Comparative Study of Preoperative Sagittal Spinal Pelvic Alignment in Patients with Cervical Spondylotic Radiculopathy, Ossification of the Posterior Longitudinal Ligament, and Cervical Spondylotic Myelopathy.

OBJECTIVES: Cervical spondylosis may lead to changes in the sagittal parameters of the neck and trigger compensatory alterations in systemic sagittal parameters. However, there is currently a dearth of comparative research on the changes and compensatory alterations to sagittal parameters resulting from different types of cervical spondylosis. This study compared the preoperative sagittal alignment sequences among patients with cervical spondylotic radiculopathy (CSR), ossification of the posterior longitudinal ligament (OPLL), and cervical spondylotic myelopathy (CSM) caused by factors resulting from non-OPLL factors. MATERIALS AND METHODS: Full length lateral X-ray of the spine and cervical computed tomography (CT) of 256 patients (134 men, 122 women; mean age, 56.9 ± 9.5 years) were analyzed retrospectively. A total of 4096 radiomics features were measured through the lateral X-ray by two spinal surgeons with extensive experience. The clinical symptoms measures were the Japanese Orthopaedic Association (JOA) score, number of hand actions in 10 s, hand-grip strength, visual analog scale (VAS) score. Normally distributed data was compared using one-way analysis of variance (ANOVA) for parametric variables and χ2 test were used to analyze the categorical data. RESULTS: In the OPLL group, the C2-C7 Cobb angle was greater than in the CSR and CSM groups (19.8 ± 10.4°, 13.3 ± 10.3°, and 13.9 ± 9.9°, respectively, p < 0.001). Additionally, the C7-S1 SVA measure was found to be situated in the anterior portion with regards to the CSM and CSR groups (19.7 ± 58.4°, -6.3 ± 34.3° and -26.3 ± 32.9°, p < 0.001). Moreover, the number of individuals with C7-S1 SVA >50 mm was significantly larger than the CSM group (26/69, 11/83, p < 0.001). In the CSR group, the TPA demonstrated smaller values compared to the OPLL group (8.8 ± 8.5°, 12.7 ± 10.2°, p < 0.001). Furthermore, the SSA was comparatively smaller as opposed to both the OPLL and CSM groups (49.6 ± 11.2°, 54.2 ± 10.8° and 54.3 ± 9.3°, p < 0.05). CONCLUSION: Patients with OPLL exhibit greater cervical lordosis than those with CSR and CSM. However, OPLL is more likely to result in spinal imbalance when compared to the CSM group. Furthermore, OPLL and CSM patients exhibit anterior trunk inclination and worse global spine sagittal parameters in comparison to CSR patients.

Does mild flexion of the femoral prosthesis in total knee arthroplasty result in better early postoperative outcomes?

BACKGROUND: The purpose of this study was to measure the femoral prosthesis flexion angle (FPFA) in total knee arthroplasty (TKA) using three-dimensional reconstruction, and to assess the differences in early clinical efficacy between patients with different degrees of flexion. METHODS: We conducted a prospective cohort study. From June 2019 to May 2021, 113 patients admitted for TKA due to osteoarthritis of the knee were selected. The patients' postoperative knee joints were reconstructed in three dimensions according to postoperative three-dimensional computed tomography (CT) scans. The FPFA was measured, and the patients were divided into 4 groups: anterior extension group (FPFA < 0°), mildly flexed group (0° ≤ FPFA < 3°), moderately flexed group (3° ≤ FPFA < 6°) and excessively flexed group (6° ≤ FPFA). The differences in the Knee Society Score (KSS), knee Range of Motion (ROM), and visual analogue scale (VAS) scores were measured and compared between the four groups at each postoperative time point. RESULTS: Postoperative KSS, ROM, and VAS were significantly improved in all groups compared to the preoperative period. At 1 year postoperatively, the ROM was significantly greater in the mildly flexed group (123.46 ± 6.51°) than in the anterior extension group (116.93 ± 8.05°) and the excessively flexed group (118.76 ± 8.20°) (P < 0.05). The KSS was significantly higher in the mildly flexed group (162.68 ± 12.79) than in the other groups at 6 months postoperatively (P < 0.05). The higher KSS (174.17 ± 11.84) in the mildly flexed group was maintained until 1 year postoperatively, with a statistically significant difference (P < 0.05). No significant difference in VAS scores was observed between groups at each time point. CONCLUSIONS: A femoral prosthesis flexion angle of 0-3° significantly improved postoperative knee mobility, and patients could obtain better Knee Society Scores after surgery, which facilitated the postoperative recovery of knee function. TRIAL REGISTRATION: ChiCTR2100051502, 2021/09/24.

Evaluation of the inter and intraobserver reproducibility of the "defect coverage index method", a new computed tomography assessment method of sagittal graft positioning in arthroscopic bone block procedures.

PURPOSE: To assess the reproducibility of a new 2-dimensional computed tomography (CT) method of assessing graft positioning in arthroscopic bone block procedure. METHODS: This is a prospective observational study. Twenty-seven patients, (all men, mean [Standard deviation] age at surgery 30.9 [8.49] years) were included. Vertical graft position was assessed on the sagittal view by measuring the amount of glenoid bone defect covered by the graft. The length of the bone defect and the amount of graft covering the defect were measured. Positioning of the graft on the sagittal plane was classified as accurate if the graft covered at least 90% of the defect. Intraobserver and interobserver reproducibility was analyzed using intraclass correlation coefficients (ICC) and Kappa coefficient with 95% confidence. RESULTS: Excellent intraobserver reproducibility was found, with an ICC of 0.94 (CI 95%, 0.86-0.97). Interobserver reproducibility was good, with the ICC value of 0.71, ranging from 0.45 to 0.86 (CI 95%). CONCLUSION: This new method of assessing graft positioning in arthroscopic bone block procedures on 2-dimensional computed tomography scans is reliable, with an excellent intraobserver and good interobserver reproducibility. LEVEL OF EVIDENCE: III.

Association between bone morphology and sagittal disc position in temporomandibular joints of patients with anterior disc displacement.

OBJECTIVES: To analyze the association between sagittal temporomandibular joint (TMJ) disc position of patients with anterior disc displacement evaluated by magnetic resonance imaging (MRI) and bone morphology of the TMJ evaluated by cone-beam computed tomography (CBCT). METHODS: One hundred and seventy-eight TMJs of 97 patients were retrospectively analyzed. The TMJ disc position was evaluated using MRI and classified into four types: control group (without disc displacement), slight group (disc slightly anteriorly displaced), moderate group (disc moderately anteriorly displaced), and severe group (disc severely anteriorly displaced). The measurements of TMJ bone morphology among four groups were evaluated by CBCT through Mimics software including condyle linear dimensions (condyle length, width, and height), condylar volume and surface area, and the depth and length of the glenoid fossa, joint anterior space, joint superior space, and joint posterior space. The sagittal plane position of the condyle was also assessed. The differences in all the morphologic measurement parameters among the four groups were detected using the one-way analysis of variance or the Kruskal Wallis test, and Chi-square tests. The correlations between disc sagittal position and all the morphologic measurements were also analyzed. RESULTS: There were significant differences in measurements of condyle linear dimensions, condylar volume and surface area, depth of the glenoid fossa, joint spaces, and distribution of the condyle sagittal positions among the four groups. By contrast, there were no statistical differences in terms of the length of the glenoid fossa among the four groups. Correlation analysis revealed that there is a statistically significant negative correlation among condyle linear dimensions, condylar volume and surface area, the depth of the glenoid fossa, joint superior space, and disc position. However, joint posterior space was positively correlated with disc position. CONCLUSIONS: A statistically significant correlation was determined between TMJ bone morphology and different sagittal disc positions. Degenerative changes in TMJ bone morphology clinically diagnosed should be altered, which can be the patients' marker of anterior disc displacement.

Association between Changes in Sagittal X-ray Measurements and Neck Extensor Muscle Atrophy after Cervical Laminoplasty.

BACKGROUND: To investigate the association between neck extensor muscles (NEM) atrophy and changes in the sagittal cervical X-ray measurements after cervical laminoplasty. BASIC PROCEDURES: This retrospective analysis was conducted on 64 patients who underwent cervical laminoplasty from March 2016 to March 2019. The preoperative and postoperative sagittal cervical X-ray images were measured, including the C2-C7 cobb angle, the C2-7 sagittal vertical axis (SVA), and the angle between the plane of the upper endplate of T1 vertebra and the horizontal plane (T1 slope). The preoperative and postoperative steatosis ratios of the NEM were measured using magnetic resonance images. MAIN FINDINGS: There were significant differences between the preoperative and postoperative measurements of the C2-7 cobb angle, the C2-7 SVA, and the T1 slope (P<0.05). The preoperative and postoperative steatosis ratios of each intervertebral level of the NEM also differed significantly (P<0.05). The muscle atrophy ratio at C3/4 was positively correlated with the change in the C2-7 SVA (R=0.646, P<0.001) and negatively correlated with the change in the C2-7 cobb angle (R=-0.445, P<0.001). The muscle atrophy ratio at C7/T1 was positively correlated with the T1 slope (R=0.446, P<0.001). CONCLUSIONS: Muscle atrophy was more severe at the attachment points of the NEM (C3/4, C7T1). There was a significant association between the muscle atrophy ratio and the changes in sagittal cervical X-ray measurements.