Extrusion of the anterior segment of the medial meniscus extrusion initiates knee osteoarthritis: evaluation using magnetic resonance imaging.

PURPOSE: Meniscus extrusion contributes to the progression of knee osteoarthritis (OA). It is not clear which site of the medial meniscus (MM) extrusion (MME) is greatest. Moreover, the relationship between sites of MME and progression of OA has not yet been elucidated. The purpose of this study was to determine which sites of MME that showed the greatest extrusion and to investigate the relationship between the presence of MM tears and MME, the relationship between the progression of OA and MME. METHODS: A cohort of 111 patients were studied retrospectively. The OA grade was classified using the Kellgren-Lawrence (K-L) grade. MME was measured at 13 positions from the anterior to the posterior segment using magnetic resonance imaging (MRI) with slices perpendicular to the MM (radial MRI). The relationship between the K-L grade and the site of the MME was investigated. The patients were grouped as follows: The patients over 40-years-old were grouped as follows: patients with the K-L grade ≤1 and without a MM tear (Group En (early, no meniscus tear)); patients with the K-L grade ≤1 with a MM tear (Group Ep (early, positive meniscus tear)); patients with the K-L grade ≥2 and without a MM tear (Group An (advanced, no meniscal tear)); patients over-40 years-old with the K-L grade ≥2 and with a MM tear (Group Ap (advanced, positive meniscus tear)). And patients between 15 and 39-years-old with no abnormal findings on MRI were defined as control group (Group C). RESULTS: In the Groups En and Ep, MME was greatest in the anterior segment, and was greater in Group Ep than in Group En. In Groups Ap and Group C, extrusion was greatest in the middle segment. CONCLUSION: The results suggest that MME predominantly occurred in the anterior segment with increasing age, after that, MM extruded at the middle segment with progression of OA and MM tear.

Impact of morphological restoration of the spinal cord from the preoperative to early postoperative periods on C5 palsy development.

OBJECTIVE: C5 palsy (C5P) is a known complication of cervical decompression surgery. The tethering effect of the C5 nerve root following the posterior shift of the spinal cord is the most accepted pathologic mechanism for C5P development; however, this mechanism cannot fully explain C5P by itself in clinical practice. Separately, some studies have suggested that preoperative severe spinal cord compression and postoperative morphological changes in the spinal cord affect C5P development; however, no previous study has quantitatively addressed these possibilities. The aim of this study was to examine whether spinal cord morphology and morphological restoration after surgery affect C5P development. METHODS: The authors reviewed consecutive patients with degenerative cervical myelopathy who underwent laminoplasty including the C3-4 and C4-5 intervertebral disc levels. All participants underwent MRI both preoperatively and within 4 weeks postoperatively. To assess the severity of spinal cord compression, the compression ratio (CR; spinal cord sagittal diameter/transverse diameter) was calculated. As an index of morphological changes in the spinal cord during the early postoperative period, the change rate of CR (CrCR, %) was calculated as CRwithin 4 weeks postoperatively/CRpreoperatively × 100. These measurements were performed at both the C3-4 and C4-5 intervertebral disc levels. The study cohort was divided into C5P and non-C5P (NC5P) groups; then, CR and CrCR, in addition to other radiographic variables associated with C5P development, were compared between the groups. RESULTS: A total of 114 patients (mean age 67.6 years, 58.8% men) were included in the study, with 5 and 109 patients in the C5P and NC5P groups, respectively. Preoperative CR at both the C3-4 and C4-5 levels was significantly lower in the C5P group than in the NC5P group (0.35 vs 0.44, p = 0.042 and 0.27 vs 0.39, p = 0.021, respectively). Patients with C5P exhibited significantly higher CrCR at the C3-4 level than those without (139.3% vs 119.0%, p = 0.046), but the same finding was not noted for CrCR at the C4-5 level. There were no significant differences in other variables between the groups. CONCLUSIONS: This study reveals that severe compression of the spinal cord and its greater morphological restoration during the early postoperative period affect C5P development. These findings could support the involvement of segmental cord disorder theory, characterized as the reperfusion phenomenon, in the pathomechanism of C5P, in addition to the tethering effect.

Gas containing intraspinal synovial cyst in the lumbar spine: Case report and literature review.

Intraspinal synovial cyst (ISC) is a well-documented pathology. It is sometimes found in the degenerative lumbar spine and can result in neurological disorders. ISC typically contains xanthochromic fluid, blood, inflammatory tissue, and/or osseous structures, enclosed by fibrous tissue. Regarding the treatment modalities, the effectiveness of both nonsurgical management, such as oral analgesics, needle aspiration, and intra-articular injection of corticosteroid drugs, and surgical management, have been reported. Previous studies have described that the ISC can contain gas, which is derived from the vacuum phenomenon of an adjacent facet joint; however, this clinical condition has never been systematically investigated because of its rarity. In the present report, we describe the case of a 68-year-old male with gas-containing ISC in the lumbar spine who was successfully treated with surgical management; additionally, we performed a literature review to discuss the decision-making process for cases of gas-containing ISC. Based on our findings and previous literature, we recommend that considering the peculiarity of the content of such lesions in addition to the ball-valve effect of a synovial cyst, prompt transition to surgical management would be pertinent when nonsurgical treatment cannot achieve satisfactory outcomes in such cases.

Health-related quality of life, including marital and reproductive status, of middle-aged Japanese women with posterior spinal fusion using Cotrel-Dubousset instrumentation for adolescent idiopathic scoliosis: Longer than 22-year follow-up.

BACKGROUND: Few studies have examined long-term outcomes after posterior spinal fusion using Cotrel-Dubousset instrumentation (CDI) for adolescent idiopathic scoliosis (AIS). Most patients with AIS are female, and their main concern is how spinal fusion will affect their future life. This study aimed to investigate the long-term health-related quality of life (HRQOL), including marital and reproductive status, of middle-aged Japanese women who underwent posterior spinal fusion using CDI for AIS in its earliest days in Japan. METHODS: Japanese women who were younger than 20 years of age at the time of surgery using CDI, between 1985 and 1995, were targeted. Roland-Morris Disability Questionnaire, Oswestry Disability Index, Scoliosis Research Society-22 questionnaire, and 36-Item Short-Form Survey (SF-36) were used to evaluate HRQOL. Marital and reproductive status were also investigated. These results were compared to those of healthy women controls and Japanese national data for 2015. RESULTS: Of 87 female patients, 29 (33.3%) were included, with 71 healthy women as controls. The average age of the patient group was 42.7 years (range 37-48 years), and the average follow-up period was 27.5 years (range 22-32 years). HRQOL scores in the patient group were generally lower than that in the healthy control group, although there was no significant difference between the two groups in the role component summary score (RCS) of SF-36. Marital and reproductive status were not significantly different between patient and control groups, and results for the patient group were similar to Japanese national data. CONCLUSIONS: This is the first study of HRQOL in middle-aged patients who underwent posterior spinal fusion using CDI for AIS in Japan. Although HRQOL scores expect RCS of the patient group were lower than those of the healthy control group, the effects of posterior spinal fusion using CDI on women's social life and marital and reproductive statuses were minimal.

Interbody Bone Graft via Transdiskal Screw Holes as Treatment for High-Grade Spondylolisthesis.

BACKGROUND: Controversy exists regarding surgical treatment of high-grade spondylolisthesis (HGS) in terms of decompression with surgical reduction or in situ fusion. In situ fusion has the advantage of being less technically demanding. However, the residual bone graft area is extremely limited, and posterolateral bone grafting is complex as the transverse process of the slipped vertebrae is located anterior to the sacral ala, which correlates with high rates of pseudoarthrosis. METHODS: Four cases of L5/S1 HGS complaining of low back pain were treated using our new bone graft technique with an exposed osseous end plate. Transdiskal screw holes were made from the S1 pedicle, and bone chips were packed into the L5/S disk space through the screw holes. The slipped L5 vertebra was fixed with a combination of L5/S1 transdiskal and L5 pedicle screws. RESULTS: All cases exhibited good bony fusion, and the low back pain disappeared in all patients up to the 12-month follow-up. This technique involved packing the bone into the closed space, relieving any concerns regarding bone graft migration. CONCLUSIONS: Transpedicular bone graft via transdiskal screw holes is an easy and practical technique for raising the fusion rate in surgical treatment of HGS.

The Evaluation of Indirect Neural Decompression After Lateral Lumbar Interbody Fusion Using Intraoperative Computed Tomography Myelogram.

BACKGROUND: The effect of indirect decompression after lateral lumbar interbody fusion (LLIF) is widely acknowledged; however, its details remain unclear. This study aimed to evaluate the immediate effects of indirect decompression just after LLIF cage placement but just before posterior instrumentation, using intraoperative computed tomography myelogram (iCTM). METHODS: Fifty-three levels from 28 patients undergoing LLIF with iCTM, were included in this retrospective study. Radiographic parameters were obtained from preoperative computed tomography myelogram and iCTM. Segmental correction, cross-sectional areas of the spinal canal, and bilateral foramen were compared preoperatively and intraoperatively to assess the neural decompression just after LLIF cage placement. Canal stenosis status during axial computed tomography myelogram was classified into 3 grades according to modified Schizas's grading to determine the necessity of additional posterior decompression procedures. The Oswestry Disability Index was obtained before and 3 months after the operation. RESULTS: Significant improvements in all radiological parameters of segmental correction, cross-sectional areas of the spinal canal, and bilateral foramen were observed just after LLIF cage placement. However, 11 (21%) levels had insufficient neural decompression status with iCTM grade (10 central canal and 1 lateral recess stenosis), requiring further direct posterior decompression. The difference in the improvement of Oswestry Disability Index between the decompression and nondecompression group was not significant, suggesting the validity of our decision. CONCLUSIONS: Detailed evaluation with iCTM revealed that adequate indirect decompression with LLIF was not always obtained, validating the intraoperative decision of further posterior decompression. This procedure, LLIF with iCTM, may reduce the risk of unnecessary direct decompression and reoperation after insufficient indirect decompression.