Long-term Follow-up and Knee Osteoarthritis Change After Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Dislocation

¹ Department of Orthopaedic Surgery, Saitama Municipal Hospital, Saitama, Japan
² Department of Orthopaedic Surgery, Isehara-Kyodo Hospital, Isehara, Japan
³ Department of Orthopaedics and Rehabilitation Medicine, Fukui University School of Medicine, Fukui, Japan

^* To whom correspondence should be addressed. E-mail: edknom{at}nifty.com.

	Abstract

Background: Proximal or distal realignment procedures have long been selected as treatment for recurrent patellar dislocation, but associated knee osteoarthritis has been a substantial problem that leads to poor results. A new approach, medial patellofemoral ligament reconstruction, has recently started, but there have been no reports on the long-term follow-up.

Hypothesis: Anatomical medial patellofemoral ligament reconstruction can lead to satisfactory long-term outcome and a low association rate of knee osteoarthritis.

Study Design: Case series; Level of evidence, 4.

Methods: Twenty-four knees from 22 patients who underwent medial patellofemoral ligament reconstruction for recurrent patellar dislocation were reviewed at a mean follow-up of 11.9 years (range, 8.5-17.2 years). A lateral release was done on 14 of 24 knees. The clinical/physical outcome and the association of knee osteoarthritis were investigated. Patellofemoral and femorotibial osteoarthritis on the radiographs was evaluated using the Crosby/Insall and the Kellgren/Lawrence grading systems.

Results: According to the Crosby/Insall criteria, 11 knees (46%) were classified as excellent, 10 (42%) as good, 3 (12%) as fair/poor, and none as worse at follow-up. Further lateral subluxation or dislocation occurred in only 2 knees. The mean Kujala score improved significantly from 63.2 points preoperatively to 94.2 points at follow-up (P < .0001). According to the Crosby/Insall grading system, patellofemoral osteoarthritis was none to mild in 23 of the 24 knees and moderate in 1 knee, preoperatively. At the final follow-up, 21 knees were none to mild, and 3 knees were moderate. There were only 2 knees that had definite progression from none to mild to a moderate grade.

Conclusion: The association of definite knee osteoarthritis in medial patellofemoral ligament reconstruction with or without lateral release was small in the long-term follow-up. The conclusion is that medial patellofemoral ligament reconstruction not only prevents further patellar dislocation but also shows no or only slight progression of knee osteoarthritis.