Shigenobu Sato

Spinopelvic alignment in patients with osteoarthrosis of the hip: a radiographic comparison to patients with low back pain.

Study Design. A retrospective, age- and sex-matched radiographic study. Objectives. To investigate the spinopelvic alignment in patients with osteoarthosis of the hip (HOA) and those with low back pain (LBP) and to determine the characteristics and differences in both groups. Summary of Background Data. Hip-spine syndrome, first described by Offierski and MacNab, is quite an important pathology when treating patients with pain in their low back and lower extremities. However, despite it being a well-known entity, few papers have adequately investigated and assessed the spinopelvic alignment in patients with hip-spine syndrome. Methods. Sagittal and coronal spinopelvic alignments were investigated in 150 patients with HOA and 150 with LBP using radiographs of the whole spine in both anteroposterior and lateral views. Parameters measured in this study were lumbar lordosis (LL), sacral slope (SS), the shift of the sagittal C7 plumb line, pelvic incidence (PI), and pelvic tilt (PT) on the lateral radiographs. On the anteroposterior (AP) films, lumbar scoliosis, pelvic obliquity, leg length discrepancy, the shift of the coronal C7 plumb line, and Sharp angle were measured. These parameters were compared between the two groups. In patients with HOA, the relationships between Sharp angle and other parameters were also analyzed to clarify the possible influence of sagittal and coronal spinopelvic alignments on HOA without acetabular dysplasia. Results. LL, SS, PI, and PO were found to be less in patients with LBP compared with those with HOA, and there was no significant difference in LS between the two groups. PI was significantly greater in HOA patients and strongly correlated to PT, SS, and LL (i.e., as the PI increased so did the PT, SS, and LL). Sharp angles were also significantly greater in HOA patients and strongly correlated to age, LL and SS (i.e., as Sharp angles increased so did LL and SS); however, age decreased in the hip patients. Conclusions. These findings suggest that higher PI in the younger individual may contribute to the development of HOA in later life without both lumbar kyphosis and acetabular dysplasia because of the anterior uncovering of the acetabulum. More investigation will be expected to analyze the spinopelvic alignment in patients with hip spine syndrome.

Spinal reconstruction using a cervical pedicle screw system.

Although the cervical pedicle screw system is considered the most effective instrumentation for posterior cervical spine surgery, reports on clinical application are limited because of the unresolved and inherent risk of neurovascular complications. The purpose of this study is to retrospectively evaluate the accuracy of placement and clinical effectiveness of the cervical pedicle screw. The cases of 26 patients were investigated. The average followup was 20 months. All but one patient had simultaneous decompression and fusion of various extent. In these cases, screw placement, alignment of the fused segment, fusion rate, neurologic improvement, and complications were assessed. Using an image intensifier, 134 screws were inserted. Five screws (3.7%) completely perforated and 10 (7.4%) partially perforated. The complete perforations occurred in the first 10 patients. Except for two patients with metastasis, bony union was obtained in all patients without loss of correction. Neurologic impairment also was improved in all patients, and no complications associated with the cervical pedicle screw were seen. Clinical results of the cervical pedicle screw system were excellent with few complications. However, there is the possibility of screw perforation, which could cause neurovascular complications. Increased accuracy of screw insertion is needed to make this instrumentation safer. Level of Evidence: Therapeutic study, Level IV (case series—no, or historical control group)

A Prospective Evaluation of Anesthesia for Posterior Lumbar Spine Fusion: The Effectiveness of Preoperative Epidural Anesthesia With Morphine

Study Design. A prospective, randomized, single-blinded study. Objectives. To prospectively compare the anesthesia for posterior lumbar spinal fusion between the age- and gender-matched groups with and without preoperative epidural anesthesia with morphine. Summary of Background Data. To reduce the blood loss, hypotensive anesthesia is frequently used in the spinal fusion. However, in spite of administration of the hypotensive agents, inadequate analgesia during operation often causes unfavorable and unexpected elevation of blood pressure resulting in excessive bleeding. As well, intractable wound pain sometimes occurs after spinal fusion due to inadequate analgesia during surgery. Methods. Forty cases of posterior lumbar spinal fusion were investigated prospectively. Twenty patients underwent preoperative epidural anesthesia with morphine and sedation by continuous intravenous administration of propofol but without administration of any kind of anesthetics, including intraoperative and/or postoperative epidural anesthesia (Group E). Another 20 patients underwent inhalation general anesthesia with sevoflurane and intermittent intravenous administration of fentanyl without any regional block (Group F). In these groups, dynamics and average mean blood pressure during surgery, blood loss during surgery, postoperative requirement of analgesics, the visual analogue scale, and accuracy of neurologic evaluation immediately after surgery were analyzed. Results. The average mean blood pressure during surgery was significantly lower in Group E than Group F: 57.1 mm Hg and 72.8 mm Hg, respectively. In addition, the dynamics of blood pressure were more stable in Group E than Group F. The blood loss during surgery was significantly less in Group E than in Group F: 546 g and 631 g, respectively. The patients of Group E required analgesics after surgery less frequently, and the rating on the visual analogue scale was significantly lower in Group F on the first, second, and third days after surgery. It was difficult to evaluate the neurologic status accurately in 5 patientsof Group F because of the inadequate emergence immediately after surgery. There were no patients in Group E whose neurologic status was unclear because of the paralysis caused by epidural anesthesia. Conclusions. To combine preoperative epidural anesthesia with other anesthetic procedure for spinal fusion contributes to maintain more stable hypotension during surgery. As a result, it will be possible to lessen the bleeding during surgery. In addition, the postoperative pain was easily controlled with administration of fewer analgesic agents in patients who underwent the epidural anesthesia. The effectiveness of pre-emptive analgesia should be emphasized to diminish the postoperative pain.

A novel 3D guidance system using augmented reality for percutaneous vertebroplasty: technical note.

Augmented reality (AR) is an imaging technology by which virtual objects are overlaid onto images of real objects captured in real time by a tracking camera. This study aimed to introduce a novel AR guidance system called virtual protractor with augmented reality (VIPAR) to visualize a needle trajectory in 3D space during percutaneous vertebroplasty (PVP). The AR system used for this study comprised a head-mount display (HMD) with a tracking camera and a marker sheet. An augmented scene was created by overlaying the preoperatively generated needle trajectory path onto a marker detected on the patient using AR software, thereby providing the surgeon with augmented views in real time through the HMD. The accuracy of the system was evaluated by using a computer-generated simulation model in a spine phantom and also evaluated clinically in 5 patients. In the 40 spine phantom trials, the error of the insertion angle (EIA), defined as the difference between the attempted angle and the insertion angle, was evaluated using 3D CT scanning. Computed tomography analysis of the 40 spine phantom trials showed that the EIA in the axial plane significantly improved when VIPAR was used compared with when it was not used (0.96° ± 0.61° vs 4.34° ± 2.36°, respectively). The same held true for EIA in the sagittal plane (0.61° ± 0.70° vs 2.55° ± 1.93°, respectively). In the clinical evaluation of the AR system, 5 patients with osteoporotic vertebral fractures underwent VIPAR-guided PVP from October 2011 to May 2012. The postoperative EIA was evaluated using CT. The clinical results of the 5 patients showed that the EIA in all 10 needle insertions was 2.09° ± 1.3° in the axial plane and 1.98° ± 1.8° in the sagittal plane. There was no pedicle breach or leakage of polymethylmethacrylate. VIPAR was successfully used to assist in needle insertion during PVP by providing the surgeon with an ideal insertion point and needle trajectory through the HMD. The findings indicate that AR guidance technology can become a useful assistive device during spine surgeries requiring percutaneous procedures.

The impact of the leg-lengthening total hip arthroplasty on the coronal alignment of the spine

BackgroundCoronal imbalance of the pelvis is recognized to lead to the development of degenerative lumbar scoliosis. We hypothesized that an abrupt change of pelvic obliquity may show a reproducible trend of coronal compensation in the lumbosacral spine. The aim of the study was to classify the change of coronal alignment of spine after THA.MethodsThis is a retrospective study based on the radiological analysis of 195 patients who underwent THA between 2009 and 2010. The mean age at surgery was 61.5 years old, and minimum follow up period was 24 months. Pelvic obliquity (POb) and Cobb’s angle of lumbar scoliosis (LS) in coronal plane were measured. Over 3.5 degrees of change in POb was regarded as ΔPOb(+) and over 10 degrees of lumbar scoliosis was regarded as LS(+). The change of LS were classified into 3 subtypes; ΔLS(+), over 5 degrees of progress in LS, ΔLS(-), over 5 degrees of improvement in LS, and ΔLS(n), changes in LS within 5 degrees.ResultsOver 3.5 degrees of change in POb was significantly correlated with the change in LS. Among195 patients, 120 patients improved their pelvic obliquity (ΔPOb(+)), and 75 patients did not have an improved pelvic obliquity (ΔPOb(-)). 99 patients out of 120 ΔPOb(+) patients did not show changes (54, ΔLS(n)) or improvement in scoliosis (45, ΔLS(-)).The remaining 21 patients showed progress or development of de novo scoliosis. Patients who failed to compensate for the POb change at lumbosacral area developed de novo lumbar scoliosis (7 cases), showed progression in lumbar scoliosis (7 cases) or developed coronal trunk shift over 20mm (7 cases)ConclusionsThe patterns of compensation in lumbar or lumbosacral spine in coronal plane after leg lengthening THA were classified with regards to pelvic obliquity and Cobb’s angle. 89.2% of 195 patients showed acceptable compensation in lumbar spine, 21 patients developed coronal imbalance. THA therefore is considered to be safe, as regards to spinal balance in coronal plane. However we have to keep in mind that preoperative rigid scoliosis could have a risk in progress for spinal imbalance.

Mid- and long-term clinical outcomes of corrective fusion surgery which did not acquired sufficient PI-LL value for adult spinal deformity

Objective Recent studies have demonstrated sagittal spinal balance was more important than coronal balance in terms of clinical result of surgery for adult spinal deformity. Notably, Schwab reported one of the target spinopelvic parameters for corrective surgery was that lumbar lordosis (LL) should be within +/10 degrees of pelvic incidence (PI). The present study was aimed to investigate whether the clinical outcome of corrective fusion surgery was really poor for patients who could not be acquired sufficient PI-LL value by the surgery.