The addition of a rougher surface finish to a modular stem may have contributed to high levels of osteolysis and stem failure, according to study results.
Researchers prospectively followed 105 patients who underwent 112 total hip arthroplasties using a Spectron EF stem (Smith & Nephew) between March 1997 and July 2000. Overall, 19.6% of the original cohort was revised at latest follow-up.
The researchers obtained radiological follow-up in 99% and clinical follow-up in all of the surviving 91 hips at a minimum of 10 years postoperatively.
Study results showed a rise in Harris Hip Scores from 48 preoperatively to 70 at latest follow-up. The researchers also found osteolytic lesions in 54% of femoral stems in at least one zone at either latest follow-up or at the time of revision.
Although the presence of osteolysis was significantly associated with the degree of cup wear, it was not associated with type of cup use or minimum cement thickness in zones 1 or 7, according to the researchers.
Study results showed aseptic revision or radiological failure of the stem was significantly associated with age, Dorr ratio, initial Barrack grading, any change in stem alignment, cement fracture, cortical hypertrophy, wear and osteolysis.
Survivorship at 11 years was 0.783, with the endpoint being revision of the stem for aseptic loosening or radiological failure of the stem. Additionally, the researchers found a significantly higher aseptic failure among patients 50 years or younger and a significant difference in the survival curves between patients younger and older than 50 years.
Disclosures: Burston was on the speakers’ bureau for Zimmer and DePuy. Wood received financial or material support from Smith & Nephew.