Miettinen Simo S A, Mäkinen Tatu J, Laaksonen Inari, Mäkelä Keijo, Huhtala Heini, Kettunen Jukka, Remes Ville
Department of Orthopaedics, Traumatology and Hand Surgery, Kuopio University Hospital, Kuopio, Finland.
Department of Orthopaedics and Traumatology, Helsinki University Hospital and University of Helsinki, Sairaalakatu 1, 01400, Vantaa, Finland.
Int Orthop. 2017 Apr;41(4):715-722. doi: 10.1007/s00264-016-3254-8. Epub 2016 Aug 10.
Early aseptic loosening of cementless monoblock acetabular components is a rare complication of total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA). The purpose of this study was to evaluate the incidence and risk factors for early aseptic loosening of the cementless monoblock acetabular components.
This retrospective analysis consisted of 4,043 cementless hip devices (3,209 THAs and 834 HRAs). We identified 41 patients with early aseptic loosening of the acetabular component. A control group of 123 patients without acetabular component loosening was randomly selected. The demographic data and risk factors for loosening of the acetabular component were evaluated. The mean follow-up time was 4.6 years (range, 1.7-7.8). The end-point was acetabular revision.
The incidence of early acetabular component loosening was 1.0 %. Mean time to revision was 1.2 years (SD 1.6, range 0.0-5.4). There was significantly more Dorr type A and C acetabular morphology in patients with early loosening (P = 0.014). The loosened components were implanted to more vertical (P < 0.001) and less anteverted (P = 0.001) position than those of the control group. Presence of acetabular dysplasia or acetabular component type did not associate to early loosening.
Acetabular morphology (Dorr type A and C) and component positioning vertically and less anteverted were more common in patients with early aseptic loosening of cementless acetabular components. Suboptimal cup position most likely reflects challenges to obtain sufficient stability during surgery. We hypothesize that errors in surgical technique are the main reason for early loosening of monoblock acetabular components.
非骨水泥型整体髋臼组件的早期无菌性松动是全髋关节置换术（THA）和髋关节表面置换术（HRA）的一种罕见并发症。本研究的目的是评估非骨水泥型整体髋臼组件早期无菌性松动的发生率及危险因素。
本回顾性分析纳入了4043例非骨水泥型髋关节假体（3209例THA和834例HRA）。我们确定了41例髋臼组件早期无菌性松动的患者。随机选取123例无髋臼组件松动的患者作为对照组。评估髋臼组件松动的人口统计学数据和危险因素。平均随访时间为4.6年（范围1.7 - 7.8年）。终点为髋臼翻修术。
髋臼组件早期松动的发生率为1.0%。翻修的平均时间为1.2年（标准差1.6，范围0.0 - 5.4年）。早期松动患者中Dorr A型和C型髋臼形态明显更多（P = 0.014）。与对照组相比，松动组件植入的位置更垂直（P < 0.001）且前倾角更小（P = 0.001）。髋臼发育不良或髋臼组件类型与早期松动无关。
髋臼形态（Dorr A型和C型）以及组件垂直且前倾角较小的位置在非骨水泥髋臼组件早期无菌性松动患者中更为常见。髋臼杯位置欠佳很可能反映了手术过程中获得足够稳定性的挑战。我们推测手术技术失误是整体髋臼组件早期松动的主要原因。
