An impinging remnant meniscus causing early polyethylene failure in total knee arthroplasty: a case report

Abstract

The management of patients with an apparently normal functional total knee arthroplasty (TKA) suffering from unexplained persistent pain and swelling is a challenging issue. The usual causes of pain after total knee replacement are well known, but there are a small number of patients in whom its aetiology is obscure. Malfunction due to soft tissue impingement has rarely been reported. A patient with an unusual case of posterior soft tissue impingement secondary to a trapped posterior horn of a remnant medial meniscus after TKA and responsible for severe early polyethylene wear, is reported. The diagnosis was confirmed by arthroscopy. Treatment was performed by arthrotomy. The meniscus remnant was removed followed by total synovectomy and isolated exchange of the polyethylene insert. To our knowledge, this is the first well-documented case reporting this association. Case presentationA 63-year old male patient with a history of symptomatic osteoarthritis of the left knee underwent a Total Knee Arthroplasty (TKA) of posterior cruciate ligament retaining design (Kinemax, Stryker, Mahwah, New Jersey, USA) without a patella component. The postoperative course was uneventful. Three weeks later he presented to our out patient clinic with sudden swelling and discomfort of his left knee. Clinical examination demonstrated medial joint line tenderness and confirmed the patient's impression of joint effusion. Radiographs demonstrated a well-aligned TKA. All complaints, with exception of the knee effusion, declined progressively over a period of months. Two years postoperatively, the patient developed increasing pain and complained of "catching" of the knee. Physical examination showed a stable knee with a normal range of motion of 130 degrees flexion with no extension deficit. There was a moderate swelling and joint line tenderness medially. Standard radiographs showed a well-aligned TKA with no signs of loosening or polyethylene wear (Figure 1). Laboratory analysis including a complete blood count with differential, erythrocyte sedimentation rate, Creactive protein and knee aspiration for cell count and culture excluded infection. A technetium 99m diphosphonate bone scintigraphy showed an increased perfusion in the early phase and increased uptake in the static phase at the medial side of the femoral and tibial component and in the patella of the left knee (Figure 2).A diagnostic arthroscopy was performed to differentiate between a mechanical and a soft tissue related problem. Arthroscopy revealed a remnant of the posterior horn of the medial meniscus impinging between the posterior part of the femoral component and the polyethylene insert. There was also an important delamination of the anteromedial part of the insert with a crack at the ventral

Unique relationship between osteophyte and femoral-tibia component size mismatch in determining polyethylene wear in primary total knee arthroplasty: a case report

“…The clinical triad of effusion, pain and progressive change in the alignment of the knee which is characteristic of accelerated polyethylene wear [ 5 ] is not always seen. Some causes of pain reported in the literature after total knee replacement include remnant soft tissues [ 6 , 7 ], polyethylene wear, low-grade infection, loosening, malalignment and over-stuffing. The intermittent exacerbation of symptoms is secondary to intermittent synovitis [ 8 ].…”