Residual kyphotic deformity is considered the main factor for the increased risk of new fractures after an osteoporotic vertebral fracture. We hypothesized that even in the absence of kyphotic deformity, the altered pressure profile of the disc after a fracture will increase the risk for subsequent fractures.

Materials and Methods: Six fresh-frozen, human thoracolumbar specimens, consisting of 5 adjacent vertebrae, were used. A void was randomly created under the upper (n=3) or the lower (n=3) endplate of the middle vertebra. The specimen was then compressed in flexion until a selective fracture of the weakened endplate was observed. Vertebral kyphosis was reduced with extension. After cementation of the fracture, the rest of the trabecular content was evacuated and was filled with cement. Specimens were tested in flexion-extension (±6Nm) under 400N preload before and after the index fracture. Pressure was recorded at the discs above and below the fractured VB and strain at the anterior wall of the adjacent VBs. Finally, the specimen was loaded in flexion until a subsequent fracture was observed on fluoroscopy.

Results: In the intact specimens, nucleus pressure increased by 26.4±13.9% in full flexion compared to neutral posture. After the index fracture, the pressure in full flexion increased by 15.2±11 % in the discs with unfractured endplates, but decreased by 19±26.7% in the discs with the fractured endplate (p< 0.05). Anterior wall strain at the VB adjacent to the fractured endplate increased by 94.2%±22.8% (p=0.02), compared to an 18.2%±7.1% (p=0.98) increase at the VB adjacent to the unfractured endplate. Subsequent loading of the specimens after cementation of the index fracture resulted in a fracture of the adjacent VB close to the fractured endplate of the middle vertebra in 4 specimens and at the upper potted VB in one specimen. Maximum load applied with the actuators failed to create a fracture in one specimen.

Discussion: The effects of the fractured endplate were isolated by eliminating other known parameters. Vertebral kyphosis was reduced and cement was similarly distributed under both endplates.

In the intact specimens, nucleus pressure gradually increased during flexion. This can more evenly distribute the load during flexion to the entire surface of the endplate and avoid excessive load concentration to the anterior portion. After an endplate fracture, the nucleus pressure gradually decreased during flexion, meaning that the anterior annulus was forced to bear more load. This uneven load transfer to the anterior part of the VB resulted in doubling the strain at the VB adjacent to the fractured end plate. All adjacent factures were observed at the vertebra next to the damaged endplate. The altered mechanical behavior of the nucleus can be ascribed to the increased available space after the endplate depression.

The circulatory effects of multilevel balloon kyphoplasty (BK) are not adequately addressed, neither the effectiveness of egg shell cementoplasty in preventing anticipated cement leakage in difficult cases. The purpose of this study was to evaluate

the effect of multilevel BK to blood pressure and arterial blood gasses;

Materials and methods: This is a prospective study of 89 patients (215 vertebral bodies-VBs) with osteoporotic compressive fractures (OCF), and 27 with osteolytic tumors (OT) (88 VBs). The mean age was 67.6 years. 27 patients with OCF were treated at one level, 26 at two, 21 at three, 7 at four, 6 at five, and 2 at six levels at the same sitting. Three patients with OT were treated at one level, 6 at two, 9 at three, 3 at four, 4 at five, and 2 at seven. Egg shell balloon cementoplasty to prevent cement leakage was performed in 10 patients with severe endplate fracture or vertebral wall lytic destruction. Arterial blood pressure and oxygen saturation were monitored during surgery. Arterial blood gases were measured before and 3 min after cement injection. Cement leakage was assessed by the postoperative x rays and computer tomography scans.

Results: A drop in blood pressure of more than 25mmHg during cement injection was observed in 6 patients, and was not associated with the number of VB treated. Blood pressure was dropped more than 40mm in 2 patients and the procedure was aborted after completing 1 level in the first and 2 levels in the second. Drop in arterial O2 saturation was noted in 4 patients. One patient treated for 5 levels developed fever and tachepnoea for 24 hours after surgery. Arterial O2 and chest x-rays were normal. Cement leakage was found in 9.7% (21/215) of VBs treated for OCF. Its incidence per location was: epidural, 0.9% (2 VBs); intraforaminal, 0.5% (1 VB); intradiscal, 3.2% (7 VBs); and through anterior or lateral walls, 5.1% (11 VBs). In the OT group cement leakage was found in 10.2% (9/88) of the treated VBs. Its location included 8 (9%) through the anterior or lateral walls and one (1.1%) intradiscal. Cement leakage had no clinical consequences. No cement leakage was observed in cases treated with egg shell balloon cementoplasty.

Conclusions: BK is a safe procedure when applied for multiple levels in the same sitting, and its rare circulatory effects are not related to the number of levels treated. The incidence of cement leakage in this study was 10%, which is far less than that reported with vertebroplasty using routine postoperative CT scan. Egg shell balloon cementoplasty can effectively minimize cement leakage in cases with fractured endplate or lytic destruction of VB walls.

Purpose: The purpose of this study is to evaluate the safety of methylmethacrylate cement balloon kypho-plasty (BK) when applied to five or six levels in the same sitting and the incidence and location of cement leakage.

Methods: Eighty nine patients (215 vertebral bodies-VBs) with osteoporotic compressive fractures (OCF), and 24 with osteolytic tumors (OT) (72 VBs) were treated with BK. Of patients with OCF, 27 were treated at one level, 26 at two, 21 at three, 7 at four, 6 at five, 2 at six levels. Of OT patients, 3 were treated at one level, 5 at two, 9 at three, 3 at four, and 4 at five.

Results: A drop in blood pressure of more than 25mmHg during cement injection was observed in four patients, and was not associated with the number of VB treated. The procedure was aborted in two patients. Otherwise no significant drop in arterial O2 was noted. One patient treated for 5 levels developed fever and tachepnoea for 24 hours after surgery. Arterial O2 and chest x-rays were normal. Pain significantly improved in 95% of patients with OCF and 98% of patients with tumors. In the osteoporotic group, kyphosis correction was achieved in 91% with a mean correction of 7.89°. Cement leakage occurred in 21/215 VBs (9.7%); Epidural: two (0.9%), intraforaminal: 1 (0.5%), intradiscal: 7 (3.2%) while through the anterior or lateral vertebral wall: 11 (5.1%). In the OT group leakage occurred in 6 VBs (8.3%), including 9 (7.0%) through the anterior or lateral wall and one (1.3%) intradiscal. None of the patients had any clinical consequences associated with cement leakage.

Conclusions: BK is a safe and effective procedure, even when applied for 5 or 6 levels. End plate fracture or vertebral wall lytic destruction can effectively be managed by eggshell balloon cementoplasty, thus minimizing the incidence of cement leakage. The incidence of cement leakage with KP (9.8%) is far less than that reported with vertebroplasty, (65.5% shown on CT scans).

Introduction The unacceptably low fusion rate with stand-alone ALIF cages led to the practice of combining ALIF with posterior instrumentation. Recently ALIF combined with anterior lumbar plate fixation has been promoted to obviate the need for additional posterior surgery. The purpose of this study is to compare the multidirectional flexibility of ALIF combined with posterior instrumentation (either translaminar facet screws or pedicle screws) to that combined with anterior plate fixation.

Methods Ten human lumbar cadaveric motion segments were tested in the following sequence: (i) intact, (ii) stand alone ALIF cages, (iii) ALIF and anterior lumbar plate, (iv) ALIF with translaminar facet screws, (v) ALIF with pedicle screws. In each condition, the specimens were tested under bending moments of 0–8 Nm flexion, 0–6 Nm extension, 0–6 Nm lateral bending and 0–5 Nm axial rotation. 3D motions were measured using an optoelectronic motion monitoring system.

Results The ALIF cages decreased the ROM in the sagittal and frontal planes (p< 0.05). Their effectiveness improved in the sagittal plane with the combination of either anterior plate or posterior fixation (p< 0.05). There was no statistical difference between the ALIF/ Plate and translaminar screws or pedicle screws in flexion-extension and axial rotation ROM. There was a difference in the lateral bending ROM between the ALIF with anterior plate and ALIF with either translaminar facet screws or ALIF with pedicle screws (p< 0.05) favouring posterior fixation. However there was no statistical difference between the combined ROM for ALIF/Plate and translaminar screws or pedicle screws.

Discussion This study shows that the stability achieved with the combination of ALIF with an anterior plate is comparable to that achieved with posterior instrumentation with translaminar facet screws or pedicle screws. This suggests that sufficient segmental stability may be provided by anterior plating, obviating the need for a concomitant posterior approach.

Aim: Presentation of the application of the transcervical system of posterior spinal fusion Varigrip in spinal infections showing its rapid and safe application and also its stability to the spinal level where it is applied to.

Patients and Methods: 22 patients (13 men / 9 women) with mean age 50, 6 years (18–79) and mean follow up time is 34,6 months (9–62) were included in our study. In 10 patients the level was in lumbar spine and in 12 in thoracic spine. In their admission 16 patients had neurological deficit and 22 mean pain score according to VAS 8, 4 (6–10). ESR was increased in 14 patients, CRP in 20 and 7 patients had also increased WBC. All 22 patients had increased signal of Tc” and 69Ga in the level of the lesion and also pathological signal in MRI (Tl, T2 and Tl with Gadolinium). All the patients underwent posterior spinal fusion using Varigrip system and 17 of these underwent in the same time somatectomy and anterior fusion.

Results: Pathologic organism was isolated to all the patients. In 20 patients the tissue culture of the lesion isolated the pathologic organism and the other 2 patients came to us with positive blood cultures from other hospitals. 6 months postoperatively 21 patients referred pain score according to VAS 2,4 (1–4) and 1 patient had no improvement (5–7). 1 patient died of PE, another of chest infection and one of head injury. 1 patient had recurrence of the infection in another level, 1 had herpeszoster and 1 had infection of the surgical wound. All the patients had neurological improvement postoperatively.

Conclusions: The method is characterized as safe because of avoidance of the neurological structures. It can be applied also safely to patients with osteoporosis. Its application is rapid so the surgical time is minimum and also it doesn’t need image intensifier during the surgical procedure. It can be applied easily either in thoracic or lumbar spine and it provides stability of the spine.