Long-Term Results of Surgical Treatment of a Patient with Congenital Patellar Dislocation

OBJECTIVES: Congenital dislocation of patella (CDP) is a condition which is often associated with disorders of quadriceps mechanism. CPD may occur as flexion contracture of knee which are associated with syndromes, and also may occur in different forms as an isolated anomaly which are characterized by dislocation of patella by flexion or extension of knee or spontaneously reduction of patella. Here, we aimed to present the long-term results of a case of CPD which is occurred as an isolated anomaly. METHODS: A seven years old male patient admitted with the complaints of limitation in the right knee joint and difficulty in walking. Physical and radiological examinations of the patient were performed, and patient hospitalized with CPD preliminary diagnosis. The right knee joint flexion and extension range of motions were significantly limited when compared with left knee joint. Range of motion of knee flexion was 100° and limitation of extension was 30°. Also the patient had difficulty in walking due to weakness of extensor mechanism. The patella located laterally to the lateral femoral condyle, and it was in fixed position by palpation. Reduction of patella wasn’t achieved by passive flexion and extension of knee. The patella was sited laterally to the lateral femoral condyle in anteroposterior (AP) knee radiography. And in tangential radiography; it was seen that the patella dislocated to the lateral side. And also, there was insufficiency in the development of patellar femoral surface, and trochlear dysplasia was observed. According to these physical and radiological findings patient was operated with the diagnosis of CPD and modified Roux-Goldthwait surgical technique was performed. Postoperatively patient followed in long leg cast that is performed in 30° knee flexion and internal rotation. Any complications were not seen at the follow-up of patient. RESULTS: Patient was followed nearly 6 years. At the last follow-up it was seen that range of motions of knee joint reached to normal degrees. And in AP radiography; it was seen that patella is in anatomic location. Also tangential radiography showed that patella is in accordance with patellar femoral surface. Interestingly, the trochlear dysplasia was improved and gained its normal anatomic structure. CONCLUSION: CPD is a rare congenital anomaly of the knee. It may frequently accompany with syndromes, and also may appear isolated anomaly. The functional effects can cause various symptoms. Appropriate surgical treatment is effective in the improvement of functions and instability.