MRI morphometry, cartilage damage and impaired function in the follow-up after slipped capital femoral epiphysis.
OBJECTIVE
To assess rotation deficits, asphericity of the femoral head and localisation of cartilage damage in the follow-up after slipped capital femoral epiphysis (SCFE).


METHODS
Magnetic resonance imaging studies were obtained in adult patients with a history of SCFE. A total of 35 hips after SCFE in 26 patients (mean age 24.1 +/- 6.5, mean follow-up 11.9 +/- 6.1 years) were evaluated. The control group comprised 20 healthy hips from 10 young adults with an average age of 23.9 +/- 3.7 years. The MR protocol included a T1-weighted sequence with a 3D volumetric interpolated breath-hold sequence and a radial 2D proton density-weighted sequence around the femoral neck. Images were evaluated for alpha angle and cartilage damage in five positions around the femoral head. Hip function was evaluated at the time of MRI and correlated with MRI results. Mann-Whitney U test and Spearman's correlation coefficient were used for statistical analysis.


RESULTS
In the hips after SCFE alpha angles were significantly increased in the anterosuperior (74.1 degrees +/- 18.8 degrees ) and superior (72.5 degrees +/- 21.5 degrees ) positions and decreased in the posterior position (25.0 degrees +/- 7.2 degrees ). Cartilage damage was dominant in the anterosuperior and superior positions. Impaired rotation significantly correlated with increased anterosuperior, superior and posterosuperior alpha angles.


CONCLUSIONS
The data support an anterosuperior and superior cam-type deformity of the femoral head-neck junction in the follow-up after SCFE. MRI after SCFE can be used to assess anterosuperior and superior alpha angles, since the anterior alpha angle by itself may underestimate asphericity and is not associated with rotation deficits.
Miese
Falk R
FR
Institute of Radiology, MNR Clinic, University Hospital Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany. Falk.Miese@med.uni-duesseldorf.de
Zilkens
Christoph
C
Holstein
Arne
A
Bittersohl
Bernd
B
Kröpil
Patric
P
Jäger
Marcus
M
Mamisch
Tallal C
TC
Krauspe
Rüdiger
R
Mödder
Ulrich
U
Fürst
Günther
G
D002357:Cartilage Diseases / Q000209:etiology* / Q000473:pathology*; D002358:Cartilage, Articular / Q000293:injuries / Q000473:pathology*; D004839:Epiphyses, Slipped / Q000150:complications* / Q000473:pathology*; D005260:Female; D005269:Femur / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055815:Young Adult