European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
-
Review Comparative Study
Biomechanical analysis of the spino-pelvic organization and adaptation in pathology.
Standing in an erect position is a human property. The pelvis anatomy and position, defined by the pelvis incidence, interact with the spinal organization in shape and position to regulate the sagittal balance between both the spine and pelvis. Sagittal balance of the human body may be defined by a setting of different parameters such as (a) pelvic parameters: pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS); (b) C7 positioning: spino-pelvic angle (SSA) and C7 plumb line; (c) shape of the spine: lumbar lordosis. ⋯ The genuine shape of the spine is probably one of the main mechanical factors of degenerative evolution. This shape is oriented by a shape pelvis parameter, the pelvis incidence. In case of pathology, this constant parameter is the only signature to determine the original spine shape we have to restore the balance of the patient.
-
In L5-S1 spondylolisthesis, it has been clearly demonstrated over the past decade that sacro-pelvic morphology is abnormal and that it can be associated to an abnormal sacro-pelvic orientation as well as to a disturbed global sagittal balance of the spine. The purpose of this article is to review the work done within the Spinal Deformity Study Group (SDSG) over the past decade, which has led to a classification incorporating this recent knowledge. ⋯ The clinical relevance is that clinicians need to keep in mind when planning treatment that subjects with L5-S1 spondylolisthesis are a heterogeneous group with various adaptations of their posture. In the current controversy on whether high-grade deformities should or should not be reduced, it is suggested that reduction techniques should preferably be used in subjects with evidence of abnormal posture, in order to restore global spino-pelvic balance and improve the biomechanical environment for fusion.
-
Comparative Study Clinical Trial
Sagittal balance parameters influence indications for lumbar disc arthroplasty or ALIF.
Chronic lower back pain is a potentially incapacitating condition associated with disc degeneration. Although therapy is primarily pharmaceutical, surgery comprising arthrodesis constitutes an alternative. Anterior intersomatic lumbar arthrodesis (ALIF, anterior interbody lumbar fusion) is the reference approach, although total disc arthroplasty may also be undertaken. Analysis of pelvic and spinal parameters provides the best indication of sagittal balance. ⋯ The pre-operative SSA value for the study population was 126.09° ± 8.45° and the mean spine tilt angle was 90° compared with 95° in healthy subjects. Following surgery, the SSA was considerably increased in the discal arthroplasty, resulting in a significantly more balanced spinal position. In the group of patients undergoing arthrodesis using the ALIF technique, no such significant improvement was found despite the use of a lordosis cage. We showed that in cases of low pelvic incidence, it was necessary to maintain a Roussouly type 1 or 2 back without increasing lordosis. The results demonstrated the value of L4-L5 disc prostheses in these subjects. L5-S1 arthrodesis seemed a more suitable approach for treating patients with elevated sacral slope (back type 3 or 4). This new type of analysis of sagittal parameters should be performed prior to all surgical procedures involving lumbar prostheses.
-
Comparative Study
Comparison of Nurick grading system and modified Japanese Orthopaedic Association scoring system in evaluation of patients with cervical spondylotic myelopathy.
The purpose of this study was to determine the correlation between Nurick grade and modified Japanese Orthopaedic Association (mJOA) scores in the preoperative and postoperative follow-up evaluation of patients with cervical spondylotic myelopathy (CSM). This retrospective study included 93 patients with CSM who underwent central corpectomy (CC) between 1998 and 2008. Preoperative and postoperative Nurick grade and total mJOA (tmJOA) and lower limb mJOA (llmJOA) score of each patient was documented and the correlation between the Nurick grades and the mJOA scores was studied. ⋯ Although Nurick grade and llmJOA had good correlation preoperatively, at follow-up evaluation after surgery, there was disagreement in 11.8% (11/93) patients. One of the major reasons for the discrepancy between the Nurick scale and the llmJOA at follow-up evaluation was the ability of patients to regain employment without an improvement in the llmJOA score. As disease-specific scales, both Nurick scale and mJOA score should be utilized in the evaluation of patients with CSM.