Partial ACL tears: anatomic reconstruction versus nonanatomic augmentation surgery

Clinical Results of Combined ACL and Anterolateral Ligament Reconstruction: A Narrative Review from the SANTI Study Group

Lateral extraarticular procedures (LEAPs) in the anterior cruciate ligament (ACL)-injured knee were widely abandoned in the 1990s but have seen a recent resurgence. The aim of this review was to demonstrate that anterolateral ligament reconstruction (ALLR) is associated with evidence of significant advantages and no evidence of historical concerns. A narrative review of the literature was performed. Combined ACL + ALLR is associated with improved outcomes when compared against isolated ACL reconstruction, including a significantly lower risk of ACL graft rupture (hazard ratio [HR]: 0.327, 95% CI: 0.130-0.758), a significantly lower risk of reoperation for secondary meniscectomy following medial meniscal repair at the time of ACL reconstruction (HR: 0.443, 95% CI: 0.218-0.866), significantly increased likelihood of return to the preinjury level of sport following primary (odds ratio [OR]: 1.938, 95% CI: 1.174-3.224) and revision ACL reconstruction (57.1 vs. 25.6%, respectively; p = 0.008), and in chronic ACL injuries, less residual pivot shift (9.1 vs. 35.3%, p = 0.011), and better IKDC (92.7 ± 5.9 vs. 87.1 ± 9.0, p = 0.0013) and Lysholm (95.4 ± 5.3 vs. 90.0 ± 7.1, p < 0.0001) scores, and no evidence of historical concerns. Combined ACLR + ALLR is associated with excellent clinical outcomes with no evidence of the adverse events that led to the historical widespread abandonment of other types of LEAP. Specifically, comparative series have demonstrated significant advantages of ALLR when compared against isolated ACLR with respect to reduced rates of ACL graft rupture, secondary meniscectomy, persistent instability, and significantly improved functional outcomes and improved return to sport metrics.

Management of Partial Tears of the Anterior Cruciate Ligament: A Review of the Anatomy, Diagnosis, and Treatment

Partial anterior cruciate ligament (ACL) tears comprise an estimated 10% to 27% of isolated ACL injuries. Partial ACL tears may be challenging to clinically diagnose. We reviewed relevant studies focusing on the anatomy, diagnosis, imaging, and treatment of a partial injury with the goal of providing guidance to clinicians. Although a comprehensive patient history, thorough clinical examination, and imaging studies are helpful in arriving at a diagnosis, the benchmark for diagnosis remains visualization and examination of the ACL at the time of knee arthroscopy. Currently, limited data exist about the long-term outcomes of nonsurgical treatment. Some studies demonstrate that younger, active patients have the risk of progressing to a complete ACL rupture with conservative treatment. The decision to proceed with surgery is based on careful history and physical examination findings that suggest either a "functional" or "nonfunctional" ACL. Surgical treatment consists of augmenting the intact bundle with a selective bundle reconstruction versus a traditional ACL reconstruction. Selective bundle reconstruction has limited data available but is an option. The best evidence supports traditional ACL reconstruction for the surgical management of patients with documented nonfunctional partial tears of the ACL.

Selective bundle reconstruction in partial ACL tears leads to excellent long-term functional outcomes and a low percentage of failures

BACKGROUND

The optimal treatment of partial anterior cruciate ligament (ACL) tears continues to be debatable. Short-term results of selective bundle reconstruction have already been widely shown. The purpose of this study was to assess functional outcomes, subjective satisfaction and the failure rate of selective bundle reconstructions for partial ACL tears over a five to nine year follow-up period.

METHODS

Patients who underwent ACL selective bundle reconstruction between October 2008 and October 2012 were studied. Functional assessment was performed with the objective International Knee Documentation Committee (IKDC) ligament evaluation form, the Lysholm knee scale and the Tegner activity level scale. Cumulative failure and level of satisfaction have also been investigated.

RESULTS

Seventy-six patients were included. The average follow-up period was 85 months (range 65-110). Thirty-four had AMB tear and 42 had PLB tears. An overall statistically significant improvement (p < 0.001) was obtained in terms of the subjective IKDC and the Lysholm questionnaire between preoperative and last follow-up. The same or no more than one level lower Tegner score was restored in 97.3% of the cases. Cumulative failure was observed in two patients (2.6%). Dissatisfied patient percentage was 15% (4/76).

CONCLUSIONS

Selective bundle reconstruction in partial ACL tears leads to excellent long-term functional outcomes, a low percentage of failures and a high degree of subjective satisfaction in patients.

LEVEL OF EVIDENCE

Therapeutic case series; level 4.

Clinical, functional, and isokinetic study of a prospective series of anterior cruciate ligament ligamentoplasty with pedicular hamstrings

PURPOSE

Few studies describe the specific results of anterior cruciate ligament reconstruction with pedicled hamstring graft (HG). Our goal was to report the isokinetic, clinical, and functional outcomes over the post-operative year following pedicled hamstring ligamentoplasty.

METHODS

Twenty-four patients with ACL rupture (mean age 27.4 years) were included prospectively. The technique used a four-stranded HG transplant pedicled to the tibia. The functional result (Lysholm knee score and subjective IKDC score), clinical result (KT-1000, Lachman test, joint amplitudes, objective IKDC score), and isokinetic complication occurrence were analyzed at six months and 12 months follow-up. The functional results, clinical parameters, and complications were analyzed at 30 months follow-up. The comparison of the variables with the various regressions was carried out by a Wilcoxon sign test.

RESULTS

Twenty-one patients were reviewed at six, nine, 12, and 30 months. The mean Lysholm knee score was 90/100 at six months, 96/100 at one year, and 95/100 at 30 months. The mean subjective IKDC score was 77/100 and 89/100 at six and 12 months, and 91/100 at 30 months. The mean difference in laxity compared with the healthy knee was 1.4 mm at six months, 1.9 mm at 12 months, and 2 mm at 30 months. The objective IKDC score was A or B for all patients at 12 and 30 months. The average quadriceps strength deficit decreased from 27 to 16% between six and 12 months post-operative (p = 0.0091) and the average flexor deficit from 23 to 12% (p = 0.0084). No complications were identified.

CONCLUSION

The abovementioned technique allows reaching functional, clinical, and isokinetic results comparable with the standard techniques while preserving the mechanical and biological interest of tibial insertion.

Over-the-top ACL reconstruction yields comparable outcomes to traditional ACL reconstruction in primary and revision settings: a systematic review

PURPOSE

To assess clinical outcomes of over-the-top (OTT) ACL reconstruction (ACLR) in skeletally mature patients, where physeal sparing is not a consideration. The hypothesis is that OTT will produce successful yet inferior outcomes compared to anatomic ACL approaches in both primary and revision settings.

METHODS

Two reviewers searched two online databases (EMBASE and MEDLINE) from inception to October 2017 for literature on OTT ACLR in skeletally mature patients. The systematic screening process was completed in duplicate, independently, and based on predetermined criteria. An expert in the field was consulted to resolve disagreements for full-text screening. Quality assessment of included papers was performed independently and in duplicate.

RESULTS

From 3148 initial studies, 16 eligible studies (three RCTs and 13 case series) satisfied inclusion criteria. Three focused on the revision setting. The mean age of patients undergoing primary reconstruction was 26.9 ± 3.6, with 21.3% female patients and 31.4 ± 1.2 (26.1% female) in revision settings. Of primary studies reporting return to sport (n = 151), 69% of patients returned to pre-injury sports participation, with a total 94% returning to any sports activity. In revision settings (n = 48), 52.1% of patients returned to pre-injury sports participation, 25.2% returned to a lower level and 12.5% ceased sporting activity. Primary reconstruction studies reported a mean post-operative Tegner score of 6.5 ± 0.5 (n = 181) and mean KOOS of 82.8 ± 8.1 (n = 96). Primary studies reported a total 13 graft failures (3.7%), seven of which were re-ruptures (2.0%). The revision failure rate was 8.4% (four patients).

CONCLUSION

Clinically important outcomes for OTT ACLR are comparable to literature figures for traditional all-inside, transtibial and/or anteromedial portal drilling techniques. This holds true in revision settings.

LEVEL OF EVIDENCE

IV.

"Over the Top" Augmentation for Partial Anterior Cruciate Ligament Tears Using Suspension Device for Tibial Fixation

A technique for augmentation of the partial anterior cruciate ligament is presented. The patient is positioned supine with the knee flexed 90°. After addressing intra-articular injuries, the autologous semitendinosus tendon is harvested and measured in a doubled manner; after that, the tibial tunnel is performed in the outside-in direction, of the same diameter of the doubled graft. Both ends of the graft are sutured together, after inserting it through the loop of a suspension device, which is attached in its augmentation piece. A lateral femoral incision is made, to approach the joint through the "over the top" position. A looped thread is introduced inside the joint with the aid of a hook. This thread pulls the graft's sutures through the "over the top" position. A femoral tunnel is then drilled in the lateromedial and caudocranial direction. The suspension device is attached to the anterior tibial cortex and the graft is pulled in the caudocranial direction to the femoral tunnel, where an interference screw is used for fixation.

Effects of pre-operative knee laxity on clinical outcomes after partial anterior cruciate ligament reconstruction

BACKGROUND

The effects of retaining residual bundles on surgical outcomes has not been observed, so we evaluated the effects of preoperative knee laxity on clinical outcomes after partial anterior cruciate ligament (ACL) reconstruction for partial ACL rupture in this study.

PURPOSE

To evaluate the effects of preoperative knee laxity on clinical outcomes after partial anterior cruciate ligament (ACL) reconstruction for partial ACL rupture.

METHODS

The data of 47 patients, who had partial ACL rupture and underwent partial ACL reconstruction, were retrospectively analyzed. According to preoperative kneelax arthrometer and pivot shift test, the 47 patients were divided into group A (kneelax arthrometer ≤5mm and pivot shift test <II grade, n=26) and group B (kneelax arthrometer >5mm and/or pivot shift test ≥II grade, n=21). The minimum follow-up duration lasted 2 years. The clinical outcomes were evaluated using IKDC (International Knee Documentation Committee) scoring systems, Lysholm knee scoring scale, Tegner activity rating, Lachman test, Pivot shift test and the kneelax arthrometer.

RESULTS

The function and stability examinations for the affected knee joint were significantly improved in both groups after partial ACL reconstruction as compared with preoperative ones (all P<0.01). There were no significant differences in the post-operative Lysholm and Tegner scores, Lachman and Pivot shift test results between both groups (all P>0.05). However, there were significant differences between the two groups in terms of the post-operative IKDC scoring system and kneelax arthrometer examination result (all P<0.05).

CONCLUSIONS

In the patients with partial ACL rupture, the mechanical strength of the remnant ligament has significant influence on the therapeutic effects of partial reconstruction. The patients with kneelax arthrometer >5mm and/or pivot shift test ≥II grade still have anterior instability in the affected knee after partial reconstruction.

Saphenous nerve injury during hamstring tendons harvest: Does the incision matter? A systematic review

PURPOSE

Infrapatellar branch of saphenous nerve injury is a common complication following hamstring graft harvest during anterior cruciate ligament reconstruction. The direction of skin incision performed at proximal tibial metaphysis may affect the rate of iatrogenic nerve damage. Aim of the present systematic review was to evaluate evidence that would substantiate the adoption of one incision over another for hamstring graft harvesting.

METHODS

The available literature was systematically screened searching studies dealing with iatrogenic injury to the saphenous nerve after anterior cruciate ligament reconstruction using hamstring tendons. A search was performed using the keywords "Saphenous" and "Infrapatellar branch" in combination with "Anterior cruciate ligament", "arthroscopy" and "hamstrings", supplying no limits regard the publication year. Coleman methodological score was performed in all the retained articles.

RESULTS

Five articles matched the inclusion criteria. There were two randomized controlled trials, one prospective comparative study and two retrospective comparative series. Poor methodological quality was found overall. A vertical incision was found to significantly affect the presence of hypoesthesia and the extent of the area of sensory loss in three articles; no difference was registered in one, and a trend towards a lower rate of iatrogenic nerve damage using an oblique incision was found in the remaining one, without any statistical significance.

CONCLUSION

Although the low methodological quality of the analysed studies does not permit to draw definitive conclusions, the anatomical course of the nerve along with the results obtained in the available studies seems to suggest lower rate of neurological impairment adopting an oblique incision. This kind of incision may therefore be preferred in the routine clinical practice.

LEVEL OF EVIDENCE

Systematic review, Level II.

Single-Bundle Augmentation for a Partial Tear of the Anterior Cruciate Ligament

Given the prevalence of anterior cruciate ligament (ACL) tears in young athletes, it is essential to elucidate and illustrate surgical interventions that return the most favorable outcomes. Although most ACL injuries are full-thickness tears, occasionally either the anteromedial (AM) or posterolateral (PL) bundle is torn in isolation, allowing consideration of an ACL reconstruction or augmentation. Because the ACL-deficient knee has been shown to exhibit less proprioceptive feedback, the preservation of the intact bundle may offer an inherent component of stability. After arthroscopy has confirmed a partial ACL tear, the decision to augment the intact bundle can be made. The technique is adapted from principles of the double-bundle reconstruction such that the graft follows the path of either the native AM bundle or the native PL bundle, depending on the location of the partial tear. We present our surgical technique for ACL AM bundle augmentation with PL bundle reconstruction using a semitendinosus tendon autograft.

Short term results of anterior cruciate ligament augmentation in professional and amateur athletes

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction is a widely accepted procedure; however, controversies exist about ACL augmentation. The purpose of this study was to assess the clinical outcomes of ACL augmentation in professional and amateur athletes with isolated single bundle ACL tears.

MATERIALS AND METHODS

A consecutive series of professional and amateur athletes with partial ACL tears who underwent selective bundle reconstruction were analyzed. Stability was assessed with the Lachman test, anterior-drawer test, pivot-shift test and KT-1000 arthrometer. Functional assessment was performed using the subjective Lysholm questionnaire.

RESULTS

Fifty-six patients were enrolled. The mean follow-up period was 19.3 months. All patients had posterolateral bundle (PLB) tears, and no anteromedial bundle (AMB) tears were found. The Lysholm score improved significantly from 78 (SD = 2.69) preoperatively to 96 (SD = 3.41) postoperatively (P value <0.0001). The pivot-shift test, Lachman test and anterior-drawer test results were negative in all cases postoperatively. Anterior tibial translation from neutral was 4.9 mm (SD = 2.7) preoperatively, and decreased significantly to 2.1 (SD = 0.6) postoperatively, measured with a KT-1000 arthrometer (P value <0.00001).

CONCLUSION

In this study, we showed that ACL augmentation had good results in symptomatic professional and amateur athletes, and although further studies are needed to investigate long-term results, we recommend this surgery for all symptomatic athletic patients, especially those who would like to maintain an active lifestyle. Level of evidence IV.

Hamstring graft tibial insertion preservation versus detachment in anterior cruciate ligament reconstruction: a prospective randomized comparative study

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction with hamstring graft (HG) is a commonly performed procedure. Despite the type of reconstruction chosen, the detached HG undergoes a remodeling process known as ligamentization. In order to shorten the ligamentization process, the maintenance of HG tibial insertion, aimed to spare the tendons vascular supply, has been postulated. The aim of this paper is to report the results of a prospective randomized study comparing clinical and MRI results between two different ACL reconstructive procedures with and without HG tibial insertion preservation.

METHODS

Forty patients (mean age 27.5 ± 9.5 years) were enrolled and randomly divided into two groups. The study group underwent an ACL reconstruction using a distally inserted HG, while the control group underwent a technique encompassing HG tibial detachment. Subjective and objective IKDC score was administered preoperatively and at 3-, 6-, 12- and 24-month follow-up. Graft morphology was assessed through MRI evaluation performed at 6-month follow-up.

RESULTS

Clinical results were excellent in both groups. Regarding MRI results, a better intra-articular graft morphology was observed in the study group (Tau = 0.313, p = 0.024). No differences in graft integration were noticed.

CONCLUSION

The main finding of this preliminary study is that preservation of the hamstring tibial insertion seems to enhance graft ligamentization with improved morphology of the intra-articular portion of the graft compared to a detachment of the hamstring tendons from the tibial side. Further well-designed studies with higher number of patients as well as more serial MRI evaluations are required to validate these preliminary findings.

Anterior cruciate ligament - updating article

This updating article on the anterior cruciate ligament (ACL) has the aim of addressing some of the most interesting current topics in this field. Within this stratified approach, it contains the following sections: ACL remnant; anterolateral ligament and combined intra and extra-articular reconstruction; fixation devices; and ACL femoral tunnel creation techniques.

Biomechanical study of ACL reconstruction grafts

There are no published studies describing the strength quadrupled gracilis tendon alone and quadrupled semitendinosus tendon alone in the configuration used for anterior cruciate ligament (ACL) reconstruction. The primary objective was to compare the mechanical properties of grafts used for ACL reconstruction during a tensile failure test. The secondary objective was to evaluate the effect of uniform suturing on graft strength. Fifteen pairs of knees were used. The mechanical properties of five types of ACL grafts were evaluated: patellar tendon (PT), sutured patellar tendon (sPT), both hamstring tendons (GST4), quadrupled semitendinosus (ST4), and quadrupled gracilis (G4). Validated methods were used to perform the tensile tests to failure and to record the results. Student's t-test was used to compare the various samples. The maximum load to failure was 630.8N (± 239.1) for the ST4, 473.5N (± 176.9) for the GST4, 413.3N (± 120.4) for the sPT, and 416.4N (± 187.7) for the G4 construct. Only the ST4 had a significantly higher failure load than the other grafts. The sPT had a higher failure load than the PT. The ST4 construct had the highest maximum load to failure of all the ACL graft types in the testing performed here. Uniform suturing of the grafts improved their ability to withstand tensile loading.

Preservation of hamstring tibial insertion in anterior cruciate ligament reconstruction: a review of the current literature

Hamstring graft (HG) used in anterior cruciate ligament (ACL) reconstruction undergoes a biological modification process called "ligamentization" in the early postoperative period that proceeds through three different phases: an early graft-healing phase with central graft necrosis, a phase of proliferation, and finally, a ligamentization phase toward the properties of the intact ACL. The fastening of this process could result in more aggressive rehabilitation protocols as well as faster sport resumption. A recent literature supports the preservation of HG tibial attachment in order to enhance "ligamentization" process. Aim of this literature review is to describe all the techniques described that spare HG tibial insertion and the obtained results in order to evaluate evidence that would substantiate the maintenance of HG tibial insertion in ACL reconstruction. A search was performed using the following keywords "ACL reconstruction" in combination with "hamstrings," "hamstrings insertion," "tibial insertion," "ligamentization," and "over the top"; 18 articles were found to be relevant. Among these, eight randomized clinical trials (RCTs) were found. The RCT analyzed presented a high number of biases regarding the analyzed topic, thus making impossible to draw definitive evidences to validate HG tibial insertion sparing in ACL reconstruction. Despite the satisfactory results in many clinical series and the promising results in anatomic and animal studies, well-designed prospective clinical trials with large cohort of patients associated with MRI evaluation are mandatory to assess the beneficial effects of HG attachment preservation in ACL reconstruction.

Over-the-Top Anterior Cruciate Ligament Reconstruction Using Single- or Double-Strand Hamstrings Autograft

The purpose of this study is to (1) report the long-term clinical and radiographic outcomes of a nonanatomical anterior cruciate ligament (ACL) reconstruction using an over-the-top (OTT) femoral route and (2) compare single-strand (1SHG) and double-strand (2SHG) hamstrings graft reconstruction. Fifty-one consecutive patients (mean age, 29.2±3.8 years) underwent nonanatomical ACL reconstruction using OTT femoral passage. Twenty patients underwent 1SHG reconstruction and 31 underwent 2SHG reconstruction. International Knee Documentation Committee (IKDC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner score, and KT-1000 (Medmetric Corporation, San Diego, California) evaluation were recorded at a mean follow-up of 12.1±1.6 years. At final follow-up, radiographic evaluation was performed according to the IKDC grading system. Mean IKDC subjective score at follow-up was 76.6±21.9 in the 1SHG group and 88.9±10.0 in the 2SHG (P=.009). Average KOOS was 82.6±18.7 in the 1SHG group and 92.4±9.2 in the 2SHG group (P=.016). Objective IKDC evaluation showed a higher percentage of normal knees in the 2SHG group (P=.018). Pivot shift testing revealed a significantly higher number of normal knees in the 2SHG group (P=.001). Radiographs showed fewer degenerative changes in the 2SHG group at final follow-up in the medial (P=.01) and lateral (P=.037) compartments. Nonanatomical ACL reconstruction using the OTT technique provided satisfactory results in terms of control of both static and dynamic instability at long-term follow-up, thus preventing degenerative joint disease. The 2SHG group showed better subjective and functional outcomes with fewer degenerative changes compared with the 1SHG group at long-term follow-up.

Partial tearing of the anterior cruciate ligament: diagnosis and treatment

Partial tears of the anterior cruciate ligament (ACL) are common and represent 10–27% of the total. The main reasons for attending to cases of non-torn bundles are biomechanical, vascular and proprioceptive. Continued presence of the bundle also serves as protection during the healing process. There is controversy regarding the definition of these injuries, which is based on anatomy, clinical examination, translation measurements, imaging examinations and arthroscopy. The way in which it is treated will depend on the existing laxity and instability. Conservative treatment is optional for cases without instability, with a focus on motor rehabilitation. Surgical treatment is a challenge, since it requires correct positioning of the bone tunnels and conservation of the remnants of the torn bundle. The pivot shift test under anesthesia, the magnetic resonance findings, the previous level and type of sports activity and the arthroscopic appearance and mechanical properties of the remnants will aid the orthopedist in the decision-making process between conservative treatment, surgical treatment with strengthening of the native ACL (selective reconstruction) and classical (anatomical) reconstruction.

Updates in biological therapies for knee injuries: anterior cruciate ligament

There have been many advances in anterior cruciate ligament reconstruction (ACLR) techniques incorporating biological treatment. The aim of this review is to discuss the recent contributions that may enlighten our understanding of biological therapies for anterior cruciate ligament (ACL) injuries and improve management decisions involving these enhancement options. Three main biological procedures will be analyzed: bio-enhanced ACL repair, bio-enhanced ACLR scrutinized under the four basic principles of tissue engineering (scaffolds, cell sources, growth factors/cytokines including platelet-rich plasma, and mechanical stimuli), and remnant-preserving ACLR. There is controversial information regarding remnant-preserving ACLR, since different procedures are grouped under the same designation. A new definition for remnant-preserving ACLR surgery is proposed, dividing it into its three major procedures (selective bundle augmentation, augmentation, and nonfunctional remnant preservation); also, an ACL lesion pattern classification and a treatment algorithm, which will hopefully standardize these terms and procedures for future studies, are presented.