Introduction: To evaluate and compare the postoperative outcomes of Balloon Kyphoplasty (BKP) and Vertebral Body Stenting (VBS) for patients with osteoporotic vertebral fractures (OVF).

Methods: A total of 337 patients with OVFs were included. Of these, 254 patients were treated with BKP (Group B) and 83 patients with VBS (Group V). The evaluation items in this study were as follows: 1. operation time, 2. blood loss, 3. bone cement usage, 4. cement leakage, 5. Numerical Rating Scale (NRS), 6. anterior and posterior height of the fractured vertebral body, 7. wedge angle of the fractured vertebral body, 8. local kyphosis angle (items 5-8 were assessed preoperatively, immediately after the operation, and at 3 months and 1 year postoperatively; the amount of change was also recorded), and 9. adjacent vertebral fractures (at 3 months and 1 year postoperatively).

Results: There were no significant differences between the two groups in the NRS at 1 year postoperatively (Group B: 0.67, Group V: 0.69, p = 0.562) or in the incidence of adjacent vertebral fractures (Group B: 15.7%, Group V: 21.0%, p = 0.444). Operative time was significantly longer in Group V than in Group B (Group B: 35.0 min, Group V: 39.6 min, p< 0.001). Blood loss was significantly greater in Group V than in Group B (Group B: 4.5 ml, Group V: 10.6 ml, p< 0.001). Cement usage was lower in Group V (Group B: 8.7 ml, Group V: 7.7 ml, p< 0.001). There were no significant differences in the changes in radiographic measurement values from preoperatively to 1 year postoperatively.

Conclusions: There was no significant difference in clinical or radiographical outcomes between BKP and VBS.

Introduction: Postoperative posterior shift of the spinal cord in cervical laminoplasty affects postoperative outcomes and the occurrence of complications. On the other hand, a decrease in the longitudinal distance of the cervical spine due to intervertebral disc degeneration is thought to cause spinal cord redundancy and affect postoperative outcomes, but the relationship with posterior shift of the spinal cord is unknown. The purpose of this study is to investigate the relationship between the longitudinal distance of the cervical spine and posterior shift of the spinal cord.

Methods: This study included 88 patients with cervical spondylotic myelopathy who underwent cervical laminoplasty. The longitudinal distance index reported by Chiba et al. was used as an index to indicate the longitudinal distance of the cervical spine. Magnetic resonance imaging was performed before and the day after surgery, and the amount of posterior translation of the spinal cord was measured at C4/5, C5, and C5/6. The morphology of the posterior shifted spinal cord was also classified as anterior convex, straight, or posterior convex. The correlation between Longitudinal distance index (LDI) and posterior spinal cord shift, and LDI and postoperative spinal cord morphology were compared. Furthermore, the correlation between LDI and Japanese orthopedic association (JOA) recovery rate was compared.

Results: The mean LDI was 5.36 (range, 4.36-6.34). Posterior spinal cord shift was 3.36 mm (0.2-6.7) at C4/5, 3.68 mm (0.5-7.2) at C5, and 3.62 mm (0.1-6.5) at C5/6. A negative correlation was observed between LDI and posterior spinal cord translation at C5 and C5/6. The spinal cord morphology changed from preoperative anterior convex to posterior convex in 26.1% of cases and from preoperative straight to posterior convex in 55.2% of cases. Postoperative spinal cord morphology showed a significantly smaller LDI in posterior convex cases. A negative correlation was observed between LDI and JOA recovery rate.

Conclusions: It is believed that those with a short the longitudinal distance of the cervical spine have spinal cord redundancy, resulting in a large amount of posterior shift, and sufficient decompression may be achieved even in cases of cervical kyphosis.

Introduction: We examined the pre- and postoperative pain in 172 patients with adolescent idiopathic scoliosis (lenke 5, 6) who were operated at our hospital.

Methods: The subjects were 179 patients who underwent surgery at our hospital since 2008. The average age at the time of surgery was 15.8 years (11-22 years), and the average preoperative Cobb angle was 51.8° (33-87°). Preoperative pain, sex, age at surgery, age at last observation, preoperative Cobb angle, and SRS pain domain were investigated.

Results: Of the 99 out of 179 cases in which preoperative pain was noted in the medical record, SRS, or ODI, the average SRS pain domain in 71 cases confirmed by SRS or ODI was 4.3 and ODI was 4.4. Complaints of pain could not be confirmed in 49 of 71 patients, with an average SRS pain domain of 4.4 and ODI of 4.5. Gender, age at surgery, and imaging parameters did not correlate with the presence or absence of preoperative pain. Of the 163 patients who were followed up for at least 2 years postoperatively, 125 patients had pain in SRS and ODI 2 years after surgery (SRS pain domain average 4.4, ODI 3.9), and pain was recognized at the final follow-up in 114 patients (SRS pain domain mean 4.4, ODI 4.8). Of the 88 of 163 patients who had preoperative pain, 18 (20.4%) had worsened postoperative pain, and improved after surgery. On the other hand, of the 75 patients who had no pain before surgery, 53 developed new pain after surgery (SRS pain domain mean 4.4, ODI 4.7). No correlation was found between correction rate, fusion range, and number of fused intervertebral discs in relation to the onset and changes in pain.

Conclusions: 55.3% Lenke 5 and 6 patients had preoperative pain. However, only 49 out of 179 patients reported pain to their doctors, suggesting that SRS30 and ODI may have overestimated pain. More detailed studies are required, such as confirmation of the pain site, comparison with healthy subjects of the same age, and mental state.

Introduction: We developed a three-dimensional image analysis method to evaluate ossification of the posterior longitudinal ligament (OPLL) of the cervical spine, including volumetric changes over time. Using this method, we identified the rate and risk factors associated with ossification progression. In this study, we extended an initial cross-sectional analysis (based on two volume measurements) into a longitudinal study by incorporating a third measurement. Both non-surgical and surgical groups were included.

Methods: A total of 64 patients who were followed at our hospital and affiliated facilities between 2005 and 2020 were included. The non-surgical group (N group) consisted of 15 patients (7 males, 8 females), with a mean age of 62 years (range: 30-73 years). The laminoplasty group (LP group) included 28 patients (20 males, 8 females), with a mean age of 65 years (range: 44-79 years). The posterior fusion group (F group) consisted of 21 patients (15 males, 6 females), with a mean age of 62 years (range: 49-85 years). Image analysis was conducted three times for each patient, with intervals of more than one year between measurements, to measure the volume of ossification and the annual rate of increase among the three groups.

Results: Ossification volumes for the N group were 1,818 mm³, 1,917 mm³, and 1,989 mm³ at the first, second, and third measurements, respectively. For the LP group, volumes were 2,802 mm³, 2,971 mm³, and 3,152 mm³. In the F group, the values were 2,436 mm³, 2,552 mm³, and 2,634 mm³. All groups showed a significant increase in ossification volume over time (all p < 0.01), except between the second and third measurements in the F group.

The mean annual rate of increase was 4.0% in the N group, 6.6% in the LP group, and 2.2% in the F group. There was a trend towards a lower progression rate in the F group (p = 0.06). Changes in the annual rate of increase from the first to the second and second to the third measurements was 4.5% and 3.5% in the N group, 6.5% and 6.6% in the LP group, and 2.7% and 1.6% in the F group, respectively, with only group F showing a significant decline over time (p < 0.05).

Conclusions: The annual progression rate of OPLL followed the order: F group < N group < LP group, corresponding to approximate annual increases of 2%, 4%, and 6%, respectively. Notably, only the F group showed a decline in the annual progression rate over time, suggesting that instrumented posterior fusion may help suppress the progression of OPLL.

Introduction: Proper alignment of the craniovertebral junction (CVJ) is sometimes difficult to determine during surgery. O–C2 angle is a reliable indicator for evaluating flexion–extension of the CVJ. For assessing anterior–posterior translation (APT), the basion-axial interval and clivo-axial angle are commonly used. However, these indicators can be difficult to apply because key landmarks such as the basion and clivus line are not always clearly visible on X-rays. By contrast, the sella turcica is easier to identify because of its distinctive anatomical shape. Its proximity to the CVJ also makes it easy to capture within the field of view on X-ray or fluoroscopy. The authors report new parameters based on this landmark.

Methods: On lateral X-rays of the CVJ and cervical spine, the angle between line SP (connecting the center of the sella turcica [S] and posterosuperior edge of C3 [P]) and the posterior C3 line (pC3L) was defined as the STF/A (sella turcica fore/aft) angle. The perpendicular distance between point S and pC3L was defined as h. The distance h was adjusted relative to the anterior–posterior diameter of the C3 vertebral body.

(Control Group) A total of 67 consecutive patients were enrolled. Inclusion criteria included cases of cervical spondylotic myelopathy and cervical disc herniation. Evaluations were performed before surgery.

(CVJ instability Group) A total of 23 consecutive patients who underwent posterior occipitocervical fusion were enrolled. Evaluations were performed before surgery and 6 months postoperatively. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score for cervical myelopathy, the JOA Cervical Myelopathy Evaluation Questionnaire, and the Visual Analogue Scale.

Results: Radiographic parameters showed no significant differences between the two groups. Measurements in the Control Group indicated that the typical range of the STF/A angle is between 5 and 20 degrees. A significant positive correlation was observed between preoperative and postoperative STF/A angles. In the CVJ Instability Group, 7 cases (30.4%) showed residual APT. Residual posterior translation (3 of 4 cases) was more frequent than residual anterior translation (3 of 7 cases). Clinical outcomes were similar when comparing residual APT (−) group and the residual APT (+) group.

Conclusions: The sella turcica is an easily identifiable landmark, even within a small field of view on X-ray or fluoroscopy. The STF/A angle serves as a useful indicator for adjusting APT of the CVJ during surgery. In cases of posterior translation, conventional indicators may be insufficient to assess alignment, so particular attention is required to prevent residual posterior translation.

Introduction: Various posterior decompression procedures exist for cervical spondylotic myelopathy (CSM), each with advantages and disadvantages. We introduced macroscopic muscle-preserving selective laminectomy (MMSL) and compared its outcomes with the conventional spinous process-splitting laminoplasty (SPSL).

Methods: MMSL uses a 4-5 cm midline incision performed under headlight-guided direct vision, followed by spinous process splitting to expose the paraspinal muscles and allow for a 13 mm laminectomy. We analyzed 219 patients who underwent posterior decompression for CSM at our institution from June 2016 to September 2023 (MMSL: 119 cases; SPSL: 100 cases). Patients with ossification of the posterior longitudinal ligament (OPLL), radiculopathy, or a history of spinal or lower limb orthopedic surgery were excluded. Surgical time, blood loss, radiographic parameters, and clinical outcomes (JOA score, neck VAS, NDI, and JOACMEQ) were compared at one year postoperatively.

Results: There were no significant differences between the two groups in terms of blood loss, complications, JOA recovery rate, neck VAS, NDI, or JOACMEQ. However, the MMSL group had a significantly shorter operative time and better preservation of postoperative cervical lordosis.

Conclusions: MMSL reduces operative time while maintaining clinical outcomes comparable to SPSL. It is a minimally invasive and stable surgical option for posterior decompression in CSM.

Introduction: Spinal metastases in cancer patients can lead to severe pain and paralysis from skeletal-related events (SREs). As the time to SRE onset is relatively short based on previous reports, early detection and prompt treatment are crucial. We developed a medical system where radiologists immediately notify spine surgeons of suspected spinal metastases found on imaging scans (positron emission tomography, computed tomography, magnetic resonance imaging). In addition, spine surgeons evaluate imaging results and refer such cases to cancer treatment doctors. The purpose of this study was to clarify the time delays 1) from diagnosis to orthopedic referral and 2) from referral to treatment initiation. Furthermore, we evaluated the burden to spine surgeons based on the number of spinal metastatic tumor per month.

Methods: We recruited 43 cases identified by this system between October 2021 and December 2023. Of those, 36 cases were referred to our department via cancer treatment doctors. We evaluated time delays of the three treatment methods, such as surgery, radiotherapy and bone modifying agents, for spinal metastatic tumor.

Results: The median time from imaging diagnosis to orthopedic referral was 7 days. The median time from referral to treatment initiation was 21 days, although there were no statistically significant differences in time delays among the three treatment methods. The system generated an average of two referrals per month.

Conclusions: Our system effectively facilitates early detection and referral of spinal metastases, although challenges remain in shortening the time to treatment initiation. We also concluded that the burden on spine surgeons when this system was introduced was not excessive.