PurposeThe purpose of this study was to study dynamic hip external rotation strength in patients with Femoroacetabular impingement surgery (FAI) syndrome who have undergone unilateral arthroscopic treatment and returned to sports.

MethodsA cross-sectional study was performed using an observational group (n = 22) and a matched control group (n = 22). Dynamic external rotation strength of the hip was measured using the Augustsson Strength Test, which has shown high reliability for examining side-to-side differences in hip muscle strength.

ResultsDynamic hip external rotation strength was significantly lower in the arthroscopically treated hip compared with the non-treated hip within the observational group (p < 0.004).

ConclusionThis cross-sectional study shows that at return to sports, patients who have undergone unilateral arthroscopic treatment for FAI syndrome do not have adequate hip muscle strength recovery. Rehabilitation protocols should, therefore, emphasise post-operative strength training of the hip muscles. Additional research is needed to determine the consequences of reduced hip strength for the long-term outcome after arthroscopically treated FAI. Clinical relevance: The results of this study underline the importance of post-operative strength training prior to returning to sports in patients with femoroacetabular impingement surgery.

Level of evidenceIII.