Are titanium-on-titanium TiAl6V4 modular necks safe in total hip arthroplasty for non-overweight patients? Results of a prospective series at a minimum follow-up of 7 years.

Using extramedullar modularity in total hip arthroplasty has been proposed as an option to optimize the restoration of hip biomechanics. To avoid the problems that were observed with cobalt-chrome modular neck, titanium modular necks have been developed. The goals of our study were to evaluate the safety of titanium-on-titanium TiAl6V4 modular neck system. Hundred patients with a mean age of 69.6 ± 10.6 (42-86 years) and mean BMI of 25.07 ± 4.86 (17-38 kg/m(2)) suffering from primary or secondary arthritis of the hip were prospectively included. At a minimum of 7 years, no fracture of the modular neck was observed. No patient required a revision. No sign of loosening was found in the radiological analysis. Our study shows that titanium-on-titanium TiAl6V4 modular neck system can safely be used with good midterm clinical and radiological results for non-overweight patients. These results should be confirmed at longer follow-up.