Yipeng Li1,2, Jia Li1,2, Feng Wang1,2, Linfeng Wang1,2, Yong Shen3,4. 1. Department of Orthopaedic Surgery, Third Hospital of Hebei Medical University, Shijiazhuang, 050051, People's Republic of China. 2. Key Laboratory of Orthopaedic Biomechanics of Hebei Province, Third Hospital of Hebei Medical University, Shijiazhuang, 050051, People's Republic of China. 3. Department of Orthopaedic Surgery, Third Hospital of Hebei Medical University, Shijiazhuang, 050051, People's Republic of China. docshenyong@163.com. 4. Key Laboratory of Orthopaedic Biomechanics of Hebei Province, Third Hospital of Hebei Medical University, Shijiazhuang, 050051, People's Republic of China. docshenyong@163.com.
Abstract
BACKGROUND: The K-line is a virtual straight line that connects the midpoints of the anteroposterior spinal canal diameter from C2 to C7 on a cervical lateral X-ray film. Patients with cervical ossification of the posterior longitudinal ligament (OPLL), in which the peak of the OPLL exceeds the K-line (K-line [-]), are less likely to experience sufficient decompression after laminoplasty compared with patients for whom the OPLL does not exceed the K-line (K-line [+]). This retrospective study investigated the influence of K-line position relative to the OPLL on intraoperative and hidden blood loss during unilateral open-door laminoplasty for OPLL. METHODS: Data were retrospectively analyzed of 108 patients with OPLL who underwent unilateral open-door laminoplasty between April 2015 and March 2018. Patient cases were categorized as K-line (+) or (-). The evaluated perioperative parameters were haematocrit, haemoglobin, intraoperative and hidden blood loss, surgical time, postoperative drainage, and complications. Radiological parameters included ossification occupancy ratio and C2-7 lordosis. RESULTS: The K-line (+) and K-line (-) groups were statistically comparable with regard to age, gender, body mass index, OPLL classification, medication history, C2-7 lordosis, postoperative haemoglobin and haematocrit, postoperative drainage, hidden blood loss, and complications. The occupying ratio of the K-line (-) group was significantly greater than that of the K-line (+) group (49.5 ± 15.3% cf. 42.3 ± 10.1%; P = 0.006), and the intraoperative blood loss was also significantly higher (286 ± 110.5 mL cf. 205.5 ± 98.3 L, P = 0.003). The hidden blood loss of the K-line (-) group was higher than that of the K-line (+), but not significantly (295.5 ± 112.6 mL cf. 265.6 ± 103.8 mL; P = 0.072). CONCLUSION: Intraoperative and hidden blood loss associated with unilateral open-door laminoplasty can be predicted by the spatial relationship of the K-line and osteophyte. This relationship is a simple and practical index that may help surgeons determine the appropriate surgical strategy for patients with OPLL.
BACKGROUND: The K-line is a virtual straight line that connects the midpoints of the anteroposterior spinal canal diameter from C2 to C7 on a cervical lateral X-ray film. Patients with cervical ossification of the posterior longitudinal ligament (OPLL), in which the peak of the OPLL exceeds the K-line (K-line [-]), are less likely to experience sufficient decompression after laminoplasty compared with patients for whom the OPLL does not exceed the K-line (K-line [+]). This retrospective study investigated the influence of K-line position relative to the OPLL on intraoperative and hidden blood loss during unilateral open-door laminoplasty for OPLL. METHODS: Data were retrospectively analyzed of 108 patients with OPLL who underwent unilateral open-door laminoplasty between April 2015 and March 2018. Patient cases were categorized as K-line (+) or (-). The evaluated perioperative parameters were haematocrit, haemoglobin, intraoperative and hidden blood loss, surgical time, postoperative drainage, and complications. Radiological parameters included ossification occupancy ratio and C2-7 lordosis. RESULTS: The K-line (+) and K-line (-) groups were statistically comparable with regard to age, gender, body mass index, OPLL classification, medication history, C2-7 lordosis, postoperative haemoglobin and haematocrit, postoperative drainage, hidden blood loss, and complications. The occupying ratio of the K-line (-) group was significantly greater than that of the K-line (+) group (49.5 ± 15.3% cf. 42.3 ± 10.1%; P = 0.006), and the intraoperative blood loss was also significantly higher (286 ± 110.5 mL cf. 205.5 ± 98.3 L, P = 0.003). The hidden blood loss of the K-line (-) group was higher than that of the K-line (+), but not significantly (295.5 ± 112.6 mL cf. 265.6 ± 103.8 mL; P = 0.072). CONCLUSION: Intraoperative and hidden blood loss associated with unilateral open-door laminoplasty can be predicted by the spatial relationship of the K-line and osteophyte. This relationship is a simple and practical index that may help surgeons determine the appropriate surgical strategy for patients with OPLL.
Entities:
Keywords:
Hidden blood loss; Intraoperative blood loss; K-line; Ossification of the posterior longitudinal ligament; Unilateral open-door laminoplasty
Authors: Christian D Cerecedo-Lopez; Ian Tafel; Asad M Lak; John Chi; Yi Lu; Michael Groff; Hasan A Zaidi Journal: J Clin Neurosci Date: 2019-12-26 Impact factor: 1.961