RESUMEN
Background: When a periprosthetic infection is diagnosed, the surgical treatment is usually performed as soon as possible to avoid further bone damage or life threatening complications. There is no report on the radiographic change in patients with untreated infected total hip arthroplasty (THA) for several years. Objective: Report radiographic change in patients with untreated infected THA. Method: Two patients presented with chronic septic loosening of cemented acetabular fixation after total hip replacement at King Chulalongkorn Memorial Hospital. Both patients had mild hip pain and had been lost for follow-up until the bone destruction became very severe. Serial radiographs after the surgeries were evaluated. The Paprosky’s acetabular bone loss classification was used to classify the radiographic findings. Results: Based on the Paprosky’s classification for acetabular bone loss, there were two similar atypical radiographic findings found in both patients. These included pelvic discontinuity from extensive medial acetabular bone loss beyond the Kohler’s line, and minimal superior and inferior acetabular bone loss. Conclusion: These atypical radiographic findings were rarely observed in septic acetabular loosening patients, as infection usually causes patients to present earlier. Following the septic acetabular loosening of THA, surgical procedure should be performed before massive bone damage was demonstrated.
RESUMEN
PURPOSE: To observe the amount and distribution of overflown cement on the backsurface of the glenoid prosthesis and to determine the amount of cement required for ideal fixation of the glenoid prosthesis. MATERIALS AND METHODS: 48 keeled type glenoid prostheses (Global total shoulder, Depuy Co., U.S.A.) were fixed with four different volumes of cement (fully filled in the slots, and cement removed to depths of 4, 7 and 10 mm) to the scapulae of mature pigs, in which 46 scapulae that could be freed from the prostheses were investigated in terms of the amount and distribution of the leaked cement by gross inspection and evaluation using Arc view GIS 8.1. RESULTS: The cement overflowed in an irregular fashion. The average ratio of the area covered by leaked cement to glenoid surface was 30.7% (12.9-52.2) in 27 cases, in which the slots were completely filled by cement; 19% (13.4-29.9) in 6 cases in which a 4 mm depth of cement was removed from the slots; 1.8% (-7.5~16.8) in 8 cases in which a 7 mm depth of cement was removed from the slots; -10.2% (-15.8~-5.2) in 5 cases in which a 10 mm depth of cement was removed from the slots. CONCLUSION: It is impossible to prevent leakage of cement behind the backsurface of the glenoid prosthesis with the conventional cemented fixation method. This can be prevented by removing the equivalent amount of cement before inserting the prosthesis.