Large Soft-tissue Mass Formation After Revision Total Knee Arthroplasty: An Unusual Case of Adverse Reaction to Metal Debris and Review of the Literature

Abstract

We report about the rare case of a patient who developed large soft-tissue mass formations related with revision total knee arthroplasty which was implanted 4 years prior. Owing to suspected periprosthetic joint infection, the prosthesis was removed and the lesions were resected, resulting in severe soft-tissue loss and temporary arthrodesis using a poly(methyl methacrylate) spacer. Histological analysis revealed a type VI periprosthetic membrane. The situation was further complicated by wound infection requiring multiple revision surgeries. After discussion and evaluation of the available treatment options, the decision for an above-the-knee amputation was made. The tissue reaction resulting in these soft-tissue lesions is referred to as an "adverse local tissue reaction." Wear-induced lesions after total knee arthroplasty, especially of this magnitude, are very rare and difficult to treat.

Keywords: ALTR; Metalosis; Periprosthetic joint infection; Revision; Total knee arthroplasty.

Figure 1

Failure of initial TKA leading to revision surgery with a rotating hinge prosthesis (Solution RT Modular; Smith&Nephew).

Figure 2

Presentation of the patient with 2 large pseudocysts popliteally and anterolaterally.

Figure 3

Conventional radiograph of right knee at patient presentation in our outpatient department in 2018 showing a well-fixed implant but osteolysis around the femoral epicondyles.

Figure 4

CT scan of the right knee: osteolysis of the femoral epicondyles leading to the erosion and fracture. Soft-tissue masses popliteally (depicted with “∗”) and anterolaterally (depicted with “#”).

Figure 5

Intraoperative finding of the soft-tissue mass (yellow-gray structure) and neurovascular structures during resection through a posterior approach in the lateral decubitus position. The upper vessel loop marks the peroneal nerve, whereas the lower loop depicts the sural nerve.

Figure 6

SLIM type VI: granulomatous pattern with accumulation of wear particles in cytoplasm of macrophages and giant cells (10x magnification); H&E.

Figure 7

SLIM type VI: granulomatous pattern with accumulation of wear particles in cytoplasm of macrophages and giant cells (40x magnification); H&E.

Figure 8

SLIM type VI: Fibrinoid necrosis; H&E.

Figure 9

Expanded SLIM classification according to Krenn and Perino [9].