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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 63 - 63
19 Aug 2024
Tsikandylakis G Mortensen KRL Gromov K Mohaddes M Malchau H Troelsen A
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Vitamin E-doped cross-linked polyethylene (VEPE) has encouraged the use of larger heads in thinner liners in total hip arthroplasty (THA). However, there are concerns about wear and mechanical failure of the thin liner, especially when metal heads are used. The aim of this randomized controlled trial was to investigate if the use of a large metal head in a thin VEPE liner would increase polyethylene wear compared with a standard 32-mm metal head and to compare periacetabular radiolucencies and patient-reported outcomes in THA.

96 candidates for uncemented THA were randomly allocated to either the largest possible metal head (36–44 mm) that could be fitted in the thinnest available VEPE liner (intervention group) or a standard 32-mm metal head (control group). The primary outcome was proximal head penetration (PHP) measured with model-based radiostereometric analysis (RSA). Secondary outcomes were periacetabular radiolucencies and patient-reported outcomes. The mid-term results of the trial at 5 years are presented.

Median total PHP (interquartile range) was -0.04 mm (−0.12 to 0.02) in the intervention group and -0.03 mm (=0.14 to 0.05) in the control group (p=0.691). The rates of periacetabular radiolucencies were 1/44 and 4/42 (p=0.197), respectively. Patient-reported hip function and health-related quality of life did not differ between the groups, but participants in the intervention group reported a higher level of activity (median UCLA rank 7 vs 6, p=0.020). There were 5 revisions caused by dislocations (2), periprosthetic fracture (1), stem subsidence (1), or iliopsoas impingement (1).

Large metal heads in thin VEPE liners did not increase liner wear and were not associated with liner failure 5 years after THA.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 34 - 34
23 Jun 2023
Bunyoz KI Tsikandylakis G Mortensen K Gromov K Mohaddes M Malchau H Troelsen A
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In metal-on-polyethylene (MoP) THA large femoral metal heads are designed to increase stability and to reduce dislocation risk. The increased head size could lead to increased taper corrosion with the release of metal ions and adverse reactions. Using blood ion measurements, we aimed to investigate the association between femoral head size and metal-ion release after MoP THA.

96 patients were enrolled at two centers and randomized to receive either a 32-mm metal head or a 36–44 mm metal head (the largest possible fitting the thinnest available polyethylene insert). Blood metal ions and PROMs (OHS, UCLA) were measured at two- and five-year follow-ups.

Both 2- and 5-year median chrome, cobalt, and titanium levels were below taper corrosion indicative ion levels. At 5 years, median chrome, cobalt, and titanium levels were 0.5 μg/L (0.50–0.62), 0.24 μg/L (0.18–0.30), and 1.16 μg/L (1.0–1.68) for the 32-mm group, and 0.5 μg/L (0.5–0.54), 0.23 μg/L (0.17–0.39), and 1.30 μg/L (1–2.05) for the 36–44 mm group, with no difference between groups (p=0.825, p=1.000, p=0.558). At 2 years, 7 (32-mm) versus 4 (36–44-mm) patients had elevated ions. At 5 years, 6 (32-mm) versus 7 (36–44-mm) patients had elevated ions. There was no difference in either OHS (p=0.665) or UCLA (p=0.831) between patients with or without elevated blood metal ions.

5 years after the insertion of MoP THAs, we found no differences in the blood metal ion levels between 32 mm heads and 36–44 mm heads and no corrosion-related revisions. As taper corrosion can debut after 5 years, there is still a need for long-term follow-up studies on the association between head size and corrosion in MoP THA.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 80 - 80
23 Jun 2023
Halken CH Jensen CB Henkel C Gromov K Troelsen A
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The interest in day-case hip arthroplasty is increasing; however, there are conflicting results regarding readmission risk, and little is known about patients’ attitude towards day-case surgery. We aimed to investigate differences in 30-day readmission rates between day-case patients and single-overnight-stay patients following total hip arthroplasty (THA) and explore patients’ attitude towards day-case surgery.

From the Danish National Patient Register we identified 29,486 THAs (1353 day-case THAs and 28,133 single-overnight-stay THAs) performed between 2010 and 2020. Day-case surgery was defined as discharge on the day-of-surgery. Overnight admissions within 30 days of surgery were considered readmissions. Differences in readmission rates between day-case and single-overnight-stay patients were investigated using logistic regression adjusted for patient characteristics and year of surgery. In a single-center descriptive study, 2395 hip arthroplasty patients from 2016 to start-2023 answered a questionnaire on patient characteristics, attitude towards day-case surgery and patient-reported outcome measures (PROM).

The overall 30-day readmission rate was 4.4% (CI: 4.2–4.6%) with no difference between day-case (4.4%) and single-overnight-stay THAs (4.4%) (odds-ratio: 1.2 [CI: 0.91–1.6]). In the descriptive study answers to the question whether patients were interested in being discharged on the day of surgery, were: “Yes” = 41%, “Do not know” = 20%, “No” = 39%. Patients responding “No” had lower preoperative PROM-scores, were older (“No” = 70.2 y vs. “Yes” = 65.3 y), and more often female (“No” = 72% vs. “Yes” = 52% female).

Based on nationwide data from 2010–2020, day-case THA patients were not more likely to be readmitted compared to single-overnight-stay patients. However, most patients were not positive towards day-case surgery. While surgeons may consider day-case surgery to be safe, patients are not intuitively positive, indicating an attitude mismatch. To achieve high success rate and patient satisfaction in day-case surgery, shared-decision making initiatives within day-case surgery are needed.


The Bone & Joint Journal
Vol. 103-B, Issue 7 | Pages 1206 - 1214
1 Jul 2021
Tsikandylakis G Mortensen KRL Gromov K Mohaddes M Malchau H Troelsen A

Aims

We aimed to investigate if the use of the largest possible cobalt-chromium head articulating with polyethylene acetabular inserts would increase the in vivo wear rate in total hip arthroplasty.

Methods

In a single-blinded randomized controlled trial, 96 patients (43 females), at a median age of 63 years (interquartile range (IQR) 57 to 69), were allocated to receive either the largest possible modular femoral head (36 mm to 44 mm) in the thinnest possible insert or a standard 32 mm head. All patients received a vitamin E-doped cross-linked polyethylene insert and a cobalt-chromium head. The primary outcome was proximal head penetration measured with radiostereometric analysis (RSA) at two years. Secondary outcomes were volumetric wear, periacetabular radiolucencies, and patient-reported outcomes.


The Bone & Joint Journal
Vol. 99-B, Issue 4 | Pages 451 - 457
1 Apr 2017
Gromov K Bersang A Nielsen CS Kallemose T Husted H Troelsen A

Aims

The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana).

Patients and Methods

A total of 1598 consecutive hips, in 1441 patients receiving primary THA between January 2010 and June 2015, were retrospectively identified. Level of pre-operative osteoarthritis, femoral Dorr type and cortical index were recorded. Varus/valgus placement of the stem and canal fill ratio were recorded post-operatively. Periprosthetic fractures were identified and classified according to the Vancouver classification. Regression analysis was performed to identify risk factors for early periprosthetic fracture.