Special type of distal junctional failure exhibits pelvic incidence changes: sacroiliac joint-related pain following lumbar spine surgery.

Background: Currently, change in pelvic incidence (PI) in patients after spinal surgery have not been associated with clear clinical symptoms. This study sought to compare changes in the sagittal parameters of different patients before and after thoracolumbar spine surgery, the relationship between PI change and sacroiliac joint pain (SIJP) after surgery was clarified, and the correlation between PI change and sacroiliac joint (SIJ) activity was verified. Methods: This study retrospectively analyzed the data of patients who underwent thoracolumbar fusion at Sun Yat-sen Memorial Hospital from January 2019 to June 2021. The spinal and pelvic parameters [including pelvic tilt (PT), sacral slope (SS), PI, lumbar lordosis (LL) angle, etc.] of 409 patients with standard standing lateral radiographs before and after surgery were compared and analyzed. Postoperative follow-up of all patients with standardized SIJP assessment. The incidence of postoperative SIJP, and its correlation with sagittal parameters of the spine and pelvis, surgical methods, and the basic characteristics of patients were analyzed. The Chi-square test was used for categorical variables, the independent-sample t-test was used for generally conformed normally distributed continuous variables. Risk factors associated with the development of SIJP were analyzed using logistics regression. Correlations among SS, PI, and the 4 other sagittal parameters were analyzed using the Pearson correlation coefficient (r). Results: Postoperative PI changes tended to be larger in the lowest instrumented vertebra (LIV) (L4 and above: 1.63°; L5: 2.43°; S1: 3.83°; P<0.05) and longer fixed segment. The risk factors for SIJP included a PI >4° [odds ratio (OR) =13.051; P<0.001], LIV S1 (OR =3.378; P=0.023), and fixed total segment ≥3 (OR =2.632; P=0.038). ∆PI was significantly correlated with ∆SS in patients with non-S1 distal fixation vertebrae (R2=0.388; P<0.01), but no such correlation was found in patients with S1 distal fixation vertebrate. Conclusions: Changes in PI values after thoracolumbar spine surgery can correctly reflect the motion state of the SIJ. Excessive changes in PI (>4°) are similar to the mechanism of distal junctional kyphosis (DJK), while such changes make patients prone to SIJP following lumbar spine surgery.

[Tissue engineering vascularized bone repairing segmental femoral bone defects in rabbits].

OBJECTIVE: To investigate the effectiveness and mechanism of tissue engineering vascularized bone in repairing segmental femoral bone defects in rabbits. METHODS: Thirty-two rabbits were randomized into two groups (n = 16 each). A segmental and critical bone defect of 15 mm in length was made at left femur. In experimental group, the tissue engineering bone constructed from autologous bone marrow mesenchymal stem cells plus beta-tricalcium phosphate (beta-TCP) and vascular bundle was implanted into bony defect. In control group, there was no implantation of vascular bundle. Animals were sacrificed at 2, 4, 8 and 12 weeks post-implantation respectively. Histological observation was conducted to determine the process of new bone formation and remodeling. The expression of vascular endothelial growth factor (VEGF) in new bone was measured by immunohistochemistry, real-time PCR and Western blot. RESULTS: As indicated by histological observations over time, new bone formation increased in both groups. It was better in the experimental group than the control group at the beginning of 4 weeks. The expression level of VEGF gradually decreased in each group after an initial rise. And the expression of VEGF was significantly higher than the control group after implantation at all time points and peaked at 4 weeks. CONCLUSION: Tissue engineering vascularized bone accelerates bone repair in critical size defect model of femur in rabbit. Implantation of vascular bundle can promote the secretion of VEGF. And VEGF is an essential mediator of both angiogenesis and ossification.

[Comparative study on two different methods of lumbar interbody fusion with pedicle screw fixation for the treatment of spondylolisthesis].

OBJECTIVE: To compare the clinical outcome of transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) with pedicle screw fixation on the treatment of spondylolisthesis. METHODS: One hundred and twenty patients with spondylolisthesis who were managed in our department were retrospectively evaluated. They were categorized into TLIF group and PLIF group according to the surgical methods, with 60 cases in each group. The slippage rate, the height of intervertebral space and intervertebral foramen were measured in each patient before and after operation and were compared between the two groups correspondingly. The interbody fusion rate, JOA score and complications after operation were also determined. RESULTS: All the 120 patients were followed up for an average of 23 months (range, 16 to 35 months). Interbody bony fusion was achieved in every case and cage excursion or subsidence occurred in not any case. JOA score was rated as good or excellent in 83.3% of the TLIF cases and in 81.7% of the PLIF cases. There were no difference between the two groups (P > 0.05). Postoperative slippage rate was significantly less than preoperative ones in both groups (P < 0.01). No difference in lost of reduction at the final follow-up was found between TLIF and PLIF groups (P > 0.05). Significant increases in the height of intervertebral space and intervertebral foramen after operation were approved in both groups (P < 0.01), but no difference in these increases was confirmed between the two groups (P > 0.05). The lost of the height of intervertebral space and intervertebral foramen at the final follow-up were also similar between the two groups (P > 0.05). CONCLUSIONS: TLIF and PLIF are good methods for the treatment of spondylolisthesis, both leading to satisfactory clinical outcomes. However, TLIF is relatively safer owing to its unilateral approach for interbody fusion.

[Comparison percutaneous cervical disc nucleoplasty and cervical discectomy for the treatment of cervical disc herniation].

OBJECTIVE: To compare the therapeutic effect of percutaneous cervical disc nucleoplasty (PCN group) and percutaneous cervical discectomy (PCD group) for the treatment of cervical disc herniation. METHODS: A retrospective study was carried out from July of 2002 to December of 2004, and there were 80 cervical disc herniation cases who were operated by PCN (42 cases) or PCD (38 cases). The time of operation, clinical result and the stability of cervical spine after operation were evaluated and compared between 2 groups. RESULTS: All cases had been followed up from 6 months to 26 months, average (12 +/- 5) months on the PCN group and (12 +/- 4) months on the PCD group, and there was no significant difference on 2 groups (t = -0.06, P = 0.953). All cases had been successfully operated. There was significant difference in the operation time between 2 groups (t = -21.70, P = 0.000). There was significant difference in the pre- and post-operation scores of each group (PCN group: t = 14.05, P = 0.000; PCD group: t = -14.79, P = 0.000). There was no significant difference in 2 groups of the clinical outcomes (z = -0.377, P = 0.706, > 0.05). There was no instability of cervical spine cases in 2 groups after operation (P > 0.05), and the cervical spine stability was no significant difference in pre- and-operation in each group. CONCLUSIONS: PCN and PCD for the treatment of cervical disc herniation achieves good outcomes and no difference on the stability of cervical spine. PCN and PCD is a safe, minimally invasive, short time of operation, less traumatic operation and excellent clinical outcome.