Expedium Verse System
Philip Horsting, Jean Ouellet
The Expedium Verse pedicle screw system (Fig 1 below) combines the attributes of multiple screw types (side-loading, monoaxial, polyaxial, uniplanar, and reduction screws) while offering intraoperative flexibility allowing surgical staff to address unplanned circumstances with one versatile implant. This ultimately results in the delivery of a more predictable intraoperative experience for the treatment of both adult and paediatric spine deformity.
The Expedium Verse implant incorporates technology that allows for converting the polyaxial screw into a monoaxial screw while allowing for translation along the rod. The correction key is used as a locking mechanism that provides independent locking of polyaxial head and rod.
Easier rod capture with powerful and controlled correction
The "hypermobility" or increased angulation (Table 1) of the polyaxial head in combination with the reduction tabs simplify rod capture while providing a powerful threaded reduction mechanism that accommodates controlled approximation of the spine to the rod. The pedicle screws serve as a powerful instrument in the facilitation of correction maneuvers.
The result is a great reduction in the number of instruments required for fusion procedures, potentially simplifying the surgical instrument table and reducing the costs associated with the sterilization process. The Expedium Verse pedicle screw can be converted into a monoaxial implant while allowing the screw to articulate around the rod. Tighten the poly lock of the correction key with the torque limiting handle while applying counter torque to lock the polyaxial head (Fig 2).
Instrument design and set configuration
Through the redesign and feature enhancement on both the instruments and implants, it was possible to significantly reduce the number of instruments when compared to a traditional system such as the Expedium 5.5, enabling a shift away from instrument based correction methods to a more implant based procedure.
The polyaxial screwdriver modular design also allows for intraoperative assembly and includes tissue protection sleeves (Fig 3).
The Expedium Verse system provides a flex clip reducer (Fig 4) known from the Expedium 5.5 system for surgeons in case a reduction tab is accidentally or intentionally removed prior to reducing the rod into the screw head.
A tab remover has been provided for removal of the Expedium Verse screw reduction tabs at the completion of the procedure (Fig 5).
Please refer to Expedium Verse IFU for complete listing of warnings, contraindications and precautions.
Cases provided by Philip Horsting, Nijmegen, Netherlands
Case 1: Teenage boy with intellectual disability
Twelve months prior to his first visit to our clinic, the father of this 17-year-old intellectually disabled boy found a scoliosis, later confirmed by his therapist.
The patient was physically grown comparable to his age but mentally functioned at a 2-year-old level. No syndromic diagnosis was made after visits to a pediatrician. He had been diagnosed with severe autism. Behavioural changes might be suggestive of pain. The patient was unable to specifically indicate pain or (progressive) limitations.
On physical examination a cooperative boy was seen, normal build and height, normal to high paraspinal muscle tone. Standing upright he was off balance to the right. Neurological examination showed absent abdominal skin reflexes bilaterally. The curve was classified as neuromuscular type scoliosis (Fig 6). Due to the curve magnitude, being off balance, and with (severely) limited nonoperative options (Fig 7), surgical treatment was discussed with the family.
He was scheduled for a posterior deformity correction from T4L3. Under general anesthesia, with IONM (TC-MEP) the deformity was corrected. Intraoperatively, an epidural catheter was placed with the tip at T7 for postoperative analgesia.
Mobilisation started the day after surgery. He was discharged the fourth day after surgery. He returned for scheduled follow-up after 7 weeks (Fig 8). He seemed less agitated compared to the period before surgery. He did not seem to have specific limitations.
Case 2: 17-year-old female patient
The patient was known and under orthopedic control for a Lenke 5C-type AIS since 2009. Initial treatment with a Boston Brace failed to halt progressive growth, and curve progression became apparent beyond surgical treatment threshold (Fig 9). Bending FS showed TL correction 58 -> 30 (plm 50%). MT correction 43 -> 16 (plm 35%) (Fig 10). The patient was referred to our hospitalfor logistics regarding surgical planning.
After her visit to our clinic, she was planned for surgical correction of the deformity from T5L4 (Fig 11). Surgical procedure with IONM (TC-MEP) postoperative epidural analgesia with the catheter tip at T8. She was mobilised the first postoperative day (Fig 12) and discharged the fourth day after surgery. The patient returned for her 6-month follow-up without any complaints. Limitations are in line with our advice (no sports for 6 months postoperatively). She has no pain and uses no medication.
A novel implant-based solution to spinal deformity correction
Hazards and labeling
Due to varying countries’ legal and regulatory approval requirements, consult the appropriate local product labeling for approved intended use of the products described on this website. All devices on this website are approved by the AO Technical Commission. For logistical reasons, these devices may not be available in all countries worldwide at the date of publication.
This work was produced by AO Foundation, Switzerland. All rights reserved by AO Foundation. This publication, including all parts thereof, is legally protected by copyright.
Any use, exploitation or commercialization outside the narrow limits set forth by copyright legislation and the restrictions on use laid out below, without the publisher‘s consent, is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, scanning or duplication of any kind, translation, preparation of microfilms, electronic data processing, and storage such as making this publication available on Intranet or Internet.
Some of the products, names, instruments, treatments, logos, designs, etc referred to in this publication are also protected by patents, trademarks or by other intellectual property protection laws (eg, “AO” and the AO logo are subject to trademark applications/registrations) even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name, instrument, etc without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.
Restrictions on use: The rightful owner of an authorized copy of this work may use it for educational and research purposes only. Single images or illustrations may be copied for research or educational purposes only. The images or illustrations may not be altered in any way and need to carry the following statement of origin “Copyright by AO Foundation, Switzerland”.
Check www.aofoundation.org/disclaimer for more information.
If you have any comments or questions on the articles or the new devices, please do not hesitate to contact us.
"approved by AO Technical Commission" and "approved by AO Foundation"
The brands and labels "approved by AO Technical Commission" and "approved by AO Foundation", particularly "AO" and the AO logo, are AO Foundation's intellectual property and subject to trademark applications and registrations, respectively. The use of these brands and labels is regulated by licensing agreements between AO Foundation and the producers of innovation products obliged to use such labels to declare the products as AO Technical Commission or AO Foundation approved solutions. Any unauthorized or inadequate use of these trademarks may be subject to legal action.