- Discussion:
- optimal age for the medial approach:
- is of more value in the child younger than 18 months but older than 7 months;
- when this procedure is used in infants younger than 7 months, there may be a higher risk of AVN, but some authors feel that the risk of AVN is increased in children older than 10 months of age;
- anatomical considerations:
- medial approach may occur either anteromedial or posteromedial depending whether surgeon goes anterior or posterior to adductor brevis;
- procedure may involve division of the psoas tendon, since it can be an extra-articular barrier to reduction;
- advantages:
- minimum dissection & blood loss;
- allows direct approach to common obstacles to reduction (such as the psoas tendon);
- psoas tendon, capsular constriction, & transverse acetabular ligament;
- disadvantages:
- poor access to acetabulum (neolimbus, ligamentum teres, & pulvinar);
- does not allow capsulorraphy (which is required in older patients);
- AVN: risk of AVN is about 15%;
- need for additional surgical procedures: 10-20%;
- contra-indications:
- medial approach is usually not used once child who has begun to walk;
- medial approach not used when femoral head has migrated proximally;
- Antermedial Approach:
- may be indicated for children w/ DDH who are less than 24 months old;
- may be contraindicated for older children and for children w/ high hip dislocation;
- address obstacles to reduction;
- avoids damage to the abductors and damage to the iliac apophysis;
- has low incidence of recurrent dislocations & AVN (however, some point out that there is damage to the medial circumflex vessels w/ this approach);
- incision:
- incision proceeds anterior to adductor brevis & either anterior or posterior to pectineus, to expose iliopsoas & hip capsule;
- branch of MFCA must be ligated during anteromedial approach;
- reference:
- Anteromedial approach to reduction for congenital hip dysplasia. Weinstein SL. Orthop. Surg. 1987(6):2.
- Ludloff Approach:
- dissection is between adductor longus & brevis muscles anteriorly, and gracilis & adductor magnus muscles posteriorly;
- deeper dissection is between adductor brevis & adductor magnus;
- make longitudinal incision on medial aspect of thigh, beginning about 2.5 cm distal to pubic tubercle & over interval between gracilis & adductor longus muscles;
- this should reveal the adductor brevis w/ overlying anterior branch of obturator nerve & this is retracted to observe posterior branch overlying the adductor magnus;
- develop plane between adductor longus & brevis muscles anteriorly and gracilis & adductor magnus muscles posteriorly;
- expose posterior branch of obturator nerve & neurovascular bundle of the gracilis;
- lesser trochanter & capsule of hip joint are located in floor of wound;
- reference:
- Open Reduction through a Medial Approach for Congenital Dislocation of the Hip. A Critical Review of the Ludloff Approach in Sixty-six Hips.
- Posteromedial Approach: (Ferguson Approach)
- low incidence of AVN and recurrent dislocation;
- place pt in supine position w/ affected hip abducted & flexed 90 deg;
- make straight incision along the posterior margin of the adductor longus beginning at its origin and extending distally;
- incise the deep fascia in line with the skin incision and by blunt dissection with the finger separate the adductor longus anteriorly from the adductor magnus and gracilis posteriorly;
- course between adductor brevis and adductor magnus directly to hip capsule;
- identify the psoas tendon, and divide it transversely;
- reference:
- Open reduction for congenital dislocation of the hip using the Ferguson procedure. A review of twenty-six cases.
Congenital dislocation of the hip