Introduction: Primary sacral tumors are rare lesions and their oncological prognosis is poor. Sacral neuroanatomy increases difficulties in neurological function in patients with sacral tumors. Our study presents the results of a group of patients with primary sacral tumors who were treated by the same multidisciplinary team at our institution.

Methods: Between 2013 and 2020,15 patients with primary sacral tumors (10 men and 5 women) were treated. The diagnosis included chordoma in four patients, Ewing's sarcoma and plasma cell tumor in two patients each, and osteosarcoma, chondrosarcoma, fibrosarcoma, malignant peripheral nerve sheath tumor, malignant germ cell tumor, osteoid osteoma, and giant cell tumor in one patient each. The lesion site of each tumor was classified into 1 of 4 types. Type 1 had their upper extent at S3, type 2 had their upper extent at S2, type 3 had their upper extent at S1, and type 4 extended to the iliac bone. We evaluated the outcome in terms of local disease control and residual neurological dysfunction.

Results: All cases of chordoma were administered with irradiation including carbon-ion radiotherapy, and case of type 4 giant cell tumor was administered denosumab. Local recurrence occurred and bladder dysfunction appeared in one case of chordoma. The other cases did not present neurological dysfunction; all patients lived despite the disease. Four cases of malignant tumors were classified as type 3 or 4 and were administered chemotherapy and irradiation without surgery. All these cases presented loss of bladder and bowel control; all patients died due to the disease. Two cases of Ewing's sarcoma and one case of malignant germ cell tumor were classified as type 1 or 2 and underwent partial sacrectomy after preoperative chemotherapy. Partial sacrectomy was performed at the S2-3 level via bilateral S-2 and unilateral S-3 nerve preservation. Local recurrence occurred and the patient died due to the disease in one of Ewing's sarcoma. The remaining two cases were continuously disease free and showed no worsening of neurological function.

Conclusions: Radiotherapy and denosumab treatment were useful in obtaining sufficient local control of sacral tumors depending on the histopathology. Partial sacrectomy with preservation of the unilateral S-3 nerve may prove beneficial in providing certainty of retaining neurological function such as bladder and bowel control. This surgery should be considered for lower origin malignant sacral tumors if the extent resection is allowed.

Introduction: Clinical results of posterior decompression surgery for lumbar spinal canal stenosis with Modic change Type1 were examined.

Methods: Subjects included 122 cases of lumbar spinal canal stenosis that underwent spinous process-splitting laminectomy. Seventy-eight cases were men and 44 were women, with an average age of 72 years and a follow-up period of approximately 303 days. Subjects were compared by dividing them into two groups, group M of 29 and group NM of 93 cases, with and without Modic change Type1.

Results: Average improvement ratio of JOA score and VAS variation of lower back and lower leg pain as well as lower leg numbness observed in group M and NM were 55.6% and 58.2%, 14.0 mm and 22.5 mm, 18.0 mm and 35.8 mm, and 22.3 mm and 30.9 mm, respectively. Scores of group M and NM obtained in JOABPEQ regarding disorders relating to pain, functional disorder caused due to back pain, locomotor function disorder, social life disorder, and psychological disorder were 26.1 and 22.4 points, 9.4 and 11.8 points, 21.1 and 22.6 points, 16.6 and 17.7 points, and 9.0 and 7.8 points, respectively.

Conclusions: Even with Modic change Type1, low back pain, lower limb pain and lower limb numbness may still persist; however, other clinical results were not influenced in posterior decompression for lumbar spinal canal stenosis.

Introduction: Impacts of sacroiliac joint degeneration were examined on clinical results of posterior decompression for lumbar spinal canal stenosis.

Methods: A total of 107 cases of lumbar spinal canal stenosis were analyzed, wherein 67 and 41 cases were men and women, respectively, with an average age of 72 years. The follow-up period was 315 days on average. Subjects were compared via dividing into group N of 67 and D of 40 cases with type 0, 1 and type 2, 3 by Eno classification about sacroiliac joint degeneration.

Results: Average recovery rate of JOA score and VAS variation of low back and lower leg pain along with lower leg numbness observed in group N and D were 56.5% and 58.9%, 14.2 and 30.9 mm, 27.9 and 39.0 mm, and 30.3 and 28.1 mm, respectively. Scores of group N and D obtained in JOABPEQ regarding disorders relating to pain, function disorder caused by back pain, locomotor function disorder, social life disorder, and psychological disorder were 19.2 and 31.4 points, 9.4 and 17.0 points, 21.8 and 26.4 points, 16.1 and 20.9 points, and 8.0 and 8.5 points, respectively. The amount of change of low back pain VAS was significantly different between the two groups.

Conclusions: The amount of change of low back pain VAS was significantly larger in patient with more severe sacroiliac joint degeneration in the outcomes of posterior decompression for lumbar spinal stenosis.

Introduction: This study aimed to investigate the association between the Oswestry Disability Index (ODI) and The Fear of COVID-19 Scale (FCV-19S) scores in postoperative patients with lumbar spine disease.

Methods: Patients who underwent surgery for lumbar degenerative disease were included. The following items were evaluated at the outpatient examination: age, gender, body mass index, postoperative days, surgical formula (fusion, laminectomy), arthrodesis level, state of emergency, mental health, sensory impairment, Functional Reach Test (FRT), 30-Second Chair Stand Test, low back pain, leg pain, FCV-19S, SVA, LL, PI, PT, TK, SS. In the statistical analysis, multivariate analysis was performed (P < 0.05).

Results: In the multivariate analysis, statistical significance was found in these variables in the following order: FRT (p < 0.001, β = −0.45), low back pain (p = 0.005, β = 0.28), FCV-19S (p = 0.004, β = 0.28) (contribution rate 45%).

Conclusions: FCV-19S was found to be associated with ODI in postoperative patients with lumbar degenerative disease.

Introduction: The S2 alar iliac screw (S2AIS) is used in the corrective surgery of adult spinal deformities. It provides biomechanical support and acts as a strong caudal anchor; however, it passes through the sacroiliac joint, which has a range of motion, and its effect on the joint is unclear. The sacroiliac joint has rotational movements; therefore, it is difficult to stabilize by just one screw and S2AIS loosening might be inevitable. In this study, we investigated the effect of S2AIS loosening on the sacroiliac joint.

Methods: This retrospective study included 38 patients who underwent corrective surgery from the thorax to the sacrum for adult spinal deformity and at least 2 years of follow-up. S2AIS loosening was assessed via the radiolucent zone of computed tomography. The patients were divided into two groups (loosening and nonloosening groups), and the two groups were compared in terms of the sagittal parameters of standing radiographs, SRS-22, arthritic change, and pain in the sacroiliac joint.

Results: S2AIS loosening was observed in 32 (42%) patients. There was no significant difference between the two groups in terms of full spine standing radiographs and SRS-22. Arthritic change was observed in five joints (11%) in the nonloosening group and five joints (6%) in the loosening group. Sacroiliac joint pain was observed in 5 joints (11%) in the nonloosening group and 4 joints (13%) in the loosening group.

Conclusions: Loosening of the S2AIS occurred in 42% of the patients. There was no difference between the two groups in terms of the occurrence of arthritic changes or joint pain in the sacroiliac joint. Loosening of the S2AIS does not cause arthritic changes and joint pain in the sacroiliac joint for a minimum of 2 years after adult spinal deformity corrective surgery.

Introduction: In rare cases, leg pain may occur due to compression lesions in the cervical cord and thoracic spinal cord, which is called a "false localizing sign." Leg pain is rare, but foot drop is very rare. We report two cases of foot drop due to an upper thoracic compression lesion.

Case Report: Case 1: A 72-year-old man was diagnosed with a right foot drop due to compression of the thoracic spinal cord. Decompression and fixation were performed, and postoperative foot drop improved. Case 2: A 42-year-old woman underwent tumor resection for the left foot drop due to meningioma at the first thoracic spinal level, and the left foot drop recovered after surgery.

Conclusions: The common points of our examples are (1) lack of lumbar and thoracolumbar transitional lesions that can explain the foot drop, (2) Iliopsoas muscle weakness, (3) high back pain, and (4) strong compression findings on the outside of the spinal cord on the image. The cervical-thoracic spine junction is where mobility and curvature change and collateral circulation is poor. This anatomical feature may have manifested itself as a false localizing sign. Foot drop may be present due to an upper thoracic compression lesion. Therefore, the possibility of spinal cord lesions should be considered when the foot drop with poor lumbar imaging findings is observed.