Objective To investigate the procedure and effectiveness of medial patellofemoral l igament (MPFL) reconstruction for the treatment of recurrent patellar dislocation. Methods Between June 2005 and September 2007, 29 patients with recurrent patellar dislocation underwent MPFL reconstruction with allograft semitendinosus or allograft anterior tibial is tendon. There were 6 males and 23 females with an average age of 20.3 years (range, 13-45 years). The patients sufferedfrom 2-10 times patellar dislocation preoperatively. The average time between last dislocation and surgery was 43.9 months (range, 1-144 months). CT scan was performed to measure the tibial tuberosity-trochlear groove distance (TT-TG). The femoral tunnel was made at the origin of MPFL insertion, just inferior to the medial epicondyle. The double L-shape patellar tunnels were made on the medial rim of patella with 4.5 mm in diameter. The loop side of the graft was fixed with a bioabsorbable interference screw in the femoral tunnel both ends of the graft. For the TT-TG was more than 20 mm, a modified Elmsl ie-Trillat osteotomy was performed to correct the distal al ignment of patella. The arthroscopic examination was also performed for loosebody and lateral retinacular release. Results Twenty-seven patients were followed up 45.5 months on average (range, 40-67 months). No recurrent dislocation or subdislocation occurred. All the patients showed negative apprehension test at 0° and 30° flexions of knee. The range of motion of knee restored normal 1 year after operation. The Kujala score was improved from 72.03 ± 17.38 preoperatively to 94.10 ± 7.59 postoperatively, and Lysholm score was improved from 72.65 ± 14.70 to 95.44 ± 6.25, both showing significant differences (P lt; 0.05). The Tegner score was decreased from 5.25 ± 1.83 preoperatively to 4.33 ± 1.00 postoperatively, showing no significant difference (t=1.302, P=0.213). In patients whose TT-TG was more than 20 mm, TTTG was decreased from (23.38 ± 3.70) mm to (16.88 ± 5.92) mm at last follow-up, showing significant difference (t=2.822,P=0.026). Conclusion The technique of MPFL reconstruction is an effective surgical procedure for the treatment of recurrent patellar dislocation, which can improve the patella stabil ity and knee function.
ObjectiveTo study the effect of the femoral tunnel position on the knee function recovery after medial patellofemoral ligament (MPFL) reconstruction. MethodsA retrospective analysis was made on the clinical date of 43 cases (43 knees) of recurrent patellar dislocation undergoing MPFL reconstruction and patellofemoral lateral retinaculum lysis between August 2013 and March 2014. There were 12 males and 31 females, aged 19.4 years on average (range, 9-35 years). All patients had trauma history and recurrent dislocations. The results of apprehesion test and J syndrom were positive. The patellar tilt test showed patellofemoral lateral retinaculum was tension. The effectiveness was evaluated using Lysholm knee functional score after operation. The distance from the center of the femoral tunnel to the femoral isometric point was measured on CT three dimensional reconstruction image. Whether the femoral tunnel position was isometric was evaluated. The correlation was analyzed between the distance from the center of the femoral tunnel to the femoral isometric point and Lysholm score. ResultsPrimary healing of incision was obtained in all patients. The patients were followed up 13-18 months (mean, 15 months). No patellar dislocation or subluxation occurred. The result of apprehensive test was negative. At last follow-up, the average Lysholm score was 93.8 (range, 83-100). The average distance from the center of the femoral tunnel to the femoral isometric point was 5.61 mm (range, 2-16 mm). The femoral tunnel position was isometric in 30 cases (69.8%) and non-isometric in 13 cases (30.2%). The distance from the center of the femoral tunnel to the femoral isometric point was negatively correlated with postoperative Lysholm score (r=-0.851, P=0.000). The postoperative Lysholm score was 95.7±2.3 in patients with isometric tunnel and was 89.4±3.5 in patients with non-isometric tunnel, showing significant difference (t=6.951, P=0.000). ConclusionFor patellofemoral joint instability, preparing the femoral isometric tunnel can establish a good foundation for the recovery of the knee function in MPFL reconstruction.