抄録
In total knee arthroplasty (TKA), the patellofemoral articulation is still a source of various complications such as anterior knee pain, patellar fracture and dislocation of the patellar component. Patellar clunk syndrome (PCS) is another of these complications, and arises through impingement of soft tissue under the patella. Here we describe a case of PCS in a 63-year-old woman with rheumatoid arthritis (RA), who underwent minimally invasive TKA (MI-TKA) via a mini-mid vastus approach. Four months after the operation, she became aware of painful catching in the knee, and was diagnosed as PCS under arthroscopic inspection. Arthroscopic debridement was performed to remove a fibrous nodule in the intercondylar notch of the femoral component (PFC Sigma RP-F, DePuy), and this symptom was relieved. It has sometimes been reported that in MI-TKA the visualized area is insufficient, especially under the quadriceps tendon. In the present case, resection of soft tissue around the patella may have been inadequate, and/or synovial proliferation of RA may have recurred. Furthermore, in this procedure, care must be taken to avoid any increase in the posterior tibial slope in order to prevent anteroposterior instability, especially in the deep flexion femoral component design, as this may cause inflammation around the patellofemoral joint.
