Anterior cruciate ligament reconstruction using the Bio-TransFix femoral fixation device and anteromedial portal technique

No differences in clinical outcomes and graft healing between anteromedial and central femoral tunnel placement after single bundle ACL reconstruction

PURPOSE

The purpose of this study was to compare clinical outcomes and graft healing after anterior cruciate ligament (ACL) reconstruction with anteromedial and central femoral tunnel placement.

METHODS

During 2016 and 2018, 110 consecutive patients underwent single bundle ACL reconstruction; 85 patients met the inclusion criteria, and each patient underwent 3D-CT within 1 week and MRI 1.5 years after the operation. The central point of the femoral tunnel and signal/noise quotient (SNQ) of three regions of interest (ROI) in the intra-articular graft were measured to analyse the tunnel position and graft healing extent. Clinical assessments, including functional scores, KT-2000 arthrometer measurements and pivot-shift tests, were evaluated at the 2-year follow-up. Patients were divided into two groups depending on the femoral tunnel position: the anteromedial position group (Group A) and the centre position group (Group B).

RESULTS

Seventy-one patients were available for the 2-year follow-up and MRI examination: 34 patients in Group A and 35 patients in Group B, and 2 patients were excluded for an eccentric tunnel position. No graft failure occurred, and compared with the preoperative assessment outcomes, the outcomes of both groups improved at the final follow-up. Group A was significantly better than Group B regarding the KT-2000 arthrometer measurements (P = 0.031). No significant differences were observed in terms of functional scores, pivot-shift test results, or the SNQ between groups.

CONCLUSIONS

No differences in clinical outcomes or graft healing were found between AM and central femoral tunnel placements in single bundle ACL reconstruction. Therefore, satisfactory clinical outcomes, knee stability and graft healing can be obtained for both femoral tunnel placements.

LEVEL OF EVIDENCE

II.

Anterior cruciate ligament femoral-tunnel drilling through an anteromedial portal: 3-dimensional plane drilling angle affects tunnel length relative to notchplasty

Background

Notchplasty is a surgical technique often performed during anterior cruciate ligament reconstruction (ACLR) with widening of the intercondylar notch of the lateral distal femur to avoid graft impingement. The purpose of this study was to correlate femoral-tunnel length with 3-dimensional (3D) drilling angle through the anteromedial (AM) portal with and without notchplasty.

Materials and methods

Computer data were collected from an anatomical study using 16 cadaveric knees. The anterior cruciate ligament (ACL) femoral insertion was dissected and outlined for gross anatomical observation. The dissected cadaveric knees were scanned by computed tomography (CT). Three-dimensional measurements were calculated using software (Geomagic, Inc., Research Triangle Park, NC, USA) and included the center of the ACL footprint and the size of the ACL femoral footprint. The femoral-tunnel aperture centers were measured in the anatomical posterior-to-anterior and proximal-to-distal directions using Bernard’s quadrant method. The ACL tunnel was created 3-demensionally in the anatomical center of femoral foot print of ACL using software (SolidWorks®, Corp., Waltham, MA, USA). The 8-mm cylinder shaped ACL tunnel was rested upon the anatomical center of the ACL footprint and placed in three different positions: the coronal plane, the sagittal plane, and the axial plane. Finally, the effect of notchplasty on the femoral-tunnel length and center of the ACL footprint were measured. All the above-mentioned studies performed ACLR using the AM portal.

Results

The length of the femoral tunnels produced using the low coronal and high axial angles with 5-mm notchplasty became significantly shorter as the femoral starting position became more horizontal. The result was 30.38 ± 2.11 mm on average at 20° in the coronal plane/70° in the axial plane/45° in the sagittal plane and 31.26 ± 2.08 mm at 30° in the coronal plane/60° in the axial plane/45° in the sagittal plane, respectively, comparing the standard technique of 45° in the coronal/45° in the axial/45° in the sagittal plane of 32.98 ± 3.04 mm (P < 0.001). The tunnels made using the high coronal and low axial angles with notchplasty became longer than those made using the standard technique: 40.31 ± 3.36 mm at 60° in the coronal plane/30° in the axial plane/45° in the sagittal plane and 50.46 ± 3.13 mm at 75° in the coronal plane/15° in the axial plane/45° in the sagittal plane (P < 0.001).

Conclusions

Our results show that excessive notchplasty causes the femoral tunnel to be located in the non-anatomical center of the ACL footprint and reduces the femoral-tunnel length. Therefore, care should be taken to avoid excessive notchplasty when performing this operation.

ACL Reconstruction Graft Angle and Outcomes: Transtibial vs Anteromedial Reconstruction

BACKGROUND

The importance of creating an anatomic anterior cruciate ligament (ACL) reconstruction has been receiving significant attention. The best technique by which to achieve this anatomic reconstruction continues to be debated. The two most common methods are the transtibial (TT) and anteromedial (AM) techniques. Each has its advantages and disadvantages, and the literature comparing the two remains uncertain.

QUESTIONS/PURPOSES

In this prospective comparative study, we aimed to compare the ACL graft and tunnel angles achieved using the anatomic transtibial (TT) and anteromedial (AM) techniques; compare the ACL graft and tunnel angles in knees that have undergone ACL reconstruction and knees with intact ACLs; and determine whether differences in the graft or tunnel angle produce differences in clinical outcomes, as measured using both physical exam and patient-reported outcomes, after ACL reconstruction.

METHODS

Patients who underwent primary ACL reconstruction with bone-tendon-bone grafts using a TT or AM technique were included. Femoral graft angle (FGA), tibial graft angle (TGA), and sagittal orientation of the reconstructed ACL and contralateral native ACL were measured on post-operative magnetic resonance imaging. Post-operatively, patients underwent measurement of knee stability and completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) survey.

RESULTS

Twenty-nine patients were enrolled (AM group, 14; TT group, 15); at follow-up, KOOS data were available for 26 patients (13 in each group). There were no differences in sagittal ACL graft angle between groups or in comparison with the normal knee. The FGA was more vertical after TT reconstructions; the TGA was comparable between groups. There were no significant differences in 2-year post-operative physical exam measurements or in KOOS scores.

CONCLUSION

Anatomic ACL angle was restored after reconstruction with both the TT and AM techniques, despite different FGAs. No significant differences in clinical outcome were noted between groups on physical exam or KOOS at 2 years after surgery. These results suggest that TT reconstruction results in a graft position similar to that seen in AM reconstruction and that the location of the intra-articular tunnel aperture matters more than the orientation of the tunnel.

Femoral tunnel positioning using an anteromedial technique for ACL reconstruction: A radiographic study with a cadaveric model

BACKGROUND

We studied the anatomic positioning of the femoral tunnel during simulated anterior cruciate ligament reconstruction using an anteromedial portal approach in cadaveric models.

METHODS

In thirty cadaveric human knee specimens, simulation of an arthroscopic anterior cruciate ligament reconstruction was performed and the femoral tunnel was drilled using an anteromedial portal. A Kirschner wire was passed into the tunnel and radiographs were obtained. These radiographs were then evaluated in the coronal and sagittal planes. Angles between the axis of the femoral tunnel and the joint line in the coronal plane (alpha, α) or the femoral long axis in the sagittal plane (beta, β) were calculated for each specimen. The external aperture of the femoral tunnel was defined as the point of exit of the Kirschner wire from the lateral femoral cortex. This was evaluated relative to a prescribed rectangle and coordinate axis, with the radiographic quadrant method of Bernard, to assess the accuracy of femoral tunnel placement.

RESULTS

The mean α in the coronal plane was 48.53∘, the mean β in the sagittal plane was 32.23∘. All of the femoral tunnel external apertures were located outside of the rectangleCONCLUSION: We evaluated the positioning of the femoral tunnel and the external aperture of the femoral tunnel with the anteromedial portal technique. This study provides a reference standard to assess accurately femoral tunnel positioning on postoperative radiographs.

Reconstruction of the anterior cruciate ligament by means of an anteromedial portal and femoral fixation using Rigidfix

Objective

To evaluate a series of patients who underwent surgery for reconstruction of the anterior cruciate ligament with flexor tendons, by means of the anteromedial transportal technique using Rigidfix for femoral fixation, and to analyze the positioning of the pins by means of tomography.

Methods

Thirty-two patients were included in the study. The clinical evaluation was done using the Lysholm, subjective IKDC and Rolimeter. All of them underwent computed tomography with 3D reconstruction in order to evaluate the entry point and positioning of the Rigidfix pins in relation to the joint cartilage of the lateral condyle of the femur.

Results

The mean Lysholm score obtained was 87.81 and the subjective IKDC was 83.72. Among the 32 patients evaluated, 43% returned to activities that were considered to be very vigorous, 9% vigorous, 37.5% moderate and 12.5% light. In 16 patients (50%), the distal entry point of the Rigidfix pin was located outside of the cartilage (extracartilage); in seven (21.87%), the distal pin injured the joint cartilage (intracartilage); and in nine (28.12%), it was at the border of the lateral condyle of the femur.

Conclusion

The patients who underwent ACL reconstruction by means of the anteromedial transportal using the Rigidfix system presented satisfactory clinical results over the length of follow-up evaluated. However, the risk of lesions of the joint cartilage from the distal Rigidfix pin needs to be taken into consideration when the technique via an anteromedial portal is used. Further studies with larger numbers of patients and longer follow-up times should be conducted for better evaluation.

Time and Cost of Diagnosis for Symptomatic Femoroacetabular Impingement

Background:

Femoroacetabular impingement (FAI) and labral tears are common causes of hip pain that are often not promptly or properly diagnosed. To our knowledge, no reports have defined the time and cost of diagnosis of labral tears associated with FAI.

Hypothesis:

Patients with labral tears associated with FAI undergo extraneous diagnostic testing and pain and incur a significant amount of health care costs before they receive appropriate surgical management for their pathology.

Study Design:

Economic and decision analysis; Level of evidence, 4.

Methods:

A total of 78 patients diagnosed with symptomatic FAI were surveyed. A standardized questionnaire asked patients about time to diagnosis, symptoms, health care providers visited, imaging tests, and treatments prior to diagnosis. Costs were calculated based on 2012 national Medicare data.

Results:

Patients in the cohort saw an average of 4.0 health care providers, had an average of 3.4 diagnostic imaging tests, and tried an average of 3.1 treatments prior to diagnosis. The average total amount spent per patient prior to diagnosis was US$2456.97. The calculated minimum cost of diagnosis, including a visit to an orthopaedic surgeon as well as an anteroposterior pelvis and lateral hip radiograph and 1 magnetic resonance arthrogram, was US$690.62. The average duration between onset of symptoms and diagnosis of labral tear was 32.0 months.

Conclusion:

The average amount of health care dollars spent per patient prior to receiving a diagnosis of acetabular labral tear was US$1766.35 higher than the calculated minimum cost. This figure is based on Medicare payment amounts, which may significantly underestimate the actual charges at many hospitals, thereby increasing the total cost of diagnosis.

Clinical Relevance:

The costs and pain associated with this time, along with the potential long-term degradation of the hip joint, make it important for all health care professionals to recognize and appropriately manage or refer the patient.

Anterior-Posterior Instability of the Knee Following ACL Reconstruction with Bone-Patellar Tendon-Bone Ligament in Comparison with Four-Strand Hamstrings Autograft

Purpose. To evaluate anterior-posterior knee laxity using two different autografts. Material-Methods. 40 patients, (34 males and 6 women), 17-54 years old (mean: 31), were included in the present study. Group A (4SHS = 20) underwent reconstruction using four-strand hamstrings, and group B (BPBT = 20) underwent reconstruction using bone-patellar tendon-bone autograft. Using the KT-1000 arthrometer, knee instability was calculated in both knees of all patients preoperatively and 3, 6, and 12 months after surgery at the ACL-operated knee. The contralateral healthy knee was used as an internal control group. Results. Anterior-posterior instability using the KT1000 Arthrometer was found to be increased after ACL insufficiency. The recorded laxity improved after arthroscopic ACL reconstruction in both groups. However, statistically significant greater values were detected in the bone-patellar tendon-bone group, which revealed reduction of anteroposterior stability values to an extent, where no statistical significance with the normal values even after 3 months after surgery was observed. Conclusions. Anterior-Posterior instability of the knee improved significantly after arthroscopic ACL reconstruction. The bone-patellar tendon-bone graft provided an obvious greater stability.

Anterior cruciate ligament reconstruction using biodegradable transfemoral fixation at 5-year follow-up: clinical and magnetic resonance imaging evaluation

PURPOSE

Biodegradable transfemoral graft fixation devices used in anterior cruciate ligament (ACL) reconstruction have recently been reported to precociously lose structural integrity.

METHODS

This study investigated outcomes after ACL reconstruction using hamstring grafts and biodegradable transfemoral fixation at 5-year follow-up. The condition of both graft and fixation device was evaluated by magnetic resonance imaging (MRI) and related to clinical outcomes. In total, 85 patients on whom index ACL reconstructive surgery by means of a quadrupled semitendinosus-gracilis graft and biodegradable transfemoral fixation was performed were included in the study.

RESULTS

Fifty-nine patients could be assessed by clinical and MRI examinations at a mean follow-up of 61 months (range, 52-69 months). Completely intact pins were found in 17 patients (29%), intact pins with delicate areas of resorption in 8 patients (14%), pin deformation in 5 patients (8%), pin fracture in 22 patients (37%) and pin migration in 3 patients (5%). In 40 patients (68%), pins had undergone degradation at the graft suspension point. Hamstring graft integrity and signal intensity scores were found to be significantly higher in patients with deformed, broken or dislocated pins as compared to patients with fully or mainly intact pins. Clinically, the mean side-to-side difference in anterior-posterior-laxity was 1.1 ± 1.6 mm, while Lysholm, IKDC and Tegner scores were 89 ± 11, 84 ± 14 and 4 (1-9). No statistically significant correlation was found between pin condition and clinical outcomes.

CONCLUSION

Biodegradable fixation pins lose structural integrity in a way that suggests continuous loading of the pin/graft construct, thereby questioning osseous incorporation of the graft. This situation is clinically relevant in terms of improved graft condition.

LEVEL OF EVIDENCE

Retrospective case series, Level III.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Normal sagittal of the anterior cruciate ligament can be reproduced using accessory anteromedial portal technique: a magnetic resonance imaging study

INTRODUCTION

Over time, the need for anatomic anterior cruciate ligament (ACL) to restore normal kinematics and postoperative function of the knee has been accepted. The purpose of this study was to compare the sagittal alignment of reconstructed ACL, which is performed between transtibial (TT) technique and accessory anteromedial (AAM) portal technique and between the reconstructed and the normal side in the same patient. In addition, we used the head of a metallic femoral interference screw as a reference to measure the femoral tunnel position.

PATIENTS AND METHODS

This was a retrospective study with 15 patients in each group: accessory anteromedial portal technique (n = 15), TT technique (n = 15) and contralateral normal side of each technique group (15 knees per technique). Magnetic resonance images of the ACL sagittal angle and radiographs of the coronal screw angle were used for comparing the two groups. The paired t test was used to compare operated and contralateral normal knee and independent t test was used to compare the TT and the AAM groups.

RESULTS

The sagittal angle of ACL of AAM technique (51.6 ± 3.3°) was not different from the normal side (50.8 ± 2.1°) (P = 0.270), however that of the TT technique (59.9 ± 5.7°) was significantly different from the normal side (50.9 ± 2.4°) (P < 0.001). The sagittal angle of AAM technique was significantly lower than that of the TT technique (P < 0.001). The coronal angle of the screw to axis of the femur in AAM technique (51.7 ± 3.8°) was more horizontal than that of the TT technique (24.4 ± 8.9°) (P < 0.001). The center of the screw head of the AAM technique was 30.7 ± 3.1 % of the Blumensaat line and 39.2 ± 5.2 % of the condylar height.

CONCLUSION

The anatomic sagittal angle of ACL can be achieved using the AAM technique compared with the TT technique. In addition, the angle of the screw in coronal plane was more horizontal using the AAM technique than with use of the TT technique.

LEVEL OF EVIDENCE

Level III, diagnostic study.

ACL reconstruction: comparison between transtibial and anteromedial portal techniques

PURPOSE

The purpose of this study was to compare the transtibial reconstruction technique of the anterior cruciate ligament (ACL) with the anteromedial (AM) portal technique in their ability to place the femoral and tibial tunnels within the ACL footprints.

METHODS

Forty patients were sequentially enrolled in two different surgical techniques, 20 patients in the transtibial and 20 patients in the AM portal technique. All patients underwent computed tomography scan of the operated knee. The center of the femoral tunnel aperture on the lateral femoral condyle was measured according to the quadrant method. On the tibial side, the center of the tibial tunnel was measured in the sagittal plane. These measurements were compared with the center of the normal AM and PL bundles.

RESULTS

There were no differences in the center of the femoral tunnels on the Blumensaat's line between the two groups (mean 23.5% (4.2) for the transtibial technique and 26.0% (4.3) for the AM portal technique (P = n.s.). In the height of the femoral condyle, the center of the tunnels was significantly lower in the AM portal technique group [mean 34.7% (3.8) vs. 24.0% (7.9) (P < 0.001)]. In the tibia, the center of the tunnel in the sagittal plane was significantly posterior in the transtibial technique (mean 55.4% (4.9) vs. 44.4% (3.7) (P < 0.001).

CONCLUSIONS

The AM portal technique places the femoral and tibial tunnels more centrally in the ACL footprint when compared with the transtibial technique.

LEVEL OF EVIDENCE

II.

Improved outcomes after anterior cruciate ligament reconstruction with quadrupled hamstring autografts and additional bone plug augmentation at five year follow-up

PURPOSE

Hybrid fixation has been proposed to improve outcomes of anterior cruciate ligament (ACL) reconstructions. This study evaluated midterm outcomes after transfemoral graft fixation using either a conventional or a modified technique using additional bone plug augmentation (BPA) of the femoral tunnel aperture.

METHODS

Seventy-one consecutive patients undergoing ACL reconstruction using a quadrupled hamstring autograft with transfemoral graft fixation and tibial interference screw fixation were included. Of these, 56 patients could be followed up 61 months (range 52-69 months) after ACL reconstruction both clinically and by magnetic resonance imaging (group A, conventional technique, n = 34; group B, modified technique, n = 22). Anteroposterior (AP) laxity measurements and International Knee Documentation Committee (IKDC), Lysholm and Tegner activity scoring were performed, while imaging included assessment of bone tunnel diameters, graft condition and graft filling at the femoral bone tunnel aperture.

RESULTS

Patients with additional BPA had a significantly higher degree of graft filling at the femoral bone tunnel aperture (p = .0135) and 'healthier' grafts (p = .0495). They also tended to display less AP laxity difference in terms of mean differences and total patient numbers. Lysholm, IKDC and Tegner activity index scores and bone tunnel diameters were not significantly different.

CONCLUSIONS

Additional BPA is an easy-to-perform, cheap and safe manoeuvre, which has the capacity to improve morphological and clinical outcomes at five year follow-up. However, femoral tunnel widening is unaffected by additional BPA.

Accidental perforation of the lateral femoral cortex in ACL reconstruction: an investigation of mechanical properties of different fixation techniques

PURPOSE

The aim of this study was to evaluate the mechanical properties of anterior cruciate ligament (ACL) reconstruction using the medial portal technique with cortical fixation and hybrid fixation after penetration of the lateral cortex by use of different drill sizes.

METHODS

In this biomechanical study a porcine in vitro model was used. The testing protocol consisted of a cyclic loading protocol (1,000 cycles, 50 and 250 N) and subsequent ultimate failure testing. Number of cyclic loadings survived, stiffness, yield load, maximum load, and graft elongation, as well as failure mode, were analyzed after ACL reconstruction with 5- to 9-mm soft-tissue grafts. In the control group, conventional penetration of the lateral cortex with a 4.5-mm drill and cortical fixation were performed. In the tested groups, the lateral cortex was penetrated with a drill matching the graft size. In the first part of the study, we used cortical fixation. In the second part, we used hybrid fixation with an interference screw.

RESULTS

In the first part of the study, ACL reconstruction with 5- to 6-mm perforation of the lateral cortex showed no significant differences in ultimate failure load after cyclic loading compared with the control group (P > .05). Specimens with reconstruction with 7- to 9-mm perforation of the lateral cortex and cortical fixation did not survive the cyclic loading protocol. In the second part of the study, with a hybrid fixation technique, ultimate failure testing after cyclic loading of specimens with 7- to 9-mm penetration showed no significant differences in tested parameters compared with the control group (P > .05).

CONCLUSIONS

After penetration of the lateral cortex with a drill size of more than 6 mm, cortical ACL fixation results in poor mechanical properties. Hybrid fixation increases the mechanical properties significantly after penetration with a 7- to 9-mm drill.

CLINICAL RELEVANCE

We advise caution to avoid penetration of the lateral femoral cortex when using cortical flip-button fixation. In case of accidental perforation of the lateral cortex with a diameter greater than 6 mm, we recommend performing hybrid fixation.

Use of transtibial aimer via the accessory anteromedial portal to identify the center of the ACL footprint

PURPOSE

To assess the ability of a transtibial aimer with a 7-mm off-set in a standardized position to reach the center of the ACL footprint on the femur through the AM portal.

METHODS

Nineteen cadaveric knees were dissected, and the perimeter of the femoral ACL footprint was marked. The aimer was placed just superior to the medial joint line close to the medial condyle through the AM portal. The guide was rested upon the posterior cortex and placed in three different positions: (A) at zero degrees in frontal plane and 60° in axial plane, (B) at 45° in frontal and 45° in axial, and (C) at the center of the ACL insertion site under direct visualization. A digital camera was used to take pictures on the axial plane, and Image J software was used for angle measurement. Aluminum beads were used to mark the three positions indicated by the aimer, and CT scans were performed. The distances from the true center of the ACL to each point were determined.

RESULTS

Position A resulted in femoral tunnel placement furthest from the center of the ACL footprint (8.6 mm). Position B was at a distance of 3.2 mm, and position C was the most accurate, with an average distance of 2.0 mm. The angles required by Position C varied with an average of 54° ± 11° in the frontal plane and an average of 44° ± 6° in the axial plane.

CONCLUSION

The 7-mm transtibial aimer was unable to reach the center of ACL footprint at a fixed orientation.

Development of a femoral template for computer-assisted tunnel placement in anatomical double-bundle ACL reconstruction

Femoral graft placement is an important factor in the success of anterior cruciate ligament (ACL) reconstruction. In addition to improving the accuracy of femoral tunnel placement, Computer Assisted Surgery (CAS) can be used to determine the anatomic location. This is achieved by using a 3D femoral template which indicates the position of the anatomical ACL center based on endoscopically measurable landmarks. This study describes the development and application of this method. The template is generated through statistical shape analysis of the ACL insertion, with respect to the anteromedial (AM) and posterolateral (PL) bundles. The ligament insertion data, together with the osteocartilage edge on the lateral notch, were mapped onto a cylinder fitted to the intercondylar notch surface (n = 33). Anatomic variation, in terms of standard variation of the positions of the ligament centers in the template, was within 2.2 mm. The resulting template was programmed in a computer-assisted navigation system for ACL replacement and its accuracy and precision were determined on 31 femora. It was found that with the navigation system the AM and PL tunnels could be positioned with an accuracy of 2.5 mm relative to the anatomic insertion centers; the precision was 2.4 mm. This system consists of a template that can easily be implemented in 3D computer navigation software. Requiring no preoperative images and planning, the system provides adequate accuracy and precision to position the entrance of the femoral tunnels for anatomical single- or double-bundle ACL reconstruction.

The safe zone for TransFix fixation in anterior cruciate ligament reconstruction using the anteromedial portal technique

PURPOSE

The risk of neurovascular injury is inherent to cross-pin femoral fixation for anterior cruciate ligament reconstruction and has not been evaluated using the anteromedial portal technique; therefore, we determined a safe zone of cross-pin drill angles.

METHODS

Five cadaveric midthigh to midknee specimens underwent anterior cruciate ligament reconstruction by use of the anteromedial portal to drill the femoral tunnel and a cross-pin femoral fixation system. Guide pins were passed through the femur at -40°, -20°, 0°, and +20°, with 0° being the coronal plane bisecting the femoral shaft, negative angles when the guide pin started posteriorly, and positive angles when the guide pin started anteriorly. Distances between the guide pin and saphenous nerve, femoral artery, and peroneal nerve were measured. The neurovascular structures were considered safe if the guide pin did not pass within 10 mm of the structures.

RESULTS

The mean distance from pin to saphenous nerve was 74, 61, 21, and 24 mm at -40°, -20°, 0°, and +20°, respectively; pin to femoral artery was 100, 85, 59, and 51 mm, respectively; and pin to peroneal nerve was 40, 50, 65, and 76 mm, respectively. The safe zone for the saphenous nerve was violated at 0° and +20° in 2 of 5 knees, and the safe zone for the femoral artery was violated at +20° in 2 of 5 knees.

CONCLUSIONS

We have shown that a 20° safe zone of rotational angles about the axis of the femoral tunnel, from -40° to -20°, minimizes the risk of damage to the saphenous nerve, femoral artery, and peroneal nerve.

CLINICAL RELEVANCE

Intraoperative guide-pin angle measurement can be made in reference to the coronal plane of the femur to guide safe drilling of the TransFix guide pin (Arthrex, Naples, FL).

Femoral cross-pin safety in anterior cruciate ligament reconstruction as a function of femoral tunnel position and insertion angle

PURPOSE

To compare femoral cross-pin guidewire insertion at differing angles to identify "safe zones" relative to saphenous nerve, popliteus tendon, fibular collateral ligament, peroneal nerve, and femoral artery/vein locations between transtibial and medial-portal femoral tunnel drilling methods.

METHODS

Five paired cadaveric knees were randomly assigned to a transtibial or medial-portal femoral (anatomic) tunnel drilling group. Guidewires were inserted at differing frontal plane angles (+10°, 0°, -10°, and -20°). Distances between the guidewire and the anatomic structure of interest were measured with an electronic caliper.

RESULTS

Two-way analysis of variance showed that guidewire angle, not tunnel drilling method, created significant differences between guidewire-saphenous nerve (P < .001) and guidewire-femoral artery/vein (P < .001) distances. The +10° angle showed a shorter guidewire-saphenous nerve distance than the 0°, -10°, and -20° angles. The +10° angle also showed a shorter guidewire-femoral artery/vein distance than the -10° and -20° angles, and the 0° insertion angle created a shorter guidewire-femoral artery/vein distance than the -10° and -20° angles. Fisher exact tests showed that guidewires inserted at a +10° angle showed a greater incidence of safe-zone violations for the saphenous nerve (P = .04) and femoral artery/vein (P < .0001).

CONCLUSIONS

Insertion angle, not tunnel drilling method, influenced saphenous nerve and femoral artery/vein injury risk. At the +10° angle, the saphenous nerve and femoral artery/vein are at greater risk for surgically induced injury. Guidewire insertion at -10° or -20° angles should increase concerns about potential popliteus tendon and fibular collateral ligament injury.

CLINICAL RELEVANCE

Insertion angle, not tunnel drilling method, influenced saphenous nerve and femoral artery/vein injury risk.

Effect of femoral tunnel length on the safety of anterior cruciate ligament graft fixation using cross-pin technique: a cadaveric study

BACKGROUND

A more oblique placement of the anterior cruciate ligament (ACL) graft has been related to better control of rotatory knee stability. Femoral fixation with a transverse system might injure its posterolateral structures.

HYPOTHESIS

A cross-pin system, originally developed for transtibial reconstruction of the ACL, can safely be used when creating a lower femoral tunnel through the anteromedial portal. However, a long femoral tunnel must be created to protect the posterolateral structures of the knee.

STUDY DESIGN

Controlled laboratory study.

METHODS

An ACL was arthroscopically reconstructed with a hamstring graft in 22 fresh cadaveric knees. The femoral tunnel was anatomically drilled in all cases. Knee flexion angle was set at 110 degrees . Femoral fixation was performed with a cross-pin system. A 30-mm-long femoral tunnel was created in 11 knees (group A). In the remaining 11 knees, the femoral tunnel was drilled as long as each lateral condyle permitted (group B). For both groups, the relationships were compared between the cross-pin and the lateral collateral ligament (LCL), popliteus tendon, articular cartilage, and peroneal nerve.

RESULTS

In 5 cases of group A, the cross-pin was placed either through the LCL or between the LCL and popliteus tendon, whereas in group B it was always posterior to the LCL (P = .035). The cross-pin was closer to the articular cartilage in group A than in group B (7.14 mm versus 16.9 mm; P < .001). The minimal distance to the peroneal nerve in all specimens was 23.89 mm.

CONCLUSION

Hamstring graft fixation with a cross-pin system from the anteromedial portal with a 30-mm femoral tunnel presents a higher risk of injury to the LCL. The femoral tunnel should be drilled as long as possible.

CLINICAL RELEVANCE

A long femoral tunnel is required for safe transverse femoral fixation in an anatomical ACL reconstruction.

Placement of femoral tunnel between the AM and PL bundles using a transtibial technique in single-bundle ACL reconstruction

Two different approaches for drilling the femoral tunnel are commonly used in single-bundle anterior cruciate ligament (ACL) reconstruction: creating the femoral tunnel through the tibial tunnel or drilling the tunnel through a low anteromedial arthroscopy portal. When using a transtibial drilling technique, the location of the femoral tunnel is restricted by the angulation of the tibial tunnel in the coronal plane and may lead to a high placement of the femoral tunnel in the intercondylar notch. However, some authors refer that the femoral tunnel can be positioned correctly in the center of the femoral ACL footprint by means of a transtibial technique if the tibial tunnel forms an angle between 60 degrees and 65 degrees to the medial joint line of the tibia in the coronal plane. The purpose of this study was to evaluate prospectively with CT scans whether a femoral tunnel drilled through a tibial tunnel at an angle of 60 degrees-65 degrees in the coronal plane is created between the AM and PL bundles in the lateral femoral condyle. Our results showed that the median difference of the distance between the center of the femoral tunnel and the center of the AM and PL bundles along the Blumensaat's line was 6 and 5%, respectively. In the height of the femoral condyle, the median difference of the distance between the center of the femoral tunnel and the center of the AM and PL bundles was 0 and 31%, respectively. In conclusion, when drilling the femoral tunnel via a transtibial technique with the tibial tunnel angled 60 degrees-65 degrees in the coronal plane, the center of the femoral tunnel is created in the AM bundle footprint in the height of the femoral condyle.

Anatomic single-bundle anterior cruciate ligament reconstruction from the anteromedial portal: evaluation of transverse femoral fixation in a cadaveric model

PURPOSE

The purpose of this study was to assess the risk of injury to the posterolateral structures of the knee when performing anterior cruciate ligament reconstruction from the anteromedial portal while fixing the graft with a femoral cross-pin system.

METHODS

The anterior cruciate ligament was reconstructed arthroscopically with hamstring graft in 10 fresh cadaveric knees. Femoral fixation was performed with a cross-pin system. This was originally developed for a transtibial drilling technique. A femoral tunnel measuring 30 mm in length was drilled through the anteromedial portal in each knee. The knee flexion angle was set at 110 degrees . Lateral dissection was then performed to measure the distances from the cross-pin system to the lateral collateral ligament, the popliteus tendon, the lateral gastrocnemius tendon, and the peroneal nerve.

RESULTS

The lateral collateral ligament was partially torn by the pin in 1 case. In 8 cases the distance to the lateral collateral ligament was shorter than 3 mm (range, 0 to 2.43 mm). In 7 specimens, the cross-pin system was within 4.5 mm of the popliteus tendon. The lateral gastrocnemius tendon was pierced by the cross-pin device in 2 cases. The minimal distance to the peroneal nerve was 23.89 mm.

CONCLUSIONS

Fixation of a hamstring graft with a cross-pin system initially developed for an upper femoral tunnel, following the aforementioned technique, presents the possibility of a high risk of injury to the lateral collateral ligament. The popliteus tendon and the lateral gastrocnemius tendon may also be injured.

CLINICAL RELEVANCE

The risk of injury to the lateral stabilizers of the knee suggests discarding the technique used in this study.

Incidence of the remnant femoral attachment of the ruptured ACL

The presence of remnant tibial and femoral attachments of the ruptured ACL has been described in the literature but the femoral remnant has not been well described as a landmark for tunnel placement during reconstruction. We reviewed operative reports, pictures, and videotapes from 111 ACL reconstructions to determine the incidence of a remnant femoral stump. Patients were divided into two groups: Group A included patients treated from January 2006 through September 2006 (n = 63) when the presence of the femoral footprint was documented retrospectively and Group B included patients treated from September 2006 through June 2007 (n = 48) when the presence or absence of the femoral footprint was documented prospectively. In Group A, there were 48 of 58 (83%) patients with a visible stump and 10 (17%) patients in whom we could not verify the existence of the stump. In Group B, 43 of 44 (98%) patients had a visible stump on the lateral femoral wall that was adequate as a guide for femoral tunnel placement. The native femoral footprint is seen in most cases of ACL reconstruction and can be used for guidance during femoral tunnel preparation.

Differences in graft orientation using the transtibial and anteromedial portal technique in anterior cruciate ligament reconstruction: a magnetic resonance imaging study

The purpose of this study was to evaluate differences in graft orientation between transtibial (TT) and anteromedial (AM) portal technique using magnetic resonance imaging (MRI) in anterior cruciate ligament (ACL) reconstruction. Fifty-six patients who were undergoing ACL reconstruction underwent MRI of their healthy and reconstructed knee. Thirty patients had ACL reconstruction using the TT (group A), while in the remaining 26 the AM (group B) was used. In the femoral part graft orientation was evaluated in the coronal plane using the femoral graft angle (FGA). The FGA was defined as the angle between the axis of the femoral tunnel and the joint line. In the tibial part graft orientation was evaluated in the sagittal plane using the tibial graft angle (TGA). The TGA was defined as the angle between the axis of the tibial tunnel and a line perpendicular to the long axis of the tibia. The ACL angle of the normal knee in the sagittal view was also calculated. The mean FGA for group A was 72 degrees, while for the group B was 53 degrees and this was statistically significant (P < 0.001). The mean TGA for group A was 64 degrees, while for the group B was 63 degrees (P = 0.256). The mean intact ACL angle for group A was 52 degrees, while for the group B was 51 degrees. The difference between TGA and intact ACL angle was statistically significant (P < 0.001) for both groups. Using the AM portal technique, the ACL graft is placed in a more oblique direction in comparison with the TT technique in the femoral part. However, there are no differences between the two techniques in graft orientation in the tibial part. Normal sagittal obliquity is not restored with both techniques.

Femoral guide breakage during the anteromedial portal technique used for ACL reconstruction

Positioning of the femoral tunnel is very important in ACL reconstruction and it is often recommended to use an anteromedial portal technique in order to create the tunnel. This technique is more demanding but it gives a surgeon more freedom to place the ACL graft in an anatomical position compared to the transtibial technique. A case of an intraarticular femoral guide breakage associated with this particular technique is presented. That being said, the aim of this paper is not only to present this rare complication following arthroscopic reconstruction of ACL, but also to indicate how to prevent, diagnose and treat this undesired event.

Femoral bone tunnel placement using the transtibial tunnel or the anteromedial portal in ACL reconstruction: a radiographic evaluation

Correct placement of the tibial and femoral bone tunnel is prerequisite to a successful anterior cruciate ligament (ACL) reconstruction. This study compares the resulting radiographic femoral bone tunnel position of two commonly used techniques for arthroscopically assisted drilling of the femoral bone tunnel: the transtibial approach or drilling through the anteromedial arthroscopy portal. The resulting bone tunnel position was assessed in postoperative knee radiographs of 70 patients after ACL reconstruction. Three independent observers identified the femoral bone tunnel and determined its position in the lateral and A-P view. Differences in femoral tunnel position between transtibial and anteromedial drilling were evaluated. In the sagittal plane, significantly more femoral bone tunnels were positioned close to the reference value using an anteromedial drilling technique (86%) when compared to transtibial drilling (57%). Drilling through the transtibial tunnel resulted in a significantly more anterior position of the femoral tunnel. In the frontal plane, femoral bone tunnels which were placed through the anteromedial arthroscopy portal displayed a significantly greater angulation towards the lateral condylar cortex (50.92 degrees ) when compared to transtibial drilling (58.82 degrees ). In conclusion, drilling the femoral tunnel through the anteromedial arthroscopy portal results in a radiographic femoral bone tunnel position which is suggested to allow stabilization of both anterior tibial translation and rotational instability when using a single bundle reconstruction technique. Further studies may evaluate if there are any clinical advantages using the anteromedial portal technique.

ACL reconstruction: Can the transtibial technique achieve optimal tunnel positioning? A radiographic study

Placement of the femoral tunnel performing ACL reconstruction can be performed using a transtibial technique. Theoretically, this procedure bears the risk of a vertical placement of the femoral tunnel in the intercondylar notch. We assessed tunnel positioning radiographically using the transtibial technique. Postoperative anteroposterior and lateral knee radiographs in 30 patients/knees (19 men, 11 women) undergoing ACL reconstruction using a 4-strand single bundle hamstrings tendon graft by a single surgeon, using a standardized technique, were retrospectively evaluated. Mean age at the time of operation was 27 years (range 16-42). Two experienced independent orthopaedic fellows, not having participated in the management of those patients, performed the radiographic measurements. Mean graft inclination angle was 19 degrees (SD 2). In the sagittal plane the femoral tunnel was placed at 85% (SD 4), posteriorly across Blumensaat's line and the tibial tunnel at 43% (SD 3). Intraobserver Spearman-Brown coefficient was 0.78 and the intraclass correlation was 0.70 (substantial agreement). The values presented are consistent with optimal tunnel positioning according to anatomic and clinical studies. Standardized surgical technique and anatomical landmarks can achieve optimal tunnel positioning using the transtibial technique for ACL reconstruction.

ACL reconstruction using the Rigidfix femoral fixation device via the anteromedial portal: a cadaver study to evaluate chondral injuries

The aim of this anatomic descriptive cadaver study is to evaluate the entrance points of cross-pins and the possible chondral damages, using a two cross-pin femoral fixation device via anteromedial portal, during anterior cruciate ligament (ACL) reconstruction. Twenty fresh-frozen cadaver knees (12 cadavers) were tested. We employed the Rigidfix Cross Pin device (Mitek, Norwood, MA), designed to use two biodegradable pins (PLA, length 42 mm, diameter 2.7 mm). Instead of PLA pins, we used color coded metallic pins. Femoral tunnel drilling and cross-pin guide insertions were performed through the anteromedial portal. We gave three positions to the cross-pin guide: 0 degrees , 45 degrees and 90 degrees slope, referring to the horizontal plane. Per each position, we inserted two metallic pins. We recorded and subdivided the pin holes, in three different groups: Group A (0 degrees ); B (45 degrees ); C (90 degrees of slope). Then a wide dissection has been implemented. Group A: 6 knees (30%) had two pins inside the cartilage of the lateral femoral condyle; 10 knees (50%) had one pin inside the cartilage; and 4 knees (20%) had both pins out of the cartilage. Group B: 7 knees (35%) had two pins inside the cartilage; 12 knees (60%) had one pin inside the cartilage; and one knee (5%) had both pins out of the cartilage. Group C: 7 knees (35%) had two pins inside the cartilage; and 13 knees (65%) had one pin inside the cartilage. The risk of chondral injury, using this technique, is high: from 80% (group A) to 100% (Group C) to have at least one pin inside the cartilage. The use of Rigidfix via AM portal is not recommended for routine ACL reconstruction.

Peripheral versus aperture fixation for anterior cruciate ligament reconstruction

Because both the young and aging population are showing increasing interest in sports participation, the number of sports related injuries and in particular anterior cruciate ligament (ACL) injuries have been increasing. Because of these injuries much time and energy has been focused on ACL reconstruction in order to return these individuals to their optimal level of participation in their sport. This article explores and reviews the concepts of ACL fixation location and how this affects the ultimate outcome of this reconstructive procedure.

Primary versus single-stage revision anterior cruciate ligament reconstruction using autologous hamstring tendon grafts: a prospective matched-group analysis

BACKGROUND

There is a low level of evidence about clinical results after anterior cruciate ligament (ACL) revision reconstruction using autologous hamstring tendon grafts.

HYPOTHESIS

Anterior cruciate ligament revision reconstruction improves knee stability but shows inferior results for functional and subjective outcome and knee stability compared with primary reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Between October 1997 and July 2005, 166 single-stage or 2-stage revision ACL reconstructions were done using different graft types. One hundred twenty-four cases underwent a single-stage revision reconstruction with autologous hamstring tendon grafts. At the time of data analysis, 67 cases fulfilled the criteria of minimum 2-year follow-up. Five patients were lost to follow-up (follow-up rate, 91%). Four patients (6%) who experienced graft rupture were counted as failures but not subjected to further detailed analysis. Because of loss to follow-up and exclusion criteria (n = 12), 50 patients were included in the study. For a comparative matched-group analysis, patients with a primary hamstring tendon graft ACL reconstruction were selected out of a database with minimum 2 years' follow-up (N = 284). Patients were followed using the International Knee Documentation Committee (IKDC) and Lysholm scores, KT-1000 arthrometer testing, and additional functional tests.

RESULTS

Four of 62 available patients (6.5%) in the revision group experienced graft failure, which was comparable to 16 of 284 (5.6%) in the primary reconstruction group. When the 2 matched groups of 50 patients were further compared, postoperative IKDC results showed no significant differences between groups. The manual maximum KT-1000 arthrometer side-to-side difference was 2.1 +/- 1.6 mm for the revision group and 2.2 +/- 1.1 mm for the primary reconstruction group. The Lysholm score was significantly better in the primary reconstruction group (P = .014). The incidence of postoperative positive pivot-shift test results was not significantly different. The primary reconstruction group showed significantly less extension deficits. Functional testing revealed significantly better results for the primary reconstruction group for stair climbing, squatting, knee bending, and duck walk.

CONCLUSIONS

In our patient series, primary ACL reconstruction showed significantly better results in Lysholm score, although the IKDC score and objective knee stability showed no significant difference between the groups. Thus, parameters other than measurable knee stability must be responsible for the inferior results of the revision reconstruction group.

The mid- to long-term results of the anterior cruciate ligament reconstruction with hamstring tendons using Transfix technique

In this study, mid to long-term results of anterior cruciate ligament reconstruction with hamstring tendons and Transfix technique were evaluated. Anterior cruciate ligament (ACL) reconstruction with four-strand hamstring tendon was performed with Transfix technique on 271 (198 males, 73 females; mean age 25.7; 17-52) patients with anterior cruciate ligament ruptures. The patients were followed up with clinical examination, Lysholm and Tegner activity scales, IKDC scoring system, KT-1000 test and radiological examination. The mean follow-up period was 82 (48-100) months; 204 (75%) patients had no subjective complaints. According to the KT-1000 test, only 14 (5%) patients had more than 5 mm laxity postoperatively, whereas, 161 (59%) patients had more than 5 mm laxity preoperatively. In addition to this, only 19 (7%) patients had Lysholm scores less than 80 postoperatively, whereas 154 (57%) patients scored less than 80 preoperatively. When compared with Tegner activity scale, 189 (70%) patients scored<6 preoperatively and only 24 (8%) postoperatively; 78 (29%) patients scored D preoperatively and only 5 (2%) patients scored D postoperatively on the basis of the IKDC scoring system. Our functional results were found to be satisfactory in more than 90% of patients. Commonly seen problems in ACL reconstruction such as inaccurate graft placement and tunnel widening were found to be consistent with the values in relevant literature. However, we demonstrated that the functional results and the stability of the knee were not related with tunnel widening. This study concludes that the reconstruction of ACL with hamstring tendons and the Transfix technique is reasonably successful, safe and causes low morbidity. Furthermore, we believe that proper graft preparation, accurate tunnel placement, notch-plasty, fixation and rehabilitation program are all as important as the choice of graft and fixation material.