McBride Andrew, Flynn Jennifer, Miller George, Barnes Matthew, Mackie Scott
Department of Orthopaedics, Royal Hobart Hospital, Hobart, Tasmania, Australia.
ANZ J Surg. 2013 Mar;83(3):171-4. doi: 10.1111/j.1445-2197.2012.06176.x. Epub 2012 Aug 21.
Correct acetabular component positioning during total hip arthroplasty affects the restoration of normal biomechanics, component wear and failure rates. This study examined whether a patient's body mass index (BMI) affects the accuracy of acetabular component placement in terms of the post-operative abduction angle.
This was a retrospective review of 102 total hip arthroplasties performed from May 2009 in a single institution. The acetabular abduction angle was measured on the post-operative radiographs of the included patients. Statistical analysis of variance and t-tests were performed using Microsoft Excel to compare the mean abduction angles of patients grouped according to their BMI.
Comparison of the mean abduction angle between those with BMI < 25 and BMI > 25 showed a statistically significant difference (P = 0.003). Analysis of variance between all BMI groups was statistically significant (P = 0.01). Patients in the lowest centile of abduction angle had an average BMI of 28. Patients in the highest centile of abduction angle had an average BMI of 33.
This study shows that patients with a normal BMI tend to have smaller abduction angles. Overweight or obese patients, on average, have a normal abduction angle but are more likely to have an 'open cup'. A number of factors unique to obese and overweight patient may contribute to an 'open cup' and less accurate cup placement.
全髋关节置换术中髋臼假体的正确定位会影响正常生物力学的恢复、假体磨损及失败率。本研究探讨患者的体重指数(BMI)是否会在术后外展角度方面影响髋臼假体置入的准确性。
这是一项对2009年5月起在单一机构进行的102例全髋关节置换术的回顾性研究。在纳入患者的术后X线片上测量髋臼外展角度。使用Microsoft Excel进行方差分析和t检验,以比较根据BMI分组的患者的平均外展角度。
BMI<25和BMI>25患者的平均外展角度比较显示出统计学上的显著差异(P = 0.003)。所有BMI组之间的方差分析具有统计学意义(P = 0.01)。外展角度最低百分位数的患者平均BMI为28。外展角度最高百分位数的患者平均BMI为33。
本研究表明,BMI正常的患者往往外展角度较小。超重或肥胖患者平均有正常的外展角度,但更有可能出现“髋臼杯开口”。肥胖和超重患者特有的一些因素可能导致“髋臼杯开口”和髋臼杯置入准确性降低。