Multiple ACL Revision: Failure Analysis and Clinical Outcomes

Combined tibial deflexion osteotomy and anterior cruciate ligament reconstruction improves knee function and stability: A systematic review

IMPORTANCE

Patients with excessive posterior tibial slope (PTS) may have higher risks of anterior cruciate ligament (ACL) reconstruction (ACL-R) failure, and clinical outcomes after revision of ACL-R procedures are typically poor.

OBJECTIVE

This study aimed to perform a systematic review of the literature summarizing the clinical and radiological outcomes of the surgical treatment of ACL insufficiency in the setting of excessive PTS using a tibial deflexion osteotomy combined with ACL-R.

EVIDENCE REVIEW

A systematic review of the literature was performed using PubMed, Cochrane Library, and OVID Medline databases from 1990 to present. Inclusion criteria were studies of outcomes of isolated tibial deflexion osteotomies performed with primary or revision ACL-R in the English language. Data extracted included study demographic information, type of tibial deflexion osteotomy and concomitant procedures, radiological outcomes, patient-reported outcome scores, and postoperative complications.

FINDINGS

Six studies, with 133 knees were identified. All included studies were retrospective case series, with a weighted mean follow-up of 3.39 years. In 106 of 133 (79.7%) knees, tibial deflexion osteotomy was performed concomitantly with an ACL-R, whereas in 27 of 133 (20.3%) knees, the procedures were staged. 22, 45, and 66 of 133 knees (16.5%, 33.8%, and 49.6%) underwent primary, first revision, and second or greater revision ACL-R, respectively. Three of 133 (2.25%) knees demonstrated recurrent ACL graft failure at the final follow-up. On average, PTS decreased from 15.2° preoperatively to 7.1° postoperatively. The mean International Knee Documentation Committee, Lysholm, and Tegner scores increased from 42.5, 46.4, and 4.2 preoperatively to 71.8, 89.0, and 6.7 postoperatively.

CONCLUSIONS

The results of this review suggest that combined ACL-R and tibial deflexion osteotomy may be effective in decreasing PTS and improving knee function and stability.

STUDY DESIGN

Systematic Review; Level of evidence 4.

Comparison of Improvement in Patient-Reported Knee Function After Revision and Multiple-Revision ACL Reconstruction Compared With Primary ACL Reconstruction

Background

Graft failure after anterior cruciate ligament reconstruction (ACLR) is a debilitating complication often requiring revision surgery. It is widely agreed upon that functional knee outcomes after revision ACLR (r-ACLR) are inferior compared with those after primary reconstruction. However, data are scarce on outcomes after multiple-revision ACLR (mr-ACLR).

Purpose

To compare patient-reported knee function in terms of Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and 1-year postoperatively after primary ACLR, r-ACLR, and mr-ACLR and evaluate the pre- to postoperative improvement in KOOS scores for each procedure.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients from the Swedish National Knee Ligament Registry who underwent their index ACLR between 2005 and 2020 with a minimum age of 15 years at the time of surgery were included in this study. All patients had pre- and postoperative KOOS data. The 1-year postoperative KOOS and the pre- to postoperative changes in KOOS were assessed between patients who underwent primary ACLR and those who underwent subsequent r-ACLR and mr-ACLR.

Results

Of 20,542 included patients, 19,769 (96.2%) underwent primary ACLR, 760 (3.7%) underwent r-ACLR, and 13 (0.06%) underwent mr-ACLR. Patients who underwent r-ACLR had significantly smaller pre- to postoperative changes on all KOOS subscales compared with patients undergoing primary ACLR (P < .0001 for all). Furthermore, patients in the mr-ACLR group had significantly smaller changes in the KOOS-Pain subscale compared with patients in the r-ACLR group (-9 ± 23.3 vs 2.5 ± 18; P = .024).

Conclusion

The study results indicated that while improvement is seen after primary ACLR, r-ACLR, and mr-ACLR, the greatest improvement in functional outcomes is observed after primary ACLR. Patients who underwent at least 1 r-ACLR, specifically mr-ACLR, had lower postoperative outcome scores, indicating that primary ACLR may provide the best chance for recovery after ACL injury.

Outcomes of Slope-Reducing Proximal Tibial Osteotomy Combined With a Third Anterior Cruciate Ligament Reconstruction Procedure With a Focus on Return to Impact Sports

BACKGROUND

An increased posterior tibial slope (PTS) is a proven risk factor for both native anterior cruciate ligament (ACL) and ACL graft insufficiency. Anterior closing wedge high tibial osteotomy (ACW-HTO) for PTS correction is a validated procedure in revision ACL reconstruction (ACLR).

PURPOSE/HYPOTHESIS

The aim of this study was to evaluate the effect of combined ACW-HTO and at least a second revision ACLR procedure on knee stability, function, and sports performance in a large series of patients. The hypothesis was that patients would return to impact sports after ACW-HTO combined with a second or third revision ACLR procedure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 64 patients who underwent a second (or more) revision ACLR procedure and ACW-HTO between June 1, 2015, and June 1, 2019, and had a PTS >12° were included. The mean age was 29.60 ± 6.31 years, and the mean preoperative PTS was 13.79°± 1.50°. The cases were analyzed at a mean follow-up of 2.96 ± 0.83 years (range, 2-5 years). At the last follow-up, the rate of patients returning to impact sports (based on the University of California, Los Angeles [UCLA], activity scale), ACL graft status (per magnetic resonance imaging), International Knee Documentation Committee (IKDC) scores, Lysholm scores, and laxity measurements using a knee arthrometer were recorded.

RESULTS

The total number of patients participating in impact sports and high-impact sports was as follows: 43 and 30, respectively, before the injury; 0 and 0, respectively, preoperatively; and 31 and 12, respectively, postoperatively. At the last follow-up, the UCLA score was ≥8 in 48.44% of the patients, and only 16 patients returned to their preinjury level of activity. At a minimum of 2 years of follow-up, there was clinical improvement in the IKDC score from 37.98 ± 12.48 preoperatively to 69.06 ± 12.30 postoperatively (P < .0001), in the Lysholm score from 51.94 ± 14.03 preoperatively to 74.45 ± 11.44 postoperatively (P < .001), and in the UCLA score. However, this clinical improvement did not equate to preinjury values for all outcome scores (P < .001). The preinjury IKDC and Lysholm scores were 76.98 ± 11.71 and 89.26 ± 8.91, respectively. The mean change in anterior knee laxity using a knee arthrometer at 134 and 250 N was -4.03 ± 0.18 mm and -3.63 ± 0.16, respectively. There were 3 cases of a rerupture with a severe pivot shift on the clinical examination. None of these patients underwent revision per the patient's preference. Increased knee recurvatum was observed in one-third of the patients, but all were asymptomatic.

CONCLUSION

In the setting of chronic ACL-deficient knees, PTS reduction (ACW-HTO) with revision ACLR restored knee stability and improved function with an acceptable rate of specific complications. Increased knee recurvatum was observed in one-third of the patients, but all were asymptomatic. Also, approximately half of the patients were able to return to impact sports.

A fast, easy and reliable method for hamstrings graft size prediction in anterior cruciate ligament reconstruction

PURPOSE

The aim of this study is to describe and validate a simple and reliable method to pre-operatively predict the size of the ACL graft in the double strand technique with autologous semitendinosus-gracilis tendons on the same MRI used for ACL rupture diagnosis.

METHODS

The study included 92 patients, with a median age of 31 years (IQR 26-41 years), 73/92 (79%) of whom were males. All patients that underwent an ACL reconstruction with doubled ST + GT between 2017 and 2022 were counted in the study.

RESULTS

Overall, the median predicted graft diameter from MR imaging was similar to the actual graft diameter with no significant differences (n.s.). Regarding the comparison between predicted and actual graft size, concordance was 78/92 (85%, 95% CI 76-91%), with κ = 0.797 which corresponds to a level of agreement defined as "Strong". Tendon sizes calculated on pre-operative MRI were evaluated both with intra-observer and inter-observer reliability demonstrating a statistically reproducible method. The predicted graft was then compared to the reported one with a statistically significant reliability found.

CONCLUSION

This study can help the surgeons to perform a fast pre-operative planning of an ACL reconstruction for graft selection. If the planned graft with ST and GT is smaller than 8 mm, the clinician can decide to switch to a different type of graft or plan a different graft preparing technique and, therefore, reduce the risk of post-operative ligament re-rupture. The method proposed is reliable and reproducible. The major strength of the planning technique proposed is that it relies on data that are already available for the clinician before surgery, without the need of further analysis.

LEVEL OF EVIDENCE

IV.

Good stability and mid-term subjective outcomes after repeated anterior cruciate ligament (ACL) revision surgery using allografts

PURPOSE

To evaluate the mid-term clinical outcomes of a cohort of patients who underwent multiple ACL revision reconstructions. The hypothesis was that patients with pre-existing meniscal deficiency conditions, malalignment and cartilage degeneration would have obtained lower results.

METHODS

All cases of multiple ACL revisions performed with allograft tissue at one single sport-medicine institution were extracted and patients with a minimum 2 years of follow-up were included. WOMAC, Lhysolm, IKDC, and Tegner activity level before the injury and at last follow-up was collected and laxity evaluated with KT-1000 arthrometer and KiRA triaxial accelerometer.

RESULTS

From a cohort of 241 ACL revisions, 28 patients (12%) with Repeated ACL Revision reconstructions were included. Fourteen cases (50%) were considered "Complex" due to the addition of meniscal allograft transplantation (8) or meniscal scaffold (3) or high tibial osteotomy (3). The remaining 14 cases (50%) were considered as "Isolate". The mean WOMAC score was 84.6 ± 11.4, Lysholm 81.7 ± 12.3, subjective IKDC 77.2 ± 12.1, and median Tegner score 6 (IQR 5-6) at pre-injury and at final follow-up. Statistically significant inferior values of WOMAC (p = 0.008), Lysholm (p = 0.02) and Subjective IKDC (p = 0.0193) were detected between "Complex" and "Isolate" revision groups. Higher average values of anterior translation at KT-1000 at both 125 N (p = 0.03) and manual maximum displacement test (p = 0.03) were reported in "Complex" with respect to "Isolate" revisions. Four patients were considered as failures and occurred in patients with "Complex" revisions, none occurred in the "Isolate" (30% vs 0%; p = 0.04).

CONCLUSION

Good mid-term clinical results can be obtained after repeated ACL revision with allograft in patients who experienced multiple failures; however, those who need additional procedure due to malalignment or post-meniscectomy syndrome reported lower objective and subjective results.

LEVEL OF EVIDENCE

III.

Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure.

METHODS

The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects.

RESULTS

A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts.

CONCLUSION

Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.

Multiple revision anterior cruciate ligament reconstruction: not the best but still good

PURPOSE

Given the paucity of literature on the re-revision of ACL, the current study was undertaken. The purpose of this systematic review was to synthesise and qualitatively assess the currently available evidence in the literature regarding the re-revision of ACL reconstruction (rrACLR).

METHODS

A systematic review was conducted based on the PRISMA guidelines. The following search terms were used in the title, abstract and keywords fields: "ACL" or "anterior cruciate ligament" AND "revision" or "multiple" or "repeat". The outcome data extracted from the studies were the Lysholm score, Subjective IKDC, Marx Score, Tegner, Marx Score, KOOS score, radiological changes and the rate of return to sports. Complications, failures and/or revision surgery were also analysed.

RESULTS

The cohort consisted of 295 patients [191 (64.7%) men and 104 (35.3%) women] with a mean age of 29.9 ± 2.8 years (range 14-58 years) from 10 studies. The mean postoperative follow-up (reported in all studies except one) was 66.9 ± 44.7 months (range 13-230.4 months). Associated injuries were 103 (34.9%) medial meniscus tears, 57 (19.3%) lateral meniscus tears, 14 (4.7%) combined medial plus lateral meniscus tears, 11 (3.7%) meniscal tears (not specified), 252 (85.4%) cartilage lesions, 6 (2.0%) medial collateral ligament injury and 2 (0.7%) lateral collateral ligament injuries. In 47 (15.9%) patients an extra-articular plasty was performed for the anterolateral ligament. In all studies that reported pre- and post-operative IKDC (subjective and objective) and Lysholm score, there was a significant improvement compared to the pre-operative value (p < 0.05). At the final follow-up, laxity measured with KT-1000 was found to be 2.2 ± 0.6 mm. 31 (10.5%) out of 295 patients returned to their pre-injury activity level. A total of 19 (6.4%) re-ruptures were found, while only 4 (1.4%) complications (all minors) were reported, out of which 2 (0.7%) were superficial infections, 1 (0.3%) cyclops lesion and 1 (0.3%) flexion loss.

CONCLUSION

Multiple revisions of anterior cruciate ligament reconstruction allow acceptable clinical results and a good degree of knee stability with a low rate of subsequent new re-ruptures but the possibility of regaining pre-injury sports activity is poor; whenever possible, it is preferred to revise the ligament in one stage. This surgery remains a challenge for orthopaedic surgeons and many doubts persist regarding the ideal grafts, additional extra-articular procedures and techniques to use.

LEVEL OF EVIDENCE

IV.

STUDY REGISTRATION

PROSPERO-CRD42022352164 ( https://www.crd.york.ac.uk/prospero/ ).

Return to Sport After Revision ACL Reconstruction: A Comparative Cohort Study of Outcomes After Single- Versus Multiple-Revision Surgeries

BACKGROUND

The return-to-sport rate at 2 years after multiple-revision anterior cruciate ligament (ACL) reconstructions has not been evaluated.

HYPOTHESIS

It was hypothesized that patients who undergo multiple-revision ACL reconstructions would have a lower return-to-sport rate at 2 years after surgery than those who undergo a single-revision reconstruction. Furthermore, it was hypothesized that the multiple-revision group would have lower functional scores.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A single-center cohort study in patients who underwent revision ACL reconstruction was begun in 2012. This study included 2 groups: Patients who underwent a single revision, and those who underwent multiple revisions. The main evaluation criterion was the return to sport at the 2-year follow-up. The secondary criteria were the International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, and ACL-Return to Sport after Injury (ACL-RSI) functional knee scores at the 1- and 2-year follow-ups.

RESULTS

A total of 322 patients (single-revision group: n = 302; multiple-revision group: n = 20) were included. A significant difference in the percentage of patients who stopped all sports activity was found between the 2 groups at 2 years (single-revision group: 19.4%; multiple-revision group: 50%). The return-to-sport rate at the same or lower level of performance was higher in the single-revision group as well (17% vs 14.3% for return at the same level; 45.6% vs 14.3% for return at a lower level; P = .03). At the 2-year follow-up, the functional scores of the single-revision group were significantly higher those than in the multiple-revision group: IKDC (77.7 ± 13.82 vs 64.79 ± 15.22; P < .001), KOOS (72.66 ± 17.63 vs 52.5 ± 15.64; P < .001), Lysholm (84.05 ± 11.88 vs 72.5 ± 13.49; P < .001), and ACL-RSI (52.34 ± 21.83 vs 46.43 ± 14.8; P = .0036).

CONCLUSION

Only a small percentage of patients returned to the same level of sport after single- revision and multiple-revision ACL reconstruction, yet significantly more in the former. More patients who underwent multiple revisions gave up their sport. Functional scores were higher for single-revision than multiple-revision surgeries.

Could anterior closed-wedge high tibial osteotomy be a viable option in patients with high posterior tibial slope who undergo anterior cruciate ligament reconstruction? A systematic review and meta-analysis

PURPOSE

This study aims to examine the clinical and radiological outcomes of patients who underwent ACL reconstruction (ACLR) combined with anterior closed-wedge high tibial osteotomy (ACW-HTO) for posterior tibial slope (PTS) reduction to investigate the efficacy of this procedure in improving anterior knee stability and preventing graft failure in primary and revision ACLR.

METHODS

A literature search was conducted in six databases (PubMed, Embase, Medline, Web of Science, Cochrane, and Scopus). The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The initial screening identified 1246 studies. Each eligible clinical article was screened according to the Oxford Centre for Evidence-Based Medicine 2011 levels of evidence (LoE), excluding clinical studies of LoE V. Quality assessment of the articles was performed using the ROBINS-I methodological evaluation. This systematic review and meta-analysis was registered on the International Prospective Register of Systematic Reviews (PROSPERO). For the outcomes that were possible to perform a meta-analysis, a p < 0.05 was considered statistically significant.

RESULTS

Five clinical studies were included in the final analysis. A total of 110 patients were examined. Pre- and post-operative clinical and objective tests that assess anteroposterior knee stability, PTS, clinical scores, and data on surgical characteristics, complications, return to sports activity, and graft failure after ACLR were investigated. A meta-analysis was conducted using R software, version 4.1.3 (2022, R Core Team), for Lysholm score and PTS outcomes. A statistically significant improvement for both these clinical and radiological outcomes (p < 0.05) after the ACW-HTO surgical procedure was found.

CONCLUSION

ACLR combined with ACW-HTO restores knee stability and function with satisfactory clinical and radiological outcomes in patients with an anterior cruciate ligament injury associated with a high PTS and seems to have a protective effect from further ruptures on the reconstructed ACL.

LEVEL OF EVIDENCE

Level IV.

Small laboratory animal models of anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) injuries are common knee ligament injuries. While generally successful, ACL reconstruction that uses a tendon graft to stabilize the knee is still associated with a notable percentage of failures and long-term morbidities. Preclinical research that uses small laboratory species (i.e., mice, rats, and rabbits) to model ACL reconstruction are important to evaluate factors that can impact graft incorporation or posttraumatic osteoarthritis after ACL reconstruction. Small animal ACL reconstruction models are also used for proof-of-concept studies for the development of emerging biological strategies aimed at improving ACL reconstruction healing. The objective of this review is to provide an overview on the use of common small animal laboratory species to model ACL reconstruction. The review includes a discussion on comparative knee anatomy, technical considerations including types of tendon grafts employed amongst the small laboratory species (i.e., mice, rats, and rabbits), and common laboratory evaluative methods used to study healing and outcomes after ACL reconstruction in small laboratory animals. The review will also highlight common research questions addressed with small animal models of ACL reconstruction.

Tibial slope correction combined with second revision ACLR grants good clinical outcomes and prevents graft rupture at 7-15-year follow-up

PURPOSE

To update previously published outcomes (at 2-8 years) of second revision anterior cruciate ligament reconstruction (ACLR) combined with tibial deflexion osteotomy (TDO), after an interval of 5 more years (at 7-15 years), and monitor evolution of clinical scores and progression of osteoarthritis.

METHODS

The initial retrospective consecutive series included nine patients that underwent one-stage second revision ACLR with TDO, all of whom were contacted for second follow-up at minimum 7 years. An independent observer collected IKDC-SKF, the Lysholm score, and assessed radiographs for signs of osteoarthritis.

RESULTS

Of the nine original patients, seven were assessed at the clinic, one could only be assessed by telephone, and one was lost to follow-up. At final follow-up of 9.9 ± 3.0 years, the eight patients assessed maintained or improved clinical scores, compared to the previous follow-up at 4.0 ± 2.9 years. The mean Lysholm score improved from 73.8 ± 5.8 (65-82) to 84.5 ± 11.9 (59-95), and IKDC improved from 71.6 ± 6.2 (62-79) to 82.9 ± 12.1 (61-98). Of the three patients that had signs of arthritis at the previous follow-up, the stage of osteoarthritis increased in one (from grade 2 to grade 3), remained unchanged in one, and could not be assessed in one.

CONCLUSION

At 7-15 years following second revision ACLR with TDO, patients maintained or improved clinical scores compared to the previous follow-up at 2-8 years, without retears or reoperations. Although eight of the nine knees had meniscectomies or meniscal sutures, osteoarthritis progressed in only one of the six knees that had signs of arthritis at the previous follow-up. These results confirm that TDO can protect the ACL graft from retear, with minimal progression of osteoarthritis and/or risks of meniscal tears, suggesting that correction of excessive tibial slope should be considered when performing ACLR, whether a revision or primary procedure.

Risk Factors Associated with Cartilage Defects after Anterior Cruciate Ligament Rupture in Military Draftees

This study aimed to evaluate the different clinical results and factors associated with cartilage defects in military draftees who underwent different treatments after anterior cruciate ligament (ACL) rupture. Overall, 105 patients who had sustained ACL rupture were military draftees who underwent a conscription examination for physical status assessment from January 2012 to December 2020. Patients were divided into three groups: conservative treatment after ACL rupture, status post-anterior cruciate ligament reconstruction (ACLR), but graft rupture, and status post-ACLR with graft intact. Inter-group comparisons and statistical analyses were performed for age, body mass index (BMI), thigh circumference difference, side-to-side difference in anterior knee translation by KT-2000, meniscus tear, and cartilage defect. Multivariate logistic regression analysis was used to determine the factors associated with cartilage defects. The multivariable regression model showed that BMI (odds ratio OR: 1.303; 95% CI: 1.016–1.672; p = 0.037), thigh circumference difference (OR: 1.403; 95% CI: 1.003–1.084; p = 0.034), tear of lateral meniscus (LM) and medial meniscus (MM) (OR: 13.773; 95% CI: 1.354–140.09; p = 0.027), and graft rupture group (OR: 5.191; 95% CI: 1.388–19.419; p = 0.014) increased the risk of cartilage defects. There was no correlation between cartilage defects and age, KT-2000 difference, tear of LM or MM, or graft intact group. Progression of osteoarthritis was concerned after ACL rupture, and this study identified several factors of post-ACLR graft rupture, greater thigh circumference difference, BMI, and meniscus tear of both LM and MM affecting cartilage defects, which represent early degenerative osteoarthritis changes of the knee. The results of this study should be customized for rehabilitation and military training, especially in military draftees with ACL injuries.

Bench to Bedside: A Multidisciplinary Approach toward the Unknowns after ACL Injuries to Drive Individual Success

ACL injury and surgery are increasing in prevalence. Several challenges exist that can be obstacles to an individual achieving success after ACL surgery. A knowledge of these risk factors alongside a multidisciplinary collaborative team approach can result in a greater likelihood of achieving individual success after ACL surgery.

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AIM

To analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique.

METHODS

From January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability.

RESULTS

Group B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups.

CONCLUSION

ACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.

Revision Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Graft Combined With Modified Lemaire Technique Versus Hamstring Graft Combined With Anterolateral Ligament Reconstruction: A Clinical Comparative Matched Study With a Mean Follow-up of 5 Years From The SANTI Study Group

BACKGROUND

Additional lateral extra-articular tenodesis (LET) has recently been correlated with improved clinical outcomes and reduced failure rates in revision anterior cruciate ligament (ACL) reconstruction (ACLR). However, no data are available on clinical outcomes and reoperation after revision ACLR using different LET procedures.

PURPOSE

To compare the clinical outcomes of ACL + anterolateral ligament (ALL) reconstruction using hamstring tendon graft (HT-ALL) and a bone-patellar tendon-bone (BPTB) graft + modified Lemaire tenodesis procedure (BPTB-Lemaire) in the setting of revision ACLR and to determine whether ALL reconstruction is associated with an increased rate of adverse outcomes when compared with a modified Lemaire tenodesis procedure.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Descriptive data and clinical outcomes were prospectively collected from patients who underwent revision ACLR with LET between 2009 and 2018 with a minimum follow-up of 2 years. Patients with an HT autograft combined with ALL reconstruction (HT-ALL group) were matched in a 1:1 propensity ratio to patients with a BPTB autograft combined with a modified Lemaire LET procedure (BPTB-Lemaire group). The evaluated parameters included complications and reoperations; knee laxity tests; return to sports; and various scores, including the Lysholm knee score, Tegner activity scale, Anterior Cruciate Ligament Return to Sport After Injury scale, Marx activity rating scale, International Knee Documentation Committee subjective knee evaluation form, and Knee injury and Osteoarthritis Outcome Score.

RESULTS

In total, 36 matched pairs were included in the analysis. The mean follow-up durations for the BPTB-Lemaire and HT-ALL groups were 56 ± 35 and 57 ± 23 months, respectively (P = .91). No significant differences were found in graft rupture rate (HT-ALL, 0%; BPTB-Lemaire, 11.1%; P = .13) or reoperations (HT-ALL, 8.3%; BPTB-Lemaire, 22.2%; P = .23). No specific complications with regard to LET were noted in either group. Additionally, there were no significant differences in knee laxity parameters, return to sports, or clinical scores between the groups at the final follow-up, except for the Tegner activity scale score (HT-ALL, 6.4; BPTB-Lemaire, 7.3; P = .03). HT-ALL was associated with a shorter surgical time (41.4 vs 59.8 minutes; P < .0001).

CONCLUSION

HT-ALL was at least equivalent, in terms of clinical outcomes, to the more commonly performed procedure, BPTB-Lemaire. Performing ALL reconstruction in the setting of revision ACLR is therefore safe and effective.

Trauma and femoral tunnel position are the most common failure modes of anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To improve outcomes of anterior cruciate ligament reconstruction (ACLR), it is important to understand the reasons for failure of this procedure. This systematic review was performed to identify current failure modes of ACLR.

METHODS

A systematic search was performed using PubMed, EMBASE, Cochrane, and annual registries for ACLR failures. Studies were included when failure modes were reported (I) of ≥ 10 patients and (II) at a minimum of two-year follow-up. Modes of failure were also compared between different graft types and in femoral tunnel positions.

RESULTS

This review included 24 cohort studies and 4 registry-based studies (1 level I, 1 level II, 10 level III, and 16 level IV studies). Overall, a total of 3657 failures were identified. The most common single failure mode of ACLR was new trauma (38%), followed by technical errors (22%), combined causes (i.e. multiple failure mechanisms; 19%), and biological failures (i.e. failure due to infection or laxity without traumatic or technical considerations; 8%). Technical causes also played a contributing role in 17% of all failures. Femoral tunnel malposition was the most common cause of technical failure (63%). When specifically looking at the bone-patellar tendon-bone (BPTB) or hamstring (HT) autografts, trauma was the most common failure mode in both, whereas biological failure was more pronounced in the HT group (4% vs. 22%, respectively). Technical errors were more common following transtibial as compared to anteromedial portal techniques (49% vs. 26%).

CONCLUSION

Trauma is the single leading cause of ACLR failure, followed by technical errors, and combined causes. Technical errors seemed to play a major or contributing role in large part of reported failures, with femoral tunnel malposition being the leading cause of failure. Trauma was also the most common failure mode in both BPTB and HT grafts. Technical errors were a more common failure mode following transtibial than anteromedial portal technique.

LEVEL OF EVIDENCE

IV.

Histological analysis of ACL reconstruction failures due to synthetic-ACL (LARS) ruptures

INTRODUCTION

Anterior Cruciate Ligament (ACL) reconstruction is an established surgical procedure. Synthetic ligaments represent an option for ACL reconstruction. Their popularity declined for the raising concerns due to re-ruptures, knee synovitis and early arthritis related to I and II generation artificial ligaments. The introduction of a III generation synthetic ligament (Ligament Advanced Reinforcement System-LARS) permitted renewed interest in the adoption of this kind of graft. Main purpose of our study was to describe the histological findings on samples obtained from a consecutive series of ACL revision surgeries due to LARS ACL reconstruction failures. Secondary aim was to determine the reason for LARS rupture.

METHODS

In a period between 2016 and 2018 eleven patients underwent ACL revision surgery due to LARS ACL reconstruction failure. At the time of the arthroscopic procedure, samples of synovial membrane and remnants of the torn LARS were sent to the Pathological-Anatomy Institute of our Hospital for a histological analysis.

RESULTS

Histological analysis of the synovial tissues confirmed the arthroscopic evidence of synovitis mainly characterized by chronic inflammation with predominance of multinucleated giant cells. The adoption of polarized light microscopy revealed the presence of brightly bi-refractive material (LARS wear particles) in the synovial tissue; at higher magnification wear debris were detected inside the cytoplasma of multi nucleated cells. The histological analysis of the removed LARS revealed a surrounding typical foreign body reaction with poor signs of fibrovascular ingrowth of the synthetic ligament.

CONCLUSIONS

Our findings could not clearly advocate a unique mechanism of LARS-ACL reconstruction failure: biologic issues (poor tissue ingrowth) and mechanical issues (fibers properties and tunnel position) probably concur in a multi factorial manner. ACL reconstruction using artificial ligaments can not be considered a simple surgery. Artificial augments require some expertise and could therefore achieve better results if used by skilled sport surgeons other than trainees or low volume surgeons. The Authors believe that ACL reconstruction with synthetic devices still have restricted indications for selected patients (e.g. elderly patients who require a fast recovery, professional athlete, autologous tendons not available and/or refusing donor tendons). Our study arises additional suspicion on the unresponsiveness of synthetic fibers and claim some concern in the implantation of synthetic devices.