A painful squat test provides limited diagnostic utility in CAM-type femoroacetabular impingement.
OBJECTIVE
The purpose of this study is to determine the relationship between a symptomatic maximal squat and the presence of radiographic CAM-type femoroacetabular impingement (FAI) on magnetic resonance imaging (MRI) and to determine the sensitivity and specificity of a maximal squat test for the presence of radiographic CAM-type femoral deformity in an adult population.


METHODS
In this pilot study, 76 consecutive patients were recruited from an outpatient clinic at McMaster University. All patients presented with pre-arthritic hip pain and were asked to perform a maximal squat. The results of this test were compared to magnetic resonance imaging and magnetic resonance angiographic (MRI and MRA) findings evaluating and characterizing CAM-type FAI deformity.


RESULTS
The sensitivity and specificity of the maximal squat test were 75 % (56.6-88.5 %) and 41 % (27.0-56.8 %), respectively, for CAM-type FAI deformity. The positive and negative likelihood ratios were modest at 1.3 (0.9-1.7) and 0.6 (0.3-1.2), respectively. This means that a 30 % pre-test probability is improved to 36 % following a positive squat test and reduced to 20 % with a negative squat test.


CONCLUSIONS
The maximal squat test was found to have marginal incremental diagnostic ability for CAM-type FAI. Its utility in the diagnostic evaluation of FAI remains limited. This survey elucidates areas of research for future studies relevant to the clinical diagnosis of FAI.
Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, ON, Canada, trauma7@mcmaster.ca.
Olufemi
O
Ayeni
Raymond
R
Chu
Bandar
B
Hetaimish
Liin
L
Nur
Nicole
N
Simunovic
Forough
F
Farrokhyar
Asheesh
A
Bedi
Mohit
M
Bhandari
D000328:Adult; D018771:Arthralgia; D005260:Female; D057925:Femoracetabular Impingement / Q000175:diagnosis*; D006621:Hip Joint; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010808:Physical Examination; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity