Surgery-related predictable risk factors influencing postoperative clinical outcomes for thoracic myelopathy caused by ossification of the posterior longitudinal ligament: a multicenter retrospective study.

OBJECTIVE: Compression of the spinal cord by thoracic ossification of the posterior longitudinal ligament (T-OPLL) often causes severe thoracic myelopathy. Although surgery is the most effective treatment for T-OPLL, problems associated with surgical intervention require resolution because surgical outcomes are not always favorable, and a small number of patients experience deterioration of their neurological status after surgery. The aim of the present study was to examine the surgery-related risk factors contributing to poor clinical outcomes for myelopathy caused by T-OPLL. METHODS: Data were extracted from the records of 55 patients with thoracic myelopathy due to T-OPLL at institutions in the Fukuoka Spine Group. The mean follow-up period was 5.3 years. Surgical outcomes were assessed using the Japanese Orthopaedic Association (JOA) scale. To investigate the definitive factors associated with surgical outcomes, univariate and multivariate regression analyses were performed with several patient-related and surgery-related factors, including preoperative comorbidities, radiological findings, JOA score, surgical methods, surgical outcomes, and complications. RESULTS: Neurological status improved in 33 patients (60.0%) and deteriorated in 10 patients (18.2%) after surgery. The use of instrumentation was significantly associated with an improved outcome. In the comparison of surgical approaches, posterior decompression and fusion resulted in a significantly higher neurological recovery rate than did anterior decompression via a posterior approach and fusion or decompression alone. It was also found that postoperative neurological status was significantly poorer when there were fewer instrumented spinal levels than decompression levels. CSF leakage was a predictable risk factor for deterioration following surgery. CONCLUSIONS: It is important to identify preventable risk factors for poor surgical outcomes for T-OPLL. The findings of the present study suggest that intraoperative CSF leakage and a lower number of instrumented spinal fusion levels than decompression levels were exacerbating factors for the neurological improvement in T-OPLL surgery.

Quantitative analysis of indirect decompression in extreme lateral interbody fusion and posterior spinal fusion with a percutaneous pedicle screw system for lumbar spinal stenosis.

BACKGROUND: The authors sought to quantify the results of clinical and radiological analyses of extreme lateral interbody fusion (XLIF) plus percutaneous pedicle screw (PPS) fixation for patients with lumbar spinal stenosis (LSS) by focusing on the distinct mechanism of indirect decompression. METHODS: Data obtained from a total of 37 patients with 47 surgical sites were retrospectively analyzed. Clinical outcomes for all patients were evaluated using the Japanese Orthopaedic Association (JOA) score and the improvement rate of the JOA score. Preoperative and postoperative magnetic resonance images were used to measure the transverse areas of both the dural sac (DS area) and ligamentous flavum (LF area) in the axial sections and the length of the intervertebral disc bulge (DB length) in sagittal sections. Then, the rate of change (RC) of the DS area (RC-DS), the RC of the LF area (RC-LF), and the RC of the DB length (RC-DB) from the preoperative period to the postoperative period were calculated. Furthermore, we divided all surgical sites into the small expansion group (SE group; RC-DS <150%) and large expansion group (LE group; RC-DS ≥200%) according to the degree of RC-DS. RESULTS: Preoperative clinical symptoms improved significantly after surgery for all patients regardless of whether the RC-DS was large or small. RC-DS, RC-LF, and RC-DB were approximately 203%, 74%, and 37%, respectively. Moreover, we found that the bulging was significantly shorter in the LE group than in the SE group, although there was no difference in the RC-LF between the LE group and SE group. CONCLUSIONS: We suggest that indirect decompression after XLIF is particularly influenced by the degree of reduction in DB.

Clinical and imaging features of a subchondral insufficiency fracture of the femoral head after internal fixation of a femoral neck fracture: a comparison with those of post-traumatic osteonecrosis of the femoral head.

OBJECTIVE: Recent articles have demonstrated that subchondral insufficiency fractures (SIFs) of the femoral head can occur following internal fixation of femoral neck fractures (FNFs), in addition to post-traumatic osteonecrosis (ON) of the femoral head. The purpose of this study was to determine the clinical and imaging features of SIF after internal fixation of FNFs compared with those of post-traumatic ON. METHODS: We reviewed five hips in five patients, who received internal fixation for the treatment of FNF and were diagnosed as having SIF according to the shape of the low-intensity band on the T1 weighted MR image. Four hips of four patients with post-traumatic ON were compared with the SIF cases. Both the clinical and imaging findings were investigated. RESULTS: There were no significant differences in the age, sex, body mass index, stage of FNF or duration from injury to surgery between SIF and post-traumatic ON. Regarding the prognosis, one of the five cases (20%) with SIF underwent prosthetic replacement owing to a progressive collapse of the femoral head. Two of the four cases (50%) with post-traumatic ON underwent prosthetic replacement. CONCLUSION: The results of this study suggest that SIF should be considered a possible condition following the internal fixation of FNFs, and it is important to differentiate SIF from post-traumatic ON. ADVANCES IN KNOWLEDGE: SIF should be considered a possible condition following the internal fixation of FNFs.

Direct reduction may need to be considered to avoid postoperative subtype P in patients with an unstable trochanteric fracture: a retrospective study using a multivariate analysis.

INTRODUCTION: It has recently been reported that the cases with an anterior femoral neck cortex posterior to the distal fragment (subtype P) in the lateral view of a postoperative radiograph have a risk of excessive sliding of lag screws compared to those located anterior to the distal fragment (subtype A) or perfectly continuous to the distal fragment (subtype N) following osteosynthesis for the treatment of a trochanteric fracture. The purpose of this study was to investigate factors that influence the postoperative subtype in the lateral view of radiographs. PATIENTS AND METHODS: This study reviewed 136 patients who underwent osteosynthesis using an intramedullary hip nail for the treatment of a trochanteric fracture. A closed reduction was performed in 130 patients (95.6 %), while a direct reduction via a small elevator with a small skin incision was performed in the other six patients (4.4 %). The 136 patients were divided into two groups (subtype P and subtype A or N) based on postoperative radiographs taken of the lateral view. Both clinical and radiological factors were analyzed using the univariate and multivariable analyses. RESULTS: Thirty-nine patients (29 %) were categorized as subtype P and 97 patients (71 %) were categorized as subtype A or N. A multivariate analysis demonstrated that unstable fractures were associated with a significant risk of postoperative subtype P (Odds ratio: 24.45, P = 0.0024). CONCLUSIONS: The results of this study suggest that direct reduction via a small elevator with a small skin incision or percutaneous intrafocal pinning may be needed in these cases.

Three-dimensional analyses of proximal humeral fractures using computed tomography with multiplanar reconstruction: early stability of fixation after osteosynthesis in relation to preoperative bone quality.

The purpose of this study was to evaluate the relationship between the bone quality of the humeral head measured by CT multiplanar reconstruction images (MPR) and the stability of nail or plate fixation and to compare the clinical outcomes of these procedures in patients with proximal humeral fractures. Thirty-six consecutive patients (nail group: n = 18, plate group: n = 18) were investigated. In nail group, 14 cases were classified as two-part fractures, three cases were classified as three-part fractures and one case was classified as four-part fractures. In plate group, three cases were classified as two-part fractures, nine cases were classified as three-part fractures and six cases were classified as four-part fractures. Both clinical and radiological outcomes were assessed. In addition, the percentage of trabecular bone volume of the humeral head was calculated using preoperative CT-MPR images. Three patients in the nail group underwent reoperation. In contrast, no patients in the plate group underwent reoperation. In nail group, six of 18 (33%) patients demonstrated poor results (three underwent reoperation, and three had varus displacements >10º) and had bone volume percentages (axial image) that were significantly lower than those observed in the patients with good results. The cutoff point of trabecular bone volume required to obtain satisfactory results after surgical treatment using intramedullary nail was 78%. The results of this study suggest that the bone volume of the humeral head calculated using CT-MPR images provides useful information, in addition to the type of fracture, when selecting fixation devices for osteosynthesis of proximal humeral fracture.

Validation study of a clinical diagnosis support tool for lumbar spinal stenosis.

BACKGROUND: A clinical diagnosis support tool for lumbar spinal stenosis was developed by the Japanese Society for Spine Surgery and Related Research. However, the use of this tool has not yet been validated. METHODS: Patients with symptoms in the lower extremities and who visited the Department of Orthopedics initially were recruited to the study. Orthopedic physicians who were not spine specialists completed the support tools. Spine specialists examined the patients, made a diagnosis, and completed the lumbar spine examination sheet made for the study. The support tool and lumbar spine examination sheet were sent to a central panel comprising four panelists who then decided on a final diagnosis. RESULTS: In total, 118 patients were evaluated, including 62 males and 56 females. Lumbar spinal stenosis was diagnosed in 58 and nonlumbar spinal stenosis in 60 patients. The mean score in the lumbar spinal stenosis group was 12.2 points (median 13 points). In the nonlumbar spinal stenosis group, the mean score was 7.5 points (median 7 points). Sensitivity was 0.948, and specificity was 0.40. CONCLUSIONS: Patients with lumbar spinal stenosis with a very low score were diagnosed with mild lumbar spinal stenosis, whereas nonlumbar spinal stenosis patients with a very high score were diagnosed as suffering from spine disease and needing special treatment by spine surgeons. Our results validate the use of the support tool for the diagnosis of lumbar spinal stenosis. Although the specificity observed in the present study was lower than that reported at development, we conclude that this support tool is useful for screening patients with lumbar spinal stenosis.