Cementless modular neck stems: are they a safe option in primary total hip arthroplasty?

PURPOSE: The objective was to assess aseptic complications and functional outcome using a primary total hip arthroplasty with modular neck.

METHODS: Prospective cohort of 317 consecutive patients. The mean age was 61.1 (range, 41-84) years. The H-Max-M model (Lima, Italy) system was used in all patients. The functional assessment was made by the Harris Hip Score, Short Form-36 (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index and visual analogue scale for pain. Radiological outcomes were also assessed, and adverse events and complications were noted.

RESULTS: The mean follow-up was 6.1 (range, 2-8) years. Functional outcome significantly improved in most patients. There were 3 deep infections (0.9%) and 17 aseptic complications (5.3%) including 1 intraoperative acetabular fracture, 3 later periprosthetic femoral fractures, 1 broken ceramic insert, 1 acetabular loosening, 3 femoral loosening and 1 broken titanium modular neck in a obese patient. No pseudotumors or elevated serum levels of metal ions were found among the patients with radiolucent lines or aseptic loosening.

CONCLUSIONS: The findings in the present study showed that the H-MAX-M stem provided satisfactory functional outcome in most patients with a low rate of complications attributable to the modular neck design. We consider that using this novel modular neck-stem coupling design can be an alternative to the conventional monoblock stems in patients without overweight.