Publications (2)7.21 Total impact
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Article: Medial collateral ligament injuries and subsequent load on the anterior cruciate ligament: a biomechanical evaluation in a cadaveric model.
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ABSTRACT: Numerous studies have documented the effect of complete medial collateral ligament injury on anterior cruciate ligament loads; few have addressed how partial medial collateral ligament disruption affects knee kinematics. To determine knee kinematics and subsequent change in anterior cruciate ligament load in a partial and complete medial collateral ligament injury model. Controlled laboratory study. Ten human cadaveric knees were sequentially tested by a robot with the medial collateral ligament intact, in a partial injury model, and in a complete injury model with a universal force-moment sensor measuring system. Tibial translation, rotation, and anterior cruciate ligament load were measured under 3 conditions: anterior load (125 N), valgus load (10 N x m), and internal-external rotation torque (4 N x m; all at 0 degrees and 30 degrees of flexion). Anterior and posterior translation did not statistically increase with a partial or complete medial collateral ligament injury at 0 degrees and 30 degrees of flexion. In response to a 125 N anterior load, at 0 degrees , the anterior cruciate ligament load increased 8.7% (from 99.5 to 108.2 N; P = .006) in the partial injury and 18.3% (117.7 N; P < .001) in the complete injury; at 30 degrees , anterior cruciate ligament load was increased 12.3% (from 101.7 to 114.2 N; P = .001) in the partial injury and 20.6% (122.7 N; P < .001) in the complete injury. In response to valgus torque (10 N x m) at 30 degrees , anterior cruciate ligament load was increased 55.3% (30.4 to 47.2 N; P = .044) in the partial injury model and 185% (86.8 N; P = .001) in the complete injury model. In response to internal rotation torque (4 N.m) at 30 degrees , anterior cruciate ligament load was increased 29.3% (27.6 to 35.7 N; P = .001) in the partial injury model and 65.2% (45.6 N; P < .001) in the complete injury model. The amount of internal rotation at 30 degrees of flexion was significantly increased in the complete injury model (22.8 degrees ) versus the intact state (19.5 degrees ; P < .001). Partial and complete medial collateral ligament tears significantly increased the load on the anterior cruciate ligament. In a partial tear, the resultant load on the anterior cruciate ligament was increased at 30 degrees of flexion and with valgus load and internal rotation torque. Patients may need to be protected from valgus and internal rotation forces after anterior cruciate ligament reconstruction in the setting of a concomitant partial medial collateral ligament tear. This information may help clinicians understand the importance of partial injuries of the medial collateral ligament with a combined anterior cruciate ligament injury complex.The American journal of sports medicine 12/2008; 37(2):305-11. · 3.61 Impact Factor -
Article: Results of revision anterior cruciate ligament surgery.
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ABSTRACT: Revision anterior cruciate ligament surgery remains challenging. To analyze the authors' experience with revision anterior cruciate ligament surgery and determine the association between stability and functional results. Case series; Level of evidence, 4. Between 1991 and 2002, 95 of 102 patients who underwent revision anterior cruciate ligament reconstruction at the authors' institution met the criteria for inclusion in the study. Of those, the 63 (66%) who returned for complete clinical and radiologic evaluation (mean follow-up, 72.7 months) formed the study group. Subjective evaluation focused on return to sports, arthritic symptoms, and subjective International Knee Documentation Committee criteria. Clinical evaluation included examination, KT-1000 arthrometer and functional testing, and radiographic analysis of alignment and arthritis. Based on International Knee Documentation Committee subjective scores and return to sports, results were rated as excellent/good in 45 patients (71%), fair in 6 (10%), and poor in 12 (19%). A grade IA or IIA Lachman and a KT-1000 arthrometer side-to-side difference of <3 mm (32/63 patients) was associated with a good/excellent result (P < .05). The mechanical axis was midline in 78% (49/63 patients). Radiographic arthritis (16 patients, 25%) was associated with duration of instability after primary failure (P < .03). Return to sports occurred in 59% (37/63 patients). Sixteen patients (25%) required a second revision surgery. Revision anterior cruciate ligament surgery allowed approximately 60% of patients to go back to sports, most of them at lower levels than their prerevision function. Instrumented laxity of <3 mm was associated with a better result. Radiographic arthritis was associated with duration of instability symptoms after primary failure. Patients who undergo revision anterior cruciate ligament surgery should be counseled as to the expected outcome and cautioned that this procedure probably represents a salvage situation and may not allow them to return to their desired levels of function.The American journal of sports medicine 12/2007; 35(12):2057-66. · 3.61 Impact Factor
Top Journals
Institutions
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2008
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United States Naval Academy
Annapolis, MD, USA
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2007
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Weill Cornell Medical College
New York City, NY, USA
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