Valera Màrius, Ibáñez Natalia, Sancho Rogelio, Llauger Jaume, Gich Ignasi
Hip Unit, Department of Orthopaedics Surgery, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain.
Department of Orthopaedics Surgery, Hospital Residència Sant Camil - Seu, Consorci Sanitari del Garraf, Sant Pere de Ribes, Spain.
Arch Orthop Trauma Surg. 2018 Jan;138(1):73-82. doi: 10.1007/s00402-017-2811-y. Epub 2017 Oct 30.
Acetabular overcoverage promotes hip osteoarthritis causing a pincer-type femoroacetabular impingement. Acetabular coverage in the horizontal plane is usually poorly defined in imaging studies and may be misdiagnosed. The goal of this study was to analyze the role of acetabular overcoverage measured in the frontal plane and in the horizontal plane by CT scan and to determine its relationship with other anatomic features in the onset of hip arthritis in young adults.
We compared prospectively CT scans from two groups of adults of 55 years or younger: the patient group (n = 30) consisted of subjects with diagnosis of early hip arthritis (Tönnis Grade I or II) and the control group (n = 31) consisted of subjects with healthy hips. Two independent observers analyzed centre edge angle (CEA), acetabular anteversion angle (AAA), anterior sector acetabular angle (AASA), posterior sector acetabular angle (PASA), horizontal acetabular sector angle (HASA), femoral anteversion angle (FAVA), alpha angle (AA), and Mckibbin Instability Index (MI).
Angles measuring the acetabular coverage on the horizontal plane (AASA, PASA and, HASA) were significantly higher in the patient group (p < 0.001, p = 0.03 and p < 0.001, respectively). Pearson's correlation coefficient showed a positive correlation between CEA and HASA in patients (r = 0.628) and in controls (r = 0.660). However, a high CEA (> 35º) was strongly associated with a high HASA (> 160º) in patients (p = 0.024) but not in controls (p = 0.21), suggesting that pincer should be simultaneously present in the horizontal and frontal plane to trigger hip degeneration. No significant association was detected between a high alpha angle (> 60º) and a high CEA (> 35º suggesting that a mixed pincer-cam aetiology was not prevalent in our series. Multivariate regression analysis showed the most significant predictors of degenerative joint disease were HASA (p = 0.008), AA (p = 0.048) and ASAA (p = 0.004).
Acetabular overcoverage in the horizontal plane plays an important role in the onset of early hip arthritis. Considering that this condition is usually underdiagnosed, we suggest the anterior sector acetabular angle, the posterior sector acetabular angle, and the horizontal acetabular sector angles be routinely included in decision-making algorithms in hip conservative surgery to better define hips-at-risk of developing early hip osteoarthritis.
髋臼过度覆盖会引发髋关节骨关节炎，导致钳夹型股骨髋臼撞击症。在影像学研究中，髋臼在水平面的覆盖情况通常界定不清，可能会被误诊。本研究的目的是分析通过CT扫描测量的髋臼在额状面和水平面的过度覆盖情况的作用，并确定其与年轻成年人髋关节关节炎发病时其他解剖特征的关系。
我们前瞻性地比较了两组55岁及以下成年人的CT扫描结果：患者组（n = 30）由诊断为早期髋关节关节炎（Tönnis I级或II级）的受试者组成，对照组（n = 31）由髋关节健康的受试者组成。两名独立观察者分析了中心边缘角（CEA）、髋臼前倾角（AAA）、髋臼前扇区角（AASA）、髋臼后扇区角（PASA）、髋臼水平扇区角（HASA）、股骨前倾角（FAVA）、α角（AA）和麦基宾不稳定指数（MI）。
患者组中测量髋臼在水平面覆盖情况的角度（AASA、PASA和HASA）显著更高（分别为p < 0.001、p = 0.03和p < 0.001）。Pearson相关系数显示，患者组（r = 0.628）和对照组（r = 0.660）中CEA与HASA之间呈正相关。然而，患者组中高CEA（> 35°）与高HASA（> 160°）密切相关（p = 0.024），而对照组中则不然（p = 0.21），这表明钳夹型撞击在水平面和额状面应同时存在才能引发髋关节退变。未检测到高α角（> 60°）与高CEA（> 35°）之间存在显著关联，这表明混合钳夹-凸轮病因在我们的系列研究中并不普遍。多变量回归分析显示，退行性关节病最显著的预测因素是HASA（p = 0.008）、AA（p = 0.048）和ASAA（p = 0.004）。
髋臼在水平面的过度覆盖在早期髋关节关节炎的发病中起重要作用。鉴于这种情况通常诊断不足，我们建议在髋关节保守手术的决策算法中常规纳入髋臼前扇区角、髋臼后扇区角和髋臼水平扇区角，以更好地界定有早期髋关节骨关节炎发病风险的髋关节。
