Surgical Intervention for Osteoporotic Vertebral Burst Fractures in Middle-low Lumbar Spine with Special Reference to Postoperative Complications Affecting Surgical Outcomes.

The purpose of this study was to investigate the clinical and radiological features of osteoporotic burst fractures affecting levels below the second lumbar (middle-low lumbar) vertebrae, and to clarify the appropriate surgical procedure to avoid postoperative complications. Thirty-eight consecutive patients (nine male, 29 female; mean age: 74.8 years; range: 60-86 years) with burst fractures affecting the middle-low lumbar vertebrae who underwent posterior-instrumented fusion were included. Using the Magerl classification system, these fractures were classified into three types: 16 patients with superior incomplete burst fracture (superior-type), 11 patients with inferior incomplete burst fracture (inferior-type) and 11 patients with complete burst fracture (complete-type). The clinical features were investigated for each type, and postoperative complications such as postoperative vertebral collapse (PVC) and instrumentation failure were assessed after a mean follow-up period of 3.1 years (range: 1-8.1 years). All patients suffered from severe leg pain by radiculopathy, except one with superior-type fracture who exhibited cauda equina syndrome. Nineteen of 27 patients with superior- or inferior-type fracture were found to have spondylolisthesis due to segmental instability. Although postoperative neurological status improved significantly, lumbar lordosis and segmental lordosis at the fused level deteriorated from the postoperative period to the final follow-up due to postoperative complications caused mainly by PVC (29%) and instrument failure (37%). Posterior-instrumented fusion led to a good clinical outcome; however, a higher incidence of postoperative complications due to bone fragility was inevitable. Therefore, short-segment instrument and fusion with some augumentation techniqus, together with strong osteoporotic medications may be required to avoid such complications.

Minodronate treatment improves low bone mass and reduces progressive thoracic scoliosis in a mouse model of adolescent idiopathic scoliosis.

Recent studies have shown an association between osteopenia and adolescent idiopathic scoliosis (AIS) and implied that osteopenia plays a causative role in AIS development. This study aimed to determine if minodronate (MIN) treatment could prevent curve progression by increasing bone mass in a thoracic restraint (TR) mouse model, which develops causes the development of thoracic scoliosis similar to human AIS. A total of 100 young female C57BL6J mice were divided into four groups: (1) control with vehicle (CON/VEH; n = 20), (2) control with MIN (CON/MIN; n = 20), (3) TR with vehicle (TR/VEH; n = 30), or (4) TR with MIN (TR/MIN; n = 30). MIN (0.01 mg/kg/week) and vehicle were administered intraperitoneally to their respective groups. TR was performed at age 4 weeks, and the mice were sacrificed at age 9 weeks. Body weights, spine radiographs, femoral bone mineral density (BMD), serum bone marker levels, and histomorphometry of the cancellous bone of the thoracic vertebrae were analyzed. TR significantly reduced weight gain in the TR/VEH group relative to the CON/VEH group. TR also induced osteoporosis with accelerated bone resorption, as indicated by decreases in femoral BMDs and thoracic cancellous bone volume and increases in serum bone resorption marker levels and histomorphometric resorption parameters in the TR/VEH group. MIN partially improved body weight gain and improved poor bone structure relative to the TR/VEH group by suppressing high bone resorption in the TR/MIN mice. MIN significantly reduced the curve magnitudes, as indicated by a 43% lower curve magnitude in the TR/MIN mice than in the TR/VEH mice (17.9 ± 8.9° vs. 31.5 ± 13.1°; p< 0.001). The administration of MIN increased bone mass and reduced the severity of scoliosis in the TR mice. MIN was suggested as a possible inhibitor of scoliosis development.

Evaluation of functional and structural leg length discrepancy in patients with adolescent idiopathic scoliosis using the EOS imaging system: a prospective comparative study.

BACKGROUND: To our knowledge, no studies have reported the exact structural leg length discrepancies (LLDs) in patients with adolescent idiopathic scoliosis (AIS). Therefore, this study aimed to evaluate the differences between functional and structural LLDs and to examine the correlations between LLDs and spinopelvic parameters in patients with AIS using an EOS imaging system, which permits the three-dimensional reconstruction of spinal and lower-limb bony structures. METHODS: Eighty-two consecutive patients with AIS underwent whole-body EOS radiography in a standing position between August 2014 and March 2016. Functional LLD, lumbar Cobb angle, thoracic curve Cobb angle, coronal balance, and pelvic obliquity were measured using two-dimensional EOS radiography. Structural LLDs were measured using three-dimensional EOS-reconstructed images. The comparison between LLDs was assessed using paired t test. Pearson's correlation coefficient (r) was used to determine potential correlations between the LLDs and spinopelvic alignment parameters. RESULTS: Functional LLDs were significantly larger than structural LLDs (5.6 ± 5.0 vs. 0.2 ± 3.6 mm, respectively; p < 0.001). Both functional and structural LLDs were significantly correlated with pelvic obliquity (r = 0.69 and r = 0.51, respectively; p < 0.001 for both). Functional LLD, but not structural LLD, was correlated with lumbar Cobb angle (r = 0.44, p < 0.001; r = 0.17, p = 0.12, respectively). In addition, functional and structural LLDs were not correlated with thoracic Cobb angle (r = 0.09 and r = - 0.05, respectively; p ≥ 0.68 for both). CONCLUSIONS: Although patients with AIS often have functional LLDs, structural LLDs tend to be smaller. The correlation between functional LLDs and the lumbar Cobb angle indicates that functional LLDs compensate for the lumbar curve. Thus, the difference between functional and structural LLDs indicates a compensatory mechanism involving extension and flexion of the lower limbs.

A Focal Cooling Method for the Cervical Spinal Cord: A Percutaneous Approach to the Dorsal Neck in Dogs.

For the treatment of acute cervical spinal cord injuries, a local epidural cooling system using a percutaneous technique was proposed. In this animal study, regional low temperature was obtained stably in the cervical epidural space (CED) without decreasing temperatures at the rectum and the thoracic epidural space. Three stainless steel tubes were inserted percutaneously using the lateral approach into 3 serial interspinous spaces of the neck of 12 beagles under radiographic guidance. Two temperature probes were inserted into the CEDs at the level of the middle cooling tube. A third temperature probe was inserted into the epidural space at the Th13 level. A fourth temperature probe was placed in the rectum as a control. Iced water was circulated in the cooling tubes for 60 minutes. Temperatures were monitored every 10 seconds for 90 minutes, with the minimum temperatures during the period being recorded. The mean minimum temperatures recorded in the dorsal CED (min-CED-dorsal), the lateral CED (min-CED-lateral), the Th13 epidural space (min-T13ED), and the rectum (min-rectum), were 16.0 ± 0.6°C, 22.6 ± 1.6°C, 35.4 ± 0.2°C, and 35.5 ± 0.2°C, respectively. There was a statistically significant difference between the mean min-CED-dorsal and min-rectum temperatures (p < 0.0001). The method introduced above was effective in reducing cervical epidural temperature selectively.

Optimal trajectory and insertion accuracy of sacral alar iliac screws.

OBJECTIVE: The aim of this study was to analyse the optimal trajectories for sacral alar iliac screws (SAISs) in a Japanese patient population and the clinical assessment of insertion accuracies. METHODS: The ideal trajectories of SAISs, starting from 2 mm medial to the apex of the lateral sacral crest on the midline between S1 and S2 dorsal foramina, were measured in 80 consecutive spinal disease patients (40 males and 40 females; average age: 67.4 ± 8.1 years) using three-dimensional computed tomographic image software. Following these anatomic analyses, accuracies of 32 inserted SAISs in consecutive patients, who underwent long spinal posterior fusion, were investigated clinically. RESULTS: Lateral angulations of optimal SAIS trajectories in males (left: 37.9; right: 37.7) were significantly larger than those than in females (left: 32.8; right: 32.4). Caudal SAIS angulations for females (left: 33.4; right: 33.9) were significantly larger than those in males (left: 27.5; right: 28.0). The 32 SAISs (100 mm long and 9 mm in diameter) assessed clinically were accurately inserted on optimal trajectories. CONCLUSION: The optimal trajectories of SAISs in a Japanese patient population are more lateral in males and more caudal in females. This study examines the clinical safety and accuracy of SAIS insertion on these optimal trajectories.

Validation study of arm positions for evaluation of global spinal balance in EOS imaging.

BACKGROUND: The sagittal vertical axis (SVA) is important in the evaluation of spinal sagittal balance. Although the "fists-on-clavicles" (FOC) position has been widely used in radiographic examinations, it does not define shoulder flexion in detail. Meanwhile, in EOS imaging, the "hands-on-cheeks" (HOC) position is widely used but has not been well investigated. The purpose of this study was to investigate the relative usefulness of FOC and HOC in investigating SVA. MATERIALS AND METHODS: Mean SVA was measured by EOS imaging using standing lateral radiographs of 34 volunteers in four different positions: relaxed (RLX), shoulder flexion at 90° with FOC (FOC90), elbows touching the trunk with FOC (FOCET), and HOC. RESULTS: The mean SVA was 2.0 ± 2.1 cm in RLX; -1.4 ± 3.2 cm in FOC90; -0.5 ± 3.0 cm in FOCET; and -0.2 ± 2.9 cm in HOC. The negative shift from RLX was significantly greater in FOC90 than in FOCET (-3.4 ± 2.2 vs -2.5 ± 2.4 cm; p = 0.0182). The negative shift from RLX in HOC was almost equal to that in FOCET; the difference was 0.3 cm (-2.2 ± 2.2 vs -2.5 ± 2.4 cm; p = 0.2560). CONCLUSION: FOC90 showed a negative SVA shift in comparison with FOCET. The difference in the mean SVA between HOC and FOCET was 0.3 cm, a clinically small difference.

Retraction Note: Relationship between bone density and bone metabolism in adolescent idiopathic scoliosis.

[This retracts the article DOI: 10.1186/s13013-015-0043-x.].

Relationship between bone density and bone metabolism in adolescent idiopathic scoliosis.

Several authors have confirmed that 27 to 38 % of AIS patients had osteopenia. But few studies have assessed bone metabolism in AIS. This study assessed bone mineral density and bone metabolism in AIS patients using the bone metabolism markers, BAP and TRAP5b. The subjects were 49 consecutive adolescent AIS patients seen at our institutes between March 2012 and September 2013. Sixty-five percent of AIS patients had osteopenia or osteoporosis and 59 % of AIS patients had high values for TRAP5b. The AIS patients with high values of TRAP5b had lower Z scores than those with normal values of TRAP5b. Higher rates of bone resorption are associated with low bone density in AIS patients.

Relationship between bone density and bone metabolism in adolescent idiopathic scoliosis.

Several authors have confirmed that 27 to 38% of AIS patients had osteopenia. But few studies have assessed bone metabolism in AIS. This study assessed bone mineral density and bone metabolism in AIS patients using the bone metabolism markers, BAP and TRAP5b. The subjects were 49 consecutive adolescent AIS patients seen at our institutes between March 2012 and September 2013. Sixty-five percent of AIS patients had osteopenia or osteoporosis and 59% of AIS patients had high values for TRAP5b. The AIS patients with high values of TRAP5b had lower Z scores than those with normal values of TRAP5b. Higher rates of bone resorption are associated with low bone density in AIS patients.

Prospective study of superior cluneal nerve disorder as a potential cause of low back pain and leg symptoms.

BACKGROUND: Entrapment of the superior cluneal nerve (SCN) in an osteofibrous tunnel has been reported as a cause of low back pain (LBP). However, there are few reports on the prevalence of SCN disorder and there are several reports only on favorable outcomes of treatment of SCN disorder on LBP. The purposes of this prospective study were to investigate the prevalence of SCN disorder and to characterize clinical manifestations of this clinical entity. METHODS: A total of 834 patients suffering from LBP and/or leg symptoms were enrolled in this study. Diagnostic criteria for suspected SCN disorder were that the maximally tender point was on the posterior iliac crest 70 mm from the midline and that palpation of the tender point reproduced the chief complaint. When patients met both criteria, a nerve block injection was performed. At the initial evaluation, LBP and leg symptoms were assessed by visual analog scale (VAS) score. At 15 min and 1 week after the injection, VAS pain levels were recorded. If insufficient pain decrease or recurrence of pain was observed, injections were repeated weekly up to three times. Surgery was done under microscopy. Operative findings of the SCN and outcomes were recorded. RESULTS: Of the 834 patients, 113 (14%) met the criteria and were given nerve block injections. Of these, 54 (49%) had leg symptoms. Before injection, the mean VAS score was 68.6 ± 19.2 mm. At 1 week after injection, the mean VAS score significantly decreased to 45.2 ± 28.8 mm (p < 0.05). Ninety-six of the 113 patients (85%) experienced more than a 20 mm decrease of the VAS score following three injections and 77 patients (68%) experienced more than a 50% decrease in the VAS score. Surgery was performed in 19 patients who had intractable symptoms. Complete and almost complete relief of leg symptoms were obtained in five of these surgical patients. CONCLUSIONS: SCN disorder is not a rare clinical entity and should be considered as a cause of chronic LBP or leg pain. Approximately 50% of SCN disorder patients had leg symptoms.

Clinical results of intrapedicular partial pediculectomy for lumbar foraminal stenosis.

DESIGN: A retrospective case study of the use of intrapedicular partial pediculectomy (IPPP) to treat lumbar foraminal stenosis. OBJECTIVE: To evaluate the clinical results of lumbar foraminal stenosis treated with IPPP. SUMMARY OF BACKGROUND DATA: There is no gold standard for the surgical treatment of foraminal stenosis, which occurs in 8% of surgical cases of lumbar degenerative diseases. METHODS: A total of 26 patients who were followed up for a minimum of 2 years after IPPP for foraminal stenosis, were included in this study. The study group consisted of 20 men and 6 women with an average age at surgery of 63.3 years (range: 42 to 83) and a mean follow-up of 5.5 years (range: 2 to 11). The affected levels were L3/4 in 1 patient, L4/5 in 7, and L5/S1 in 18. Bilateral IPPP at L5/S1 was performed in 2 patients. The clinical results were evaluated according to the Japanese Orthopedic Association (JOA) scoring system. RESULTS: Two patients required revision surgery to correct insufficient decompression. In the remaining 24 patients, the average JOA scores were 6.7 (range: -1 to 10) before surgery, 12.4 (range: 9 to 15) 3 months after surgery, 12.3 (range: 9 to 15) 1 year after surgery, and 11.7 (range: 5 to 15) at the final follow-up. The average recovery rate was 62.1% (range: 40.0% to 81.3%). CONCLUSIONS: This follow-up study confirms that IPPP affords long-lasting improvements in leg symptoms for patients with lumbar foraminal stenosis.