Appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine using c-arm fluoroscopy: a cadaveric study.

BACKGROUND: We studied the characteristics and regularity of appropriate insertion points for percutaneous pedicle screw placement in the lumbar spine using C-arm X-ray fluoroscopy. The purpose of this study was to improve the accuracy of percutaneous pedicle screw placement and reduce the incidence of superior-level facet joint violation. METHODS: Six normal spinal specimens were included. Three different methods for placing percutaneous pedicle screws in the lumbar spine were applied, including the Roy-Camille method, Magerl method and Weinstein method. The relationships among the insertion point, pedicle projection and proximal facet joint on C-arm X-ray films were studied. The projection morphology of the vertebral pedicle in different segments of the lumbar spine was observed. The relationship between the outer edge of the pedicle projection and the outer edge of the cranial articular process was also studied. The distance between the insertion point and the facet joint (M1), the distance between the insertion point and outer edge of the cranial articular process (M2), and the distance between the insertion point and the projection center of the pedicle (M) were measured. RESULTS: In this study, we found that the projection shape of the vertebral pedicle differed across segments of the lumbar spine: the shape for L1-L3 was oval, and that for L4-L5 was round. The radiographic study showed that the outer edge of the cranial articular process was located on the lateral side of the outer edge of the pedicle projection and did not overlap with the pedicle projection. M for the Weinstein group was larger than that for the Roy-Camille group (P <  0.05). M1 for the Weinstein group was larger than that for the Roy-Camille and Magerl groups (P <  0.05). M2 for the Roy-Camille group was negative, M2 for the Magerl group was 0, and M2 for the Weinstein group was positive. CONCLUSION: Under C-arm X-ray fluoroscopy, we were able to accurately identify the characteristics and regularity of the appropriate insertion point for percutaneous pedicle screw placement in the lumbar spine, which was important for improving the accuracy of percutaneous pedicle screw placement and reducing the incidence of superior-level facet joint violation.

Feasibility of anterior pedicle screw fixation in lumbosacral spine: a radiographic and cadaveric study.

BACKGROUND: The anterior pedicle screw (APS) technique for L5 and S1 is crucial for proper anterior lumbar interbody fusion (ALIF). This study aimed to determine the projection, screw trajectory angle, and bone screw passageway length (BSPL), as well as the screw insertion regularity and the operating area within which it is safe to perform insertion. METHODS: Forty patients with low back pain, all of whom had lumbar computed tomography scans available, was included in this retrospective analysis. Radiographic parameters were measured, including: the distances from the projection to the upper endplate, lower endplate, and midline; the transverse and sagittal screw angles; and the BSPL. In addition, 10 fresh adult cadaveric lumbosacral spine segments were selected to determine the safe anatomic area in which to operate. Finally, APSs were inserted in L5 and S1 to determine the regularity of APS insertion. RESULTS: We measured the anterior projection parameters, including: the distances to the upper endplate (L5: 12.5±1.3 mm; S1: 4.54±0.87 mm), lower endplate (L5: 17.3±1.6 mm), and midline (L5: 6.6±0.7 mm; S1: 6.6±0.6 mm); the screw trajectory angle, including the transverse screw angle (L5: 25.3±2.8°; S1: 25.7±2.6°), sagittal screw angle (L5: 17.1±1.7°; S1: 22.4±1.1°); and the BSPL (L5: 48.6±3.5 mm; S1: 48.0±3.5 mm). The regularity of APS insertion in L5 and S1 was determined. Upon the needle reaching a point in the lateral view, it reached the corresponding point in the anteroposterior (AP) view. The anatomic parameters of the safe operating area were as follows: the distance from the abdominal aortic bifurcation to the L5 lower edge (40.50±9.40 mm); the distance from the common iliac vein confluence to the L5 lower edge (27.80±8.60 mm); and the horizontal distance from the inner edge of the common iliac vein to the L5 lower edge (37.50±1.30 mm). We also determined the distance between S1 holes (29.30±1.30 mm), the L5/S1 intervertebral height (17.20±1.50 mm), and the safe operating area (2,058.20±84.30 mm2). CONCLUSIONS: This study has determined the projection, screw trajectory angle, and BSPL of APSs in L5 and S1, their insertion regularity, and the area in which the operation can be safely performed.

Multimodal Nutritional Management in Primary Lumbar Spine Surgery: A Randomized Controlled Trial.

STUDY DESIGN: A prospective randomized controlled trial. OBJECTIVE: The purpose of this study was to evaluate the clinical effect and safety of a new multimodal nutritional management (MNM) protocol for patients receiving primary lumbar spine surgery. SUMMARY OF BACKGROUND DATA: Poor nutritional status is common in the perioperative period in primary lumbar spine surgery, and may impede recovery after surgery. METHODS: A total of 187 patients were included in this prospective randomized controlled trial. They were randomly assigned to the MNM group or the control group. Albumin (ALB) infusion, postoperative ALB level, electrolyte disorders, postoperative electrolyte levels, transfusion rate, postoperative hemoglobin level, length of stay (LOS), and complications were compared between the groups. RESULTS: Compared with the control group, the rate and the total amount of ALB infusion were lower in the MNM group, and the postoperative level of ALB in the MNM group was higher on the first postoperative day, and the third postoperative day. The incidence of hypokalemia, hyponatremia, and hypocalcemia were lower in the MNM group. In the MNM group, the postoperative levels of sodium, potassium, and calcium were higher than the control group. The transfusion rate was similar between the two groups. The hemoglobin level was similar between the two groups on first postoperative day, but was higher in the MNM group on third postoperative day. LOS in the MNM group was shorter than in the control group. The incidence of wound drainage was lower in the MNM group. No statistical differences were observed regarding surgical complications between the two groups. CONCLUSION: The MNM protocol effectively reduced ALB infusion, the incidence of electrolyte disorders, and wound drainage, increased the postoperative levels of ALB, sodium, potassium, and calcium, and reduced the LOS without increasing the rate of postoperative complications. LEVEL OF EVIDENCE: 2.

[Analysis of correlative factors of spinal cord posterior displacement after single door laminoplasty].

OBJECTIVE: To observe the open angle (OA), cervical curvature angle (CA), preoperative spinal cord compression rate(PSCR), postoperative spinal cord shift (PSCS) in patients with chronic compressive cervical myelopathy undergoing C3-7 single open laminoplasty, and to explore the possible mechanism and influencing factors of postoperative average spinal cord drift, so as to provide objective basis for predicting PSCS. METHODS: From May 2012 to July 2016, 32 patients with multi-segmental chronic compressive cervical myelopathy who underwent single-door laminoplasty in our department were analyzed retrospectively, including 14 cases of cervical spondylotic myelopathy, 8 cases of developmental cervical spinal stenosis with cervical myelopathy, and 10 cases of ossification of posterior longitudinal ligament. The OA of cervical spine was measured on CT, the CA was measured on X-ray, the PSCR and PSCS were measured on MRI. The patients were divided into two groups according to PSCS(group A>=2.5 mm, group B<2.5 mm). In the group A, there were 11 males and 6 females, with an average age of (56.58±9.80) years old, a mean course of the disease of (23.52±7.86) months; while in group B, there were 6 males and 9 females, with an average age of (58.46±12.53) years old, a mean course of disease of (21.13±7.75) months. The correlation analysis between PSCS and OA, CA and PSCR was performed, and multiple linear analysis of correlated parameters was carried out. RESULTS: The OA in group A was (40.47±9.45) °, in group B was (27.84±5.67) °. The OA in group A was higher than that in group B (P<0.01), and OA was moderately correlated with PSCS (r=0.794, P=0.000). The CA was(11.56± 4.99) ° in group A and(6.64±3.28) ° in group B . The CA in group A was higher than that in group B (P<0.01), and CA was moderately correlated with PSCS (r=0.632, P=0.000). The PSCR was (27.70±2.92) % in group A , was (24.59±2.80) % in group B . The PSCR in group A was higher than that in group B(P<0.01), PSCR was moderately correlated with PSCS(r=0.667, P=0.000). The CA dependent variable was kicked out(P>0.1), and the partial regression coefficients of OA and PSCR were 0.113 and 0.059 respectively. CONCLUSIONS: PSCS is the result of OA, CA and PSCR, among which PSCR has the most important influence, OA is the second, CA is the least. PSCS can be predicted by 0.059×OA+0.113×PSCR-2.266 equation, which provides a theoretical basis for preoperative evaluation of spinal cord decompression after surgery.

[Analysis of influencing factors the postoperative axial symptoms of cervical single open-door laminoplasty].

OBJECTIVE: To explore the influencing factors and possible mechanism of axial symptoms(AS) after C3-C7 single open-door laminoplasty in patients with chronic compression cervical myelopathy. METHODS: The clinical data of 32 patients with multi-segment chronic compression cervical cord disease treated by C3-C7 single open-door laminectomy from May 2012 to July 2016 were retrospectively analyzed. Including cervical spondylotic myelopathy of 14 cases, developmental cervical stenosis complicated with cervical myelopathy of 8 cases, ossification of posterior longitudinal ligament(OPLL) of 10 cases. There were 17 males and 15 females, aged from 47 to 82 years old with an average of 57.46 year, the course of disease was 5 to 35 months with an average of 22.4 months. The opening angle(OA), cervical curvature angle(CA), preoperative spinal cord compression rate(PSCR) and postoperative spinal cord shift (PSCS) were recorded. After 2 weeks of surgery, determining whether occurred an AS condition according to the AS assessment criteria, the patients were divided into a axial symptom group and a non-axial symptom group, the general data and imaging parameters of the two groups were compared and the factors that may be postoperative AS were analyzed by binary Logistic regression analysis. RESULTS: At 2 weeks after operation, 13 patients occurred AS. There was no significant difference in gender, age and course of disease between axial symptom group and a non-axial symptom group (P>0.05). In axial symptom group, OA was(36.76±9.35)°, CA was(11.53±4.36)°, PSCR was(27.83±1.72)%, PSCS was (3.17±0.81) mm, while in non-axial symptom group, above items were (33.03±10.52)°, (7.71±4.73)°, (25.16±3.59)%, (2.43±0.95) mm, respectively, there was significant difference in CA, PSCR, PSCS between two groups(P<0.05), and there was no significant difference in OA between two groups(P>0.05). The results of the binary Logistic regression analysis of 3 parameters(OA, PSCR, PSCS) and AS showed OA and PSCR were eliminated in dependent variables, and the partial regression coefficient of PSCR was 0.311, and P=0.031. CONCLUSIONS: CA, PSCR, and PSCS are related influencing factors of AS, and PSCS is a high risk factor for AS. C4,5 nerve traction caused by posterior spinal movement, postoperative dural self-expansion causes greater traction of the spinal cord, excessive deformation of the cervical spinal cord causes autonomic nerve damage or necrosis that dominates blood vessels may be the pathogenesis of AS, but this is only a theoretical inference, and further improved experiment is necessary to verify it in the future.

The efficacy and safety of using a bipolar sealer to prevent blood loss in spine surgery: A meta-analysis.

OBJECTIVE: The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) and non-RCTs was to evaluate the effect of using a bipolar sealer to prevent surgical bleeding in spine surgery. METHODS: In June 2017, the PubMed, Embase, Cochrane controlled trials register, Web of Science, Google, and Chinese Wanfang databases were used to identify RCTs and non-RCTs comparing the effects of intraoperative placement of a bipolar sealer versus standard electrocautery with regard to blood loss and blood transfusion. Stata 12.0 software was used to perform the meta-analysis. Weighted mean differences with 95% confidential intervals (CIs) were used for continuous outcomes, and relative risks with 95% CIs were used for discontinuous outcomes. After testing for publication bias and heterogeneity across studies, the data were aggregated and assessed with a random effects model when necessary. RESULTS: In total, 6 clinical trials with 560 patients were included in this meta-analysis. The pooled results indicated that the use of a bipolar sealer decreased the estimated blood loss (MD = -165.06, 95% CI -236.73 to -93.40, P < 0.001), the need for a blood transfusion (RR = 0.46, 95% CI 0.31 to 0.68, P < 0.001), the transfusion units used (MD = -0.41, 95% CI -0.60 to -0.21, P < 0.001), the operative time (MD = -12.98, 95% CI -21.82 to -4.15, P = 0.004) and the length of hospital stay (MD = -2.77, 95% CI -5.45 to -0.10, P = 0.042). No significant difference was observed for the occurrence of infection (RR = 0.52, 95% CI 0.19 to 1.39, P = 0.192). CONCLUSION: Based on the current meta-analysis, the use of a bipolar sealer is superior to standard electrocautery for reducing intraoperative blood loss and is therefore recommend for use during spine surgery.

Application of different patella height indices in patients undergoing total knee arthroplasty.

BACKGROUND: One complication of total knee arthroplasty (TKA) is patella baja (PB). Patellar tendon shortening and joint line elevation are two main causes of PB. The purpose of this study was to determine the incidence of PB before and after TKA by measuring the patellar height and provide evidence for choosing a suitable index. METHODS: In total, 256 consecutive patients who underwent primary TKA were included in this study. Radiographic measurements were performed; the Insall-Salvati (IS) index, modified IS (MIS) index, Blackburne-Peel (BP) index, and Caton-Deschamps (CD) index were computed; and the incidence of PB was calculated before and after the operation. The consistency between the IS and MIS indices and between the BP and CD indices was analyzed. RESULTS: The preoperative incidence of true PB (TPB) and pseudo-PB (PPB) was 9.4 and 0.8%, respectively. The postoperative incidence of TPB and PPB was 10.2 and 9.0%, respectively. The consistency between the IS and MIS indices was moderate preoperatively (pre-kappa = 0.602) and postoperatively (post-kappa = 0.742). The consistency between the BP and CD indices was moderate preoperatively (pre-kappa = 0.742) and good postoperatively (post-kappa = 0.797). CONCLUSION: The incidence of PB, especially PPB, increased after TKA. The CD and BP indices are of greater importance for the diagnosis of PB after TKA. The MIS index is a better choice than the IS index to measure the length of the patellar tendon. To measure the height of the joint line, the BP index is better postoperatively and the CD index is better preoperatively.

[Case-control study on needle-knife to cut off the medial branch of the lumbar posterior ramus under C-arm guiding for the treatment of low back pain caused by lumbar facet osteoarthritis].

OBJECTIVE: To study the clinical efficacy of needle-knife to cut off the medial branch of the lumbar posterior ramus under C-arm guiding to treat low back pain caused by lumbar facet osteoarthritis. METHODS: From July 2009 to June 2011, 60 patients with low back pain caused by lumbar facet osteoarthritis were reviewed,including 34 males and 26 females, ranging in age from 39 to 73 years old,averaged 61.9 years old; the duration of the disease ranged from 6 to 120 months, with a mean of 18.9 months. All the patients were divided into two groups, 30 patients (18 males and 12 females, ranging in age from 39 to 71 years old, needle-knife group) were treated with needle-knife to cut off medial branch of the lumbar posterior ramus under C -arm guiding and the other 30 patients(16 males and 14 females, ranging in age from 41 to 73 years old, hormone injection group) were treated with hormone injection in lumbar facet joint under C-arm guiding. The preoperative JOA scores and the scores at the 1st, 12th and 26th weeks after treatment were analyzed. RESULTS: Before treatment,the JOA scores between the two groups had no significant difference (P= 0.479); after 1 week of treatment, the JOA scores between the two groups had significant difference (P= 0.040), the improvement rate of hormone injection group was superior than that of the needle-knife group,which were (58.73+/-18.20)% in needle-knife group and (71.10+/-22.19)% in hormone injection group; after 12 weeks of treatment, the JOA scores between the two groups had no significant difference(P=0.569), and the improvement rate between the two groups had no significant difference,which were (50.09+/-19.33)% in the needle-knife group and (48.70+/-18.36)%) in the hormone injection group; after 26 weeks of treatment,the JOA scores between the two groups had significant difference (P=0.000), the improvement rate of hormone injection group was superior than that of the needle-knife group,which were (48.56+/-28.24)% in needle-knife group and (15.62+/-11.23 )% in hormone injection group. CONCLUSION: Using needle-knife to cut off the medial branch of the lumbar posterior ramus could get longer efficacy than hormone injection in the treatment of lumbar facet osteoarthritis.

[Efficacy and safety of using denervation to treat the low back pain due to lumbar joint origin].

OBJECTIVE: To explore efficacy and safety of using denervation of dorsal medial branch to treat the low back pain due to lumbar joint origin. METHODS: From March 2009 to October 2010,10 patients with the low back pain due to lumbar joint origin were enrolled in this study including 6 males and 4 females with an average age of 56.4 years old (41 to 68). The average disease duration was 1.2 years (0.5 to 3). All patients were operated by blocking the dorsal medial branch. Single branch (dorsal medial branch of the involved level), dual branches (dorsal medial branches of the involved and the upper or lower level, 5 with the upper level, 5 with the lower level), three branches (dorsal medial branches of the involved and the upper and lower levels), four branches (dorsal medial branches of the involved and the upper two and lower levels) were blocked by 0.5% lidocaine 15 ml compounded with betamethasone injection 1 ml (10 mg/ml) and a cobalt ammonium injection 500 microg at the junction of the superior articular process and the transverse process. Low back pain VAS, average EMG of multifidus of the involved level and low back muscle strength were assessed and statistically compared. Low back muscle strength was measured by the back power meter. RESULTS: The mean low back pain VAS of the 10 patients in the preoperation was 6.85 +/- 1.55, in single branch blocked group was 5.80 +/- 1.05, in dual branches blocked group was 3.65 +/- 1.20, in three branches blocked group was 2.80 +/- 1.10 and in four branches blocked group was 2.75 +/- 1.15. Average EMG of multifidus was 69.25 +/- 2.13 in the preoperation,in single branch blocked group was 62.15 +/- 1.85, in dual branches blocked group was 51.25 +/- 1.28, in three branches blocked group was 47.30 +/- 1.85 and in four branches blocked group was 45.96 +/- 1.98. The mean low back muscle strength was 60 kg in the preoperation, in single branch blocked group was 55 kg,in dual branches blocked group was 48 kg, in three branches blocked group was 44 kg and in four branches blocked group was 43 kg. Among the dual branches blocked group,low back pain VAS and low back muscle strength in the dorsal medial branches of the involved and the upper level blocked showed great decline compared with those in the dorsal medial branches of the involved and the lower level blocked. CONCLUSION: It is effective by denervation of dorsal medial branch to treat the low back pain due to lumbar joint origin. There are significant difference in low back pain VAS between every two among the preoperation,single branch blocked group,dual branches blocked group and three branches blocked group. There is no significant difference between four branches blocked group and three branches blocked group. In low back muscle strength and average EMG of multifidus, compared with the preoperation group,there is no significant decline in single branch blocked and dual branches blocked group,and there is significant decline in three branches blocked and four branches blocked group. Therefore, single or dual dorsal medial branch blocked is safety. Among the dual branches blocked group, dorsal medial branches of the involved and the upper level blocked should be given priority to. There is a certain risk in three or four dorsal medial branches blocked which should be used with caution.

[Clinical study on surgical treatment for thoracolumbar burst fractures].

OBJECTIVE: To explore the choice of operative approach for thoracolumbar burst fractures and evaluate its clinical effects. METHODS: From September 2005 to March 2009, the clinical data of 94 patients with thoracolumbar burst fractures were analyzed retrospectively. Including 59 males and 35 femals with an average age of 36.8 years (ranged from 20 to 63). The fractures were classified according to Denis classification: 17 cases of type A, 32 cases of type B, 6 cases of type C, 24 cases of type D, 15 cases of type E. Neurological injuries were classified according to ASIA classification: 3 cases of grade A, 4 cases of type B, 23 cases of grade C, 38 cases of grade D, 26 cases of grade E. Among the patients, 42 cases were treated with reduction, decompression, internal fixation with pedicle-screw through posterior approach, meanwhile, of them, 18 cases with posterior-lateral bone graft fusion; 36 cases were treated with decompression, bone graft, through anterior approach, of them, 16 cases with TSRH system fixation and 20 cases with Zeplate system fixation; 16 cases (because of bone block intruded into vertebral canal leading to spinal cord compression ) were treated with anterior and posterior approach, internal fixation with pedicle-screw through posterior approach and subtotal vertebrectomy, decompression, titanium mesh cages bone graft fusion through anterior approach, meanwhile, of them, 8 cases with screw-rod and titanium steel plate system fixation. RESULTS: All patients obtained good results and were followed up from 9 to 52 months with an average of 22.8 months. Cobb angle were corrected from preoperatively (25.00 +/- 5.50) degrees to postoperatively (4.20 +/- 1.80) degrees. Height of anterior and posterior border of vertebral body improved from preoperatively (50.80 +/- 2.82)%, (79.30 +/- 3.08)% to postoperatively (94.85 +/- 1.80)%, (98.20 +/- 1.40)%, respectively. The ratio of protruded bones to the spinal canal anteroposterior diameter decreased from preoperatively (33.10 +/- 1.40)% to postoperatively (6.70 +/- 1.50)%. Sagittal abnormity were corrected; posterior convex angle and height were no markedly lost during follow-up; no internal fixation loosening and titanium mesh displacement were found. In the aspect of never function, except for 1 case of grade A there is no recovered others obtained different improvement, among them, from grade A to B was in 2 cases; B to C, D was in 2,2, respectively; C to D, E was 16,7, respectively; D to E was in 38 cases. CONCLUSION: The two factors decide surgical methods:the integrity of posterior ligamentous complex and nervous system function. Anterior approach refers to patients with incomplete spinal cord injury and anterior vertebral canal compression; posterior approach refers to patients with injury of posterior ligamentous complex; combination with anterior and posterior approach refers to patients with two injury factors.