Percutaneous vertebroplasty and balloon kyphoplasty in the treatment of osteoporotic vertebral fractures: a prospective randomized comparison.

PURPOSE: The purpose of this study is to compare the efficacy and safety of percutaneous vertebroplasty (PVP) and balloon kyphoplasty (BKP) in the treatment of osteoporotic vertebral compression fractures. MATERIALS AND METHODS: Patients with osteoporotic vertebral body fractures (T4-L5) were randomized and not blinded to kyphoplasty (n = 69) or vertebroplasty (n = 70). The postoperative pain score (VAS) at 12 months was the primary end point. The radiographic results were evaluated in relation to the resolution of the fracture and the possible onset of further osteoporotic fractures during follow-up. RESULTS: A total of one hundred and thirty-nine patients were eligible for randomization (n = 70 for PVP group and n = 69 for BKP), and twenty-six patients (twenty in the BKP group and six in the PVP group) were excluded. The mean average age of patients was 73 years, and 82% of the patients were females. VAS pain score was significantly reduced after surgery in both groups, and there were no significant differences between the two groups in postoperative VAS score. There was a significant reduction in kyphotic wedge angle and improvement of the sagittal index in both groups, but there was no significant difference between the two groups. There was a significant higher risk incidence of adjacent level fractures in the vertebroplasty group. CONCLUSIONS: In terms of clinical outcomes, there were no differences between the two groups. Both showed a significant clinical improvement, vertebral body height restoration and reduction in the kyphotic angle. There was a significant higher risk of adjacent level fractures in the vertebroplasty group.

Surgical treatment of spinal disorders in Parkinson's disease.

PURPOSE: Most patients suffering from Parkinson's disease (PD) exhibit alterations in the posture, which can in several cases give rise to spine deformities, both in the sagittal and the coronal plane. In addition, degenerative disorders of the spine frequently associated to PD, such as spinal stenosis and sagittal instability, can further impact the quality of life of the patient. In recent years, spine surgery has been increasingly performed, with mixed results. The aim of this narrative review is to analyze the spinal disorders associated to PD, and the current evidence about their surgical treatment. METHODS: Narrative review. RESULTS: Camptocormia, i.e., a pronounced flexible forward bending of the trunk with 7% prevalence, is the most reported sagittal disorder of the spine. Pisa syndrome and scoliosis are both common and frequently associated. Disorders to the spinopelvic alignment were not widely investigated, but a tendency toward a lower ability of PD patients to compensate the sagittal malalignment with respect to non-PD elderly subjects with imbalance seems to emerge. Spine surgery in PD patients showed high rates of complications and re-operations. CONCLUSIONS: Disorders of the posture and spinal alignment, both in the sagittal and in the coronal planes, are common in PD patients, and have a major impact on the quality of life. Outcomes of spine surgery are generally not satisfactory, likely mostly due to muscle dystonia and poor bone quality. Knowledge in this field needs to be consolidated by further clinical and basic science studies. These slides can be retrieved under Electronic Supplementary Material.

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.

Variations of cervical lordosis and head alignment after pedicle subtraction osteotomy surgery for sagittal imbalance.

INTRODUCTION: The variations of the cervical lordosis after correction of sagittal imbalance have been poorly studied. The aim of our study is to verify whether the cervical lordosis changes after surgery for sagittal imbalance. MATERIALS AND METHODS: Thirty-nine patients were included in the study. Cervical, thoracic and lumbar spine, pelvic and lower-limb sagittal parameters were recorded. The cranial alignment was measured by the newly described Cranial Slope. RESULTS: The global cervical kyphosis (preop -43°, postop -31.5°) and the upper (preop -24.1°, postop -20.2°) and lower cervical kyphosis (preop -18.1°, postop -9.2°) were significantly reduced after surgical realignment of the trunk. A positive linear correlation was observed between the changes in T1 slope and the lower cervical lordosis, and between T1 slope and the global cervical alignment. CONCLUSIONS: The cervical lordosis is reduced by surgical correction of malalignment of the trunk, suggesting an adaptive role to maintain the head's neutral position.

Spinal osteotomies to treat post-traumatic thoracolumbar deformity.

Fractures of the thoracolumbar junction can lead to regional kyphosis, this being a significant cause of pain and disability for the patients. After a traumatic fracture of the thoracolumbar spine, early or late regional kyphosis can be observed. This post-traumatic deformity can, however, be corrected with appropriate surgical methods. Posterior tricolumnar osteotomies are some of the most powerful methods of correction and are particularly indicated when sagittal and coronal deformities have to be simultaneously corrected or when anterior surgery is not possible. Anterior corpectomy and lengthening with posterior instrumentation are, however, an alternative technique to restore the anterior column support and to correct the regional kyphotic deformity and an option for appropriate sagittal balance restoration and control of symptoms. Proper surgical technique, evaluation of the bone quality and identification of eventual extension of the deformity to the thoracic spine are key aspects in prevention of failures.

Standing lateral lumbar spine and pelvis (SLLP) radiograph: a screening, reduced radiation method, for sagittal imbalance.

INTRODUCTION: Sagittal imbalance is a predictor of failure after surgery for lumbar degenerative pathology. For this reason, specialists advocate correction of sagittal deformity and systematically perform preoperative standing whole spine films. Such diagnostic investigations expose patients to significant doses of radiation. The authors propose an easier radiographic investigation helpful as a screening test to identify patients likely to have sagittal imbalance. METHODS: Fifteen whole spine lateral films were evaluated, classifying subjects into three categories: balanced, compensating imbalanced or imbalanced. A second specialist evaluated the reduced SLLP versions of the film (from L1 to proximal femora), measuring spinopelvic parameters. RESULTS: In the SLLP film, the combination of two parameters (femoral inclination >10°, pelvic tilt >1/3 pelvic incidence +5°) identified 94 % of patients with altered sagittal balance. CONCLUSIONS: This study preliminarily suggests that the SLLP film can be a useful screening test for sagittal balance abnormalities.

Failures and revisions in surgery for sagittal imbalance: analysis of factors influencing failure.

INTRODUCTION: Sagittal imbalance is an important risk factor for spinal disability, pain and loss of health related quality of life. Its correction has a positive impact on these outcomes. Still, it is a very aggressive surgery, with a high revision rate. The aim of this study is to analyze the most important causes of failure of surgery for correction of sagittal imbalance. DESIGN AND METHODS: In this retrospective observational cohort study twelve patients who previously underwent surgery for sagittal imbalance correction were revised in the period 2009-10. We analyzed angular parameters of sagittal balance before and after primary surgery, type of instrumentation, modality of fusion, implant density, instrumented levels, modality of failure, time from first surgery and angular parameters after revision. RESULTS AND CONCLUSION: Causes of failure were insufficient correction, junctional kyphosis, screw loosening and pseudoarthrosis with rod breakage. In every case, patients presented a new onset or a worsening of sagittal imbalance and pain.

Preoperative calculation of the necessary correction in sagittal imbalance surgery: validation of three predictive methods.

INTRODUCTION: Surgery for correction of sagittal imbalance has frequent adverse events and complications. The most frequent cause of failure is inadequate correction of imbalance. The aim of this study is to verify the accuracy of three published methods (exact method by Ondra, FBI method by Le Huec and spinofemoral angle method by Lamartina) to preoperatively calculate the needed correction. DESIGN: This is a retrospective cohort study. METHODS: Fifteen patients treated for correction of sagittal imbalance, with preoperative and postoperative lateral standing whole spine radiographs, were identified. Preoperative calculation of the amount of needed correction has been done using these methods. In postoperative X-rays, the amount of correction obtained with and the degree of correction of sagittal imbalance have been measured. RESULTS AND DISCUSSION: The FBI and SFA methods obtain equivalent calculations of the amount of needed correction. The estimated correction angle with both methods is higher than that calculated with the exact trigonometric method. The difference between the latter and the former methods is equivalent to the observed excess of pelvic tilt.

Molecular MR imaging for the evaluation of the effect of dynamic stabilization on lumbar intervertebral discs.

The dynamic stabilization of lumbar spine is a non-fusion stabilization system that unloads the disc without the complete loss of motion at the treated motion segment. Clinical outcomes are promising but still not definitive, and the long-term effect on instrumented and adjacent levels is still a matter of discussion. Several experiments have been devised in order to gain a better understanding of the effect of the device on the intervertebral disc. One of the hypotheses was that while instrumented levels are partially relieved from loading, adjacent levels suffer from the increased stress. But this has not been proved yet. The aim of this study was to investigate the long-term effect of dynamic stabilization in vivo, through the quantification of glycosaminoglycans (GAG) concentration within instrumented and adjacent levels by means of the delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) protocol. Ten patients with low back pain, unresponsive to conservative treatment and scheduled for Dynesys implantation at one to three lumbar spine levels, underwent the dGEMRIC protocol to quantify GAG concentration before and 6 months after surgery. Each patient was also evaluated with visual analog scale (VAS), Oswestry, Prolo, Modic and Pfirrmann scales, both at pre-surgery and at follow-up. Six months after implantation, VAS, Prolo and Oswestry scales had improved in all patients. Pfirrmann scale could not detect any change, while dGEMRIC data already showed a general improvement in the instrumented levels: GAG was increased in 61% of the instrumented levels, while 68% of the non-instrumented levels showed a decrease in GAG, mainly in the posterior disc portion. In particular, seriously GAG-depleted discs seemed to have the greatest benefit from the Dynesys implantation, whereas less degenerated discs underwent a GAG depletion. dGEMRIC was able to visualize changes in both instrumented and non-instrumented levels. Our results suggest that the dynamic stabilization of lumbar spine is able to stop and partially reverse the disc degeneration, especially in seriously degenerated discs, while incrementing the stress on the adjacent levels, where it induces a matrix suffering and an early degeneration.

What comprises a good outcome in spinal surgery? A preliminary survey among spine surgeons of the SSE and European spine patients.

Standardized and validated self-administered outcome-instruments are broadly used in spinal surgery. Despite a plethora of articles on outcome research, no systematic evaluation is available on what actually comprises a good outcome in spinal surgery from the patients' and surgeons' perspective, respectively. However, this is a prerequisite for improving outcome instruments. In performing a cross-sectional survey among spine patients from different European regions and spine surgeons of the SSE, the study attempted (1) to identify the most important domains determining a good outcome from a patients' as well as a surgeon's perspective, and (2) to explore regional differences in the identified domains. For this purpose, a structured interview was performed among 30 spine surgeons of the SSE and 353 spine surgery patients (representing Northern, Central and Southern Europe) to investigate their criteria for a good outcome. A qualitative and descriptive approach was used to evaluate the data. Results revealed a high agreement on what comprises a good outcome among surgeons and patients, respectively. The main parameters determining good outcome were achieving the patients' expectations/satisfaction, pain relief, improvement of disability and social reintegration. Younger patients more often expected a complete pain relief, an improved work capacity, and better social life participation. Patients in southern Europe more often wanted to improve work capacity compared to those from central and northern European countries. No substantial differences were found when patients' and surgeons' perspective were compared. However, age and differences in national social security and health care system ("black flags") have an impact on what is considered a good outcome in spinal surgery.

Computer-assisted tomography of scoliosis operated with or without Harrington's rod. Biomechanics aspects of the fusion.

Forty-eight cases of posterior vertebral arthrodesis for scoliosis, performed with or without instrumentation, were examined using computed tomography (CT) scanning to study the evolving fusion mass. The authors observed that the fusion mass area is more voluminous in the cases performed without instrumentation than in the ones performed with instrumentation, and that 2 years after fusion the bone mass shows already a considerable increase. For the cases operated with Harrington's technique, the increase of the fusion mass is very slow and becomes considerable 5 years after operation. In both series, the section of the fusion masses at the apex of the curve is asymmetric (with prevalence on the concave side), with an area of central resorption that shows the structure of a long bone (box section).

Posterior spinal fusion in scoliosis: computer-assisted tomography and biomechanics of the fusion mass.

Thirty patients who had posterior vertebral fusion for scoliosis, performed without metallic implants, were examined using computer-assisted tomography to study the configuration of the evolving fusion mass. It was observed that the deposition of bone followed lines of force, according to Wolff's Law. The greatest amounts of bone at the apex of the curve on the concave side indicate that flexion-compression forces are greater at this point. Further, it was observed that usually the fusion mass, seen in section, has a hollow "box-section" shape, which means that a resorption of unstressed central bone occurs. The hypothesis that the torsional forces are the predominant forces acting on the scoliotic spine can explain the characteristic "box-section" of the CT scans obtained.