OBJECTIVES: Comparison of one-plane and two-plane external fixation in terms of successful healing, incidence of complications, and biomechanical stability in a sheep model. BACKGROUND: Rigid fixation is preferred in open and comminuted fractures with a reduced blood supply, preventing infection and healing delay, but more often a flexible device is recommended even in unfavourable healing conditions. METHODS: The left tibiae of fifteen sheep were osteotomized and laterally fixed with a four-screw unilateral fixator frame (axial stiffness 183 N/mm) to a 3 mm gap size. In 9 of 15 sheep, an additional four-screw unilateral external fixator was anterolaterally attached (total axial stiffness of both frames 388 N/mm). After sacrificing, quality of osteotomy healing was assessed by mechanical and radiological evaluations. Osteogenesis was measured using fluorescence microscopy. RESULTS: Two distal fractures through the pin-tracks, three non-unions and four deep infections occurred after two-plane fixation. These failures excluded, osteotomy healing showed inferior results after two-plane fixation with reduced callus formation, bone mineral content, and bending stiffness amounts, respectively. Osteogenesis was halved following two-plane fixation in the remaining sheep. CONCLUSIONS: Two-plane fixation was not sufficient to reach successful osteotomy healing in our study. While higher rigidity was expected to prevent complications, healing in this group might have been disturbed by a reduced blood supply. The optimal stabilisation for a given fracture depends on many factors, including the biomechanical and biological environment. RELEVANCE: Considering our results and the literature discussed in this manuscript, good bone healing with minor risks of infections can be achieved using an unilateral one-plane fixator with only four screws, and its application on a muscle free position like the medial and anterior site of the sheep tibia.
OBJECTIVES: Comparison of one-plane and two-plane external fixation in terms of successful healing, incidence of complications, and biomechanical stability in a sheep model. BACKGROUND: Rigid fixation is preferred in open and comminuted fractures with a reduced blood supply, preventing infection and healing delay, but more often a flexible device is recommended even in unfavourable healing conditions. METHODS: The left tibiae of fifteen sheep were osteotomized and laterally fixed with a four-screw unilateral fixator frame (axial stiffness 183 N/mm) to a 3 mm gap size. In 9 of 15 sheep, an additional four-screw unilateral external fixator was anterolaterally attached (total axial stiffness of both frames 388 N/mm). After sacrificing, quality of osteotomy healing was assessed by mechanical and radiological evaluations. Osteogenesis was measured using fluorescence microscopy. RESULTS: Two distal fractures through the pin-tracks, three non-unions and four deep infections occurred after two-plane fixation. These failures excluded, osteotomy healing showed inferior results after two-plane fixation with reduced callus formation, bone mineral content, and bending stiffness amounts, respectively. Osteogenesis was halved following two-plane fixation in the remaining sheep. CONCLUSIONS: Two-plane fixation was not sufficient to reach successful osteotomy healing in our study. While higher rigidity was expected to prevent complications, healing in this group might have been disturbed by a reduced blood supply. The optimal stabilisation for a given fracture depends on many factors, including the biomechanical and biological environment. RELEVANCE: Considering our results and the literature discussed in this manuscript, good bone healing with minor risks of infections can be achieved using an unilateral one-plane fixator with only four screws, and its application on a muscle free position like the medial and anterior site of the sheep tibia.
Authors: Joachim A Hahn; Tanja S Witte; Daniel Arens; Alexandra Pearce; Simon Pearce Journal: BMC Musculoskelet Disord Date: 2011-09-29 Impact factor: 2.362
Authors: Muhammad Hanif Ramlee; Mohd Ayub Sulong; Evelyn Garcia-Nieto; Daniel Angure Penaranda; Antonio Ros Felip; Mohammed Rafiq Abdul Kadir Journal: Med Biol Eng Comput Date: 2018-04-21 Impact factor: 2.602