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Updated: Aug 11, 2026
In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy
Published on: July 2, 2021
Distinct recovery phenotypes after hip arthroscopy reveal dissociation between daily function and sports performance
Miguel Vázquez1,2,3,4, Roberto Seijas1,2,3, Pedro Alvarez-Díaz1,2,3,4
1Cugat Institue, Hospital Quironsalud Barcelona, Barcelona, Spain.
Background:
Hip arthroscopy outcomes for femoroacetabular impingement remain heterogeneous. The Hip Outcome Score (HOS) comprises 2 distinct subscales measuring activities of daily living and sports performance, yet their dissociation after surgery remains poorly characterised.
Purpose:
To identify distinct recovery phenotypes after hip arthroscopy using unsupervised machine learning and determine preoperative predictors of phenotype membership.
Methods:
We analysed 326 consecutive patients with complete 1-year HOS-ADL and HOS-Sports data. K-means clustering was performed on 5 outcome variables with Gaussian Mixture Model validation. Multinomial logistic regression identified preoperative predictors.
Results:
4 phenotypes emerged: Complete Responders (41.7%), ADL-Dominant Responders (27.3%), Slow Progressors (19.0%), and Non-Responders (12.0%). ADL-Dominant phenotype was predicted by age >40 years (OR 3.42, p < 0.001), Tegner <5 (OR 2.87, p = 0.001), and Outerbridge III-IV (OR 2.41, p = 0.005).
Conclusions:
4 robust recovery phenotypes exist, with 27% demonstrating ADL-sports dissociation predicted by older age, lower activity, and greater chondral damage. Recognition enables personalised preoperative counselling.