Transtibial Tunnel Research Articles

Medial Meniscal Root Avulsion: A Biomechanical Comparison of Four Different Repair Constructs (SS-67)

Medial Meniscal Root Avulsion: A Biomechanical Comparison of Four Different Repair Constructs (SS-67)

Clinical and Radiologic Outcomes of PCL Reconstruction Using Transtibial and Tibial Inlay Techniques (SS-03)

There is still debate about the optimal surgical technique for posterior cruciate ligament (PCL) reconstruction. We evaluated the clinical outcome and incidence of osteoarthritis after PCL reconstruction between the transtibial tunnel and the tibial inlay technique.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Was Superior to Conventional Single-Bundle Reconstruction

Hosalkar, Harish S. MD, MBMS(Orth), FCPS(Orth), DNB(Orth)1; Pandya, Nirav K. MD1; Wenger, Dennis R. MD1 Author Information

Arthroscopic transtibial single-bundle posterior cruciate ligament reconstruction using patellar tendon graft compared with hamstring tendon graft

The purpose of this study was to compare the outcomes of arthroscopic transtibial single-bundle posterior cruciate ligament reconstruction using autologous patellar tendon and hamstring tendon grafts. From 1998 to 2007, 59 patients with symptomatic isolated posterior cruciate ligament injury were included in this retrospective study. Twenty-five knees were reconstructed using bone-patellar tendon-bone graft, and 34 knees were reconstructed using hamstring graft. In both groups, surgical techniques were similar, except material of fixation screws. Patients were evaluated pre-operatively and post-operatively at the latest follow-up with several parameters, including symptoms, physical examination, outcome satisfaction, functional scores, radiography and complications. Average follow-up period was 51.6months in patellar tendon group and 51.1months in hamstring tendon group. Significantly more kneeling pain (32 vs. 3%), squatting pain (24 vs. 3%), anterior knee pain (36 vs. 3%), posterior drawer laxity and osteoarthritic change were shown in patellar tendon group than in hamstring tendon group post-operatively. No significant differences were found in other parameters between both groups. Several shortcomings, including anterior knee pain, squatting pain, kneeling pain and osteoarthritic change, have to be concerned when using patellar tendon autograft. In conclusion, hamstring tendon autograft may be a better choice for transtibial tunnel PCL reconstruction.

Medial portal technique for single-bundle anatomical Anterior Cruciate Ligament (ACL) reconstruction

The aim of the paper is to describe the medial portal technique for anatomical single-bundle anterior cruciate ligament (ACL) reconstruction. Placement of an ACL graft within the anatomical femoral and tibial attachment sites is critical to the success and clinical outcome of ACL reconstruction. Non-anatomical ACL graft placement is the most common technical error leading to recurrent instability following ACL reconstruction. ACL reconstruction has commonly been performed using a transtibial tunnel technique in which the ACL femoral tunnel is drilled through a tibial tunnel positioned in the posterior half of the native ACL tibial attachment site. ACL reconstruction performed using a transtibial tunnel technique often results in a vertical ACL graft, which may fail to control the combined motions of anterior tibial translation and internal tibial rotation which occur during the pivot-shift phenomenon. The inability of a vertically oriented ACL graft to control these combined motions may result in the patient experiencing continued symptoms of instability due to the pivot-shift phenomenon. The medial portal technique in which the ACL femoral tunnel is drilled through an anteromedial or accessory anteromedial portal allows consistent anatomical ACL tunnel placement. This paper describes the advantages of the medial portal technique, indications for the technique, patient positioning, proper portal placement, anatomical femoral and tibial tunnel placement, graft tensioning and fixation.

Posterior Cruciate Ligament: Focus on Conflicting Issues

There is little consensus on how to optimally reconstruct the posterior cruciate ligament (PCL) and the natural history of injured PCL is also unclear. The graft material (autograft vs. allograft), the type of tibial fixation (tibial inlay vs. transtibial tunnel), the femoral tunnel position within the femoral footprint (isometric, central, or eccentric), and the number of bundles in the reconstruction (1 bundle vs. 2 bundles) are among the many decisions that a surgeon must make in a PCL reconstruction. In addition, there is a paucity of information on rehabilitation after reconstruction of the PCL and posterolateral structures. This article focused on the conflicting issues regarding the PCL, and the scientific rationales behind some critical points are discussed.

Remnant Preservation is Helpful to Obtain Good Clinical Results in Posterior Cruciate Ligament Reconstruction: Comparison of Clinical Results of Three Techniques

BackgroundThe purpose of the present study was to compare the clinical results of 3 posterior cruciate ligament reconstruction techniques according to the time from injury to surgery and remnant PCL status and to evaluate the efficiency of each technique.MethodsThe records of 89 patients who underwent primary PCL reconstructions with a posterolateral corner sling were analyzed retrospectively. Thirty-four patients were treated by anterolateral bundle (ALB) reconstruction with preservation of the remnant PCL using a transtibial tunnel technique in the acute and subacute stages of injury (group 1). Forty patients were treated with remnant PCL tensioning and an ALB reconstruction using the modified inlay technique in the chronic stage (group 2), and fifteen patients were treated with double-bundle reconstruction using the modified inlay technique (group 3). The double-bundle reconstruction was performed if there was a very weak or no PCL remnant.ResultsThe mean side-to-side differences in posterior tibial translation on the stress radiographs were reduced from 10.1 ± 2.5 mm in group 1, 10.6 ± 2.4 mm in group 2, and 12.8 ± 3.2 mm in group 3 preoperatively to 2.3 ± 1.4 mm in group 1, 2.3 ± 1.5 mm in group 2, and 4.0 ± 2.5 mm in group 3 at the last follow-up (p < 0.001, p < 0.001, and p < 0.001, respectively). Statistical analyses revealed that group 1 and group 2 were similar in terms of side-to-side difference changes in posterior tibial translation on the stress radiographs; however, group 3 was inferior to group 1 and group 2 at the last follow-up (p = 0.022). The clinical results were not significantly different among the three groups.ConclusionsExcellent posterior stability and good clinical results were achieved with ALB reconstruction preserving the injured remnant PCL in the acute and subacute stages and remnant PCL tensioning with ALB reconstruction in the chronic stage. The PCL injuries could be surgically corrected with different techniques depending on both the remnant PCL status and the interval between the knee trauma and operation.

Root tear of the meniscus: biomechanical evaluation of an arthroscopic refixation technique

Aim of the current study was to evaluate the structural properties of an arthroscopic refixation technique for meniscal root tears. Arthroscopic two suture root tear refixation technique using a transtibial approach restores the structural properties of the intact meniscus attachment more closely than a one suture technique. Lateral root tear refixation was performed in a porcine knee model. Using a material testing machine, structural properties were determined after a cyclic loading protocol comparing transtibial tunnel reconstruction using one or a double suture technique. Intact posterior horn served as control group. Elongation after cyclic testing was significantly lower for intact and two suture technique when compared to single suture technique. Stiffness was significantly higher for intact constructs with a mean of 53.7 (±6.5) N/m and two suture technique with 44.8 (±9.9) N/m when compared to one suture technique with a mean of 37.1 (±5.4) N/m. In elongation and stiffness, no differences were found between intact and two suture technique. Ultimate failure loads were 325.6 (±77) N for the intact, 273.6 (±45.6) N for two suture technique and 149.8 (±24.3) N for the one suture technique. Both reconstruction techniques showed significantly lower ultimate failure load when compared to the intact control. Structural properties of root tear fixation using a transtibial single suture technique showed significantly higher elongation and lower stiffness and failure load after cyclic loading compared to the intact, whereas a two suture technique showed no difference in elongation and stiffness; however, lower failure load.

Repair of Lateral Meniscus Posterior Horn Detachment Lesions

Background: Posterior horn detachment (PHD) lesions of the lateral meniscus are commonly associated with acute anterior cruciate ligament (ACL) tears. Multiple surgeons have advocated for repair of this lesion at the time of ACL reconstruction. However, the biomechanical consequences of this lesion and its subsequent repair have not been evaluated. Hypothesis: The PHD lesion of the lateral meniscus will lead to increased tibiofemoral contact pressures, and repair of this lesion to bone via a tibial tunnel can restore normal contact pressures during simulated gait. Study Design: Controlled laboratory study. Methods: Lateral compartment contact pressures were measured via a sensor on the tibial plateau in 8 cadaver knees with the knee intact, after sectioning the posterior horn of the lateral meniscus to simulate PHD, and after repairing the injury. The repair was performed using an ACL tunnel guide to drill a tunnel from the anteromedial tibia to the posterior horn attachment site. Dynamic pressure data were continuously collected using a conductive ink pressure sensing system while each knee was moved through a physiological gait flexion cycle. Results: Posterior horn detachment caused a significant increase in tibiofemoral peak contact pressure from 2.8 MPa to 4.2 MPa (P = .03). After repair of the lesion to bone was performed through a transtibial tunnel, the peak contact pressure was 2.9 MPa. Posterior horn detachment also significantly decreased the maximum contact area over which tibiofemoral pressure is distributed from 451 mm2 in the intact state to 304 mm2 in the detached state. Repair of the PHD lesion increased the maximum contact area to 386 mm2, however, this area was also significantly less than in the intact state (P = .05). Conclusion: Posterior horn detachment of the lateral meniscus causes increased peak tibiofemoral contact pressure. The peak pressure can be reduced to a normal level with repair of the lesion to bone via a transtibial tunnel. Clinical Relevance: Posterior horn detachment of the lateral meniscus is a lesion often associated with an acute ACL tear. Debate exists concerning the importance of repairing PHD lesions at the time of ACL reconstruction. The data provided in this study may influence surgeons’ management of the lesion.

High incidence of tunnel widening after anterior cruciate ligament reconstruction with transtibial femoral tunnel placement

This study evaluated the incidence, amount, morphology and clinical significance of bone tunnel widening (TW) at a mean 5-year period after anterior cruciate ligament reconstruction (ACLR) with a transtibial drilling technique. Fifty-nine patients undergoing primary ACLR using quadrupled hamstring autografts, biodegradable transfemoral pins for femoral-sided and 2-mm oversized interference screws for tibial-sided graft fixation were followed up at a mean 61 months postoperatively. Patients were examined clinically and by MRI. Tunnel cross-sectional areas (CSA) were related to drill diameters, which were significantly correlated with radiographic tunnel sizes. Tunnel morphologies were assessed and their positions determined using an anatomical coordinate system. CSA had more than doubled in all segments measured (p < 0.0001) except at the femoral notch level. Greatest CSA increases were found at the femoral graft suspension point (122 %) and at the central tibial tunnel segment (134 %). 54 (92) and 56 (95 %) patients had significant TW, i.e., CSA increase of more than 50 %, in at least one tunnel segment femorally and tibially. Four different tunnel morphologies were observed, of which the linear type was most often encountered on either side. Mean side-to-side difference in anterior-posterior laxity was 1.0 ± 1.4 mm, while Lysholm, IKDC and Tegner activity scores were 90 ± 12, 84 ± 15 and 4 (1-9); clinical outcomes were not found to be correlated with tunnel sizes and morphologies as were tunnel positions and tunnel sizes. This study demonstrates that considerable TW occurs in virtually all patients in the mid term after ACLR using a transtibial drilling technique with 'high' femoral tunnel positions. Yet, neither amount nor morphology or tunnel position does affect knee stability or function.

Effect of Calcium Phosphate–Hybridized Tendon Graft in Anterior Cruciate Ligament Reconstruction

Background: The authors developed a novel technique to improve tendon-bone healing by hybridizing calcium phosphate (CaP) with a tendon graft using an alternating soaking process. Hypothesis: Anterior cruciate ligament (ACL) reconstruction using the CaP-hybridized tendon graft would have a better clinical outcome and reduce the percentage of bone tunnel enlargement compared with a conventional method because of the enhanced anchoring between the tendon graft and the bone. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients (N = 64) with unilateral ACL rupture underwent arthroscopically assisted single-bundle ACL reconstruction using a 4-strand semitendinosus tendon or 4-strand semitendinosus and gracilis tendons with EndoButton femoral fixation and screw washer tibial fixation. These patients were equally randomized to undergo the CaP (n = 32) or conventional (n = 32) method using a transtibial tunnel approach according to the closed envelope method. In the CaP group, the tendon graft was hybridized with the CaP at both ends of the graft. One surgeon performed all reconstructions without knowing which graft was prepared. Patients’ backgrounds regarding age at surgery, gender, period before surgery, and associated meniscal injuries were similar in the 2 groups. All patients followed the same postoperative protocol. At 1 and 2 years after surgery, they were evaluated with the manual knee laxity test, KT-1000 arthrometry, International Knee Documentation Committee (IKDC) examination form, Tegner scale, and Lysholm scale. Also, 1 year postoperatively, bone tunnel enlargement was analyzed using computed tomography, intensity of the tendon graft by magnetic resonance imaging (MRI), and tendon graft appearance by arthroscopic examination. All the examinations were performed blindly. Results: All patients underwent a minimum 2-year follow-up. KT-1000 arthrometry data indicated statistically significant decreased average anterior tibial translation in the CaP group compared with the conventional method group: 1.0 ± 2.0 mm versus 1.9 ± 1.6 mm (P < .05), respectively, at 1 year; 1.6 ± 2.1 mm versus 2.6 ± 2.4 mm (P < .05), respectively, at 2 years. The Lysholm score was higher in the CaP group than in the conventional method group at 2 years (96.9 ± 4.3 vs 91.7 ± 13.3, P < .05). The CaP-hybridized tendon graft reduced the percentage of bone tunnel enlargement of the anteroposterior diameter at the main joint aperture site 1 year postoperatively (femoral side: 15.5% ± 13.4% vs 22.1% ± 16.4%, P < .05; tibial side: 19.3% ± 17.1% vs 26.1% ± 13.7%, P < .05). The results of the pivot-shift test, IKDC grade, and Tegner score; the intensity of the tendon graft (MRI); and arthroscopic appearance were not significantly different at both follow-up periods in the 2 groups. Conclusion: The CaP-hybridized tendon graft improved anterior knee stability and Lysholm scores at the 2-year follow-up and improved anterior knee stability and reduced the percentage of bone tunnel enlargement in both tunnels at the 1-year follow-up compared with the conventional method for single-bundle ACL reconstruction. However, longer follow-up is needed to investigate the appearance of any increased instability.

Single Compared to Double-Bundle PCL Reconstruction Using Allograft Tissue

This study compares the results of arthroscopic transtibial tunnel single-bundle and double-bundle posterior cruciate ligament (PCL) reconstructions using allograft tissue in PCL-based multiple ligament injured knees. Ninety consecutive PCL reconstructions are evaluated: 45 single-bundle and 45 double-bundle reconstructions. All PCL reconstructions were performed using the arthroscopically assisted transtibial tunnel PCL reconstruction technique using fresh frozen allograft tissue from the same tissue bank. Achilles tendon allograft was used for the anterolateral bundle; tibialis anterior allograft was used for the posteromedial bundle. The knees were evaluated postoperatively, comparing the single-bundle results to the double-bundle results, with KT-1000 arthrometer (Medmetric Corporation, San Diego, CA) testing, three different knee ligament rating scales, and Telos stress radiography (Austin Associates, Fallston, MD). Both the single-bundle and the double-bundle PCL reconstruction surgical techniques using allograft tissue provide successful results in the PCL-based multiple ligament injured knee when evaluated with stress radiography, arthrometer measurements, and knee ligament rating scales.

The Relationship Between Femoral Tunnels Created by the Transtibial, Anteromedial Portal, and Outside-In Techniques and the Anterior Cruciate Ligament Footprint

Background: Tunnels created for reconstruction of a torn anterior cruciate ligament (ACL) are critical determinants of joint stability and clinical outcomes. There is limited objective evidence on the ability of transtibial (TT), anteromedial (AM) portal, and outside-in (OI) operative techniques in creating anatomic tunnels. Hypothesis: (1) Tibial tunnel–independent techniques can create tunnels more accurately at the anatomic ACL footprint center than the TT technique, and (2) femoral tunnel exit location of the OI and TT techniques on the lateral cortex will be significantly further away from the lateral epicondyle than the femoral tunnel exit location of the AM portal technique. Study Design: Controlled laboratory study. Methods: Eight cadaveric knee specimens with a mean age of 56 years were used in this study. A digitizing system was used to record points along the outlines of the ACL insertion area and apertures of tunnels created by the TT, AM portal, and OI techniques. The following parameters were measured from the digitized points: (1) amount of ACL, anteromedial bundle, and posterolateral bundle coverage by the tunnels; (2) relationship between the centers of the ACL and the tunnels; and (3) distance between the center of the femoral tunnel exit and the lateral epicondyle. All the recorded parameters were analyzed in 3-dimensional solid modeling software. Results: The percentage of ACL footprint coverage achieved by all 3 surgical techniques was not significantly different from one another. However, larger femoral posterolateral bundle coverage was observed in tunnels created by the AM portal and OI techniques than in the TT tunnel. In terms of anteromedial bundle coverage, no significant differences were observed between the 3 techniques. On average, 27.1% ± 17.4% of the TT tunnel was outside the ACL footprint. This was significantly larger compared with 13.6% ± 15.7% with the AM portal technique (P = .01) and 10.8% ± 10.8% in the OI technique (P = .01). Centers of femoral tunnels created by the TT, AM portal, and OI techniques were located at a distance of 3.0 ± 1.5 mm, 2.1 ± 0.9 mm, and 1.5 ± 1.2 mm, respectively, from the ACL footprint center. The femoral tunnel exit location of the AM portal technique on the lateral femoral cortex was closer to the lateral epicondyle than the femoral tunnel exit location of the OI and TT techniques. Conclusion: Findings of this study indicate that a larger posterolateral bundle coverage is achieved by the AM portal and OI techniques than by the TT technique. Centers of the tunnels created by the AM portal and OI techniques were closer to the native ACL footprint center than the center of the TT technique tunnel. The incidence of a posterior femoral tunnel exit relative to the lateral epicondyle is higher in the AM portal technique than in the OI and TT techniques. Clinical Relevance: For ACL reconstruction using soft tissue grafts, tibial tunnel–independent techniques can produce more anatomic tunnels than the TT technique.

Influence of knee flexion and femoral cross-pin insertion angle on posterolateral structures of the knee and lateral fixation lengths during ACL reconstruction

Some studies have investigated knee flexion angle on the sagittal plane and insertion angle of the cross-pin on the coronal plane to evaluate proper femoral fixation. They evaluated the possibilities of injury to the posterolateral (PL) and neurovascular structures using several methods. The purposes of this study were to evaluate (1) the influence of knee flexion and femoral cross-pin insertion angles on knee PL structures and (2) the lateral fixation length of the cross-pin. Ten fresh cadaveric knees with no previous surgeries around the knee were used. Transtibial femoral tunnels (1:30 or 10:30 o'clock position) were made at three different knee flexion angles (70°, 90°, and 110°). Two cross-pin guidewires (superior and inferior pins) were drilled at three different insertion angles [downward 30°, 0° (parallel to floor line), and upward 30°] for each knee flexion position. The distances from the insertion point of the two cross-pins to the lateral collateral ligament (LCL) and popliteus tendon (PT), and the distance from the lateral wall of the femoral tunnel to the lateral cortex of the femoral condyle were measured. No significant differences were observed in the superior and inferior pin depths (p=0.56 and 0.39). The distances from the superior pin to the LCL and from the inferior pin to the LCL were significantly shorter in all knee flexions with 0° and an upward 30° insertion angle than with 70° and 90° knee flexion with a downward 30° insertion angle, respectively (superior pin: p=0.02 and 0.03; inferior pin: p=0.03 and 0.03). No significant difference was observed in the distance between the superior pin and inferior pins and the PT (p=0.25). The cross-pin was inserted close to the LCL and PT, and a downward 30° angle was the safest insertion angle. Lateral fixation length was sufficient for the cross-pin fixation in the 10:30- or 1:30-positioned femoral tunnel.

Isolated and Combined Grade-III Posterior Cruciate Ligament Tears Treated with Double-Bundle Reconstruction with Use of Endoscopically Placed Femoral Tunnels and Grafts

A variety of techniques have been developed to improve clinical outcomes and objective knee stability following posterior cruciate ligament (PCL) reconstruction. Additional refinements in surgical and rehabilitation techniques are necessary for improvement of both subjective and objective outcomes. All patients studied underwent endoscopic PCL reconstruction with a double-bundle allograft. All of the allografts were placed into the femoral tunnel through a lateral arthroscopic portal, secured by an all-inside method, and were passed distally through a transtibial tunnel. Modified Cincinnati subjective and International Knee Documentation Committee (IKDC) subjective and objective outcome scores and posterior stress radiographs of the knee were made preoperatively and at the time of final follow-up. There were a total of thirty-nine patients, including thirty-three male and six female patients, with an average age of thirty-three years. There were seven isolated PCL reconstructions and thirty-two combined reconstructions of the knee. Eight patients were not available for follow-up at a minimum of two years, leaving a cohort of thirty-one patients. Preoperative Cincinnati and IKDC subjective scores averaged 34.5 and 39.3, respectively. These scores improved significantly to 73.2 and 74.3, respectively, at an average of 2.5 years postoperatively. On posterior stress radiographs, the average posterior tibial translation of the knees was 15 mm preoperatively and improved significantly to 0.9 mm postoperatively. Patients undergoing double-bundle PCL reconstruction with use of endoscopic placement of femoral tunnels had significant improvements in subjective and objective outcome scores and with objective knee stability.

Comparison of femoral tunnels between transtibial tunnel and anteromedial portal drillings in anterior cruciate ligament reconstruction

ObjectiveTo compare lengths and angles of the femoral tunnels which are drilled by transtibial technique and through the anteromedial portal in arthroscopic anterior cruciate ligament (ACL) reconstruction.MethodsFrom November 2000 to November 2009, 102 patients underwent ACL reconstruction. Their femoral tunnels were drilled by transtibial technique in 50 patients (39 men and 11 women with an average age of 27.9 ±7. 6 years) and through anteromedial arthroscopic portal in 52 (33 men and 19 women with an average age of 30. 5 ± 10. 7 years) . The femoral tunnel lengths were recorded during surgery and tunnel angles on coronal and sagittal planes were measured on postoperative X-ray films for statistical analysis (student t test with a significant level of 0. 05 ).ResultsThe mean length of femoral tunnel by transtibial technique (50. 9 ± 5.0 mm) was significantly larger than that through anteromedial portal (37.8 ± 4. 7 mm) ( t =15. 083, P =0. 000). The mean angles of femoral tunnel by transtibial technique on coronal plane (68. 6°± 7.0°) and on sagittal plane (45. 1°± 8.1°) were significantly larger than those through anteromedial portal on coronal plane (49. 8° ± 7.7°) and on sagittal plane (33.7° ± 9. 7°) ( t =12. 874, P =0. 000; t =5. 877, P =O. 000) .ConclusionBecause the femoral tunnel drilled through anteromedial portal is significantly shorter in length and smaller in angles, it can lead to potentially better clinical outcomes in arthroscopic ACL reconstruction. Key words: Anterior cruciate ligament; Arthroscopy; Bone tunnel

Double Bundle Posterior Cruciate Ligament Reconstruction

The keys to successful posterior cruciate ligament reconstruction are to identify and treat all pathology, use strong graft material, accurately place tunnels in anatomic insertion sites, minimize graft bending, use a mechanical graft tensioning device, use primary and back-up graft fixation, and use the appropriate postoperative rehabilitation program. Adherence to these technical principles results in successful single and double-bundle arthroscopic transtibial tunnel posterior cruciate ligament reconstruction based upon stress radiography, arthrometer, knee ligament rating scales, and patient satisfaction measurements.

Arthroscopic Double-Bundle Posterior Cruciate Ligament Reconstruction Surgical Technique

The keys to successful posterior cruciate ligament (PCL) reconstruction are to identify and treat all pathology, use strong graft material, accurately place tunnels in anatomic insertion sites, minimize graft bending, use a mechanical graft tensioning device, use primary and back-up graft fixation, and use the appropriate postoperative rehabilitation program. Adherence to these technical principles results in successful single-bundle and double-bundle arthroscopic transtibial tunnel PCL reconstruction based on stress radiography, arthrometer, knee ligament rating scales, and patient satisfaction measurements.

Prevalence of Nonanatomical Graft Placement in a Series of Failed Anterior Cruciate Ligament Reconstructions

Background Anterior cruciate ligament reconstruction employing transtibial tunnel techniques may result in less than ideal femoral and tibial vertical graft placement, with a residual pivot shift and instability symptoms. Hypothesis Nonanatomical graft placement is highly prevalent among knees with failed primary and revision anterior cruciate ligament grafts. Study Design Case series; Level of evidence, 4. Methods A total of 122 consecutive patients presented to the authors’ center with a failed anterior cruciate ligament reconstruction. Radiographs, magnetic resonance imaging, and operative reports were used to define graft placement. Arthroscopic confirmation of graft placement was obtained in 92 knees during subsequent revision surgery. A nonanatomical graft placement was assigned when ≥50% of the graft was outside of the native tibial and femoral insertions. All patients prospectively completed Cincinnati Knee Rating System questionnaires. Results A nonanatomical graft placement occurred in 107 of 122 (88%) knees; 61% of the grafts were entirely on the intercondylar femoral roof, and 35% extended posterior to the anterior cruciate ligament tibial attachment. A transtibial technique had been used in 83%. The mean values for the coronal and sagittal graft placement showed a significantly increased vertical orientation in comparison with a control group (P < .01). Forty-two of the 107 nonanatomical grafts had undergone 1 or more revisions without correction of the misplaced graft tunnels, and these subsequently failed. Conclusion The occurrence of nonanatomical graft placement in primary and revision knees may represent an inadequacy of transtibial tunnel drilling techniques to obtain graft placement within the native femoral and tibial footprints. In revision cases, the prior graft location requires close scrutiny so the new graft tunnels are placed at the native anterior cruciate ligament attachments. Independent drilling of tibial and femoral tunnels is recommended using either 2-incision or anteromedial portal techniques.

Comparing Stability of Different Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction Techniques: A Cadaveric Study Using Navigation

The objective of this study was to analyze 2 different single-bundle anterior cruciate ligament (ACL) reconstruction procedures and compare their ability to reduce the pivot-shift phenomenon with an anatomic double-bundle (DB) technique. Twelve fresh-frozen cadaveric hip-to-toe lower extremity specimens were used. ACL reconstructions were performed by conventional single-bundle, anteromedial (AM) single-bundle, and DB techniques. Anterior tibial translation was measured in the intact knee, ACL-deficient knee, and the 3 ACL reconstructions in response to a Lachman test and a mechanized pivot-shift test. A surgical navigation system (Praxim Medivision, Grenoble, France) simultaneously tracked kinematics. Intact knees were clinically graded as grade 0 (n = 12). ACL-deficient knees were graded as grade 1 (n = 10) and grade 2 (n = 2). With a mechanized pivot-shift test, anterior tibial translation was 1.7 +/- 3.0 mm, 9.7 +/- 3.8 mm, 4.4 +/- 1.0 mm, 1.8 +/- 1.5 mm, and -1.7 +/- 3.3 mm for intact knees, ACL-deficient knees, conventional technique, AM technique, and DB technique, respectively. There was a significant difference between the DB technique and both single-bundle techniques tested (P < .05). The model used represents an isolated ACL injury without concomitant injury to the capsuloligamentous restraints or menisci. However, during the pivot shift, neither type of single-bundle ACL reconstruction stabilized the knee to the same degree as the DB ACL reconstruction. In this cadaveric model a DB repair offers great anterior and rotational stability. Although this study suggests that the DB technique is biomechanically superior to a single-bundle technique using traditional transtibial tunnel positions, there appear to be minimal differences in knee kinematics during stability testing with the DB technique versus an AM graft position. Indeed, compared with the AM position alone, the DB technique "overconstrained" the kinematics of the knee during a pivoting maneuver at time zero in a cadaveric model with an isolated ACL injury.