Asymmetric pedicle subtractionosteotomy (aPSO) guided by a 3D-printed model to correct a combined fixed sagittal and coronal imbalance.

Surgical correction of fixed thoracolumbar deformity is usually achieved by estimating the preoperatively planned correction angles during surgery and is therefore prone to inaccuracy. This is particularly problematic in biplanar deformities. To overcome these difficulties, 3D model for planning, preparation, and simulation of an asymmetric pedicle subtraction osteotomy (aPSO) was printed and used to realign coronal and sagittal balance in case of rigid degenerative kyphoscoliosis. A 59-year-old woman presented with severe back pain and spinal claudication and was diagnosed with a rigid kyphoscoliosis with multilevel spinal stenosis. Spino-pelvic parameters were measured preoperatively (pelvic incidence 47° [PI], lumbar lordosis 18° [LL]; pelvic tilt 42° [PT], T1 pelvic angle 40° [TPA], Cobb angle 33°, sagittal vertical axis 10.5 cm [SVA]). To aid the complex deformity in the sagittal and coronal plane, a 1:1 3D model of the spine was printed according to the preoperative computed tomography (CT). With the use of a rebalancing software, the spine was prepared in vitro as a model for intraoperative realignment and the correction was preoperatively simulated. Surgery was accomplished according to the preoperative software-guided plan. Asymmetric pedicle subtraction osteotomy (aPSO) of L3 identical to the 3D model was performed. Additionally, a Smith-Peterson osteotomy of L4/5 with transforaminal lumbar interbody fusion (TLIF) and laminectomy of L2-S1 with pedicle screw instrumentation TH12-S1 was accomplished. Postoperative radiological parameters revealed good success (LL 40°, SVA 6 cm, PT 19°, TPA 22°, and a Cobb angle of 8°). Improvement of the Oswestry disability index (ODI) of 42 to 18, the visual analog scale (VAS) of 8 to 1, and walking distance 100 to 8000 m compared to preoperatively resulted at 24 months follow-up. The precise coronal and sagittal correction of a rigid degenerative kyphoscoliosis presents a major challenge. Asymmetric PSO is able to realign the thoracolumbar spine in both the coronal and sagittal planes. The creation of an in vitro 3D-printed model of a patient's spinal deformity in combination with a software to calculate the correction angles facilitates preoperative planning and implementation of aPSO.

Cervical arthroplasty with ROTAIO® cervical disc prosthesis: first clinical and radiographic outcome analysis in a multicenter prospective trial.

BACKGROUND: Cervical Disc Arthroplasty (CDA) seems to be an alternative to Anterior Cervical Decompression and Fusion (ACDF) and was developed to minimize the risk of Adjacent Segment Disease (ASD). The ROTAIO Cervical Disc Prosthesis represents a new unconstrained implant with a variable centre of rotation which should enable physiological facet-guided movement. The aim of this current study was to evaluate the clinical outcomes after arthroplasty using ROTAIO Cervical Disc Prosthesis. METHOD: Twenty-seven female and 18 male patients (n = 45) with a mean age of 43.7 ± 7.8 years were prospectively followed up for a maximum of 24 month. Clinical outcomes were assessed by Neck Disability Index (NDI), visual analogue scale (VAS) scores for neck and arm pain, patients´ overall satisfaction and the usage of analgesics. Additionally, radiographic information including ROM of the functional spinal unit (FSU) and signs of adjacent segment disease were recorded. RESULTS: NDI and VAS scores showed significant improvement 6 months after surgery and at last follow-up (p < 0.001). Concerning overall satisfaction 95.7% of the patients showed good to excellent results at the last visit and a significant reduction of analgesic usage was observed (p < 0.001). Radiographic measurements showed a mean increase of ROM up to 8.40° in the treated FSU at last follow-up (p < 0.001). No signs of anterior migration or dislocation of the prosthesis and no subsidence was recorded radiographically. There were no major complications and a low rate of secondary procedures (2.2%). CONCLUSION: In the 24-months follow-up the ROTAIO Cervical Disc Prosthesis provided excellent clinical and radiographical results and seems to be safe and effective for the treatment of symptomatic single-level degenerative disc disease.

Ultrasound guided versus CT-controlled pararadicular injections in the lumbar spine: a prospective randomized clinical trial.

BACKGROUND AND PURPOSE: Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT- or fluoroscopic guidance. We conducted this study to evaluate the accuracy, time savings, radiation doses, and pain relief of US-guided pararadicular injections versus CT-controlled interventions in the lumbar spine in a prospective randomized clinical trial. MATERIALS AND METHODS: Forty adult patients were consecutively enrolled and assigned to a US or CT group. US-guided pararadicular injections were performed on a standard US device by using a broadband curved-array transducer (9-4 or 5-1 MHz). In the in-plane technique, the needle was advanced through the respective segmental intertransverse ligament. The needle tip position was verified by CT. The CT-guided approaches were performed under standardized procedures by using the CT-positioning laser function. RESULTS: The accuracy of US-guided interventions was 90%. The mean time to final needle placement in the US group was 4.0 ± 1.8 minutes, and in the CT group, 7.6 ± 2.1 minutes. The mean radiation doses, including CT confirmation for study purposes only, were 20.3 ± 9.0 mGy cm for the US group and 42.6 ± 36.1 mGy cm for the CT group. Both groups showed the same significant pain relief (P < .05) without relevant "intermethodic" differences of pain relief (P > .05). CONCLUSIONS: US-guided pararadicular injections show a therapeutic effect similar to that in the time-consuming, expensive, ionizing CT or fluoroscopically guided pararadicular injections and result in a significant reduction of procedure time expenditure and avoidance of radiation.

A new simplified sonographic approach for pararadicular injections in the lumbar spine: a CT-controlled cadaver study.

BACKGROUND AND PURPOSE: Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT or fluoroscopic guidance. The benefits of US-guided instillation procedures have been shown in many studies. We conducted this study to simplify an US-guided approach to the lumbar spinal nerves and to assess the feasibility and preliminary accuracy by means of CT and anatomic dissection. MATERIALS AND METHODS: Ten US-guided injections at 5 different levels (L1-L5) were performed on 1 embalmed cadaver. Images in 3 sagittal/parasagittal scanning planes were obtained at each lumbar level: 1) the plane of the spinous processes, 2) the plane of the lumbar arches/zygapophyseal-joints, and 3) the plane of the transverse processes. The PAP was then defined by positioning the transducer perpendicularly over the medial part of the respective transverse processes, depicting the hyperechoic intertransverse ligament. In the "in-plane technique," spinal needles were advanced through the respective segmental intertransverse ligament. A solution consisting of a contrast agent and a pigmented dispersion was subsequently injected into the pararadicular compartment. An anatomic dissection of the specimen and CT scans were performed to verify the exact placement of the needle tips and to evaluate fluid dispersion in the punctured compartment. RESULTS: CT examination confirmed that each needle tip was correctly placed within the intended compartment with sufficient contrast accumulation around the respective proximal segment of the spinal nerve. On each anatomic section, dye was identified in the correct compartment and directly around each targeted spinal nerve with needles shown in the correct position. CONCLUSIONS: This modified US approach for therapeutic root injections in the lumbar spine by using the intertransverse ligament as a new anatomic landmark allows an easy and correct needle placement within the pararadicular compartment.