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No medium-term advantage of electrochemical deposition of hydroxyapatite in cementless femoral stems. 5-year RSA and DXA results from a randomized controlled trial.

Flatøy B, Röhrl SM, Bøe B, Nordsletten L - Acta Orthop (2015)

Bottom Line: Bone resorption occurred mainly during the first year, and subsequently decreased to a rate close to what is seen in normal ageing.The greatest total decrease occurred in Gruen zones 1 and 7, similar in the groups at 5 years.Thus, at this point, Bonemaster appears to be safe.

View Article: PubMed Central - PubMed

Affiliation: a Department of Orthopedic Surgery , Oslo University Hospital Ullevål , Oslo , Norway .

ABSTRACT

Background and purpose: Hydroxyapatite has been used for a long time as an adjunct to enhance cementless fixation. The benefit of this is still debated, but new methods of hydroxyapatite deposition have emerged, offering possible gains. In order to investigate this further, we compared the migration pattern and periprosthetic bone remodeling in a cementless femoral stem with either electrochemically deposited hydroxyapatite-called Bonemaster (BM)-or a conventional plasma-sprayed hydroxyapatite (HA) coating.

Patients and methods: 55 hips were randomized to either BM or HA cementless femoral stems. Patients were followed with radiostereometry (RSA), dual-energy X-ray absorptiometry (DXA), radiographic measurements, and hip questionnaires for 5 years.

Results: For both stems, migration occurred mainly as subsidence and retroversion during the first 3 months. The BM group had a higher retroversion rate of 0.17° per month during this period, as compared to 0.06° per month for the HA group (p = 0.006). Thereafter, there was almost no movement in any direction for both stem types. Bone resorption occurred mainly during the first year, and subsequently decreased to a rate close to what is seen in normal ageing. The greatest total decrease occurred in Gruen zones 1 and 7, similar in the groups at 5 years. There was a slightly higher resorption rate in Gruen zone 7 from 2 to 5 years in the BM group (1.3% per year; p = 0.04), but in a magnitude that would scarcely affect stem stability or survival.

Interpretation: There were no clinically relevant differences between the 2 stems regarding stability or periprosthetic bone loss at 5 years. Electrochemically deposited HA does not appear to affect fixation or bone remodeling when compared to conventional plasma spraying at 5 years. Thus, at this point, Bonemaster appears to be safe.

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Related in: MedlinePlus

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Figure 0001: Consort flow chart.

Mentions: Standard radiographs were also performed up to 5 years, and evaluated for signs of instability and osseointegration (change in alignment, gross subsidence, calcar atrophy, periprosthetic radiolucency, pedestal formation, and trabecular remodeling). Periprosthetic radiolucent lines were defined as being >1 mm thick and spanning ≥50% of the Gruen zone. Harris hip score (HHS) and Oxford hip score (OHS) were used to evaluate clinical results. A single surgeon (BF) evaluated the radiographs. For further methodological issues, we refer the reader to the initial 2-year publication (Boe et al. 2011).


No medium-term advantage of electrochemical deposition of hydroxyapatite in cementless femoral stems. 5-year RSA and DXA results from a randomized controlled trial.

Flatøy B, Röhrl SM, Bøe B, Nordsletten L - Acta Orthop (2015)

Consort flow chart.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940590&req=5

Figure 0001: Consort flow chart.
Mentions: Standard radiographs were also performed up to 5 years, and evaluated for signs of instability and osseointegration (change in alignment, gross subsidence, calcar atrophy, periprosthetic radiolucency, pedestal formation, and trabecular remodeling). Periprosthetic radiolucent lines were defined as being >1 mm thick and spanning ≥50% of the Gruen zone. Harris hip score (HHS) and Oxford hip score (OHS) were used to evaluate clinical results. A single surgeon (BF) evaluated the radiographs. For further methodological issues, we refer the reader to the initial 2-year publication (Boe et al. 2011).

Bottom Line: Bone resorption occurred mainly during the first year, and subsequently decreased to a rate close to what is seen in normal ageing.The greatest total decrease occurred in Gruen zones 1 and 7, similar in the groups at 5 years.Thus, at this point, Bonemaster appears to be safe.

View Article: PubMed Central - PubMed

Affiliation: a Department of Orthopedic Surgery , Oslo University Hospital Ullevål , Oslo , Norway .

ABSTRACT

Background and purpose: Hydroxyapatite has been used for a long time as an adjunct to enhance cementless fixation. The benefit of this is still debated, but new methods of hydroxyapatite deposition have emerged, offering possible gains. In order to investigate this further, we compared the migration pattern and periprosthetic bone remodeling in a cementless femoral stem with either electrochemically deposited hydroxyapatite-called Bonemaster (BM)-or a conventional plasma-sprayed hydroxyapatite (HA) coating.

Patients and methods: 55 hips were randomized to either BM or HA cementless femoral stems. Patients were followed with radiostereometry (RSA), dual-energy X-ray absorptiometry (DXA), radiographic measurements, and hip questionnaires for 5 years.

Results: For both stems, migration occurred mainly as subsidence and retroversion during the first 3 months. The BM group had a higher retroversion rate of 0.17° per month during this period, as compared to 0.06° per month for the HA group (p = 0.006). Thereafter, there was almost no movement in any direction for both stem types. Bone resorption occurred mainly during the first year, and subsequently decreased to a rate close to what is seen in normal ageing. The greatest total decrease occurred in Gruen zones 1 and 7, similar in the groups at 5 years. There was a slightly higher resorption rate in Gruen zone 7 from 2 to 5 years in the BM group (1.3% per year; p = 0.04), but in a magnitude that would scarcely affect stem stability or survival.

Interpretation: There were no clinically relevant differences between the 2 stems regarding stability or periprosthetic bone loss at 5 years. Electrochemically deposited HA does not appear to affect fixation or bone remodeling when compared to conventional plasma spraying at 5 years. Thus, at this point, Bonemaster appears to be safe.

Show MeSH
Related in: MedlinePlus