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Soft tissue restricts impingement-free mobility in total hip arthroplasty
Michael Woerner1, Markus Weber2, Ernst Sendtner2
1Department of Orthopaedic Surgery, Regensburg University Medical Center, Asklepios Klinikum Bad Abbach, Kaiser-Karl V.-Allee 3, 93077, Bad Abbach, Germany. m.woerner@asklepios.com.
International Orthopaedics
|May 7, 2016
Summary
Soft tissue impingement significantly reduces range of motion (ROM) after total hip arthroplasty (THA) more than bony or prosthetic issues. Future THA planning should account for soft tissue restrictions to improve patient outcomes.
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
- Biomechanics
Background:
- Impingement is a primary cause of reduced range of motion (ROM) and dislocation in total hip arthroplasty (THA).
- Distinguishing between soft tissue and bony/prosthetic impingement is crucial for understanding ROM limitations.
Purpose of the Study:
- To analyze the impact of soft tissue impingement on ROM in THA patients.
- To compare the effects of soft tissue impingement versus bony and/or prosthetic impingement on ROM.
Main Methods:
- Prospective clinical trial involving 54 patients undergoing cementless THA with imageless navigation.
- Intra-operative ROM measurements using navigation to detect soft tissue impingement.
- Postoperative 3D-CT scans and collision-detection algorithms to calculate absolute ROM without bony/prosthetic impingement.
Main Results:
- Soft tissue impingement caused a significant ROM reduction (>20° for flexion, extension, abduction, adduction; >10° for external rotation) compared to bony/prosthetic impingement (p<0.001).
- Soft tissue impingement had minimal impact on internal rotation at 90° flexion (p=0.76).
- Multivariate analysis indicated BMI is associated with flexion ROM, but not other ROM directions.
Conclusions:
- Soft tissue impingement substantially impacts impingement-free ROM after THA, exceeding the limitations imposed by bony or prosthetic factors for most movements.
- Future patient-specific joint replacement models should incorporate pre-operative planning and intra-operative navigation that accounts for soft tissue impingement.
