Miki Hidenobu, Sugano Nobuhiko, Yonenobu Kazuo, Tsuda Kosuke, Hattori Maki, Suzuki Naoki
Department of Orthopedic Surgery, Osaka National Hospital, Osaka, Japan.
Clin Biomech (Bristol). 2013 Feb;28(2):182-6. doi: 10.1016/j.clinbiomech.2012.11.009. Epub 2012 Dec 4.
Dislocation is a major complication after total hip arthroplasty. Prosthesis impingement is considered to be an important cause of dislocation because impingement marks are more frequently found on retrieved cups or liners in patients who have undergone revision surgery because of dislocation (80%-94%) than in those who have undergone reoperation for other reasons (51%-56%). However, it remains a question whether impingement marks are the cause of dislocation or are instead its result. To clarify the issue, it is necessary to confirm noninvasively whether the point of impingement matches the patient's hip position when dislocation occurs.
Using four-dimensional patient-specific analysis, we recorded prosthesis impingement in 10 hips with instability after primary total hip arthroplasty when the patients reproduced the dislocation-causing motion.
We found prosthesis impingement to be related to at least instability in 6 of 10 hips with dislocation after primary total hip arthroplasty and in 4 of 4 hips that underwent revision surgery for recurrent dislocation. All impingements occurred between the anterior wall of the liner and the stem neck in posterior dislocation and between the posterior wall of the liner and the stem neck in anterior dislocation. Revision surgery in 1 of those 4 hips revealed 2 impingement marks on the retrieved liner that closely matched the prosthesis impingement point and the dislocation pathway of the metal head on the liner that were detected earlier during motion analysis.
Prosthesis impingement is an important factor in dislocation after total hip arthroplasty.
脱位是全髋关节置换术后的主要并发症。假体撞击被认为是脱位的一个重要原因，因为在因脱位而接受翻修手术的患者（80%-94%）的取出髋臼杯或内衬上发现撞击痕迹的频率高于因其他原因接受再次手术的患者（51%-56%）。然而，撞击痕迹是脱位的原因还是其结果仍是一个问题。为了阐明这个问题，有必要在脱位发生时通过无创方法确认撞击点是否与患者的髋关节位置相匹配。
我们采用四维个体化分析，记录了10例初次全髋关节置换术后出现不稳定的患者在重现致脱位动作时的假体撞击情况。
我们发现，在10例初次全髋关节置换术后脱位的患者中，有6例以及在4例因复发性脱位接受翻修手术的患者中，至少有4例假体撞击与不稳定有关。所有撞击均发生在后脱位时内衬前壁与柄颈之间，以及前脱位时内衬后壁与柄颈之间。在这4例患者中的1例进行翻修手术时，在取出的内衬上发现了2处撞击痕迹，这些痕迹与假体撞击点以及在运动分析早期检测到的金属头在内衬上的脱位路径紧密匹配。
假体撞击是全髋关节置换术后脱位的一个重要因素。
