Adolescent and Young Adult Hip Dysplasia



Adolescent and Young Adult Hip Dysplasia


Young-Jo Kim



I. Periacetabular Osteotomy



  • Abductor-sparing surgical approach


  • Rectus-sparing anterior approach


  • Ischial osteotomy


  • Superior ramus osteotomy


  • Iliac osteotomy and posterior column split


  • Acetabular fragment reduction


  • Intraoperative range of motion assessment


  • Anterior arthrotomy and femoral osteoplasty


Operative Indications



  • Significant symptoms affecting daily life


  • Classic acetabular dysplasia deformity



    • Lateral center-edge angle of Wiberg less than 20°


    • Tönnis angle greater than 10°


    • Anterior center-edge angle less than 20°


  • Relative indications



    • Microinstability due to ligamentous laxity, capsular deficiency, and excessive femoral anteversion


    • Pincer impingement due to global acetabular overcoverage or acetabular retroversion



Examination Under Anesthesia



  • Maximal hip flexion of the affected hip


  • Hip internal rotation in 90° of flexion of the affected hip


  • Flexion and internal rotation will decrease when anterior and lateral coverage is increased in classic acetabular dysplasia correction


  • Need range of motion prior to surgery to determine the extent of decrease













Positioning



  • Patient is positioned supine with the affected hip draped free


  • Decrease the lumbar lordosis as much as possible. If needed, place a blanket roll under the contralateral limb if a flexion contracture exists in order to minimize pelvic tilt (Figure 21.1)


Surgical Approach



  • Bikini skin incision is marked: start 1 cm below iliac crest to 1 to 2 cm past the anterior line over the hip joint (Figure 21.2)


  • Skin is incised and dissection carried down sharply through the Scarpa fascia


  • External oblique fascial is incised laterally, and the muscle is cleared off the iliac crest periosteum (Figure 21.3)


  • Tensor fascial is incised from the anterior superior iliac spine (ASIS) going distal and lateral at approximately 30° angle (Figure 21.4)


  • Dissection is carried down to the rectus tendon through the tensor fascia envelope (Figure 21.5)


  • The iliacus muscle is elevated off the ilium subperiosteally


  • The superior iliac spine is osteotomized using an osteotome (Figure 21.6)























  • The interval just medial to the direct head of the rectus is opened, and the iliocapsularis is detached off the inferior iliac spine down to the capsule (Figure 21.7). This is not an internervous plane, so do not carry the dissection distal to the lateral femoral circumflex vessels


  • The psoas tendon sheath is identified from inside the pelvis and following this down to the capsule by gently dividing the iliocapsularis muscle (Figure 21.8)


  • Develop the interval between the psoas tendon and the capsule using meniscus scissors and pass the scissors down to the ischium (Figure 21.9)


Techniques in Steps


Ischial Osteotomy



  • Pass a Lane retractor through the psoas capsule interval and feel the ischium


  • Bring the fluoroscope into the anteroposterior (AP) position and may check to verify the Lane retractor is in the infracotyloid groove


  • You may slide the narrow Ganz osteotome down to the ischium by lifting the Lane retractor anteriorly and place the osteotome underneath


  • Verify the position of the Ganz osteotome using fluoroscope in the AP position (Figure 21.10)