Creation of an anatomic femoral tunnel with minimal damage to the remnant bundle in remnant-preserving anterior cruciate ligament reconstruction using an outside-in technique

Lateral femoral tunnel preparation and graft fixation for anterior cruciate ligament reconstruction-A discussion

This article provides a discussion and commentary around the recent advances in arthroscopic anterior cruciate ligament reconstruction (ACLR), with a focus on the aspects of lateral femoral tunnel preparation and graft fixation techniques. The paper explores and comments on a recently published review by Dai et al, titled "Research progress on preparation of lateral femoral tunnel and graft fixation in ACLR", while providing insight into its relevance within the field of ACLR, and recommendations for future research.

Modification of Outside-In Technique In Preparing Femoral Tunnel During Anterior Cruciate Ligament Reconstruction-"PL-Portal Outside-In Technique"

We propose modifying the outside-in technique by adopting a posterolateral (PL) portal as the working portal to introduce the anterior cruciate ligament reconstruction (ACLR) aiming guide while keeping the anteromedial portal as the viewing portal, the "PL-portal outside-in technique." This modification facilitates the preparation of an anatomical femoral tunnel, even when preserving a "big" ACL remnant or in small joint scenarios, such as pediatric ACLR. There is a minimal learning curve in adopting this technique because a standard 30° arthroscope is used, and the viewing portal is anterior.

Remnant preserving ACL reconstruction with a functional remnant is related to improved laxity but not to improved clinical outcomes in comparison to a nonfunctional remnant

PURPOSE

The Anterior cruciate ligament (ACL) remnant has been pointed out as a ligamentization enhancer. Nonetheless, the remaining tissue can be functional if it still provides some stability or nonfunctional. This study intends to compare the clinical results and knee stability of functional vs. nonfunctional remnant preservation ACL reconstruction (ACLR).

METHODS

One hundred and seventy-five patients with ACL injuries were included and underwent remnant preservation ACLR. They were divided into two groups accordingly to remnant tissue functionality: functional (Group F) and nonfunctional (Group NF). Primary outcome was defined as patient reported outcomes measured with Lysholm, IKDC and Tegner continuous scales and improvements. Secondary outcomes comprised of Lachman test, anterior drawer test, pivot shift test, extension and flexion deficit, graft coverage by remnant preserved tissue and failure rate (persistent instability or new ACL lesion). Menisci lesions, cartilage lesions and time to surgery were also recorded for each group.

RESULTS

One hundred and forty-four patients were available at a mean of 30.2 ± 10.1 months: 69 Functional and 75 Nonfunctional. Lysholm, IKDC and Tegner functional outcomes demonstrated no difference between the groups, Functional compared to Nonfunctional: 88.4 ± 10.5 vs. 92.2 ± 4.9, n.s. and 83.2 ± 11.3 vs. 87 ± 5.3, n.s. and 6 (5-10) vs. 6 (5-9), n.s., respectively. Lysholm and IKDC functional outcomes improvements demonstrated differences between the groups: Functional compared to Nonfunctional (39.3 ± 9.4 vs. 42.3 ± 7.4, p = 0.014 and 37.7 ± 10 vs. 41.0 ± 6.6, p = 0.032); however, they were not clinically significant. Functional group showed more stability on physical examination pre- and post-operatively (p < 0.001, p < 0.001). There was no difference regarding extension deficit (n.s.); however, functional group had more flexion deficit (p = 0.02). Nonfunctional group had better graft coverage (p = 0.001). There was no difference regarding failure rate: 4% vs. 9%, (n.s.).

CONCLUSION

Both remnant preservation ACLR techniques were able to achieve satisfactory functional outcomes. A functional remnant was not related to improved functional outcomes in comparison to a nonfunctional remnant; however, it was related to less laxity pre and postoperatively and inferior graft coverage.

LEVEL OF EVIDENCE

II.

Remnant preservation may improve proprioception after anterior cruciate ligament reconstruction

Aim

Our aim was to evaluate the literature investigating proprioception improvement after anterior cruciate ligament reconstruction (ACLR) and test the hypothesis that ACL tibial remnant-preserving reconstruction (ACLR-R) is more beneficial than standard technique (ACLR-S) in terms of postoperative proprioceptive function with various reported tests, including joint position sense (JPS) and threshold to detect passive motion (TTDPM).

Methods

An online search was performed in Embase, MEDLINE/PubMed, Cochrane, SPORTDiscus, and Web of Science databases before 5 October 2020, on the basis of the guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Key terms [(‘ACLR’ or ‘ACL-R’ or ‘anterior cruciate ligament reconstruction’) AND (‘remnant’ or ‘stump’) AND (‘proprioception’ or ‘proprioceptive’)] were used. The Oxford Centre for Evidence-Based Medicine and The McMaster Critical Review Form for Quantitative Studies were used for quality assessment. In total, four articles comparing proprioceptive functions between ACLR-R and ACLR-S were included, two of which were randomized clinical trials rated as level of evidence II, and two were retrospective cohort studies rated as level of evidence III. The outcomes were then compared. Evaluation of proprioception involved joint position sense (JPS) [reproduction of active positioning (RAP) and reproduction of passive positioning (RPP)] and threshold to detect passive motion (TTDPM) tests.

Results

Only four studies were included, with a total of 234 patients (119 ACLR-R patients and 115 ACLR-S patients). High heterogeneity in characteristics and outcome measurements was observed among the studies. Three studies performed sparing technique, and one performed tensioning technique. One study tested RAP and reported better results at an average of 7 months follow-up in ACLR-R (P < 0.05). Three studies tested RPP, one of which measured RPP within 12 months after surgery and reported better results in ACLR-R than in ACLR-S (P < 0.05). The other two studies reported similar results; however, the findings of one study were statistically insignificant. TTDPM was tested in one study, with no statistically significant difference found.

Conclusion

The current literature, although limited, reported proprioception improvement after ACLR-R (compared with ACLR-S) in terms of JPS. However, owing to the heterogeneity of the relevant studies, further research is required to determine remnant preservation effect on knee proprioceptive restoration.

Level of evidence

Level III, systematic review of Level II and III studies.

Femoral Footprint Visualization Using a Transtibial Portal in Anterior Cruciate Ligament Reconstruction

In traditional endoscopic anterior cruciate ligament (ACL) reconstruction, inadequate visualization of the femoral footprint through a lateral portal frequently causes surgical errors. Although various portal locations have been reported, no study has identified ideal locations for specific portals in relation to ACL reconstruction. This article presents the new transtibial portal technique (ie, the use of an existing tibial tunnel). This technique provides excellent direct visualization of the femoral ACL footprint without the need to create additional portals. It allows dynamic visualization of the relationship of the future graft with posterior cruciate ligament and bone structures. [Orthopedics. 2021;44(5):e691-e693.].

One-Stage Anatomical Revision Anterior Cruciate Ligament Reconstruction: Results According to Tunnel Overlaps

PURPOSE

To present clinical results according to tunnel overlap in 1-stage anatomical revision anterior cruciate ligament reconstruction (ACLR).

METHODS

All patients who underwent revision ACLR performed by a single surgeon (J.H.A.) from 2012 to 2017 and were followed up for >24 months were retrospectively evaluated. The exclusion criteria were concomitant ligament injury, including medial collateral ligament injury, modified Outerbridge grade ≥3 cartilage lesion, and severe meniscus defects. Tunnel overlap was measured on 3-dimensionally reconstructed computed tomography images. Patients in the nonoverlapped femoral tunnel group (group NO, n = 52) were treated with new tunnel drilling that completely avoided previous tunnels, and those in the overlapped femoral tunnel group (group O, n = 41) were treated with a new tunnel that overlapped with previous tunnels. Clinical outcomes were evaluated using the subjective International Knee Documentation Committee (IKDC) and Lysholm scores. Knee joint stability was measured using the Lachman and pivot shift tests. Patients with femoral tunnel widening of ≥14 mm underwent 2-stage ACLR.

RESULTS

The mean follow-up duration of 93 patients was 46.9 months (range, 24-97 months). All preoperative subjective and objective IKDC (P<0.001) and Telos stress test scores (P = .016) were significantly improved at the last follow-up. Forty-one patients had overlapping femoral tunnels, whereas 87 had overlapping tibial tunnels. At the last follow-up, subjective IKDC and Lysholm scores (73.6 ± 15.3 vs 74.9 ± 12.1, P = .799 and 80.0 ± 19.2 vs 81.44 ± 13.5, P = .505, respectively) and objective pivot shift (IKDC grade) in the Lachman test (P = .183 and P = .450, respectively) did not differ significantly between groups NO and O, respectively.

CONCLUSIONS

One-stage anatomical revision ACLR significantly improved the clinical results. Most tibial tunnels (94%) and approximately one-half (44%) of the femoral tunnels overlapped. The overlapped femoral tunnel group did not show inferior outcomes or stability.

LEVEL OF EVIDENCE

Level III, cohort study.

Remnant-Tensioning Single-Bundle Anterior Cruciate Ligament Reconstruction Provides Comparable Stability to and Better Graft Vascularity Than Double-Bundle Anterior Cruciate Ligament Reconstruction in Acute or Subacute Injury: A Prospective Randomized Controlled Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging

PURPOSE

To compare the clinical, second-look arthroscopic, magnetic resonance imaging (MRI), and dynamic-contrast-enhanced MRI (DCE-MRI) findings between remnant-tensioning single-bundle (RT-SB) and double-bundle (DB) anterior cruciate ligament reconstruction (ACLR).

METHODS

Sixty-seven patients with acute or subacute anterior cruciate ligament (ACL) injury were randomized to undergo RT-SB or DB ACLR. Twenty-six patients in the RT-SB group and 28 in the DB group were evaluated using stability tests (Lachman test, pivot-shift test, and KT-2000 arthrometer) and multiple clinical scores. One year postoperatively, all 54 patients underwent MRI for evaluation of graft continuity and graft signal/noise quotient and DCE-MRI for the calculation of normalized area under the curve (nAUC) as a marker of graft vascularity. Among them, 41 patients underwent second-look arthroscopy for the evaluation of graft continuity, graft tension, and synovialization. The results were compared between the 2 groups.

RESULTS

At the minimum 2-year follow-up (28.7 ± 6.4 months), the stability tests, clinical scores, second-look arthroscopic findings, and MRI findings were not significantly different between the groups. However, the mean nAUC values on DCE-MRI for the ACL graft were significantly higher in the RT-SB group than those in the DB group in all 3 zones (nAUC_proximal, P = .005; nAUC_middle, P = .021; nAUC_distal, P = .027; and nAUC_average, P = .008).

CONCLUSION

For acute or subacute ACL injury, the RT-SB ACLR showed an outcome comparable to that of DB ACLR in terms of knee stability, clinical scores, MRI findings, and second-look arthroscopic findings. Moreover, RT-SB ACLR showed better graft vascularity 1 year postoperatively than DB ACLR using DCE-MRI.

LEVEL OF EVIDENCE

II, prospective randomized controlled trial.

Femoral tunnel placement in single-bundle, remnant-preserving anterior cruciate ligament reconstruction using a posterior trans-septal portal

BACKGROUND

Anatomic tunnel formation and remnant preservation are valuable aspects of anterior cruciate ligament (ACL) reconstruction. However, anatomic landmarks are difficult to observe during remnant-preserving ACL reconstruction (ACLR). The aims of this study were to evaluate the: 1) femoral tunnel location created with guidance from the apex of the deep cartilage margin (ADC) and footprint compared to anatomical reference; and 2) relationship between femoral tunnel location and outcomes of ACLR.

METHODS

A total of 109 ACLR patients without revision ACLR, multi-ligament reconstruction, peri-knee fracture, and osteotomy were included. The femoral tunnel was formed at the most proximal corner of the femoral footprint using a posterior trans-septal portal as the viewing portal. The distance from the tunnel center to ADC was measured by computed tomography and arthroscopy. The two measurements were then compared. Finally, femoral tunnel location was compared to the anatomic reference and correlated with the outcomes.

RESULTS

The average distance from ADC to the femoral tunnel center was 7.0 ± 1.4 mm as measured by arthroscopy, and 7.2 ± 2.0 mm using three-dimensional computed tomography. There was no statistically significant difference between the two methods (P = 0.420). Clinical and stability outcomes were significantly improved postoperatively. Clinical outcome was not related to femoral tunnel location; however, stability outcome was related to femoral tunnel location: the more proximally located femoral tunnels showed better stability.

CONCLUSION

The ADC can be a possible landmark in remnant-preserving ACLR using a trans-septal portal. A more proximal femoral tunnel, which is located at the proximal corner of the ACL remnant, can provide stability advantage during remnant-preserving ACLR.

Magnetic Resonance Imaging and Clinical Results of Outside-in Anterior Cruciate Ligament Reconstruction: A Comparison of Fixed- and Adjustable-Length Loop Cortical Fixation

Background

Cortical suspensory femoral fixation is commonly performed for graft fixation to the femur in anterior cruciate ligament (ACL) reconstruction using hamstring tendons. The purpose of this study was to compare graft healing in the femoral tunnel, implant-related failure, and clinical results between fixed- and adjustable-length loop devices in outside-in ACL reconstruction.

Methods

A total of 109 patients who underwent ACL reconstruction using the outside-in technique from December 2010 to July 2014 were included. For femoral graft fixation, a fixed-length loop device was used in 48 patients (fixed-loop group) and an adjustable-length loop device was used in 61 patients (adjustable-loop group). For evaluation of graft healing in the femoral tunnel, magnetic resonance imaging was performed at postoperative 6 months and the signal-to-noise ratios (SNRs) of the tendon graft and tendon-bone interface in the femoral bone tunnel were evaluated. The presence of synovial fluid was evaluated to determine loop lengthening at the femoral tunnel exit. Clinical results assessed using International Knee Documentation Committee score, Tegner-Lysholm Knee Scoring scale, and knee instability tests were compared between groups.

Results

The SNRs of the tendon graft and tendon-bone interface were not statistically different between groups. The presence of synovial fluid at the femoral exit showed no statistical difference between groups. Clinical results were not significantly different between groups.

Conclusions

The adjustable-length loop device provided comparable graft healing, implant-related failure, and clinical results with the fixed-length loop device, allowing adaptation of the graft to the different tunnel lengths. Therefore, it could be effectively used with an adjustment according to the femoral tunnel length.

Remnant-preserving and re-tensioning technique to cover the graft in anterior cruciate ligament reconstruction

PURPOSE

This study set out to assess the clinical and radiographic outcomes and the extent of synovial coverage on second-look arthroscopy of anterior cruciate ligament (ACL) reconstruction using a remnant-preserving and re-tensioning technique to easily cover the graft with a remnant.

METHODS

Forty-three subjects with ACL rupture underwent remnant-preserving and re-tensioning ACL reconstruction using a free tendon Achilles allograft between 2011 and 2013. The clinical outcomes were assessed by Lysholm knee score, Lachman stress test, pivot shift test, International Knee Documentation Committee (IKDC) classification, and Tegner Activity Scale score. Side-to-side difference (SSD) was assessed on stress radiographs. The extent of synovialization was evaluated on second-look arthroscopy.

RESULTS

The mean Lysholm score was 54 ± 11 before surgery and 94 ± 5 at the last follow-up (p < 0.001). On Lachman stress test, 42 subjects had grade 0 or 1 on the Lachman stress test, and 42 had grade 0 or 1 on the pivot shift test. Forty-one subjects had IKDC classification A or B; two were classified as C or D. The median Tegner Activity Scale score was 6.5 (range 5-9) before injury and 6 (range 4-8) at the last follow-up (p = 0.048). Mean SSD on stress radiographs was 9.9 ± 2.6 mm preoperatively and 1.0 ± 1.7 mm at the last follow-up (p < 0.001). In the assessment of the extent of synovial coverage of the graft, 39 subjects were in group 1 (>75 %) for synovial coverage of the graft, three were in group 2 (50-75 %), and one was in group 4 (≤25 %).

CONCLUSIONS

The remnant-preserving and re-tensioning technique resulted in satisfying short-term results clinically and radiologically and good synovial coverage on second-look arthroscopy.

LEVEL OF EVIDENCE

Case series, Level IV.

Comparison of transtibial and retrograde outside-in techniques of anterior cruciate ligament reconstruction in terms of graft nature and clinical outcomes: a case control study using 3T MRI

INTRODUCTION

This study was performed to compare ACL graft maturation and morphologies using MRI between trans-tibial (TT) and retrograde outside-in (OI) techniques, and to compare clinical outcomes between the two groups.

MATERIALS AND METHODS

Patients underwent single-tunnel ACL reconstruction using quadrupled hamstring autografts, with the TT technique used on 42 patients (TT group) and the retrograde OI technique used on 39 patients (OI group). All patients were examined with 3 T MRI at 6 months (between 5 and 7 months) after surgery. The signal intensity of the reconstructed graft was analyzed and compared between the two groups, using the signal/noise quotient (SNQ), the orientation of the ACL graft and the tibial tunnel location of the graft. The SNQ value is indicative of graft maturation, and the orientation of the graft and the tibial tunnel location of the graft represent graft morphology. Clinical evaluation was performed before the surgery and 2 years or more after the surgery.

RESULTS

The mean SNQ value of the TT group was significantly (P = 0.030) lower than that of the OI group. The mean sagittal ACL angle (P < 0.001) and the mean coronal ACL angle (P < 0.001) were more vertical in the TT group. The tibial tunnel aperture was located at a significantly (P < 0.001) more posterior position in the TT group. There was no statistically significant difference in the clinical results between the two groups.

CONCLUSIONS

The OI technique showed a more anteriorly positioned tibial tunnel and a more oblique graft orientation in both sagittal and coronal planes. However, in comparison with the TT group, a significantly higher SNQ value was noticed in the follow-up MRI of the OI group at 6 months, although clinical results of the two groups were not significantly different during at least the 2-year follow-up.

Three-Dimensional Reconstruction Computed Tomography Evaluation of the Tunnel Location and Angle in Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction: A Comparison of the Anteromedial Portal and Outside-in Techniques

Purpose

The purpose of this study was to compare the geometry and position of the femoral tunnel between the anteromedial portal (AMP) and outside-in (OI) techniques after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction.

Materials and Methods

We evaluated 82 patients undergoing single-bundle ACL reconstruction with hamstring autografts using either the AMP (n=40) or OI (n=42) technique. The locations of the tunnel apertures were assessed by postoperative 3-dimensional computed tomography imaging. The femoral graft bending angle, femoral tunnel aperture shape, femoral tunnel length, and posterior wall breakage were also measured.

Results

The mean femoral tunnel position parallel to the Blumensaat line was more caudally positioned in the AMP group than in the OI group (p=0.025) The mean femoral graft angle in the OI group (99.6°±7.1°) was significantly more acute than that of the AMP group (108.9°±10.2°, p<0.001). The mean height/width ratio of the AMP group (1.21±0.20) was significantly more ellipsoidal than that of the OI group (1.07±0.09, p<0.001).

Conclusions

The mean femoral tunnel position was significantly shallower in the AMP technique than in the OI technique. The OI technique might be more disadvantageous than the AMP technique in terms of the more acute bending angle.

Management of Anterior Cruciate Ligament Injury: What's In and What's Out?

Sports medicine physicians have a keen clinical and research interest in the anterior cruciate ligament (ACL). The biomechanical, biologic, and clinical data researchers generate, help drive injury management and prevention practices globally. The current concepts in ACL injury and surgery are being shaped by technological advances, expansion in basic science research, resurging interest in ACL preservation, and expanding efforts regarding injury prevention. As new methods are being developed in this field, the primary goal of safely improving patient outcomes will be a unifying principle. With this review, we provide an overview of topics currently in controversy or debate, and we identify paradigm shifts in the understanding, management, and prevention of ACL tears.

Accuracy and Reproducibility of the Femoral Tunnel With Different Viewing Techniques in the ACL Reconstruction

The purpose of this study was to compare the accuracy and reproducibility of the femoral tunnel location among 3 different viewing techniques used during outside-in anterior cruciate ligament (ACL) reconstruction with 3- dimensional (3-D) computed tomography (CT): (1) an anterolateral (AL) or anteromedial (AM) portal with a 30° arthroscope (A group) vs (2) a posterolateral (PL) portal with a 70° arthroscope (PL group) vs (3) a trans-septal (TS) portal with a 30° arthroscope (TS group). A total of 106 patients undergoing outside-in ACL reconstruction were recruited. Patients were divided into 3 groups according to viewing technique (A group=36 patients; PL group=35 patients; TS group=35 patients). Femoral tunnel locations were evaluated with the quadrant method and the anatomic coordinate axes measurement (ACAM) method in the medial wall of the lateral femoral condyle using 3-D reconstructed CT. The accuracy and reproducibility of the femoral tunnel locations were compared among the 3 techniques. The accuracy of the tunnel location was higher in the TS group by the quadrant method as well as the ACAM method. The reproducibility of the femoral tunnel position in the TS group was the highest, and the femoral tunnel locations of the TS group were more compactly distributed compared with those of the A and PL groups. The accuracy and reproducibility of the femoral tunnel location could be improved with a TS portal viewed using a 30° arthroscope. Anteromedial/anterolateral and PL portals viewed using a 70° arthroscope showed no difference. [Orthopedics. 2016; 39(6):e1085-e1091.].

Behind-remnant arthroscopic observation and scoring of femoral attachment of injured anterior cruciate ligament

PURPOSE

To describe the femoral anterior cruciate ligament (ACL) attachment based on the behind-remnant observation with a new scoring system and to investigate the characteristics of an ACL injured knee.

METHODS

One hundred and twenty-six ACL injured knees with four standardized arthroscopic photos and full evaluation under anaesthesia were included in the study. Sixty non-ACL injured knees were also evaluated as control. A scoring system for the femoral ACL attachment was set as follows based on behind-remnant findings; the direct insertion was divided into three portions as proximal, middle and distal. The fibrous extension from the articular surface (indirect insertion) and the severity of synovitis were also graded into 2, 1 and 0 points. The total score was 10 as full marks. The correlation between each score and total score, as well as age at surgery, gender, anterior laxity, pivot-shift test and meniscus injuries, was statistically evaluated with a significance of 0.05.

RESULTS

The femoral attachment score of the ACL injured knees was statistically different from that of the non-ACL injured knees. Anterior laxity was dependent only on the integrity of the proximal portion. Knee instability was significantly correlated with the status of the direct insertion. Medial and lateral meniscus injuries were correlated with the middle part and the distal part of the direct insertion, respectively. The direct insertion was less preserved in distal and articular sides.

CONCLUSION

Arthroscopic observation behind the remnant of the injured ACL showed clearer findings of the femoral attachment than that from the front. Behind-remnant observation greatly assists in the creation of a correct anatomical tunnel with the preserving remnant. The scoring system indicated several significant correlations between the score and preoperative patient status.

Graft bending angle is correlated with femoral intraosseous graft signal intensity in anterior cruciate ligament reconstruction using the outside-in technique

BACKGROUND

The purposes of this study were as follows: 1) to determine the correlation between the bending angle of the anterior cruciate ligament (ACL) graft at the femoral tunnel and the magnetic resonance imaging (MRI) signal intensity of the ACL graft and 2) to analyze the difference in the MRI signal intensity of the reconstructed ACL graft in different areas of the graft after single-bundle hamstring autograft ACL (SB ACL) reconstruction using an outside-in (OI) technique with bone-sparing retro-reaming.

METHODS

Thirty-eight patients who underwent SB ACL reconstruction with the hamstring tendon autograft using the OI technique were enrolled in this study. All patients were assessed using three-dimensional computed tomography (CT) to evaluate femoral tunnel factors, including tunnel placement, tunnel length, tunnel diameter, and femoral tunnel bending angle. At a mean of 6.3±0.8months after surgery, 3.0-T MRI was used to evaluate the graft signal intensity using signal/noise quotient for high-signal-intensity lesions.

RESULTS

Among various femoral tunnel factors, only the femoral tunnel bending angle in the coronal plane was significantly (p=0.003) correlated with the signal/noise quotient of the femoral intraosseous graft. The femoral intraosseous graft had significantly (p=0.009) higher signal intensity than the other graft zone. Five cases (13.2%) showed high-signal-intensity zones around the femoral tunnel but not around the tibial tunnel.

CONCLUSION

After ACL reconstruction using the OI technique, the graft bending angle was found to be significantly correlated with the femoral intraosseous graft signal intensity, indicating that increased signal intensity by acute graft bending might be related to the maturation of the graft.

LEVEL OF EVIDENCE

This was a retrospective comparative study with Level III evidence.

Anterior cruciate ligament reconstruction, rehabilitation, and return to play: 2015 update

Anatomical discoveries and a growing appreciation of the knee as a complex organ are driving innovations in patient care decision-making following anterior cruciate ligament (ACL) injury. Surgeons are increasing their efforts to restore combined mechanical-neurosensory ACL function and placing more consideration on when to reconstruct versus repair native anatomical structures. Surgical options now include primary repair with or without reinforcing the injured ACL with suture-based internal bracing, and growing evidence supports biological augmentation using platelet-rich plasma and mesenchymal stem cells to enhance tissue healing. Physical therapists and athletic trainers are increasing their efforts to facilitate greater athlete cognitive engagement during therapeutic exercise performance to better restore nonimpaired neuromuscular control activation amplitude and timing. Knee brace design and use needs to evolve to better match these innovations and their influence on the rehabilitation plan timetable. There is a growing appreciation for the multifaceted characteristics of the rehabilitation process and how they influence neuromuscular, educational, and psychobehavioral treatment goal achievement. Multiple sources may influence the athlete during the return to sports process and clinical outcome measures need to be refined to better evaluate these influences. This update summarizes contemporary ACL surgical, medical, and rehabilitation interventions and future trends.

A new behind-remnant approach for remnant-preserving double-bundle anterior cruciate ligament reconstruction compared with a standard approach

PURPOSE

To introduce a new behind-remnant approach for double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and to compare the femoral tunnel positions of anteromedial (AM) and posterolateral (PL) bundles between the new and standard procedures by a three-dimensional computed tomography (3D-CT).

METHODS

During DB ACL reconstruction, two approaches for femoral tunnel creation were consecutively practiced from 2010 to 2012. The patients were evaluated retrospectively as a cohort study. A total of 200 primary ACL reconstructions have been performed using a transtibial approach. One approach was a standard approach from the front in which the ACL remnant was peeled off from the attachment, and two guide wires were inserted based on anatomic bony landmarks (standard group). The other approach was a new behind-remnant approach in which the ACL remnant was kept untouched and two guide wires were inserted at the posterior margin of the direct ACL insertion (behind-remnant group). The position of the AM and PL femoral tunnels was expressed on a 3D-CT reconstructive image using the quadrant method with a statistical analysis.

RESULTS

The depth of the AM center was 24 ± 6 % (mean and standard deviation) in the standard group and 22 ± 5 % in the behind-remnant group. The height of the AM tunnel center was 22 ± 8 % in the standard group and 31 ± 8 % in the behind-remnant group. The depth of the PL tunnel center was 32 ± 6 % in the standard group and 35 ± 5 % in the behind-remnant group. The height of the PL tunnel center was 47 ± 9 % in the standard group and 55 ± 7 % in the behind-remnant group. The AM and PL femoral tunnels in both groups were created within the normal anatomic footprint of the previous studies. The behind-remnant approach created a significantly lower femoral tunnel for both AM (p = 0.000) and PL tunnels (p = 0.000). The depth of both AM and PL tunnels was not significantly different between the two groups (n.s.).

CONCLUSION

The new behind-remnant procedure is technically simple and reproducible as a remnant-preserving ACL reconstruction.

LEVEL OF EVIDENCE

Cohort study, Level III.

Femoral Footprint Reconstruction With a Direct Viewing of the Posterior Insertion Using a Trans-Septal Portal in the Outside-In Anterior Cruciate Ligament Reconstruction

We established a technique for femoral tunnel preparation through direct vision of the femoral footprint with maximum preservation to the native anterior cruciate ligament (ACL) remnant using a posterior trans-septal portal. Anterior arthroscopy is difficult for the proper tunnel placement without sacrificing the ACL remnant. Posterior arthroscopy could be helpful for viewing the posterior insertion of the ACL remnant that provides excellent femoral footprint exposure without sacrificing the native ACL remnant. Therefore, a posterolateral portal technique using a 70° arthroscope through a posterolateral portal is introduced. However, using the 70° arthroscope, an oblique view is displayed and distorted view could be seen. Therefore, to achieve the goal of posterior arthroscopy and avoid obstacles of the posterolateral view with the 70° arthroscope, we introduce this technique that uses the posterior trans-septal portal with a 30° arthroscope that provides an excellent viewing to the femoral footprint through a hole of the posterior septum.

Placement of Double Tunnels in ACL Reconstruction Using Bony Landmarks Versus Existing Footprint Remnant: A Prospective Clinical Study With 2-Year Follow-up

BACKGROUND

The outcomes of double-bundle anterior cruciate ligament reconstruction (DB-ACLR) are becoming controversial. One of the main reasons for the controversy is the techniques for bone tunnel placement. The common technique to place the bone tunnels is to use bony landmarks, while a new approach uses footprint remnants.

PURPOSE

To investigate if placement of double tunnels using bony landmarks produces the same clinical results as that of using existing footprint remnants.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A total of 72 male patients were randomly divided into 2 groups of 36 patients each: (A) DB-ACLR tunnel placement using the footprint remnant procedure (EF group) and (B) DB-ACLR tunnel placement using the bony landmark procedure (BL group). All patients were evaluated before and after surgery. Outcomes were measured by KT-2000 arthrometer side-to-side difference, pivot-shift test, and Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scores. Second-look arthroscopic evaluations were performed in 59 cases (28 and 31 cases in the EF and BL groups, respectively).

RESULTS

The mean follow-up time was 36.9±4.8 months. Postoperative 3-dimensional computed tomography scans showed that bone sockets were variable on both femoral and tibial sides in the EF group and almost consistent in the BL group. All of the evaluation indexes were significantly improved postoperatively in both groups. There were no revision cases in the EF group and 2 in the BL group. The EF group showed a faster range of motion (ROM) recovery (at 0° to 120°) than did the BL group. At final follow-up, there was no significant difference between the EF and BL groups in Tegner score (5.88±1.39 vs 5.16±1.76; P=.058) or pivot-shift test (34 vs 32; P=.067). The EF group had a larger proportion of patients with IKDC grade A (normal) (33 vs 24; P<.020), smaller side-to-side difference (0.68±0.38 mm vs 1.23±0.61 mm; P<.001), higher Lysholm score (91.29±4.90 vs 88.71±5.09; P=.032), and better second-look arthroscopic evaluations for graft quality in the anteromedial (P=.034), posterolateral (P=.015), and combined bundles (P=.029) compared with the BL group.

CONCLUSION

Although both techniques provided satisfactory clinical results, DB-ACLR using the existing footprint remnant for tunnel placement showed better functional results with respect to faster ROM recovery, higher subjective outcome scores, and better arthroscopic second-look with no revision cases.

Re-tensioning technique to cover the graft with remnant in anterior cruciate ligament reconstruction

A number of remnant-preserving techniques to restore proprioceptive function in anterior cruciate ligament reconstruction have been described. However, they might not cover the significant amount of the graft with the synovium of the remnant in many cases. We introduce a simple technique that can cover nearly the entire graft with the synovium by re-tensioning the remnant, which might enhance synovialization of the graft and restoration of proprioception.