In Vivo hip joint loading during cross-country skiing on a simulator

Area of Science:

• Orthopedic surgery
• Biomechanics
• Sports medicine

Background:

• Assessing return-to-sport capabilities after total hip arthroplasty (THA) is vital for active patients.
• Limited data exists on in vivo joint forces during athletic activities post-THA.
• Skiing's suitability after THA remains debated, necessitating direct measurement of joint loads.

Purpose of the Study:

• To measure in vivo joint forces and moments in instrumented total hip arthroplasty (THA) during simulated cross-country skiing.
• To compare these forces to those experienced during walking.

Main Methods:

• Five untrained subjects with instrumented THAs performed simulated double poling and diagonal poling.
• Walking on a treadmill served as a reference exercise.
• In vivo joint contact forces, bending moments, and torsion torques were quantified and analyzed using statistical parameter mapping.

Main Results:

• Most loading peaks during skiing were lower than or similar to walking, except during diagonal poling with foot lift.
• Execution variations in double poling influenced torsion torque patterns.
• Diagonal poling exhibited slightly higher bending moments compared to walking.

Conclusions:

• Double and diagonal poling appear safe for THA patients in the late postoperative phase, with joint loading often comparable to walking.
• Minimizing unilateral standing phases is recommended.
• Individual patient factors like experience and bone quality are critical for personalized recommendations.