Related Experiment Videos
Total hip arthroplasty. Concerns with extensively porous coated femoral components
J P McAuley1, W J Culpepper, C A Engh
1Anderson Orthopaedic Research Institute, Alexandria, VA 22306, USA.
Insights
This study found extensively coated cementless femoral components in hip arthroplasty demonstrate clinical success. Concerns regarding reoperation, thigh pain, and instability were not supported by the 5-year follow-up data.
Area of Science:
- Orthopedic Surgery
- Biomaterials Engineering
- Medical Device Research
Background:
- Cementless hip arthroplasty utilizes extensively coated femoral components to promote bone ingrowth.
- Potential concerns include reoperation rates, thigh pain, component stability, osteolysis, and stress shielding.
Purpose of the Study:
- To evaluate the clinical and radiographic outcomes of extensively coated cementless femoral components in hip arthroplasty.
- To specifically assess reoperation frequency, thigh pain, component stability, osteolysis, and stress shielding.
Main Methods:
- Review of 507 consecutive cementless hip arthroplasties performed by a single surgeon.
- Minimum 5-year follow-up for 426 hips, excluding those lost to follow-up or deceased.
- Radiographic and clinical assessment of component fixation, bone ingrowth, osteolysis, and thigh pain.
Main Results:
- Overall femoral reoperation rate was 2.6% (7 for fixation failure, 6 for osteolysis).
- 96% of unrevised components showed radiographic bone ingrowth; 3.7% had stable fibrous fixation.
- Activity-limiting thigh pain occurred in 2.9% of cases without identifiable predisposing factors.
- Osteolysis was detected in 11.7% of cases, primarily in Gruen Zones 1 and 7, with circumferential coating showing protective effects.
- Stress shielding was observed in 25% of cases, linked to older patients and larger stem diameters, but did not impact clinical outcomes or component stability.
Conclusions:
- Extensively coated cementless femoral components demonstrate clinical and radiographic success in hip arthroplasty.
- Concerns regarding high reoperation rates, thigh pain, component instability, and stress shielding are not substantiated by this study's findings.
- While debris generation and osteolysis remain considerations, the design appears safe and effective for long-term hip arthroplasty outcomes.
Abstract:
A series of 507 consecutive, unselected cementless hip arthroplasties performed by one surgeon was reviewed to address specifically potential concerns with the use of extensively coated femoral components, including the frequency and nature of reoperation, thigh pain, component stability, osteolysis, and stress shielding. Excluding hips in patients who had died or were lost to followup, there were 426 hips with minimum 5-year followup. The overall femoral reoperation rate of 2.6% (13 cases) included seven for failure of fixation and six for osteolysis. Of the unrevised cases, 96% of the femoral components showed radiographic bone ingrowth, and 3.7% showed a stable fibrous pattern. Fixation did not deteriorate with time. A 2.9% incidence of activity limiting thigh pain did affect clinical outcome (limp, ambulation tolerance, support), but there were no clinical or radiographic predisposing variables. There was no detectable femoral osteolysis in 88.3% of cases. The remainder had lesions confined to Gruen Zones 1 and 7, suggesting that circumferential extensive coating was protective against distal osteolysis. Although osteolysis did not affect component stability, in six cases it did result in pathologic trochanteric fracture, contributing to the frequency of reoperation. Stress shielding was common (25%) and was related to older patients and the use of larger diameter stems (> 15 mm), but did not predispose to thigh pain, loosening, osteolysis, or an inferior clinical result. These results documented the clinical and radiographic success in the use of extensively coated cementless femoral components. Debris generation from wear and resulting osteolysis remain significant concerns in a hip arthroplasty with this design as with many others. However, concerns about the high incidence of reoperation, thigh pain, component instability, or stress shielding are not supported by this study.