Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois, USA.
Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Ililnois, USA.
Bone Joint J. 2018 Jul;100-B(7):862-866. doi: 10.1302/0301-620X.100B7.BJJ-2017-1607.R1.
Accurate placement of the acetabular component is essential in total hip arthroplasty (THA). The purpose of this study was to determine if the ability to achieve inclination of the acetabular component within the 'safe-zone' of 30° to 50° could be improved with the use of an inclinometer.
We reviewed 167 primary THAs performed by a single surgeon over a period of 14 months. Procedures were performed at two institutions: an inpatient hospital, where an inclinometer was used (inclinometer group); and an ambulatory centre, where an inclinometer was not used as it could not be adequately sterilized (control group). We excluded 47 patients with a body mass index (BMI) of > 40 kg/m, age of > 68 years, or a surgical indication other than osteoarthritis whose treatment could not be undertaken in the ambulatory centre. There were thus 120 patients in the study, 68 in the inclinometer group and 52 in the control group. The inclination angles of the acetabular component were measured from de-identified plain radiographs by two blinded investigators who were not involved in the surgery. The effect of the use of the inclinometer on the inclination angle was determined using multivariate regression analysis.
The mean inclination angle for the THAs in the inclinometer group was 42.9° (95% confidence interval (CI) 41.7° to 44.0°; range 29.0° to 63.8°) and 46.5° (95% CI 45.2° to 47.7°; range 32.8° to 63.2°) in the control group (p < 0.001). Regression analysis identified a 9.1% difference in inclination due to the use of an inclinometer (p < 0.001), and THAs performed without the inclinometer were three times more likely to result in inclination angles of > 50° (odds ratio (OR) 2.8, p = 0.036). The correlation coefficient for the interobserver reliability of the measurement of the two investigators was 0.95 (95% CI 0.93 to 0.97).
The use of a simple inclinometer resulted in a significant reduction in the number of outliers compared with a freehand technique. Cite this article: Bone Joint J 2018;100-B:862-6.
在全髋关节置换术中（THA），髋臼部件的准确放置是至关重要的。本研究的目的是确定在使用倾斜计的情况下，髋臼部件的倾斜度是否可以在 30°至 50°的“安全区”内得到改善。
我们回顾了在 14 个月的时间内由一位外科医生进行的 167 例初次 THA。手术在两个机构进行：一个是住院医院，使用了倾斜计（倾斜计组）；另一个是日间手术中心，由于无法充分消毒，未使用倾斜计（对照组）。我们排除了 47 例体重指数（BMI）>40kg/m、年龄>68 岁或手术指征不是骨关节炎的患者，因为这些患者不能在日间手术中心进行治疗。因此，共有 120 例患者入组，其中倾斜计组 68 例，对照组 52 例。由两名独立的研究人员通过对未标记的平片进行测量来评估髋臼部件的倾斜角度，这两名研究人员并未参与手术。使用多元回归分析来确定使用倾斜计对倾斜角度的影响。
倾斜计组的 THA 平均倾斜角度为 42.9°（95%置信区间（CI）41.7°至 44.0°；范围 29.0°至 63.8°），对照组为 46.5°（95%CI 45.2°至 47.7°；范围 32.8°至 63.2°）（p<0.001）。回归分析确定了由于使用倾斜计导致的 9.1%的倾斜角度差异（p<0.001），并且不使用倾斜计进行的 THA 导致倾斜角度大于 50°的可能性是三倍（优势比（OR）2.8，p=0.036）。两名研究人员测量结果的观察者间可靠性相关系数为 0.95（95%CI 0.93 至 0.97）。
与徒手技术相比，使用简单的倾斜计可显著减少离群值的数量。
Bone Joint J 2018;100-B:862-6.
