Iizuka Haku, Iizuka Yoichi, Mieda Tokue, Kobayashi Ryoichi, Nishinome Masahiro, Ara Tsuyoshi, Sorimachi Yasunori, Nakajima Takashi, Takagishi Kenji
Department of Orthopedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
Clin Spine Surg. 2017 Jun;30(5):E598-E602. doi: 10.1097/BSD.0000000000000277.
Retrospective study.
The purpose of this study was to investigate the incidence of subaxial subluxation (SAS) after atlanto-axial arthrodesis in rheumatoid arthritis (RA) patients using annual radiographs obtained for 5 years and clarify the characteristics of SAS after surgery.
Rheumatoid SAS has been reported to occur after atlanto-axial arthrodesis. Many authors have noted that excessive correction of the atlanto-axial angle (AAA) results in a decrease in subaxial lordosis, thereby inducing SAS; therefore, we paid special attention to acquiring a suitable AAA in patients with atlanto-axial arthrodesis.
Twenty-five patients with AAS treated with surgery were reviewed. In all patients, lateral cervical radiographs were obtained in neutral, maximal flexion, and maximal extension positions every year for 5 years after surgery. We investigated the occurrence and progression of SAS using these annual radiographs.
There were no significant differences between preoperative and postoperative value in AAA and subaxial angle (SAA), respectively. Before surgery, SAS was found in 10 patients. The occurrence and progression of SAS after surgery was found in 12 cases (SAS P+ group). There were no significant differences in age, sex, or the duration of RA between the SAS P+ group and the remaining 13 cases. We also found no differences in the preoperative and postoperative AAA and SAA between the 2 groups.
Although SAA was maintained after atlanto-axial arthrodesis in RA-AAS patients, 12 of 25 patients (48%) with AAS developed SAS after atlanto-axial fusion. Further surgery was not needed for SAS up to 5 years after the initial surgery. We did not find any relationship between the occurrence of SAS and the AAA and SAA before and after surgery. Therefore, our findings suggest that proper reduction of AAA in patients with atlanto-axial arthrodesis does not affect the occurrence of SAS at 5 years after surgery.
回顾性研究。
本研究旨在利用连续5年获得的年度X线片，调查类风湿关节炎（RA）患者寰枢关节融合术后下颈椎半脱位（SAS）的发生率，并阐明术后SAS的特征。
类风湿性SAS已被报道发生在寰枢关节融合术后。许多作者指出，寰枢角（AAA）过度矫正会导致下颈椎前凸减少，从而诱发SAS；因此，我们在寰枢关节融合术患者中特别注意获得合适的AAA。
对25例行手术治疗的AAS患者进行回顾性分析。所有患者在术后5年内每年在中立位、最大屈曲位和最大伸展位拍摄颈椎侧位X线片。我们利用这些年度X线片调查SAS的发生和进展情况。
AAA和下颈椎角（SAA）的术前和术后值分别无显著差异。术前，10例患者发现有SAS。术后发现12例（SAS P+组）出现SAS并进展。SAS P+组与其余13例患者在年龄、性别或RA病程方面无显著差异。我们还发现两组之间术前和术后的AAA和SAA无差异。
尽管RA-AAS患者寰枢关节融合术后SAA得以维持，但25例AAS患者中有12例（48%）在寰枢融合术后发生了SAS。初次手术后5年内，SAS无需进一步手术治疗。我们未发现SAS的发生与手术前后的AAA和SAA之间存在任何关系。因此，我们的研究结果表明，寰枢关节融合术患者适当矫正AAA不会影响术后5年SAS的发生。
