~ 800 ~ International Journal of Orthopaedics Sciences 2018; 4(2): 800-801 ISSN: 2395-1958 IJOS 2018; 4(2): 800-801 © 2018 IJOS www.orthopaper.com Received: 24-02-2018 Accepted: 25-03-2018 Mohamed Amine Triki Department of Orthopedics, Sahloul University Hospital University of Sousse, Sousse, Tunisia Sofien Benzarti Orthopedic Department, Sahloul University Hospital, Sousse, Tunisia Hamdi Kaziz Orthopedic Department, Sahloul University Hospital, Sousse, Tunisia Thabet Mouelhi Orthopedic Department, Sahloul University Hospital, Sousse, Tunisia Karim Bouattour Orthopedic Department, Sahloul University Hospital, Sousse, Tunisia Mohamed Laziz Ben Ayache Orthopedic Department, Sahloul University Hospital, Sousse, Tunisia Nader Naouar Orthopedic Department, Sahloul University Hospital, Sousse, Tunisia Correspondence Mohamed Amine Triki Department of Orthopedics, Sahloul University Hospital University of Sousse, Sousse, Tunisia Patellar clunk syndrome: A rare cause of painful knee after total knee arthroplasty Dr. Mohamed Amine Triki, Dr. Sofien Benzarti, Dr. Hamdi Kaziz, Dr. Thabet Mouelhi, Dr. Karim Bouattour, Dr. Mohamed Laziz Ben Ayache and Dr. Nader Naouar DOI: https://doi.org/10.22271/ortho.2018.v4.i2l.114 Abstract Although total knee arthroplasty is a successful procedure, postoperative residual knee pain after total knee arthroplasty is still the major factor that contributes to patient dissatisfaction. Even after resurfacing the patella, residual anterior knee pain is the most frequent complaint. Numerous etiologies have been associated with residual pain, including mid-flexion instability, aseptic loosening, infection, and patellar maltracking due to component malalignment. Other rare etiologies like patellar clunk syndrome could also cause residual knee pain after total knee arthroplasty. Through this case report of a patellar clunk syndrome successfully treated with arthroscopic resection, we discuss the etiopathogeny, diagnostic challenge, and treatment of this rare entity. Keywords: Arthroplasty, knee, clunk syndrome, arthroscopy Introduction In orthopedic surgery, Total knee arthroplasty (TKA) is one of the most successful surgeries. However, in terms of patient satisfaction, TKA is considered to be inferior to total hip arthroplasty [1] . Knee pain after TKA is the most common complaint. Usually it is the consequence of an infection or an aseptic loosening [2] . Sometimes, biological and radiological findings are normal, then a soft tissue impingement of different pathological entities, like the patellar clunk syndrome (PCS) should be suspected. Case report A 65-year-old man underwent right TKA in our orthopedic department for severe Knee osteoarthritis. Surgery was performed through a medial parapatellar approach under tourniquet control. Femoral, tibial and patellar components were cemented. Good patellar tracking was per-operatively obtained. The post-operative radiographs showed well-positioned components with good patellofemoral alignment on the skyline view. He had an uneventful post-operative recovery and the rehabilitation started immediately following surgery. At 8 weeks of follow-up he was satisfied with the clinical results with a good range of motion (0° to 120°) and a smooth patellar tracking. However, at 6 months of follow-up, he was feeling a clunk when he was trying to extend his knee around 30°. The symptomatology started about four months post-operatively beginning with a catching sensation that became a clunk over the next two months. At the clinical study, when extending the knee, a clunk was felt at 30° of flexion. Biology was within normal limits (white blood cells and c-reactive protein). Plain radiographs of the right knee showed well-positioned components without loosening or any evidence of instability. Arthroscopy was performed under general anesthesia, showing a fibrous nodule at the articular side of the junction between the quadriceps tendon and the resurfaced patella (Fig. 1). The nodule was resected arthroscopically using a shaver (Fig. 2). After debridement there was complete disappearance of the nodule and smooth patellar tracking without any clunk (Fig. 3). The patient was immediately relieved following the arthroscopy. At the last follow-up of 2 years he was completely satisfied, painless, with a good range of motion and no recurrence.