Availability of Total Knee Arthroplasty Implants for Metal Hypersensitivity Patients

PURPOSE: To provide information on the type of “hypersensitivity-friendly” components available for primary total knee arthroplasty (TKA) in the current market. MATERIALS AND METHODS: Implant manufactures were identified using the 2013 National Joint Registries of the United Kingdom and Sweden and contacted to obtain information about the products they offer for patients with metal hypersensitivity. RESULTS: Information on 23 TKA systems was provided by 13 implant manufacturers. Of these, 15 systems had options suitable for metal hypersensitivity patients. Two types of “hypersensitivity-friendly” components were identified: 10 implants were cobalt chrome prostheses with a “hypersensitivity-friendly” outer coating and 5 implants were made entirely from non-cobalt chrome alloys. CONCLUSIONS: The results of this study suggest that several hypersensitivity TKA options exist, some of which provide the same designs and surgical techniques as the conventional implants. The information in this study can guide TKA surgeons in making informed choices about implants and identifying implants that could be examined in future controlled studies comparing outcomes between “hypersensitivity-friendly” and conventional implants.

Periprosthetic Mass after Total Hip Replacement / 대한고관절학회지

PURPOSE: To analyze the characteristics and causes of periprosthetic huge mass which occur after treatment by total hip arthroplasty. MATERIALS AND METHODS: Of the patients who had undergone total hip arthroplasty from January 2000 to October 2007, we retrospectively evaluated the 10 patients who suffered huge soft tissue mass. Five of these patients had received metal-on-metal bearing (group 1) prostheses, and the other 5 had received metal-on-polyethylene bearings (group 2). We evaluated the size and location of the mass, the extent of osteolysis, and the hematologic and pathologic examination results. RESULTS: Roentgenographically, the location of the masses varied from the acetabular area to the distal femoral stem. The mean mass diameter of all 10 patients was 14.6 cm(7-21 cm)x6.2 cm(3-9 cm)x7.2 cm(4-12 cm). Osteolytic lesions were found in 3 group 1 patients and 3 patients in group 2. High counts of lymphocytes and eosinophils were present in group 1. High counts of macrophages were present in group 2. CONCLUSION: The occurrence of osteolysis and huge soft mass after total hip arthroplasty is thought to be related to foreign body reaction by polyethylene wear particles and metal hypersensitivity. Outside-in patterned cortical thinning was considered to be indicative of a long standing periprosthetic soft tissue mass effect.