Paraplegic patients: how to measure balance and what is normal or functional?

Purpose

To review the current understanding and data of sagittal balance and alignment considerations in paraplegic patients.

Methods

A PubMed literature search was conducted to identify all relevant articles relating to sagittal alignment and sagittal balance considerations in paraplegic and spinal cord injury patients.

Results

While there are numerous studies and publications on sagittal balance in the ambulatory patient with spinal deformity or complex spine disorders, there is paucity of the literature on “normal” sagittal balance in the paraplegic patients. Studies have reported significantly alterations of the sagittal alignment parameters in the non-ambulatory paraplegic patients compared to ambulatory patients. The variability of the alignment changes is related to the differences in the level of the spinal cord injury and their differences in the activations of truncal muscles to allow functional movements in those patients, particularly in optimizing sitting and transferring. Surgical goal in treating paraplegic patients with complex pathologies should not be solely directed to achieve the “normal” radiographic parameters of sagittal alignment in the ambulatory patients. The goal should be to maintain good coronal balance to allow ideal sitting position and to preserve motion segment to optimize functions of paraplegia patients.

Conclusion

Current available literature data have not defined normal sagittal parameters for paraplegic patients. There are significant differences in postural sagittal parameters and muscle activations in paraplegic and non-spinal cord injury patients that can lead to differences in sagittal alignment and balance. Treatment goal in spine surgery for paraplegic patients should address their global function, sitting balance, and ability to perform self-care rather than the accepted radiographic parameters for adult spinal deformity in ambulatory patients.

     

Impact of lumbar fusion on spinopelvic sagittal alignment from standing to sitting position: which factor is associated with postoperative functional limitations due to lumbar stiffness?

Purpose

To investigate the impact of lumbar fusion on spinopelvic sagittal alignment from standing to sitting position and the influencing factors of postoperative functional limitations due to lumbar stiffness.

Methods

A total of 107 patients who undertook posterior lumbar interbody fusion were included. Patients were divided into two groups: Group A (lumbosacral fusion; n = 43) and Group B (floating fusion; n = 64). Spinopelvic parameters in standing and sitting position including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), fusion segment lordosis (FSL), upper residual lordosis (URL), lower residual lordosis (LRL), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), sagittal vertical axis (SVA) and T1 pelvic angle (TPA) were measured before and after lumbar fusion. The Lumbar Stiffness Disability Index (LSDI) was used to assess functional limitations due to lumbar stiffness.

Results

Accompanied by increased postoperative LSDI, the values of changes from standing to sitting (∆) were reduced in some parameters compared with the preoperative values. ∆PT and ∆SS significantly decreased in both two groups. In Group A, ∆LL significantly decreased with increased ∆URL. In Group B, ∆LL, ∆URL and ∆LRL showed no significant difference before and after surgery. Multiple linear regression analysis showed that age and ∆PT independently influenced the postoperative LSDI in Group A.

Conclusion

After lumbar fusion, changes of lumbopelvic sagittal parameters from standing to sitting would be restricted. Adjacent segment lordosis could partially compensate for this restriction. For patients with lumbosacral fusion, postoperative functional limitations due to lumbar stiffness were related to age and the postoperative ∆PT from standing to sitting.

     

Characteristics and surgical management of neuropathic (Charcot) spinal arthropathy after spinal cord injury

Background contextNeuropathic (Charcot) spinal arthropathy (CSA) is a rare but progressive and severe degenerative disease that develops in the absence of deep sensation, for example, after spinal cord injury. The diagnosis of CSA is often delayed as a result of the late onset or slow progression of the disease and the nonspecific nature of the reported clinical signs. Considering risk factors of CSA in combination with the common clinical signs may facilitate timely diagnosis and prevent severe presentation of the disease. However, there is a lack of data concerning the early signs and risk factors of CSA. Furthermore, the complications and outcomes after surgical treatment are documented insufficiently.PurposeTo investigate the early signs and risk factors of CSA after spinal cord injury, as well as the complications and outcome after surgical treatment.Study designRetrospective case series from a single center.Patient sampleTwenty-eight patients with 39 Charcot joints of the spine.Outcome measuresClinical signs, radiological signs, risk factors, and complications.MethodsThe case histories and radiological images of patients suffering from CSA were investigated.ResultsThe first clinical symptoms included spinal deformity, sitting imbalance, and localized back pain. Long-segment stabilization, laminectomy, scoliosis, and excessive loading of the spine were identified as risk factors for the development of the disease. Postoperative complications included implant loosening, wound healing disturbance, and development of additional Charcot joints. All patients were able to return to their previous levels of activities.ConclusionsRadiological follow-up of the entire thoracic and lumbar spine should be performed in paraplegic patients. Risk factors in combination with typical symptoms should be considered to facilitate early detection. Functional restoration can be achieved with appropriate surgical techniques.     

Sagittal lumbar and pelvic alignment in the standing and sitting positions

BackgroundThe sitting position has become the most common posture in today’s workplace. In relation to this position, kinematic analysis of the lumbar spine is helpful in understanding the causes of low back pain and its prevention.MethodsIn this study, we investigated the relationship between sagittal lumbar alignment and pelvic alignment in the standing and sitting positions for 50 healthy adults. Lumbar lordotic angle (LLA), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI) were measured on lateral lumbar spine standing and sitting radiographs.ResultsRegarding changes from the standing to sitting positions, averageLLA, SS, and PT were ?16.6° (?49.8 %), ?18.7° (?50.3 %), and 18.3° (284.8 %), respectively (P < 0.01). In the sitting position, lumbar lordosis was reduced and pelvic rotation became posterior.ConclusionsThis study showed that LLA decreased by approximately 50 % and PT increased by approximately 25 % in the sitting position compared with the standing position. No significant gender differences were observed for LLA, SS, and PT in the standing position. In the sitting position, however, LLA and SS were markedly larger for women.     

The role of minimally invasive lateral lumbar interbody fusion in sagittal balance correction and spinal deformity

Purpose

The recent proliferation of minimally invasive lateral lumbar interbody fusion (LLIF) techniques has drawn attention to potential for these techniques to control or correct sagittal misalignment in adult spinal deformity. We systemically reviewed published studies related to LLIF use in adult spinal deformity treatment with emphasis on radiographic assessment of sagittal balance.

Methods

A literature review was conducted to examine studies focusing on sagittal balance restoration in adult degenerative scoliosis with the LLIF approach.

Results

Fourteen publications, 12 retrospective and 2 prospective, reported data regarding lumbar lordosis correction (1,266 levels in 476 patients) but only two measured global sagittal alignment.

Conclusion

LLIF appears to be especially effective when the lumbar lordosis and sagittal balance correction goals are less than 10° and 5 cm, respectively. However, the review demonstrated a lack of consistent reporting on sagittal balance restoration with the MIS LLIF techniques.

     

Can Flexed-Seated and Single-Leg Standing Radiographs Be Useful in Preoperative Evaluation of Lumbar Mobility in Total Hip Arthroplasty?

BackgroundThe purpose of this study is to determine whether simulated radiographs in the “flexed-seated” or “step-up” positions better demonstrate a patient’s range of spinopelvic motion between standing and sitting positions than relaxed sitting and standing radiographs.MethodsAn institutional review board approved cohort of 43 patients with hip osteoarthritis whom underwent full body sitting-standing radiographs from August 2016 to December 2017 at a single institution was reviewed. Subjects underwent single-leg step-up standing and flexed-seated radiographs, and relaxed standing and sitting radiographs. Sacral slope, spinopelvic tilt (SPT), and lumbar lordosis were measured in all radiographs. Alignment parameters were compared between both sets of imaging, and the change in SPT between the imaging modalities was plotted and stratified by pre-existing lumbar pathology.ResultsThere were significant differences between the relaxed standing and step-up radiographs and the relaxed and flexed-seated radiographs for sacral slope, SPT, and lumbar lordosis (P < .002 for all), with the exception of SPT in the relaxed and step-up standing postures (P = .110). When transitioning from the standing to sitting position, the mean changes in SPT differed significantly between both sets of radiographs. Most importantly, when plotting changes in SPT between flexed and relaxed sitting postures, patients with fusions and flatback deformity trended toward greater anterior pelvic tilting, a position of greater risk of posterior dislocation.ConclusionFlexed sitting and single-leg standing imaging may emphasize the compensatory mechanisms of patients with concomitant hip and spine pathology more than relaxed imaging using our measurements. Our method may provide insight into high dislocation risk patients compared to the previously published hip measurement method.Level of EvidenceIII.     

Loading of the lumbar spine during transition from standing to sitting: effect of fusion versus motion preservation at L4–L5 and L5–S1

BACKGROUND CONTEXTTransition from standing to sitting significantly decreases lumbar lordosis with the greatest lordosis-loss occurring at L4–S1. Fusing L4–S1 eliminates motion and thus the proximal mobile segments maybe recruited during transition from standing to sitting to compensate for the loss of L4–S1 mobility. This may subject proximal segments to supra-physiologic flexion loading.PURPOSEAssess effects of instrumented fusion versus motion preservation at L4–L5 and L5–S1 on lumbar spine loads and proximal segment motions during transition from standing to sitting.STUDY DESIGNBiomechanical study using human thoracolumbar spine specimens.METHODSA novel laboratory model was used to simulate lumbosacral alignment changes caused by a person's transition from standing to sitting in eight T10-sacrum spine specimens. The sacrum was tilted in the sagittal plane while constraining anterior-posterior translation of T10. Continuous loading-data and segmental motion-data were collected over a range of sacral slope values, which represented transition from standing to different sitting postures. We compared different constructs involving fusions and motion preserving prostheses across L4–S1.RESULTSAfter L4–S1 fusion, the sacrum could not be tilted as far posteriorly compared to the intact spine for the same applied moment (p<.001). For the same reduction in sacral slope, L4–S1 fusion induced 2.9 times the flexion moment in the lumbar spine and required 2.4 times the flexion motion of the proximal segments as the intact condition (p<.001). Conversely, motion preservation at L4–S1 restored lumbar spine loads and proximal segment motions to intact specimen levels during transition from standing to sitting.CONCLUSIONSIn general, sitting requires lower lumbar segments to undergo flexion, thereby increasing load on the lumbar disks. L4–S1 fusion induced greater moments and increased flexion of proximal segments to attain a comparable seated posture. Motion preservation using a total joint replacement prosthesis at L4–S1 restored the lumbar spine loads and proximal segment motion to intact specimen levels during transition from standing to sitting.CLINICAL SIGNIFICANCEAfter L4–S1 fusion, increased proximal segment loading during sitting may cause discomfort in some patients and may lead to junctional breakdown over time. Preserving motion at L4–S1 may improve patient comfort and function during activities of daily living, and potentially decrease the need for adjacent level surgery.     

The effect of intraoperative lidocaine administration in a disrupted erector spinae fascial plane on intercostal transcranial motor evoked potentials

Study objectiveErector spinae plane (ESP) blocks have been recently described for postoperative pain management following spine surgery but their effects on intraoperative neuromonitoring are unknown.DesignRetrospective cohort study.SettingPediatric patients at a tertiary care center.Patients26 pediatric patients who received bilateral surgically-placed ESP catheters for single-stage posterior spine fusion (PSF) from August 2020 to June 2021.InterventionsPatients in this study did not receive any special interventions as part of this observational retrospective study.MeasurementsThis retrospective study investigated the effects of local anesthesia administration through bilateral surgically-placed ESP catheters on intraoperative intercostal transcranial motor evoked potentials (tcMEPs) in the setting of a disrupted erector spinae fascial plane in pediatric patients undergoing single-stage posterior spine fusion.Main resultsOf the 26 patients that received bilateral surgically-placed ESP catheters for pediatric posterior spine fusion surgery, none exhibited any changes in intercostal tcMEPs attributable to intraoperative lidocaine administration through the ESP catheters.ConclusionsThe administration of a local anesthetic into a disrupted erector spinae fascial plane does not appear to interfere with intraoperative neuromonitoring of posterior spine fusion surgeries.     

Transforaminal Posterior Approach Is Effective for Treatment of Lower Thoracic Spine Spondylodiscitis

Background

Patients with lower-thoracic spine pathologies that affect anterior column stability and compress the neural tissues need anterior decompression and reconstruction. Anterior approaches result in long-term morbidities. Posterior laminectomy and fixation alone may not be sufficient to maintain spine stability.

Questions/Purposes

To evaluate the results of a posterior-only transforaminal thoracic interbody fusion approach for patients with thoracic disc space infection in terms of the improvement in neurologic status, resolution of infection, correction of kyphotic deformity, and assessment of post-operative complications.

Methods

A prospective study was done on 40 patients with lower thoracic spine spondylodiscitis. All patients were assessed with pre-operative imaging. Neurologic assessment was performed using the American Spinal Injury Association (ASIA) Impairment Scale and functionally by the modified Japanese Orthopedic Association (JOA) scale. Pre-operative and post-operative white blood cell count, erythrocyte sedimentation rate, and C-reactive protein levels were compared. All patients were operated on through a posterior approach using the transforaminal thoracic interbody fusion for decompression, reconstruction, and anterior fusion.

Results

Mean age of patients was 49 years; mean operative period was 188 min; mean blood loss was 611 mL. Twelve patients’ ASIA scores improved and only two patients’ scores declined. One patient died 11 months post-operatively due to septicemia. The mean follow-up period was 27.8 months. The modified JOA score improved from 6.3 ± 1.6 to 9.5 ± 0.6. The local kyphosis angle was improved from 13.8 to 6.9° post-operatively, with insignificant loss of correction at the end of follow-up. Thirty-eight out of 40 patients had solid anterior fusion at the end of follow-up.

Conclusion

The clinical outcomes of this study showed that the transforaminal thoracic interbody approach is effective for both decompression and anterior reconstruction of the lower thoracic spine in patients with spondylodiscitis.

     

Lumbar hyperlordosis of neuromuscular origin: pathophysiology and surgical strategy for correction

Lumbar hyperlordosis of neuromuscular origin is rare and requires surgical treatment in order to preserve a good sitting posture. We report twenty-seven cases of a preponderantly sagittal hyperlordosis deformity of the lumbar spine in patients with neuromuscular disorders and identify the indications and results of treatment. Seventeen males and ten females, aged 13 to 27 years, underwent operations for a lumbar hyperlordosis of neuromuscular origin responsible for major difficulties in sitting. In all patients, the sacrum was horizontal and associated in twenty-six cases with marked pelvic anteversion. Eleven patients were treated surgically by a posterior approach. The sixteen remaining patients had a preliminary discectomy, followed by posterior correction and fusion. Lumbar hyperlordosis was reduced from 8 degrees to 77 degrees between L1 and S1. The horizontal sacrum was partially reduced with an improvement from 8 degrees to 50 degrees . Consequently, patients recovered a comfortable sitting position. One patient died of respiratory complications six weeks after surgery. Surgical correction is a demanding procedure which can be performed by a posterior approach. It is mandatory to analyse the spino-pelvic balance to avoid iliac retroversion and the loss of the role of the ischia in the sitting position.     

Lumbar Spine Degeneration and Flatback Deformity Alter Sitting-Standing Spinopelvic Mechanics—Implications for Total Hip Arthroplasty

BackgroundSpinal degeneration and lumbar flatback deformity can decrease recruitment of protective posterior pelvic tilt when sitting, leading to anterior impingement and increased instability. We aim at analyzing regional and global spinal alignment between sitting and standing to better understand the implications of spinal degeneration and flatback deformity for hip arthroplasty.MethodsSpinopelvic parameters of patients with full-body sitting-standing stereoradiographs were assessed: lumbar lordosis (LL), spinopelvic tilt (SPT), pelvic incidence minus LL (PI-LL), sagittal vertical axis (SVA), and T1 pelvic angle (TPA). Lumbar spines were classified as normal, degenerative (disc height loss >50%, facet arthropathy, or spondylolisthesis), or flatback (degenerative criteria and PI-LL >10°). Independent t-tests and analysis of variance were used to analyze alignment differences between groups.ResultsAfter propensity matching for age, sex, and hip osteoarthritis grade, 57 patients per group were included (62 ± 11 years, 58% female). Mean standing and sitting SPT, PI-LL, SVA, and TPA increased along the spectrum of disease severity. Increasing severity of disease was associated with decreasing standing and sitting LL. The flatback group demonstrated the greatest sitting SPT, PI-LL, SVA, and TPA. The amount of sitting-to-standing change in SPT, LL, PI-LL, SVA, and TPA decreased along the spectrum of disease severity.ConclusionSpinal degeneration and lumbar flatback deformity both significantly decrease lower lumbar spine mobility and posterior SPT from standing to sitting in a stepwise fashion. The demonstrated hypomobility in flatback patients likely serves as a pathomechanism for the previously observed increased risk of dislocation in total hip arthroplasty.     

A new lumbar fixation device alternative to pedicle-based stabilization for lumbar spine: In vitro cadaver investigation

Context: To evaluate the stability provided by a new bilateral fixation technique using an in vitro investigation for posterior lumbar segmental instrumentation.

Design: Experimental cadaver study. In this study, we propose an alternative technique for a posterior lumbar fixation technique called “inferior-oblique transdiscal fixation” (IOTF).

Setting: Study performed at Engineering Center for Orthopedic Research Exellence (ECORE) in Toledo University-Ohio.

Participants: Six human lumbar cadaveric specimen used in this study.

Interventions: In this study, we propose an alternative technique for a posterior lumbar fixation technique called “inferior-oblique transdiscal fixation” (IOTF). As a novel contribution to the classical technique, the entry point of the screw is the supero-lateral point of the intersecting line drawn between the corpus and the pedicle of the upper vertebra. This approach enables the fixation of two adjacent vertebrae using a single screw on each side without utilizing connecting rods.

Outcome Measures: Flexion (Flex), extension (Ext), right and left lateral bending (LB & RB), and right and left axial rotation (LR & RR), and the position data were captured at each load step using the Optotrak motion measurement system and compared for IOTF and posterior transpedicular stabilization.

Results: The Posterior stabilization system (PSS) and IOTF significantly reduced the ROM of L4-L5 segment compared to intact segment’s ROM. During axial rotation (AR) IOTF fused index segment more than PSS. Besides this, addition of transforaminal lumbar interbody fusion (TLIF) cage improved the stabilization of IOTF system during flexion, extension and lateral bending. Whereas, PSS yielded better fusion results during extension compared to IOTF with and without interbody fusion cages.

Conclusions: We hypothesized that the new posterior bilateral system would significantly decrease motion compared to the intact spine. This cadaver study showed that the proposed new posterior fusion technique IOTF fused the index segment in a similar fashion to the classical pedicle screw fusion technique.     

Osteotomies in proximal junctional kyphosis in the cervicothoracic area

Introduction

Proximal junctional kyphosis (PJK) of the cervicothoracic spine is a deformity that can affect patients who have undergone long thoracolumbar instrumented fusion. Preoperative hyperkyphosis of the thoracic spine and changes of more than 30° in lumbar lordosis are independent risk factors for the onset of PJK.

Methods

When PJK occurs in the cervicothoracic spine, extension of the fusion with eventual application of osteotomy techniques is frequently necessary to treat symptomatic patients or in case a neurological deficit occurs. Ponte osteotomy and pedicle subtraction osteotomy (PSO) are the two most used techniques to restore a good cervicothoracic alignment, although they are still demanding procedures even for expert surgeons. In junctional fractures, a vertebral column resection can be performed to support the anterior column. Ponte osteotomy ideally restores 10° at each treated level, while PSO allows a segmental correction up to 30°–35°. Adequate preoperative planning is fundamental for outlining the correct surgery and choosing the appropriate osteotomy.

Conclusions

The aim of corrective surgery is to restore the cervicothoracic alignment, obtaining an adequate postoperative sagittal balance and decreasing the risk of further complications and new revision surgeries.

     

Hidden blood loss during posterior spine fusion surgery

Background contextPosterior spine fusion is associated with significant intra- and postoperative blood losses. When referring to the total blood loss during spine surgery, the standard is to measure the intraoperative bleeding plus the postoperative drainage. This ignores the “hidden” blood loss that was found to be significant in other fields of surgery.PurposeThe purpose of this study was to examine whether posterior spine fusion carries a substantial hidden blood loss.Study design/settingA prospective study.Patient sampleWe prospectively studied 114 patients undergoing instrumented posterior spinal fusion at one center between January 2011 and April 2011.Outcome measuresTotal blood loss, visible blood loss, and hidden blood loss.MethodsFor each patient, the hidden blood loss was calculated by deducting the observed perioperative blood loss from the calculated total blood loss based on the hematocrit changes. We compared the percentage of the hidden blood loss out of the total blood loss for primary versus revision posterior spine fusion.ResultsPrimary decompression and posterior fusion patients had a mean total true loss of 1,439 mL. Their calculated hidden loss was 600 mL, 42% of the total loss. After revision posterior spinal fusion surgery, the mean total blood loss was 1,606 mL. The mean visible loss was 975 mL, and the mean hidden loss was 631 mL, 39% of the total loss. Thus, there was no statistical difference in the hidden blood loss between primary and revision posterior spinal fusion surgeries (p>.05). We did not find a significant difference in the percentage of the hidden blood loss between patients who underwent one, two, or three or more levels of surgery.ConclusionsAfter posterior spinal fusion, there may be a large amount of the hidden blood loss.     

经后路一次切除半椎体治疗先天脊柱畸形

目的　回顾性分析 9例由先天性半椎体造成的脊柱侧弯和后凸畸形经后路一次半椎体切除植骨固定矫正术的手术治疗效果。方法　 9例患者 ,半椎体的位置在胸腰段或腰椎 ,手术采用后路切口 ,切除半椎体后 ,内固定矫正畸形 ,植骨融合 ,术后平均随访时间为 2 0 .6月 ,术前、术后拍摄站立位的脊柱正侧位片。结果　所有患者均有不同程度的侧弯和后凸畸形 ,侧弯角由术前的 37.7°矫正至 10° ,后凸角由术前 30 .5°矫正至 6°,躯干位移从 2 3mm恢复至 5mm ,无任何手术并发症 ,无内固定断裂脱落 ,均融合。结论　此手术方法对发育前期的患儿且半椎体位于胸腰椎或腰椎造成的先天性脊柱畸形 ,是一有效、安全的方法。     

Stabilization of the collapsing spine in duchenne muscular dystrophy.

Of 41 patients with Duchenne muscular dystrophy, no ambulatory patient had scoliosis greater than 19 degrees. Non-ambulatory patients were prophylactically placed in body jackets, which kept the spine flexible and provided adequate support for sitting in the majority of patients. Ten patients had posterior spine fusion for progressive spinal collapse. The procedure was extensive with significant blood loss but boney fusion was achieved in every case. Pulmonary complications were minimized by performing preoperative tracheostomy on all patients who had vital capacities less than 40% and or non-functional coughs. Spinal fusion permitted long-term sitting stability despite the progression of the disease.     

Clinical and radiological outcomes after conservative treatment of TB spondylitis: is the 15 years’ follow-up in the MRC study long enough?

Introduction

Tuberculosis of the spine is a still a common disease entity, not only in developing countries but is also returning in developed countries especially in the immune-compromised patients. Conservative treatment with chemotherapy is still the main stay of treatment. This article focuses on the clinical and radiological outcomes, and problems with conservative treatment.

Method

The available literature of anti-tuberculosis chemotherapy in managing spinal tuberculosis was reviewed. Data sources included relevant literature of the English language identified through Medline search from 1946 to 2011. Personal experience and unpublished reviews from the authors’ institution were also included.

Results

Although majority of patients respond well to anti-tuberculosis chemotherapy, about 15 % of them develop paradoxical response. The Medical Research Council (MRC) studies have shown that for patients without significant neurological deficits, operative and conservative treatment could produce the same clinical outcome at 15 years follow-up. Patients treated operatively with debridement and spinal fusion with strut graft had faster bony fusion and less kyphotic deformity. In contrast, those treated with drugs alone or with simple debridement without fusion may result in disease reactivation, severe kyphosis or late instability, which in turn may lead to late-onset Pott’s paraplegia, back pain, sagittal imbalance and compromised pulmonary function that are difficult or risky to treat.

Conclusion

Recognition of the clinical and radiologic features of these late sequels is important for the management. Prevention of deformity in the early disease has been added to the modern standard of treatment of TB spine.

     

Pelvic parameters and global spine balance for spine degenerative disease: the importance of containing for the well being of content

Purpose

Spinal deformities and pathologies of the spinopelvic junction are conditions affecting up to 60–70 % of the general aging population. In this review, we discuss the more recent knowledge on sagittal balance and its clinical implications.

Methods

Review of the literature regarding global spine balance.

Results

Global spinal balance and its relationship to the pelvis correlate closely with disability and quality of life. It has been demonstrated that extensive surgery, previously considered to have poor balance between risks and outcomes, causes great improvements in health-related quality of life in the oldest age groups.

Conclusion

Failure to restore normal sagittal alignment in patients primarily operated for other than deformity results in unacceptable rates of poor results and revision surgery.

     

Nontraumatic posterior atlantooccipital dislocation associated with atlantoaxial instability

Introduction

Nontraumatic posterior atlantooccipital dislocation has only been rarely reported. In the current study, the authors reported an extremely rare case of nontraumatic posterior atlantooccipital dislocation associated with atlantoaxial instability.

Materials and methods

A 47-year-old female was referred with a history of neck pain for 5 years. The patient had no history of trauma. The axial rotation of range of motion of the cervical spine was severely restricted. Posterior atlantooccipital dislocation with atlantoaxial instability was confirmed through conventional radiography, computed tomography and magnetic resonance imaging. We performed realignment of the dislocation and posterior occipitocervical (C0–C2) fusion. After the surgery, the patient’s symptoms improved significantly and she manifested neurological improvement.

Conclusion

To our knowledge, this lesion has not been reported previously. Anomalies of upper cervical spine may have induced this instability.