A prospective evaluation of the anterior horn of the lateral meniscus as a landmark for tibial tunnel placement in anterior cruciate ligament (ACL) reconstruction

Management after acute injury of the anterior cruciate ligament (ACL). Part 3: Recommendation on surgical treatment

PURPOSE

The aim of this consensus project was to give recommendations regarding surgical treatment of the anterior cruciate ligament (ACL) injured patient.

METHODS

For this consensus process, an expert, steering and rating group was formed. In an initial online meeting, the steering group, together with the expert group, formed various key topic complexes for which multiple questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement.

RESULTS

During this consensus process, 30 topics regarding the surgical management and technique of ACL reconstruction were identified. The literature search for each key question resulted in 30 final statements. Of these 30 final statements, all achieved consensus.

CONCLUSIONS

This consensus process has shown that surgical treatment of ACL injury is a complex process. Various surgical factors influence patient outcomes. The proposed treatment algorithm can be used as a decision aid for the surgeon.

LEVEL OF EVIDENCE

Level V.

Effect of Patient Height and Sex on the Patellar Tendon and Anterior Cruciate Ligament

Background:

Graft-tunnel mismatch is an avoidable complication in anterior cruciate ligament (ACL) reconstruction. Patient height and sex may be predictors of patellar tendon length (PTL) and intra-articular ACL length (IAL). Understanding these relationships may assist in reducing graft-tunnel mismatch during ACL reconstruction with bone–patellar tendon–bone (BTB) autograft.

Purpose:

To determine the association of patient height and sex with PTL and IAL.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Magnetic resonance imaging (MRI) studies were obtained on the healthy knees of 100 male and 100 female patients. Patients with prior surgery, open physes, significant degenerative changes, ACL rupture, or extensor mechanism injury were excluded. Three independent readers measured PTL, IAL, and Caton-Deschamps Index (CDI) on MRI. Bivariate and linear regression analysis was performed to detect the association of anthropometric data with anatomic parameters measured on MRI studies.

Results:

The mean age and body mass index were not significantly different between the male and female patients; however, male patients were significantly taller than female patients (1.75 vs 1.72 m, respectively; P < .001). There was a substantial agreement between the 3 readers for all parameters (κ > 0.75). Overall, female patients had significantly longer PTL (47.38 vs 43.92 mm), higher CDI (1.146 vs 1.071), and shorter IAL (33.05 vs 34.39 mm) (P < .001 for all). Results of the linear regression analysis demonstrated that both height and female sex were predictive of longer PTL. Further, height was independently predictive of IAL but sex was not.

Conclusion:

PTL was correlated more with patient sex than height. IAL was also correlated with patient sex. Longer BTB grafts are expected to be harvested in female patients compared with male patients of the same height despite shorter IAL. These associations should be considered during BTB ACL reconstruction to minimize graft-tunnel mismatch.

Effect of Tibial Tunnel Placement Using the Lateral Meniscus as a Landmark on Clinical Outcomes of Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

BACKGROUND

It remains unclear if use of the lateral meniscus anterior horn (LMAH) as a landmark will produce consistent tunnel positions in the anteroposterior (AP) distance across the tibial plateau.

PURPOSE

To evaluate the AP location of anterior cruciate ligament (ACL) reconstruction tibial tunnels utilizing the LMAH as an intra-articular landmark and to examine how tunnel placement affects knee stability and clinical outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review was conducted of 98 patients who underwent primary ACL reconstruction with quadrupled hamstring tendon autografts between March 2013 and June 2017. Patients with unilateral ACL injuries and a minimum follow-up of 2 years were included in the study. All guide pins for the tibial tunnel were placed using the posterior border of the LMAH as an intra-articular landmark. Guide pins were evaluated with the Bernard-Hertel grid in the femur and the Stäubli-Rauschning method in the tibia. Patients were divided by the radiographic location of the articular entry point of the guide pin with relation to the anterior 40% of the tibial plateau. Outcomes were evaluated by the Marx Activity Scale and International Knee Documentation Committee (IKDC) form. Anterior knee laxity was evaluated using a KT-1000 arthrometer and graded with the objective portion of the IKDC form. Rotational stability was evaluated using the pivot-shift test.

RESULTS

A total of 60 patients were available for follow-up at a mean 28.6 months. The overall percentage of AP placement of the tibial tunnel was 39.3% ± 3.8% (mean ± SD; range, 31%-47%). Side-to-side difference of anterior knee laxity was significantly lower in the anterior group than the posterior group (1.2 ± 1.1 mm vs 2.5 ± 1.3 mm; P < .001; r = 0.51). The percentage of AP placement of the tibial tunnel demonstrated a positive medium correlation with side-to-side difference of anterior knee laxity as measured by a KT-1000 arthrometer (r = 0.430; P < .001). The anterior group reported significantly better distribution of IKDC grading as compared with the posterior group (26 grade A and 6 grade B vs 15 grade A and 13 grade B; P = .043; V = 0.297). The pivot-shift test results and outcome scores showed no significant differences between the groups.

CONCLUSION

Using the posterior border of the LMAH as an intraoperative landmark yields a wide range of tibial tunnel locations along the tibial plateau, with anterior placement of the tibial tunnel leading toward improved anterior knee stability.

[Arthroscopic anterior cruciate ligament reconstruction via tibial tunnel made by three-portal technique]

Objective

To evaluate the effectiveness of arthroscopic anterior cruciate ligament (ACL) reconstruction via tibial tunnel made by three-portal technique.

Methods

Between July 2015 and December 2016, 45 patients with ACL ruptures were treated. There were 29 males and 16 females with an average age of 27.5 years (range, 18-42 years). There were 18 cases in the left side and 27 cases in the right side. There were 28 cases of sports injuries, 13 cases of traffic accidents, and 4 cases of other injuries. The average time from injury to operation was 21.6 days (range, 5-36 days). There were 25 cases of simple ACL injury and 20 cases of ACL complicated with medial collateral ligament, medial meniscus or lateral meniscus injuries. The Lachman tests of all patients were positive. The pivot shift tests of all patients were positive with grade Ⅰ in 27 cases, grade Ⅱ in 13 cases, and grade Ⅲ in 5 cases. The preoperative International Knee Documentation Committee (IKDC) score was 70.28±6.12, and the Lysholm score was 63.27±7.62. All patients underwent arthroscopic single-bundle ACL reconstruction, and the tibial tunnel was created through the anterolateral, high anteromedial, and additional low anteromedial approaches.

Results

All incisions healed by the first intention. All patients were followed up 18.7 months on average (range, 14-32 months). The three-dimensional CT at 3 days after operation showed that the tibial tunnel positions were accurate and the middle points were located in the 36.81%-43.35% of tibial plateau on sagittal plane. The medial borders of the tibial tunnel on coronal plane were located at the lateral to the medial eminence of the tibia. There were 3 cases of thrombosis of intermuscular vein of lower limbs, 2 cases of joint swelling and pain, and 3 cases of stiffness of knee joint. At last follow-up, the Lachman tests of all patients were negative and the pivot shift test were negative in 42 patients and positive in 3 patients (grade Ⅰ). The IKDC score (92.59±4.36) and Lysholm score (93.15±5.53) were significantly higher than preoperative scores ( t=11.35, P=0.00; t=12.27, P=0.00).

Conclusion

Arthroscopic ACL reconstruction via tibial tunnel made by three-portal technique, which was simple and accurate, can obtain the satisfactory function of the knee in the early stage after operation.

Editorial Commentary: Anterior Cruciate Ligament Graft Tunnel Mismatch: The Long and Short of It

Anterior cruciate ligament graft size is an important consideration when planning the length of the tibial tunnel. In general, longer grafts require longer tunnels to accommodate the graft. Ideally, the tibial bone plug should be flush with the tibial cortex after graft passage and femoral fixation. Alternatively, allograft bone-patellar tendon-bone grafts can be selected based on their lengths to assure an ideal fit in the tibial tunnel. However, there are increased risks of allograft failure in young patients that anterior cruciate ligament surgeons should recognize.

The posterior horn of the lateral meniscus is a reliable novel landmark for femoral tunnel placement in ACL reconstruction

PURPOSE

Femoral tunnel placement is essential for good outcome in anterior cruciate ligament (ACL) reconstruction. In the past, several attempts have been made to optimize femoral tunnel placement. It was observed that the posterior horn of the lateral meniscus was always located directly below to the desired femoral ACL tunnel position, when the knee was brought to deep flexion (> 120°). The goal of the present study was to verify the hypothesis that the posterior horn of the lateral meniscus can be used as a landmark for femoral tunnel placement.

METHODS

Out of a consecutive series of ACL reconstructions done by a single surgeon, 55 lateral radiographs were evaluated according to the quadrant method by Bernard and Hertel. Additionally, on anterior-posterior radiographs the femoral tunnel angle was determined.

RESULTS

In the present case series the posterior horn of the lateral meniscus could be identified and used as a landmark for femoral tunnel placement in all cases. The mean tunnel depth was 24 ± 5.1% and the mean tunnel height was 31.3 ± 5.7%. The mean femoral tunnel angle was 41 ± 4.9° using the anatomical axis as a reference. Compared to previous cadaver studies the data of the present study were within their anatomical range of the native ACL insertion site.

CONCLUSION

The suggested technique using the posterior horn of the lateral meniscus as a landmark for femoral tunnel placement showed reproducible results and matches the native ACL insertion site compared to previous cadaveric studies. In particular, non-experienced ACL surgeons will benefit from this apparent landmark and the corresponding easy-to-use ACL reconstruction method.

LEVEL OF EVIDENCE

IV.