Surgical hip dislocation and varus derotation osteotomy for extra-articular cause of femoroacetabular impingement: a single case report

Figures

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  Fig. 1.. The CCD angle was 145°, the LCEA was 42° and asphericity was present on X-ray image.

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  Fig. 2.. The 3D CT view of femur head–neck area after arthroscopic surgery.

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  Fig. 3.. The patient continued to walk with toes out and thigh abducted despite arthroscopic surgery.

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  Fig. 4.. (A) The orthogonal 3D CT view of femur neck and trochanter showed the external torsional deformity. (B) Right femur neck axis. (C) Right distal femur trans-epicondylar axis. (D) The right distal femoral transepicondylar axis was externally rotated by 10° compared with the right femur neck axis, which meant femoral retroversion.

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  Fig. 5.. (A) Two parallel K-wires inserted above and below the osteotomy site were used to measure varization and derotation after osteotomy. (B) The paths of two neck screws were guided by preemptive insertion of K-wires in lateral as well as anteroposterior fluoroscopic film.

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  Fig. 6.. (A) The extra-articular impingement was confirmed by viewing the contact between the inferior intertrochanteric line area and the iliopectineal area with internal rotation in both 90 and 20° flex. (B) The previous femoroplasty area was identified by surgical hip dislocation.

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  Fig. 7.. (A) Acetabular chondral lesion at the chondrolabral junction of 12 o'clock position. (B) A small rim defect and labral rent at the chondrolabral junction of 2 o’clock position.

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  Fig. 8.. (A) Acetabular labral takedown, rim resection and labral refixation with two anchors. (B) In vivo lateral opening and derotation by divergence and rotation of the K-wires and subsequent fixation of neck and plate screw. (C) After the final fixation of the calcar neck and the other plate screws, the osteotomized digastric greater trochanter was relocated and fixed with three large screws.

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  Fig. 9.. The CCD angle was changed to 131° and the LCEA decreased to 28°.

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  Fig. 10.. The post-operative right femur neck anteversion was 2.6°.

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  Fig. 11.. Solid bony union on 2-year post-operative X-ray films.