A new article published in Zeitschrift fur Orthopadie und Unfallchirurgie discussed that total hip arthroplasty in patients with high hip dislocation is a surgically demanding procedure. This is due to the congenital disorder of hip maturation and the resulting anatomical features.

The authors stated that the aim of arthroplasty is implantation of the cup prosthesis in the original center of rotation, at the same time, correcting femoral deformities and reducing the hip joint.The indications include advanced osteoarthritis in the secondary acetabulum, existing instability, severe contractures and secondary changes in adjacent joints. Meanwhile, the contraindications are cerebrospinal dysfunction with impaired coordination, muscular dystrophies, overt metabolic bone disorders and complete or nearly complete absence of muscles that stabilize the hip or the hip-stabilizing musculature.

This article elaborated on the operation technique, which is usually performed through an anterolateral approach with the patient supine, or through a posterolateral approach with the patient on his side. Sparing the pelvitro-chanteric muscles is crucial for the functional outcome, while exposure of the original acetabulum is essential for correct and secure placement of the cup component. A planned shortening femoral osteotomy is performed above an increase in length of more than 3.0 cmin patients without previous surgery, and depending on the operative findings in previously operated patients. The bone fragment to be removed,must be at approximately 60% of the distance between the planned and the preoperative position of the trochanter tip. Additional fixation is necessary only in the absence of primary stability between the parts of the femur divided by osteotomy.

The postoperative management should be individualized depending on the stability of the prosthetic cup fixation, bone quality, rotational stability of the stem in both segments of the femur after osteotomy, existing soft tissue contractures and the resulting postoperative leg length difference.The most frequent complications are nerve injuries; femoral fractures;malpositioning ofcomponents; absence of integration of components – usually due to inadequate primary stability; joint instability due to damage to the pelvitro-chanteric muscles, and therefore, an increased risk of dislocation;pseudarthrosis of the femoral osteotomy; and increased perioperative blood loss due to the prolonged operation time.

In summary, it was stated that recent results reveal that subtrochanteric shortening osteotomy in patients with high hip dislocation, with anatomic reconstruction of the original center of rotation, delivers good functional results with insignificantly increased 10-year loosening rates compared tothe standard management of primary hip osteoarthritis.

Source: Zeitschrift fur Orthopadie und Unfallchirurgie. 2020 Mar 4. doi: 10.1055/a-0946-2750.