2020 Volume 39 Issue 2 Pages 83-87
Introduction: Habitual patella dislocation can occur in young patients with open growth plate and requires surgery. We treated a patient with this condition with vastus medialis advancement, lateral retinaculum release, and Roux-Goldthwait procedure.
Case Presentation: The patient was an 11-year-old girl who had initial patella dislocation during a hurdle race at 7 years old. She became aware of knee pain and anxiety that interfered with daily life. At the first examination, valgus knee was note and the patella was dislocated laterally in knee flexion ≥30°. Apprehension test was positive and Kujara score was 65. Plain radiography showed a valgus knee, lateral deviation of the patella, and a Q angle of 21°. In the lateral view, the patella appeared thick, but patella alta was absent. In the axial view, the sulcus angle was 173°and the patella was dislocated laterally at flexion ≥30°. Based on these findings, the patient was diagnosed with habitual patella dislocation and surgical treatment was selected. Normal surgical procedures, such as medial patellofemoral ligament (MPFL) reconstruction and anterior transfer of tibial tuberosity, may influence the epiphyseal growth plate because growth plate was open. Thus, stabilization was applied using lateral retinaculum release, vastus medialis advancement, and Roux-Goldthwait procedure. In after-treatment, plaster fixation was performed for 2 weeks and ROM training up to 90°was initiated at 2 weeks. ROM with no limitation was permitted at 6 weeks. At one year after surgery, ROM is 0-153°, there is no patella dislocation or anxiety, negative apprehension test, and the course is favorable with no interference with activities of daily living.
Discussion: Habitual patella dislocation often has an anatomical predisposition and develops with open growth plate. Early reduction of the patella resulted in favorable fitting of the pulley surface in pulley dysplasia cases, suggesting that early treatment is desirable. Roux-Goldthwait procedure for treatment before closure of the epiphyseal growth plate may be useful for distal realignment not requiring osteotomy. However, poor outcomes have been reported in some cases treated with this procedure alone, so modified Roux-Goldthwait procedure by combination with vastus medialis advancement and lateral retinaculum release, and a favorable outcome was achieved. However, stabilization is difficult even with the modified Roux-Goldthwait procedure in cases with muscle weakness and hypotonia, showing that the indication is limited. Flexible procedures including MPFL reconstruction are also needed for cases with an open epiphyseal growthplate.
Conclusion: Treatment of habitual patella dislocation before closure of the epiphysea growth plate with stabilization using a modified Roux-Goldthwait procedure resulted in a favorable short-term postoperative outcome.
