title: Dropped head syndrome after cervical laminoplasty: A case control study.
abstract: Dropped head syndrome (DHS) is characterized by apparent neck extensor muscle weakness and difficulty extending the neck to raise the head against gravity. The aim of the present study was to elucidate possible risk factors for DHS after cervical laminoplasty. Five patients who developed DHS after cervical laminoplasty (DHS group) and twenty age-matched patients who underwent laminoplasty without DHS after surgery (control group) were compared. The surgical procedure was single-door laminoplasty with strut grafting using resected spinous processes or hydroxyapatite spacers from C3 to C6 or C7. Analyses of preoperative images including the C2-C7 angle, C7-T1 kyphosis, T1 tilt, center of gravity line from the head-C7 sagittal vertical axis (CGH-C7 SVA) were performed on lateral plain cervical spine radiographs. Preoperative T2-weighted MRI at the C5 vertebral level was used to measure the cross-sectional area of the deep extensor muscles. Widths of the lateral gutters were assessed postoperatively using CT scans of the C5 vertebral body. The average preoperative C2-C7 angle was significantly smaller in the DHS group compared with the control group. The average preoperative C7-T1 angle was significantly larger in the DHS group compared with the control group. The average preoperative CGH-C7 SVA was significantly larger in the DHS group compared with the control group. In conclusion, patients with more pronounced preoperative C2-C7 kyphosis, C7-T1 kyphosis, and CGH-C7 SVA are more likely to develop DHS following laminoplasty.
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan. Electronic address: masaokod@gmail.com.
authors.forename: Masao
authors.initials: M
authors.lastname: Koda
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Furuya
authors.affiliation: Department of Orthopedic Surgery, Narashino Dai-Ichi Hospital, Narashino, Chiba 275-0016, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Kinoshita
authors.affiliation: Department of Orthopedic Surgery, Matsudo City Hospital, Matsudo, Chiba 271-8511, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Miyashita
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Ota
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Maki
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ijima
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Junya
authors.initials: J
authors.lastname: Saito
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Orthopedic Surgery, University of Tsukuba, Bunkyo, Tokyo 112-0012, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Department of Orthopedic Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba 299-0111, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Aramomi
authors.affiliation: Department of Orthopedic Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba 299-0111, Japan.
authors.forename: Chikato
authors.initials: C
authors.lastname: Mannoji
mesh_terms: D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000601:surgery; D065406:Laminoplasty / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging / Q000009:adverse effects; D008297:Male; D018908:Muscle Weakness / Q000209:etiology* / Q000503:physiopathology; D009135:Muscular Diseases / Q000209:etiology* / Q000503:physiopathology; D009334:Neck Muscles / Q000503:physiopathology*; D011183:Postoperative Complications; D011184:Postoperative Period; D012307:Risk Factors
keywords: Cervical deformity; Cervical sagittal imbalance; Corrective surgery; Dropped head syndrome; Laminoplasty