Correction of Chin-on-Chest/Rigid Neck Drop - Cervical Pedicle Subtraction Osteotomy -

Transcription

1 Correction of Chin-on-Chest/Rigid Neck Drop - Cervical Pedicle Subtraction Osteotomy - Sang-Hun Lee MD, PhD Professor, Department of Orthopedic Surgery Kyung Hee University, School of Medicine, Seoul, Korea CERVICAL KYPHOSIS; CLINICAL FINDINGS Limit activities of daily living Eating & drinking, hygiene, respiration Horizontal gaze & social activity Disabling mechanical pain Secondary myelopathy; stretching, ischemia COMPLICATIONS OF CERVICAL SPINE OSTEOTOMY IN THE LITERATURE Overall Cx. rate 26.9 ~ 87.5% Neurological Sx. 8.9~62.5 (permanent 4.3%) ; Radiculopathy, paraplegia, hemiplegia, quadriplegia Mortality rate 2.6% ISSUES ON CERVICAL DEFORMITY CORRECTION Degree of correction Fixation methods Osteotomy techniques Reduction maneuver DEGREE OF CORRECTION Sagittal balance of the cervical spine Cervicothoracic 1

2 : Thoracic inlet angle (TIA), T1 slope, Neck tilting Thoracolumbar: Lumbar lordosis, thoracic kyphosis Spinopelvic: Pelvic incidence, pelvic tilting, sacral slope Chin-brow vertical angle (CBVA) Compromised ability of horizontal gaze in ankylosed spine 10 CBVA : better function for downstairs, reading & writing, eating FIXATION METHODS Types of fixation External fixation: Halo vest Internal fixation: Wiring, plate with screw, lateral mass screw, cervical pedicle screw Extent of fixation O-C, C-T, or O-C-T Variable with fixation strength, level of ankyloses etc. Rod Diameter: 3.2mm, 3,5mm, > 4.0mm, transitional rod Material: Ti (main), CoCr. TYPES OF CERVICAL OSTETOMY Extension osteotomy History Advantages Urist, 1958 : In sitting position, local anesthesia Simmons osteotomy or Smith-Petersen type osteotomy (SPO) 2

3 Technically simple Applicable in multilevel & mid-axial cervical spine (C2-7) Disadvantages Not applicable to complete ankylosed anterior column (Fx. or subluxation risk) Unstable high incidence of delayed translation requires additional external fixation Anterior osteotomy (will be dealt in previous topic) Pedicle subtraction osteotomy Tokala et al. (2007) Advantages Disadvantages Main indications Initial stability : Delayed translation Wider contact surface : better healing of osteotomy Technical difficulty for complete release of 3-column Safe reduction/correction of deformity challenging procedure Complete 3 column ankylosis C-T junctional deformity Need one-stage, large angle correction Combination of the above REDUCTION MANEUVER Why reduction is critical? Complete instability after osteotomy Sudden, uncontrolled fracture Overcorrection, translation or subluxation of spinal column Impingement of spinal cord &/or nerve root History 3

4 Turnbuckle (Urist, 1958) Prebent rod loop with gradual wire tightening (Shimizu, 1996) Malleable rod (Mehdian, 1999) Ilizarov distraction (Bouchard, 2002) Hinged rod (Khoueir, 2008) Sterile Freehand (Lee, 2012) SURGICAL TECHNIQUES OF CERVICAL PSO Positioning Prone position on Jackson operating table mostly preferred Sitting position in severe case Neuromonitoring MEP (±SSEP), EMG Decision of the osteotomy level C7: m/c osteotomy site Get more correction with small amount osteotomy Wide spinal canal Favorably placed spinal cord & nerve root C8 root: More mobile Maximal preservation of U/ext function in case of spinal cord/root injury Vertebral artery; 95% enters into C6 Risk of VA kinking or delayed obstruction 4

5 C6 Extensive ossification of C7 & below More cranial location of the apex of the deformity T1 Associated proximal thoracic deformity High T1 slope The extent of fixation Generally; above 3 + below 3 vertebrae fixation with 3.5mm Ti rod Considering, Osteoporosis Screw fixation strength Ossification of the adjacent segment Release of the deformity Laminectomy + ½ above and ½ below Lateral mass and facet complete resection Locate the cervical nerve roots above and below Pedicle resection ; easier after thinning of the pedicle wall by highspeed burr Decancellation; vertebral body and posterior wall Placement of temporary rod after one side decancellation C6 PSO 5

6 Require release of the vertebral arteries by resection of both ant. tubercles T1 PSO Resection of the proximal 1 st ribs (~ post. Tubercle) to avoid impingement of the C8 and T1 root Correction & fixation Scrub-descrub method - conventional Sterile freehand reduction technique REFERENCES 1. Simmons ED, DiStefano RJ, Zheng Y, et al. Thirty-six years experience of cervical extension osteotomy in ankylosing spondylitis: techniques and outcomes. Spine (Phila Pa 1976) 2006 ; 31 : Tokala DP, Lam KS, Freeman BJC, et al. C7 decancellisation closing wedge osteotomy for the correction of fi xed cervico-thoracic kyphosis. Eur Spine J 2007 ; 16 : Urist MR. Osteotomy of the cervical spine. J Bone Joint Surg Am 1958 ; 40 : Langeloo DD, Journee HL, Pavlov PW, et al. Cervical osteotomy in ankylosing spondylitis: evaluation of new developments. Eur Spine J 2006 ; 15 : Mehdian S, Arun R. A safe, controlled instrumented reduction technique for cervical osteotomy in ankylosing spondylitis. Spine(Phila Pa 1976) 2011 ; 36 : Khoueir P, Hoh DJ, Wang MY. Use of hinged rods for controlled osteoclastic correction of a fi xed cervical kyphotic deformity in ankylosing spondylitis. J Neurosurg Spine 2008 ; 8 : 6

7 Belanger TA, Milam RA IV, Roh JS, et al. Cervicothoracic extension osteotomy for chin-onchest deformity in ankylosing spondylitis. J Bone Joint Surg Am 2005 ; 87 : El Saghir H, Boehm H. Surgical options in the treatment of the spinal disorders in ankylosing spondylitis. Clin Exp Rheumatol 2002 ; 20 : S Samudrala S, Vayman S, Thiayananthan T, et al. Cervicothoracic junction kyphosis: surgical reconstruction with pedicle subtraction osteotomy and Smith-Petersen osteotomy. J Neurosurg Spine 2010 ; 13 : Shimizu K, Matsushita M, Fujibayashi S, et al. Correction of kyphotic deformity of the cervical spine in ankylosing spondylitis using general anesthesia and internal fi xation. J Spinal Disord 1996 ; 9 : Bouchard JA, Feibel RJ. Gradual multiplanar cervical osteotomy to correct kyphotic ankylosing spondylitic deformities. Can J Surg 2002 ; 45 : Kim KT, Lee SH, Son ES et al. Surgical treatment of Chin-on-Pubis deformity in a patient with ankylosing spondylitis. Spine (Phila Pa 1976) 2012;37:E Lee SH, Kim KT, Suk SK, et al. A sterile-freehand reduction technique for corrective osteotomy of fixed cervical kyphosis. Spine (Phila Pa 1976) 2012;37: