个体化股骨头导板在髋关节表面置换术中应用的实验研究

目的 探讨个体化股骨头导板在人工髋关节表面置换术中应用的可行性和安全性。方法 2019 年 1-5 月,选取昆明医科大学解剖学教研室提供的17具成人骨盆标本,其中男 9 具、女 8具,年龄40～70岁,身高155～165 cm。每具骨盆标本按侧别分为导板组(左侧)和对照组(右侧)。导板组基于标本CT轴位扫描数据计算出股骨颈的解剖轴线,设计并制作出与股骨颈部表面解剖形态一致的导板,利用导板辅助定位针置入标本。对照组采用传统股骨头假体定位方法置入定位针。术后行X线摄片和CT扫描,观察定位针与股骨头中心、股骨颈解剖轴线的位置关系,判断股骨头定位针有无内外翻和前后倾。测量对比术前股骨颈干角(NSA)和术后定位针柄干角(SSA)、侧方偏移角、水平偏移角,来评价导板辅助手术的准确性。结果 (1)在导板组中,术中股骨头导板与股骨颈部贴附紧密,稳定性好,能够辅助定位针顺利置入。术后CT、X线摄片显示,17例标本定位针均经过股骨头中心、股骨颈解剖中心。相对于股骨颈解剖轴线,正位X线片显示15例外翻、1例内翻、1例平行,侧位X线片显示14例平行、2例前倾、1例后倾。(2)对照组术后CT显示,12例标本定位针经过股骨头中心、股骨颈解剖中心。正位X线片显示,定位针12例经过股骨头中心、股骨颈解剖中心,相对于股骨颈解剖轴线,12例外翻、2例内翻、3例平行;侧位X线片显示,定位针15例经过股骨头中心、股骨颈解剖中心,相对于股骨颈解剖轴线,10例平行、5例前倾、2例后倾。(3)术前NSA和术后定位针SSA、侧方偏移角、水平偏移角,导板组分别为133.1°±3.52°、138.0°±4.1°、5.2°±2.1°、4.6°±2.3°,对照组分别为133.7°±3.4°、144.3°±5.6°、13.0°±1.7°、8.2°±2.9°,两组间比较,术前NSA差异无统计学意义(P＞0.05)。术后导板组SSA、侧方偏移角、水平偏移角均小于对照组,差异均有统计学意义(t=4.307、14.280、3.520,P值均＜0.05)。结论 个体化股骨头导板应用于髋关节表面置换术中,能为股骨头假体的精确定位、定向置入提供辅助作用。

Pilot research of custom-made navigational template of femoral head in total hip resurfacing arthroplasty

Objective To explore the feasibility and safety of custom-made navigational template of femoral head in total hip resurfacing arthroplasty (THRA).Methods Seventeen adult pelvic specimens were selected from the Department of Anatomy at Kunming Medical University from January 2019 to May 2019, including 9 males and 8 females, with age range of 40-70 years and height of approximately 155-165 cm. Each pelvic specimen was divided into the guide plate group (left) and the control group (right). In the guide plate group, the CT data of the cadaver specimens were preprocessed and calculated to obtain the anatomical axis of the femoral neck. A navigational template consistent with the anatomical shape of the femoral neck was designed. The accuracy and validity were evaluated using a positioning needle, which was used to assist the cadaver implantation experiment. In the control group, the positioning needle was implanted using the traditional technique. Postoperative X-ray and CT images were used to observe the location (varus, valgus, forward, or backward) of the positioning needle at the center of the femoral head and the anatomical axis of the femoral neck. The preoperative femoral neck stem angle (NSA), the postoperative shaft stem angle (SSA), the lateral migration angle, and the horizontal migration angle were measured to evaluate the accuracy of the custom-made navigational template.Results (1) In the guide plate group, the navigational template was attached to the femoral neck of the specimen with good anastomosis; it could assist the needle implant to the desired position. Postoperative CT and X-ray images showed that all the positioning needles passed through the center of the femoral head and the anatomical center of the femoral neck. Compared with the axis of the femoral neck, 15 cases were inverted, one case was varus, and one case was parallel based on the anteroposterior X-ray. On the lateral X-ray, 14 cases were parallel, 2 cases of forward inclination, 1 case was backward inclination. (2) In the control group, 12 cases of the needles passed through the center of the femoral head and the femoral neck based on the postoperative CT scans and anteroposterior X-ray. In addition, 12, 2, and 3 cases were found to be inverted, varus, and parallel by the anteroposterior X-ray. Fifteen cases of the needle passed through the center of the femoral head and the anatomical axis of the femoral neck, and 10 cases were parallel, 5 cases were forward inclination, and 2 cases were backward inclination based on the lateral X-ray. (3) The preoperative NSA, postoperative SSA, lateral migration angle, and horizontal migration angle were 133.1° ± 3.52°, 138.0° ± 4.1°, 5.2° ± 2.1°, and 4.6° ± 2.3° in the guide plate group, respectively, and 133.7° ± 3.4°, 144.3° ± 5.6°, 13.0° ± 1.7°, and 8.2° ± 2.9° in the control group, respectively. No statistically significant difference was found in the preoperative NSA between the two groups (P>0.05). The postoperative SSA, lateral migration angle, and horizontal migration angle in the guide plate group were less than those in the control group, and a statistically significant difference was observed (t=4.307, 14.280, and 3.520, respectively, all P values<0.05).Conclusions Custom-made navigational template of the femoral head could provide accurate navigation for the position and orientation of the femoral head prosthesis in THRA.