ACL suturing using dynamic intraligamentary stabilisation showing good clinical outcome but a high reoperation rate: a retrospective independent study

Manipulation Under Anesthesia and Lysis of Adhesions Are the Most Commonly Reported Treatments for Arthrofibrosis of the Knee After Arthroscopy or Anterior Cruciate Ligament Reconstruction in Both Pediatric and Adult Patients

Purpose

To systematically review the literature and provide a detailed summary of the current treatments and outcomes for arthrofibrosis following knee arthroscopy and anterior cruciate ligament reconstruction (ACLR) and to compare the treatment strategies in pediatric and adult populations.

Methods

A systematic review was performed in March 2022 using PubMed, EMBASE, and Cochrane Library Databases per Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Search terms consisted of variations of the following: ("arthrofibrosis" OR "stiffness" OR "stiff" OR "complications") AND ("arthroscopy" OR "arthroscop" OR "ACL" OR "anterior cruciate") AND ("treat" OR "care" OR "management" AND "knee"). The inclusion criteria were studies that were written in English, were published since 2000, and that reported outcomes of knee arthroscopy or ACLR for treatment of arthrofibrosis of the knee. The study quality was assessed, and data about the patients and treatments were recorded. Treatments were compared between pediatric and adult patients.

Results

A total of 1,208 articles were identified in the initial search, 42 (3.48%) of which met eligibility criteria, involving treatment regimens for arthrofibrosis following knee arthroscopy or ACLR. Of the 42 studies included, 29 (69.0%) were reported data for adults and 13 (31.0%) reported data for pediatric patients. Thirty-nine studies (92.8%) discussed manipulation under anesthesia and/or lysis of adhesions (LOA) as treatment for arthrofibrosis of the knee, whereas 2 (4.8%) described the use of medications.

Conclusions

Within orthopaedic sports medicine literature, there is variability in the reported treatment options for arthrofibrosis of the knee. Most studies identified manipulation under anesthesia and/or LOA as the treatment among both adult and pediatric patients. Other variants include notchplasty, open posterior arthrolysis, total graft resection, removal of hardware with LOA, dynamic splinting, casting in extension, bracing, and medications.

Level of Evidence

Level IV, systematic review of Level I-IV studies.

Prevention of knee stiffness following ligament reconstruction: Understanding the role of Arthrogenic Muscle Inhibition (AMI)

The knee is a joint that is often injured in sport, with a large and increasing number of ligament tears and repairs; postoperative complications can lead to poor outcome, such as stiffness. Beyond the well-known and well-described intra- and extra-articular causes of postoperative stiffness, the present study introduces the concept of a central reflex motor inhibition mechanism called arthrogenic muscle inhibition (AMI). AMI occurs after trauma and can be defined as active knee extension deficit due to central impairment of Vastus Medialis Obliquus (VMO) contraction, often associated with spinal reflex hamstring contracture. This explains the post-traumatic flexion contracture that is so common after knee sprain. The clinical presentation of AMI is easy to detect in consultation, in 4 grades from simple VMO inhibition to fixed flexion contracture by posterior capsule retraction in chronic cases. After recent anterior cruciate ligament (ACL) tear, more than 55% of patients show AMI, reducible in 80% of cases by simple targeted exercises initiated in consultation. Practically, in patients who have sustained knee sprain, it is essential to screen for this reflex mechanism and assess reducibility, as AMI greatly aggravates the risk of postoperative stiffness. In case of hemarthrosis, we recommend joint aspiration, which provides immediate benefit in terms of pain and motor inhibition. In case of persistent AMI, classical electrostimulation and "cushion crush", as used by all physiotherapists, are ineffective. To reduce the risk of postoperative stiffness, no surgery should be considered until AMI has resolved. LEVEL OF EVIDENCE: expert opinion.

Comparison of Clinical Outcomes Between Modern Augmented ACL Repair and Autograft ACL Reconstruction: A Systematic Review and Meta-analysis of Studies With Minimum 2-Year Follow-up

Background

Anterior cruciate ligament (ACL) reconstruction has been the gold standard for primary ACL rupture since the 1990s. In the past decade, ACL repair has received renewed attention and increased research.

Purpose

To compare the clinical outcomes of modern augmented ACL repair versus autograft reconstruction for ACL ruptures.

Study Design

Systematic review; Level of evidence, 3.

Methods

A search of the PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library databases was conducted for prospective or retrospective comparative studies published between January 1, 2010, and January 3, 2023, with a minimum 2-year follow-up. Two independent reviewers performed data extraction and methodological quality assessment. Sensitivity analysis was performed to maintain the stability of results.

Results

Nine studies were included (minimum follow-up period, 24-60 months). The total sample size was 833 patients (augmented repair group: 358 patients; autograft ACL reconstruction group: 475 patients). There were 4 randomized controlled trials (level 1), 1 prospective comparative study (level 2), 2 retrospective comparative studies (level 3), and 2 case-control studies (level 3). The augmented ACL repair group attained significantly higher Lysholm score (weighted mean difference [WMD] = 1.57; 95% confidence interval [CI], 0.14-3.01; P = .03) and hamstring strength (WMD = 36.69; 95% CI, 29.07-44.31; P < .01) but had higher rates of hardware removal (odds ratio [OR] = 6.30; 95% CI, 2.44-16.23; P = .0001), reoperation (OR = 1.87; 95% CI, 1.33-2.62; P = .0003), and failure (OR = 1.58; 95% CI, 1.03-2.43; P = .0003) compared with the autograft ACL reconstruction group. No significant differences were observed between the repair and reconstruction groups regarding postoperative International Knee Documentation Committee scores, Tegner scores, knee laxity, satisfaction, ACL revisions, complications, and reoperation rather than revision.

Conclusion

Augmented ACL repair was associated with higher rates of reoperation, hardware removal, and failure compared with autograft ACL reconstruction in studies with minimum 2-year follow-up data. However, augmented ACL repair had higher Lysholm scores and hamstring strength versus autograft ACL reconstruction.

Return to Sports After ACL Augmentation With Anterolateral Reconstruction (ALR) Harvesting Gracilis Only Compared With ACL Reconstruction With ALR Harvesting Both Hamstring Tendons

BACKGROUND

Anterior cruciate ligament (ACL) repair (ACL-Rp) is known to be a valuable alternative to ACL reconstruction (ACL-Rc) in selected indications. The majority of the ACL-Rp techniques recommend the use of a synthetic brace. The use of the gracilis allows both a biological internal brace and anterolateral ligament reconstruction (ALR).

PURPOSE

The primary objective was to compare the early ability to return to sports between patients who underwent ACL-Rp using a gracilis autograft as an internal brace augmentation with ALR and patients who underwent the conventional ACL-Rc with ALR technique sacrificing both the gracilis and the semitendinosus. The secondary objective was to compare the failure rate, clinical scores, and return to sports at a minimum follow-up of 2 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective analysis was undertaken. A total of 49 patients who underwent ACL-Rp with ALR between December 2018 and May 2019 were propensity matched at a 1:1 ratio to those who underwent ACL-Rc with ALR during the same period. The decision to perform ACL-Rp with ALR was based on preoperative selection and intraoperative arthroscopic findings: proximal avulsion tear, partial ACL tear, low- to midlevel sports participation, and good tissue quality. The ability to return to sports was assessed using isokinetic tests and the Knee Santy Athletic Return to Sport test functional test at 6 months postoperatively. At the final follow-up, knee laxity parameters, return to sports, and clinical outcome (Lysholm score, Tegner Activity Scale score, International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Anterior Cruciate Ligament-Return to Sport after Injury score) were recorded.

RESULTS

The ACL-Rp group had significantly less hamstring strength deficit when compared with their counterparts who underwent ACL-Rc (0.2% vs 10.2% in concentric, P < .001; 2.5% vs 14% in eccentric, P < .001). The mean Knee Santy Athletic Return to Sport test score was significantly higher in the ACL-Rc group (69.7% ± 16.6% [range, 19%-100%] vs 61% ± 16.8% [range, 19%-100%]; P = .001). In the ACL-Rp group, 61% (30/49) of the patients were authorized to return to pivot sports versus 41% (20/49) in the ACL-Rc group (P = .04). At a mean final follow-up of 31.4 ± 3.5 months, no significant differences were demonstrated between groups with respect to clinical scores and knee laxity parameters. There was a trend for a higher failure rate in the ACL-Rp group without any significance (ACL-Rp: 6.1% [3/49] vs ACL-Rc: 0%; P = .08).

CONCLUSION

At 6 months after operation, harvesting only the gracilis with this ACL-Rp and augmentation with ALR technique was linked to a better early ability to return to sports compared with the ACL-Rc with ALR technique harvesting both the gracilis and semitendinosus. This technique had a limited effect on early flexion strength and provided a satisfactory rerupture rate.

Mimicking the Graded Wavy Structure of the Anterior Cruciate Ligament

Anterior cruciate ligament (ACL) is the connective tissue providing mechanical stability to the knee joint. ACL reconstruction upon rupture remains a clinical challenge due to the high mechanical properties required for proper functioning. ACL owes its outstanding mechanical properties to the arrangement of the extracellular matrix (ECM) and to the cells with distinct phenotypes present along the length of the tissue. Tissue regeneration appears as an ideal alternative. In this study, a tri-phasic fibrous scaffold that mimics the structure of collagen in the native ECM is developed, presenting a wavy intermediate zone and two aligned uncurled extremes. The mechanical properties of the wavy scaffolds present a toe region, characteristic of the native ACL, and an extended yield and ultimate strain compared to aligned scaffolds. The presentation of a wavy fiber arrangement affects cell organization and the deposition of a specific ECM characteristic of fibrocartilage. Cells cultured in wavy scaffolds grow in aggregates, deposit an abundant ECM rich in fibronectin and collagen II, and express higher amounts of collagen II, X, and tenomodulin as compared to aligned scaffolds. In vivo implantation in rabbits shows a high cellular infiltration and the formation of an oriented ECM compared to aligned scaffolds.

Early Complication Analysis of Dynamic Intraligamentary Stabilization versus Anterior Cruciate Ligament Reconstruction

PURPOSE

Both dynamic intraligamentary stabilization (DIS) and reconstruction (RECO) are common treatment methods for anterior cruciate ligament (ACL) rupture. We report short term outcomes after DIS (Ligamys, Mathys, Bettlach, Switzerland) and RECO using semitendinosus tendon. We compared postoperative complications, deficits of range-of-motion (ROM), and revision rates between the two treatment options.

METHODS

A total of 690 patients (437 male, 253 female), after either DIS or RECO, were included. Of these, 147 patients (21%) received DIS and 543 (79%) underwent RECO. Follow-up examination focused on clinical examination, complications and revision rates. Anteroposterior instability and ROM deficits were analyzed in order to evaluate our policy of early intervention for all cases of ROM restrictions.

RESULTS

Relevant ROM restrictions occurred at a significantly higher rate after DIS than after RECO (4.8% vs. 1.3%; p = 0.008). Flexion was more restricted after DIS than RECO (110° vs. 124°, p < 0.001). Extension deficits also occurred more frequently after DIS compared to RECO (49.7% vs. 24.5%; p < 0.001). Total revision surgery rate was 9.1%, with patients after DIS being significantly more frequently affected (20.4% vs. 6.1%; p < 0.001).

CONCLUSIONS

Our findings indicate a significantly higher risk for ROM restriction after DIS compared to RECO, resulting in a significantly higher revision rate.

Clinical outcomes in dynamic intraligamentary stabilization technique for anterior cruciate ligament tear: A meta-analysis

BACKGROUND

To compare the clinical outcome between dynamic intraligamentary stabilization (DIS) and anterior cruciate ligament (ACL) reconstruction in ACL tears.

METHODS

PubMed, the Cochrane Library, and Embase databases were searched to identify published articles on clinical studies comparing DIS versus ACL reconstruction. The results of the eligible studies were analyzed in terms of anteroposterior knee laxity translation (ΔATT) between the injured and contralateral knees, and subjective International Knee Documentation Committee (IKDC), Lysholm score, Tegner score, and ipsilateral ACL failure, implant removal, and ACL revision.

RESULTS

Five clinical studies including 429 patients with ACL tears met the inclusion criteria. DIS showed statistically comparable outcomes of ΔATT (P = .12), IKDC (P = .38), Tegner (P = .82), ACL failure (P = .50), ACL revision (P = .29) with ACL reconstruction. A significantly higher rate of implant removal (odds ratio for DIS vs ACL reconstruction, 7.73; 95% confidence interval [CI], 2.72-22.00; P = .0001) but statistically higher Lysholm score (mean difference between DIS and ACL reconstruction, 1.59; 95% CI, 0.24-2.93; P = .02) were found in DIS group.

CONCLUSION

Five clinical studies including 429 patients with ACL tears met the inclusion criteria. DIS showed statistically comparable outcomes of ΔATT (P = .12), IKDC (P = .38), Tegner (P = .82), ACL failure (P = .50), ACL revision (P = .29) with ACL reconstruction. A significantly higher rate of implant removal (odds ratio for DIS vs ACL reconstruction, 7.73; 95% CI, 2.72-22.00; P = .0001) but statistically higher Lysholm score (mean difference between DIS and ACL reconstruction, 1.59; 95% CI, 0.24-2.93; P = .02) were found in DIS group.

Failure of primary ACL repair with dynamic intraligamentary stabilization may result in a high risk of two-stage ACL reconstruction: a case series of ten patients

PURPOSE

Dynamic Intraligamentary Stabilization (DIS) is a technique for the repair of acute anterior cruciate ligament (ACL) injuries. The purpose of this study was to investigate the potential challenges of ACL reconstruction (ACLR) following failure of DIS.

METHODS

A retrospective analysis of patients with failure of primary ACL repair performed with DIS was undertaken. Failure was defined as abnormal knee laxity (positive Lachman and/or pivot shift) and/or severely restricted range of motion. Medical and surgical records were reviewed and preoperative standard anteroposterior and lateral X-rays were assessed.

RESULTS

Between July 2015 and May 2022, 10 patients (3 males, 7 females, median age 28 years, range 18-52 years) with failure of DIS were referred to and surgically treated at a single centre. In four patients, single-stage ACLR was performed following the removal of the tibial monoblock. In six patients, arthrofibrosis and excessive tibial tunnel enlargement following the removal of the monoblock prevented single-stage ACLR. These patients underwent arthroscopic arthrolysis and tibial tunnel bone grafting as a first-stage revision procedure.

CONCLUSION

In the present case series, single-stage ACLR was performed in only four (40%) of ten patients following failure of ACL repair with DIS. Arthrofibrosis and excessive tibial tunnel enlargement following the removal of the monoblock prevented single-stage ACLR in six (60%) patients. It is important for clinicians to inform patients that, in the event of failure of ACL repair with DIS, they may run a high risk of undergoing two-stage ACLR.

LEVEL OF EVIDENCE

Level IV, Case Series.

Collagen wrapping and local platelet-rich fibrin do not improve the survival rates of ACL repair with dynamic intraligamentary stabilization: a retrospective case series after ≥5 years postoperatively

PURPOSE

Anterior cruciate ligament (ACL) repair has been recommended as a treatment principle for ACL tears. Several authors have advocated a potential role for primary repair techniques in the ACL decision tree. However, long-term results have been controversial. This study aims to determine the survival of the primarily repaired ACL after dynamic intraligamentary stabilization (DIS) with and without augmentation.

METHODS

Between 2014 and 2019, 102 patients with isolated proximal ACL ruptures underwent DIS repair within 21 days from injury and were available for follow-up either clinically or telephonically after ≥5 years postoperatively. In 45 cases, DIS repair was augmented with collagen fleece wrapping, platelet-rich fibrin (PRF) or both. Failure was defined as traumatic re-rupture or conversion to ACL reconstruction. The patients being available for physical examination underwent a.-p. stability measurement with a KT-1000 device. Functional outcome was measured with the IKDC, Tegner and Lysholm scores. Kaplan-Meier survival analysis, Log-Rank Test and Binominal logistic regression were performed.

RESULTS

After a minimum 5-year follow-up, 71/102 (69.6%) DIS repairs were not re-reptured and clinically and/or subjectively stable. Augmentation did not improve survival rates (p = 0.812). The identified factors influencing failure were a younger age and a pre-injury Tegner activity level of ≥7. 95.7% of those patients with an intact ACL repair had normal or near normal knee function based on the IKDC scoring system.

CONCLUSIONS

The 5-year overall survival rate of DIS was 69.6%. Collagen fleece wrapping and local PRF application did not improve survival. Patients not suffering failure of repair demonstrated high satisfaction. Nevertheless, the results are inferior to those of established ACL reconstruction procedures.

LEVEL OF EVIDENCE

Case series, Level IV.

Acute Anterior Cruciate Ligament Rupture: Repair or Reconstruction? Five-Year Results of a Randomized Controlled Clinical Trial

BACKGROUND

High-level evidence for short-term outcomes of contemporary anterior cruciate ligament (ACL) suture repair (ACLSR) in comparison with those of ACL reconstruction (ACLR) is scarce. High-level evidence for mid- and long-term results is lacking, whereas outcomes of ACLSR in several historical studies were shown to deteriorate at midterm follow-up after initial good short-term outcomes.

HYPOTHESIS

Contemporary ACLSR is noninferior to ACLR in the treatment of acute ACL rupture in terms of patient self-reported outcomes at 5 years postoperatively.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 48 patients were enrolled in the study and, after stratification and randomization, underwent either dynamic augmented (DA) ACLSR or anatomic single-bundle ACLR. The primary outcome measure was the International Knee Documentation Committee 2000 (IKDC) subjective score (IKDCs). Furthermore, the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale score (TAS), visual analog scale score for satisfaction (VASs), IKDC physical examination score (IKDCpe), limb symmetry index for quadriceps (LSIq) and hamstrings (LSIh) strength and jump test battery (LSIj), Kellgren-Lawrence grade of osteoarthritis (OA), and rate of adverse events were recorded. Analyses were based on an intention-to-treat principle.

RESULTS

The lower limit of the 2-sided 95% CI for the median IKDCs of the DA ACLSR group (n = 23; 75.9) was lower than the prespecified noninferiority margin (n = 21; 86.6). Therefore, the null hypothesis was rejected. However, the upper limit of the 2-sided 95% CI of the DA ACLSR group (100.0) was higher than the median IKDCs of the ACLR group (96.6), rendering the result for noninferiority inconclusive. No statistical difference was found between groups for median IKDCs (repair, 90.2; reconstruction, 96.6). Furthermore, no statistically significant differences were found for any of the secondary outcome measures for the DA ACLSR compared with the ACLR group: KOOS Symptoms, 92.9 versus 96.4; KOOS Pain, 100 versus 97.2; KOOS Activities of Daily Living, 100 versus 100; KOOS Sport and Recreation, 85.0 versus 100; TAS score, 7.0 versus 6.5; VASs, 9.2 versus 8.7; IKDCpe, 81.8% versus 100%; LSIq, ≥91.6 versus ≥88.2; LSIh, ≥95.1 versus ≥90.7; LSIj, ≥94.2 versus ≥97.6; OA grade 0, 90.9% versus 77.8%; clinical ACL failure rate, 20.8% versus 27.2%; and repeat surgery rate, 37.5% versus 20.0%, respectively.

CONCLUSION

It remains inconclusive whether the effectiveness of DA ACLSR is noninferior to that of ACLR in terms of subjective patient-reported outcomes as measured using the IKDCs. Although DA ACLSR may be a viable treatment option for patients with acute ACL rupture, caution must be exercised when considering this treatment for young, active patients, corresponding to the present study population.

Biological enhancement methods may be a viable option for ACL arthroscopic primary repair - A systematic review

BACKGROUND

Bioactive factors combined with advanced anterior cruciate ligament (ACL) primary repair technology have been used to treat ACL repairs. The current review was conducted to identify whether biological enhancement could enable superior clinical outcome, including side-to-side difference, failure rate, reoperation rate and subjective scores.

HYPOTHESIS

The implementation of ACL primary repair with biological enhancement will provide better clinical outcomes in terms of side-to-side differences, failure rate, reoperation rate and subjective scores than ACL primary repair alone.

MATERIALS AND METHODS

A systematic literature review was performed following PRISMA guidelines by searching all studies reporting outcomes of arthroscopic primary repair with or without biological augmentation published until April 19, 2020, in Medline, PubMed, Embase and the Cochrane Library. Primary metrics were side-to-side differences, failure rate and reoperation rate, as well as measurements of patient-reported outcomes at the last follow-up.

RESULTS

A total of 20 studies were finally included in this work, of which 3 were Grade I (15%), 3 studies were Grade III (15%), and 14 studies were Grade IV (70%) in terms of the level of evidence. There were 729 patients with a mean age of 30 (range: 8-68) years, and the mean follow-up period of which was 38 (range: 3-122) months. At the final follow-up, the postoperative side-to-side differences (the proportion of patients with a side-to-side difference less than 3mm) and patient-report outcomes were significantly better in the biological enhancement group. Nevertheless, there were no significant differences between the two groups in the rate of surgical failure, the rate of revision, or the positive Lachman test or pivot shift test.

CONCLUSION

Biologically enhanced arthroscopic ACL primary repair was superior to ACL primary repair alone in terms of postoperative side-to-side differences (proportion of patients with a side-to-side difference less than 3mm) and patient-reported outcomes. Thus, biologically enhanced arthroscopic ACL primary repair can be preferentially recommended over ACL arthroscopic primary repair alone.

LEVEL OF EVIDENCE

IV, systematic review.

Anterior cruciate ligament repair with internal brace augmentation: A systematic review

BACKGROUND

Primary repair of anterior cruciate ligament (ACL) ruptures has re-emerged as a treatment option for proximal tears, with internal brace augmentation often utilised. The aim of this study is to provide an overview of the current evidence presenting outcomes of ACL repair with internal bracing to assess the safety and efficacy of this technique.

METHODS

All studies reporting outcomes of arthroscopic primary repair of proximal ACL tears, augmented with internal bracing from 2014-2021 were included. Primary outcome was failure rate and secondary outcomes were subjective patient reported outcome measures (PROMs) and objective assessment of anteroposterior knee laxity.

RESULTS

Nine studies were included, consisting of 347 patients, mean age 32.5 years, mean minimum follow up 2 years. There were 36 failures (10.4%, CI 7.4% - 14.1%). PROMs reporting was variable across studies. KOOS, Lysholm and IKDC scores were most frequently used with mean scores > 87%. The mean Tegner and Marx scores at follow-up were 6.1 and 7.8 respectively. The mean side to side difference measured for anteroposterior knee laxity was 1.2mm.

CONCLUSIONS

This systematic review with meta-analysis shows that ACL repair with internal bracing is a safe technique for treatment of proximal ruptures, with a failure rate of 10.4%. Subjective scores and clinical laxity testing also revealed satisfactory results. This suggests that ACL repair with internal bracing should be considered as an alternative to ACL reconstruction for acute proximal tears, with the potential benefits of retained native tissue and proprioception, as well as negating the need for graft harvest.

ACL Repair: A Game Changer or Will History Repeat Itself? A Critical Appraisal

Until the past decade the common thought was that the anterior cruciate ligament (ACL) was not able to heal and restore knee stability. In this manuscript a brief review of studies of the developers and the early adaptors of four different modern ACL repair techniques are presented. The present status and considerations for the future of ACL repair and its research are shared. After promising short- to midterm ACL healing results by the developers, the results of the early adaptors show more variety in terms of rerupture and reintervention for other reasons. Risk factors for failure are a young age, high preinjury sports activity level, midsubstance ruptures and impaired integrity of the ACL bundles and the synovial sheath. There is a call for more clinical data and randomized clinical trials. Conclusion: an important finding of the past decade is that the ACL is able to heal and subsequently restabilize the knee. Patient selection is emphasized: the ideal patient is a non-high athlete older than 25 and has an acute proximal one bundle ACL rupture. Further research will have to show if ACL repair could be a game changer or if history will repeat itself.

Knotless Primary Anterior Cruciate Ligament Repair with Adjustable Loop Device and Internal Brace Augmentation

With the recent resurgence of primary anterior cruciate ligament repair, it is important to strive for optimal patient outcomes. This knotless primary repair procedure takes advantage of the use of an adjustable loop device, which allows for intraoperative retensioning by the surgeon. This technical advancement combined with augmentation with an internal brace could potentially minimize gap formation at the repair site, thereby increasing repair stability and ultimate outcome.

Efficacy of Nonaugmented, Static Augmented, and Dynamic Augmented Suture Repair of the Ruptured Anterior Cruciate Ligament: A Systematic Review of the Literature

BACKGROUND

Anterior cruciate ligament suture repair (ACLSR) was abandoned late last century in favor of anterior cruciate ligament (ACL) reconstruction (ACLR) because of overall disappointing results. However, in recent years there has been renewed and increasing interest in ACLSR for treatment of ACL ruptures. Several contemporary ACLSR techniques are being used, but any difference in effectiveness is unclear.

HYPOTHESIS

Contemporary nonaugmented (NA), static augmented (SA), and dynamic augmented (DA) ACLSR leads to (1) comparable outcomes overall and (2) comparable outcomes between proximal third, middle third, and combined ACL rupture locations (a) within and (b) between ACLSR technique categories.

STUDY DESIGN

Systematic review.

METHODS

An electronic search was performed in the MEDLINE and Embase databases for the period between January 1, 2010, and August 7, 2019. All articles describing clinical and patient-reported outcomes for ACLSR were identified and included, and outcomes for NA, SA, and DA ACLSR categories were compared.

RESULTS

A total of 31 articles and 2422 patients were included. The majority of articles (65%) and patients (89%) reported outcomes of DA ACLSR. Overall, there was high heterogeneity in study characteristics and level as well as quality of evidence (19 level 4; 7 level 3; 3 level 2; and 2 level 1). Most studies indicated excellent patient-reported outcomes. Overall, the variability in (and the maximum of) the reported failure rate was high within all ACLSR categories. The variability in (and the maximum of) the reported rate of all other complications was highest for DA ACLSR. Regarding ACL rupture location, the failure rate was highest in proximal ACL ruptures within the SA and DA ACLSR categories; rates of all other reported complications were highest in combined ACL ruptures within the DA ACLSR category. However, no studies in the NA category and only 1 study in the SA ACLSR category evaluated combined ACL ruptures. The majority of studies comparing ACLSR and ACLR found no differences in outcomes.

CONCLUSION

The amount of high-quality evidence for contemporary ACLSR is poor. This makes it difficult to interpret differences among ACLSR categories and among ACL rupture locations and, though promising, to establish the role of ACLSR in the treatment of ACL ruptures. More high-quality large randomized clinical trials with longer follow-up comparing ACLSR and ACLR are needed.

Good to Excellent Functional Short-Term Outcome and Low Revision Rates Following Primary Anterior Cruciate Ligament Repair Using Suture Augmentation

The aim of this study was to evaluate the functional outcome of primary anterior cruciate ligament (ACL) repair using suture augmentation (SA) in 93 consecutive patients (67 female) with a minimum follow-up of 12 months. Patients’ outcomes were determined using International Knee Documentation Committee (IKDC) score, Lysholm score (LS) and Tegner score (TS). Knee-laxity was assessed using the KT-1000 arthrometer. Eighty-eight patients (67 female, mean age 42 years ± standard deviation (SD) 13) were available for follow-up after a mean time of 21 months (range 12–39). Three patients (3%) underwent revision surgery and were excluded from functional analysis. The mean IKDC score was 87.4 ± 11, mean LS was 92.6 ± 11, mean pre-traumatic TS was 6 ± 2 and mean postoperative TS was 6 ± 2, with a mean difference (TS_Diff) of 1 ± 1. The interval from injury to surgery had no significant impact on the postoperative IKDC (p = 0.228), LS (p = 0.377) and TS_Diff (p = 0.572). Patients’ age (>40 years), BMI (>30) and coexisting ligament or meniscal injuries did not seem to influence postoperative functional results. Primary ACL repair using SA provides good to excellent functional outcomes with a low probability of revision surgery at a minimum of 12 months.

Incidence and risk factors of joint stiffness after Anterior Cruciate Ligament reconstruction

Background

Joint stiffness is a common complication after anterior cruciate ligament (ACL) reconstruction, which seriously affects the efficacy of the operation and patient satisfaction. After ACL reconstruction, the identification of joint stiffness’ risk factors can help its prevention. This meta-analysis was conducted to evaluate joint stiffness’ risk factors and incidence after ACL reconstruction and provide guidance on its prevention.

Methods

PubMed, Embase, and Cochrane Library were searched to obtain relevant studies. The odds ratios (ORs) with 95% confidence intervals (CIs) for all potential risk factors were analyzed using fixed or random-effects meta-analysis in RevMan 5.2.

Results

In total, there were 37 studies and 113,740 patients that were included in this study. After ACL reconstruction, joint stiffness’ incidence negatively correlated with the studies publication time (R = −0.62, P = 0.0094). After ACL reconstruction, the joint stiffness overall pooled incidence was 3% (95% CI, 3-4%). Gender (OR, 0.51; 95% CI, 0.38-0.68; P < 0.00001) was identified as a risk factor. Potential risk factors, such as trauma to surgery time interval, graft type, and concomitant surgery with meniscus injury, have no significant correlation with joint stiffness after ACL reconstruction.

Conclusion

This study indicated that joint stiffness’ incidence after ACL reconstruction is 3% and that gender is a risk factor for joint stiffness after ACL reconstruction.

Anterior cruciate ligament reconstruction with remnant preservation: current concepts

Anterior cruciate ligament (ACL) tears are a common knee injury, and anatomic ACL reconstruction (ACLR) is now the standard of care to restore knee stability. Nevertheless, re-tear rates exceeding 5% are commonly reported, with an even higher percentage of patients unable to achieve preinjury knee function. As the torn ACL remnant contains elements (eg, cells, blood vessels and mechanoreceptors) essential to ACL function, it has been hypothesised that ACLR with remnant preservation may improve graft remodelling, in turn more quickly and completely restoring ACL structure and function. In this Current Concepts review, we summarise the present understanding of ACLR with remnant preservation, which includes selective bundle reconstruction of partial (one-bundle) ACL tears and single- and double-bundle ACLR with minimal to partial debridement of the torn ACL stump. Reported benefits of remnant preservation include accelerated graft revascularisation and remodelling, improved proprioception, decreased bone tunnel enlargement, individualised anatomic bone tunnel placement, improved objective knee stability and early mechanical support (with selective bundle reconstruction) to healing tissues. However, clinical studies of ACLR with remnant preservation are heterogeneous in the description of remnant characteristics and surgical technique. Presently, there is insufficient evidence to support the superiority of ACLR with remnant preservation over the standard technique. Future studies should better describe the ACL tear pattern, remnant volume, remnant quality and surgical technique. Progress made in understanding and applying remnant preservation may inform, and be reciprocally guided by, ongoing research on ACL repair. The goal of research on ACLR with remnant preservation is not only to achieve anatomic structural restoration of the ACL but also to facilitate biologic healing and regeneration to ensure a more robust and functional graft.

Repair With Dynamic Intraligamentary Stabilization Versus Primary Reconstruction of Acute Anterior Cruciate Ligament Tears: 2-Year Results From a Prospective Randomized Study

BACKGROUND

Anterior cruciate ligament (ACL) repair has once again become a focus of research because of the development of new techniques.

PURPOSE/HYPOTHESIS

The purpose was to compare the functional results and recurrent instability rates in patients undergoing ACL repair with dynamic intraligamentary stabilization (DIS) versus primary ACL reconstruction (ACLR) for acute isolated ACL tears. The hypothesis was that functional results and knee joint stability after ACL repair with DIS would be comparable with that after ACLR.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 1.

METHODS

A total of 85 patients with acute ACL tears were randomized to undergo either ACL repair with DIS or primary ACLR. The preinjury activity level and function were recorded. Follow-up examinations were performed at 6 weeks and 6, 12, and 24 months postoperatively. Anterior tibial translation (ATT) was evaluated using Rolimeter testing. The Tegner activity scale, International Knee Documentation Committee (IKDC) subjective form, and Lysholm knee scoring scale scores were obtained. Clinical failure was defined as ΔATT >3 mm in combination with subjective instability. Recurrent instability and other complications were recorded.

RESULTS

There were 83 patients (97.6%) who were successfully followed until 2 years. ATT was significantly increased in the DIS group compared with the ACLR group (ΔATT, 1.9 vs 0.9 mm, respectively; P = .0086). A total of 7 patients (16.3%) in the DIS group had clinical failure and underwent single-stage revision. In the ACLR group, 5 patients (12.5%) had failure of the reconstruction procedure; 4 of these patients required 2-stage revision. The difference in the failure rate was not significant (P = .432). There were 4 patients (3 in the DIS group and 1 in the ACLR group) who showed increased laxity (ΔATT >3 mm) without subjective instability and did not require revision. Recurrent instability was associated with young age (<25 years) and high Tegner scores (>6) in both groups. No significant differences between ACL repair with DIS and ACLR were found for the Tegner, IKDC, and Lysholm scores at any time.

CONCLUSION

Whereas ATT measured by Rolimeter testing was significantly increased after ACL repair with DIS, clinical failure was similar to that after ACLR. In addition, functional results after ACL repair with DIS for acute tears were comparable with those after ACLR. The current study supports the use of ACL repair with DIS as an option to treat acute ACL tears.

REGISTRATION

DRKS00015466 (German Clinical Trials Register).

Clinical Outcomes of Arthroscopic Primary Anterior Cruciate Ligament Repair: A Systematic Review from the Scientific Anterior Cruciate Ligament Network International Study Group

PURPOSE

To perform a systematic review of contemporary studies reporting clinical outcomes of primary anterior cruciate ligament (ACL) repair to determine whether these studies demonstrate any significant benefit of ACL repair and whether there is evidence of a deterioration of mid-term outcomes as seen in historical data.

METHODS

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A PubMed search using the keywords "repair" AND "Anterior Cruciate Ligament" was performed (limits: English language, publication date between January 1, 2014, and January 13, 2019). All identified studies reporting clinical outcomes of arthroscopic ACL repair were included. Critical appraisal was conducted using the Cochrane Risk of Bias Tool for Randomized Clinical Trials and the Methodological Index for Non-Randomized Studies. Basic parameters of each study including population characteristics, repair technique, physical examination findings, and clinical outcome scores were recorded and evaluated.

RESULTS

Nineteen eligible studies were identified (including 5 comparative studies). None of the comparative studies showed any significant difference between repair and reconstruction groups with respect to International Knee Documentation Committee (IKDC), Lysholm, Tegner, side-to-side laxity difference, Lachman, pivot shift tests, or graft rupture rates. Four non-comparative studies reported outcomes at medium- to long-term follow up (range of mean follow up 43.3-79 months) with a mean Lysholm score between 85.3 and 100, mean IKDC subjective score between 87.3 and 100, and mean Tegner activity score between 5 and 7.

CONCLUSIONS

Comparative studies identified no significant differences between ACL repair and reconstruction with respect to Lysholm, IKDC, side-to-side laxity difference, pivot shift grade, or graft rupture rates. However, these studies had major limitations including small numbers and short durations of follow up. Case series demonstrated that excellent outcomes can be achieved at medium- to long-term follow up with the SAR technique.

LEVEL OF EVIDENCE

IV; Systematic review of Level II to IV investigations.

Seventy percent long-term survival of the repaired ACL after dynamic intraligamentary stabilization

PURPOSE

Primary repair of the anterior cruciate ligament (ACL) is regaining popularity. Long-term results are lacking. The purpose of the current study was to determine the survival of the primarily repaired ACL after dynamic intraligamentary stabilization.

METHODS

Between 2011 and 2013, 57 patients with acute proximal ACL ruptures underwent DIS repair within 3 weeks from injury and were available for final follow-up at least 5 years postoperatively. Failure as an end point was defined as conversion to ACL reconstruction, failure to restore stability with persisting laxity side-to-side laxity of > 5 mm or a late-traumatic re-rupture or loss of stability. Kaplan-Meier survival analysis was performed.

RESULTS

Kaplan-Meier survival analysis demonstrated an overall survival of 70.0% (standard error SE 6.6%) at 74 months follow-up. Patients performing competitive sports prior to injury demonstrated an inferior long-term ACL survival of 56.4% (SE 11.6%). Patients performing recreational sport activities demonstrated a survival rate of 79.2% (SE 7.7%). The one factor demonstrating a direct influence on failure after adjustment was a high-pre-injury level of physical (odds ratio 4.0 confidence interval 1.0-15.8, p = 0.04).

CONCLUSION

The minimum 5 years survival rate after primary ACL repair using this technique was 70%. This value dropped to 56% in highly active patients performing competitive sports. Patients not suffering failure of repair demonstrated adequate restoration of knee laxity and high satisfaction. This study not only underlines the potential of ACL repair, but also highlights the danger of the procedure if strict patient selection is not appreciated.

LEVEL OF EVIDENCE

Level IV.

Arthroscopic primary repair of proximal anterior cruciate ligament tears seems safe but higher level of evidence is needed: a systematic review and meta-analysis of recent literature

PURPOSE

To assess the outcomes of the various techniques of primary repair of proximal anterior cruciate ligament (ACL) tears in the recent literature using a systematic review with meta-analysis.

METHODS

PRISMA guidelines were followed. All studies reporting outcomes of arthroscopic primary repair of proximal ACL tears using primary repair, repair with static (suture) augmentation and dynamic augmentation between January 2014 and July 2019 in PubMed, Embase and Cochrane were identified and included. Primary outcomes were failure rates and reoperation rates, and secondary outcomes were patient-reported outcome scores.

RESULTS

A total of 13 studies and 1,101 patients (mean age 31 years, mean follow-up 2.1 years, 60% male) were included. Nearly all studies were retrospective studies without a control group and only one randomized study was identified. Grade of recommendation for primary repair was weak. There were 9 out of 74 failures following primary repair (10%), 6 out of 69 following repair with static augmentation (7%) and 106 out of 958 following dynamic augmentation (11%). Repair with dynamic augmentation had more reoperations (99; 10%), and more hardware removal (255; 29%) compared to the other procedures. All functional outcome scores were > 85% of maximum scores.

CONCLUSIONS

This systematic review with meta-analysis found that the different techniques of primary repair are safe with failure rates of 7-11%, no complications and functional outcome scores of > 85% of maximum scores. There was a high risk of bias and follow-up was short with 2.1 years. Prospective studies comparing the outcomes to ACL reconstruction with sufficient follow-up are needed prior to widespread implementation.

LEVEL OF EVIDENCE

IV.

Anterior Cruciate Ligament Repair Outcomes: An Updated Systematic Review of Recent Literature

PURPOSE

To critically review recent literature on outcomes following primary surgical repair of the anterior cruciate ligament (ACL).

METHODS

In December 2018, a search of the MEDLINE database was conducted for English language articles reporting clinical outcomes of ACL repair from 2003 to 2018. Included studies were evaluated for patient demographics, patient-reported outcome measures, return to sports/work, patient satisfaction, and postoperative complications. Subgroup analysis was conducted for studies that included patients with only type 1/proximal ACL ruptures.

RESULTS

Twenty-eight studies satisfied the inclusion criteria, comprising 2,401 patients (52.3% male, 35.7% female, 12.0% unspecified gender) with mean age ranging from 6.0 to 43.3 years. Most studies were conducted in Europe (82.1%), were level of evidence IV (60.7%), and were designed as case series (57.1%). Fourteen investigations (50.0%) used primary suture repair and 14 (50.0%) used dynamic intraligamentary stabilization. Preoperative ranges for Lysholm, International Knee Documentation Committee Score subjective, and Tegner scores were 28 to 100, 94.1 to 100, and 2 to 9, respectively. Postoperative ranges for the same measures were 80 to 100, 54.3 to 98, and 3.67 to 7, respectively. Time to return to sport/work ranged from 3.1 ± 3.3 to 17.4 ± 1.5 weeks. Frequency of rerupture, revision ACL surgery, and overall reoperations were as high as 23.1%, 33.3%, and 51.5%, respectively. Overall ACL repair survivorship ranged from 60.0% to 100.0%. In subgroup analysis for proximal ruptures treated with repair, the rates of revision ACL reconstruction (ACLR) and total reoperations were as high as 12.9% and 18.2%, respectively.

CONCLUSIONS

Based on our cumulative findings across 2,401 patients from the 28 included studies, it appears that ACLR results in better survivorship and patient-perceived postoperative improvement when compared with ACL repair. At present, ACLR appears to remain the superior treatment strategy in the vast majority of cases.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

Acute Anterior Cruciate Ligament Rupture: Repair or Reconstruction? Two-Year Results of a Randomized Controlled Clinical Trial

BACKGROUND

Contemporary anterior cruciate ligament (ACL) suture repair techniques have been subject to renewed interest in recent years. Although several clinical studies have yielded good short-term results, high-quality evidence is lacking in regard to the effectiveness of this treatment compared with ACL reconstruction.

HYPOTHESIS

Dynamic augmented ACL suture repair is at least as effective as anatomic single-bundle ACL reconstruction for the treatment of acute ACL rupture in terms of patient self-reported outcomes at 2 years postoperatively.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

After stratification and randomization, 48 patients underwent either dynamic augmented ACL suture repair or ACL reconstruction with a single-bundle, all-inside, semitendinosus technique. The International Knee Documentation Committee (IKDC) subjective score at 2 years postoperatively was the primary outcome measure. Patient-reported outcomes (IKDC subjective score, Knee injury and Osteoarthritis Outcome Score, Tegner score, visual analog scale for satisfaction), clinical outcomes (IKDC physical examination score, leg symmetry index for the quadriceps, hamstrings strength, and jump test battery), and radiological outcomes as well as adverse events including reruptures were recorded. Analyses were based on an intention-to-treat principle.

RESULTS

The lower limit for the median IKDC subjective score of the repair group (86.2) fell within the prespecified noninferiority margin, confirming noninferiority of dynamic augmented ACL suture repair compared with ACL reconstruction. No statistical difference was found between groups for median IKDC subjective score (repair, 95.4; reconstruction, 94.3). Overall, 2 reruptures (8.7%) occurred in the dynamic ACL suture repair group and 4 reruptures (19.0%) in the ACL reconstruction group; further, 5 repeat surgeries-other than for revision ACL surgery-took place in 4 patients from the dynamic ACL suture repair group (20.8%) and in 3 patients from the ACL reconstruction group (14.3%).

CONCLUSION

Dynamic augmented ACL suture repair is not inferior to ACL reconstruction in terms of subjective patient-reported outcomes as measured with the IKDC subjective score 2 years postoperatively. However, for reasons other than revision ACL surgery due to rerupture, a higher number of related adverse events leading to repeat surgery were seen in the dynamic augmented ACL suture repair group within 2 years postoperatively.

CLINICAL RELEVANCE

Dynamic augmented ACL suture repair might be a viable treatment option for patients with an acute ACL rupture.

REGISTRATION

NCT02310854 ( ClinicalTrials.gov identifier).

Dynamic intraligamentary stabilization for ACL repair: a systematic review

PURPOSE

It was the aim to assess all published original research dealing with dynamic repair of the anterior cruciate ligament (ACL) and to provide a semi-quantitative analysis of clinical outcome reports.

METHODS

Both OVIS and MEDLINE databases were utilized for allocation of articles. All preclinical and clinical studies related to dynamic intraligamentary stabilization (DIS) were identified. Results were tabulated and semi-quantitative analysis performed.

RESULTS

Twenty-three articles related to DIS were identified. The predominant level of evidence ranged between II and IV, with only one level I study. Reported failure rates ranged between 4% and 13.6%. Most clinical studies only reported revision rates without referring to failure of restoring stability. Highest success was achieved with proximal ACL ruptures. Both the level of physical activity and  patient age have been found to influence the risk of failure.

CONCLUSION

There is sufficient evidence to support that DIS repair may be an effective modality for the treatment of acute proximal tears of the ACL. However, comparative studies are lacking. Upcoming studies should compare the technique to ACL reconstruction with failure as an endpoint. Comparison to rigid methods of proximal fixation is also necessary to justify the need for dynamic fixation. Overall, there is evidence to suggest the potential space for ACL repair in the decision tree for individualized treatment planning. The best outcome will be in the hands of the best patient selectors.

LEVEL OF EVIDENCE

IV.

Arthroscopic primary repair of proximal anterior cruciate ligament tears: outcomes of the first 56 consecutive patients and the role of additional internal bracing

PURPOSE

Recent outcomes of arthroscopic primary repair of proximal anterior cruciate ligament (ACL) tears have been promising in small cohort studies. The purpose of this study was to assess outcomes of arthroscopic ACL repair in a larger cohort and to assess the role of additional augmentation.

METHODS

The first 56 consecutive patients that underwent arthroscopic ACL repair were examined at minimum 2-year follow-up. The latter 27 patients [48.2% (27/56)] received additional internal bracing with ACL repair. All 56 patients were included (100% follow-up). Mean age at surgery was 33.5 ± 11.3 years (59% male) and mean follow-up 3.2 ± 1.7 years. Clinical examination was performed using the objective International Knee Documentation Committee (IKDC) form. Subjective outcomes were obtained using the Lysholm, modified Cincinnati, Single Assessment Numeric Evaluation (SANE), and subjective IKDC scores.

RESULTS

Six repairs (10.7%) failed and four additional patients underwent reoperation (7.1%): two for meniscus tears and two for suture anchor irritation. Objective IKDC scores were A in 38 (73%), B in 8 (15%) and C/D in 6 (12%) patients. Mean Lysholm score was 94 ± 7.6, modified Cincinnati 94 ± 8.9, SANE 90 ± 12.5, pre-injury Tegner 6.7 ± 1.5, current Tegner 6.2 ± 1.5, and subjective IKDC 90 ± 10.9. Failures rates were 7.4% with and 13.8% without internal bracing (P = 0.672). There were no statistically significant or clinically relevant differences in subjective outcomes.

CONCLUSION

Arthroscopic primary repair has resulted in good objective and subjective outcomes at 3.2-year follow-up in a carefully selected population. The role of additional internal bracing is possibly beneficial, but larger groups are needed to assess this.

LEVEL OF EVIDENCE

III.

High complication rate following dynamic intraligamentary stabilization for primary repair of the anterior cruciate ligament

PURPOSE

New strategies for dynamic intraligamentary stabilization (DIS) in the primary repair of anterior cruciate ligament (ACL) ruptures are currently under debate. It has been proposed that these might serve as alternative techniques to conventional ACL reconstruction procedures using tendon autografts. The aims of the present investigation were to evaluate the functional results and critically assess the complication rate following primary ACL repair with DIS and to review existing reports of favourable clinical results with the method in relation to knee joint stability and patient satisfaction.

METHODS

Fifty-nine patients received dynamic intraligamentary stabilization a mean of 14 days after ACL rupture. Fifty-seven patients (96.6%, male:female = 37:20; mean age 27.6 years) were available for follow-up examinations including the Tegner activity level, anteroposterior stability in comparison with the uninjured knee, subjective satisfaction, and range of knee motion. Complications after 3 and 12 months were also analyzed. Associated lesions requiring surgical measures were found in 30 patients.

RESULTS

A statistically significant decrease in Tegner activity levels was detected between the preoperative status (median 7) and the 12-month follow-up (median 5). The overall complication rate was 57.9%, including rerupture or non-healing (n = 10, 17.5%), repeat arthroscopy (n = 13, 22.8%) as a result of meniscus tears (n = 2, 15.4%), cyclops syndrome (n = 4, 30.8%) or restricted range of motion (n = 7, 53.8%), arthrofibrosis (n = 3, 5.3%), and implant interference (n = 7, 12.3%). Anteroposterior KT-1000 stability of 3 mm or below was achieved in 29 (50.9%) patients.

CONCLUSIONS

The DIS procedure does not appear to be appropriate for providing predictable results in a young and active cohort of patients following ACL rupture, as it has an unacceptably high complication rate and leads to residual anteroposterior knee joint laxity of 3 mm or more in 28 (49.1%) of cases.

LEVEL OF EVIDENCE

IV (prospective case series).

Improved results of ACL primary repair in one-part tears with intact synovial coverage

PURPOSE

It was the aim to assess the influence of synovial sheath disruption on early failure of primary anterior cruciate ligament (ACL) repair. It was hypothesized that more-part ACL tears with disruption of the synovial sheath are associated with a higher risk of failure after primary ACL repair.

METHODS

A cohort study was conducted comprising patients with primal ACL tears undergoing primary ACL repair and dynamic intraligamentary stabilization (DIS). The patients were stratified into three groups: A-one-part rupture with intact synovial membrane (n = 50), B-two-part ruptures resultant to separation of the ACL into two main bundles with synovial membrane tearing (n = 52) and C-more parts involving multilacerated ruptures with membrane disruption (n = 22). Failure was defined as a retear or residual laxity (anterior posterior translation > 5 mm compared to healthy knee). Adjustment for potential risk factors was performed using a multivariate logistic-regression model.

RESULTS

The overall failure rate was 17.7% throughout the mean follow-up period of 2.3 ± 0.8 years. The failure rate in patients with one-part ACL tears with an intact synovial membrane was 4% (n = 2) (Group A), which was significantly lower than the failure rates in groups B and C, 26.9% (n = 14) (p = 0.001) and 27.3% (n = 6) (p = 0.003), respectively. Disruption of the synovial sheath in two- or more-part tears was identified as an independent factor influencing treatment failure in primary ACL repair (OR 8.9; 95% CI 2.0-40.0).

CONCLUSION

The integrity of the ACL bundles and synovial sheath is a factor that influences the success of ACL repair. This needs to be considered intra-operatively when deciding about repair.

LEVEL OF EVIDENCE

IV.

Surgeon experience with dynamic intraligamentary stabilization does not influence risk of failure

PURPOSE

Studies on dynamic intraligamentary stabilization (DIS) of acute anterior cruciate ligament (ACL) ruptures reported failure rates similar to those of conventional ACL reconstruction. This study aimed to determine whether surgeon experience with DIS is associated with revision rates or patient-reported outcomes. The hypothesis was that more experienced surgeons achieved better outcomes following DIS due to substantial learning curve.

METHODS

The authors prospectively enrolled 110 consecutive patients that underwent DIS and evaluated them at a minimum of 2 years. The effects of independent variables (surgeon experience, gender, age, adjuvant procedures, tear location, preinjury Tegner score, time from injury to surgery, and follow-up) on four principal outcomes (revision ACL surgery, any re-operation, IKDC and Lysholm score) were analyzed using univariable and multivariable regressions.

RESULTS

From the 110 patients enrolled, 14 patients (13%) were lost to follow-up. Of the remaining 96 patients, 11 underwent revision ACL surgery, leaving 85 patients for clinical assessment at a mean of 2.2 ± 0.4 years (range 2.0-3.8). Arthroscopic reoperations were performed in 26 (27%) patients, including 11 (11%) revision ACL surgeries. Multivariable regressions revealed: (1) no associations between the reoperation rate and the independent variables, (2) better IKDC scores for 'designer surgeons' (b = 10.7; CI 4.9-16.5; p < 0.001), higher preinjury Tegner scores (b = 2.5, CI 0.8-4.2; p = 0.005), and younger patients (b = 0.3, CI 0.0-0.6; p = 0.039), and (3) better Lysholm scores for 'designer surgeons' (b = 7.8, CI 2.8-12.8; p = 0.005) and preinjury Tegner score (b = 1.9, CI 0.5-3.4; p = 0.010).

CONCLUSION

Surgeon experience with DIS was not associated with rates of revision ACL surgery or general re-operations. Future, larger-scaled studies are needed to confirm these findings. Patients operated by 'designer surgeons' had slightly better IKDC and Lysholm scores, which could be due to better patient selection and/or positively biased attitudes of both surgeons and patients.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Dynamic augmentation restores anterior tibial translation in ACL suture repair: a biomechanical comparison of non-, static and dynamic augmentation techniques

PURPOSE

There is a lack of objective evidence investigating how previous non-augmented ACL suture repair techniques and contemporary augmentation techniques in ACL suture repair restrain anterior tibial translation (ATT) across the arc of flexion, and after cyclic loading of the knee. The purpose of this work was to test the null hypotheses that there would be no statistically significant difference in ATT after non-, static- and dynamic-augmented ACL suture repair, and they will not restore ATT to normal values across the arc of flexion of the knee after cyclic loading.

METHODS

Eleven human cadaveric knees were mounted in a test rig, and knee kinematics from 0° to 90° of flexion were recorded by use of an optical tracking system. Measurements were recorded without load and with 89-N tibial anterior force. The knees were tested in the following states: ACL-intact, ACL-deficient, non-augmented suture repair, static tape augmentation and dynamic augmentation after 10 and 300 loading cycles.

RESULTS

Only static tape augmentation and dynamic augmentation restored ATT to values similar to the ACL-intact state directly postoperation, and maintained this after cyclic loading. However, contrary to dynamic augmentation, the ATT after static tape augmentation failed to remain statistically less than for the ACL-deficient state after cyclic loading. Moreover, after cyclic loading, ATT was significantly less with dynamic augmentation when compared to static tape augmentation.

CONCLUSION

In contrast to non-augmented ACL suture repair and static tape augmentation, only dynamic augmentation resulted in restoration of ATT values similar to the ACL-intact knee and decreased ATT values when compared to the ACL-deficient knee immediately post-operation and also after cyclic loading, across the arc of flexion, thus allowing the null hypotheses to be rejected. This may assist healing of the ruptured ACL. Therefore, this study would support further clinical evaluation of dynamic augmentation of ACL repair.

SPECT/CT in the Postoperative Painful Knee

This review summarizes the role of SPECT/CT in patients with a painful postoperative knee and describes typical diagnostic criteria in these patients. Pain after knee surgery is common and is influenced by the underlying pathology, the type of surgery, and the patient. Knee joint-preserving surgery includes osteotomy, ligament reconstruction, meniscus surgery, and cartilage repair procedures, often used in combination. Knee arthroplasty procedures consist of unicondylar, patellofemoral, and primary or revision total knee prosthesis. In patients with pain after knee joint-preserving surgery, MRI remains the reference standard. After ligament reconstruction, CT can evaluate postoperative tunnel positioning, and bone SPECT/CT can contribute by assessing overloading or biodegradation problems. After meniscal or cartilage surgery, SPECT/CT can be particularly helpful to identify compartment overloading or nonhealing chondral or osteochondral lesions as cause of pain. SPECT/CT arthrography can assess cartilage damage at an early stage due to altered biomechanical forces. After corrective osteotomy of the knee, SPECT/CT can reveal complications such as overloading, nonunion, or patellofemoral problems. After arthroplasty, conventional radiographs lack both sensitivity to detect aseptic loosening and specificity in differentiating aseptic from infectious loosening. Secondly, hardware-induced artifacts still hamper CT and MRI, despite improving and increasingly available metal artifact reduction techniques. Bone scintigraphy is a proven useful adjunct to conventional radiography and MRI to reveal the pain generator and is less hampered by artifacts from metallic implants compared with CT and MRI. Nevertheless, the optimal imaging strategy in evaluating complications after knee arthroplasty is still a matter of debate. Although the evidence of the use of BS SPECT/CT is still limited, it is growing steadily. In particular, recent data on specific uptake patterns in tibial and femoral zones after total knee arthroplasty and the impact of integrating biomechanics into the assessment of SPECT/CT appear promising, but more research is needed.

Anterior cruciate ligament repair - past, present and future

Background

This article provides a detailed narrative review on the history and current concepts surrounding ligamentous repair techniques in athletic patients. In particular, we will focus on the anterior cruciate ligament (ACL) as a case study in ligament injury and ligamentous repair techniques. PubMed (MEDLINE), EMBASE and Cochrane Library databases for papers relating to primary anterior cruciate ligament reconstruction were searched by all participating authors. All relevant historical papers were included for analysis. Additional searches of the same databases were made for papers relating to biological enhancement of ligament healing.

Current standard

The poor capacity of the ACL to heal is one of the main reasons why the current gold standard surgical treatment for an ACL injury in an athletic patient is ACL reconstruction with autograft from either the hamstrings or patella tendon. It is hypothesised that by preserving and repairing native tissues and negating the need for autograft that primary ACL repair may represent a key step change in the treatment of ACL injuries.

History of primary ACL repair

The history of primary ACL repair will be discussed and the circumstances that led to the near-abandonment of primary ACL repair techniques will be reviewed.

New primary repair techniques

There has been a recent resurgence in interest with regards to primary ACL repair. Improvements in imaging now allow for identification of tear location, with femoral-sided injuries, being more suitable for repair. We will discuss in details strategies for improving the mechanical and biological environment in order to allow primary healing to occur.

In particular, we will explain mechanical supplementation such as Internal Brace Ligament Augmentation and Dynamic Intraligamentary Stabilisation techniques. These are novel techniques that aim to protect the primary repair by providing a stabilising construct that connects the femur and the tibia, thus bridging the repair.

Bio enhanced repair

In addition, biological supplementation is being investigated as an adjunct and we will review the current literature with regards to bio-enhancement in the form platelet rich plasma, bio-scaffolds and stem cells. On the basis of current evidence, there appears to be a role for bio-enhancement, however, this is not yet translated into clinical practice.

Conclusions

Several promising avenues of further research now exist in the form of mechanical and biological augmentation techniques. Further work is clearly needed but there is renewed interest and focus for primary ACL repair that may yet prove the new frontier in ligament repair.