Tibial tunnel aperture irregularity after drilling with 5 reamer designs: a qualitative micro-computed tomography analysis

Comparison of the Clinical Outcomes between All-inside and Standard Technique in Anterior Cruciate Ligament Reconstruction with 6-strand Hamstring Tendon Autograft

OBJECTIVE

All-inside and standard techniques with 4-strand hamstrings graft have been widely used in anterior cruciate ligament (ACL) reconstruction. However, the graft diameter of less than 8 mm will significantly increase the rate of surgical failure, and the 6-strand graft can solve this problem. The purpose of this study is to compare all-inside ACL reconstruction using suspensory cortical button fixation on both tibia and femur with standard ACL reconstruction using suspensory femoral fixation and a bioabsorbable tibial interference screw with a 6-strand hamstring tendon autograft in postoperative clinical outcomes.

METHODS

From January 2020 to December 2020, 48 patients performed ACL reconstruction were divided into the all-side group and the standard group according to the different surgical techniques. Magnetic resonance imaging (MRI) and subjective function scores was used to assess clinical outcomes at least 24 months following ACL reconstruction. MRI was used to measure the value of bone tunnel widening in articular and middle portions. Subjective function scores included the Lysholm knee score, the International Knee Documentation Committee (IKDC) score, the Knee Society Score (KSS) for pain and function, and KT-1000. The t-test was used assuming the distribution of the patients which follows the normal distribution and we used non-parametric tests if these two conditions were not satisfied.

RESULTS

At the final follow-up, there were 22 patients in the all-inside group and 24 patients in the standard group. No significant differences were found with respect to femoral tunnel widening and subjective function scores. However, a significant increase in tibial tunnel widening was found in the middle portion of the standard group (2.25 ± 0.74) compared to the all-inside group (0.76 ± 0.24) (p < 0.01) and also in the articular portion of the standard group (2.07 ± 0.77) compared to the all-inside group (1.52 ± 0.54) (p = 0.02). In addition, the value of the KT-1000 was 1.81 ± 0.45 for the all-inside group and 2.12 ± 0.44 in the standard group (p = 0.016).

CONCLUSION

The objective stability of the knee was relatively better in the all-inside group than in the standard group. And tunnel widening after ACL reconstruction was significantly greater in the standard technique when compared to the all-inside technique on the tibia side.

A Surgical Technique for Anterior Cruciate Ligament Reconstruction Using Semitendinosus Graft: An All-Inside Transfemoral Approach

Given the paucity of reports on all-inside reconstruction procedures via the transfemoral approach, we describe a minimally invasive, all-inside transfemoral technique that enables creating femoral and tibial sockets from the intra-articular cavity. Our transfemoral approach makes it possible to sequentially create femoral and tibial sockets using the same reamer bit, while a single drilling guide is set in place. Our custom socket drilling guide was designed to integrate with a tibial tunnel guide, which helped locate the tunnel exit at an anatomically acceptable location. The advantages of this method include easy and precise positioning of the femoral tunnel, narrow tibial tunnel, minimal damage to the intramedullary trabecular bone integrity, and low postoperative risks of pain, bleeding, and infections.

Comparison of Acorn and Fluted Reamers on Tibial Tunnel Outer Aperture Dimensions in ACL Reconstruction

The aim of this study was to determine if the type of reamer used in tibial tunnel creation during anterior cruciate ligament (ACL) reconstruction influences the dimensions of the tunnel's outer aperture. Tibial tunnels were created in tibial saw bones by reaming over a guidewire using an 8 mm acorn or fluted reamer in an antegrade manner. Reaming was aimed either in line with the guidewire, or with 10-degree inferior/superior deviation in relation to the wire. The shape and size of the outer aperture of the tibial tunnel were compared between the two reamers. When using the acorn reamer, a 10-degree deviation in relation to the guidewire resulted in minimal change in outer aperture length (mean 13.6 vs. 15.6 mm, p = 0.11) and width (11.6 vs. 11.1 mm, p = 0.51). However, when using the fluted reamer, although the aperture width showed no substantial change with reamer/guidewire deviation (11.4 vs. 11.2 mm, p = 0.71), the mean length almost doubled (14.7 vs. 28.1 mm, p = 0.002). The use of a fluted reamer when reaming the tibial tunnel creates a distal aperture which is inconsistently sized, larger, and of oblong shape compared with an acorn-shaped reamer. This should be taken in consideration when using a fluted reamer for creating the tibial tunnel in ACL reconstruction.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

The Influence of Graft Tensioning Sequence on Tibiofemoral Orientation During Bicruciate and Posterolateral Corner Knee Ligament Reconstruction: A Biomechanical Study

BACKGROUND

During multiple knee ligament reconstructions, the graft tensioning order may influence the final tibiofemoral orientation and corresponding knee kinematics. Nonanatomic tibiofemoral orientation may result in residual knee instability, altered joint loading, and an increased propensity for graft failure.

PURPOSE

To biomechanically evaluate the effect of different graft tensioning sequences on knee tibiofemoral orientation after multiple knee ligament reconstructions in a bicruciate ligament (anterior cruciate ligament [ACL] and posterior cruciate ligament [PCL]) with a posterolateral corner (PLC)-injured knee.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten nonpaired, fresh-frozen human cadaveric knees were utilized for this study. After reconstruction of both cruciate ligaments and the PLC and proximal graft fixation, each knee was randomly assigned to each of 4 graft tensioning order groups: (1) PCL → ACL → PLC, (2) PCL → PLC → ACL, (3) PLC → ACL → PCL, and (4) ACL → PCL → PLC. Tibiofemoral orientation after graft tensioning was measured and compared with the intact state.

RESULTS

Tensioning the ACL first (tensioning order 4) resulted in posterior displacement of the tibia at 0° by 1.7 ± 1.3 mm compared with the intact state ( P = .002). All tensioning orders resulted in significantly increased tibial anterior translation compared with the intact state at higher flexion angles ranging from 2.7 mm to 3.2 mm at 60° and from 3.1 mm to 3.4 mm at 90° for tensioning orders 1 and 2, respectively (all P < .001). There was no significant difference in tibiofemoral orientation in the sagittal plane between the tensioning orders at higher flexion angles. All tensioning orders resulted in increased tibial internal rotation (all P < .001). Tensioning and fixing the PLC first (tensioning order 3) resulted in the most increases in internal rotation of the tibia: 2.4° ± 1.9°, 2.7° ± 1.8°, and 2.0° ± 2.0° at 0°, 30°, and 60°, respectively.

CONCLUSION

None of the tensioning orders restored intact knee tibiofemoral orientation. Tensioning the PLC first should be avoided in bicruciate knee ligament reconstruction with concurrent PLC reconstruction because it significantly increased tibial internal rotation. We recommend that the PCL be tensioned first, followed by the ACL, to avoid posterior translation of the tibia in extension where the knee is primarily loaded during most activities. The PLC should be tensioned last.

CLINICAL RELEVANCE

This study will help guide surgeons in decision making for the graft tensioning order during multiple knee ligament reconstructions.

Anatomic Anterolateral Ligament Reconstruction of the Knee Leads to Overconstraint at Any Fixation Angle

BACKGROUND

Anterior cruciate ligament (ACL) tears are one of the most common injuries among athletes. However, the ability to fully restore rotational stability with ACL reconstruction (ACLR) remains a challenge, as evidenced by the persistence of rotational instability in up to 25% of patients after surgery. Advocacy for reconstruction of the anterolateral ligament (ALL) is rapidly increasing because some biomechanical studies have reported that the ALL is a significant contributor to internal rotational stability of the knee.

HYPOTHESIS/PURPOSE

The purpose of this study was to assess the effect of ALL reconstruction (ALLR) graft fixation angle on knee joint kinematics in the clinically relevant setting of a concomitant ACLR and to determine the optimal ALLR graft fixation angle. It was hypothesized that all fixation angles would significantly reduce rotational laxity compared with the sectioned ALL state.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten nonpaired fresh-frozen human cadaveric knees underwent a full kinematic assessment in each of the following states: (1) intact; (2) anatomic single-bundle (SB) ACLR with intact ALL; (3) anatomic SB ACLR with sectioned ALL; (4) anatomic SB ACLR with 7 anatomic ALLR states using graft fixation angles of 0°, 15°, 30°, 45°, 60°, 75°, and 90°; and (5) sectioned ACL and ALL. Internal rotation during a 5-N·m internal rotation torque and anterior translation during an 88-N anterior load were recorded at 15° flexion intervals between 0° and 120°. Axial plane translation and internal rotation during a simulated pivot-shift test (combined 5-N·m internal rotation and 10-N·m valgus torques) were recorded between 0° and 60°. Kinematic changes were measured and compared with the intact state for all reconstructed and sectioned states.

RESULTS

Anatomic ALLR at all graft fixation angles significantly overconstrained internal rotation of the knee joint beyond 30° of flexion and at 45° and 60° during the pivot-shift test. Furthermore, there were no significant knee kinematic differences between any tested graft fixation angles during anterior drawer, pivot-shift, and internal rotation tests.

CONCLUSION

Anatomic ALLR in conjunction with an ACLR significantly reduced rotatory laxity of the knee beyond 30° of knee flexion. However, ALLR, regardless of fixation angle, resulted in significant overconstraint of the knee.

CLINICAL RELEVANCE

ALLR at any fixation angle overconstrained native joint kinematics and should be performed with careful consideration. Further investigation into the application and target population for ALLR is strongly recommended.

An In Vitro Robotic Assessment of the Anterolateral Ligament, Part 2: Anterolateral Ligament Reconstruction Combined With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Recent biomechanical studies have demonstrated that an extra-articular lateral knee structure, most recently referred to as the anterolateral ligament (ALL), contributes to overall rotational stability of the knee. However, the effect of anatomic ALL reconstruction (ALLR) in the setting of anterior cruciate ligament (ACL) reconstruction (ACLR) has not been biomechanically investigated or validated.

PURPOSE/HYPOTHESIS

The purpose of this study was to investigate the biomechanical function of anatomic ALLR in the setting of a combined ACL and ALL injury. More specifically, this investigation focused on the effect of ALLR on resultant rotatory stability when performed in combination with concomitant ACLR. It was hypothesized that ALLR would significantly reduce internal rotation and axial plane translation laxity during a simulated pivot-shift test compared with isolated ACLR.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten fresh-frozen cadaveric knees were evaluated with a 6 degrees of freedom robotic system. Knee kinematics were evaluated with simulated clinical examinations including a simulated pivot-shift test consisting of coupled 10-N·m valgus and 5-N·m internal rotation torques, a 5-N·m internal rotation torque, and an 88-N anterior tibial load. Kinematic differences between ACLR with an intact ALL, ACLR with ALLR, and ACLR with a deficient ALL were compared with the intact state. Single-bundle ACLR tunnels and ALLR tunnels were placed anatomically according to previous quantitative anatomic attachment descriptions.

RESULTS

Combined anatomic ALLR and ACLR significantly improved the rotatory stability of the knee compared with isolated ACLR in the face of a concurrent ALL deficiency. During a simulated pivot-shift test, ALLR significantly reduced internal rotation and axial plane tibial translation when compared with ACLR with an ALL deficiency. Isolated ACLR for the treatment of a combined ACL and ALL injury was not able to restore stability of the knee, resulting in a significant increase in residual internal rotation laxity. ALLR did not affect anterior tibial translation; no significant differences were observed between the varying ALL conditions with ACLR except between ACLR with an intact ALL and ACLR with a deficient ALL at 0° of flexion.

CONCLUSION

In the face of a combined ACL and ALL deficiency, concurrent ACLR and ALLR significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL.

CLINICAL RELEVANCE

Significant increases in residual internal rotation and laxity during the pivot-shift test may exist in both acute and chronic settings of an ACL deficiency and in patients treated with isolated ACLR for a combined ACL and ALL deficiency. For this subset of patients, surgical treatment of the ALL, in addition to ACLR, should be considered to restore knee stability.

Quantification of tibial bone loss in antegrade versus retrograde tunnel placement for anterior cruciate ligament reconstruction

PURPOSE

Tibial bone destruction during primary graft tunnel placement and tibial bone loss following tunnel enlargement represent major challenges in revision reconstruction of the anterior cruciate ligament (ACL). Initial all-inside ACL reconstruction facilitates the preparation of tibial bone sockets rather than full tunnels that potentially preserve tibial bone stock. The purpose of this study was to comparatively assess length, diameter and volume of tibial graft tunnels following all-inside and conventional ACL reconstruction.

METHODS

Postoperative computed tomography (CT) scans of 59 patients were assessed following ACL reconstruction. In 35 patients we used conventional antegrade tibial tunnel drilling and in 24 all-inside retrograde tibial bone sockets. Imaging analysis included total, minimal and maximal tunnel length and tunnel diameter. Tunnel volumes were calculated corresponding to these parameters.

RESULTS

Statistically significant group differences (p < 0.01) could be detected for tibial tunnel volume, length and diameter between conventional antegrade and all-inside retrograde tibial bone tunnels and sockets, respectively.

CONCLUSIONS

Compared with conventional techniques, all-inside retrograde drilling of tibial bone sockets is effective in preserving significant bone stock, which might be beneficial for revision reconstruction in cases of eventual primary graft failure.

Consequences of tibial tunnel reaming on the meniscal roots during cruciate ligament reconstruction in a cadaveric model, Part 2: The posterior cruciate ligament

BACKGROUND

Recent emphasis has turned to reconstructing the posterior cruciate ligament (PCL) after injury. However, single-bundle PCL reconstruction of the anterolateral bundle may potentially injure the posterior meniscal roots.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine if posterior meniscal root injuries occurred because of tunnel reaming for single-bundle PCL reconstruction. It was hypothesized that tibial tunnel reaming within the anterolateral bundle footprint during PCL reconstruction would result in clinically significant decreases in posteromedial (PM) root attachment areas and in ultimate failure strength for the PM root.

STUDY DESIGN

Controlled laboratory study.

METHODS

Testing was performed on 12 matched pairs of human cadaveric knees. For each pair of knees, one knee was left intact, while the contralateral knee was prepared with a tibial tunnel placed 5 mm anterior to the center of the tibial PCL attachment and within the previously described footprint of the anterolateral bundle of the PCL for single-bundle PCL reconstruction. The attachment areas of the posterior meniscal roots were measured with a coordinate measuring device before and after PCL tunnel reaming. The posterior meniscal roots were then pulled to failure with a dynamic tensile testing machine.

RESULTS

There was a significant mean decrease in the attachment area of the PM root (%Δ, 28%; 95% CI, 16-40) after PCL tunnel reaming compared with the intact state (P=.005). The mean ultimate failure strength of the native PM root (mean, 440 N; 95% CI, 347-534) was also significantly stronger (mean, 40%; 95% CI, 18-61; P=.005) than that of the PM root after PCL tunnel reaming (mean, 243 N; 95% CI, 176-309). No changes were found for the posterolateral (PL) root after PCL tunnel reaming.

CONCLUSION

Tibial tunnel reaming for single-bundle PCL reconstruction in the anterolateral bundle footprint significantly reduced the ultimate failure strength and attachment area of the PM meniscal root. The attachment area and ultimate failure strength of the PL root were unaffected by tunnel reaming.

CLINICAL RELEVANCE

Tibial tunnels reamed in the footprint of the anterolateral bundle during single-bundle PCL reconstruction can cause iatrogenic damage to the PM meniscal root attachment. Thus, tibial tunnels should strive to be reamed in the center of the entire tibial PCL attachment site during PCL reconstruction.

Consequences of tibial tunnel reaming on the meniscal roots during cruciate ligament reconstruction in a cadaveric model, Part 1: The anterior cruciate ligament

BACKGROUND

The current standard for treating complete tears of the anterior cruciate ligament (ACL) is reconstruction, which requires reaming a tibial tunnel. Based on recent anatomic and biomechanical studies, this reconstruction tunnel may cause injuries to the anterior meniscal root attachments.

PURPOSE/HYPOTHESIS

The purpose was to determine if injuries occurred to the anteromedial (AM) and anterolateral (AL) meniscal root attachments because of reaming a tibial reconstruction tunnel in the anatomic center of the ACL footprint. It was hypothesized that tibial tunnel reaming for ACL reconstruction would result in significant decreases in the attachment area and in ultimate failure strength for the AL root.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve matched pairs of human cadaveric knees were tested. One knee from each pair remained intact, while the contralateral knee was reamed with a tibial tunnel for an anatomic ACL reconstruction. The attachment areas of the anterior meniscal roots were measured with a coordinate measuring device before and after tunnel reaming. The anterior meniscal roots were then pulled to failure with a dynamic tensile testing machine.

RESULTS

There was a significant mean decrease in the attachment area for the AL root (%Δ, 38%; 95% CI, 25-51) after ACL tunnel reaming compared with the intact state (P=.003). The mean ultimate failure strength of the native AL root (mean, 610 N; 95% CI, 470-751) was significantly stronger (P=.015) than that of the AL root with a reamed ACL reconstruction tunnel (mean, 506 N; 95% CI, 353-659). Tunnel reaming did not significantly affect the AM root attachment area or ultimate failure strength.

CONCLUSION

Tibial tunnel reaming during anatomic single-bundle ACL reconstruction significantly decreased the AL meniscal root attachment area and ultimate failure strength. The AM root was not significantly affected by reaming of the ACL reconstruction tunnel. Future studies should investigate the clinical importance of these iatrogenic injuries to the AL root.

CLINICAL RELEVANCE

The ACL reconstruction tunnels reamed in the center of the ACL tibial footprint caused a significant decrease in the attachment area and ultimate strength of the AL meniscal root attachment. Clinically, repositioning guide pins placed in the lateral aspect of the ACL attachment before tibial tunnel reaming may minimize iatrogenic injuries to the AL meniscal root attachment.

Anterior talofibular ligament ruptures, part 1: biomechanical comparison of augmented Broström repair techniques with the intact anterior talofibular ligament

BACKGROUND

The concept of utilizing nonabsorbable suture tape fixed directly to bone to augment Broström repairs of the anterior talofibular ligament (ATFL) has been proposed. No biomechanical studies of this technique are available.

HYPOTHESIS

We hypothesized that suture tape augmentation alone and Broström repair with suture tape augmentation would have similar biomechanical properties to the intact ATFL at time zero in a cadaveric model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eighteen fresh-frozen cadaveric ankles were randomized into 3 groups of 6 specimens each: (1) intact ATFL, (2) suture tape augmentation, and (3) Broström repair with suture tape augmentation. The specimens were loaded to failure to determine the strength and stiffness of each construct.

RESULTS

The mean ultimate load to failure of suture tape augmentation (315.5 ± 66.8 N) was significantly higher than that of the intact ATFL (154.0 ± 63.7 N) (P = .017). The mean ultimate load of the Broström repair with suture tape augmentation (250.8 ± 122.7 N) was not significantly different from that of the intact ATFL. The mean stiffness of augmentation alone (31.4 ± 9.9 N/mm) was significantly higher than that of the intact ATFL (14.5 ± 4.4 N/mm) (P = .008). The mean stiffness of the Broström repair with augmentation (21.1 ± 9.1 N/mm) was not significantly different from that of the intact ATFL.

CONCLUSION

The ATFL with suture tape augmentation is at least as strong and stiff as the native ATFL at time zero in a fresh-frozen cadaveric model.

CLINICAL RELEVANCE

The Broström repair for lateral ankle ligament ruptures is often unsuccessful in circumstances of poor tissue quality. Augmentations, such as with suture tape, have been proposed for these situations. Suture tape used alone or in combination with the Broström repair provided increased strength and stiffness compared with the standard Broström repair, which produced an immediate strength of less than 50% of the intact ATFL. Adding strength to the Broström repair may be valuable in patients with generalized ligamentous laxity, in large patients or elite athletes, or when graft reconstruction is not feasible.

Anterior talofibular ligament ruptures, part 2: biomechanical comparison of anterior talofibular ligament reconstruction using semitendinosus allografts with the intact ligament

BACKGROUND

Anatomic reconstructions of the lateral ankle ligaments with grafts have been proposed for patients with generalized ligamentous laxity, long-standing instability with attenuated native tissues, varus hindfoot misalignment, or failed prior lateral ligament surgery and for very large patients or elite athletes because of increased demands.

HYPOTHESIS

Anatomic reconstruction of the anterior talofibular ligament (ATFL) using a semitendinosus allograft fixed with biocomposite interference fit screws would have similar biomechanical properties to the intact ATFL at time zero in a cadaveric model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Allograft reconstruction of the ATFL was performed in 6 fresh-frozen cadaveric ankles. The specimens were loaded to failure to determine the strength and stiffness of the reconstruction and compared with data from 6 cadaveric specimens with intact ATFLs.

RESULTS

The mean ultimate load to failure of the allograft reconstruction (170.7 ± 54.8 N) was not significantly different from that of the intact ATFL (154.0 ± 63.7 N). The mean stiffness of the allograft reconstruction (23.1 ± 9.3 N/mm) was also not significantly different from that of the intact ATFL (14.5 ± 4.4 N/mm).

CONCLUSION

Anatomic reconstruction of the ATFL with allografts demonstrated similar strength and stiffness to the native ligament at time zero in a fresh-frozen cadaveric model.

CLINICAL RELEVANCE

This technique of anatomic reconstruction of the ATFL with allografts has biomechanical validation for use in clinical situations where a Broström repair of the lateral ankle ligaments is unlikely to be successful or has previously failed.

Biomechanical comparison of anatomic single- and double-bundle anterior cruciate ligament reconstructions: an in vitro study

BACKGROUND

Arthroscopic identification of the anteromedial (AM) and posterolateral (PL) bundle locations of the anterior cruciate ligament (ACL) has facilitated an improved quantitative description of ACL anatomy. Few studies have directly compared the biomechanical laxity of anatomic single-bundle (SB) versus anatomic double-bundle (DB) ACL reconstruction techniques based on precise anatomic descriptions.

HYPOTHESIS

Anatomic tunnel positioning for SB and DB reconstructions would produce comparable anterior-posterior and rotatory knee laxity.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine matched pairs of cadaveric knees were evaluated for the kinematics of intact, ACL-deficient, and either anatomic SB or anatomic DB ACL-reconstructed knees. Reconstruction tunnels were placed either centrally in the ACL footprint or within the AM and PL footprints. A 6 degrees of freedom robotic system was used to assess knee laxity with an 88-N anterior tibial load and a simulated pivot-shift test of combined 10-N · m valgus and 5-N · m internal tibial torques. Rotational motion was measured with internal and external torques of 5 N · m along with varus and valgus torques of 10 N · m. One-sample and 2-sample independent t tests were used to compare between groups (P < .05).

RESULTS

No significant differences were found between anatomic SB and DB reconstruction groups during anterior tibial loading. Anterior tibial translations during simulated pivot shift had no significant differences between anatomic reconstruction groups. Tibial rotation for internal/external and varus/valgus torques showed no significant differences between anatomic reconstructions, with the exception of small (<3°) but statistically significant differences in internal rotation at 20° and 30° of flexion. Despite the similar behavior between the 2 anatomic reconstruction groups, neither technique was able to reproduce the intact state during an anterior tibial load.

CONCLUSION

No significant differences in anterior translation were found between the anatomic SB and anatomic DB ACL reconstructions for simulated pivot shift or anterior tibial loading.

CLINICAL RELEVANCE

Although significant differences between reconstructions were observed for internal rotation, the small magnitude of these differences (<3°) may not have clinical significance.