Ureter position and risk of ureteral injury during lateral lumbar interbody fusion.

BACKGROUND: Ureteral injury during lateral lumbar interbody fusion (LLIF) is uncommon. However, it is a serious complication that may require additional surgery should it occur. The objective of this study was to evaluate whether there was any change in the position of the left ureter between preoperative biphasic contrast-enhanced CT scanned in the supine position and intraoperative scanning in the right lateral decubitus position after stent placement, to assess the risk of ureteral injury in the actual surgical position. METHODS: The position of the left ureter scanned with the O-arm navigation system with the patient in the right lateral decubitus position and its position on preoperative biphasic contrast-enhanced CT images scanned with the patient in the supine position were investigated comparing their positions at the L2/3, L3/4, and L4/5 levels. RESULTS: The ureter was located along the interbody cage insertion trajectory in 25 of 44 disc levels (56.8%) in the supine position, but in only 4 (9.5%) in the lateral decubitus position. The proportion of patients in whom the left ureter was located lateral to the vertebral body (along the LLIF cage insertion trajectory) at each level was 80% in the supine position and 15.4% in the lateral decubitus position at the L2/3 level, 53.3% in the supine position and 6.7% in the lateral decubitus position at the L3/4 level, and 33.3% in the supine position and 6.7% in the lateral decubitus position at the L4/5 level. CONCLUSION: The proportion of patients in whom the left ureter was located on the lateral surface of the vertebral body when the patient was in the actual surgical position (lateral decubitus position) was 15.4% at the L2/3 level, 6.7% at the L3/4 level, and 6.7% at the L4/5 level, suggesting that caution is required during LLIF surgery.

The impact of helicopter emergency medical services and craniocervical traction on the early reduction of cervical spine dislocation in a rural area of Japan.

BACKGROUND: Several studies have shown an association between achieving decompression of the spinal cord within a few hours and neurological recovery, even in patients with complete paralysis due to cervical spine dislocation. This study aimed to clarify the impact of helicopter emergency medical services (HEMSs) and craniocervical traction on the rapid reduction of lower cervical spine dislocation in rural Japan. METHODS: The success rate of and factors inhibiting closed reduction, the time from injury to reduction and the functional prognosis of lower cervical spine dislocations treated between July 2012 and February 2020 were retrospectively analysed. RESULTS: Fourteen patients were transported by HEMS (group H), seven by ambulance (group A) and two by themselves. Although the average traveled distance and injury severity score were significantly higher in group H (64.5 km, 28.0) than in group A (24.7 km, 18.6), there was no significant difference in the average time to admission or the time to initiation of craniocervical traction after admission between groups H (159.4 min, 52.2 min) and A (163.6 min, 53.2 min). The success rate of closed reduction was 95%, and neurological deterioration was not observed in any cases. The average traction time and weight for reduction were 30.3 min and 16.3 kg, respectively. Body size and fracture-dislocation type did not significantly affect the traction time or weight. The rate of reduction within 4 h after injury was higher in group H (79%) than in group A (33%). Inner fixations were treated an average of 5.7 days after admission. After treatment, three of nine AIS A patients recovered the ability to walk, and all three patients underwent successful closed reduction within 4 h after injury. CONCLUSION: HEMS and highly successful closed reduction contributed to the early reduction of cervical spine dislocation and can potentially improve complete paralysis.

Sarcopenia, Ectopic Fat Infiltration Into the Lumbar Paravertebral Muscles, and Lumbo-Pelvic Deformity in Older Adults Undergoing Lumbar Surgery.

STUDY DESIGN: A retrospective analysis of a prospective, non-randomized cohort dataset. OBJECTIVE: To cross-sectionally examine the prevalence of sarcopenia and the association between spine-pelvic deformity and skeletal muscle volume loss and ectopic fat infiltration into lumbar paravertebral muscles (PVMs) in patients who underwent lumbar surgery. SUMMARY OF BACKGROUND DATA: Muscle quality deterioration has been considered the main pathology of sarcopenia, reducing muscle strength directly. The qualitative deterioration as well as volume loss in PVM, which contributes significantly to core body extension, might cause aging-related spine deformity. METHODS: In total, 184 patients were included. Sarcopenia was diagnosed at baseline, and all patients underwent whole-body X-ray. The amount of fat in lumbar PVM was evaluated with the Goutallier classification in magnetic resonance imaging findings. The expression of adipogenesis- and atrophy-promoting factors in PVM was evaluated with quantitative polymerase chain reaction. RESULTS: In total, 36.1% of adults aged ≥60 years were diagnosed with sarcopenia. The values of skeletal muscle indexes of the limb and trunk were inversely correlated with the sagittal vertical axis, pelvic tilt (PT), and pelvic incidence minus lumbar lordosis (PI-LL) values. The PT and PI-LL were greater, PVM area was smaller, and Goutallier grade was greater in sarcopenic adults than in non-sarcopenic older adults. Additionally, the PVM area correlated with the LL value, and Goutallier's grade correlated with the PT and PI-LL values. Moreover, the amount of ectopic fat in PVMs inversely correlated with skeletal muscle indexes. The expression levels of atrophy gene-1 and muscle ring-finger protein-1 did not differ between the groups and did not correlate with the PVM area. In contrast, the expression of Pparg and Cebpa was upregulated in sarcopenic older adults, where it correlated with Goutallier's grade. CONCLUSION: The volume loss of skeletal muscle, including lumbar PVM, and ectopic fat infiltration into the PVM, may cause the lumbo-pelvic deformity.Level of Evidence: 3.

Evaluation of cervical ossification of the posterior longitudinal ligament with 3D broadband IR-prepared ultrashort echo-time imaging: a pilot study.

PURPOSE: We aimed to evaluate the feasibility of 3D broadband inversion-recovery-prepared ultrashort echo-time (3D IRP UTE) imaging for assessing ossification of the posterior longitudinal ligament (OPLL). MATERIALS AND METHODS: The study consisted of 25 consecutive patients with cervical OPLL [13 women, 12 men; mean age 66.3 (47-84) years] who underwent CT, 3T conventional MR, and 3D IRP UTE imaging studies. Two readers independently assessed the 3D IRP UTE images for the type (mixed, continuous, circumscribed, segmental) and distribution of OPLL. All readers consensually assessed the diagnostic certainty of OPLL on conventional MR and 3D IRP UTE images by using a 3-point scale system. Interobserver and intermodality agreement was assessed by κ statistics. A Wilcoxon signed-rank test was used to evaluate the difference of diagnostic certainty between conventional MR and 3D IRP UTE imaging. RESULTS: Interobserver and intermodality agreements were good (κ = 0.73) and excellent (κ = 0.81) for the OPLL type, and excellent (κ = 0.85) and good (κ = 0.76) for the assessment of the distribution of OPLL, respectively. The mean level of the diagnostic certainty of OPLL was significantly higher for 3D IRP UTE than conventional MR imaging (p = 0.002). CONCLUSION: 3D IRP UTE imaging may be useful for assessing OPLL.

Efficacy of the Osaka Medical College (OMC) brace in the treatment of adolescent idiopathic scoliosis following Scoliosis Research Society brace studies criteria.

BACKGROUND: The efficacy of brace treatment for patients with adolescent idiopathic scoliosis (AIS) remains controversial. To make comparisons among studies more valid and reliable, the Scoliosis Research Society (SRS) has standardized criteria for brace studies in patients with AIS. The purpose of this study was to evaluate the efficacy of the Osaka Medical College (OMC) brace for AIS in accordance with the modified standardized criteria proposed by the SRS committee on bracing and non-operative management. METHODS: From 1999 through 2010, 31 consecutive patients with AIS who were newly prescribed the OMC brace and met the modified SRS criteria were studied. The study included 2 boys and 29 girls with a mean age of 12 years and 0 month. Patients were instructed to wear the brace for a minimum of 20 hours per day at the beginning of brace treatment. The mean duration of brace treatment was 4 years and 8 months. We examined the initial brace correction rate and the clinical outcomes of main curves evaluated by curve progression and surgical rate, and the compliance evaluated by the instruction adherence rate for all cases. The clinical course of the brace treatment was considered progression if ≥6° curvature increase occurred and improvement if ≥6° curvature decrease occurred according to SRS judgment criteria. RESULTS: The average initial brace correction rate was 46.8%. In 10 cases the curve progressed, 6 cases the curve improved, and 15 cases the curve remained unchanged (success rate: 67.7%). The mean instruction adherence rate, that was defined the percentage of the visits that patients declared they mostly followed our instruction to total visits, was 53.7%. The success rate was statistically higher in the patient group whose instruction adherence rate was greater than 50% (88.2%) as compared with in those 50% or less (42.8%). CONCLUSIONS: OMC brace treatment for AIS patients could alter the natural history and significantly decreased the progression of curves to the threshold for surgical intervention. Better instruction adherence of brace wear associated with greater success.

Predictive factors of Osaka Medical College (OMC) brace treatment in patients with adolescent idiopathic scoliosis.

BACKGROUND: Factors influencing clinical course of brace treatment apply to adolescent idiopathic scoliosis (AIS) patients remain unclear. By making clear them, we may select suitable patients for brace treatment and alleviate overtreatment. The purpose of this study was to explore predictive factors of Osaka Medical College (OMC) brace treatment for AIS patients in accordance with the modified standardized criteria proposed by the Scoliosis Research Society (SRS) committee on bracing and non-operative management. METHODS: From 1999 through 2010, 31 consecutive patients with AIS who were newly prescribed the OMC brace and met the modified SRS criteria were studied. The study included 2 boys and 29 girls with a mean age of 12 years and 0 month. We investigated the clinical course and evaluated the impacts of compliance, initial brace correction rate, curve flexibility, curve pattern, Cobb angle, chronological age, and Risser stage to clinical outcomes. The clinical course of the brace treatment was considered progression if ≥6° curvature increase occurred and improvement if ≥6° curvature decrease occurred according to SRS judgment criteria. RESULTS: The curve progressed in 10 cases, the curve improved in 6 cases, and the curve remained unchanged in 15 cases (success rate: 67.7%). The success rate was statistically higher in the patient group whose instruction adherence rate was greater than 50% as compared with in those 50% or less. Initial brace correction rate, curve flexibility, curve pattern, the magnitude of Cobb angle, chronological age, and Risser stage did not have any significant effect for clinical courses. However, success rate was insignificantly higher in the cases whose Cobb angle in brace was smaller than that in hanging position. CONCLUSIONS: OMC brace treatment could alter the natural history of AIS, however, that was significantly affected by compliance of brace wear.

Significance of hanging total spine x-ray to estimate the indicative correction angle by brace wearing in idiopathic scoliosis patients.

BACKGROUND: Although most idiopathic scoliosis patients subject to conservative treatment in daily clinical practice, there have been no ideal methods to evaluate the spinal flexibility for the patients who are scheduled the brace treatment. The purpose of this study was to investigate the value of hanging total spine x-ray to estimate the indicative correction angle by brace wearing in idiopathic scoliosis patients. METHODS: One hundred seventy-six consecutive patients with idiopathic scoliosis who were newly prescribed the Osaka Medical College (OMC) brace were studied. The study included 14 boys and 162 girls with a mean age of 13 years and 1 month. The type of curves consisted of 62 thoracic, 23 thoracolumbar, 22 lumbar, 42 double major, 14 double thoracic, and 13 triple curve pattern. We compared the Cobb angles on initial brace wearing (BA) and in hanging position (HA). Of those, 108 patients who had main thoracic curves were selected and evaluated the corrective ability of OMC brace. These subjects were divided into three groups according to the relation between BA and HA (BA < HA group, BA = HA group, and BA > HA group), and then, maturity was compared among them. RESULTS: The average Cobb angle in upright position (UA) of all cases was 31.0 ± 7.8°. The average BA and HA of all cases were 20.3 ± 9.5° and 21.1 ± 8.4°, respectively. The average chronological age was lowest in BA < HA group. And also, maturity in BA < HA group was the lowest among each of them. The rate of BA < HA cases were decreased as the Risser stage of the patients were progressed. CONCLUSIONS: The use of hanging total spine x-ray served as a useful tool to estimate the degree of correction possible curve within the OMC brace for main thoracic curve in idiopathic scoliosis. Maturity had some influence on the correlation between HA and BA. Namely, in immature patients, HA tended to be larger than BA. In contrast, in mature patients, HA had a tendency to be smaller than BA. With consideration for spinal flexibility based on maturity, in mature patients, larger BA than HA may be allowed. However, in immature patients, smaller BA than HA should be aimed.

Posterior occipito-axial fixation applied C2 laminar screws for pediatric atlantoaxial instability caused by Down syndrome: Report of 2 cases.

BACKGROUND: Upper cervical spine instability is one of the most critical orthopedic problems in patients with Down syndrome. However, arthrodesis of the upper cervical spine in these patients can be very difficult to achieve and has a high complication rate because of mental retardation and accompanying various medical conditions of the vital organs. Even now, surgeries in such patients, especially pediatric cases, are challenging and the optimal operative procedure remains unsettled. The purpose of this study was to report 2 cases of pediatric atlantoaxial instability due to Down syndrome in which posterior occipito-axial fixation with C2 laminar screws was performed. METHODS: Case 1 was a girl aged 6 years 10 months who had atlantoaxial rotatory fixation with os odontoideum. Atlantoaxial rotatory fixation was incompletely reduced by halo traction, and it was not maintained without halo-ring and -vest fixation. Posterior occipito-axial fixation with bilateral C2 laminar screws was then performed. Case 2 was a boy aged 10 years 7 months who had atlantoaxial subluxation with os odontoideum. He also had incomplete quadriplegia, so he could neither walk nor have a meal by himself. Posterior occipito-axial fixation with right C2 pedicle and left C2 laminar screws was then carried out. RESULTS: In case 1 bone union was obtained at 3 months after surgery and the patient's symptoms were resolved. In case 2 bone union was obtained at 3 months after surgery and the paralysis was improved. CONCLUSIONS/LEVEL OF EVIDENCE: In cases of atlantoaxial instability due to Down syndrome, symptomatic patients often present between ages 5 and 15 years and mental retardation interferes with postoperative cervical immobilization. C2 laminar screws can be safely applied for the pediatric axis and biomechanically accomplished rigid fixation. The C2 laminar screw is one of the most useful options to achieve stability of the pediatric atlantoaxial complex without the risk of vertebral artery injuries (level IV case series).