[Refixation of osteochondral flake fractures after patellar dislocation-The parachute technique]

Patellar dislocations are a common occurrence in orthopedic practice, often accompanied by osteochondral fractures of the retropatellar cartilage surface, known as flake fractures, in up to 58% of cases. The parachute technique represents a simple and cost-effective surgical option aimed at restoring osteochondral integration and preserving native cartilage.

Flake fracture of the patella with osteochondral fragments.

Patella fracture.

By utilizing transpatellar, absorbable sutures, a stable osteochondral interface is achieved without penetrating the fragment itself.

Postoperative treatment involves partial weight-bearing with a maximum of 20 kg for 6 weeks in full knee extension. In addition, the range of motion of knee flexion is limited to 30° and is increased by 30° every 2 weeks.

To examine the short- to medium-term clinical outcomes, all patients with acute patellar dislocation treated using the parachute technique between 01/2012 and 11/2022 were included. Clinical outcomes were assessed using the visual analog scale (VAS), Tegner Activity Scale (TAS), Kujala Score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC). Out of 20 patients, 19 (10 men, 11 right-sided, 95% follow-up rate) could be recruited for postoperative evaluation. The average follow-up period was 62.5 ± 20.5 months. The clinical outcome scores yielded the following results: VAS 0.5 ± 1.6, TAS 5.8 ± 2.2, Kujala 89.4 ± 12.5, KOOS 87.8 ± 14.1, and IKDC 86.7 ± 14.3. Overall, 18 patients (90.0%) expressed willingness to undergo the procedure again. At the time of follow-up, 19 patients (95.0%) were satisfied with the surgical outcome. One patient (23-year-old man) required revision. None of the included patients suffered from the recurrence of patellar dislocation. In summary, the parachute technique demonstrated excellent clinical function in the short- to medium-term follow-up for acute patellar dislocation.