Injuries to the anterior cruciate ligament (ACL) are occurring at epidemic proportions especially those resulting from athletic endeavors. The most common surgical treatment for a disrupted ACL is in autogenous bone-patella tendon-bone reconstruction (RACL). The rehabilitation after a reconstruction remains an enigma because of the lack of information necessary to develop universally accepted techniques which are effective and safe. An arthroscopically assisted bone-patellar tendon-bone intra-articular reconstruction of the ACL will be performed utilizing standard graft placement, tensioning, and fixation techniques. At the completion of the reconstruction the investigators will arthroscopically insert into the RACL the Hall strain sensor. The RACL strain pattern will be measured during activities common to physical examination and prescribed rehabilitation programs. These data will be compared with data previously obtained in vivo from a group of patients with normal anterior cruciate ligaments, and demonstrate our ability to restore normal kinematics to the knee joint at the time of RACL implantation. In addition, this data will provide a basis for knee rehabilitation regimes by establishing the effect that variations in joint position, muscle contractions, and external load applied to the knee have on RACL strain. Following surgery a standardized moderately aggressive rehabilitation program will be used for all patients. All patients involved in the study will be asked to participate in an arthroscopic reevaluation approximately one year following the initial surgery. During this procedure the RACL will be instrumented with the Hall strain sensor. The test protocol used to evaluate RACL strain at the time of RACL implantation will be repeated. These data will then be compared to that collected at the time of the initial reconstruction. This will provide a quantitative analysis of any RACL changes during the first year of rehabilitation and identify any effect of healing time, and our rehabilitation program has on RACL strain. In these patients additional testing will be performed to measure the RACL strain pattern during the performance of several activities of daily living. These data will be compared with the data previously obtained in vivo from patients with normal anterior cruciate ligaments. These comparisons will demonstrate the ability of our rehabilitation program to restore normal kinematics to the knee joint one year post RACL implantation, and prove the safety or show any damaging effects of our rehabilitation protocol. These data are expected to be extremely useful to those involved in the evaluation, treatment and rehabilitation of ACL injuries by providing an objective characterization of ACL function. By using these experimental methods, others could prove the effectiveness of their own surgical procedures and rehabilitation techniques.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR040174-02
Application #
3160481
Study Section
Orthopedics and Musculoskeletal Study Section (ORTH)
Project Start
1990-03-01
Project End
1994-02-28
Budget Start
1991-03-01
Budget End
1992-02-29
Support Year
2
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Vermont & St Agric College
Department
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Fleming, Braden C (2003) Biomechanics of the anterior cruciate ligament. J Orthop Sports Phys Ther 33:A13-5
Fleming, B C; Peura, G D; Beynnon, B D (2000) Factors influencing the output of an implantable force transducer. J Biomech 33:889-93
Fleming, B C; Good, L; Peura, G D et al. (1999) Calibration and application of an intra-articular force transducer for the measurement of patellar tendon graft forces: an in situ evaluation. J Biomech Eng 121:393-8
Fleming, B C; Beynnon, B D; Renstrom, P A et al. (1998) The strain behavior of the anterior cruciate ligament during bicycling. An in vivo study. Am J Sports Med 26:109-18
Beynnon, B; Yu, J; Huston, D et al. (1996) A sagittal plane model of the knee and cruciate ligaments with application of a sensitivity analysis. J Biomech Eng 118:227-39
Tohyama, H; Beynnon, B D; Johnson, R J et al. (1996) The effect of anterior cruciate ligament graft elongation at the time of implantation on the biomechanical behavior of the graft and knee. Am J Sports Med 24:608-14
Beynnon, B D; Proffer, D; Drez Jr, D J et al. (1995) Biomechanical assessment of the healing response of the rabbit patellar tendon after removal of its central third. Am J Sports Med 23:452-7
Beynnon, B D; Johnson, R J; Fleming, B C et al. (1994) The measurement of elongation of anterior cruciate-ligament grafts in vivo. J Bone Joint Surg Am 76:520-31
Fleming, B C; Beynnon, B D; Nichols, C E et al. (1994) An in vivo comparison between intraoperative isometric measurement and local elongation of the graft after reconstruction of the anterior cruciate ligament. J Bone Joint Surg Am 76:511-9
Beynnon, B D; Johnson, R J; Toyama, H et al. (1994) The relationship between anterior-posterior knee laxity and the structural properties of the patellar tendon graft. A study in canines. Am J Sports Med 22:812-20

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