胫骨后倾角在膝关节置换术后的改变及意义

Change and clinical significance of posterior slope of tibial plateau after total knee arthroplasty

[目的]对因骨性关节炎行全膝关节置换术（total knee arthroplasty,TKA）术后膝关节功能恢复优良的患者,测量评价术前、术后胫骨（假体）平台后倾角（PSA）,为TKA中胫骨平台截骨提供参考数据。[方法]采用回顾性研究,对本院2007年1月~2009年3月因骨性关节炎行TKA治疗的30膝24例术后HSS评分70分以上的患者,收集术前、术后X线侧位片的医学数字影像通信标准DICOM格式的相片,测量髓内、髓外胫骨（假体）平台后倾角。[结果]髓内参照法,术前胫骨内、外侧平台及术后假体后倾角分别为13.1°±3.3°,9.8°±3.5°,5.1°±2.3°,三者两两之间均有显著性差异（P〈0.05）。髓内、髓外参照法之间也有显著性差异（P〈0.05）。髓内参照法,术后假体后倾角和5°后倾截骨标准无显著性差异（P〉0.05）。[结论]术前、术后胫骨平台后倾角不同,术中胫骨截骨应符合髓内参照法5°或髓外参照法8°后倾截骨标准,以恢复包括关节软骨、半月板在内的后倾角度,获得更好的术后功能。

[ Objective] To measure and evaluate the preoperative and postoperative posterior slope angles （ PSA ） of tibial plateau （ or prosthesis ） in patients with osteoarthritis who had a good recovery of joint function after total knee arthroplasty （TKA）, for providing parameters of tibial osteotomy during the total knee arthroplasty. [ Methods ] A retrospective study was conducted on 30 osteoarthritic knees of 24 patients whose hospital for special surgery knee scores （HSS） were above or equal to 70 after TKA from January 2007 to March 2009, to collect the digital photos of knee＇s lateral radiographs in digital imaging and communications in medicine standard （DICOM） format and measure the intramedullary as well as extramedullary posterior slope angle. [ Results] Using intramedullary method, the preoperative posterior slopes of the medial plateau and the lateral plateau were measured as 13.1° ± 3.3°, and 9.8° ±3.5°, respectively. The postoperative posterior slope of the prosthesis was 5.1°± 2. 3°. Pairwise comparison judgments were statistically significant （ P 〈 0. 05 ） . The posterior slope angles were also statistically significant between intramedullary and extramedullary methods （ P 〈 0. 05 ） . According to the intramedullary guide, the difference of the posterior slopes between prosthesis and 5° posterior sloped cutting standard was not statistically significant. [ Conclusion] The postoperative posterior slope angle is not similar to the preoperative one. The cutting of the proximal tibial in TKA should be at a 5° following intramedullary guide standard or at a 8° following extramedullary guide standard posterior slope, thereby obtaining better joint function after operation.