Early-term clinical and radiographic outcomes of a new short cementless stem for primary total hip arthroplasty in young and active patients.

PURPOSE: To evaluate implant survivorship, complication rates and clinical and radiographic outcomes of a novel cementless short femoral stem used in primary total hip arthroplasty (THA).

METHODS

This monocentric retrospective study included 200 consecutive patients younger than 65 years undergoing primary unilateral THA with a cementless short femoral stem and a minimum follow-up of 2 years. All procedures were performed by a single fellowship-trained surgeon using a posterolateral approach. Clinical outcomes were assessed using the modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Visual Analogue Scale (VAS). Radiographic analysis included stem alignment, subsidence, fixation, stress shielding, radiolucent lines (RLLs), cortical hypertrophy and heterotopic ossification. Implant survivorship was estimated using Kaplan-Meier analysis, with revision for any cause as the endpoint.

RESULTS

At a mean follow-up of 36.2 months (range: 24.0-44.0), stem survivorship was 100.0%, with no femoral components revised. One patient (0.5%) underwent head exchange for instability. Complication and reoperation rates were 1.5% and 1.0%, respectively. No femoral fractures, subsidence or aseptic loosening were observed. All clinical scores improved significantly: mHHS increased from 67.6 to 97.8, WOMAC from 60.5 to 1.5 and VAS from 7.6 to 0.3 (p < 0.0001). Return to sport was achieved in 85.0% of patients. Radiographically, 11.0% of stems were in varus and 5.0% in valgus. RLLs <2 mm occurred in 23.0% of cases without loosening. Stress shielding was limited (Grade I-II in 15.0%), cortical hypertrophy occurred in 4.0% and spot welds in 32.0% of patients.

CONCLUSION

This short femoral stem demonstrated excellent early survivorship with reliable metaphyseal fixation and low complication rates, supporting its use as a safe bone-preserving option in young and active patients.

LEVEL OF EVIDENCE: Level IV.