Journal article
Hinged external fixation of the knee: Intrinsic factors influencing passive joint motion
Journal of orthopaedic trauma, Vol.18(3), pp.163-169
2004
DOI: 10.1097/00005131-200403000-00007
PMID: 15091271
Abstract
Objective: To measure changes in knee kinematics after the application of articulated external fixators along a previously described knee flexion/extension axis and 16 specific "off-axis" fixator hinge configurations.
Design: Cadaver, biomechanical study.
Setting: Biomechanics laboratory.
Participants: Nine fresh cadaver knee specimens.
Intervention: Each specimen was mounted on a custom-built frame that constrained the knee to move about a fixed flexion/extension axis. Passive knee motion was induced, and the resulting flexion moment was measured. Data were collected for the on-axis fixator position and 16 distinct rotational and translational off-axis positions. In addition, effects of tibial translation and rotation were investigated.
Main outcome: Range of motion (ROM) attainable within a moment envelope of +/-1 N-m and average energy required to impart movement.
Results: The average ROM for unconstrained knees was 122 degree. Constraining the knee to rotation around an on-axis aligned hinge significantly reduced the ROM by 35% to 79 degree. The 5-mm posterior translated hinge was the only alignment to show on average a slightly larger ROM (86 degree) than the on-axis hinge. All other hinge alignments showed decreased average ROM compared with the on-axis position. Tibiofemoral alignments significantly affected the obtainable ROM for the on-axis aligned hinge.
Conclusion: It was not possible to replicate precisely the complex kinematics of the knee using a single axis fixator over the entire ROM. Using the axis of rotation previously defined in the literature, however, it was possible to obtain a limited ROM of the knee without placing excessive forces on the periarticular structures.
Details
- Title: Subtitle
- Hinged external fixation of the knee: Intrinsic factors influencing passive joint motion
- Creators
- Mark B SOMMERS - Biomechanics Laboratory, Legacy Clinical Research & Technology Center, Portland, OR, United StatesDaniel C FITZPATRICK - Orthopedic Healthcare Northwest, Eugene, OR, United StatesKevin M KAHN - Oregon Health & Science University, Portland, OR, United StatesJ. Lawrence MARSH - University of Iowa, Hospitals and Clinics, Iowa City, IA, United StatesMichael BOTTLANG - Biomechanics Laboratory, Legacy Clinical Research & Technology Center, Portland, OR, United States
- Resource Type
- Journal article
- Publication Details
- Journal of orthopaedic trauma, Vol.18(3), pp.163-169
- Publisher
- Lippincott Williams & Wilkins; Hagerstown, MD
- DOI
- 10.1097/00005131-200403000-00007
- PMID
- 15091271
- ISSN
- 0890-5339
- eISSN
- 1531-2291
- Language
- English
- Date published
- 2004
- Academic Unit
- Orthopedics and Rehabilitation
- Record Identifier
- 9984040447602771
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