Sherman William F, Flick Travis R, Dranoff Charles S, Weintraub Matthew J, Kale Nisha N, Sommi Corinne, Sanchez Fernando L
Department of Orthopaedic Surgery, Tulane University School of Medicine, New Orleans, LA, USA.
Tulane University School of Science and Engineering, New Orleans, LA, USA.
Arthroplast Today. 2021 Jan 11;7:91-97. doi: 10.1016/j.artd.2020.12.002. eCollection 2021 Feb.
Aseptic loosening of the acetabular component remains one of the leading causes of early failure of total hip arthroplasty. Poor apposition of bone onto the implant surface can be due to inaccurate reaming and osteonecrosis of the acetabular bone due to the heat generated while reaming.
New and used acetabular reamers were tested on an MTS system using a clinically relevant force of 87.6 N. A thermal profile and depth achieved by the reamers were analyzed and compared between the 2 cohorts. Heat generated and force required for the community used reamers to achieve the same depth as the new reamers were subsequently analyzed.
The new reamers achieved a depth 3.4 mm deeper than the community reamers ( < .001). The new reamers generated 4.1°C less heat than the community reamers ( = .007) under the same force and time. When programmed to ream to the average depth of the new reamers, the community reamers generated 16.8°C more heat ( = .002) and required forces 95-318% greater than the 87.6 N force used by the new reamers.
Community use of reamers will cause variations in depth of penetration and increased temperatures at a clinically generated force vs new reamers. When community reamers were forced to the same depths the new reamers achieved, a significantly greater amount of heat was generated, and an increased amount of time was needed, both of which are known risk factors for osteonecrosis.
髋臼假体无菌性松动仍然是全髋关节置换早期失败的主要原因之一。骨与植入物表面贴合不佳可能是由于扩孔不准确以及扩孔时产生的热量导致髋臼骨坏死。
在MTS系统上，使用87.6 N的临床相关力对新的和使用过的髋臼扩孔钻进行测试。分析并比较了两组扩孔钻的热分布和达到的深度。随后分析了使用过的扩孔钻达到与新扩孔钻相同深度时产生的热量和所需的力。
新扩孔钻达到的深度比使用过的扩孔钻深3.4 mm（P<0.001）。在相同的力和时间下，新扩孔钻产生的热量比使用过的扩孔钻少4.1°C（P = 0.007）。当设定为扩孔至新扩孔钻的平均深度时，使用过的扩孔钻产生的热量多16.8°C（P = 0.002），并且所需的力比新扩孔钻使用的87.6 N力大95%-318%。
与新扩孔钻相比，临床使用扩孔钻会导致在临床产生的力作用下穿透深度变化和温度升高。当使用过的扩孔钻被迫达到新扩孔钻所达到的相同深度时，会产生明显更多的热量，并且需要更长的时间，这两者都是已知的骨坏死危险因素。
