Periacetabular osteotomy has been described as an effective way of treating symptomatic hip dysplasia. We describe a new minimally invasive technique using a modification of the Smith Peterson approach. 189 consecutive patients operated on between March 2010 and March 2013 were included in the study. Patients who had undergone previous pelvic surgery for DDH were excluded. There were 174 females and 15 males. The mean age was 31 years (15–56) and the mean duration of follow-up was 29 months (14 – 53 months). 90% of cases were Tonnis grade 0 or 1. Twenty-three patients were operated on for primary acetabular retroversion. Functional outcomes were assessed using the NAHS, UCLA and Tegner activity scores. The surgical procedure is performed through an 8–10 cm skin crease incision; a soft tissue sleeve is elevated from the anterior superior iliac spine. The interval medial to the rectus femoris is developed. The hip joint is not opened and fixation of the osteotomy was with three 4.5mm cortical screws. A cell saver was routinely used.Introduction
Patients/Materials & Methods
The cam-type deformity in femoroacetabular impingement
is a 3D deformity. Single measurements using radiographs, CT or
MRI may not provide a true estimate of the magnitude of the deformity.
We performed an analysis of the size and location of measurements
of the alpha angle (α°) using a CT technique which could be applied
to the 3D reconstructions of the hip. Analysis was undertaken in
42 patients (57 hips; 24 men and 18 women; mean age 38 years (16
to 58)) who had symptoms of femoroacetabular impingement related
to a cam-type abnormality. An α° of >
50° was considered a significant
indicator of cam-type impingement. Measurements of the α° were made
at different points around the femoral head/neck junction at intervals
of 30°: starting at the nine o’clock (posterior), ten, eleven and
twelve o’clock (superior), one, two and ending at three o’clock
(anterior) position. The mean maximum increased α° was 64.6° (50.8° to 86°). The two
o’clock position was the most common point to find an increased α°
(53 hips; 93%), followed by one o’clock (48 hips; 84%). The largest α°
for each hip was found most frequently at the two o’clock position
(46%), followed by the one o’clock position (39%). Generally, raised α angles
extend over three segments of the clock face. Single measurements of the α°, whether pre- or post-operative,
should be viewed with caution as they may not be representative
of the true size of the deformity and not define whether adequate
correction has been achieved following surgery. Cite this article:
