General
Lenke-Silva levels of treatment for operative ADS
Level | Neurogenic claudication/ Radiculopathy | Back pain | Ant osteophytes | Olisthesis | Coronal Cobb | Lumbar kyphosis | Global imbalance | Surgical strategy |
0 | Minimal | Minimal | + | <2 mm | <30 | - | - | Non operative management |
1 | + | Minimal | + | <2 mm | <30 | - | - | Decompression alone |
2 | + | + | - | >2 mm | <30 | - | - | Decompression and short fusion |
3 | + | + | - | >2 mm | >30 | - | - | Decompression and lumbar curve instrumented fusion (Involved segment) |
4 | + | + | - | >2 mm | >30 | + | - | Lordosis restoration (decompression with anterior and posterior spinal instrumented fusion) |
5 | + | + | - | >2 mm | >30 | + | + (flexible) | Thoracic instrumentation and fusion extension |
6 | + | + | - | >5 mm | >30 | + | +(stiff/fused) | Osteotomy |
Level I (Decompression Alone):
- Indication
- Clinical presentation:
- Minimal or no back pain and/or deformity complaints.
- Neurogenic claudication due to central stenosis requiring limited decompression.
- Radiographic features:
- Anterior osteophytes should be present.
- Subluxation no more than 2 mm.
- Reasonable sagittal and coronal balance.
- Curve < 30°.
- No thoracic hyperkyphosis or imbalance.
- Surgical technique
- Caution: Decompression alone for stenosis with associated scoliosis can lead to deformity progression and worsening symptoms.
- Study findings (Cheh et al., 2006):
- Level I patients were older and had smaller curves compared to Level II.
- At a minimum 2-year follow-up, 62% of Level I vs. 82% of Level II patients reported good-excellent results (p < 0.05).
- By 5 years of follow-up, Level I patients had a higher rate of recurrent stenosis (12/16) compared to adjacent level stenosis in Level II patients (14/39) (p = 0.008).
Level II (Decompression with Limited Instrumented Fusion):
- Surgical technique
- Decompression and instrumentation limited to the area of decompression.
- Indication
- Suitable for patients with symptoms requiring extensive decompression
- Radiographic features:
- Curves < 30°.
- More than 2 mm of subluxation.
- No anterior osteophytes in the area of decompression.
- Clinical presentation:
- No back pain/deformity symptoms.
- No thoracic hyperkyphosis.
- Relatively well-balanced patient.
- Study findings (Cheh et al., 2006):
- At a minimum 2-year follow-up, 62% of Level I vs. 82% of Level II patients reported good-excellent results (p < 0.05).
- Level II patients had a lower rate of stenosis (adjacent level) compared to recurrent stenosis in Level I patients at 5-year follow-up.
Level III (Instrumented Fusion of Entire Lumbar Curve):
- Surgical technique
- Instrumented fusion of the entire lumbar curve in addition to necessary decompressions.
- Indicated when symptoms of primary back pain are associated with spinal deformity.
- Clinical correlation of pain with the curve location is important for operative treatment selection.
- Typical radiographic features:
- Curves > 45°.
- 2 mm of subluxation.
- Lack of anterior osteophytes in the operative region.
- Reasonable coronal and sagittal balance.
- Anterior spinal fusion (TLIF approach) can be a useful adjunct at the lower end of the construct when fusing to the lumbosacral junction.
Level IV (Anterior and Posterior Fusion of Lumbar Spine):
- Indications
- Clinical features
- Radiographic features:
- No anterior osteophytes.
- No thoracic hyperkyphosis.
- 2 mm of subluxation.
- Surgical technique
- Involves both anterior and posterior fusion of the lumbar spine.
- Anterior spinal fusion plays a significant role in:
- Correcting lumbar hypokyphosis and imbalance.
- Providing indirect decompression via foraminal distraction.
- Decreasing pseudarthrosis (especially in smokers, patients with diabetes, and osteopenic patients).
- Preventing posterior instrumentation failure by load sharing (especially in obese patients).
- Caution: Increased instability from a formal anterior fusion in older patients.
- Selectively recommended for patients with severe stenosis, back pain, and deformity symptoms with mild sagittal imbalance.
Level V (Extension of Fusion into Thoracic Region):
- Surgical technique
- Extending fusion and instrumentation into the thoracic region.
- Where to fuse
- Proximal Fusion Levels:
- Should start at a neutral and stable vertebra, as defined by the center sacral vertical line.
- Should never stop at a rotatory subluxation.
- The thoracic physiological apex must be avoided.
- Therefore, the fusion should stop well below T-10 or well above T5–6.
- Distal Fusion Levels:
- Should begin at a neutral and stable vertebra.
- Should never end at a rotatory subluxation.
- Fusion could end at L-5.
- However, fusion must extend to the sacrum if there is:
- An oblique take-off of L5 on the sacrum (typical with fractional curves > 15°).
- Advanced degeneration of the L5/S1 intervertebral disc.
- L5–S1 spondylolysis.
- Previous decompression at the L5/S1 segment.
- Fusion at T-12 and above should be considered for extension to the ilium/S1.
- Fractional curves > 15° must be included in the distal fusion to achieve balance.
- Osteotomies can be particularly useful in this subgroup of patients.
- Indication
- In patients meeting criteria for Lenke-Silva Level I-IV levels AND
- Thoracic hyperkyphosis and/or thoracic decompensation.
- Global and/or coronal imbalance.
Level VI (Osteotomy):
- Indications
- Rigid deformities
- On lateral bending xrays:
- < 30% curve correction: Curve are stiff → require osteotomy
- > 30% curve correction: Curve are flexible → do not require osteotomies
- Clinically unbalanced patients
- Patients with prior fusions
- Surgical technique
- Osteotomies aim
- Clinically rebalance the patient.
- Decrease the load on instrumentation at the metal-bone interface.
- Sagittal imbalance can be classified as:
- Type I: Globally balanced, but a spinal segment is flat or kyphotic.
- If disc space is mobile enough to allow for extension: Smith-Petersen osteotomies
- If disc space mobility is insufficient
- If bone stock is adequate, anterior releases + morselized graft can be used.
- If bone stock is inadequate, anterior releases + anterior structural grafts are used.
- Type II: Global and segmental imbalance.
- Anterior releases + anterior structural grafts + Smith-Petersen osteotomies
- used when the weight-bearing line within 3 cm of the sacrum.
- Pedicle subtraction osteotomy
- High bone-on-bone contact → high fusion rates.
- Useful in cases of poor bone stock, smokers, and diabetic patients
- Provides ~30° of lordotic correction.
- It is often suitable for global imbalance correction without needing anterior releases or structural grafting.
- Anterior support might be needed when fusing to the sacrum, but current techniques allow for a posterior-only approach.
- The precise amount of bone resection for balance can be calculated using simple trigonometry.
- Combined sagittal and coronal imbalance can be classified as:
- Type A: Shoulders and pelvis tilt in opposite directions.
- Asymmetrical pedicle subtraction osteotomies.
- Type B: Shoulders and pelvis tilt in the same direction.
- More radical vertebral column resection technique.
Made with Bullet