Medium-term outcome of the Libra® cemented versus cementless stems in primary dual mobility total hip arthroplasty

Abstract

Introduction: Despite the increasing use of cementless stems in total hip arthroplasty, the cemented stem has played a valuable role in the armamentarium of orthopedic surgeons. This study aims to compare two types of Libra® stems SERF, one cemented (Libra® C) and the other cementless hydroxyapatite coated (Libra® HA) that were conducted to analyze the medium-term outcome regarding their behavior and longevity.

Methods: This is a retrospective study for patients who received primary total hip arthroplasty with Dual Mobility (DM) articulation in the period between January 2014 to January 2020 with a minimum of two years follow-up. Two-hundred hips have been identified in 196 patients. One hundred forty-three Libra® cementless versus fifty-seven Libra cemented stems were implanted and the outcome of these stems is reported. All procedures were performed through the posterior approach and cemented stems were selected for elderly patients with wide medullary canals Dorr Type C. The indications for the index procedure were fractures, avascular necrosis, rheumatoid, and osteoarthritis. One hundred thirty-nine cementless DM cups were used while sixty-one hips had cemented Novae stick cups. Radiological evaluation for cup and stem positions, cement mantle, and radiolucent lines was performed, besides clinical function using the Harris Hip Score.

Results: The average age of patients was 60 ± 14.8. At the latest review, none of the cemented stems was revised or awaiting revision. One cementless stem was revised because of cortical perforation. Five intraoperative fractures were observed in the cementless group, but none of them needed revision or affected the stem stability. Readmission to theatre occurred in four patients to evacuate hematoma in two, a reduction of dislocation in one, and grafting bone lysis in one.

Conclusion: Cemented stems have an important role in osteoporotic patients with wide medullary canals with excellent outcomes and minimal risk of fracture.

Level of evidence: Level IV.

Keywords: Cemented; Cementless; Dual mobility, libra®; Total hip arthroplasty.

Fig. 1

(A) Libra® standard offset uncemented stem (B) Libra® standard offset cemented stem

Fig. 2

Fully cemented Dual Mobility THA in a 73-year-old male that was performed 4 years before for fracture NOF that shows stable cement mantle with no evidence of loosening on the femoral or acetabular sides

Fig. 3

32-year-old male patient had THA for secondary arthritis post-Perthes’ disease. (A) preoperative x-ray that shows the proximal femoral deformity and plate used for varus osteotomy in his childhood (B) immediate post-operative x-ray with Libra cementless stem inserted through the site of previous deformity and screw holes evident around distal part of the stem. (C) 4 years post-operative with stem integration and filling of bone defects

Fig. 4

53 years old male patients who had hip arthritis secondary to septic arthritis in childhood and pelvic support osteotomy (A) preoperative x-ray with advanced arthritis limb length discrepancy and valgus position of the proximal femur (B) Libra cementless stem and Novae® E TH DM cup, intraoperative crack of the proximal femur during stem insertion was observed and protected with wires (C) 3 years post-operative with full bone ingrowth around the stem

Fig. 5

46 years female patient who had THA with cementless stem and Novae® E TH cup (A) 3 years post-operative started to develop cysts around the cup flange (B) 1 year after the bone graft using the trap door technique