Open reduction, resorbable pin fixation

Large osteochondral fragments can be reattached with resorbable pins.

For good fixation, the pins must be inserted in a divergent manner so that the fragment cannot move.

This procedure is normally performed with the patient in a lateral position.

See also the additional material on preoperative preparation.

The preferred approach is via a surgical hip dislocation. This approach offers optimal assessment, reduction, and fixation.

Once the femoral head is dislocated, the fragment is reduced anatomically.

If there is a delay to surgery, swelling of the cartilage of the fragment may be seen. This may need to be trimmed in order to reduce it fully.

The fragment is held in place with finger pressure and one or two 1.2 or 1.6 mm K-wire(s) are temporarily inserted to hold the reduction.

When the fragment is perfectly reduced, two, three, or four divergent drill holes (according to the size of the fragment) are made for the resorbable pins.

Completely intraepiphyseal placement is preferred.

The pins are inserted and cut at the level of the joint surface.

The K-wires are then carefully removed so as to avoid disturbing the pins.

Alternatively, pins with heads are impacted so that the heads are just beneath the surface of the cartilage.

Once the fixation is completed, the hip is reduced and free movement of the head without moving the fragment is checked.

Only controlled range of motion, without forced movements, is permitted for 4-6 weeks postoperatively.

Full weight bearing is permitted after wound healing.

After surgical stabilization, the construct should be sufficiently robust to allow protected weight bearing. Smaller children may not be able to comply with this and may need immobilization.

See the additional material on postoperative infection.

Forces through the hip are less with toe-touch weight bearing than with no weight bearing. Therefore, toe-touch is normally recommended for initial mobilization. This needs to be taught to children by a physiotherapist.

Range-of-movement exercises should start in the immediate postoperative period to prevent stiffness. Surgeons should indicate if any extremes of movement are forbidden.

Having started with toe-touch weight bearing, children progress to partial weight bearing and then to full weight bearing according to their age and the predicted rate of healing of their fracture.
Even older adolescents should be fully weight bearing without aids at three months.

Swimming can be allowed as soon as partial weight bearing is permitted.
Contact sports should be avoided for at least six months.

X-rays are generally taken immediately after the surgery and at 6 and 12 weeks.

Implants that cross the physis should be removed if there is significant growth remaining. The fracture should be healed and consolidated prior to removal (see Healing times).

Implants in young children should always be removed to prevent them from being covered by bony overgrowth.

Implant removal is not compulsory in adolescents.