Adult Spinal Deformity Planning Your Osteotomy Eric Klineberg, MD Assistant Professor Department of Orthopaedics UC Davis Surgical Management of Adult Spinal Deformity February 16, 2013 CA#11020A ; DJ#10986A CA#11020A ; DJ#10986A

I have no financial interest with any company regarding this subject Speaking: AO, DePuy Synthes Spine Fellowship Funding: DePuy Synthes Spine, OREF Grants: AO Foundation I have no financial interest with any company regarding this subject Eric Klineberg, MD CA#11020A ; DJ#10986A CA#11020A ; DJ#10986A 2

Lecture Outline Patient and Surgeon analysis Identify the problem Identify the solution Execute Deal with complications CA#11020A ; DJ#10986A

Surgical Decision Making Patient medical status Surgeon experience Minor or Major deformity Gradual or sharp kyphosis Prior fusion Flexability

Patient Factors Age Prior surgery Co-Morbidities Diabetes, HTN, Cardiac dz (stents, MI etc…) Modifiable risk factors: Obesity Smoking Osteoporosis

Obesity Increasing size, makes surgical exposure more difficult More blood loss Risk for PE, poor mobilization Need to have threshold for BMI Patients can meet us “half way”

Smoking Nicotine has been shown to decrease wound and bone healing Even with new biologics I am very aggressive getting patients to stop: CHANTIX®, WELLBUTRIN® Can check urine nicotine levels All patients will try to stop, but few actually will. However even a modest decrease can be helpful

Osteoporosis This is becoming the largest problem in my practice! Bisphosponates, Calcitonin, estrogen replacement. DEXA on all pre-op patients for baseline T < -3.0 will try to initiate FORTEO® (PTH analog) Only medication that increases bone formation Expensive and can be difficult without prior failure

Surgeon Factors Experience, experience, experience! Location, location, location! Help available New practice, don’t want complications! Setting: academic, private, in-between What does your hospital have for you? Bed, equipment, rep, implants, (unanticipated implants), ICU, residents, fellows, NP, PA

Osteotomies in the posterior-only treatment of complex adult spinal deformity: a comparative review. Dorward, IG, Lenke, LG, JNS Mar 2010

Adult Scoliosis What radiographic parameters do we need to consider when evaluating a scoliosis patient? What makes a difference for our patients?

Common Radiographic Findings Use similar measurements as for pediatric population Are we missing out on adult deformity? Emphasis on pelvic alignment Pelvic and spinal miss-alignment

Radiographic Measurements Coronal Cobb angles CSVL Major and Minor curves Sagittal Sagittal vertical axis (SVA)

Radiographic Measurements PI LL TK SVA Pre-operative and post-operative sagittal spino-pelvic parameters Measurements: SVA, L1-S1 Lordosis, T4-T12 Thoracic Kyphosis,

Normal Values Mean Lumbar Lordosis = 40-60° Mean Thoracic Kyphosis = 10-40° Avg normal SVA = < ± 2.5 cm Recently Schwab et al. have talked about Center of Gravity line

Radiographic Measurements PT LL TK Pelvic Measurements: Pelvic Tilt Pelvic Incidence This is pelvic morphology, it does not change Pelvic MisMatch Pelvic Incidence – Lumbar Lordosis

Radiographic Measurements Pelvic MisMatch Pelvic Incidence – Lumbar Lordosis To maintain balance want PI-LL = 10deg

Radiographic Measurements Pelvic MisMatch Pelvic Incidence – Lumbar Lordosis Increased PI leads to Increased LL

Radiographic Measurements Pelvic MisMatch Pelvic Incidence – Lumbar Lordosis Decreased PT leads to Decreased LL Pelvic Tilt Increases

Radiographic Measurements With Deformity

Radiographic Measurements With Deformity Positive SVA

Radiographic Measurements With Deformity Positive SVA Decreased PT Pelvic retroversion Decreased LL PI-LL

Radiographic Measurements With Deformity Positive SVA Decreased PT Pelvic retroversion Decreased LL PI-LL Decompensated Deformity

Common Radiographic Findings Three commons findings: L3–L4 rotatory subluxation, L4–L5 tilt L5–S1 disc degeneration Bridwell et al 2002

Adult Scoliosis Restoration of the sagittal plane in the setting of adult deformity surgery is critical to achieving long term clinical success. Glassman et al suggested that a positive sagittal balance was the most reliable predictor of clinical symptoms in adult deformity patients. Schwab et al demonstrated that focal obliquity and loss of lumbar lordosis were significantly correlated with pain and negative outcomes. Glassman SD, et al. Correlation of radiographic parameters and clinical symptoms in adult scoliosis. Spine 2005;30:682–8. Schwab FJ, et al. Adult scoliosis: a quantitative radiographic and clinical analysis. Spine 2002;27:387–92

Adult Scoliosis Pelvic tilt defines the amount of pelvic retroversion and has been implicated as an important factor on postoperative residual pain. Lazennec at el described a decrease in residual pain with lower pelvic tilt, indicating less retroversion and potentially less pelvic compensation. This concept was more clearly defined by Lafage et al, and a pelvic tilt of less then 25 degrees was established as optimal. Lazennec JY, et al. Sagittal alignment in lumbosacral fusion Eur Spine J 2000;9:47–55. Lafage V, et al. Pelvic tilt and truncal inclination: two key radiographic parameters Spine. 2009 Aug 1;34(17):E599-606.

Classification System AIS classification system (King & Lenke) cannot be applied. These are different curves Stiffer, degenerative processes Often have clinical symptoms at presentation natural history is different Recently, SRS developed classification for adult deformity.

ASD Classification

SRS Classification for Adult Deformity Curve Type Defines the primary deformity Modifiers PI-LL: miss-match Pelvis defines what is needed PT: amount of compensation Compensatory retroversion SVA: amount of global decompensation Marker of overall decompensation (does not take into account cervical spine)

Spine Balance Most important principle in the surgical treatment of adult scoliosis Achieve & maintain proper sagittal & coronal balance Head placed over the pelvis.

Spine Balance A balanced spinal posture provides for decreased energy requirements with ambulation limits pain and fatigue improves cosmesis and patient satisfaction limits complications associated with unresolved (or new) deformities

SVA = 11 LL=+31 TK=0

SVA = 11 LL=+31 TK=0 PT = 26 PI = 60 Mismatch = 60 - +31 = 91

Osteotomies in the posterior-only treatment of complex adult spinal deformity: a comparative review. Dorward, IG, Lenke, LG, JNS Mar 2010

How to Achieve Correction Surgical planning Determine ammout of correction needed Flexibility of the curves Prone films, exam, CT/MRI

How to Achieve Correction Posterior Facetectomy, Ponte, osteotomy, vertebral column resection Anterior Discectomy, and interbody Lateral Discectomy ALL release

How do I decide Determine flexibility If flexible – posterior only If fused – osteotomy If stiff Good LL (20-30) posterior only Poor LL – anterior posterior (particularly with High PT)

Anterior/Posterior Lateral ALL release Usually for adjacent level disease with prior fusion Flat back deformity

Anterior/Posterior Lateral ALL release Usually for adjacent level disease with prior fusion Flat back deformity

SVA = 11 PT = 25 LL=+31 TK=0 PI = 60

Goal To Achieve normal alignment: SVA < 4cm PT = 20 PI-LL = 10 Need 70 deg of lordosis at end + starting at 30 degrees positive, and has high pelvic tilt Need more then 90 degrees of correction! Formal Anterior/Posterior

SVA = 0 PT = 14 LL=67 TK=40 PI = 60 PI-LL = 10

Technique Positioning Prone (I use open frame, OSI table) Arms are up, may put arms at side for high Costotransversectomy (>T4) Neuro-monitoring is a must! Wide prep for possible Chest tube if you enter pleural space during dissection

Ponte/Smith-Petersen Osteotomy History In 1945, Smith-Petersen et al. reported the first spinal osteotomy. Most studies reported the correction in ankylosing spondylitis patients with osteoclasis Ponte described similar bone resection and mobility through an open disc space

Ponte/Smith-Peterson Osteotomy SPO allows for 10° per level Remove supraspinous, intraspinous, and ligamentum flavum with facetectomy to produce a posterior release. Ensure exiting nerves are decompressed Posterior compression of the osteotomy brings about kyphosis correction

Osteotomy The overall effect is similar to a Smith-Peterson Osteotomy CA#11020A ; DJ#10986A

Anterior release, combined with SPO

Pedicle Subtraction Osteotomy History Pedicle subtraction osteotomy was first described by Thomasen in 1985 This is an extension of the SPO, and involves resection of the posterior elements and vertebral body Particularly useful when anterior approach is not possible

Pedicle Subtraction Osteotomy Typically performed in the lumbar spine Larger correction Can shorten cauda Less often in cervical and thoracic spine Bony resection determines final alignment

PSO Set up Neuromonitoring Measure pre-op, must include pelvic parameters Plan, plan , plan Expect blood loss: Cell saver, coagulant (TXA, Amicar), blood products

PSO - Technique Exposure Careful with blood loss Place screws first If excessive bleeding (>2L, before PSO, plan on staging) Instrumentation removal etc…

PSO - Technique Decompress level that you need – L3 Often scar tissue etc… Remove Lamina above at minimum for adequate exposure (L2-3) Identify exiting nerves at level (L3) and level above (L2) Dissect pedicle to pedicle (L2-4)

PSO - Technique +/- remove transverse process Remove body first Then lateral body (I dissect laterally using cobb, and place malleable retractor) Medial pedicle and posterior body is last MUST remove all posterior body (will cause neurologic injury)

PSO - Technique Over contour rods Multiple techniques: 4 rod Cantilever bend Bed reduction

PSO - Technique Dura will buckle Verify nerves are free in new foramen Feel under the dura Check signals

Vertebral Column Resection History VCR was first described in 1922 by MacLennan, who performed an apical resection from a posterior-only approach with postoperative casting for the treatment of severe scoliosis In 1983, Luque presented eight cases of vertebrectomy in patients with a primary spinal deformity > 90° In 2002, Suk et al. developed the posterior-only approach for VCR (PVCR)

Where are we trying to go? Costotransversectomy and VCR provide both access to the vertebral column in the thoracic spine Costotransversectomy allows for access on usually one side to proved decompression of the neural structures VCR is usually a costo that is expanded to both sides to destabilize the spine and allow for coronal and sagittal re-alignment

Thoracic Vertebrae Osseous anatomy Spinous process Lamina Pedicle Pars Transverse Process Rib Articluations What Vertebra does the T9 rib articulate with?

Thoracic Vertebrae Critical to understand the rib articulation: Ribs articulate with the transverse process of their vertebra, as will as the body of their vertebra, and the level above. Therefore to get access to both disc levels you usually need to take two ribs…

Rib Articluation Thoracic Surgery Clinics Volume 17, Issue 4, November 2007, Pages 473–489

Spinal Cord Spinal Cord Intercostal Nerve

Neurovascular Bundle Neurovascular bundle runs on the inferior aspect of the rib in the neurovascular groove

Technique Positioning Prone (I use open frame, OSI table) Arms are up, may put arms at side for high Costotransversectomy (>T4) Neuro-monitoring is a must! Wide prep for possible Chest tube if you enter pleural space during dissection

Case Example 31 yo female Biopsy diagnosis of metastatic gastric CA c/o back pain and LE parasthesia PE: pathologic clonus, hyper-reflexia, pain with back percussion

Case T9 T9 T11

Technique Perform standard midline approach Dissection carried out to TP on both sides Extend dissection laterally on planned Costotransversectomy side – need 6-8cm of ribs Place all pedicle screws Temporary rod

Technique Laminectomy Can be unilateral, but I usually perform full laminectomty for better visualization Ligate exiting root from foramen (use ties on both sides and leave long)

Technique Will need to take two ribs Preserve intercostal artery and vein if possible Use periosteal to separate pleura and NVB from rib Disarticulate ribs from TP and vertebra Then remove TP and pedicle

Technique Place retractor to ventral surface of vertebra Identify disc space (use rib head) Nerve ties can be used for gentle retraction

Technique Proceed with vertebra decompression Start with body first identify disc space and work towards the middle. Medial bony ledge is taken last Watch out for epidurals

Technique Leave ALL and anterior vertebra wall (protection) Place corpectomy device Compress with posterior instrumentation

Intra-Operative

Post-Operative

Surveillance CT

Costotransversectomy Complications: Pleural Tear Chest tube vs red-rubber catheter (I usually place Chest Tube) Dural Tear Primary repair, if not possible, may need shunt

Vertebral Column Resection Costotransversectomy on both sides May need to resect both nerve roots May want to clamp intercostal artery if you need to ligate (adamkiewitcz)

Technique (stole from AONA) Midline Incision Laminectomy Resection of posterior rib, TP, Facet Sacrifice of nerve roots CA#11020A ; DJ#10986A 87

Technique (stole from AONA) Temporary Rod Corpectomy Kyphocorrection CA#11020A ; DJ#10986A 88

Technique (stole from AONA) Definitive Rods Compression across cage CA#11020A ; DJ#10986A 89

Tips and Tricks Neuromonitoring is a must! Be careful with shortening the spinal column Use cage (+/- expandable) Translation causes paralysis! Keep anterior column intact, do not remove ALL and eggshell anterior cortex (like PSO)

Tips and Tricks Nerve root ties can be used at gentle retractors Use rib head to define the disc space Work from disc space to disc space Prep wide for possible chest tube (warn patient ahead of time) Pre-operative planning is the key measure twice and cut once.

Thank You CA#11020A ; DJ#10986A 95