Progressive Osteolysis with Hematoma Following Revision Total Hip Arthroplasty using Hydroxyapatite Mesh: A Case Report

INTRODUCTION: Osteolysis around the prosthesis following total hip arthroplasty (THA) is usually expanded slowly in the mid to long term, not progressive in the short term. Hematoma around the prosthesis is a rare phenomenon after a period of 1 year or more after surgery other than metal on metal THA. In addition, there are no studies reporting that hydroxyapatite (HA) itself has a possibility to cause osteolysis or hematoma after THA. This case has a particular disease phenomenon with three unusual factors, such as progressive osteolysis, hematoma, and HA debris in granulation tissue, following revision THA. CASE REPORT: A 79-year-old woman with pain in the left hip joint underwent a revision THA, using HA mesh and ultra high molecular weight polyethylene fiber cable for impaction bone grafting to fill a bone defect in the proximal femur in 2011. There were no abnormal findings clinically or on radiograph until 2014. Moderate osteolysis was observed at the lesser trochanter and the area distal to the greater trochanter on the radiograph in 2015. The synovial fluid culture was negative. On magnetic resonance imaging examination, the margin showed a low-density shell in both the T1- and T2-weighted images, and the inside was a mosaic mass, with mixed low- and high-density are as extending in a multidirectional manner. During surgery, cystic mass covered with a thick membrane was found around the artificial hip joint, and the inside of the capsule was full of solid and fluid hematoma and dark blood. There was no apparent wear and tear debris of the implant. On pathological examination, evidence of chronic hematoma, granulation tissue, and HA debris, interspersed inside the granulation tissue were observed. CONCLUSION: We experienced an extremely rare case with osteolysis and hematoma that progressively expanded in a short period of time after revision THA using HA mesh, which seemed to be caused by, crushed HA and resulted in osteolysis accompanied by hematoma. This case revealed that HA it has a possibility to cause osteolysis or hematoma after THA.