Recovery of ACL function after dynamic intraligamentary stabilization is resultant to restoration of ACL integrity and scar tissue formation

Anterior cruciate ligament primary repair revision rates are increased in skeletally mature patients under the age of 21 compared to reconstruction, while adults (>21 years) show no significant difference: A systematic review and meta-analysis

PURPOSE

To evaluate the impact of age as a risk factor on the revision rates of anterior cruciate ligament (ACL) primary repair (ACLPR), dynamic intraligamentary stabilization (DIS) and bridge-enhanced ACL restoration (BEAR) compared to ACL reconstruction (ACLR).

METHODS

A systematic literature search was performed for comparative studies comparing outcomes for ACLPR, DIS or BEAR to ACLR. A random-effects meta-analysis was performed to assess nondifferentiated and age-differentiated (skeletally mature patients ≤21 and >21 years) ACL revision and reoperation risk, as well as results for subjective outcomes. Methodological study quality was assessed using the Risk of Bias Tool 2.0c and Methodological Index for Nonrandomized Studies tools.

RESULTS

A total of 12 studies (n = 1277) were included. ACLR demonstrated a lower nonage-stratified revision risk at 2 years versus ACLPR, DIS and BEAR, but a similar revision risk at 5 years when compared to DIS. However, an age-stratified analysis demonstrated a significantly increased ACLPR revision risk as compared to ACLR in skeletally mature patients ≤21 years of age (risk ratios [RR], 6.33; 95% confidence interval [CI], 1.18-33.87, p = 0.03), while adults (>21 years) showed no significant difference between groups (RR, 1.48; 95% CI, 0.25-8.91, n.s.). Furthermore, DIS reoperation rates were significantly higher than respective ACLR rates (RR, 2.22; 95% CI, 1.35-3.65, p = 0.002), whereas BEAR (RR, 1.07; 95% CI, 0.41-2.75, n.s.) and ACLPR (RR, 0.81; 95% CI, 0.21-3.09, n.s.) showed no differences. IKDC scores were equivalent for all techniques. However, ACLPR exhibited significantly better FJS (mean difference, 11.93; 95% CI, 6.36-17.51, p < 0.0001) and Knee injury and Osteoarthritis Outcome Score Symptoms (mean difference, 3.01; 95% CI, 0.42-5.60, p = 0.02), along with a lower Tegner activity reduction.

CONCLUSIONS

ACLPR in skeletally mature patients ≤21 years of age is associated with up to a six-fold risk increase for ACL revision surgery compared to ACLR; however, adults (>21 years) present no significant difference. Based on the current data, age emerges as a crucial risk factor and should be considered when deciding on the appropriate treatment option in proximal ACL tears.

LEVEL OF EVIDENCE

Level III.

Rehabilitation Following ACL Repair with Internal Brace Ligament Augmentation in Female Gymnast: A Resident's Case Report

Introduction

Anterior Cruciate Ligament (ACL) injuries continue to be a major source of morbidity in gymnastics. The gold standard is to perform an ACL Reconstruction (ACLR). However, injuries to the proximal femoral attachment of the ACL have demonstrated an ability to regenerate. An alternative surgical intervention to the ACLR in this ACL tear subgroup is an ACL repair. The purpose of this case report is to provide a rehabilitation progression for a female gymnast after an ACL repair with Internal Brace Ligament Augmentation (IBLA).

Case Description

The subject was a 16-year-old female who presented with a Sherman Type 1 proximal avulsion of her ACL. She underwent an ACL repair with IBLA. Physical therapy interventions followed a sequential and multi-phased approach based on time for tissue physiologic healing and individual progression. Patient reported outcomes including the International Knee Documentation Committee (IKDC), the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) and the Optimal Screening for Prediction of Referral and Outcome Yellow Flag (OSPRO-YF) were assessed in conjunction with isokinetic strength and hop performance testing to determine return to sport readiness.

Outcomes

The subject completed 42 sessions over the course of 26 weeks in addition to a home exercise program. At return to sport, clinically meaningful improvement was observed in patient reported outcomes including the IKDC, ACL-RSI, and OSPRO-YF. Additionally, strength and hop performance surpassed established thresholds of clinical significance. The subject returned to sport at six months post-operatively.

Conclusion

The subject in this case report returned to full participation in gymnastics six months after an ACL repair with internal bracing following a sequential and multi-phased rehabilitation. The primary ACL repair with IBLA appeared beneficial to this patient and could benefit from additional study in other athletes and athletic populations.

Level of Evidence

Level 5.

Proprioception After Primary Repair of the Anterior Cruciate Ligament

BACKGROUND

Primary repair of the anterior cruciate ligament (ACL) has some potential advantages over the reconstruction technique, which include but are not limited to better knee sensation due to preservation of the natural ACL tissue in patients compared with tendon graft. Proprioception is impaired after ACL injuries and the sense of the joint position is lost.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare arthroscopic ACL primary repair and ACL reconstruction techniques clinically and functionally and analyze the differences in proprioception. It was hypothesized that primary repair would restore knee joint proprioception more successfully because the original tissue of the ACL is preserved.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 63 patients (34 underwent reconstruction and 29 underwent primary repair between 2017 and 2020) and 33 healthy controls, as well as the healthy knees of the operated groups, were evaluated between 24 and 48 months (mean, 29 months) postoperatively. Patients with proximal femoral avulsion tears and stump quality suitable for repair underwent primary repair, and those with tears outside these criteria underwent reconstruction using hamstring tendon autograft. Proprioception was evaluated using the active joint position sensation method during weightbearing, with a digital inclinometer used to measure differences between the target and achieved flexion angles of 15°, 30°, and 60°.

RESULTS

At 15° of knee flexion, the deviation angles for the healthy knee of the reconstruction and primary repair groups were significantly smaller than those of the control group (P < .001), but there was no statistically significant difference between the groups in terms of deviation angle at 30° and 60° of flexion. The deviation angle of the operated knees was statistically significantly larger in the reconstruction group than in the primary repair group at all angles. The deviation angles at 15°, 30°, and 60° were 2.83°, 2.66°, and 2.66° in the reconstruction group and 1.00°, 1.00°, and 1.33° in the primary repair group, respectively (P < .001). There was no statistically significant difference between the reconstruction and primary repair groups in terms of clinical scores.

CONCLUSION

Primary ACL repair can preserve proprioception in a well-selected patient group. In short-term follow-up, primary repair of the ACL in patients with proximal femoral avulsion tears and stump quality suitable for repair appears to be proprioceptively protective. Future studies are needed to clarify the long-term consequences of primary repair on proprioception in a larger population.

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.

Early outcomes of primary repair versus reconstruction for acute anterior cruciate ligament injury: A systematic review and meta-analysis

BACKGROUND

Contemporary techniques for repair of acute anterior cruciate ligament (ACL) rupture have been receiving renewed interest recently because of reports of good outcomes.

METHODS

A literature search of PUBMED, MEDLINE, EMBASE, and the Cochrane Library was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Only RCTs published in English and comparing clinical outcomes of ACL repair versus reconstruction were included. Outcomes were evaluated using the International Knee Documentation Committee subjective score, Lysholm score, Tegner activity scale, visual analog scale pain score, anterior laxity, Lachman test, hop tests, knee injury and osteoarthritis outcome score, extension deficit, revision rate, and re-rupture rate. Statistical analysis was performed with Review Manager 5.4 and Stata 14.0. Two-tailed P < .05 was considered statistically significant.

RESULTS

Four RCTs (with a total of 293 patients) that met the eligibility criteria were included in this review. Over short-term follow-up, none of the studies found significant differences between the repair groups and reconstruction groups with respect to International Knee Documentation Committee, Lysholm, Tegner, visual analog scale, anterior laxity, Lachman test, re-rupture rate, extension deficit, and performance of 3 hop tests (P > .05). In both groups, the hop tests scores were >90%.

CONCLUSION

ACL repair and ACL reconstruction appear to provide comparable short-term outcomes. The low revision rate after primary repair is encouraging. For patients with ACL injury, current repair techniques such as dynamic intraligamentary stabilization and bridge-enhanced ACL repair may be an effective alternative to reconstruction.

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.

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.

The Comparison of Clinical Result between Primary Repair of the Anterior Cruciate Ligament with Additional Internal Bracing and Anatomic Single Bundle Reconstruction-A Retrospective Study

BACKGROUND

The current standard of treatment of anterior cruciate ligament (ACL) is reconstruction (ACLR). This technique has some disadvantages: poor proprioception, donor site morbidity and the inability to restore joint kinematics. ACL repair could be an alternative treatment. The purpose of the study was to compare the stability and the function after ACL primary repair versus single-bundle ACLR.

METHODS

In a retrospective study, 12 patients underwent primary ACL repair with internal bracing, 15 patients underwent standard ACLR. Follow-up examinations were evaluated at up to 2 years postoperatively. One patient in the ACL repair group was lost to follow-up due to re-rupture. The absolute value of anterior tibial translation (ATT) and the side-to-side difference in the same patient (ΔATT) were evaluated using the GNRB arthrometer. The Lysholm knee scoring was obtained. Re-ruptures and other complications were recorded.

RESULTS

Anterior tibial translation (ATT) was significantly decreased in the ACL repair group compared with the ACLR group (5.31 mm vs. 7.18 mm, respectively; p = 0.0137). Arthrometric measurements demonstrated a mean side-to-side difference (ΔATT) 1.87 (range 0.2 to 4.9) mm significantly decreased compared to ACLR 3.36 (range 1.2-5.6 mm; p = 0.0107). The mean Lysholm score was 85.3 points in the ACL repair group and 89.9 in ACLR group. No significant differences between ACL repair and ACLR were found for the Lysholm score. There was no association between AP laxity and clinical outcomes. There were two complications in the internal bracing group: one patient had re-rupture and was treated by ACLR, another had limited extension and had arthroscopic debridement.

CONCLUSIONS

Anterior tibial translation was significantly decreased after ACL repair. Additionally, the functional results after ACL repair with internal bracing were comparable with those after ACLR. It should be noted that the two complications occurred. The current study supports further development of ACL repair techniques.

Rehabilitation Principles to Consider for Anterior Cruciate Ligament Repair

CONTEXT

Injury to the anterior cruciate ligament (ACL) is among the most common orthopaedic injuries, and reconstruction of a ruptured ACL is a common orthopaedic procedure. In general, surgical intervention is necessary to restore stability to the injured knee, and to prevent meniscal damage. Along with surgery, intense postoperative physical therapy is needed to restore function to the injured extremity. ACL reconstruction (ACLR) has been the standard of care in recent decades, and advances in surgical technology have reintroduced the prospect of augmented primary repair of the native ACL via a variety of methods.

EVIDENCE ACQUISITION

A search of PubMed database of articles and reviews available in English was performed through 2020. The search terms ACLR, anterior cruciate ligament repair, bridge enhanced acl repair, suture anchor repair, dynamic intraligamentary stabilization, internal bracing, suture ligament augmentation, and internal brace ligament augmentation were used.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

No exact consensus exists on effective rehabilitation protocols after ACL repair techniques, as the variation in published protocols seem even greater than the variation in those for ACLR. For some techniques such as internal bracing and dynamic interligamentary stabilization, it is likely permissible for the patients to progress to full weightbearing and discontinue bracing sooner. However, caution should be applied with regard to earlier return to sport than after ACLR as to minimize risk for retear.

CONCLUSION

More research is needed to address how physical therapies must adapt to these innovative repair techniques. Until that is accomplished, we recommend that physical therapists understand the differences among the various ACL surgery techniques discussed here and work with the surgeons to develop a rehabilitation protocol for their mutual patients.

STRENGTH OF RECOMMENDATION TAXONOMY (SORT)

C.

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.

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.

[Histological diagnostics in joint pathology due to increasing regenerative therapeutic strategies - special consideration for cartilage damage]

Orthopedic and trauma surgery are currently confronted with significant changes in their interventional and therapeutic strategies, especially in knee surgery. Minimally invasive and reconstructive techniques lead not only to modifications of the repertoire of interventional methods but also of the indications and questions for histopathological diagnostics. The classical problems in knee surgery remain important issues, which are traumatic, degenerative, and infectious lesions. In addition, questions regarding regeneration and integration of cell-material constructs will become more and more important in the future. Furthermore, questions regarding the regenerative potential of an implantation site for such constructs and the morphological quality of harvested tissue for the in vitro cell expansion of autologous cells are becoming increasingly important. The autologous chondrocyte transplantation is a good example of the relevance of the histopathological re-evaluation of the regenerated tissue for a better understanding of the pathophysiology of reconstructive therapies. It becomes clear that for specific aims based on reconstructive therapies, new scoring systems should be established for the histopathological routine diagnostic service. Furthermore, there is need for the definition of further histopathological criteria, which will help to optimize the differential application of reconstructive strategies via tissue engineering. The present report gives a short overview of the modifying requirements on the histopathological diagnostics in specimens from knee-surgery but does not claim to be exhaustive.

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.

Return to Sports after Anterior Cruciate Ligament Injury: a Matched-Pair Analysis of Repair with Internal Brace and Reconstruction Using Hamstring or Quadriceps Tendons

PURPOSE

 The purpose of this study was to evaluate sports activity before anterior cruciate ligament (ACL) injury and after surgical treatment of ACL rupture comparing ACL repair with an Internal Brace to ACL reconstruction using either a hamstring (HT) or quadriceps tendon (QT) autograft.

METHODS

 Between 12/2015 and 10/2016, we recruited 69 patients with a mean age of 33.4 years for a matched-pair analysis. Twenty-four patients who underwent Internal Brace reconstruction were matched according to age (± 5 years), gender, Tegner activity scale (± 1), BMI (± 1) and concomitant injuries with 25 patients who had undergone HT reconstruction and 20 patients who had undergone QT reconstruction. The minimum follow-up was 12 months.

RESULTS

 Overall, the return-to-sports rate was 91.3 %. There were no significant differences (p ≥ 0.05) in the number of sports disciplines and the time before return to sports within or among the groups. Overall and within the groups, the level of sports participation did not change significantly (p ≥ 0.05) postoperatively. The patients' sense of well-being was excellent after either ACL repair with an Internal Brace or ACL reconstruction with autologous HT or QT.

CONCLUSION

 At short-term follow-up, ACL repair using an Internal Brace enables sports activity and provides a sense of well-being similar to that of classic ACL reconstruction using hamstring or quadriceps tendon autografts in a selected patient population.

LEVEL OF EVIDENCE

Level III Retrospective comparative study.

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.

[Dynamic intraligamentary stabilization of acute anterior femoral cruciate ligament rupture : Preliminary and intermediate clinical results]

BACKGROUND

The results of anterior cruciate ligament (ACL) reconstruction demonstrate excellent short and mid-term results; however, long-term follow-up results are compromized by high rates of osteoarthritis. Dynamic intraligamentary stabilization (DIS) focuses on preserving the cruciate ligament. The short and mid-term results of the dynamic ligamentary cruciate ligament suture from a nondevelopmental hospital are presented.

MATERIAL AND METHODS

A total of 73 consecutive patients with an acute rupture of the ACL were included in this prospective study. Patients were surgically treated between July 2014 and October 2017 with DIS within 21 days after ACL rupture. All patients were reviewed before the operation, 60 patients reached a 3‑month follow-up , 51 patients reached a 6‑month follow-up and 38 patients a 12-month follow-up. The perioperative and postoperative complication spectrum was recorded.

RESULTS

The positive results of the developmental clinics were confirmed. The Tegner, Lysholm and International knee documentation Committee (IKDC) scores showed very good results 12 months after surgery. The intraoperative and postoperative complication rates were low at 1.4% and 6.8%, respectively. Postoperative restrictions on movement required re-arthroscopy in 3 patients, 66% of the patients had concomitant damage to the knee joint, which could be treated simultaneously.

CONCLUSION

The dynamic intraligamentary cruciate liament suture (Ligamys) is a successful additional option in the sugical treatment of acute femoral ACL rupture. A high proportion of collateral damage and injuries of the knee joint can be detected and simultaneously treated.

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.

Short-Term Outcome of Multi-Ligament Knee Injury among Sudanese Patients

BACKGROUND:

Multi-ligament knee injury is the state of having two or more of the major knee ligaments, namely: the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), the lateral collateral ligament (LCL), the posteromedial corner (PMC), and the posterolateral corner (PLC). The knee is a hinge joint; this dictates two direction movements on the y-axis plane. The knee joints carry the weight load of the body uniquely. The role of the knee ligaments is not conserved only to maintain knee in a rigid position while standing, but also orchestrates the biomechanics of knee motion in harmony. Multi-ligament knee injury is very rare (incidence < 10:10,000 of trauma cases). Patients with multiple ligaments injuries of the knee become disabled for a long period. This disability rises from the pain and stiffness of the knee joint. A disability that might be associated with increased frequencies of sick leave from work, or much more dire consequences, such as quitting a job or being relieved of duty.

AIM:

To assess the functional outcome of the knee of patients with a multi-ligament knee injury after treatment using a standard scoring system and to determine the recovery rates of each treatment option to a multi-ligament knee injury.

METHODS:

it is a cross-sectional study conducted from January 2018 to January 2019. All patients with multi-ligament knee injuries that were diagnosed by MRI, and underwent reconstruction surgeries or on the waiting list, at Ribat University Hospital and Alyaa Specialized Hospital, Alkuwiti specialised hospital, and Haj Alsafi Hospital for the past 2 years were included. Lyshlome knee scoring scale was used to assess the functional outcome of each patient.

RESULTS:

24 patients were enrolled in this study (16 had reconstruction surgery, 8 did not). 3 had excellent outcome (LKSS = 95 – 100), 8 of them had good score (LKSS = 84-94), 5 had fair outcome (LKSS = 65-83). All those who did not have reconstruction had a poor score (LKSS < 64).

CONCLUSION:

Reconstruction of multi-ligament knee injury shows a good outcome than it was left alone. Post-operative physiotherapy increases the potential of reconstruction. While our data is limited because of the rare condition, we plan to expand our study area to include a larger sample size. We also recommend extending the post-operative physiotherapy to improve the outcome of a multi-ligament knee injury.

MRI following primary repair of the anterior cruciate ligament

Primary repair of the anterior cruciate ligament (ACL) is being performed increasingly in the treatment of acute proximal ACL ruptures. Advantages of ACL repair over surgical reconstruction with a tendon graft include preservation of the anatomy and proprioceptive function of the native ACL, and therefore, faster rehabilitation. The addition of an internal brace protects the repair during ACL healing and can increase the success rate of the procedure. Given this evolution of ACL surgical treatment, radiologists should be familiar with the new repair techniques and their appearances on postoperative imaging. In this article, we describe two different surgical techniques for primary ACL repair, dynamic intraligamentary stabilisation and internal brace ligament augmentation, and provide an overview of the normal and abnormal appearances after this type of repair at magnetic resonance imaging (MRI) follow-up.

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.

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.

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.