Abstract
BACKGROUND: Extensor apparatus rupture is a severe complication after knee arthroplasty, but there have not been many reports on how to perform knee arthroplasty after chronic patellar ligament rupture. We reported a case of total knee arthroplasty (TKA) in a patient with severe osteoarthritis (OA) complicated by chronic patellar ligament rupture. CASE PRESENTATION: In this case, a 67-year-old male patient suffered from patellar ligament rupture due to trauma more than 20 years ago and did not undergo any formal treatment. Physical examination revealed a small amount of fluid and extension lag, and the patella was displaced upward by approximately 5.5 cm. The quadriceps were atrophic and weak. There was significant tenderness on the medial side of the left knee joint. Passive motion of the left knee joint ranged from full extension to 120° of flexion with discomfort during excessive flexion. Active flexion of the knee joint to 120°, and extensor lag was approximately 90°. We reconstructed the extensor apparatus through a quadriceps tendon V-Y quadricepsplasty and Krackow suture technique of the patellar ligament, and osteoarthritis was resolved with TKA. The visual analogue scale (VAS) score decreased from 5 points to 1 point after surgery. Six weeks later, the patient was able to walk normally without a walking stick, and the knee joint could stretch actively to approximately 30°. However, he had obvious extension lag. This problem improved 10 months after surgery. The AKS score increased from 35 to 95 10 months after surgery. The HSS score increased from 43 to 93. CONCLUSIONS: TKA and ligament reconstruction are options for the treatment of knee OA with chronic patellar ligament rupture. V-Y lengthening of the quadriceps femoris tendon after the Krackow suture technique of the patellar ligament with transpatellar tunnels may be a reasonable choice during TKA.