The Japanese Orthopaedic Association (JOA) score is widely used to assess the severity of clinical symptoms in patients with cervical compressive myelopathy, particularly in East Asian countries. In contrast, modified versions of the JOA score are currently accepted as the standard tool for assessment in Western countries. The objective of the present study is to compare these scales and clarify their differences and interchangeability and verify their validity by comparing them to other outcome measures. Five institutions participated in this prospective multicenter observational study. The JOA and modified JOA (mJOA) proposed by Benzel were recorded preoperatively and at three months postoperatively in patients with cervical compressive myelopathy who underwent decompression surgery. Patient reported outcome (PRO) measures, including Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), the Short Form-12 (SF-12) and the Neck Disability Index (NDI), were also recorded. The preoperative JOA score and mJOA score were compared to each other and the PRO values. A Bland-Altman analysis was performed to investigate their limits of agreement. A total of ninety-two patients were included. The correlation coefficient (Spearman’s rho) between the JOA and mJOA was 0.87. In contrast, the correlations between JOA/mJOA and the other PRO values were moderate (|rho| = 0.03 – 0.51). The correlation coefficient of the recovery rate between the JOA and mJOA was 0.75. The Bland-Altman analyses showed that limits of agreement were 3.6 to -1.2 for the total score, and 55.1% to -68.8% for the recovery rates. In the present study, the JOA score and the mJOA score showed good correlation with each other in terms of their total scores and recovery rates. Previous studies using the JOA can be interpreted based on the mJOA; however it is not ideal to use them interchangeably. The validity of both scores was demonstrated by comparing these values to the PRO values.

A retrospective case-control study. To determine factors influencing the ability to achieve coronal balance following spinal deformity surgery. Following institutional ethics approval, the radiographs of 47 patients treated for spinal deformity surgery with long fusions to the pelvis, were retrospectively reviewed. The postoperative measurements included coronal balance, L4 tilt, and L5 tilt, levels fused, apical vertebral translation and maximum Cobb angle. L4 and L5 tilt angles were measured between the superior endplate and the horizontal. Sagittal parameters including thoracic kyphosis, lumbar lordosis, pelvic incidence, and sagittal vertical axis were recorded. Coronal balance was defined as the distance between the central sacral line and the mid body of C7 being ≤40 mm. Surgical factors, including levels fused, use of iliac fixation with and without connectors, use of S2A1 screws, interbody devices, and osteotomies. Statistical tests were performed to determine factors that contribute to postoperative coronal imbalance. Of the 47 patients reviewed, 32 were balanced after surgery and 14 were imbalanced. Coronal balance was 1.30 cm from center in the balanced group compared to 4.83 cm in the imbalanced group (P < .01). Both L4 and L5 tilt were statistically different between the groups. Gender and the use of transverse connectors differed between the groups but not statistically. In adult spinal deformity patients undergoing primary fusions to the pelvis, the ability to level the coronal tilt of L4 and L5 had the greatest impact on the ability to achieve coronal balance in this small series. A larger prospective series can help validate this important finding.

Study Design. A retrospective study. Objective. To investigate the relationship between intraoperative blood loss during spinal metastasis surgery and the surgical delay after preoperative embolization. Summary of Background Data. Delaying surgery after embolization is thought to diminish its effectiveness because of revascularization, but there has been no scientific study that supports this hypothesis. Methods. We reviewed data from 66 consecutive posterior palliative decompression surgical procedures for spinal metastasis from thyroid and renal cell carcinoma (39 thyroid and 27 renal) in 58 patients between 2004 and 2012. All patients underwent preoperative angiography. The timing of preoperative embolization was determined on the basis of the operating room and interventional radiologist schedules. Excluding one case who did not receive embolization due to lack of hypervascularity, we analyzed 65 cases to compare intraoperative blood loss according to the completeness of embolization and the time lapse between embolization and surgery. Results. Surgical procedures were performed on the same day of embolization in 21 cases (same day-group), and on the next day after embolization in 39 cases (next-day group). Five surgical procedures were performed 2 days later. The intraoperative blood loss was significantly lesser with complete embolization than with partial embolization (mean ± standard deviation: 809 ± 835 vs. 1210 ± 904 mL, P = 0.03). Among those with complete embolization, the intraoperative blood loss as well as the perioperative transfusion requirement was significantly lesser in the same-day group than in the next-day group (mean ± standard deviation: blood loss: 433 ± 376 vs. 1012 ± 974 mL, P = 0.01; transfusion requirement: 1.5 ± 1.7 vs. 4.2 ± 4.1 units, P = 0.04). Conclusion. Preoperative embolization showed greater effectiveness in reducing intraoperative blood loss when surgery for spinal metastasis was performed on the same day than when surgery was delayed. Surgery should be performed on the same day of embolization if possible. Level of Evidence: 4

Ectopic endochondral ossification in the tendon/ligament is caused by repetitive mechanical overload or inflammation. Tendon stem/progenitor cells (TSPCs) contribute to tissue repair, and some express lubricin [proteoglycan 4 (PRG4)]. However, the mechanisms of ectopic ossification and association of TSPCs are not yet known. Here, we investigated the characteristics of Prg4-positive ( ⁺ ) cells and identified that R-spondin 2 (RSPO2), a WNT activator, is specifically expressed in a distinct Prg4 ⁺ TSPC cluster. The Rspo2 ⁺ cluster was characterized as mostly undifferentiated, and RSPO2 overexpression suppressed ectopic ossification in a mouse Achilles tendon puncture model via chondrogenic differentiation suppression. RSPO2 expression levels in patients with ossification of the posterior longitudinal ligament were lower than those in spondylosis patients, and RSPO2 protein suppressed chondrogenic differentiation of human ligament cells. RSPO2 was induced by inflammatory stimulation and mechanical loading via nuclear factor κB. Rspo2 ⁺ cells may contribute to tendon/ligament homeostasis under pathogenic conditions.