Distraction, Compression, Extension, and Reduction Combined With Joint Remodeling and Extra-articular Distraction: Description of 2 New Modifications for Its Application in Basilar Invagination and Atlantoaxial Dislocation: Prospective Study in 79 Cases

摘要

BACKGROUND:Recent strategies for treatment of basilar invagination (BI) and atlantoaxial dislocation (AAD) are based on simultaneous posterior reduction and fixation.OBJECTIVE:To describe new modifications of the procedure distraction, compression, extension, and reduction (DCER), ie, joint remodeling (JRM) and extra-articular distraction (EAD) in patients with vertical joints, and to quantify the improvement in joint indices, ie, sagittal inclination (SI), craniocervical tilt (CCT), and coronal inclination.METHODS:Prospective study (May 2010 to September 2014). Joint indices measured included (normal values): SI (87.15 5.65 degrees), CCT (60.2 9.2 degrees), and coronal inclination (110.3 4.23 degrees). Surgical procedures included DCER alone (performed in SI <100 degrees, group I) or JRM with DCER (in SI: 100-160 degrees, group II), or EAD with DCER in severe BI with almost vertical joints (SI >160 degrees, group III).RESULTS:Seventy-nine patients were selected (mean, 22.5 years of age). All conventional indices improved significantly (P < .001). CCT improved in all groups (P < .01); group I (n = 32): 54 8.7 degrees (preoperative 80.71 12.72 degrees); group II (n = 40): 58 7.0 degrees (preoperative 86.5 14 degrees); group III (n = 7): 62 10.0 degrees (preoperative 104 11.2 degrees). SI improved in both group I and II, P < .01 (cannot be measured in group III). At long-term follow-up (n = 64, 29 8 months, range 12-39 months), the Nurick grade improved to 1.5 +/- 0.52 (preoperative: 3.4 +/- 0.65; P < .001).CONCLUSION:DCER seems to be an effective technique in reducing both BI and AAD. JRM and EAD with DCER are useful in moderate to severe BI and AAD (with SI >100 degrees). Joint indices provide useful information for surgical strategy and planning.ABBREVIATIONS:AAD, atlantoaxial dislocationBI, basilar invaginationCCT, craniocervical tiltCI, coronal joint inclinationCVJ, craniovertebral junctionDCER, distraction, compression, extension, and reductionEAD, extra-articular distractionJRM, joint remodelingSI, sagittal inclination