The Effect of Uncinate Process Resection on Subsidence Following Anterior Cervical Discectomy and Fusion.
10.3340/jkns.2017.0202.014
- Author:
Su Hun LEE
1
;
Jun Seok LEE
;
Soon Ki SUNG
;
Dong Wuk SON
;
Sang Weon LEE
;
Geun Sung SONG
Author Information
1. Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea. md6576@naver.com
- Publication Type:Original Article
- Keywords:
Spondylosis;
Prosthesis failure;
Zygapophyseal joint;
Spinal fusion;
Complication
- MeSH:
Bias (Epidemiology);
Diskectomy*;
Humans;
Linear Models;
Logistic Models;
Methods;
Prosthesis Failure;
Proxy;
Retrospective Studies;
Spinal Fusion;
Spondylosis;
Zygapophyseal Joint
- From:Journal of Korean Neurosurgical Society
2017;60(5):550-559
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: Subsidence is a frequent complication of anterior cervical discectomy and fusion. Postoperative segmental micro-motion, thought to be a causative factor of subsidence, has been speculated to increase with uncinate process resection area (UPR). To evaluate the effect of UPR on micro-motion, we designed a method to measure UPR area based on pre- and postoperative computed tomography images and analyzed the relationship between UPR and subsidence as a proxy of micro-motion. METHODS: We retrospectively collected clinical and radiological data from January 2011 to June 2016. A total of 38 patients (53 segments) were included. All procedures included bilateral UPR and anterior plate fixation. UPR area was evaluated with reformatted coronal computer tomography images. To reduce level-related bias, we converted UPR area to the proportion of UPR to the pre-operative UP area (pUPR). RESULTS: Subsidence occurred in 18 segments (34%) and positively correlated with right-side pUPR, left-side pUPR, and the sum of bilateral pUPR (sum pUPR) (R=0.310, 301, 364; p=0.024, 0.029, 0.007, respectively). Multiple linear regression analysis revealed that subsidence could be estimated with the following formula: subsidence=1.522+2.7×sum pUPR (R2=0.133, p=0.007). Receiver-operating characteristic analysis determined that sum pUPR≥0.38 could serve as a threshold for significantly increased risk of subsidence (p=0.005, area under curve=0.737, sensitivity=94%, specificity=51%). This threshold was confirmed by logistic regression analysis for subsidence (p=0.009, odds ratio=8.471). CONCLUSION: The UPR measurement method confirmed that UPR was correlated with subsidence. Particularly when the sum of pUPR is ≥38%, the possibility of subsidence increased.
