Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639# Zhizaoju Road, Shanghai, 200011, People's Republic of China.
J Orthop Surg Res. 2022 Apr 4;17(1):204. doi: 10.1186/s13018-022-03093-6.
Lipped or elevated acetabular liners are to improve posterior stability and are widely used in hip arthroplasty. However, concerns of increasing impingement exist when using such liners and optimal orientation of the elevated rim remains unknown. We aimed to identify the impact of lipped liner on the range of motion (ROM) before impingement and propose its optimal orientation.
An isochoric three-dimensional model of a general hip-replacement prosthesis was generated, and flex-extension, add-abduction and axial rotation were simulated on a computer. The maximum ROM of the hip was measured before the neck impinged on the liner. Different combinations of acetabular anteversion angles ranging from 5 to 30 degrees, and lipped liner orientations from posterior to anterior were tested.
When acetabular anteversion was 10 or 15 degrees, placing the lip of the liner in the posterosuperior of the acetabulum allowed satisfactory ROM in all directions. When acetabular anteversion was 20 degrees, extension and external rotation were restricted. Adjusting the lip to the superior restored satisfactory ROM. When acetabular anteversion was 25 degrees, only placing the lip into the anterosuperior could increase extension and external rotation to maintain satisfactory ROM.
This study showed that optimal lipped liner orientation should depend on acetabular anteversion. When acetabular anteversion was smaller than 20 degrees, placing lip in the posterior allowed an optimally ROM. When acetabular anteversion was greater than 20 degrees, adjusting lip to the anterior allowed a comprehensive larger ROM to avoid early impingement.
带唇或抬高的髋臼衬垫可改善后方稳定性，广泛应用于髋关节置换术。然而，使用此类衬垫时存在增加撞击的担忧，且抬高边缘的最佳方位尚不清楚。我们旨在确定带唇衬垫对撞击前活动范围（ROM）的影响，并提出其最佳方位。
生成通用髋关节置换假体的等容三维模型，并在计算机上模拟屈伸、内收外展和轴向旋转。测量颈撞击衬垫前髋关节的最大 ROM。测试了髋臼前倾角为 5 度至 30 度范围内不同组合的髋臼前倾角，以及从后向前的带唇衬垫方位。
当髋臼前倾角为 10 度或 15 度时，将衬垫的唇置于髋臼的后上方可在各个方向提供满意的 ROM。当髋臼前倾角为 20 度时，伸展和外旋受限。调整唇至上方可恢复满意的 ROM。当髋臼前倾角为 25 度时，只有将唇置于前上方才能增加伸展和外旋以维持满意的 ROM。
本研究表明，最佳带唇衬垫方位应取决于髋臼前倾角。当髋臼前倾角小于 20 度时，将唇置于后方可获得最佳 ROM。当髋臼前倾角大于 20 度时，调整唇至前方可获得全面更大的 ROM，以避免早期撞击。
