Anteromedial portal versus transtibial drilling techniques in anterior cruciate ligament reconstruction: any clinical relevance? A retrospective comparative study

Outcome of Single-Bundle Hamstring Anterior Cruciate Ligament Reconstruction Using the Anteromedial Versus the Transtibial Technique: A Systematic Review and Meta-analysis

PURPOSE

To compare the clinical outcomes of single-bundle hamstring anterior cruciate ligament (ACL) reconstruction between the anteromedial (AM) and transtibial (TT) techniques.

METHODS

We performed a comprehensive systematic review and meta-analysis of the English-language literature in the PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases for articles that compared clinical outcomes of AM versus TT ACL reconstruction. The outcome measures analyzed included postoperative Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC), and Lysholm scores.

RESULTS

We included 10 articles from an initial 308 abstracts for the systematic review and included 6 studies for the meta-analysis. The study population consisted of a total of 733 patients, of whom 366 (49.9%) underwent the AM technique and 367 (50.1%) underwent the TT technique for ACL reconstruction. For postoperative knee stability, the AM technique yielded superior results in terms of the proportion of negative Lachman test results (n = 243; odds ratio [OR], 2.98 [95% confidence interval (CI), 1.29 to 6.88]) and proportion of negative pivot-shift test results (n = 238; OR, 3.67 [95% CI, 1.80 to 7.52]). For postoperative functional status, the AM technique yielded superior results in terms of objective IKDC grading (proportion with IKDC grade A) (n = 269; OR, 2.19 [95% CI, 1.23 to 3.88]) but had comparable Lysholm scores (n = 478; mean difference, 1.43 [95% CI, 0.01 to 2.84]).

CONCLUSIONS

Single-bundle hamstring ACL reconstruction using the AM technique showed superior surgeon-recorded stability according to the IKDC knee score, Lachman test, and pivot-shift test. However, there was no difference in patient-reported functional outcome (Lysholm score).

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis of Level I, II, and III studies.

Femoral and tibial graft tunnel parameters after transtibial, anteromedial portal, and outside-in single-bundle anterior cruciate ligament reconstruction

BACKGROUND

Anatomic graft tunnel placement is recommended in anterior cruciate ligament (ACL) reconstruction to restore knee joint stability and function. Transtibial (TT), anteromedial portal (AMP), and outside-in (OI) retrograde drilling surgical techniques have been described for tibial and femoral bone tunnel preparation.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate the bone tunnel parameters and compare the ability of 3 different surgical techniques to achieve placement of the ACL femoral and tibial bone tunnels at the center of the native ACL femoral and tibial attachment sites. The hypothesis was that tunnel placement using an AMP or OI technique would result in optimized tunnel parameters and more closely reconstruct the center of the native ACL femoral attachment site.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study population consisted of 100 patients undergoing anatomic single-bundle ACL reconstruction using multiple-stranded hamstring tendon grafts. In group 1 (n = 36), the femoral tunnel was drilled using a TT surgical technique; in group 2 (n = 32), the femoral tunnel was drilled through an AMP; and in group 3 (n = 32), the femoral tunnel was created by use of an OI technique with retrograde drilling. Computed tomography (CT) scans were obtained postoperatively, and characteristics of femoral and tibial tunnel apertures were correlated to femoral and tibial measurement grid systems. The position of the resulting tibial and femoral bone tunnels for each group was compared with the center of the native ACL attachment sites.

RESULTS

There were statistically significant differences (P < .05) for the ACL femoral tunnel between the 3 groups with respect to intercondylar height, total tunnel length, graft fixation length, tunnel axis, and tunnel entry angle. Statistically significant differences (P < .05) were found for the ACL tibial tunnel with respect to anteroposterior tunnel position and sagittal tunnel axis between the TT and both the OI and AMP techniques. The OI surgical technique produced more oblique and anatomically correct femoral tunnel apertures and longer femoral tunnel lengths compared with the AMP technique. Both AMP and OI techniques resulted in a more precise replication of intercondylar tunnel depth and height. There was no statistically significant difference for graft fixation length between the AMP and OI techniques.

CONCLUSION

The AMP and OI surgical techniques were superior in positioning the ACL femoral tunnel at the center of the native ACL attachment site compared with the TT technique. An acceptable graft fixation length was obtained for all 3 surgical techniques.

Anterior Cruciate Ligament Reconstruction Using a Flexible Reamer System: Technique and Pitfalls

Anatomic reconstruction of the anterior cruciate ligament (ACL) has been shown to improve stability of the knee, particularly rotational stability, potentially leading to superior clinical outcomes and a shorter return to sport. Nonanatomic ACL reconstruction has been linked to graft failure and abnormal cartilage loading thought to contribute to progression of degenerative joint disease. Use of the far anteromedial portal (FAMP) to uncouple the tibial and femoral tunnels has led to improved reproduction of the femoral footprint and facilitates drilling of the femoral tunnel in an anatomic position. The use of the FAMP and straight reamer systems introduces its own set of potential complications, including short femoral tunnels and peroneal nerve injury. These potential complications have been addressed by drilling the femoral tunnel in a hyperflexed position, which can lead to difficulty with positioning the operative extremity, visualization, and identification of anatomic landmarks. The purpose of this case report was to review the advantages and technical aspects of using a flexible reamer system and the FAMP to achieve an anatomic ACL reconstruction while avoiding potential complications and pitfalls. Flexible reamer systems allow an additional way of uncoupling the tibial and femoral tunnels to clearly visualize and establish an anatomic starting point within the femoral footprint of the native ACL while avoiding the complications associated with knee hyperflexion and straight reamers with the far anteromedial portal. In the authors’ experience, an anatomic reconstruction of the ACL can be achieved safely using flexible reamers while avoiding some of the difficulties seen with straight reamers used in conjunction with an uncoupled, far anteromedial approach.

Advantages and Disadvantages of Transtibial, Anteromedial Portal, and Outside-In Femoral Tunnel Drilling in Single-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

Controversy exists regarding the best method for creating the knee anterior cruciate ligament (ACL) femoral tunnel or socket. The purpose of this study was to systematically review the risks, benefits, advantages, and disadvantages of the endoscopic transtibial (TT) technique, anteromedial portal technique, outside-in technique, and outside-in retrograde drilling technique for creating the ACL femoral tunnel.

METHODS

A PubMed search of English-language studies published between January 1, 2000, and February 17, 2014, was performed using the following keywords: "anterior cruciate ligament" AND "femoral tunnel." Included were studies reporting risks, benefits, advantages, and/or disadvantages of any ACL femoral technique. In addition, references of included articles were reviewed to identify potential studies missed in the original search.

RESULTS

A total of 27 articles were identified through the search. TT technique advantages include familiarity and proven long-term outcomes; disadvantages include the risk of nonanatomic placement because of constrained (TT) drilling. Anteromedial portal technique advantages include unconstrained anatomic placement; disadvantages include technical challenges, short tunnels or sockets, and posterior-wall blowout. Outside-in technique advantages include unconstrained anatomic placement; disadvantages include the need for 2 incisions. Retrograde drilling technique advantages include unconstrained anatomic placement, as well as all-epiphyseal drilling in skeletally immature patients; disadvantages include the need for fluoroscopy for all-epiphyseal drilling.

CONCLUSIONS

There is no one, single, established "gold-standard" technique for creation of the ACL femoral socket. Four accepted techniques show diverse and subjective advantages, disadvantages, risks, and benefits.

LEVEL OF EVIDENCE

Level V, systematic review of Level II through V evidence.

Review of evolution of tunnel position in anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established.

Modified transtibial versus anteromedial portal technique in anatomic single-bundle anterior cruciate ligament reconstruction: comparison of femoral tunnel position and clinical results

BACKGROUND

Although several studies have compared a conventional transtibial technique with an anteromedial (AM) portal technique for single-bundle (SB) anterior cruciate ligament (ACL) reconstruction, no study to date has investigated whether the modified transtibial technique results in the femoral tunnel being in a similar anatomic position and produces similar clinical outcomes with those of the AM portal technique.

PURPOSE

To compare the clinical outcomes and femoral tunnel position of SB ACL reconstruction using a modified transtibial technique (creating a femoral tunnel with varus and internal rotation of the tibia as well as modification of the tibial tunnel orientation) with those of SB ACL reconstruction using an AM portal technique.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 40 patients (40 knees) who underwent arthroscopic SB ACL reconstruction were included in this study. Patients were randomized using a computer-generated sequence into 2 groups: 20 patients by the modified transtibial technique (group 1) and 20 patients by the AM portal technique (group 2). Clinical evaluations included the 2000 International Knee Documentation Committee (IKDC) subjective knee score, Lysholm knee score, Tegner activity scale, Lachman test, pivot-shift test, 2000 IKDC knee examination, and KT-1000 arthrometer measurement. Three-dimensional computed tomography scans were analyzed according to the quadrant method, and the obliquity of the femoral tunnels in the coronal and sagittal planes and the size of the tunnel orifice were measured.

RESULTS

All clinical parameters improved significantly after SB ACL reconstruction, with no between-group differences. The mean distance of the femoral tunnel center location from the posterior condylar surface (0.8% difference; P = .167) and from the Blumensaat line (2.1% difference; P = .067) was similar in groups 1 and 2. The mean coronal obliquity of the femoral tunnel was significantly lower in group 1 than in group 2 (42.5° ± 6.1° vs 49.3° ± 7.2°, respectively; P = .001), but the mean sagittal obliquity was similar between the 2 groups (41.9° ± 6.1° vs 43.3° ± 5.4°, respectively; P = .303). The mean area of the tunnel orifice was significantly greater in group 1 than in group 2 (11.6 ± 1.4 × 9.2 ± 1.6 mm vs 10.3 ± 1.1 × 9.1 ± 1.4 mm, respectively; P = .013).

CONCLUSION

The modified transtibial technique for SB ACL reconstruction showed good clinical results and anatomic placement of the femoral tunnel, similar with those of the AM portal technique.

The relation between knee flexion angle and anterior cruciate ligament femoral tunnel characteristics: a cadaveric study comparing a standard and a far anteromedial portal

PURPOSE

The purpose of this study was to compare the anterior cruciate ligament (ACL) femoral tunnel characteristics between 2 common arthroscopic portals used for ACL reconstruction, a standard anteromedial portal and a far anteromedial portal.

METHODS

Seven cadaveric knees were used. A 1.25-mm Kirschner wire was drilled through the center of the ACL femoral footprint and through the distal femur from the standard anteromedial and far anteromedial portals at knee flexion angles of 100°, 120°, and 140°. No formal tunnels were drilled. Each tunnel exit point was marked with a colored pin. After all tunnels were created, the specimens were digitized with a MicroScribe device (Revware, Raleigh, NC) to measure the tunnel length; distance to the posterior femoral cortical wall (posterior cortical margin); and tunnel orientation in the sagittal, coronal, and axial planes.

RESULTS

The standard anteromedial portal resulted in a longer tunnel length, a less horizontal tunnel in the coronal plane, and a greater posterior cortical margin compared with the far anteromedial portal at all knee flexion angles. For both portal locations, the tunnel length and posterior cortical margin increased, and the tunnel position became more horizontal in the coronal plane, more anterior in the sagittal plane, and less horizontal in the transverse plane as knee flexion increased.

CONCLUSIONS

Portal position affects femoral tunnel characteristics, with results favoring the more laterally positioned standard anteromedial portal at all flexion angles. Increasing the knee flexion angle leads to a longer femoral tunnel length and posterior femoral cortical margin with either portal position.

CLINICAL RELEVANCE

Understanding how portal positioning and knee flexion angle affect femoral tunnel orientation and characteristics may lead to improved surgical outcomes after ACL reconstruction.

A comparison of the anteromedial and transtibial drilling technique in ACL reconstruction after a short-term follow-up

INTRODUCTION

The purpose of this study was to compare clinical and radiological outcomes of patients who underwent single-bundle anterior cruciate ligament (ACL) reconstruction with anteromedial portal (AMP) and transtibial (TT) techniques.

MATERIALS AND METHODS

Arthroscopic single-bundle ACL reconstruction was performed using AMP technique in 34 patients and TT technique in 30 patients. The patients were evaluated retrospectively. Aperture fixation was used for femoral fixation, and absorbable screws and U staples were used for tibial fixation of the graft. Pivot shift test, Lachman test, Lysholm, Tegner, and International Knee Documentation Committee (IKDC-2000) scoring systems were used in the clinical and functional evaluation of patients before and after the surgery. Time to return sports and activity level were assessed. In the radiological evaluation of non-anatomic bone tunnel placement, the criteria developed by lllingworth et al. were used. The mean duration of follow-up was 20.4 and 24.6 months in the AMP and TT groups, respectively.

RESULTS

There was a significant difference between the AMP group (86.7 %) and the TT (14.7 %) group in terms of anatomical placement of the femoral tunnels and grafts (p < 0.001). No significant difference was observed between the two groups in terms of the Pivot shift test, Lachman test, Lysholm, Tegner, and IKDC scores, and activity level (p > 0.05). The patients in the AMP group returned to sports 1.5 months earlier on average (p < 0.001).

CONCLUSIONS

It was shown that AMP technique was superior to the TT technique in providing anatomical placement of the graft and in recovery time to return sports; however, there was no difference between groups in early periods in terms of the clinical and functional outcomes.

Anterior cruciate ligament reconstruction practice patterns by NFL and NCAA football team physicians

PURPOSE

This study aimed to determine practice patterns for National Football League (NFL) and National Collegiate Athletic Association (NCAA) Division I football team orthopaedic surgeons regarding management of anterior cruciate ligament (ACL) tears in elite, young, and middle-aged recreational athletes.

METHODS

Two hundred sixty-seven NFL and NCAA Division I team orthopaedic surgeons were surveyed through an online survey. A 9-question survey assessed surgeon experience, graft choice, femoral tunnel drilling access, number of graft bundles, and rehabilitation after ACL reconstruction.

RESULTS

One hundred thirty-seven team orthopaedic surgeons (51%) responded (mean experience 16.75 ± 8.7 years). Surgeons performed 82 ± 50 ACL reconstructions in 2012. One hundred eighteen surgeons (86%) would use bone-patellar tendon-bone (BPTB) autografts to treat their starting running backs. Ninety (67%) surgeons drill the femoral tunnel through an accessory anteromedial portal (26% through a transtibial portal). Only 1 surgeon prefers a double-bundle to a single-bundle reconstruction. Seventy-seven (55.8%) surgeons recommend waiting at least 6 months before return to sport, whereas 17 (12.3%) wait at least 9 months. No surgeon recommends waiting 12 months or more before return to sport. Eighty-eight (64%) surgeons do not recommend a brace for their starting running backs during sport once they return to play.

CONCLUSIONS

BPTB is the most frequently used graft for ACL reconstruction by NFL and NCAA Division I team physicians in their elite-level running backs. Nearly all surgeons always use a single-bundle technique, and most do not recommend a brace on return to sport in running backs. Return to sport most commonly occurs at least 6 months postoperatively, with some surgeons requiring a normal examination and normal return-to-sport testing (single leg hop).