Secondary cement injection technique reduces pulmonary embolism in total hip arthroplasty.

PURPOSE: Cardio-pulmonary damage due to embolism is a feared complication of cemented hip arthroplasty and can be fatal. Embolic events result from an increased intramedullary pressure during cement and stem insertion and can lead to extrusion of bone-marrow elements into the circulation. To reduce embolism and at the same time achieve an ideal cement mantle, the cement injection stem has been designed. In contrast to conventional stems where cement applied before stem insertion (primary cementing technique), the cement injection stem is positioned first and only then is the cement injected via the stem in a volume- and pressure-controlled fashion (secondary cementing technique). METHODS: A randomised trial with 30 patients was performed to evaluate whether this technique is able to reduce embolic events. Patients either received a conventional cemented stem (primary cementing technique) or a cement injection stem (secondary cementing technique). Embolic events were recorded by transesophageal echocardiography at six specific points during the operation and classified from grade 0 to grade 3. RESULTS: Significantly fewer grade 2 and 3 embolic events were observed in patients receiving the cement injection stem using the secondary cementing technique. Moreover, in the conventional group all patients (100 %) had at least one grade 3 embolus whereas only 20 % with the secondary cementing technique had an embolic event of grade 3. CONCLUSION: Secondary cement insertion via the cement injection stem is able to reduce severe embolic events significantly. The technique offers a more gentle cementing technique and therefore appears especially beneficial for patients of advanced age and/or with pre-existing cardio-pulmonary comorbidities.

Long-term results of 58 hip cup revision arthroplasties using a threaded ring implant.

INTRODUCTION: There is still a discussion whether cementless hip cup revisions should be performed with a press fit cup or a threaded ring implant. MATERIALS AND METHODS: The results of 58 hip cup changes using the spherical, threaded ring "Munich" are presented. In 16 cases, the ring "Munich I" with a smooth surface and in 42 cases the ring "Munich II" with a corundum-blasted surface were implanted. Mean follow-up was 7.5 years; radiological signs of loosening and the Harris Hip Score were examined. RESULTS: The re-revision rate for aseptic loosening of the ring was 12/58 overall (Munich I: 5/16, Munich II: 7/42). The average Harris Hip Score was 76.2 overall (Munich I: 74.4, Munich II: 76.8). Higher survival rates were achieved with the "Munich II" ring due to improved construction details. CONCLUSION: These rates are still below those reported for press-fit cups, the technique described by Slooff or reinforcement rings.