[Surgical management of posterior cruciate ligament avulsion fracture]

Injury to the posterior cruciate ligament (PCL) is relatively rare and, if combined with avulsion fracture of the PCL insertion site, it accounts for only a small number of knee injuries. This is why PCL avulsion fracture is an easily missed diagnosis resulting in knee instability and arthritis development. The aim of this study was to show the necessity of surgical treatment of these injuries.

Between January 2004 and September 2005, four patients with PCL injury underwent surgery. Three had avulsion fracture at the PCL insertion site, and in one the avulsion fracture involved also the intercondylar eminence. The average follow- up was 15 months, with a range of 5 to 20 months.

The diagnosis was based on clinical examination, plain X-ray and MRI results. After arthroscopic treatment of the anterior compartment, the posterior compartment was treated from the posteromedial and the posterolateral approach. Using a K-wire for guidance, a tunnel was drilled and the fragment was fixed with an absorbable cannulated screw. Postoperatively, the limb was immobilized in a rigid brace at a 20 degrees flexion for 4 weeks followed by passive exercise rehabilitation. Within 10 weeks of surgery full weight-bearing was possible in all patients. Outcome evaluation was based on clinical, radiographic and MRI examination shortly after surgery and at 3-month follow-up.

None of the four treated knee joints had any post-operative instability. The PCL was in a correct position and showed appropriate tension on MRI scans.

Today arthroscopically-assisted operations are preferred to conservative treatment or open osteosynthesis. An exact diagnosis is best made on the basis MRI examination. To fix the bony fragment, various techniques can be used, such as hooked nail, screw, K-wire or traction suture through the proximal tibia. The method used usually depends on the size of a bony fragment.

The advantages of arthroscopic surgery include faster healing and rehabilitation and less pain and trauma associated with the operative procedure. A readily performed arthroscopic procedure prevents knee joint instability and arthritis development. The outcomes achieved in our patients give support to the indication for surgical treatment in this kind of knee injury.