Lumbar lordotic correction (LLC), the gold standard treatment for sagittal spinal malalignment (SMA), and its effect on sagittal balance have been critically discussed in recent studies. This paper assesses the biomechanical response of the spinal components to LLC as an additional factor for the evaluation of LLC. Human lumbar spines (L2L5) were loaded with combined bending moments in flexion (Flex)/extension (Ex) or lateral bending (LatBend) and axial rotation (AxRot) in a physiological environment. We examined the dependency of AxRot range of motion (RoM) on the applied bending moment. The results were used to validate a finite element (FE) model of the lumbar spine. With this model, the biomechanical response of the intervertebral discs (IVD) and facet joints under daily motion was studied for different sagittal alignment postures, simulated by a motion in Flex/Ex direction. Applied bending moments decreased AxRot RoM significantly (all P < 0.001). A stronger decline of AxRot RoM for Ex than for Flex direction was observed (all P < 0.0001). Our simulated results largely agreed with the experimental data (all R2 > 0.79). During the daily motion, the IVD was loaded higher with increasing lumbar lordosis (LL) for all evaluated values at L2L3 and L3L4 and posterior annulus stress (AS) at L4L5 (all P < 0.0476). The results of this study indicate that LLC with large extensions of LL may not always be advantageous regarding the biomechanical loading of the IVD. This finding may be used to improve the planning process of LLC treatments.
Vertebral osteomyelitis (VO) is a primary infection of the endplates of the vertebral bodies with secondary infection of the adjacent intervertebral discs. Diagnosis is often delayed due to unspecific symptoms and a lack of specific infection markers. In this prospective study, we determined the suitability of 27 cytokines for the discrimination of VO and degenerative diseases of the spine and compared its diagnostic potential in relation to the C-reactive protein (CRP), which is widely used as a non-specific inflammation marker in clinical diagnostics. The patients included in this study underwent surgical stabilization of the lumbar and/or thoracic spine with removal of 1 or more affected intervertebral discs, as therapy for VO (n = 16) or for erosive osteochondrosis (EO, control group, n = 20). We evaluated the cytokine and CRP concentrations before (pre-OP = -20-0d where 0 means the day of surgery) and after surgery (post-OP) on days 3-5, 6-11, 40-56, and 63-142. Compared to the control patients pre-OP, a significantly higher elevation of the 4 cytokines IL-6, IL-8, IL-12 (p70), and VEGF as well as CRP were found in the VO patients, showing an area under the curve > 0.80 pre-OP. No significant differences were observed between VO patients with high and low virulent bacteria with respect to all 5 elevated biomarkers. This is the first prospective study in which a broad spectrum of 27 cytokines was analysed via multiplex assay using sera from patients with and without VO. Our results show that, in addition to CRP, 4 different cytokines were significantly altered in VO but not control patients. The results implicate that these candidate cytokines may be used in a multiplex assay for discrimination between VO and degenerative diseases of the spine.
Background: Interspinous stand-alone implants are inserted without open decompression to treat symptomatic lumbar spinal stenosis (LSS). The insertion procedure is technically simple, low-risk, and quick. However, the question remains whether the resulting clinical outcomes compare with those of microsurgical decompression, the gold standard.
Despite proven advantages, pulsatile lavage seems to be used infrequently during preparation in cemented total knee arthroplasty. This remains irritating, as the technique has been suggested to improve radiological survival in cemented TKA, where aseptic loosening of the tibial component represents the main reason for revision. Furthermore, there may be a potential improvement of fixation strength for the tibial tray achieved by increased cement penetration. In this study, the influence of pulsed lavage on mechanical stability of the tibial component and bone cement penetration was analyzed in a cadaveric setting. Six pairs of cadaveric, proximal tibia specimen underwent computed tomography (CT) for assessment of bone mineral density (BMD) and exclusion of osseous lesions. Following surgical preparation, in one side of a pair, the tibial surface was irrigated using 1800ml normal saline and pulsatile lavage, while in the other side syringe lavage using the identical amount of fluid was applied. After careful drying, bone cement was hand-pressurized on the bone surface, tibial components were inserted and impacted in an identical way. After curing of cement, specimen underwent a postimplantation CT analysis). Cement distrubution was then assessed using a three-dimenionsional visualization software. Trabecular bone, cement and implant were segmented based on an automatic thresholding algorithm, which had been validated in a previous study. This allowed to determine median cement penetration for the entire cemented area. Furthermore, fixation strength of the tibial trays was determined by a vertical pull-out test using a servohydraulic material testing machine. Testing was performed under displacement control at a rate of 0,5mm/sec until implant failure. Data was described by median and range. Results were compared by a Wilcoxon matched pairs signed rank test with a type 1 error probability of 5 %. Median pull-out forces in the pulsed lavage group were 1275N (range 864–1391) and 568N (range 243–683) in the syringe lavage group (p=0.031). Cement penetration was likewise increased (p=0.031) in the pulsed lavage group (1.32mm; range 0.86–1.94), when compared to the syringe irrigated group (0.79mm; range 0.51–1.66). Failure occurred in the pulsatile lavage group at the implant-cement interface and in the syringe lavage group at the bone-cement interface, which indicates the weakness of the latter. Altogether, improved mechanical stability of the tibial implant and likewise increased bone cement interdigitation could be demonstrated in the current study, when pulsed lavage is implemented. Enhanced fixation strength was suggested being a key to improved survival of the implant. If this is the case, pulsatile lavage should be considered being a mandatory preparation step when cementing tibial components in TKA.
The authors present what appears to be the first case of congenital kyphosis due to a T12 hemivertebra in a four-year-old boy with endochondral gigantism syndrome of unknown origin. Because of his overgrowth, the patient had severe medical and orthopaedic problems and was almost immobile. Prior to surgery, he experienced a rapidly progressive thoracolumbar kyphosis to 600 (T10-L2). MRI of the brain and spine showed critical protraction of the spinal cord and myelopathy from compression at T12. Single-stage posterior resection of the hemivertebra with spinal shortening and dorsal transpedicular instrumentation of T10-L2 was performed. Although the bone tissue was cartilaginous and dysplastic, 420 (30%) correction was achieved along with decompression of the spinal canal. The patient experienced no neurological impairment post-operatively. At follow-up examination 1.5 year after surgery, the patient's movement disorder had improved markedly and he was able to stand and walk. This very rare case demonstrates that single-stage posterior hemivertebra resection and transpedicular instrumentation for correction of congenital kyphosis can be a safe and effective procedure even in a very challenging case.
Powerlifting is a discipline of competitive weightlifting. To date, no investigations have focused on pain encountered during routine training. The aim of the study was to identify such pain, assign it to particular exercises and assess the data regarding injuries as well as the influence of intrinsic and extrinsic factors. Data of 245 competitive and elite powerlifters was collected by questionnaire. Information regarding current workout routines and retrospective injury data was collected. Study subjects were selected from 97 incorporated powerlifting clubs. A percentage of 43.3% of powerlifters complained of problems during routine workouts. Injury rate was calculated as 0.3 injuries per lifter per year (1 000 h of training=1 injury). There was no evidence that intrinsic or extrinsic factors affected this rate. Most commonly injured body regions were the shoulder, lower back and the knee. The use of weight belts increased the injury rate of the lumbar spine. Rate of injury to the upper extremities was significantly increased based on age >40 years (shoulder/p=0.003, elbow/p=0.003, hand+wrist/p=0.024) and female gender (hand+wrist/p=0.045). The daily workout of a large proportion of powerlifters is affected by disorders which do not require an interruption of training. The injury rate is low compared to other sports.
The purpose of this study was to assess the radiological and clinical outcome parameters following lumbar hybrid dynamic instrumentation with the focus on the adjacent segment degeneration (ASD) and adjacent segment disease (ASDi). In this prospective trial all patients presenting with degenerative changes to the lumbar spine have been included. Precondition was a stable adjacent level with/without degenerative alteration. The elected patients underwent a standardised fusion procedure with hybrid instrumentation (DTO™, Zimmer Spine Inc., Denver, USA). Patients' demographics have been documented and the follow-up visits were conducted after 6 weeks, and then stepwise after 6 up to 48 months. Each follow-up visit included assessment of quality of life and pain using specific questionnaires (COMI, SF-36, ODI) and the radiological evaluation with focus on the adjacent level alterations. At a mean follow up of 24 months an incidence of ASD with 10.91% and for ASDi with 18.18% has been observed. In 9% a conversion to standardised fusion was needed. There was a high rate of mechanical complication: (1) screw loosening (52.73%), (2) pedicle screw breakage (10.91%), and (3) rod breakage (3.64%) after a follow up of a maximum of 60 months. There were no significant difference of COMI, ODI and SF-36(v2) in comparison to all groups but all 55 patients showed a clinical improvement over the time. The dynamic hybrid DTO™ device is comparable to the long-term results after standardised fusion procedure, while a high rate of mechanical complication decreased the initial benefit. This trial was registered at the ClinicalTrials Register ( #NCT03404232 , 2018/01/18, registered retrospectively).
