Kovalenko et al. review the Tönnis classification of hip osteoarthritis — its historical origins, grade descriptions, and the body of reliability literature — to assess whether the system should guide clinical and surgical decision-making.
When evaluating a young patient for hip preservation surgery (FAI, dysplasia), recognize that the Tönnis classification is least reliable exactly where it matters most — distinguishing Grade 0 from Grade 1.
So a borderline early-arthritis radiograph warrants advanced imaging and caution rather than a confident grade assignment; even Grade 1 disease meaningfully worsens arthroscopy outcomes and THA conversion risk.
Kovalenko et al. review the Tönnis classification of hip osteoarthritis — its historical origins, grade descriptions, and the body of reliability literature — to assess whether the system should guide clinical and surgical decision-making.
When evaluating a young patient for hip preservation surgery (FAI, dysplasia), recognize that the Tönnis classification is least reliable exactly where it matters most — distinguishing Grade 0 from Grade 1.
So a borderline early-arthritis radiograph warrants advanced imaging and caution rather than a confident grade assignment; even Grade 1 disease meaningfully worsens arthroscopy outcomes and THA conversion risk.