James S. Starman

Primary Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction A Preliminary 2-Year Prospective Study

Background The anterior cruciate ligament consists of 2 functional bundles, the anteromedial bundle and the posterolateral bundle. Single-bundle anterior cruciate ligament reconstruction is the current standard for the treatment of anterior cruciate ligament deficiency. However, a significant subset of patients continues to report residual symptoms of instability after such reconstruction. Hypothesis Anatomic double-bundle anterior cruciate ligament reconstruction may more closely restore normal kinematics of the knee by reproducing the native anatomy. Study Design Case series; Level of evidence, 4. Methods We report the current clinical outcomes of the initial 100 consecutive patients who underwent anatomic double-bundle anterior cruciate ligament reconstruction with an average follow-up of 2.1 ± 0.5 years. All patients were prospectively followed to document range of motion, ligamentous laxity, and functional strength, as well as activity and sports participation. Results Side-to-side difference in range of motion was 2° ± 3° for extension and 2° ± 5° for flexion. Sixty-five percent of patients had a normal Lachman test result, and 33% were nearly normal. For the pivot-shift test findings, 94% were normal, and 6% were nearly normal. The average side-to-side difference in the KT-2000 arthrometer test was 1.0 ± 2.3 mm. There were 8 graft failures, 7 of which had subsequent revision surgery. No patients reported pain, swelling, or instability during activities of daily living, and 73% to 78% had no symptoms during very strenuous or strenuous sports activities. The scores of the International Knee Documentation Committee Subjective Knee Form, Activities of Daily Living, and Sports Activity Scores of the Knee Outcome Survey were 85.0, 91.8, and 87.0, respectively, and were similar compared with patients undergoing single-bundle anterior cruciate ligament reconstruction, which we have previously reported. Fifty-one percent described their current activity level as normal, and 35% reported it as nearly normal. Conclusion Anatomic double-bundle anterior cruciate ligament reconstruction results in good restoration of joint stability and patient-reported outcomes when evaluated 2 years after surgery.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

Abstract Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures performed by orthopaedic surgeons. The procedure has improved significantly since its inception in 1900 and continues to be intensively studied with outcomes receiving considerable attention. Traditional ACL reconstruction techniques have focused on one portion of the ACL—the anteromedial bundle. Single-bundle ACL reconstruction is the criterion standard and has provided good to excellent results, with many athletes being able to return to sports; however, recently, some authors have noted persistent instability with functional testing and degenerative radiographic changes after single-bundle ACL reconstruction. As a result, several centers have attempted to improve upon the single-bundle technique by reconstructing both the anteromedial and posterolateral bundles of the ACL. This article will present the embryologic, anatomic, and biomechanical rationale for double-bundle ACL reconstruction. In addition, the latest outcomes of double-bundle ACL reconstruction will be presented.

Anatomic, radiographic, biomechanical, and kinematic evaluation of the anterior cruciate ligament and its two functional bundles.

Outcomes following single-bundle anterior cruciate ligament reconstruction are generally good. However, a critical review of the literature shows that some patients have residual instability and pain following single-bundle anterior cruciate ligament reconstruction1-4. Recent clinical investigations have demonstrated that anteroposterior knee laxity, as measured with the KT-1000 and the Lachman test, is not associated with functional outcomes after anterior cruciate ligament reconstruction5. Conversely, there is a significant association between the pivot-shift test and functional outcomes after anterior cruciate ligament reconstruction (p = 0.03), which emphasizes the importance of rotational knee stability for functional recovery5. Biomechanical and kinematic studies have suggested that a more anatomical reconstruction of the anterior cruciate ligament may provide improved long-term outcomes. In this article, we describe the anatomy, radiographic characteristics, injury patterns, biomechanics, and kinematics of the anterior cruciate ligament. We also summarize the surgical technique and augmentation procedures used in an anatomic two-bundle approach to anterior cruciate ligament reconstruction. Fig. 1 The fetal knee demonstrates the two bundles of the anterior cruciate ligament: the anteromedial (AM) and the posterolateral (PL) bundle. LFC = lateral femoral condyle. Fetal, arthroscopic, and cadaver studies have shown that the anterior cruciate ligament consists of two functional bundles, the anteromedial bundle and the posterolateral bundle6-8 (Figs. 1, 2, and 3). The nomenclature of the two bundles corresponds to their tibial insertion sites. On the femoral side, the anteromedial bundle originates more proximally and the posterolateral bundle originates more distally. On the tibial side, the anteromedial bundle inserts anteromedially while the posterolateral bundle inserts posterolaterally. The relative position of the two bundles varies with the flexion angle of the knee. In extension, the two bundles are parallel. In flexion, the femoral insertion site of the posterolateral bundle moves anteriorly, and the …

MRI measurement of the 2 bundles of the normal anterior cruciate ligament.

Anatomical studies have shown that the normal anterior cruciate ligament (ACL) consists of 2 distinct functional bundles: the anteromedial and posterolateral bundles. To date, no study has assessed the magnetic resonance imaging (MRI) appearance of the anteromedial and posterolateral bundles. The purpose of this study was to measure the anteromedial and posterolateral bundles using high-field digital MRI. Fifty MRIs of the knees of 50 patients were prospectively collected using a 1.5-T magnet. The length and width of each ACL bundle was measured on sagittal and coronal digital MRIs, independently performed by 2 observers blinded to each others measurements. The average length and width of the anteromedial and posterolateral bundles were determined for all patients. Intraclass correlation coefficients were calculated to determine intertester test-retest reliability. In the sagittal plane, the anteromedial bundle averaged 36.9+/-2.8 mm in length and 5.1+/-0.7 mm in width. The posterolateral bundle, by contrast, averaged 20.5+/-2.4 mm in length and 4.4+/-0.8 mm in width. In the coronal plane, the width of the anteromedial bundle averaged 4.2+/-0.8 mm and of the posterolateral bundle averaged 3.7+/-0.8 mm. Interobserver reliability for length of the ACL in the sagittal plane was 0.85, with a 95% CI of 0.75 to 0.91 for the anteromedial bundle and 0.75 with a 95% CI of 0.60 to 0.85 for the posterolateral bundle. Providing precise measurement of the ACL anteromedial and posterolateral bundles on MRI may improve the ability to detect damage to 1 or both of the bundles following injury.

Assessment of normal ACL double bundle anatomy in standard viewing planes by magnetic resonance imaging

Anatomical studies show that the native ACL consists of two distinct functional bundles, termed the anteromedial (AM) and posterolateral (PL) bundles. The utility of using routine magnetic resonance imaging (MRI) to distinguish the individual bundles of the ACL has not been evaluated. The purpose of this study was to evaluate the intra- and inter-observer agreement for assessment of the AM and PL bundles using MRI in the axial, coronal, and sagittal viewing planes. We identified a series of patients seen in the senior author’s clinic during a 16-month period. Images were independently evaluated in blinded fashion at two separate time points by a musculoskeletal radiologist and two orthopaedic residents. The AM bundle was detected in most planes of view with high frequency and reliability, while detection of the PL bundle was less frequent and had a lower associated reliability. Our results indicate that it is difficult to reliably detect both the AM and PL bundles using a low-field strength magnet with standard planes of view. It has been demonstrated that the ACL may be imaged effectively in planes that are based on the natural course of the ligament, and it is likely that this will also facilitate visualization of the individual AM and PL bundles. The use of additional oblique planes of view offers a potential approach for improved evaluation of the ACL, even with low field strength magnets. Future work in this area may assist in the pre-operative assessment of isolated AM or PL bundle injuries, facilitating a more anatomic approach to ACL reconstruction.

Ulnar collateral ligament reconstruction using the ToggleLoc with ZipLoop for ulnar side fixation.

Dr Starman is from Carolinas Medical Center, and Drs Fleischli and D’Alessandro are from OrthoCarolina Sports Medicine Center, Charlotte, North Carolina; and Dr Morgan is from Resurgens Orthopaedics, Atlanta, Georgia. Drs Starman, Morgan, Fleischli, and D’Alessandro have no relevant fi nancial relationships to disclose. Correspondence should be addressed to: James S. Starman, MD, Department of Orthopedic Surgery, Carolinas Medical Center, 1616 Scott Ave, Charlotte, NC 28203 (jstarman20@msn.com). doi: 10.3928/01477447-20100329-16 In ulnar collateral ligament reconstruction, the Biomet Sports Medicine ToggleLoc with ZipLoop Technology may allow for a more anatomic tunnel position on the ulna and avoidance of tunnel complications associated with other techniques.