An 18-year-old girl presented to us with recurrent dislocation of patella. She had two previous surgeries, first one at the age of 16 years and the second surgery a year later, in two different hospitals. Lateral release and medial plication was done in 2007 and extensive lateral release and vastus medialis advancement was done in 2008. Unfortunately, the problem persisted and the patella continued to dislocate when she presented to us. On clinical and radiological examination, she had generalized ligamentous laxity, apprehension test was positive and the medial patellar glide was <1/4, indicating a tight lateral retinaculum. Tibial tubercle- trochlear groove (TT-TG) distance, a measure of Quadriceps angle by CT scan was 23.2 mm. Patella alta measurement by Caton Deschamps's index was 1.2. CT showed Patellar tilt angle of 43 degrees, Type ‘C’ Dejour's trochlear dysplasia ie. lateral femoral convexity and medial femoral hypoplasia [Figures –].\nShe underwent sulcus deepening trochleoplasty as described by Dejour and medial patellofemoral ligament (MPFL) reconstruction along with lateral retinacular release. Through a midline skin incision and medial parapatellar arthrotomy, the trochlea was exposed under tourniquet control. The peritrochlear periosteum and synovium were incised about 5 mm from the trochlear cartilage margin. This width of 5 mm of the bone will correspond to the prominence of the trochlea (distance between the anterior cortex of the femur and the boundary of the trochlear cartilage). The cortex was osteotomized in the same plane and an osteochondral flap of about 5 mm thick was raised in “V” shape. The trochlear sulcus was referenced off the intercondylar notch, and was mapped proximally and 6° laterally. A thin layer of cancellous bone was removed with a curette up to the notch, more in the middle of the trochlea. The trochlear bone shell was impacted into the trough created in the cancellous bone. However, the sulcus formed was not deep enough. Hence, to achieve sufficient correction, we split the cartilage along the center of the groove. The newly established trochlea was fixed with two small staples astride the osteochondral junction, one on either side of the groove. There was no impingement as the knee was taken through its range of motion. The peritrochlear periosteum and the synovium were sutured.\nAfter this procedure, we reconstructed the MPFL, as described by Erasmus, but with a few variations. A double-looped semitendinosus tendon was anchored to the medial border of patella at the junction of upper and middle thirds, typically where the perimeter of patella becomes more vertical with a titanium anchor. A tunnel was drilled at the isometric point on the medial femoral epicondyle through which the tendon was pulled through and was fixed with a biodegradable interference screw []. Medial patellar retinaculum was repaired at this ligament. Lateral retinacular release was done from inside out prior to the reconstruction of medial patella ligament since medial patellar glide was restricted in our patient. Since the new trochlear groove was angled at 6° laterally, distal realignment by tibial tubercle osteotomy was not done.\nA hinged knee brace to allow 30° flexion was used for 3 weeks. Daily knee flexion exercises were allowed. Weight bearing was allowed from the first day using crutches.\nOne year following the surgery, she had slight medial parapatellar tenderness and no patellar apprehension. Presently, terminal 5° of flexion is restricted. Radiological signs of trochlear dysplasia were corrected and patellar tilt angle improved from 48° to 18° . Kujala score improved from 52 to 80 points. Staples were removed 1 year after surgery. Near-normal looking trochlea surface was seen in postoperative computed tomography (CT) scan and during arthroscopy [].
26 year old man who is a railway employee presented with left anterior knee pain and frequent dislocation of the patella since 3 months. To start with he fell down and twisted his knee while climbing down a ladder for which he visited a physician and was diagnosed to have left patella dislocation that was treated by immobilization in a long leg knee brace for 3 weeks. He had frequent anterior knee pain and frequent dislocations of the patella (probably 6) which were less painful than the primary episode and were self reducible. The patient was evaluated in the OPD, there was diffuse swelling and tenderness over medial patellofemoral joint, a positive apprehension test, no hyperlaxity and a Q-angle of 15°. Radiographs showed lateral patellar tilt, lateral patellar subluxation, sulcus angle 136° [] and Insall-Salvatti Index-1.1 []. MRI showed efussion of knee joint with tear in the MPFL at the patellar attachment. Of note, he had no other surgeries performed to the same knee. A preprocedure arthroscopy showed patellofemoral joint maltracking.\nThe patient was treated definitively with MPFL reconstruction by the technique described by us. He returned to work in 6 weeks, at 24-month follow up, Modified Crosby and Insall scale was excellent and Kujala score was 95.