Why compromise the patella? Five-year follow-up results of medial patellofemoral ligament reconstruction with soft tissue patellar fixation.

PURPOSE: This study investigates the redislocation rate and functional outcome at a minimum follow-up of five years after medial patellofemoral ligament (MPFL) reconstruction with soft tissue patellar fixation for patella instability. METHODS: Patients were retrospectively identified and knees were evaluated for trochlea dysplasia according to Dejour, for presence of patella alta and for presence of cartilage lesion at surgery. At a minimum follow-up of five years, information about an incident of redislocation was obtained. Kujala, Lysholm, and Tegner questionnaires as well as range of motion were used to measure functional outcome. RESULTS: Eighty-nine knees were included. Follow-up rate for redislocation was 79.8% and for functional outcome 58.4%. After a mean follow-up of 5.8 years, the redislocation rate was 5.6%. There was significant improvement of the Kujala score (68.8 to 88.2, p = 0.000) and of the Lysholm score (71.3 to 88.4, p = 0.000). Range of motion at follow-up was 149.0° (115-165). 77.5% of the knees had patella alta and 52.9% trochlear dysplasia types B, C, or D. Patellar cartilage legions were present in 54.2%. Redislocations occurred in knees with trochlear dysplasia type C in combination with patella alta. CONCLUSION: MPFL reconstruction with soft tissue patellar fixation leads to significant improvement of knee function and low midterm redislocation rate. Patients with high-grade trochlear dysplasia should be considered for additional osseous correction.

Handmade articulating spacer for two-stage exchange at the knee.

OBJECTIVE: Two-stage exchange with implantation of a temporary spacer is considered gold standard treatment for chronic periprosthetic joint infection of the knee. This article describes a simple and safe technique for handmade articulating spacers at the knee. INDICATION: Chronic or relapsing periprosthetic joint infection of the knee. RELATIVE CONTRAINDICATIONS: Known allergy against components of polymethylmethacrylate (PMMA) bone cements or admixed antibiotics. Inadequate compliance for two-stage exchange. Patient not able to undergo two-stage exchange. Bony defect situation at the tibia or femur leading to collateral ligament insufficiency. Soft tissue damage with need for plastic temporary vacuum-assisted wound closure (VAC) therapy. SURGICAL TECHNIQUE: Removal of the prosthesis, thorough debridement of necrotic and granulation tissue, tailoring bone cement with antibiotics. Preparation of a tibial and femoral stem. Customizing the tibial and femoral articulating spacer components to bony anatomy and soft tissue tension. Confirmation of correct position by intraoperative radiography. POSTOPERATIVE MANAGEMENT: Protection of the spacer with an external brace. Restricted weight-bearing. Passive range of motion as possible. Intravenous-followed by oral antibiotics. Reimplantation after successful treatment of infection.