Kenichiro Sakai1, Toshitaka Yoshii2, Takashi Hirai2, Yoshiyasu Arai3, Kenichi Shinomiya4, Atsushi Okawa2. 1. Department of Orthopedic Surgery, Saiseikai Kawaguchi General Hospital, Nishikawaguchi 5-11-5, Kawaguchi, Saitama, 332-8558, Japan. kenitiro1122@gmail.com. 2. Department of Orthopedic Surgery, Tokyo Medical and Dental University, Yushima 1-5-45, Bunky-Ku, Tokyo, 113-8519, Japan. 3. Department of Orthopedic Surgery, Saiseikai Kawaguchi General Hospital, Nishikawaguchi 5-11-5, Kawaguchi, Saitama, 332-8558, Japan. 4. Department of Orthopedic Surgery, Yokohama City Minato Red Cross Hospital, Shinyamashita 3-12-1, Naka-ku, Yokohama, Kanagawa, 231-8682, Japan.
Abstract
PURPOSE: Cervical sagittal balance has received increased attention as an important determinant of radiological and clinical outcomes. However, no prospective studies have compared the impact of cervical sagittal balance between anterior and posterior surgeries. We previously conducted a prospective study comparing anterior decompression with fusion (ADF) and laminoplasty (LAMP) for degenerative cervical myelopathy (DCM) and reported; however, analysis of cervical alignment within the concept of sagittal balance has yet to be performed, because that concept has recently been proposed. This study aimed to review this prospective cohort, specifically focusing on cervical sagittal balance. METHODS: We prospectively performed ADF or LAMP for DCM patients based on the year of enrollment: ADF was performed in odd-numbered years and LAMP in even-numbered years. Cervical lateral X-ray images taken in the neutral standing position were evaluated preoperatively and at a 1-year follow-up. The radiographic measurements included the following: (1) CL (cervical lordosis: C2-7 lordotic angle), (2) CGH (center of gravity of the head)-C7 SVA (sagittal vertical axis), and (3) C7 slope. The clinical results were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score). RESULTS: We analyzed the data for 66 patients (ADF n = 28, LAMP n = 38). While the CL and CGH-C7 SVA in the ADF were unchanged after the operation, those in the LAMP group worsened, especially in patients with preoperative cervical sagittal imbalance. The C7 slopes were not affected by the operation in either group. The postoperative decreases in the CL in the LAMP group correlated with the preoperative CGH-C7 SVA (r = 0.618, P < 0.01), but those in ADF group did not. In patients with preoperative cervical sagittal imbalance (CGH-C7 SVA ≥40 mm), the recovery rate of the C-JOA score in the ADF group was superior to that in the LAMP group (67.3 vs. 39.8 %). In contrast, for patients without cervical sagittal imbalance, the recovery rate of the C-JOA score showed no significant difference between the ADF and LAMP groups (64.5 vs. 58.7 %). CONCLUSIONS: Postoperative cervical sagittal alignment and balance were maintained after ADF but deteriorated following LAMP, especially in patients with preoperative CGH-C7 SVA ≥40 mm. In these patients, neurological recovery after LAMP was unsatisfactory. LAMP is not suitable for degenerative cervical myelopathy patients with preoperative cervical sagittal imbalance.
PURPOSE: Cervical sagittal balance has received increased attention as an important determinant of radiological and clinical outcomes. However, no prospective studies have compared the impact of cervical sagittal balance between anterior and posterior surgeries. We previously conducted a prospective study comparing anterior decompression with fusion (ADF) and laminoplasty (LAMP) for degenerative cervical myelopathy (DCM) and reported; however, analysis of cervical alignment within the concept of sagittal balance has yet to be performed, because that concept has recently been proposed. This study aimed to review this prospective cohort, specifically focusing on cervical sagittal balance. METHODS: We prospectively performed ADF or LAMP for DCMpatients based on the year of enrollment: ADF was performed in odd-numbered years and LAMP in even-numbered years. Cervical lateral X-ray images taken in the neutral standing position were evaluated preoperatively and at a 1-year follow-up. The radiographic measurements included the following: (1) CL (cervical lordosis: C2-7 lordotic angle), (2) CGH (center of gravity of the head)-C7 SVA (sagittal vertical axis), and (3) C7 slope. The clinical results were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score). RESULTS: We analyzed the data for 66 patients (ADF n = 28, LAMP n = 38). While the CL and CGH-C7 SVA in the ADF were unchanged after the operation, those in the LAMP group worsened, especially in patients with preoperative cervical sagittal imbalance. The C7 slopes were not affected by the operation in either group. The postoperative decreases in the CL in the LAMP group correlated with the preoperative CGH-C7 SVA (r = 0.618, P < 0.01), but those in ADF group did not. In patients with preoperative cervical sagittal imbalance (CGH-C7 SVA ≥40 mm), the recovery rate of the C-JOA score in the ADF group was superior to that in the LAMP group (67.3 vs. 39.8 %). In contrast, for patients without cervical sagittal imbalance, the recovery rate of the C-JOA score showed no significant difference between the ADF and LAMP groups (64.5 vs. 58.7 %). CONCLUSIONS: Postoperative cervical sagittal alignment and balance were maintained after ADF but deteriorated following LAMP, especially in patients with preoperative CGH-C7 SVA ≥40 mm. In these patients, neurological recovery after LAMP was unsatisfactory. LAMP is not suitable for degenerative cervical myelopathypatients with preoperative cervical sagittal imbalance.
Authors: Christopher P Ames; Benjamin Blondel; Justin K Scheer; Frank J Schwab; Jean-Charles Le Huec; Eric M Massicotte; Alpesh A Patel; Vincent C Traynelis; Han Jo Kim; Christopher I Shaffrey; Justin S Smith; Virginie Lafage Journal: Spine (Phila Pa 1976) Date: 2013-10-15 Impact factor: 3.468
Authors: Bassel G Diebo; Vincent Challier; Jensen K Henry; Jonathan H Oren; Matthew Adam Spiegel; Shaleen Vira; Elizabeth M Tanzi; Barthelemy Liabaud; Renaud Lafage; Themistocles S Protopsaltis; Thomas J Errico; Frank J Schwab; Virginie Lafage Journal: Spine (Phila Pa 1976) Date: 2016-12-01 Impact factor: 3.468