[Recurrent dislocation of the patella--arthroscopic therapy]

The authors present results of the surgical treatment of the recurring patella dislocation. They use the surgical technique of medial percutaneous raphe by absorbable PDS suture and lateral release with arthroscopis assistance.

The operation was performed for recurring dislocation in 19 cases in 16 patients. Three patients underwent a surgery on both knees. The average age of patients was 22 years (range, 14-29 years). The average period after the surgery was 22 months (range, 12-45 months). Minimal number of dislocations prior to operation was 3, maximal more than 20.

The surgical technique consists in medial raphe by percutaneously inserted absorbable PDS suture with arthroscopic assistance and in performing a lateral release in the "closed manner" under the check of the arthroscope. After-care consists in the application of a rigid orthesis which is starting from the first postoperative day removed for physiotherapy by CPM. After two weeks a hinged orthesis is used with a gradual increase of the range of motion. After 6 weeks the patient starts full weightbearing without any fixation. The authors evaluated the results of the operation after Bentley. They also followed the duration of turniquet of the operated on limb, the duration of hospitalization and the period necessary for the achievement of the full range of motion. Radiograph was used for the determination of the shape of patella after Baumgartl and Wiberg, the angle of the femoral sulcus, the height of patella after the Insall-Salvati index and lateral shift of patella. Arthroscopic examination focused on the evaluation of the patellar and femoral chondromalacy and its classification after Outerbridge. Clinically, Q angle was measured, the axis of the limb, anxiosity test was made and the presence of crepitation was checked.

Ninety per cent of the patients evaluated the condition after the surgery as very good or good, twice as poor. In one patient there occurred one recurrence of dislocation after the surgery. In the second patient after the surgery pain aggravated in connection with a severe degenerative damage of the femoropatellar joint. Neither avascular necrosis of the patella nor any more extensive bleeding was encountered. There was no infectious complication in the group of patients. Chondral lesion was recorded in 80% of patients. The degree of the damage increased with the number of dislocations. A frequent complication was a recurring knee effusion with the necessity of its evacuation. The relation between the number of dislocations and the final outcome of the surgery was proved. No patient with the number of dislocations 10 and more was evaluated as excellent.

AS release and medial raphe is a surgical technique which brings very good and good results in a high number of patients. Independently performed raphe or release do not have comparable good results in the therapy of recurring dislocation. The authors' results do not differ from data in specialised literature.

Arthroscopically performed lateral release and medial raphe by percutaneously inserted suture and with AS assistance has a number of unquestionable benefits. The performance is associated with only minimum complications. It reduces the duration of hospitalization, immobilization of the limb, duration of physiotherapy as well as the total duration of the incapacity to work. The cosmetic result is good. It is possible to operate on also on young patients prior to the final ossification in the area of the tibial tubercle. A prerequisite of a good result is an accurate performance of the operation and subsequent physical therapy. Contraindications include marked degenerative changes in the femoropatellar joint, instability of the knee, patella dislocation in TKR. Q angle exceeding 30 degrees and valgus deformity of the limb exceeding 15 degrees. A high number of dislocations and the resulting more severe damage to the cartilage reduce the potential for achieving excellent results.