Congenital Kyphosis and Difficulty Walking
A 17-year-old male with mild developmental delay has increasing back pain over the last year. He has a long standing deformity, and he and his parents think it has worsened. In the past few months he has begun to have some difficulty with walking quickly, but no trouble with bowel or bladder function. He denies recent illness, weight loss, or fevers. He has undergone multiple prior operations, but none on his spine.
No motor or sensory loss in his upper or lower extremities. His only objective finding is 2 beats of clonus in the left lower extremity. He stumbles with walking quickly in the clinic. He has some moderate pain at the gibbus, and obvious cosmetic deformity.
The patient has had no prior treatment for his spine condition.
Figure 1: Pre-operative sagittal profile
Figure 2: Pre-op AP long cassette. Note the mild degree of scoliosis.
Figure 3: Lateral long cassette film showing persevered spinal balance despite
Figure 4: Lumbar spine close of thoracolumbar deformity, indication of 78° of kyphosis from T9 to L1. Close inspection shows 3 pairs of pedicles within the fusion mass.
Figures 5A, 5B, and 5C: Mid-sagittal CT and MRI of deformity, and 3D CT reconstruction.
Figure 5A: Mid-sagittal CT of deformity.
Figure 5B: Pre-op mid-sagittal MRI
Figure 5C: 3D CT reconstruction of thoracolumbar spine
The patient was diagnosed with developmental thoracolumbar kyphosis, also called congenital dislocation of the spine.
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All posterior single-stage T10 to T12 vertebral column resection with expandable cage reconstruction, and a T7 to L2 posterior spinal fusion.
Screws were placed 2 levels below and 2 above the planned resection, with transverse process hooks at an additional level. We performed a complete spondylectomy from the posterior approach, including both facets, pedicles, and costrovertebral joints at all 3 levels.
Two (T10, T11) very atrophic and chronically compressed nerve roots were sacrificed on the right side for cage insertion. All T10 to T12 vertebral body bone was removed, providing 360° decompression of the spinal cord.
An anterior (deep) soft tissue release off the anterior lips of T9 and L1 was necessary to allow anterior column lengthening. The cage was inserted from the right, and expanded anteriorly while simultaneously compressing minimally contoured rods in the pedicle screws posteriorly. When neutral alignment was reached, we locked both devices. We had abundant autograft from the spondylectomy to pack all around the cage after it was inserted.
Total blood loss was approximately one liter in a 55 kg patient. Total operative time was 4.5 hours from exposure to closure. SSEP and MEP monitoring throughout the case revealed no pre-op or post-op deficits.
Figure 6: On-table, prone long cassette films
Figure 7: Pre-op (left) and post-op AP long cassette films, with minimal scoliosis and shoulder imbalance in the post-op film.
Figure 8: Pre-op (left) and post-op (6 month) x-rays showing deformity correction of approximately 65°, including some settling, and appropriate spinal balance.
Figure 9: Pre-op (left) and post-op clinical pictures
The patient’s measured deformity (T9 to L1) went from 78° to 10° at 6-month follow-up.
The patient is 8 months post-op with no back or leg pain, excellent deformity reduction, and able to walk at any speed without difficulty. He is very happy with his clinical profile.
I would like to commend Drs. Kraemer and Kishan for the successful and safe treatment of this difficult spinal deformity. It is clear that surgical intervention was well indicated in this young man based on the progressive deformity and signs and symptoms of thoracic myelopathy. I feel strongly that continued nonoperative management would have led to continued progression, potentially increasing the risk of surgery in the future. There is no role for bracing or physical therapy for the correction of congenital kyphoscoliosis in this skeletally mature individual.
In patients with severe three-dimensional congenital spinal deformity, preoperative imaging including MRI and 3D CT scan is critical in order to understand vertebral column pathoanatomy prior to surgery. It this case, these studies provide critical information about bone and neural anatomy and help to decrease the risk of neurologic deficit.
The long term success of surgical correction in this case requires restoration of the sagittal profile across the thoracolumbar junction and any option that includes fusion in situ will not address this issue. When weighing surgical options, it is important to note that a surgeon's desire to choose a less technically demanding procedure in this situation may leave the patient with an unacceptable clinical deformity with high risk for continued deformity progression or symptomatic sagittal imbalance potentially requiring an even more complicated revision surgery in the future.
I completely agree with the surgeons' decision to address this deformity through an all posterior vertebral column resection. The surgical treatment of severe spinal deformity has traditionally been based on a circumferential approach to the spinal column performed either as a single day or staged procedure. This approach has been the standard of care of severe spinal deformities for the past few decades. More recently, the posterior vertebral column resection (VCR) technique has obviated the need for a circumferential approach in primary and revision settings. The surgical technique involved in a posterior VCR is quite demanding and requires the operating team to be well versed in spinal deformity surgical techniques; however, an increasing body of literature has shown that a posterior-based VCR is a safe technique to treat severe primary or revision spinal deformities. Recent publications have shown that acceptable spinal deformity correction can be obtained through this all-posterior approach, similar if not superior to patients treated with a circumferential and anterior and separate posterior approach.
When performing these procedures, it is important to emphasize that pedicle screw fixation is critical to provide stability to the spinal column above and below the resection area in order to prevent spinal subluxation as the spine becomes very unstable during the posterior reconstruction. It is critical that a temporary stabilizing rod is placed and attached to at least two or three pedicle screws above and below the resection area before the anterior vertebral body is removed. It has been my preference to obtain at least 6 fixation points above and below the resection in order to maintain spinal stability while fusion occurs. I have also preferred to utilize stainless steel implants with cross-links in these cases, again to maximize the rigidity of the construct which is under considerable stress given the circumferential resection at the time of surgery.
These surgeries have a very high neurologic risk. This is in part due to the severe nature of the deformity, and in part due to the circumferential instability created at the time of surgery in order to correct these deformities. It is imperative to use intraoperative spinal cord monitoring with some form of motor tract monitoring in order to provide early detection of data loss and I routinely use SSEP and TcMEP neuromonitoring as was used in this case.
The surgeons achieved an excellent decompression and correction of deformity as evidence by the clinical photos and post-op x-rays, and the patient has noted improvement in his balance and clinical appearance 8 months after surgery. The patient will need to be followed long term to assess for fusion, and to monitor adjacent segments and maintenance of global balance. I congratulate Drs. Kraemer and Kishan on their excellent treatment of this complicated problem.