Spine Surgeon Case Studies

C5–T5 posterior cervical fusion with partial corpectomy

T12-L3 fixation across L2 burst fracture 

Percutaneous Stabilization of L1-L2 Using Minimal Access Spine Technologies

Pedicle Screw Placement Utilizing Multiple Navigation Modalities

C5–T5 posterior cervical fusion with partial corpectomy

Patient Profile

55 year old female, weighing about 325 lbs, with a T1-T2 tumor.

Operation

Dr. Jonathan Sherman, Mission Memorial Hospital, February 2007

The patient was transferred to a Jackson surgical table and the O-ARM® System positioned for AP and lateral fluoro projections. The O-ARM® System was articulated toward the head end of the table, draped, and parked allowing maximum space of the surgical field.

All O‑ARM® System positional data was saved and later recalled for precise, robotically controlled positioning during the case. A reference frame was attached to the spinous process of the cervical spine and an intraoperative 3D scan acquired with the patient in the final surgical position. The images and patient reference data were automatically transferred to the StealthStation® Treon® System through a network connection. Fully registered images were available at the StealthStation® Treon® System allowing immediate navigation in the axial, coronal, and sagittal planes. In addition, precise AP and lateral projection are transferred for display on the StealthStation® Treon® System.

The Navigation display provides full feedback so that the surgeon can map and follow the path of the pedicle probe and screw placement from the multiplanar images. Pedicle screws were advanced from C5 through T5 before a partial corpectomy at T1-T2. Additional AP and lateral imaging was quickly obtained with the O-ARM® System with minimal intrusion. An additional post completion 3D scan can be performed to confirm accuracy and may also obviate the need for post-op CT.

Comments

“The O-ARM® System takes a complex surgery like this and makes it seem routine.”
Dr. Jonathan Sherman

[1] Snapshot of O-ARM® System 3D spin images using the XL chest technique setting after insertion of pedicle screws in the thoracic and cervical regions.

T12-L3 fixation across L2 burst fracture

Patient Profile

27-year-old male with L2 burst fracture from ski-jumping accident.

Operation

Dr. Don Corenman, Vail Valley Medical Center, Colorado, February 2007

The patient’s anatomy is somewhat mobile and misaligned with this type of vertebral fracture and reduces the natural lordosis of the spine. As a result, preoperative imaging (CT) is of limited use for navigation, and 2D imaging is limiting in that it does not provide valuable axial views. The O-ARM® System with StealthStation® System navigation allowed the surgeon to visualize his pedicle preparation and screw placement at all affected levels while utilizing Medtronic Spinal and Biologics instrumentation. Additionally, the O‑ARM® System in combination with the StealthStation® System may reduce surgeon and staff radiation exposure.

After the pedicle screws and rods were placed, the surgeon was able to employ the O‑ARM® System to determine the amount of correction made to the fragmented vertebral body and resultant lordotic alignment. In this instance, the surgeon discovered that bone fragments did not reduce back to normal position and subsequently decided to perform a more aggressive correction. Utilizing the O-ARM® System in this way avoided a second surgery and additional hospital and patient costs, while improving patient outcome. Additionally, it allowed the surgeon to provide a superior level of care to this patient, by assessing his fracture reduction and determining whether or not fragments remained in the canal.

Comments

“This technology is amazing. It is the standard of care on difficult cases like this one.”
Dr. Don Corenman

[1] Snapshot from StealthStation® System display showing navigation of a TSRH‑3D® Spinal System screw with our Awl/Probe/Tap instrument.

[2] Snapshot image of the O-ARM® System display showing the axial, coronal and sagittal views of the burst fracture.

Percutaneous Stabilization of L1-L2 Using Minimal Access Spine Technologies

Patient Profile

Forty-year-old male with instability of spine levels L1-L2. The instability was due to a fracture of L2 healing in a kyphotic position. The patient presented with low back pain and visible deformity. Pre-operative X-ray films showed lordosis causing disc compression at L1-L2 and segmental scoliosis. This is the patient’s first spinal surgery.

Operation

Priv. Doz. Dr. med. Ekkehard Fritsch placed a cage, using an anterior approach, to reestablish disc space, then created a posterior tension band utilizing the StealthStation^® SIREMOBIL^® ISO-C^® 3D interface software to image guide the Medtronic Spinal & Biologics CD HORIZON^® Sextant™ Percutaneous Rod Insertion System. A small incision was made to attach the reference frame, and all anatomical data necessary to perform this procedure was obtained from the Siemens SIREMOBIL ISO-C^® 3D C-arm. Neither surgeon nor operating room staff involvement was required to track the C-arm or register the patient data set. After image acquisition, the C-arm was moved out of the operative field to allow Dr. Fritsch maximum ergonomic access to the patient. An anterior approach was used to obtain a ventral release of L1-L2 segment. The patient was then turned, and the Sextant Percutaneous Rod Insertion System was used to place pedicle screws and rods at L1-L2. The StealthStation^® SIREMOBIL ISO-C^® 3D interface software was used to confirm instrument trajectory and navigate percutaneous screw placement on each side of L1-L2. Dr. Fritsch performed segmental distraction on the right side and segmental compression on the left side to correct segmental scoliosis.

Conclusions

A post-operative scan from the Siemens SIREMOBIL ISO-C^® 3D C-arm was taken after the wound was closed but before the patient left the operating suite. The scans confirmed accurate placement of all four pedicle screws. A complete correction of segmental scoliosis was also achieved. The patient returned from surgery with no neurological deficiencies and was released from the hospital three days later.

Comments

Percutaneous screw placement is typically a very difficult procedure, but with the added benefit of being able to intra-operatively take images and immediately navigate on them, all four were placed correctly in less than one hour.

“In the best of surgical cases, percutaneous screw placement is an extremely difficult and delicate procedure. When you add the considerable benefit of intra-operative image verification and the ability to navigate from those images, the degree of accuracy or correct placement can be improved dramatically. This technology can also decrease surgical times - in this case all four screws were placed in less than an hour.” - Priv. Doz. Dr. med. Ekkehard Fritsch Neurosurgeon Universitätsklinik Homburg/Saar, Germany

Pedicle Screw Placement Utilizing Multiple Navigation Modalities

Patient Profile

A 41-year-old ex-Navy Seal presented with a 10-year history of low back pain. The pain was incapacitating and had kept him out of work for six months. He had failed conservative management including medication, physical therapy, epidural steroid injection and bracing. Physical examination revealed pain localized to a palpable step-off at L5-S1. Numbness and weakness were present in the L5 and S1 distributions bilaterally. Plain spine X-rays detected a mild retrolisthesis of L4 on L5. There were 12 mm of subluxation of L5 on S1 baseline, with 3 mm of motion in flexion and extension. An MRI scan was positive for degenerative disc disease at L4-5 and L5-S1, there was a central disc bulge with lateral recess stenosis at L5-S1. A discogram was strikingly positive for reproduction of the patient’s pain upon injection of L4-5 and L5-S1. The discogram highlighted an annular tear and central disc herniation at L4-5.

Operation

A surgery was planned to restore disc space, height, alignment, and stability at L4-5 and L5-S1. This would be accomplished using posterior lumbar interbody fusions (PLIFs), the TANGENT™ instrument set and the TSRH-3D™ spinal instrumentation, all from Medtronic Spinal & Biologics business. A three-dimensional spine model was reconstructed from a high-resolution lumbar CT scan using the StealthStation^® protocol. Ideal pedicle screw trajectories were planned for L4, L5, and S1 bilaterally. At surgery, the L4, L5, and S1 levels were exposed through a single, midline incision. A reference arc was attached to the L4 spinous process. The L4 level was registered, and the L4 pedicle screws were placed using the StealthStation^® Mach 4.1™ spine software. The StealthStation^® images were then used to mark and score the ideal entry points into the L5 and S1 pedicles. The decompression was then performed at L5-S1. The L5-S1 PLIF was accomplished using two 10 x 20 mm TANGENT grafts plus additional locally harvested patient bone. Using the same reference arc attached to L4, anterior-posterior and lateral fluoroscopy was taken of the L5 and S1 levels. The images were automatically transferred to the StealthStation^® system via the FluoroNav^® virtual fluoroscopy software and immediately available for navigation.

Pedicle screws were placed at L5 and S1 using the FluoroNav^® software. There was excellent correlation between the entry points selected using the StealthStation^® Mach 4.1 software and those seen when utilizing the FluoroNav^® software. Also, there was excellent correlation between the angles of screw placement determined by the FluoroNav^® software, those determined with the pre-planning feature of the Mach 4.1 spine software, and the preoperative radiologic studies. All pedicle screws (L4, L5, and S1) were placed at their optimal trajectory through the single midline incision, lumbo-dorsal facia, and muscle using 16 mm METRx™ guide tubes attached to a Leyla arm. The screws could be seen to engage the pedicles under directed vision, yet minimal muscle retraction was necessary throughout the entire case. The reference arc was removed from L4. A standard decompression, discectomy, and bilateral PLIF procedure was then performed at L4-5. Two 10 x 26 mm Tangent grafts were used. The rods were shaped and placed. The lordotic curve and the proximity of the screw heads prevented placement of cross-links.

Conclusion

The patient experienced immediate relief of his chronic low back pain. The motor strength and sensation were restored in the lower extremities. The patient felt that his incisional pain was minimal compared to his pre-operative pain, and he requested to be discharged home on the first post-operative day. Post-operative X-rays demonstrated excellent screw and graft placement, restoration of the disc space heights, adequate lordosis, and reduction of the L5-S1 spondylolisthesis.

Comments

“This case demonstrates the ability to use the StealthStation^® Mach 4.1 spine software and the FluoroNav^® virtual fluoroscopy software together during a single case. The rigid reference arc fixation at L4 enabled accurate pedicle screw placement within these smaller pedicles using the StealthStation^® Mach 4.1 spine software. The anatomic relationships between L5-S1 changed as the decompression and PLIF were performed. FluoroNav^® virtual fluoroscopy software utilized updated intra-operative fluoroscopic imaging to place screws into the new anatomy. Information learned within one system could be applied when using the other system.” - Charles Haworth, MD Neurosurgeon Duke University School of Medicine Lumberton, North Carolina

NOTE: Each experience described here is specific to a particular patient. Results vary and every response is not the same. Patients should always talk with their doctors to see if they may benefit from this therapy and for a full review of indications and side effects.