Keishi Maruo

Predictive factors for proximal junctional kyphosis in long fusions to the sacrum in adult spinal deformity

Study Design. A retrospective study. Objective. To assess the mechanisms and the independent risk factors associated with proximal junctional kyphosis (PJK) in patients treated surgically for adult spinal deformity with long fusions to the sacrum. Summary of Background Data. The occurrence of PJK may be related to preoperative and postoperative sagittal parameters. The mechanisms and risk factors for PJK in adults are not well defined. Methods. Consecutive patients who underwent long instrumented fusion surgery (≥6 vertebrae) to the sacrum with a minimum of 2 years of follow-up were retrospectively studied. Risk factors included patient factors, surgical factors, and radiographical parameters such as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis, pelvic tilt, and pelvic incidence. Results. Ninety consecutive patients (mean age, 64.5 yr) met inclusion criteria. Radiographical PJK occurred in 37 of the 90 (41%) patients with a mean follow-up of 2.9 years. The most common mechanism of PJK was fracture at the upper instrumented vertebra (UIV) in 19 (51%) patients. Twelve (13%) patients with PJK were treated surgically with proximal extension of the instrumented fusion. Preoperative TK more than 30°, preoperative proximal junctional angle more than 10°, change in LL more than 30°, and pelvic incidence more than 55° were identified as predictors associated with PJK. Achievement of ideal global sagittal realignment (sagittal vertical axis <50 mm, pelvic tilt <20°, and pelvic incidence-LL <±10°) protected against the development of PJK (19% vs. 45%). A multivariate regression analysis revealed changes in LL more than 30°, and preoperative TK more than 30° were the independent risk factors associated with PJK. Conclusion. Fracture at the UIV was the most common mechanism for PJK. Change in LL more than 30° and pre-existing TK more than 30° were identified as independent risk factors. Optimal postoperative alignment of the spine protects against the development of PJK. A surgical strategy to minimize PJK may include preoperative planning for reconstructions with a goal of optimal postoperative alignment. Level of Evidence: 3

Proximal junctional kyphosis and clinical outcomes in adult spinal deformity surgery with fusion from the thoracic spine to the sacrum: a comparison of proximal and distal upper instrumented vertebrae

OBJECTnProximal junctional kyphosis (PJK) is a common and significant complication after corrective spinal deformity surgery. The object of this study was to compare-based on clinical outcomes, postoperative proximal junctional kyphosis rates, and prevalence of revision surgery-proximal thoracic (PT) and distal thoracic (DT) upper instrumented vertebra (UIV) in adults who underwent spine fusion to the sacrum for the treatment of spinal deformity.nnnMETHODSnIn this retrospective study the authors evaluated clinical and radiographic data from consecutive adults (age > 21 years) with a deformity treated using long instrumented posterior spinal fusion to the sacrum in the period from 2007 to 2009. The PT group included patients in whom the UIV was between T-2 and T-5, whereas the DT group included patients in whom the UIV level was between T-9 and L-1. Perioperative surgical data were compared between the PT and DT groups. Additionally, segmental, regional, and global spinal alignments, as well as the sagittal Cobb angle at the proximal junction, were analyzed on preoperative, early postoperative, and final standing 36-in. radiographs. Patient-reported outcome measurements (visual analog scale, Scoliosis Research Society Patient Questionnaire-22, Oswestry Disability Index, and the 36-Item Short-Form Health Survey) were compared.nnnRESULTSnEighty-nine patients, 22 males and 67 females, had a minimum follow-up of 2 years, and thus were eligible for participation in this study. Sixty-seven patients were in the DT group and 22 were in the PT group. Operative time (p = 0.387) and estimated blood loss (p < 0.05) were slightly higher in the PT group. The overall rate of revision surgery was 48.0% and 54.5% in the DT and PT groups, respectively (p = 0.629). The prevalence of PJK according to radiological criteria was 34% in the DT group and 27% in the PT group (p = 0.609). The percent of patients with PJK that required surgical correction (surgical PJK) was 11.9% (8 of 67) in the DT group and 9.1% (2 of 22) in the PT group (p = 1.0). The onset of surgical PJK was significantly earlier than radiological PJK in the DT group (p < 0.01). The types of PJK were different in the PT and DT groups. Compression fracture at the UIV was more prevalent in the DT group, whereas subluxation was more prevalent in the PT group. Postoperatively, the PT group had less thoracic kyphosis (p = 0.02), less sagittal imbalance (p < 0.01), and less pelvic tilt (p = 0.04). In the DT group, early postoperative radiographs demonstrated that the proximal junctional angle of patients with surgical PJK was greater than in those without PJK and those with radiological PJK (p < 0.01). Clinical outcomes were significantly improved in both groups, and there was no significant difference between the groups.nnnCONCLUSIONSnBoth PT and DT UIVs improve segmental and global sagittal plane alignment as well as patient-reported quality of life in those treated for adult spinal deformity. The prevalence of PJK was not different in the PT and DT groups. However, compression fracture was the mechanism more frequently observed with DT PJK, and subluxation was the mechanism more frequently observed in PT PJK. Strategies to avoid PJK may include vertebral augmentation to prevent fracture at the DT spine and mechanical means to prevent vertebral subluxation at the PT spine.

C-5 palsy after cervical laminoplasty with instrumented posterior fusion

OBJECTnPostoperative C-5 palsy is known as a common complication after cervical laminoplasty. The authors of this article have encountered postoperative C-5 palsy more often when laminoplasty was combined with instrumented posterior spinal fusion than when it was performed alone. The purpose of this clinical study was to examine the incidence of fifth cervical nerve root palsy (C-5 palsy) and surgical results in patients with cervical myelopathy who had undergone laminoplasty with or without instrumented spinal fusion.nnnMETHODSnThe authors retrospectively studied patients with cervical myelopathy who had undergone laminoplasty with or without instrumented posterior spinal fusion.nnnRESULTSnClinical data on 58 patients were evaluated and analyzed. Preoperative diagnoses were cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament of the cervical spine. Twenty-four patients with spondylolisthesis or kyphosis underwent laminoplasty combined with posterior spinal fusion using instrumented lateral mass fixation (fusion group), while the remaining 34 patients underwent laminoplasty without posterior spinal fusion (no-fusion group). In the fusion group, C-5 palsy developed in 6 patients; in the no-fusion group, it occurred in only 1 patient. There was a significant difference in the rate of this complication between the 2 groups. In the fusion group, local kyphosis and spondylolisthesis level were reduced at the fusion level, and all patients with C-5 palsy underwent C4-5 spinal fusion.nnnCONCLUSIONSnThe incidence of postoperative C-5 palsy is significantly higher after laminoplasty when it is combined with spinal fusion. Correction of kyphosis and spondylolisthesis using posterior instrumentation may be a risk factor for iatrogenic intervertebral foraminal stenosis leading to C-5 palsy.

Outcome and treatment of postoperative spine surgical site infections: predictors of treatment success and failure

AbstractBackgroundnSurgical site infection (SSI) is an important complication after spine surgery. The management of SSI is characterized by significant variability, and there is little guidance regarding an evidence-based approach. The objective of this study was to identify risk factors associated with treatment failure of SSI after spine surgery.Patients and methodsA total of 225 consecutive patients with SSI after spine surgery between July 2005 and July 2010 were studied retrospectively. Patients were treated with aggressive surgical debridement and prolonged antibiotic therapy. Outcome and risk factors were analyzed in 197 patients having 1xa0year of follow-up. Treatment success was defined as resolution within 90xa0days.ResultsA total of 126 (76xa0%) cases were treated with retention of implants. Forty-three (22xa0%) cases had treatment failure with five (2.5xa0%) cases resulting in death. Lower rates of treatment success were observed with late infection (38xa0%), fusion with fixation to the ilium (67xa0%), Propionibacterium acnes (43xa0%), poly microbial infection (68xa0%),xa0>6 operated spinal levels (67xa0%), and instrumented cases (73xa0%). Higher rates of early resolution were observed with superficial infection (93xa0%), methicillin-sensitive Staphylococcus aureus (95xa0%), andxa0<3 operated spinal levels (88xa0%). Multivariate logistic regression revealed late infection was the most significant independent risk factor associated with treatment failure. Superficial infection and methicillin-sensitive Staphylococcus aureus were predictors of early resolution.ConclusionPostoperative spine infections were treated with aggressive surgical debridement and antibiotic therapy. High rates of treatment failure occurred in cases with late infection, long instrumented fusions, polymicrobial infections, and Propionibacterium acnes. Removal of implants and direct or staged re-implantation may be a useful strategy in cases with high risk of treatment failure.

The impact of dynamic factors on surgical outcomes after double-door laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine

OBJECTnLaminoplasty is the preferred operation for most patients with cervical myelopathy due to multilevel ossification of the posterior longitudinal ligament (OPLL). Recent studies have demonstrated several significant risk factors for poor clinical outcomes after laminoplasty, including older age, lower preoperative Japanese Orthopaedic Association (JOA) score, postoperative change in cervical alignment, cervical kyphosis, and high occupying ratio of the OPLL (that is, the ratio of the greatest anteroposterior thickness of the OPLL to the anteroposterior diameter of the spinal canal at the same level on a lateral image). However, the impact of dynamic factors on clinical outcomes is unclear. The purpose of this study is to assess the impact of dynamic factors on the clinical outcome after laminoplasty for cervical myelopathy due to OPLL.nnnMETHODSnA consecutive series of patients who underwent laminoplasty for cervical myelopathy due to OPLL between 2003 and 2009 was retrospectively reviewed. The indication for laminoplasty at the authors hospital included preoperative straight or lordotic alignment of the cervical spine and an occupying ratio of OPLL less than 60%. The JOA score and recovery rate were used to evaluate clinical outcomes. A poor clinical outcome was defined as a recovery rate of less than 50%. Patient factors examined along with outcome included age, preoperative JOA score, preoperative somatosensory evoked potentials, preoperative motor evoked potentials, body mass index, and presence of high intensity on MRI. Radiographic measures included the preoperative C2-7 lordotic angle, preoperative C2-7 range of motion (ROM), preoperative segmental ROM at the level of myelopathy, and the occupying ratio of OPLL.nnnRESULTSnThere were 45 patients (33 males and 12 females). The mean follow-up period was 4 years (range 2-6.8 years). The mean patient age was 66.9 years (range 50-85 years). The mean JOA score significantly increased from 9.1 before surgery to 13.1 at the final follow-up. The mean recovery rate was 51.2%. Nineteen patients (42%) had a recovery rate of less than 50%. Patient factors were not associated with surgical outcomes. Only the preoperative C2-7 ROM was significantly greater in the poor surgical outcome group (23.1° vs 14.1°). Receiver operating characteristic curve analysis showed that the optimal preoperative C2-7 ROM cutoff was 20°. Logistic regression analysis revealed that patients with a preoperative C2-7 ROM of greater than 20° had a 4.6 times higher risk (p = 0.021) of a poor clinical outcome, indicating that dynamic factors may have an impact on the surgical outcome of laminoplasty.nnnCONCLUSIONSnFusion surgery may be a useful strategy in patients with preoperative hypermobility of the cervical spine.

Risk factors for intraoperative lateral mass fracture of lateral mass screw fixation in the subaxial cervical spine

OBJECTnAlthough lateral mass screw fixation for the cervical spine is a safe technique, lateral mass fracture during screw fixation is occasionally encountered intraoperatively. This event is regarded as a minor complication; however, it poses difficulties in management that may affect fixation stability and clinical outcome. The purpose of this study is to determine the incidence and etiology of lateral mass fractures during cervical lateral mass screw fixation.nnnMETHODSnA retrospective clinical review of patient records was performed in 117 consecutive patients (mean age 57 years, range 15-86 years) who underwent lateral mass screw fixation using a modified Magerl method from 1997 to 2010 at a single institution. A total of 555 lateral masses were included in this study. The outer diameters of the screws were 3.5 or 4.0 mm. In the retrospective clinical analysis, the incidence of intraoperative lateral mass fractures was reviewed. Potential risk factors for this complication were assessed using multivariate analysis.nnnRESULTSnThe incidence of lateral mass fractures during cervical lateral mass screw fixation was 4.7% (26 lateral masses) among all cases. Among the disorders, the incidence was highest in patients with destructive spondyloarthropathy (DSA) (18.8%, 12 lateral masses). There was no significant difference with respect to lateral mass fracture between the use of 4.0-mm screws (5.6%) and 3.5-mm screws (3.6%). Independent risk factors identified by logistic regression were DSA (OR 7.89, p < 0.001) and screw insertion in the C-6 lateral masses (OR 2.80, p = 0.018).nnnCONCLUSIONSnThe overall incidence of lateral mass fracture during cervical lateral mass screw fixation was 4.7%. Destructive spondyloarthropathy as an underlying cause of morbidity and screw placement in the C-6 lateral mass were identified as independent risk factors. Use of a 4.0-mm screw in patients with DSA may be a principal risk factor for this complication.

Ossified Posterior Longitudinal Ligament With Massive Ossification of the Anterior Longitudinal Ligament Causing Dysphagia in a Diffuse Idiopathic Skeletal Hyperostosis Patient.

AbstractDescriptive case report.To report a case of a diffuse idiopathic skeletal hyperostosis (DISH) patient with both massive ossification of the anterior longitudinal ligament (OALL) leading to severe dysphagia as well as ossification of the posterior longitudinal ligament (OPLL) causing mild cervical myelopathy, warranting not only an anterior approach but also a posterior one.Although DISH can cause massive OALL in the cervical spine, severe dysphagia resulting from DISH is a rare occurrence. OALLs are frequently associated with OPLL. Treatment for a DISH patient with OPLL in setting of OALL-caused dysphagia is largely unknown.A 70-year-old man presented with severe dysphagia with mild cervical myelopathy. Neurological examination showed mild spastic paralysis and hyper reflex in his lower extremities. Plane radiographs and computed tomography of the cervical spine revealed a discontinuous massive OALL at C4-5 and continuous type OPLL at C2-6. Magnetic resonance imaging revealed pronounced spinal cord compression due to OPLL at C4-5. Esophagram demonstrated extrinsic compression secondary to OALL at C4-5.We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. Severe dysphagia markedly improved without any complications.We considered that this patient not only required osteophytectomy and fusion by the anterior approach but also required decompression and spinal fusion by the posterior approach to prevent both deterioration of cervical myelopathy and recurrence of OALL after surgery.

Pharmacological Interventions for Neuropathic Pain Associated withCompressive Myelopathy

Neuropathic pain following spinal cord injury (SCI) is a common problem in patients with SCI, which influences the quality of life of such patients. However, in our experiments of treatments for patients with compressive myelopathy, neuropathic pain was identified in patients with not only SCI, but also those with compressive myelopathy. The objective of this study was the evaluation of pharmacological interventions for neuropathic pain associated with compressive myelopathy (NePCM). Forty-five consecutive patients with NePCM who underwent pharmacological interventions from 2005 to 2016 were included in the study. Patient records were analyzed retrospectively. Evaluated factors were visual analog scale (VAS) and grid score (GS), which were used for quantification of pain. Effective pharmacological interventions were identified when VAS or GS decreased more than 10 points after treatments. The patients’ diagnoses were as follows: cervical or thoracic ossification of posterior longitude ligaments in 17 patients, cervical spondylotic myelopathy in 12 patients, disc herniation in 3 patients, and other diagnoses in 13 patients. All patients received decompression surgery with or without spinal fusion except 7 patients. Cervical lesions were in 32 patients, thoracic lesions were in 11 patients, and both cervical and thoracic lesions were in 2 patients. Pain distribution was at-level in 10 patients, below-level in 23 patients, and both at-level and below-level in 12 patients. Effective interventions were anticonvulsants for 19 patients, antidepressants for 10 patients, and other interventions for 3 patients. The effective anticonvulsants were pregabalin for 9 patients, gabapentin for 6 patients, and chronazepam for 5 patients. The effective antidepressants were duloxetine for 7 patients. However, 15 patients did not respond to any medications. Anticonvulsants and antidepressants are likely to be effective for NePCM, however, some patients do not respond to these interventions. Therefore, advanced treatments have to be developed for NePCM.

Hemothorax caused by the trocar tip of the rod inserter after minimally invasive transforaminal lumbar interbody fusion: case report.

Minimally invasive surgery (MIS) for transforaminal lumbar interbody fusion (MIS-TLIF) is widely used for lumbar degenerative diseases. In the paper the authors report a unique case of a hemothorax caused by the trocar tip of the rod inserter after MIS-TLIF. A 61-year-old woman presented with thigh pain and gait disturbance due to weakness in her lower right extremity. She was diagnosed with a lumbar disc herniation at L1-2 and the MIS-TLIF procedure was performed. Immediately after surgery, the patients thigh pain resolved and she remained stable with normal vital signs. The next day after surgery, she developed severe anemia and her hemoglobin level decreased to 7.6 g/dl, which required blood transfusions. A chest radiograph revealed a hemothorax. A CT scan confirmed a hematoma of the left paravertebral muscle. A chest tube was placed to treat the hemothorax. After 3 days of drainage, there was no active bleeding. The patient was discharged 14 days after surgery without leg pain or any respiratory problems. This complication may have occurred due to injury of the intercostal artery by the trocar tip of the rod inserter. A hemothorax after spine surgery is a rare complication, especially in the posterior approach. The rod should be caudally inserted in the setting of the thoracolumbar spine.

Post-Traumatic Torticollis Due to Odontoid Fracture in a Patient With Diffuse Idiopathic Skeletal Hyperostosis: A Case Report.

AbstractDescriptive case report.To report a rare case of post-traumatic torticollis by odontoid fracture in a patient with diffuse idiopathic skeletal hyperostosis (DISH).Cervical fractures in DISH can result from minor trauma, and a delay in presentation often prevents their timely diagnosis. Cervical fractures in patients with spinal DISH usually occur in extension injuries, and almost always occur in the lower cervical spine. Reports of odontoid fractures with torticollis in patients with spinal DISH are rare.A 73-year-old man with DISH presented with severe neck pain and a cervical deformity presenting as torticollis without neurological deficits. He gave a history of a fall while riding a bicycle at a low speed 3 months ago. X-ray showed torticollis in the right side, and computed tomography (CT) showed a type-II odontoid fracture and subluxation at the C1-2 level.We performed a staged treatment because this patient had severe neck pain associated with a chronic course. Initially, the fracture dislocation was reduced under general anesthesia and was stabilized with a halo vest. We then performed posterior occipitocervical in situ fusion after confirming the correction of the cervical deformity by CT. The patient showed significant amelioration of neck symptoms postoperatively, and bony fusion was achieved 1 year after surgery.For post-traumatic torticollis due to an odontoid fracture, plain CT is useful for diagnosis and posterior occipitocervical in situ fusion following correction and immobilization with a halo vest is a safe and an effective treatment.