System behavior of cranial cruciate reconstruction autografts commonly used in the canine stifle : a thesis /
Biomechanical analysis was performed on the cranial cruciate ligament (CCL) and three autogenous tissues used for CCL reconstruction in the canine stifle. The autogenous tissues were those described for over-the-top intraarticular replacement and included autografts based upon the central one-third...
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| Format: | Thesis Book |
| Language: | English |
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College Station, TX :
Texas A&M University,
1989.
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| Summary: | Biomechanical analysis was performed on the cranial cruciate ligament (CCL) and three autogenous tissues used for CCL reconstruction in the canine stifle. The autogenous tissues were those described for over-the-top intraarticular replacement and included autografts based upon the central one-third of the patellar ligament (CPT), the medial one-third of the patellar ligament (MPT), and the lateral one-third of the patellar ligament with distal fascia lata (LPT-FL). Tension testing was performed to failure on each of the preparations at a constant rate of 25 mm per second. Distinctive modes of failure were seen for the autograft preparations. The CPT and MPT failed abruptly while the LPT-FL failed sequentially, sustaining load longer than the other autographs. The load and displacement data were analyzed to determine the structural properties for the overload condition and within the load range of normal activity for the CCL (physiologic range). For the overload condition, none of the autograft systems approached the stiffness, maximum load, and energy absorbed up to maximum load of the CCL. A comparison of the autografts showed a significantly greater maximum load, energy absorbed up to maximum load and stiffness for the CPT and LPT-FL autografts than the MPT. For the physiologic range, a load of 169 newtons (N) defined the lower limit of this range and stiffness up to that load was calculated. Similar values for stiffness of the autografts in the overload and physiologic conditions supported the premise that the overall structural stiffness is representative of graft stiffness under physiologic conditions. The upper limit of the physiologic range was considered to be 25% of the CCL maximum load which corresponded to the proportional limits of the CPT and LPT-FL. By defining the elastic range for the grafts by proportional limit, the CPT and LPT-FL were expected to function elastically within the physiologic range for the CCL. The average load at the proportional limit for the MPT was below the physiologic range and suggested that this graft may be in danger of permanent deformation during normal activity. Because the displacement of the CCL at maximum load (7.17 mm) was beyond what the secondary joint restraints would theoretically allow, a physiologic displacement of 4 mm was used and a corresponding load response was determined for each preparation. The load responses of the CPT and LPT-FL were at or near the maximum load of the fixation site for early repairs (169 N). This underscored the need for postoperative support of the repaired stifle, not only to protect the grafts but to protect the fixation site. |
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| Item Description: | Typescript (photocopy). "Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of Master of Science August 1989". "Major Subject: Veterinary Medicine and Surgery". Approved as to style and content by: Donald A. Hulse, Harry A. Hogan, Harry W. Boothe, James K. Nelson, John R. August Vita. |
| Physical Description: | x, 40 leaves : photographs, charts ; 29 cm. |
| Bibliography: | Includes bibliographical references (leaves 32-35). |