OBJECTIVETo compare the clinical results of single-stranded isometric with double-stranded anatomic reconstruction of medial patellofemoral ligament (MPFL) for recurrent patellar dislocation.

METHODSRetrospective analysis of 60 consecutive patients (72 knees) with recurrent patellar dislocation underwent medial patellofemoral ligament reconstruction between August 2004 and October 2008, 22 cases (27 knees) with single-stranded isometric reconstruction, 38 cases (45 knees) with double-stranded anatomic reconstruction. Postoperatively patellar stability was examined, and recurrent rate was recorded. Patellar lateral shift ratio and tilt were measured on CT scans. Knee function was evaluated with subjective questionnaire and the Kujala score.

RESULTSAll patients were followed up for more than 12 months without recurrent redislocation. (1) Recurrent instability rate was 18.5% in single-stranded group and 2.2% in double-stranded group, with statistical difference (P < 0.05). (2) The patellar tilt and lateral shift ratio returned to normal, without statistical difference between groups (P > 0.05). (3) The Kujala score were 59 ± 9 and 62 ± 9 preoperatively and 87 ± 4 and 94 ± 6 postoperatively in single- and double-stranded group, with statistical difference (P < 0.05). (4) The excellect rate was 85.2% in single-stranded group, 97.8% in double-stranded group, with statistical difference(P < 0.05).

CONCLUSIONBoth reconstruction can improve patellar stability and knee function significantly, with double-stranded anatomic reconstruction better in clinic evaluation.