Aims

We aimed to retrospectively assess the accuracy and safety of CT navigated pedicle screws and to compare accuracy in the cervical and thoracic spine (C2-T8) with (COMB) and without (POST) prior anterior surgery (anterior cervical discectomy or corpectomy and fusion with ventral plating: ACDF/ACCF).

Aims. Loosening of pedicle screws is a major complication of posterior spinal stabilisation, especially in the osteoporotic spine. Our aim was to evaluate the effect of cement augmentation compared with extended dorsal instrumentation on the stability of posterior spinal fixation. Materials and Methods. A total of 12 osteoporotic human cadaveric spines (T11-L3) were randomised by bone mineral density into two groups and instrumented with pedicle screws: group I (SHORT) separated T12 or L2 and group II (EXTENDED) specimen consisting of T11/12 to L2/3. Screws were augmented with cement unilaterally in each vertebra. Fatigue testing was performed using a cranial-caudal sinusoidal, cyclic (1.0 Hz) load with stepwise increasing peak force. Results. Augmentation showed no significant increase in the mean cycles to failure and fatigue force (SHORT p = 0.067; EXTENDED p = 0.239). Extending the instrumentation resulted in a significantly increased number of cycles to failure and a significantly higher fatigue force compared with the SHORT instrumentation (EXTENDED non-augmented + 76%, p < 0.001; EXTENDED augmented + 87%, p < 0.001). Conclusion. The stabilising effect of cement augmentation of pedicle screws might not be as beneficial as expected from biomechanical pull-out tests. Lengthening the dorsal instrumentation results in a much higher increase of stability during fatigue testing in the osteoporotic spine compared with cement augmentation. Cite this article: Bone Joint J 2016;98-B:1099–1105

Revision surgery and surgery in previously operated areas are associated with an increased infection risk. In such situations, aggressive surgical debridement may be necessary to control and eradicate the infection. Full thickness defects resulting from such debridement present as a challenge. In most cases, an association of various methods, both surgical and non-surgical, is necessary. Our goal is to describe the use of vaccum dressings as an effective way to deal with extensive and infected dorsolumbar surgical defects, while avoiding the use of myocutaneous flaps. This is a retrospective and descriptive case report based on data from clinical records, patient observation and analysis of complementary exams. We present the case of a 57-years-old obese woman with prior history of double approach with posterior instrumentation and spine arthrodesis (D3 to L4) due to severe dorsolumbar adolescent idiopathic scoliosis. She presented to our consult 42 years after surgery, complaining of lower back pain. Clinical observation and imaging exams demonstrated degenerative disc disease in L5-S1 and L5 anterolisthesis. There was also distal instrumentation breakage (right L4 pedicular screw and contralateral rod) with pseudarthrosis suspicion. Distal instrumentation was removed and no pseudarthrosis was found. Therefore, posterior instrumentation and arthrodesis was performed, from L4 to S1. Surgery went without complications. One week after surgery, patient developed fever and inflammatory signs at the surgical incision, with purulent oozing. Escherichia coli and Proteus mirabilis were identified as the causative agents. Decision was made to remove both lumbar and distal dorsal instrumentation and perform aggressive debridement and lavage, with debridement surgery being repeated twice. Finally, a full thickness defect with approximately 20cm long and 6cm wide resulted from the debridement. A vacuum dressing was then applied, for 5 weeks, with progressive decrease in clinical and analytical inflammatory parameters and wound closure. Four months after the initial surgery, patient was discharged with complete defect closure and reepithelialization. This dressing technique provided a sound solution for defect resolution, as well as an important aid for infection control. It proved to be a viable option in an extensive defect, when surgical flap techniques and traditional dressing techniques could not provide a complete solution

In recent years internal fixation of the spine by using posterior approach with minimally invasive and percutaneous technique were increasingly used in trauma. The percutaneous surgery lose information and navigation is supposed to provide better data because the lost information is found again. We hypothesise that a percutaneous minimal invasive dorsal procedure by using 3D intra-operative imaging for vertebral fractures allows short operating times with correct screw positioning and does not increase radiation exposure.

59 patients were included in this prospective, monocentric and randomised study. 29 patients (108 implants) were operated on by using conventional surgical procedure (CP) and 30 patients (72 implants) were operated on by using a 3D fluoroscopy-based navigation system (3D fluo). In the two groups, a percutaneous approach was performed for transpedicular vertebroplasty or percutaneous pedicle screws insertion. In the two groups surgery was done from T4 level to L5 levels. Patients (54 years old on average) suffered trauma fractures, fragility fractures or degenerative instabilities. Evaluation of screw placement was done by using post-operative CT with two independent radiologists that used Youkilis criteria. Operative and radiation running time were also evaluated.

With percutaneous surgery, the 3D fluo technique was less accurate with 13.88% of misplaced pedicle screws (10/72) compared with 11.11% (12/108) observed with CP. The radiation running time for each vertebra level (two screws) reached on average 0.56 mSv with 3D fluo group compared to 1.57 mSv with the CP group. The time required for instrumentation (one vertebra, two screws) with 3D fluo was 19.75 minutes compared with CP group 9.19 minutes. The results were statistically significant in terms of radiation dose and operative running time (p < 0.05), but not in terms of accuracy (p= 0.24).

With percutaneous procedures, 3D fluoroscopy-based navigation (3D fluo) system has no superiority in terms of operative running time and to a lesser degree in terms of accuracy, as compared to 2D conventional procedure (CP), but the benefit in terms of radiation dose is important. Other advantages of the 3D fluo system are twofold: up-to-date image data of patient anatomy and immediate availability to assess the anatomical position of the implanted screws.

Aims: Aim of this prospective clinical study was to prove whether there are clinical differences between ms VTS with interposition of an autogenic tricortical bone graft alone and a consecutive dorso-ventral procedure for A 1.2 and A 3.1 fractures of the thoracic and lumbar spine. Materials und Methods: From 01/2002 to 12/2003 298 pat. with traumatic fractures of the thoracic and lumbar spine were treated and had a prospective clinical and radiological follow-up according to the mc-study of the DGU. For 29 pat. (14 m, 15 f; mean age 33 y) ms VTS was performed either isolated (10) or consecutive after dorsal instrumentation (19). Over the post-OP course with a follow-up of 18 mo. the pat. underwent a questionnaire concerning the morbidity at the surgical approaches, the subjective back function and the Odom-score. The osseous integration of the graft and the resulting loss of correction were investigated within the follow-ups 3, 6, 12 and 18 mo. post-OP. Results: Concerning the anterior column 83% of the pat. had type A 3.1.1 fractures. All pat. with type B and C injuries underwent consecutive dorso-ventral instrumentation in 2 sessions. In one case revision surgery with bisegmental replacement of the affected vertebral body by a distractible cage was performed due to osteolysis of the bone graft. The other 28 pat. had no intra- or post-OP complications associated with the autogenic bone graft. At the 12 mo. follow-up osseous integration of the bone graft was observed in 28/29 in the CT-scans. The dorsal instrumentation could be removed in 8 of the 19 pat. with a dorso-ventral procedure after a mean of 12,6 mo. The measurements of the CT-scans at 18 mo. showed an average loss of correction (bisegmental) of 1,5° in the isolated ventral group and of 2,7° in the dorso-ventral group (p < 0,05). After 18 mo. Odom-score and subjective back function increased by 49% respectively 57% compared to the post-OP values (p< 0,05). Concerning the morbidity at the surgical approaches the pat. stated a pain relief of up to 73%. Conclusions: Ms VTS with interposition of an autogenic bone graft of the iliac crest is an appropriate and meanwhile standardized minimal-invasive procedure with a low morbidity at the surgical approach. In this study a high potential for graft integration with a low amount of loss of correction could be detected in both groups (p < 0,05). For the mentioned indications the isolated ventral technique can be seen equal to the dorso-ventral procedure in 2 sessions. However the indication for an isolated ventral procedure has to be reconsidered carefully concerning increasing age and level of osteoporosis

Introduction and purpose: The purpose of our study is to make a critical review of our experience and find a method of systematised, objective therapeutic strategy in the treatment of vertebral metastases. Materials and methods: We reviewed 38 cases of vertebral metastasis (1995–2004) from primary tumours: lung 21%, breast 21%, prostate 12%, renal 12%, ovary 8%, tongue 4%, cavum 4%, melanoma 4%, unknown primary tumour 17%. 24 cases were treated surgically in terms of the clinical criterion agreed between oncologist and traumatologist. We reviewed the follow-up of the cases (treatment, complications, mortality) and the subsequent application of the Tokuhashi prognostic index and the Tomita therapy protocol with two objectives: to evaluate our results and assess these two methods as working tools. Results: 74% of the patients had preoperative radiotherapy. The surgical treatment was corporectomy and dorsal decompression (17%), partial corporectomy and dorsal decompression (29%), decompression and dorsal instrumentation (37%) and non-instrumented decompression laminectomy (17%). The mean survival was 17 months. The surgical treatment controlled pain in 87%; there was neurological improvement in 21%, control in 54% and progression in 25%. Conclusions: Our results were not as good as those found in the literature, in which the usefulness of postoperative radiotherapy is emphasised. Preoperative radiotherapy may have made tumour excision more difficult which, together with the delayed decision-making, influenced the loss of efficacy in our cases. We need more prospective studies to validate the Tokuhashi index and the Tomita protocol, which we think are very useful in taking therapy decisions

Background: To assess the accuracy of pedicle instrumentation placement using an image guidance system ( Medi Vision) in a pig cadaveric model. Methods: A 4mm diameter (10cm long) screw was inserted transversely into the spinous process of a pig cadaver percutaneously using fluoroscopic guidance. The dynamic reference base (DRB) of the image guidance system was then attached to the screw. Using the navigation system both pedicles at each level were identified and 3.2mm guide wires inserted percutaneously. This process was performed for each level from D7 to L4. Actual wire placement was recorded using standard anteroposterior and lateral fluoroscopic images. Virtual trajectories generated by the image guidance system were recorded on the guidance system database. Accuracy of wire placement was then evaluated in an automated way by linear correlation between corresponding images. Results: 20 pedicles were instrumented at 10 levels from D7 to L4. Mean estimate of accuracy for dorsal levels AP and lateral (mm). Mean = 1.452mm, standard deviation 1.57mm. Mean for lumber levels= 1.047mm, standard deviation 1.187mm. Conclusion: Lumbar pedicle instrumentation showed more accuracy when compared to dorsal pedicle instrumentation. The error of navigation that was accommodated by the image guidance system was 2mm. There was correlation between fluoroscopic copies and virtual trajectories. This image guidance system may not only aid in the placement of pedicle instrumentation but also assist the senior surgeon in trainee supervision

Aim of Study: (A) To study what causes Anterior Column Deficiency in Burst Fracture of Dorso Lumbar Spine in the acute and later phase. (B) To analyse radiologically, the significance of adjacent disc injuries in burst fracture of dorso lumbar spine. (C) To look into the effectiveness of posterior short segment stabilisation by pedicle screw fixation and fusion in these injuries, in relation to deformity and anterior column deficiency. Methods and Materials: Twenty consecutive cases of Superior Burst-split fracture of Dorsolumbar spine were studied prospectively. All cases underwent reduction, posterior short segment stabilisation by Steffee type pedicle screw fixation and two level posterolateral fusion. The average follow-up duration was 30.2 months. Standardised AP and lateral radiograph were taken pre-operatively and post-operatively at regular intervals (every three months). Radiological assessment using seven parameters (Vertebral body angle, Upper disc angle, Lower disc angle, Kyphotic angle, etc) were done from these radiographs. Result and Significance: The total average correction of kyphosis (in degree) at surgery was 21.5°, and the proportion of correction during surgery was – Upper disc 29% (6.3°), Vertebral body 68% (14.6°) and Lower disc 3% (0.6°). So 68% of the correction was at the vertebral body level and 32% at the adjacent discs levels. At follow-up, the total average loss of correction was 16.5°, and the proportion of loss at follow-up was – Upper disc 44% (7.2°), Vertebral body 14% (2.3°) and Lower disc 42% (7.0°). There was loss of 14.2° at the disc levels compared to 2.3° only at the vertebral body level. So 86% of the loss was at the adjacent disc levels. Conclusion: Distraction at the adjacent disc levels occurred at surgery while contouring the vertebral body using dorsal instrumentation. The distraction at the upper disc level was significant. Distraction at adjacent disc levels resulted in more anterior column deficiency. At follow-up, the loss in the vertebral body was minimal and most of the loss occurred at the adjacent disc levels. The anterior column deficiency caused by the injury to the adjacent disc is very major cause for failure of dorsal instrumentation than the deficiency caused by the vertebral body. The upper disc is more severely injured than the lower disc in the superior burst split fracture and so the degeneration is rapid in the upper disc and gradual in the lower disc. The CT cuts at the end plate levels of the vertebral body can help to judge roughly the extent of injury to the adjacent disc. Posterolateral fusion and late disc degeneration after consolidation of fusion result in collapse of the disc in kyphotic angulation, as it prevents collapse of posterior disc height

Introduction: The role of transpedicular bone graft for the stability after dorsal instrumentation of fractures of the thoracolumbar spine is still not clear whereas the morbidity of harvesting the bone from the iliac crest is evident. In a clinical study we examined the clinical outcome, radiological signs of instability and the vitality of the bone by MRI. Methods: We examined 45 patients who underwent posterior instrumention for fractures of the thoracolumbar spine between 1988 and 1997 and had removal of the implants more than 3 months ago. All patients had received a interspinal and interlaminar bone graft, 23 patients had received an additional transpedicular bone graft. We measured the clinical outcome by a standardized questionnaire and the stability of the spondylodesis by native and functional Xrays. The vitality of the transpedicular bone graft was examined by MRI. Results: There were not significant differences in both study-groups concerning the clinical outcome. In both groups we saw one case with radiological signs of instability. In the MRI-examination 18 of the 23 patients with a transpedicular bone graft showed a vital graft. In 5 cases the transpedicular bone graft showed no increase of the signal intensity after contrast media which was interpreted as a avital graft. Discussion: Although the support of the anterior column in the posterior instrumentation by a transpedicular bone graft is theoretically meaningful we saw no correlation to the clinical outcome. Considering our results and the donor site morbidity, the use of transpedicular bone graft must be discussed critically

The goal of the present study is to investigate if one of the two dorsal operative procedures (rod-rotation versus translation technique) leads to a better radiographic correction of idiopathic adolescent thoracic scoliosis after operative treatment. The operative technique in scoliosis surgery introduced by Cotrel and Dubousset attempts to achieve an improvement of the sagittal profile and a derotation of the vertebrae, in addition to a correction of the main curvature of the scoliotic spine by rotation of the convex-side rod (rod-rotation). The technique of segmental correction was described by Luque. Correction of the scoliosis is performed after fixation of each vertebral body with wire cerclages, followed by segmental correction of the deformed spine. The Universal Spinal System was introduced and an operating technique was developed to take advantage of the principle of segmental correction of scoliosis (translation technique). The radiographic outcomes in two groups comprising a total of 69 adolescent patients treated for idiopathic thoracic scoliosis with dorsal instrumentation by the use of a unified implantation system (Universal Spinal System) were compared retrospectively by an independent observer. In 30 patients an intraoperative correction of the scoliosis was performed by translation technique (translation group) and in 39 patients the correction was achieved by Cotrel-Dubousset instrumentation (rod-rotation group). The mean follow-up interval was 40 months with a minimum of 12 months. The preoperative radiographic measurements of the scoliotic spines showed no significant differences between the two groups. In both patient groups, the thoracic primary curve, lumbar secondary curve, and apical rotation of the thoracic curve were improved by the operation. The thoracic primary curve was corrected from 50 6° to 24 7° (p< 0.01) in the translation group and from 54 11° to 22 11° (p< 0.01) in the rod-rotation group. The extent of the correction of the thoracic curve was significantly greater in the rod-rotation group than in the translation group (59% versus 52% correction; p< 0.01). Thoracic apical rotation was corrected from 21 ± 9° to 16 ± 10° (p< 0.01) in the rod-rotation group and from 19 ± 9° to 17 ± 7° (p< 0.05) in the translation group. Lumbar apical rotation and the sagittal profile were unchanged in both groups. Based on the results of this study with a small number of patients, the ability of the translation technique to correct the thoracic major curvature seems to be less than that of the rod-rotation technique. No differences are to be expected in the correction of the lumbar minor curvature or of the rotation of the thoracic apex. Neither procedure is expected to influence the sagittal profile or lumbar rotation