Background: We occasionally noticed excessive distal plug position in our clinical routine of cemented hip arthroplasties. We therefore performed an analysis of risk factors for migration of a biodegradable intramedullary gelatine plug.
Patients and methods: The performance of a cement restrictor was studied in 100 consecutive cemented total hip arthroplasties implanted with third-generation cementing techniques. In a radiographic analysis anatomical parameters, cement mantle quality, and mechanisms and factors for restrictor failure were evaluated.
Results: 40 restrictors showed inadequate performance: 5 cases of tilting, 22 cement leakages, 16 excessive migrations, 2 excessive migrations plus leakages, and 1 case of leakage plus tilting. excessive migration (< 5 cm) was more common in large intramedullary canals (p = 0.04) and cement leakage was more common in patients with a proximally located isthmus (p = 0.04). Half of the hips showed a complete or almost complete filling of the intramedullary cavity, which was more often found in operations carried out by experienced surgeons.
Interpretation: A more reliable plug design should be considered for patients with wide intramedullary canals and a high isthmus, to minimize the risk of plug migration and poor cement mantle quality.