Revision total hip arthroplasty: Cementless stems with bioactive coatings

Background: Revision total hip arthroplasty (THA) requires achieving primary stability to facilitate bone defect restoration and osseointegration. While various implant designs exist, the optimal strategy for managing femoral bone loss—ranging from standard stems to modular distal-locking devices—remains a subject of clinical discussion, particularly regarding the long-term efficacy of hydroxyapatite (HA) coatings in revision settings.

Objective: This article aims to delineate the surgical techniques and indications for cementless HA-coated stems in revision THA and to evaluate clinical and radiographic outcomes at a minimum follow-up of five years.

Key Points: Successful reconstruction relies on immediate axial and rotational stability through intimate host-bone contact. The surgical strategy utilizes a graduated approach: standard HA-coated stems for Paprosky types 1 and 2A, longer slotted stems for types 2 and 3A, and modular distal-locking devices for types 3B and 4. In a multicenter study of 347 hips using a long HA-coated monobloc stem, the 10-year Kaplan-Meier survival rate for aseptic stem revision was 99.3%. Radiographic analysis demonstrated significant bone stock restoration and high osseointegration scores (Engh score 16.4 ± 6.7). Complications included deep sepsis, periprosthetic fractures, and rare aseptic loosening. Preoperative planning and precise femoral preparation are essential to ensure adequate diaphyseal filling and prevent subsidence.

Conclusion: Long tapered cementless stems entirely coated with HA provide durable fixation and facilitate biological restoration of femoral bone stock. These implants offer reliable mid- to long-term clinical outcomes for complex femoral revisions across various degrees of bone deficiency.