Adult Scoliosis with a Broken Rod and Progressive Kyphosis
SpineAssist® Robotic Guidance System Precisely Solves Surgical Challenge
The patient is a 59-year-old female who presents with mechanical back pain, radiating buttock and leg pain, and progressive spinal deformity. She has trouble lifting and carrying things, and during recreational activities. Her symptoms have persisted since a slip injury a few months ago.
Three years ago she underwent anterior lumbar spine reconstruction for scoliosis. Her outcome was excellent. Past non-spine procedures include rotator cuff repair, sinus and foot surgeries. She takes supplements to treat osteopenia and medications to manage blood pressure, asthma, depression, restless leg syndrome, and rheumatoid arthritis.
She does not smoke and rarely drinks alcoholic beverages. The patient is married and works full-time as a product manager.
Review of systems is normal.
- Stance is slightly stooped forward, pelvis slightly retroverted, knees flexed
- Walks with a free unrestricted gait
- Free and active range of motion (ROM): shoulders, elbows, hips, knees
- Very restricted ROM: lumbar flexion and extension
- Lumbar extension exacerbates back and leg pain
- Some discomfort over the mid thoracic kyphotic segment
- Sacralized L5 segment
Neurological and Vascular Examination
- Upper and lower extremities: no motor, sensory or reflex abnormalities
- No evidence of myelopathy or radiculopathy
- Peripheral pulses normal
Standing anteroposterior (AP) and lateral x-rays (Figs. 1A, 1B).
Figure 1A. AP x-ray
Figure 1B. Lateral x-ray
- Broken rod (L1-L2) with pseudoarthrosis
- Progressive kyphotic deformity
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- Posterior T6 to L3 segmental instrumentation, correction and fusion
- Placement of pedicle screws using computer-assisted robotic guidance (SpineAssist® Surgical Guidance System, Mazor Robotics Ltd.)
- T12-L1 and L1-L2 Smith-Petersen osteotomies
Video 1. Dr. Lieberman uses SpineAssist to explain the challenges this case presents
Through a midline incision, exposed levels T6 to L3. Next, dissection was extended to the tips of the transverse processes. Fluoroscopic imaging verified the levels. Resection of the facet joint capsules exposed the facet joints from L2-L3 up to T6-T7. Levels T12-L1 and L1-L2 are mobile. L2-L3 clearly is fused.
Bone marrow aspirate (BMA) was taken from the right posterior superior iliac spine. BMA will augment the cancellous allograft chips for the bone graft slurry.
Two temporary pins were placed into the posterior superior iliac spines, and a small spinous process clamp through a separate skin incision proximally at T2-T3, to mount the Hover-T frame to facilitate computer-guided placement of the robotic screws. The Hover-T and Registration Device (Fig. 2A) were attached (Fig. 2B).
Figure 2A. Hover-T frame
Figure 2B. Hover-T and Registration Device
Video 2. Summary of the functional aspects of SpineAssist include surgical pre-planning, Hover-T mounting options, 3D synchronization, and its use in the operating room.
Oblique and AP fluoroscopic images (Figs. 3A, 3B) provided excellent images for registration. Pleased with the registration, the Registration Device is removed and pedicle screw placement began.
Figure 3A. Oblique x-ray, T4-L5
Figure 3B. AP x-ray, T4-L5
The robot was mounted along the Hover-T stations. It was sequentially dispatched to each level to bilaterally implant pedicle screws at L3, L2, L1, T12, T11, T10, and T9 (Figs. 4A-4C). One screw was implanted on the right at T8 and another on the left at T7. Bilateral screws were implanted at T6. All screws achieved excellent purchase. Intra-operative x-rays confirmed each screw was in good position.
Two rods were contoured in preparation for the instrumentation. The Hover-T frame and robot were removed. Smith-Petersen osteotomies were performed at L1-L2 and T12-L1 to tilt the spine back into lordosis hinging on the posterior vertebral bodies. Pleased with the osteotomies and mobility of the spine, the contoured rods were fastened proximally on the right-hand side followed by segmental reduction from T6 through L3. Next, rod insertion was repeated on the left-hand side. All collars and nuts were appropriately placed and tightened. Fluoroscopy verified all aspects of the construct.
The laminae, facet joints, and pars interarticulari were decorticated from T6 to L3. The spinous processes were resected from T7 to L3, morselized and mixed with local bone, allograft cancellous bone, and BMA. The bone graft slurry was packed into the posterolateral gutters across the laminae, facet joints, and pars interarticulari. The incision was closed in layers.
Intra-operative fluoroscopy; pedicle screw placement, Figures 4A through 4C.
Figure 4A. PA, T6-T12
Figure 4B. Lateral, T6-T12
Figure 4C. PA, T12-L3 (with Hover-T frame)
There were no surgical complications. Waveform amplitudes with somatosensory-evoked potentials (SSEPs) were normal throughout the procedure. Although, there was some difficulty with the motor-evoked potentials (MEPs), the technician obtained good MEPs from all four extremities at the end of the case.
The patient was discharged to a rehab center on post-operative day four. She was progressing well with physical therapy, ambulation, and functional activities.
Surgeon's Treatment Rationale
Recently, image-guided surgery has evolved even further with the introduction of robotic guidance. Robotic-guided spine surgery uses the same pre-operative CT scans to create a pre-operative plan of the surgical procedure in a 3D virtual environment. It couples the pre-operative plan with sophisticated software and an advanced robotic arm to facilitate the plan with ultimate precision. Extremely accurate placement of spinal implants can be achieved even under the most challenging conditions as demonstrated in this case.
At two-weeks: The patient is doing exceptionally well and has minimal complaints. The incision is well-healed. Neutral alignment is restored and the instrumentation is in good position. Squat exercises are added to allowed daily activities.
Figure 5A. Two-weeks post-op AP
Figure 5B. Two-weeks post-op lateral
At six-weeks: She continues to improve, has no neurologic deficits, and is compliant with daily activities that are allowed. An active exercise program is started.
At two-months: Her posture is normal, although she has a slight antalgic gait. There is some evidence of nerve root tension with straight leg raising at approximately 75-degrees, but no other substantial neurologic deficits. It is suspected that physical therapy has aggravated a radiculopathy. Exercises that exacerbate symptoms are eliminated at this time. An MRI will be obtained if symptoms persist.
At six-months: AP and lateral x-rays (Figs. 6A, 6B).
Disclaimer: Dr. Isador H. Lieberman’s financial disclosures include his role as one of the developers of Mazor Robotics’ technology.
Information for Professionals: The descriptions of the use of SpineAssist® Surgical Guidance System (Mazor Robotics Ltd.) in this sponsored case presentation are based on the physician's actual experience. The results achieved in any particular case using SpineAssist can vary and the results achieved in the case may not be typical. SpineAssist should be used for only those indications described in the FDA-cleared indications for use and User Manual; copies of which may be obtained by contacting Mazor Robotics Ltd. Refer to the FDA-cleared indications for use and User Manual for a more complete description of indications, contraindications, warnings and other information about the product.
Information for Patients: Spine surgery is not for all patients. Please consult your doctor for information about treatment indications, warnings, precautions, and other important medical information.
Additionally, Mazor Robotics introduces RENAISSANCE™, its new Surgical Guidance System.
Visit www.MazorRobotics.com for more information on Renaissance.
This is an interesting and innovative approach to a classic case—that of pseudoarthrosis, broken instrumentation and increasing loss of sagittal balance. I like the idea of turning a revision operation into a primary. By that (in this case), I mean going posteriorly when the index procedure was done anteriorly. The challenge in this case remaining is that of the previously implanted vertebral body screws. The image guidance system was nicely deployed to avoid the existing screws. There are many systems now available that could have accomplished this and the surgeon should use that with which he or she is comfortable.
When correcting kyphotic problems in any patient with pre-existent kyphosis, we worry about proximal junctional kyphosis. Suggestions to help avoid this include insuring ongoing maximized bone density, an extensor strengthening program for the thoracic spine, and consideration of a proximal junctional vertebroplasty one or two levels above the proximal construct.
I congratulate Dr. Lieberman on a unique and excellent treatment of this problem.