[ROLE OF TIBIAL TUBERCLE INTERNAL ROTATION TO TREAT RECURRENT PATELLAR DISLOCATION ASSOCIATED WITH TROCHLEAR DYSPLASIA].

OBJECTIVE

To introduce and analyze the role of tibial tubercle internal rotation to treat recurrent patellar dislocation associated with trochlear dysplasia.

METHODS

Between February 2007 and April 2011, 28 patients with recurrent patellar dislocation underwent tibial tubercle translocation through medial transfer, rotation and elevation of the tibial tuberosity and the medial patellofemoral ligament (MPFL) reconstruction. There were 4 males and 24 females with an average age of 21.8 years (range, 17-28 years). The disease duration ranged from 6 months to 8 years (mean, 4 years). The patients suffered from 3-10 times patellar dislocation. The result of apprehension test was positive; Lysholm score was (51.64 ± 3.79); Kujala score was (56.89 ± 3.79). According to Dejour classification, 11 cases were rated as type B, 14 cases as type C, and 3 cases as type D; the tibial tuberosity-trocholear distance (TT-TG) was (20.53 ± 2.58) mm; and the patellar tilt angle (PTA) was (29.34 ± 2.54)°.

RESULTS

Primary healing of incision was obtained in the others except 1 case of mild infection. Twenty-seven patients were followed up 41.8 months on average (range, 27-74 months). No recurrent dislocation was found, and the result of apprehension test was negative. The knee range of motion restored to normal totally. The postoperative Kujala score and Lysholm score were significantly improved to 88.97 ± 3.06 and 88.95 ± 2.98 (t = -42.005, P = 0.000; t = -43.122, P = 0.000) respectively. TT-TG and PTA restored to normal [(11.77 ± 2.24) mm and (7.99 ± 2.57)°], showing significant differences when compared with preoperative ones(t=13.032, P=0.000; t=29.533, P=0.000).

CONCLUSION

The technique of tibial tubercle translocation and MPFL reconstruction is an effective surgical procedure for the treatment of recurrent patellar dislocation associated with trochlear dysplasia. Especially, tibial tubercle internal rotation can improve the patella stability and knee function.