 group and the T group, including a statistically significant decrease in SSEP amplitude and MEP amplitude, and an increase in SSEP latency. No significance was found in IONM parameters between the T group and the D1 group. Conclusion: Dexmedetomidine delivered in a loading dose can significantly inhibit IONM parameters in TSDS. Special attention should be paid to the timing of a bolus dose of dexmedetomidine under IONM. However, dexmedetomidine delivered at a constant speed does not exert inhibitory effects on IONM data.

Safety and Efficacy of Minimally Invasive Transforaminal Lumbar Interbody Fusion Combined with Gelatin Sponge Impregnated with Dexamethasone and No Drainage Tube after Surgery in the Treatment of Lumbar Degenerative Disease.

OBJECTIVE: The aim of the present study was to use a gelatin sponge impregnated with dexamethasone, combined with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and no drainage tube after the operation for early postoperative recurrence of root pain caused by edema. METHODS: A prospective case series study was designed. From September 2015 to January 2018, eligible patients diagnosed with lumbar degenerative disease underwent MIS-TLIF combined with a gelatin sponge impregnated with dexamethasone and no drainage tube after surgery. The short-term clinical data were collected, such as visual analog scale (VAS) scores for low back pain and leg pain preoperatively and on postoperative days (POD) 1-10, time bedridden postoperatively, and length of hospital stay postoperatively. Long-term indicators include the Japanese Orthopaedic Association (JOA) score, the Oswestry Disability Index (ODI) score, and the 36-Item Short-Form Health Survey (SF-36) score, evaluated preoperatively and 1 week, 3 months, and more than 1 year postoperatively. RESULTS: Complete clinical data was obtained for 139 patients. All patients were followed up for more than 12 months (13.7 ± 3.3 months). The average bedridden period was 1.5 ± 0.4 days and hospital stays were 2.7 ± 0.9 days. The VAS score of leg and back pain on POD 1-10 were all decreased compared with preoperation (all P < 0.0001). At the last follow up, the VAS scores for back pain and leg pain (0.69 ± 0.47; 1.02 ± 0.55) and the ODI score (11.1 ± 3.5) decreased (all P < 0.0001), and the JOA score (27.1 ± 3.2) and the SF-36 (physical component summary, 50.5 ± 7.3; mental component summary, 49.4 ± 8.9) increased (all P < 0.0001) compared with preoperative values. Patients' early and long-term levels of satisfaction postoperatively were 92.8% and 97.8%, respectively. At POD 7 and the last follow-up, the improvement rate of the JOA score, respectively, was 41.8% ± 10.6% and 87.7% ± 8.2%, and clinical effects assessed as significantly effective according to the improvement rate of the JOA score was 16.5% and 66.9%, respectively. There were 2 (1.4%) cases with complications, including 1 (0.7%) case of wound infection and 1 (0.7%) case of deep vein thrombosis. There were no device-related complications or neurological injuries. CONCLUSION: Use of a gelatin sponge impregnated with dexamethasone combined with MIS-TLIF and no drainage tube after the operation, compared with previous studies, appears to be safe and feasible to reduce recurrent back pain and leg pain after decompression in the treatment of lumbar degenerative disease.

Circular RNA hsa_circ_0000282 contributes to osteosarcoma cell proliferation by regulating miR-192/XIAP axis.

BACKGROUND: Circular RNAs (circRNAs) have emerged as a novel category of non-coding RNA, which exhibit a pivotal effect on regulating gene expression and biological functions, yet how circRNAs function in osteosarcoma (OSA) still demands further investigation. This study aimed at probing into the function of hsa_circ_0000282 in OSA. METHODS: The expressions of circ_0000282 and miR-192 in OSA tissues and cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR), and the correlation between the expression level of circ_0000282 and clinicopathological features of OSA patients was analyzed. The expressions of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in OSA cells were assayed by Western blot. The proliferation and apoptosis of OSA cells were examined by CCK-8, BrdU and flow cytometry, respectively. Bioinformatics analysis, dual-luciferase reporter gene assay and RIP experiments were employed to predict and validate the targeting relationships between circ_0000282 and miR-192, and between miR-192 and XIAP, respectively. RESULTS: Circ_0000282 was highly expressed in OSA tissues and cell lines, which represented positive correlation with Enneking stage of OSA patients and negative correlation with tumor differentiation degree. In vitro experiments confirmed that overexpression of circ_0000282 markedly facilitated OSA cell proliferation and repressed cancer cell apoptosis in comparison to control group. Besides, knockdown of circ_0000282 repressed OSA cell proliferation and promoted apoptosis. Additionally, the binding relationships between circ_0000282 and miR-192, and between miR-192 and XIAP were validated. Circ_0000282 indirectly up-regulated XIAP expression by adsorbing miR-192, thereby playing a role in promoting cancer in OSA. CONCLUSION: Circ_0000282 was a novel oncogenic circRNA in OSA. Circ_0000282/miR-192/XIAP axis regulated OSA cell proliferation apoptosis with competitive endogenous RNA mechanism.

A morphometric study of the middle and lower cervical vertebral endplates and their components.

Cervical disc arthroplasty is a common method of treating cervical degenerative disease. However, the footprints of most prosthesis dimensions are obtained from data of Caucasian individuals. Besides, there is a large discrepancy between footprints of currently available cervical disc prostheses and anatomic dimensions of cervical endplates. We aimed to detail the three-dimensional (3D) anatomic morphology of the subaxial cervical vertebral endplate, utilizing high-precision, high-resolution scanning equipment, and provide a theoretical basis for designing appropriate disc prostheses for Chinese patients.A total of 138 cervical vertebral endplates were studied. Each endplate was digitized using a non-contact optical 3D range scanning system and then reconstructed to quantify diameters and surface area for the whole endplate and its components (central endplate and epiphyseal rim). The whole endplate and mid-plane concavity depth were measured.There is marked morphologic asymmetry, in that the cranial endplate is more concave than the corresponding caudal endplate, with endplate concavity depths of 2.04 and 0.69 mm, respectively. For the caudal endplates, the endplate concavity apex locations were always located in the posterior portion (81.42%), while in cranial endplates relatively even. The central endplate was approximately 60% of the area of the whole endplate and the anterior section of the ring was the widest. From C3/4 down to C6/7 discs, the vertebral endplate gradually became more elliptical. Chinese cervical endplate anatomic sizes are generally smaller than that of Caucasians. Although Korean and Chinese individuals both belong to the Asian population subgroup, the majority of anatomic dimensions differ. Singaporean cervical endplate morphology is very similar to that of Chinese patients.We performed a comprehensive and accurate quantitative description of the cervical endplate, which provide references to shape and profile an artificial cervical disc without sacrificing valuable bone stock. To design a device with footprint as large as possible to distribute the axial load, we suggest that additional attention should be paid to the marginal rim. It is essential to specifically design appropriate disc prosthesis for Chinese patients. To fit the morphologic and biomechanical variations, we also propose that the disc prostheses for different vertebral segments should be separately designed.

[Effectiveness comparison between two operations in treatment of unstable type Kümmell's disease].

Objective: To compare the effectiveness between short segmental fixation combined with vertebroplasty (SSF+VP) and short segmental pedicle screw fixation combined with bone graft (SSF+BG) in the treatment of unstable type Kümmell's disease so as to provide a reference for the selection of the surgical method. Methods: Between March 2013 and February 2015, 48 patients with unstable type Kümmell's disease who were in accordance with the inclusive criteria were included in the study. SSF+VP were used in 25 cases (SSF+VP group) and SSF+BG in 23 cases (SSF+BG group). There was no significant difference in gender, age, disease duration, bone mineral density, fracture segment, and preoperative visual analogue scale (VAS), Oswestry disability index (ODI), and kyphotic Cobb angle between 2 groups ( P>0.05). The operation time and complications related to operation were recorded; the effectiveness was evaluated by VAS, ODI, and kyphotic Cobb angle. Results: The operation time was (107.7±18.8) minutes in SSF+VP group and was (113.7±22.4) minutes in SSF+BG group, showing no significant difference between 2 groups ( t=-1.045, P=0.302). Bone cement leakage occurred in 6 cases of SSF+VP group, and incision delayed healing occurred in 1 case of SSF+BG group. All patients achieved bone graft fusion on X-ray films. The bone graft fusion time was (15.1±1.3) weeks in SSF+VP group and (15.7±1.8) weeks in SSF+BG group, showing no significant difference between 2 groups ( t=-1.361, P=0.180). The VAS, ODI, and kyphotic Cobb angle at immediate after operation and at last follow-up were significantly lower than preoperative ones ( P<0.05). The VAS, ODI, and kyphotic Cobb angle had no significant difference between at immediate and at last follow-up in SSF+VP group ( P>0.05). In SSF+BG group, VAS at last follow-up was significantly lower than that at immediate after operation ( P<0.05), but no significant difference was found in kyphotic Cobb angle and ODI ( P>0.05). SSF+VP group was significantly better than SSF+BG group in VAS at immediate after operation ( P<0.05), but SSF+BG group was significantly better than SSF+VP group at last follow-up ( P<0.05). There was no significant difference in kyphotic Cobb angle and ODI between 2 groups at immediate after operation and at last follow-up ( P>0.05). Conclusion: SSF+BG can achieve satisfactory effectiveness in the treatment of unstable type Kümmell's disease, and it has the advantages of good bony healing, obvious improvement of pain, and low complication incidence when compared with SSF+VP.

Percutaneous kyphoplasty versus posterior spinal fixation with vertebroplasty for treatment of Kümmell disease: A case-control study with minimal 2-year follow-up.

This is a retrospective case-control study.The aim of this study was to compare the surgical results of percutaneous kyphoplasty (KP) and posterior spinal fixation with vertebroplasty (PSF+VP) for treatment of Kümmell disease (KD).KD is rare form of post-traumatic delayed avascular necrosis of the vertebral body. It is reported that KP is an effect measure for treatment of KD. Some studies have recommended posterior spinal fixation with vertebroplasty for KD.A total of 100 patients with KD who underwent spinal surgery at our hospital were enrolled from January 2008 to December 2013. The inclusion criteria were monosegment lesion without neurological deficit; the segments are restricted to T11-L2; conservative treatment is invalid. The exclusion criteria were metastatic spinal tumors, infection, primary bone tumor, and multiple myeloma; bisegments and multi-segments; patients with neurological symptoms; the defect of posterior wall of vertebral body; the occupying of vertebral canal. The symptomatic vertebrae were restricted to T11-L2. Patients who were followed-up for less than 2 years after surgery were excluded. Finally, there are 25 patients in the KP group and 21 in the PSF+VP group. There were no significant differences in patient age, disease duration, or the length of follow-up between the 2 groups.Operative time (43.2 ±â€Š21.8 vs 230.6 ±â€Š87.1 minutes) was significantly longer and bleeding volume (5.3 ±â€Š3.1 vs 215.0 ±â€Š170.2 mL) significantly greater in the PSF+VP group. No significant difference between the 2 groups was observed in Visual analog scale score (VAS) (1.3 ±â€Š0.9 vs 1.2 ±â€Š0.9), Oswestry disability index score (ODI) (27.2 ±â€Š9.0 vs 26.0 ±â€Š6.3), and Cobb angle (17.0 ±â€Š7.2 vs 16.5 ±â€Š2.8). KP resulted in a shorter operation time, less bleeding volume, and fewer postoperative complications than PSF+VP.This study shows that both treatments KP and PSF+VP for KD can be safe and effective for the patients with monosegment lesion and without neurological deficit. However, KP show the advantages in a shorter surgical duration, less blood loss, and fewer postoperative complications.

Biomechanical Analysis of a Novel Prosthesis Based on the Physiological Curvature of Endplate for Cervical Disc Replacement.

STUDY DESIGN: Biomechanical analysis of a novel prosthesis based on the physiological curvature of endplate was performed. OBJECTIVE: To compare the biomechanical differences between a novel prosthesis based on the physiological curvature of the endplate and the Prestige LP prosthesis after cervical disc replacement (CDR). SUMMARY OF BACKGROUND DATA: Artificial disc prostheses have been widely used to preserve the physiological function of treated and adjacent motion segments in CDR, while most of those present a flat surface instead of an arcuate surface which approximately similar to anatomic structures in vivo. We first reported a well-designed artificial disc prosthesis based on the physiological curvature of the endplate. METHODS: Three motion segments of 24 ovine cervical spines (C2-5) were evaluated in a robotic spine system with axial compressive loads of 50N. Testing conditions were as follows: 1) intact, 2) C3-4 CDR with artificial disc prosthesis based on the physiological curvature of the endplate, and 3) C3-4 CDR with the Prestige LP prosthesis. The range of motion (ROM) and the pressures on the inferior surface of the two prostheses were recorded and analyzed. RESULTS: As compared to the intact state, the ROM of all three segments had no significant difference in the replacement group. Additionally, there was no significant difference in ROM between the two prostheses. The mean pressure on the novel prosthesis was significantly less than the Prestige LP prosthesis. CONCLUSION: ROM in 3 groups (intact group, CDR group with novel prosthesis and CDR group with Prestige LP) showed no significant difference. The mean pressure on the inferior surface of the novel prosthesis was significantly lower than the Prestige LP prosthesis. Therefore, the novel artificial disc prosthesis is feasible and effective, and can reduce the implant-bone interface pressure on the endplate, which may be one possible reason of prosthesis subsidence.

The Role of Posterior Longitudinal Ligament in Cervical Disc Replacement: An Ovine Cadaveric Biomechanical Analysis.

BACKGROUND Cervical disc replacement (CDR) has been widely used to restore and maintain mobility and function of the treated and adjacent motion segments. Posterior longitudinal ligament (PLL) resection has been shown to be efficient in anterior cervical decompression and fusion. However, less is known about the biomechanical effect of PLL removal versus preservation in cervical disc arthroplasty. MATERIAL AND METHODS Three motion segments of 24 ovine cervical spines (C2-C5) were evaluated in a robotic spine system with axial compressive loads of 50 N. These cervical spines were divided in three groups according to the following conditions: (1) intact spine, (2) C3/C4 CDR with the Prestige LP prosthesis and PLL preservation, and (3) C3/C4 CDR with the Prestige LP prosthesis and PLL removal. The ranges of motion (ROMs) were recorded and analyzed in each group. RESULTS The C3/C4 ROM in group 3 (CDR with PLL removed) increased significantly in flexion-extension and axial rotation compared with group 1 (intact spine). Moreover, in flexion-extension, the mean total ROM was significantly larger in group 3 than in group 1. All the ROM observed in group 2 (CDR with PLL preserved) did not significantly differ from the ROM observed in group 1. CONCLUSIONS Compared with intact spines, CDR with PLL removal partly increased ROM. Moreover, the ROM in CDR with PLL preservation did not significantly differ from the ROM observed in intact spines. The PLL appears to contribute to the balance and stability of the cervical spine and should thus be preserved in cervical disc replacement provided that the posterior longitudinal ligament is not degenerative and the compression can be removed without PLL takedown.