Hamstring grafts for anterior cruciate ligament reconstruction show better magnetic resonance features when tibial insertion is preserved

Age-specific over-the-top techniques for physeal sparing anterior cruciate ligament (ACL) reconstruction in skeletally immature patients: Current concepts for prepubescents to older adolescents

Tailored surgical strategies for anterior cruciate ligament (ACL) reconstruction in skeletally immature patients are presented, emphasizing techniques to minimize growth plate damage and ensure stability. As ACL injuries in youth increase, delaying surgery can lead to joint damage and poor recovery outcomes. Using magnetic resonance imaging-based assessments of skeletal maturity, the authors propose the 'over-the-top (OTT)' approach with lateral tenodesis, adapted for three growth stages: prepubescents, young adolescents and older adolescents. For prepubescents, the extra-physeal approach avoids growth plate drilling; for young adolescents, the supra-physeal technique places tunnels above the growth plate; and for older adolescents, the trans-physeal method mirrors adult techniques, as growth plates are closing. The minimally invasive OTT technique preserves hamstring insertion, ensures isometric graft placement, and allows for combined intra- and extra-articular procedures to improve rotational control and protect the graft. Clinical outcomes highlight high return-to-sport rates, minimal growth disturbances, and low failure rates, although older adolescents show higher graft failures due to activity levels. Various adaptations of the OTT and lateral tenodesis techniques utilizing hamstring tendons provide promising solutions for addressing ACL injuries in skeletally immature patients, ranging from prepubescence to late adolescence. Assessing skeletal age and estimating remaining bone growth are essential for selecting the most appropriate surgical method. The biomechanical principles and positive clinical results observed across different patient groups highlight these techniques as effective, safe and attractive options for managing these challenging cases. LEVEL OF EVIDENCE: Level IV.

No Difference in Graft Signal Intensity on MRI or Clinical Outcome Between Anterior Cruciate Ligament Reconstruction With and Without Suture Augmentation

PURPOSE

To evaluate the safety of anterior cruciate ligament reconstruction (ACLR) with suture augmentation (SA) through clinical evaluations, monitoring of complications, and evaluation of early graft remodeling using magnetic resonance imaging (MRI).

METHODS

Data of participants who underwent anatomic double-bundle ACLR using hamstring tendon autografts, with a minimum 2-year follow-up, were retrospectively reviewed. Participants undergoing ACLR with SA were propensity-matched with those without SA. Postoperative clinical evaluations, including Lysholm and Tegner activity scores, International Knee Documentation Committee (IKDC) evaluation scores, KT-1000 side-to-side difference for knee stability at a 2-year follow-up, and complications, were recorded. The minimal clinically important difference (MCID) was calculated for IKDC scores. The anteromedial bundle graft was categorized into distal, middle, and proximal regions on the 6-month and 1-year postoperative MRI. The signal-to-noise quotient (SNQ) of each region of interest was calculated to evaluate the graft signal intensity, which was compared between the two groups using Welch's t-test.

RESULTS

Fifty-three participants were included in each group. No significant differences were observed between the non-SA and SA groups in the Lysholm scores (96.6 ± 6.2; 95.3 ± 5.8, P = 0.25), Tegner activity scores (4.8 ± 1.4; 5.0 ± 1.3, P = 0.49), IKDC scores (90.4 ± 10.8; 87.1 ± 12.9, P = 0.15), percentage of patients meeting the MCID (94.3%; 83.0%, P = 0.12), or postoperative KT-1000 side-to-side difference (0.9 ±1.2; 0.7 ± 1.8 mm, P = 0.56). One (1.8%) and two (3.7%) cases of re-tears occurred in the non-SA and SA groups, respectively; no other complications occurred. The postoperative SNQ measurements revealed no significant differences in signal changes in all regions of the grafts between the two groups.

CONCLUSIONS

This study confirmed no difference in graft signal intensity on MRI or clinical outcome between ACLR with and without SA at the 2-year follow-up.

LEVEL OF EVIDENCE

Level III, retrospective, comparative study.

Outcomes of hamstring graft with preserved tibial insertion for ACL reconstruction: systematic review and meta-analysis

PURPOSE

Evaluate the outcomes of ACL (Anterior Cruciate Ligament) reconstruction techniques that use a hamstring graft with a preserved tibial insertion and compare them to standard techniques.

METHODS

A systematic literature review and meta-analysis was done of the PubMed, MEDLINE, Cochrane and Ovid databases to identify published clinical studies on ACL reconstruction in which a non-detached hamstring tendon (NDHT) was used as a graft and to compare them to studies in which a detached hamstring tendon (DHT) or other techniques were used. The eligible studies were analyzed for the knee laxity, Lachman test, pivot shift test, joint range of motion, anterior drawer, pain, re-tear, revision surgery, Lysholm score, Tegner score, ACL-RSI scale, KOOS, IKDC, SNQ and Howell scale.

RESULTS

Twelve articles in which NDHT was used for ACL reconstruction were analyzed. There was no significant difference between NDHT and DHT in the Lachman > 1 (p = .07), pivot shift test > 1 (p = .40), re-tears (p = .62), pain (p = .85) and the Tegner score (p = .95). However, the outcomes were somewhat better with the NDHT technique for the Lachman (RR = 0.30; 95% CI 0.08-1.12), pivot shift test (RR = 0.50; 95% CI 0.10-2.49) and re-tears (RR = 0.66; 95% CI 0.13-3.42). The other criteria were not included in the meta-analysis because of lack of data or because specific outcome scores were used in each article.

CONCLUSION

NDHT techniques provide similar results to DHT for ACL reconstruction and tend to produce better stability and a lower re-tear rate.

Preserving the hamstring tendon insertion during ACL reconstruction with an autograft: Systematic literature review

INTRODUCTION

The hamstring tendons (gracilis and semitendinosus) are often used as an autograft for anterior cruciate ligament (ACL) reconstruction. Healing of this graft involves a slow biological process called ligamentization. To encourage this process, some authors have proposed preserving the insertion of the hamstring tendons.

HYPOTHESIS

Leaving the tibial insertion of the hamstring tendons intact will provide better early biological incorporation and superior tibial mechanical fixation resulting in various clinical advantages.

MATERIALS AND METHODS

In January 2022, a systematic literature review was carried out independently by two authors of the Medline, PubMed and Embase databases. The keywords used were "pedicular" or "pedicled" or "preservation of tibial attachment" or "hamstring tibial insertion" AND "ACL reconstruction". Each author's data was analyzed separately.

RESULTS

Sixteen articles were analyzed. Preserving the hamstring tibial insertion during ACL reconstruction improves the graft's biological incorporation during the initial postoperative phase according to clinical studies with MRI analysis and provides a mechanical advantage at the graft's tibial attachment according to biomechanical studies (construct up to 65% stiffer). There was no difference in the clinical and functional scores when compared to the conventional technique in which the hamstring tendons are detached from their tibial insertion.

DISCUSSION

The main conclusion of this systematic literature review was that preserving the hamstring tibial insertion during ACL reconstruction appears to improve the graft's ligamentization with biological and mechanical advantages relative to detaching the hamstring tendons. The clinical and functional results were comparable to other techniques. Prospective studies with large cohorts are still needed to confirm these findings.

LEVEL OF EVIDENCE

IV; Systematic review of literature.

Combined Anterior Cruciate Ligament Reconstruction and Lateral Extra-Articular Tenodesis: The "Over-the-Top" Technique

Background

The anterior cruciate ligament (ACL) is a primary restraint to anteroposterior as well as rotatory knee laxity. In case of concomitant lesion of menisci or other ligamentous structures, further dynamic instability is encountered. A lateral extra-articular tenodesis (LET) augmentation has been proposed by the Authors to treat or prevent residual laxity.

Indications

ACL reconstruction is recommended in young athletes involved in pivoting sports, non-contact pivoting injuries, high-grade pivot shift, deep notch sign and double bone bruise, meniscal loss, and revision of previous bone-patellar tendon-bone autograft.

Technique Description

A 2 to 3 cm oblique incision is made over the pes anserinus. Gracilis and semitendinosus tendons are harvested with their attachment preserved and sutured together. Tibial tunnel is reamed after positioning of a guide pin. A wire-loop passer is directed from the tibial tunnel to the anteromedial portal. A 2 to 3 cm longitudinal incision is made superior-laterally, the ileotibial band is divided and retracted anteriorly. A suture-loop is retrieved from the lateral incision through the anteromedial portal with a curved Kelly clamp. The suture is placed into the wire-loop and retrieved with it from the tibial tunnel. The graft is retrieved from the lateral incision, tensioned with the knee at 70° to 90° of flexion and foot in neutral rotation and secured with 2 staples to the femur. A 1-cm skin incision is performed just below the Gerdy tubercle. The graft is retrieved from this incision below the fascia with a small Kelly clamp, tensioned and secured with a staple. The iliotibial tract defect is closed.

Results

At long-term follow-up, a revision rate of 3% has been reported, while patient-reported outcome measures (PROMs) were excellent. At very-long-term follow-up, most patients were still involved in sports with a very low rate of positive Lachman and pivot shift tests. No overconstraint and lateral osteoarthritis were encountered. Medial osteoarthritis was related only to medial meniscectomy.

Discussion/Conclusion

The ACL reconstruction plus LET over-the-top technique is a safe and reliable surgery with a low rate of reoperations and peri-operative complications at very-long-term follow-up.

Patient Consent Disclosure Statement

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction With Pedicular Hamstrings Tendon Graft, Single-Strand Gracilis for ALL and Single Blind Femoral Tunnel

Combined anterior cruciate ligament and anterolateral ligament reconstruction (ACL+ALL r) is a common procedure to treat rotational instability and to prevent ACL graft failure. Recent studies have described numerous combined reconstruction techniques to obtain the most anatomical procedure with the least graft donor site morbidity and the best clinical results. Hamstring (HG) grafts are the most popular graft in literature. Leaving pedicle HG can preserve enough blood supply to improve tendon-bone healing with additional mechanical fixation of the graft on the tibial side. A single femoral tunnel reduces bone loss and prevents convergence of 2 femoral tunnels. We describe an original ACL and ALL reconstruction technique that preserves hamstring tibial insertion with a single blind femoral tunnel.

Factors Affecting Graft Remodeling and Anterior Cruciate Ligament Reconstruction: MRI Study of 180 Knees

BACKGROUND

Several factors affect the retear rate after anterior cruciate ligament (ACL) reconstruction, but there are few data on which factors affect graft remodeling.

PURPOSE

To determine which factors are associated with the remodeling of an ACL graft.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective longitudinal study was conducted to investigate the relationship between various exposure factors and the occurrence of an "event": graft remodeling measured with the signal-to-noise quotient (SNQ). Data were collected prospectively and analyzed retrospectively for this study. The endpoint was the SNQ on magnetic resonance imaging at postoperative 1 year. The effect of the following parameters on SNQ was investigated: sex, smoking habits, age at surgery, body mass index, time to surgery, time to return to sports, type of sport (in-line, pivot, contact), type of graft (free semitendinosus [ST] or attached ST), and addition of lateral tenodesis.

RESULTS

An overall 180 patients were enrolled (90 with each technique). The following factors were significantly and independently associated with the SNQ: attached ST graft (β = -2.624668; P < .001), age at the time of surgery (β = -0.7948476; P = .012), and time elapsed between the injury event and surgery (β = -0.7137424; P = .046).

CONCLUSION

Leaving the ST graft attached distally, being older at the time of surgery, and having more time elapse between the injury event and ACL reconstruction surgery were significantly associated with better graft remodeling.

Extracorporeal Shockwave Therapy Improves Outcome after Primary Anterior Cruciate Ligament Reconstruction with Hamstring Tendons

PURPOSE

The decision regarding the timepoint of a return to sports after anterior cruciate ligament (ACL) reconstruction is complex and depends on many factors, including objectively tested physical and psychological readiness as well as biological healing. The aim of this study was to investigate the influence of repetitive extracorporeal shockwave therapy (ESWT) on return-to-sports duration, clinical results and MRI results after ACL reconstruction with hamstring tendons (HT).

MATERIAL AND METHODS

In this prospective controlled study, all patients with acute ACL ruptures were treated by ACL reconstruction with HT. Patients were randomized into two groups (Group A: ESWT group; Group B: control group). Patients in the ESWT group received focused shockwave therapy 4, 5 and 6 weeks after ACL surgery. Follow-up investigations including IKDC score, Lysholm score, VAS and evaluation regarding return-to-sports timepoints that were conducted 3-, 6-, 9- and 12-months post-operation. An MRI investigation was performed 12-months post-operation and graft maturation (signal intensity ratio (SIR)) as well as femoral and tibial tunnel characteristics (bone marrow oedema, tunnel fluid effusion) were assessed.

RESULTS

In total, 65 patients (27.65 ± 7.07 years; 35 male/30 female) were included in this study. The mean timepoint for "return-to-pivoting-sports" was 27.92 weeks (±2.99) in the ESWT group as well as 42.64 weeks (±5.18) in the control group (p < 0.001). In the ESWT group 31 patients (vs.

CONTROL GROUP

n = 6) attained the "pre-injury activity level", whereas 6 patients (vs.

CONTROL GROUP

n = 22) did not reach this level within 12 months post-operation. The IKDC score, Lysholm score, and VAS showed significant improvement in the ESWT group compared with the control group for all time-points (p < 0.001). The mean SIR in the ESWT group revealed 1.81 (±0.88), whereas the control group showed a mean SIR of 2.68 (±1.04) (p < 0.01).

DISCUSSION

In conclusion, this is the first study investigating the effect of repetitive ESWT on ACL reconstruction with clinical outcome measurements, including the duration of return-to-sports activity and an MRI follow-up examination. Return-to-sports parameters, clinical scores and graft maturation were significantly improved in the ESWT group. This study may support an earlier return-to-sports timepoint by ESWT and is of high clinical relevance as ESWT is a cost-effective treatment option with no relevant side effects.

Effect of a new remnant-preserving technique with anatomical double-bundle anterior cruciate ligament reconstruction on MRI-based graft maturity: a comparison cohort study

PURPOSE

To investigate the effects of a new remnant-preserving double-bundle anterior cruciate ligament reconstruction (ACLR) technique, focused on avoiding remnant damage and preserving continuity of remnants, on graft maturity using magnetic resonance imaging (MRI).

METHODS

A total of 169 patients were divided into three groups: 41 in the preservation group, 70 in the resection group, and 58 in the absent group. In the preservation group, rather than passing the graft through the remnant tissue, the graft was reconstructed such that the anteromedial and posterolateral bundles sandwiched the remnant to avoid damage to the remnant and maintain its continuity. Based on 1-year postoperative MRI, the grafts were divided into three regions: distal, middle, and proximal. The signal/noise quotient (SNQ) of each region of interest was calculated to evaluate the signal intensity of the graft and was compared among the three groups. Additionally, to identify factors influencing graft maturity, a multiple regression analysis was performed with SNQ as the dependent variable and patient demographics, bone morphology, and surgical factors as independent variables.

RESULTS

In a three-group comparison of mean SNQs, the distal region was 3.3 ± 3.4, 8.9 ± 8.3, and 9.0 ± 8.6 (p < 0.001), the middle region was 5.3 ± 3.7, 10.9 ± 11.1, and 11.3 ± 10.2 (p < 0.001), and the proximal region was 6.8 ± 4.5, 11.1 ± 8.8, and 11.7 ± 10.8 (p = 0.017), in order of the preservation, resection, and absent groups, respectively. That indicated that the remnant-preserving ACLR was more hypointense than ACLR with remnant resection or absent in all three regions. Multiple regression analysis showed that remnant preservation remained the relevant factor affecting SNQ of the graft at the distal and middle levels.

CONCLUSION

The new remnant-preserving anatomic double-bundle ACLR had significantly better graft maturity, measured by SNQ on MRI, than the remnant resection and absent groups. The remnant procedure was the relevant factor affecting graft maturity.

LEVEL OF EVIDENCE

Level III.

Magnetic Resonance Imaging Assessment of Hamstring Graft Healing and Integration 1 and Minimum 2 Years after ACL Reconstruction

BACKGROUND

An increase has been seen in the number of studies of anterior cruciate ligament reconstruction (ACLR) that use magnetic resonance imaging (MRI) as an outcome measure and proxy for healing and integration of the reconstruction graft. Despite this, the MRI appearance of a steady-state graft and how long it takes to achieve such an appearance have not yet been established.

PURPOSE

To establish whether a hamstring tendon autograft for ACLR changes in appearance on MRI scans between 1 and 2 years and whether this change affects a patient's ability to return to sports.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with hamstring tendon autograft ACLR underwent MRI and clinical outcome measures at 1 year and at a final follow-up of at least 2 years. MRI graft signal was measured at multiple regions of interest using oblique reconstructions both parallel and perpendicular to the graft, with lower signal indicative of better healing and expressed as the signal intensity ratio (SIR). Changes in tunnel aperture areas were also measured. Clinical outcomes were side-to-side anterior laxity and patient-reported outcome measures (PROMs).

RESULTS

A total of 42 patients were included. At 1 year, the mean SIR for the graft was 2.7 ± 1.2. Graft SIR of the femoral aperture was significantly higher than that of the tibial aperture (3.4 ± 1.3 vs 2.6 ± 1.8, respectively; P = .022). Overall, no significant change was seen on MRI scans after 2 years; a proximal graft SIR of 1.9 provided a sensitivity of 96% to remain unchanged. However, in the 6 patients with the highest proximal graft SIR (>4) at 1 year, a significant reduction in signal was seen at final follow-up (P = .026), alongside an improvement in sporting level. A significant reduction in aperture area was also seen between 1 and 2 years (tibial, -6.3 mm², P < .001; femoral, -13.3 mm², P < .001), which was more marked in the group with proximal graft SIR >4 at 1 year and correlated with a reduction in graft signal. The patients had a high sporting level; the median Tegner activity score was 6 (range, 5-10), and a third of patients scored either 9 or 10. Overall, PROMs and knee laxity were not associated with MRI appearance.

CONCLUSION

In the majority of patients, graft SIR on MRI did not change significantly after 1 year, and a proximal graft SIR <2 was a sensitive indicator for a stable graft signal, implying healing. Monitoring is proposed for patients who have a high signal at 1 year (proximal graft SIR >4), because a significant reduction in signal was seen in the second year, indicative of ongoing healing, alongside an improvement in sporting level. A reduction in tunnel aperture area correlated with a reduction in graft SIR, suggesting this could also be a useful measure of graft integration.