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Paper # 205: What is the Meaning of Curvature of Posterior Cruciate Ligament in Respect of Isometry
ABSTRACTS tion, 3 patients (12.5%) were graded normal, 15 patients (62.5%) nearly normal, and 6 patient (25%) abnormal. Conclusion: Simultaneous ACL/PCL/PMC/PLC reconstructions with autograft can get 12.5% normal and 62.5% nearly normal results at a minimum of two years. Level of evidence: ?, therapeutic case series.. Paper # 204: Is there an Increase in Posterior Laxity after PCL Reconstruction Over Time? A Serial Follow-Up with Stress Radiographs TOBIAS MAXIMILIAN JUNG, MD, GERMANY ANNA WIENAND, MD, GERMANY NORBERT HAAS, GERMANY ANDREAS WEILER, MD, PHD, GERMANY · Charité, Berlin, GERMANY Summary: Based on our study it appears that a successful PCL reconstruction is stretching out around 2 mm during the first year after surgery, concurrently we found a continuous improvement of the IKDC-score, indicating that despite a residual laxity good results could be accomplished. Abstract: Introduction: Today, knee stability after PCL reconstruction can hardly be restored as compared to ACL reconstruction. Thus, some authors suggest a successful PCL reconstruction if the preop. laxity is reduced to 50 % or more after surgery. However, it remains unclear whether this is due to an immediate postop. laxity increase or a subsequent posterior stretch-out during rehabilitation (to regain full flexion). We therefore, determined the postoperative posterior stretch-out after PCL reconstruction between the early an late rehabilitation phases. Methods: A prospective data base of 234 PCL reconstructions with either isolated or combined procedures was analysed. Patients were followed for a mean of 64 months (range: 38 – 114 months) using stress radiography and the IKDC score. Patients were followed prospectively (3, 6, 12, & 24 months after surgery) using the IKDC and Lysholm score. We determined the changes in posterior laxity over time by using posterior stress radiographs in 90° of knee flexion (Telos). Group 1: 154 patients with at least two postop. FU time points until 2 years Group 2: 53 patients with a complete FU until one year Group 3: 42 patients with a complete FU until one year and reduction of preoperative laxity ⬎ 50 % after 3 months (excluded failures)
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For comparison of mean displacement values we used a repeated-measure analysis of variance (ANOVA); level of significance was p ⬍ 0.05. Results: All groups showed a significant reduction in the postoperative posterior displacement (Tab. in mm). Overall IKDC results showed a significant continuous improvement over time, despite an increasing laxity of 1.7 to 2.3 mm between 3 months and 1 to 2 years, indicating an overall posterior stretch-out of approx. 2 mm. Group 1: preoperative SDS ⫽ 14.3 mm; 3 months postoperative SDS ⫽ 6.6 mm; 2 years postoperative SDS ⫽ 8.9 mm, indicating a stretch out of 2.3 mm. Group 2: preoperative SDS ⫽ 13.6 mm; 3 months postoperative SDS ⫽ 5.5 mm; 2 years postoperative SDS ⫽ 7.2 mm, indicating a stretch out of 1.7 mm. Group 3: preoperative SDS ⫽ 13.9 mm; 3 months postoperative SDS ⫽ 4 mm; 2 years postoperative SDS ⫽ 6.1 mm, indicating a stretch out of 2.1 mm. Conclusion: The results of this study show a significant increase of approximately 2 mm in the posterior displacement after PCL reconstruction between the early and late rehabilitation phases. This increase during the early period could be explained by the ongoing graftremodeling in combination with the relevant forces loading the graft. Furthermore, it is well known, that after PCL-reconstruction an increasing tightness of the posterior capsule can be found. During the later time period (12 – 24 moths after surgery) graft-elongation and / or graft-abrasion could be a reason for increasing posterior translation. However, we found a continuous improvement of the IKDC-score, indicating that despite a residual laxity good results could be accomplished.
Paper # 205: What is the Meaning of Curvature of Posterior Cruciate Ligament in Respect of Isometry HO-JOONG JUNG, MD, KOREA SANG HAK LEE, MD, SOUTH KOREA YOUNG BOK JUNG, MD, PHD, KOREA JIN HONG KIM, MD, SOUTH KOREA HAN-JUN LEE, MD, SOUTH KOREA JAE SUNG LEE, MD, SOUTH KOREA · Chung-Ang University, Seoul, SOUTH KOREA Summary: The vertical femoral tunnel with lateral tibial tunnel and graft passing over the remnant PCL have some benefit in respect to isometry in posterior cruciate ligament reconstruction.
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ABSTRACTS
Abstract: Introduction: In posterior cruciate ligament (PCL) reconstruction, there were some debates on tunnel position especially in femoral side. In addition, it has been known to have different features with ACL, in term of biomechanics, associated with unique curved course. The purpose of this study was to evaluate the isometry according to the different tunnel positions using 3-dimensional computed tomography (CT) scans compare with real isometric measurement. Methods: For the ten fresh cadaveric knees, tibial tunnels were marked at 2 different locations: (1) 6 mm proximal of posterior bony ridge on just medial side of PCL fiber, (2) 6 mm proximal of posterior bony ridge on just lateral side of PCL fiber. Femoral tunnel position was marked at 3 different locations: (1) 5 mm medial from vertical line and 5 mm proximal from articular margin, (2) 10 o’clock position and 5 mm proximal from articular margin, (3)10 o’clock position and 8 mm proximal from articular margin. All specimen were scanned by computed tomography, at 0°, 30°, 60°, 90°, and full of flexion and the length change between the tunnels were calculated using medical imaging software (OsiriX version 3.2). To compare with data from isometer, lateral tibial tunnel and 2 femoral tunnel (vertical and 10 o’clock) isometry was checked using isometer with No.5 Ethibond suture. For each test, isometry was checked by the suture passed over the PCL and under the PCL. Results: In all data checked by CT scan, from 0° to 60° knee flexion, lengths between tunnels were abruptly increased. In femoral tunnel, the closer to knee flexion arc center, showed the less increase in length (mid, vertical, 10 o’clock, respectively). In tibial tunnel, lateral tunnel showed the less excursion than medial tibial tunnel. The isometry measured by isometer with suture showed no statistically correlation with those of CT scan (p⬎0.05). Especially when the suture was passed over the PCL, mean excursion was significantly less than the under the PCL group (1.5 mm vs. 3.9 mm respectively). Conclusions: Isometry measured with CT scan showed different pattern with real isometer measurement. It might be caused by length compensation which made by conversion of curved PCL to straight from 0° to 60° knee flexion. Because the passing over the PCL could simulate the curved PCL course, it could reduce the graft excursion in near extension position. So, our results suggest that the vertical femoral tunnel with lateral tibial tunnel and graft passing over the remnant PCL have some benefit in respect to isometry in posterior cruciate ligament reconstruction.
Paper # 206: Evaluation of Clinical and Magnetic Resonance Imaging Results after Actively Managed Posterior Cruciate Ligament Injury SANG HAK LEE, MD, SOUTH KOREA JIN HWAN AHN, MD, SOUTH KOREA JOON HO WANG, MD, PHD, KOREA · Samsung Medical Center, Seoul, SOUTH KOREA Summary: In this study, our active, nonoperative method of casting and braces with attached tibial supporters, which was designed to prevent posterior displacement at the knee, yielded satisfactory functional and MRI results in the majority of patients at intermediate-term follow-up. Abstract: Background: No consensus has been reached on the ideal guideline for correlating physical examination findings, degree of instability, and magnetic resonance imaging (MRI) findings in patients with acute, isolated posterior cruciate ligament (PCL) tears. Hypotheses: 1) Nonoperative treatment for patients with acute, isolated PCL injuries would yield satisfactory clinical and MRI outcomes and 2) clinical and MRI results would be significantly correlated with the degree of posterior instability over time from the initial injury to follow-up evaluation. Study Design: Cases series; Level of evidence, 4. Methods: From February 2001 to January 2008, 49 consecutive patients with acute (⬍4 weeks), isolated PCL injuries underwent nonoperative treatment with cast immobilization and PCL braces. Of these patients, 38 who satisfied our inclusion criteria and could be followed for a minimum of 24 months (median, 51 months; range, 24 to 80 months) were enrolled in our study. Functional outcomes were evaluated at follow-up using the Lysholm knee scoring system, the Hospital for Special Surgery (HSS) knee scoring system and International Knee Documentation Committee (IKDC) subjective and objective knee scoring. Objective assessment consisted of physical examination and KT-1000 arthrometer at initial evaluation and follow-up. PCL injury status on MRI was assessed using a different scale for initial and follow-up MRI. Results: The grade of posterior instability was significantly improved from initial grades of 1 in 13 patients (34%) and 2 in 25 patients (66%) to follow-up grades of 0 in 3 patients (8%), 1 in 21 patients (55%) and 3 in 14 patients (37%) (P⫽0.006656). The mean side-to-side difference in posterior translation measured with KT1000 arthrometer was initially 6.7 (range, 4-10) mm and
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For comparison of mean displacement values we used a repeated-measure analysis of variance (ANOVA); level of significance was p ⬍ 0.05. Results: All groups showed a significant reduction in the postoperative posterior displacement (Tab. in mm). Overall IKDC results showed a significant continuous improvement over time, despite an increasing laxity of 1.7 to 2.3 mm between 3 months and 1 to 2 years, indicating an overall posterior stretch-out of approx. 2 mm. Group 1: preoperative SDS ⫽ 14.3 mm; 3 months postoperative SDS ⫽ 6.6 mm; 2 years postoperative SDS ⫽ 8.9 mm, indicating a stretch out of 2.3 mm. Group 2: preoperative SDS ⫽ 13.6 mm; 3 months postoperative SDS ⫽ 5.5 mm; 2 years postoperative SDS ⫽ 7.2 mm, indicating a stretch out of 1.7 mm. Group 3: preoperative SDS ⫽ 13.9 mm; 3 months postoperative SDS ⫽ 4 mm; 2 years postoperative SDS ⫽ 6.1 mm, indicating a stretch out of 2.1 mm. Conclusion: The results of this study show a significant increase of approximately 2 mm in the posterior displacement after PCL reconstruction between the early and late rehabilitation phases. This increase during the early period could be explained by the ongoing graftremodeling in combination with the relevant forces loading the graft. Furthermore, it is well known, that after PCL-reconstruction an increasing tightness of the posterior capsule can be found. During the later time period (12 – 24 moths after surgery) graft-elongation and / or graft-abrasion could be a reason for increasing posterior translation. However, we found a continuous improvement of the IKDC-score, indicating that despite a residual laxity good results could be accomplished.
Paper # 205: What is the Meaning of Curvature of Posterior Cruciate Ligament in Respect of Isometry HO-JOONG JUNG, MD, KOREA SANG HAK LEE, MD, SOUTH KOREA YOUNG BOK JUNG, MD, PHD, KOREA JIN HONG KIM, MD, SOUTH KOREA HAN-JUN LEE, MD, SOUTH KOREA JAE SUNG LEE, MD, SOUTH KOREA · Chung-Ang University, Seoul, SOUTH KOREA Summary: The vertical femoral tunnel with lateral tibial tunnel and graft passing over the remnant PCL have some benefit in respect to isometry in posterior cruciate ligament reconstruction.
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ABSTRACTS
Abstract: Introduction: In posterior cruciate ligament (PCL) reconstruction, there were some debates on tunnel position especially in femoral side. In addition, it has been known to have different features with ACL, in term of biomechanics, associated with unique curved course. The purpose of this study was to evaluate the isometry according to the different tunnel positions using 3-dimensional computed tomography (CT) scans compare with real isometric measurement. Methods: For the ten fresh cadaveric knees, tibial tunnels were marked at 2 different locations: (1) 6 mm proximal of posterior bony ridge on just medial side of PCL fiber, (2) 6 mm proximal of posterior bony ridge on just lateral side of PCL fiber. Femoral tunnel position was marked at 3 different locations: (1) 5 mm medial from vertical line and 5 mm proximal from articular margin, (2) 10 o’clock position and 5 mm proximal from articular margin, (3)10 o’clock position and 8 mm proximal from articular margin. All specimen were scanned by computed tomography, at 0°, 30°, 60°, 90°, and full of flexion and the length change between the tunnels were calculated using medical imaging software (OsiriX version 3.2). To compare with data from isometer, lateral tibial tunnel and 2 femoral tunnel (vertical and 10 o’clock) isometry was checked using isometer with No.5 Ethibond suture. For each test, isometry was checked by the suture passed over the PCL and under the PCL. Results: In all data checked by CT scan, from 0° to 60° knee flexion, lengths between tunnels were abruptly increased. In femoral tunnel, the closer to knee flexion arc center, showed the less increase in length (mid, vertical, 10 o’clock, respectively). In tibial tunnel, lateral tunnel showed the less excursion than medial tibial tunnel. The isometry measured by isometer with suture showed no statistically correlation with those of CT scan (p⬎0.05). Especially when the suture was passed over the PCL, mean excursion was significantly less than the under the PCL group (1.5 mm vs. 3.9 mm respectively). Conclusions: Isometry measured with CT scan showed different pattern with real isometer measurement. It might be caused by length compensation which made by conversion of curved PCL to straight from 0° to 60° knee flexion. Because the passing over the PCL could simulate the curved PCL course, it could reduce the graft excursion in near extension position. So, our results suggest that the vertical femoral tunnel with lateral tibial tunnel and graft passing over the remnant PCL have some benefit in respect to isometry in posterior cruciate ligament reconstruction.
Paper # 206: Evaluation of Clinical and Magnetic Resonance Imaging Results after Actively Managed Posterior Cruciate Ligament Injury SANG HAK LEE, MD, SOUTH KOREA JIN HWAN AHN, MD, SOUTH KOREA JOON HO WANG, MD, PHD, KOREA · Samsung Medical Center, Seoul, SOUTH KOREA Summary: In this study, our active, nonoperative method of casting and braces with attached tibial supporters, which was designed to prevent posterior displacement at the knee, yielded satisfactory functional and MRI results in the majority of patients at intermediate-term follow-up. Abstract: Background: No consensus has been reached on the ideal guideline for correlating physical examination findings, degree of instability, and magnetic resonance imaging (MRI) findings in patients with acute, isolated posterior cruciate ligament (PCL) tears. Hypotheses: 1) Nonoperative treatment for patients with acute, isolated PCL injuries would yield satisfactory clinical and MRI outcomes and 2) clinical and MRI results would be significantly correlated with the degree of posterior instability over time from the initial injury to follow-up evaluation. Study Design: Cases series; Level of evidence, 4. Methods: From February 2001 to January 2008, 49 consecutive patients with acute (⬍4 weeks), isolated PCL injuries underwent nonoperative treatment with cast immobilization and PCL braces. Of these patients, 38 who satisfied our inclusion criteria and could be followed for a minimum of 24 months (median, 51 months; range, 24 to 80 months) were enrolled in our study. Functional outcomes were evaluated at follow-up using the Lysholm knee scoring system, the Hospital for Special Surgery (HSS) knee scoring system and International Knee Documentation Committee (IKDC) subjective and objective knee scoring. Objective assessment consisted of physical examination and KT-1000 arthrometer at initial evaluation and follow-up. PCL injury status on MRI was assessed using a different scale for initial and follow-up MRI. Results: The grade of posterior instability was significantly improved from initial grades of 1 in 13 patients (34%) and 2 in 25 patients (66%) to follow-up grades of 0 in 3 patients (8%), 1 in 21 patients (55%) and 3 in 14 patients (37%) (P⫽0.006656). The mean side-to-side difference in posterior translation measured with KT1000 arthrometer was initially 6.7 (range, 4-10) mm and