What Is the Mid-term Failure Rate of Revision ACL Reconstruction? A Systematic Review

Lateral Extra-Articular Tenodesis and Anterolateral Procedures

The treatment of rotational instability has been an intriguing challenge since the era of modern anterior cruciate ligament (ACL) surgery. Lateral extra-articular procedures (LEAPs) have emerged as a solution to this problem, particularly in high-risk populations. Several studies have shown significant benefits of combining LEAPs with ACL reconstruction, including reduced graft failure rates, improved knee stability, improved rotational stability, and higher return-to-play rates. These findings have led to an in-depth evaluation of LEAPs as lateral extra-articular tenodesis and anterolateral ligament reconstruction and their potential role in improving outcomes after ACL reconstruction.

Does lateral extra-articular tenodesis affect knee stability in cases with isolated anterior cruciate ligament reconstruction?

Objective

The purpose of this randomised controlled trial was to assess the effect on knee function and stabilising effectiveness of lateral extra-articular tenodesis (LET) in anterior cruciate ligament (ACL) restoration.

Methods

A prospective randomised clinical study that compared the functional outcomes of two groups-one undergoing anatomic single bundle ACL reconstruction (ASB-ACLR) with ilio-tibial band tenodesis (LET) for 20 patients, and the other undergoing ASB-ACLR-was carried out between February 2020 and August 2022.

Results

By combining Lateral Extra-articular Tenodesis (LET) with intra-articular Anterior Cruciate Ligament Reconstruction (ACLR), our study observed a significant reduction in the occurrence of high-grade pivot-shift phenomena. Prior to surgery, both Groups A and B exhibited graded (D) pivot-shift test results. However, post-surgery, the pivot-shift test yielded negative results in 60% of patients in Group A and 90% of patients in Group B. The statistical analysis revealed a notable difference between the two groups, as indicated by a P-value of 0.003. Upon conducting a brief follow-up, we evaluated the Lysholm score, and anterior knee stability of ACLR with LET, finding no statistically significant difference compared to those of single ACLR. The Lachman tests also revealed no significant disparity between the two groups (p = 0.106). Analyzing the Lysholm scores in Group A and Group B, we observed an increase to 90.70% and 91.10%, respectively.

Conclusion

Rotational stability is much improved when lateral extra-articular tenodesis (LET) utilizing the ilio-tibial band as an augmentation is used in ACL restoration. Especially useful for high-grade pivot-shift phenomena is this technique.

Anterior cruciate ligament femoral side retained stump technique reduces enlargement of the femoral bone tunnel after anterior cruciate ligament reconstruction

BACKGROUND

Enlargement of the bone tunnel has become an unavoidable early complication after anterior cruciate ligament (ACL) reconstruction, whether it is a single or double-bundle ACL reconstruction. Preservation of the ACL stump in ACL reconstruction reduces enlargement of the bone tunnel. The purpose of this study was to investigate the question of whether single-bundle ACL reconstruction using the ACL femoral side retained stump technique reduces enlargement of the femoral tunnel.

METHODS

Forty patients who underwent single-bundle reconstruction of the ACL were included in this study. The patients were categorized into a Remnant preservation group (Group R) and the Non-remnant preservation group (Group N). In the Remnant preservation group, a high-flexion femoral side retained stump technique was used intraoperatively for the establishment of the femoral side bone tunnel, and in the Non-remnant preservation group, the conventional femoral positioning method was used (we used a femoral positioning drill for localization and drilling of the femoral bone tunnel), and MRI of the operated knee joints was performed at 6 months postoperatively. We measured the internal diameter of the femoral bone tunnel at 5 mm from the intra-articular outlet of the femoral bone tunnel on an MRI scan image perpendicular to the femoral bone tunnel. The size of the tunnel was compared between the intraoperative drilling of the bone tunnel and the size of the bone tunnel at 6 months postoperatively. Postoperative clinical assessment was Lysholm score.

RESULTS

After a 6-month follow-up of 40 patients, the diameter of the femoral tunnel at a distance of 5 mm from the inner opening of the femoral tunnel was 10.96 ± 0.67 mm and 10.11 ± 0.62 mm in patients of group N and group R, respectively, and the difference was statistically significant (P < 0.05).The diameter of the femoral tunnel at 6 months postoperatively in group N and group R compared to the intraoperative bone tunnel increased by 2.58 ± 0.24 mm and 1.94 ± 0.31 mm, and the difference was statistically significant (P < 0.05).The femoral tunnel enlargement rates of group N and group R were 30.94 ± 3.00% and 24.02 ± 5.10%, respectively, and the differences were significant (P < 0.05).

CONCLUSION

ACL femoral side retained stump technique does not sacrifice the ideal location of the femoral tunnel and is able to preserve the possible benefits of the ACL stump: reduced femoral tunnel enlargement.

Evaluation of Anterior Tibial Translation Under Physiological Axial Load After ACL Reconstruction With Lateral Extra-articular Tenodesis

Background

Postoperative laxity correlates with negative clinical outcomes after anterior cruciate ligament reconstruction (ACLR). The influence of lateral extra-articular tenodesis (LET) on anteroposterior translation is unclear.

Purpose/Hypothesis

This study aimed to evaluate the reduction in radiographic static anterior tibial translation (SATT) and dynamic anterior tibial translation (DATT) after LET as an adjunctive procedure to ACLR. It was hypothesized that adding a LET procedure would have no effect on postoperative SATT and DATT.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent primary ACLR with hamstring tendon autografts between 2020 and 2022 were reviewed, and those who underwent ACLR and LET as an anterolateral associate procedure were paired 1 to 1 with those who underwent isolated ACLR (control) based on age, sex, preoperative SATT, and posterior tibial slope (PTS). The indications for LET were age <18 years and anterolateral rotary instability (grade ≥2 pivot shift). A previously validated technique was used to measure SATT, DATT, and PTS on lateral weightbearing and lateral stress knee radiographs. Preoperative and 9-month postoperative radiographs were compared between the 2 groups.

Results

A total of 72 patients were included in the analysis (n = 36 patients in each group). The inter- and intraobserver reliability of the SATT, DATT, and PTS measurements was excellent (intraclass correlation coefficients, 0.88-0.99). The mean pre- and postoperative SATT in the ACLR+LET group was 2.44 ± 2.90 mm and 2.44 ± 2.38 mm, respectively, compared with 2.60 ± 2.99 mm and 2.12 ± 2.74 mm, respectively, in the control group. The mean pre- and postoperative reduction in side-to-side DATT in the ACLR+LET group was 5.44 ± 4.65 mm and 1.13 ± 2.95 mm, respectively, compared with 5.03 ± 3.66 mm and 2 ± 3.12 mm, respectively, in the control group. There was no pre- to postoperative difference in SATT (P = .51). However, the side-to-side DATT was reduced by 3.66 ± 3.37 mm postoperatively (P < .001), without significant differences between groups (P = .24).

Conclusion

Including a LET procedure for patients undergoing ACLR did not reduce SATT; that is, it did not decrease the amount of tibial translation due to physiological axial load.

Comparison of Side-to-Side Difference in Posterior Tibial Slope in Knees With Acute Versus Chronic Anterior Cruciate Ligament Deficiency

Background

The posterior tibial slope (PTS) is an important feature in knee joint biomechanics and indicates anterior-posterior knee stability. Increased PTS is a known risk factor for both primary anterior cruciate ligament (ACL) rupture and postreconstruction rerupture.

Purpose

To investigate the effect of long-term exposure to ACL deficiency on the PTS and the sagittal anatomy of the proximal tibia.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 44 patients (38 men, 6 women) with a history of knee injury and ACL rupture confirmed by magnetic resonance imaging and physical examination were included in this study. Patients were divided into those with chronic ACL deficiency (group 1: injured ≥5 years prior; n = 22) and acute ACL deficiency (group 2: injured <1 year prior; n = 22). The medial and lateral tibial plateau PTS and anterior tibial translation were measured on monopodal weightbearing knee radiographs at 20° of flexion. The mechanical tibiofemoral angle (MTFA) and the medial proximal tibial angle (MPTA) were measured using an orthoroentgenogram. The side-to-side difference between the affected and unaffected knees was also calculated for all measurements.

Results

The mean duration of exposure to ACL deficiency was 7.6 years (range, 5-15 years) in group 1 and 4.4 months (range, 1-11 months) in group 2. Regarding the side-to-side differences in angular measurements, a higher medial PTS (affected vs unaffected: 12.4° vs 10.1°; P = .007), higher lateral PTS (11° vs 8.9°; P = .011), and increased varus alignment on both the MTFA (4.3° vs 2.4°; P = .036) and the MPTA (84.9° vs 86.3°; P = .033) were found in group 1, while no significant differences in angular measurements were found in group 2. Compared with group 2, patients in group 1 had a significantly higher side-to-side difference in the medial PTS (2.3° vs 0.1°; P = .0001), lateral PTS (2.1° vs 0.4°; P = .0001), and MPTA (1.4° vs 0.1°; P = .002).

Conclusion

This study showed that the affected knees of patients with chronic ACL deficiency (≥5 years) had higher medial and lateral PTS compared with the unaffected contralateral knees. Therefore, when planning ACL reconstruction for patients with a history of long-term ACL deficiency, it is crucial to measure the preoperative PTS accurately.

Evaluation of Failed ACL Reconstruction: An Updated Review

Failure rates among primary Anterior Cruciate Ligament Reconstruction (ACLR) range from 3.2% to 11.1%. Recently, there has been increased focus on surgical and anatomic considerations which predispose patients to failure, including excessive posterior tibial slope (PTS), unaddressed high-grade pivot shift, and improper tunnel placement. The purpose of this review was to provide a current summary and analysis of the literature regarding patient-related and technical factors surrounding revision ACLR, rehabilitation considerations, overall outcomes and return to sport (RTS) for patients who undergo revision ACLR. There is a convincingly higher re-tear and revision rate in patients who undergo ACLR with allograft than autograft, especially amongst the young, athletic population. Unrecognized Posterior Cruciate Ligament (PLC) injury is a common cause of ACLR failure and current literature suggests concurrent operative management of high-grade PLC injuries. Given the high rates of revision surgery in young active patients who return to pivoting sports, the authors recommend strong consideration of a combined ACLR + Anterolateral Ligament (ALL) or Lateral extra-articular tenodesis (LET) procedure in this population. Excessive PTS has been identified as an independent risk factor for ACL graft failure. Careful consideration of patient-specific factors such as age and activity level may influence the success of ACL reconstruction. Additional technical considerations including graft choice and fixation method, tunnel position, evaluation of concomitant posterolateral corner and high-grade pivot shift injuries, and the role of excessive posterior tibial slope may play a significant role in preventing failure.

Interference Screw versus Cement Fixation in Anterior Cruciate Ligament Soft Tissue Grafts: A Biomechanical Study

Shortcomings of fixation have been reported as a source of graft failure in anterior cruciate ligament (ACL) reconstruction. While interference screws have long been used as fixation devices for ACL reconstruction, they are not without complications. Previous studies have highlighted the use of bone void filler as a fixation method; however, no biomechanical comparisons using soft tissue grafts with interference screws exist to our knowledge. The purpose of this study is to evaluate the fixation strength of a calcium phosphate cement bone void filler compared with screw fixation in an ACL reconstruction bone replica model with human soft tissue grafts. In total, 10 ACL grafts were constructed using semitendinosus and gracilis tendons harvested from 10 donors. Grafts were affixed with either an 8-10 mm × 23 mm polyether ether ketone interference screw (n = 5) or with approximately 8 mL of calcium phosphate cement (n = 5) into open cell polyurethane blocks. Graft constructs were tested to failure in cyclic loading under displacement control at a rate of 1 mm per second. When compared with screw construct, the cement construct showed a 978% higher load at yield, 228% higher load at failure, 181% higher displacement at yield, 233% higher work at failure, and a 545% higher stiffness. Normalized data for the screw constructs relative to the cement constructs from the same donor showed 14 ± 11% load at yield, 54 ± 38% load at failure, and 172 ± 14% graft elongation. The results of this study indicate that cement fixation of ACL grafts may result in a stronger construct compared with the current standard of fixation with interference screws. This method could potentially reduce the incidence of complications associated with interface screw placement such as bone tunnel widening, screw migration, and screw breakage.

Anterior Cruciate Ligament Repair Using a Re-tensionable All-Suture Construct

Anterior cruciate ligament (ACL) tears are among the most common injuries to the knee. With recent improvements in imaging that allow for more precise identification of ACL tear patterns, improved techniques for repair, and advancements in biological augmentation, there has been a re-emerging interest in primary ACL repair, especially for acute proximal ACL tears. This article aims to describe a surgical technique for primary ACL repair using a re-tensionable all-suture-based construct.

Radiographic Investigation of Coronal Plane and Patellar Height and Changes Following Tibial Deflection Osteotomy for Correction of Tibial Slope in Combination With ACL Reconstruction

BACKGROUND

A tibial deflexion osteotomy (TDO) is performed to decrease the sagittal tibial slope to reduce the relative risk of anterior cruciate ligament (ACL) reconstruction (ACLR) graft failure. Given that coronal plane osteotomies can cause consequential changes in the sagittal plane to patellar height and tibial slope, potential changes to coronal plane alignment and patellar height can result after a sagittal plane osteotomy.

PURPOSE

To compare preoperative and postoperative coronal plane alignment after TDO, as well as to analyze the effect of the osteotomy on patellar height.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study was conducted on a consecutive series of patients with primary and revision ACLR with concomitant TDO between 2011 and 2022. Inclusion criteria were 1-stage autograft ACLR combined with supratubercular TDO with pre- and 3 months postoperative radiographs of sufficient quality. Indications for TDO were anterior instability requiring ACL revision surgery and a posterior tibial slope (PTS) >9° or a PTS >14° in the primary ACL surgery patients. Anteroposterior and lateral knee radiographs were reviewed, and the medial proximal tibial angle (MPTA), PTS, Caton-Deschamps index (CDI), and modified Insall-Salvati ratio were measured directly from the radiographs by 2 independent reviewers.

RESULTS

A total of 68 patients were included in this study. Pre- and postoperative radiographs were performed 1 month before and 3 months after surgery, respectively. There was a significant increase in the mean MPTA of 0.95° varus (SD, 2.1°; range, increase of 4.23° valgus to increase of 7.74° varus; P < .01), a decreased PTS of 8.86° (SD, 3.03°; P < .01), and an increased CDI of 0.08 (range, decrease of 0.27 to increase of 0.64) (P < .01; SD, 0.17) in patients undergoing TDO. Insall-Salvati ratio measurements showed no difference. There was good intra- and interobserver reliability, with intraclass correlation coefficients of 0.97 and 0.91 for MPTA, 0.97 and 0.87 for PTS, 0.87 and 0.93 for CDI, and 0.88 and 0.76 the Insall-Salvati ratio.

CONCLUSION

This study, the largest series on TDO for ACLR, demonstrates that the TDO can be performed safely without large changes to coronal alignment or patellar height. The tibial slope was reduced by a mean of 8.86° (range, 2.3°-11.5°; P < .01). The TDO produces a small statistically significant change to coronal alignment, inducing a mean increased varus of <1° and an increased patellar height of 0.1 CDI. Therefore, TDO can be performed safely without dramatic changes to coronal alignment or patellar height, this study highlights technical aspects to minimize iatrogenic varus.

Radiographic Investigation of Differences in Static Anterior Tibial Translation With Axial Load Between Isolated ACL Injury and Controls

BACKGROUND

Static anterior tibial translation (SATT) is radiographically measured to show the amount of tibial translation during the single-leg stance, and thus it is representative of the physiological axial load subjected to the anterior cruciate ligament (ACL) during the stance. Increased SATT has been associated with increased posterior tibial slope (PTS) and is also associated with increased graft failure.

PURPOSE

To compare the SATT value in a control population with that in a population with an isolated ACL injury, as well as to compare the effect of tibial slope on SATT between the 2 groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A consecutive series of patients without ligamentous or meniscal injuries between 2019 and 2022 was reviewed. A matched consecutive cohort of patients with nonacute ACL injuries (surgery between 6 and 12 weeks after injury) without concomitant pathology was reviewed. Preoperative SATT and PTS were measured with a previously validated technique on lateral weightbearing knee radiographs. The SATT value was determined, and regression analysis was performed to investigate the relationship between SATT and PTS.

RESULTS

In total, 101 controls and 115 patients with an ACL injury were included in this study. The mean SATT was 1.31 mm (SD, 2.44 mm) and the mean PTS was 10.61° (SD, 3.28°) in the control cohort. The SATT was larger (mean, 2.27 mm; SD, 3.36 mm) in the ACL-injured cohort despite the tibial slope measurement being less in the ACL-injured cohort (mean, 9.46°; SD, 2.85°; P = .016). Linear regression analysis showed that for every 1° of increase in PTS, there was a 0.34-mm increase in SATT in the control cohort; however, there was a greater increase of 0.5 mm for every 1° of increase in PTS in the ACL-injured cohort. We found no significant differences in SATT when the cohorts were compared by age (P = .26) or sex (P = .10).

CONCLUSION

The present study reports a reference SATT value of 1.31 mm (SD, 2.44 mm) in a non-ACL-injured cohort, which was lower than in the ACL-injured cohort (mean, 2.27 mm; SD, 3.36 mm). The effect of slope on weightbearing anterior tibial translation was greater in the ACL-injured population than in the control cohort.

Role of Lateral Extra-articular Tenodesis in Restraining Internal Tibial Rotation: In Vitro Biomechanical Assessment of Lateral Tissue Engagement

BACKGROUND

The way in which force increases in the anterolateral tissues and the lateral extra-articular tenodesis (LET) tissue to resist internal rotation (IR) of the tibia after anterior cruciate ligament (ACL) reconstruction in isolation and after LET augmentation, respectively, is not well understood.

PURPOSE

(1) To compare in a cadaveric model how force increases (ie, engages) in the anterolateral tissues with IR of the tibia after isolated ACL reconstruction and in the LET tissue after augmentation of the ACL reconstruction with LET and (2) to determine whether IR of the tibia is related to engagement of the LET tissue.

STUDY DESIGN

Controlled laboratory study.

METHODS

IR moments were applied to 9 human cadaveric knees at 0°, 30°, 60°, and 90° of flexion using a robotic manipulator. Each knee was tested in 2 states: (1) after isolated ACL reconstruction with intact anterolateral tissues and (2) after LET was performed using a modified Lemaire technique with the LET tissue fixed at 60° of flexion under 44 N of tension. Resultant forces carried by the anterolateral tissues and the LET tissue were determined via superposition. The way force increased in these tissues was characterized via parameters of tissue engagement, namely in situ slack, in situ stiffness, and tissue force at peak applied IR moment, and then compared (α < .05). IR was related to parameters of engagement of the LET tissue via simple linear regression (α < .05).

RESULTS

The LET tissue exhibited less in situ slack than the anterolateral tissues at 30°, 60°, and 90° of flexion (P≤ .04) and greater in situ stiffness at 30° and 90° of flexion (P≤ .043). The LET tissue carried greater force at the peak applied IR moment at 0° and 30° of flexion (P≤ .01). IR was related to the in situ slack of the LET tissue (R2≥ 0.88; P≤ .0003).

CONCLUSION

LET increased restraint to IR of the tibia compared with the anterolateral tissue, particularly at 30°, 60°, and 90° of flexion. IR of the tibia was positively associated with in situ slack of the LET tissue.

CLINICAL RELEVANCE

Fixing the LET at 60° of flexion still provided IR restraint in the more functionally relevant flexion angle of 30°. Surgeons should pay close attention to the angle of internal and/or external tibial rotation when fixing the LET tissue intraoperatively because this surgical parameter is related to in situ slack of the LET tissue and, therefore, the amount of IR of the tibia.

The Original Technique for Tibial Deflexion Osteotomy During Revision Anterior Cruciate Ligament Reconstruction: Surgical Technique

The original technique for tibial deflexion osteotomy (TDO) was first described by Henri Dejour during the Lyon knee meeting in 1991 to reduce excessive posterior tibial slope during second revision anterior cruciate ligament reconstruction (ACLR). The technique is nowadays increasingly performed during first-revision ACLR in patients at risk for graft retear. This Technical Note describes and updates the original TDO technique.

Double and Single Bundle in Athletes: A Comparison in Medium and Long-Term Rates to Return to Sport and Re-Injury

Objectives

Compare, retrospectively, the medium- and long-term of return to sport rates and re-injury of the anterior cruciate ligament (ACL) in patients submitted to single-bundle (SB) compared to double-bundle (DB) technique reconstruction.

Methods

Athletes operated by SB or DB ACL reconstruction, with at least five years of follow-up at a single center, were included. The following data were collected: demographic data; competitive sports practice before the injury; previous surgery; injury/surgery to the contralateral knee; return to sports and level of the return; re-injury (time of the re-injury after the first surgery; mechanism of trauma for the re-injury; necessity of operative treatment); signs and complaints related to the knee the last clinical consultation.

Results

Seventy-six athletes (27 SB and 49 DB) were included. The return to sport rate (98%) was the same for both groups, and the return to the previous level rate showed an improvement in the DB group but without statistical significance (63% vs. 79%; P = 0.173). However, other outcomes showed higher results for the DB group: lower re-injury rate throughout the follow-up period (41% vs. 18%; P = 0.034) and during the first year of follow-up (22% vs. 4%; P = 0.021), and less stiffness (0% vs. 22%, P = 0.001). While in primary reconstruction cases, there was not a higher re-injury rate using SB (P = 0.744), in the revision cases, SB was correlated with more re-injuries than DB (P = 0.002).

Conclusion

The overall re-injury in the medium- and long-term and the return to practice sports at the same level as before surgery in athletes submitted to DB reconstruction were slightly better than those submitted to SB reconstruction, especially in the cases that were asecond time lesion ( revisioned knees).

Enthesis maturation in engineered ligaments is differentially driven by loads that mimic slow growth elongation and rapid cyclic muscle movement

Entheses are complex attachments that translate load between elastic-ligaments and stiff-bone via organizational and compositional gradients. Neither natural healing, repair, nor engineered replacements restore these gradients, contributing to high re-tear rates. Previously, we developed a culture system which guides ligament fibroblasts in high-density collagen gels to develop early postnatal-like entheses, however further maturation is needed. Mechanical cues, including slow growth elongation and cyclic muscle activity, are critical to enthesis development in vivo but these cues have not been widely explored in engineered entheses and their individual contribution to maturation is largely unknown. Our objective here was to investigate how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, individually drive enthesis maturation in our system so to shed light on the cues governing enthesis development, while further developing our tissue engineered replacements. Interestingly, we found these loads differentially drive organizational maturation, with slow stretch driving improvements in the interface/enthesis region, and cyclic load improving the ligament region. However, despite differentially affecting organization, both loads produced improvements to interface mechanics and zonal composition. This study provides insight into how mechanical cues differentially affect enthesis development, while producing some of the most organized engineered enthesis to date. STATEMENT OF SIGNIFICANCE: Entheses attach ligaments to bone and are critical to load transfer; however, entheses do not regenerate with repair or replacement, contributing to high re-tear rates. Mechanical cues are critical to enthesis development in vivo but their individual contribution to maturation is largely unknown and they have not been widely explored in engineered replacements. Here, using a novel culture system, we provide new insight into how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, differentially affect enthesis maturation in engineered ligament-to-bone tissues, ultimately producing some of the most organized entheses to date. This system is a promising platform to explore cues regulating enthesis formation so to produce functional engineered replacements and better drive regeneration following repair.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus: part II-surgical strategy

PURPOSE

The aim of this ESSKA consensus is to give recommendations based on scientific evidence and expert opinion to improve the diagnosis, preoperative planning, indication and surgical strategy in Anterior Cruciate Ligament revision.

METHODS

Part 2, presented herein, followed exactly the same methodology as Part 1: the so-called ESSKA formal consensus derived from the Delphi method. Eighteen questions were ultimately asked. The quality of the answers received the following grades of recommendation: Grade A (high level scientific support), Grade B (scientific presumption), Grade C (low level scientific support) or Grade D (expert opinion). All answers were scored from 1 to 9 by the raters. Once a general consensus had been reached between the steering and rating groups, the question-answer sets were submitted to the peer-review group. A final combined meeting of all the members of the consensus was then held to ratify the document.

RESULTS

The review of the literature revealed a rather low scientific quality of studies examining the surgical strategy in cases of ACL reconstruction failure. Of the 18 questions, only 1 received a Grade A rating; 5, a Grade B rating; and 9, grades of C or D. The three remaining complex questions received further evaluations for each portion of the question and were looked at in more detail for the following grades: B and D; A, C and D; or A, B, C and D. The mean rating of all questions by the rating group was 8.0 + - 1.1. The questions and recommendations are listed in the article.

CONCLUSION

ACL revision surgery, especially the surgical strategy, is a widely debated subject with many different opinions and techniques. The literature reveals a poor level of standardization. Therefore, this international European consensus project is of great importance and clinical relevance for guiding the management of ACL revision in adults.

LEVEL OF EVIDENCE

Level II.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus part I-diagnostics and preoperative planning

PURPOSE

The aim of this ESSKA consensus is to give recommendations based on evidence and expert opinion to improve diagnosis, preoperative planning, indication and surgical strategy in ACL revision.

METHODS

The European expert surgeons and scientists were divided into four groups to participate in this consensus. A "literature group" (four surgeons); "steering group" (14 surgeons and scientists); "rating group" (19 surgeons) and finally "peer review group" (51 representatives of the ESSKA-affiliated national societies from 27 countries). The steering group prepared eighteen question-answer sets. The quality of the answers received grades of recommendation ranging from A (high-level scientific support), to B (scientific presumption), C (low level scientific support) or D (expert opinion). These question-answer sets were then evaluated by the rating group. All answers were scored from 1 to 9. The comments of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the question-answer sets were submitted to the peer review group. A final combined meeting of all the members of the consensus was held to ratify the document.

RESULTS

The literature review for the diagnosis and preoperative planning of ACL revision revealed a rather low scientific quality. None of the 18 questions was graded A and six received a grade B. The mean rating of all the questions by the rating group was 8.4 ± 0.3. The questions and recommendations are listed below.

CONCLUSION

ACL revision surgery is a widely debated subject with many different opinions and techniques. The literature reveals a poor level of standardisation. Therefore, this international consensus project is of great importance.

LEVEL OF EVIDENCE

II.

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.

Combined anterior cruciate ligament revision with reconstruction of the antero-lateral ligament does not improve outcome at 2-year follow-up compared to isolated acl revision; a randomized controlled trial

PURPOSE

It is essential to obtain rotational stability of the knee after anterior cruciate ligament reconstruction (ACL-R) and it is suggested that a supplementary reconstruction of the antero-lateral ligament (ALL-R) may supports this. Theoretically, ALL-R may be particularly advantageous to support revision of failed ACL-Rs. It was hypothesized that ACL revision combined with ALL-R will result in superior outcome compared to isolated ACL revision.

METHODS

The study was designed as a randomized controlled trial. Patients eligible for first time ACL revision were randomized to either isolated ACL revision (- ALL group) or ACL revision combined with a single-stranded allograft ALL-reconstruction (+ ALL group). Patient reported outcomes and function were evaluated at two-year follow-up by KNEES-ACL, KOOS, and Tegner activity scale. Objective knee laxity was evaluated at one-year follow-up using an instrumented Rolimeter test, the pivot shift test, and a manual Lachman test.

RESULTS

A total of 103 patients were enrolled with 49 patients randomized to the + ALL group and 54 patients in the - ALL group. There were no differences at baseline between groups regarding age, gender, body mass index, preoperative patient reported outcome scores and concomitant meniscus or cartilage injury. The ACL revision was performed with an allograft in 10 patients (20%) in the + ALL group and 8 patients (15%) in the -ALL group. At follow-up there was no significant difference between the groups in patient reported outcome scores and clinical knee laxity.

CONCLUSION

Supplementary ALL-R does not improve subjective outcome of first time ACL revision at two-years and clinical knee stability at one-year follow-up compared to isolated ACL revision.

LEVEL OF EVIDENCE

Level I.

Failure Rates and Complications After Multiple-Revision ACL Reconstruction: Comparison of the Over-the-Top and Transportal Drilling Techniques

Background

Multiple-revision anterior cruciate ligament reconstruction (ACLR) presents several technical challenges, often due to residual hardware, tunnel widening, malposition, or staged surgeries.

Purpose

To compare failure and complication rates between the over-the-top (OTT) and transportal drilling (TD) techniques in patients undergoing surgery for failed revision ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

The medical records of patients with at least 2 revision ACLRs using either the OTT or TD technique were reviewed retrospectively. Data on patient demographics, graft characteristics, number of revisions, concomitant procedures, complications, and failures were collected. Between-group comparisons of continuous and categorical variables were conducted with the independent-samples t test and the Fisher exact or chi-square test, respectively.

Results

A total of 101 patients undergoing multiple-revision ACLR with OTT (n = 37, 37%) and TD (n = 64, 63%) techniques were included for analysis. The mean follow-up time was 60 months (range, 12-196 months). There were no significant differences in age, sex, body mass index, laterality, or follow-up length between groups (P > .05). Allograft was the graft used most frequently (n = 64; 67.3%) with no significant differences between groups in graft diameter (P > .05). There were no statistically significant differences between groups regarding rate of concurrent medial and lateral meniscus, cartilage, or lateral extra-articular procedures (P > .05). There was also no significant66 between-group difference in complication rate (OTT: n = 2 [5.4%]; TD: n = 8 [13%]) or graft failure rate (OTT: n = 4 [11%]; TD: n = 14 [22%]) (P > .05 for both).

Conclusion

The results of this study showed notably high failure and complication rates in challenging multiple-revision ACLR. Complication and failure rates were similar between techniques, demonstrating that the OTT technique is a valuable alternative that can be used in a revision ACLR, particularly as a single-stage approach when the single-stage TD technique is not possible.

Clinical outcomes and return to sport after single-stage revision anterior cruciate ligament reconstruction by bone-patellar tendon autograft combined with lateral extra-articular tenodesis

PURPOSE

The anterior cruciate ligament reconstruction (ACLR) failure rate continues to increase. Involvement of a young population with a desire to return to sport, explains the increased need for ACLR (revACLR) revision. The aim of this study was to evaluate clinical outcome, complications, failure rate and return to sport of a single-stage revACLR using bone patellar tendon-bone (BTBT) combined with lateral extra-articular tenodesis (LET).

MATERIAL AND METHODS

A retrospective analysis was performed on 36 patients who underwent revACLR. Knee stability was assessed by Lachman and Pivot shift test. Objective anterior laxity was determined by KT-2000 arthrometer. The IKDC subjective, Lysholm, ACL-RSI Scores, level of sport activity and Forgotten Joint Score-12 were recorded.

RESULTS

Of 36 patients, we collected data from 17 who underwent single-stage revACLR with autologous BTBT combined with LET, performed using an extra-articular MacIntosh procedure as modified by Arnold-Coker. The side-to-side difference in Lachman test and Pivot shift test significantly improved postoperatively. The subjective IKDC, Lysholm and ACL-RSI significantly improved from 71.4 ± 9.03 to 92 ± 6.9, from 58.3 ± 19.3 to 66.8 ± 27.7 and from 50.4 ± 12.2 to 68.6 ± 24.5, respectively during the post-operative follow-up. Ten patients (58.8%) returned to their desired level of sport. One patient was considered a failure because of the postoperative laxity.

CONCLUSION

Single-stage revACLR with BPTB combined with LET is a safe procedure that shows good objective and subjective outcomes, and a high rate of return to the same level of sport. Reducing rotational instability and strain on intra-articular reconstructed structures results in a low rate of complications and failure.

Anterior cruciate ligament failure and management

Anterior cruciate ligament (ACL) reconstruction failure can be defined as abnormal knee function due to graft insufficiency with abnormal laxity or failure to recreate a functional knee according to the expected outcome. Traumatic ruptures have been reported as the most common reason for failure. They are followed by technical errors, missed concomitant knee injuries, and biological failures. An in-depth preoperative examination that includes a medical history, clinical examinations, advanced imaging, and other appropriate methods is of utmost importance. There is still no consensus as to the ideal graft, but autografts are the favorite choice even in ACL revision. Concomitant meniscal treatment, ligamentous reconstruction, and osteotomies can be performed in the same surgical session to remove anatomical or biomechanical risk factors for the failure. Patient expectations should be managed since outcomes after ACL revision are not as good as those following primary ACL reconstruction.

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.

Propensity for Clinically Meaningful Improvement and Surgical Failure After Anterior Cruciate Ligament Repair

Background

Primary repair of the anterior cruciate ligament (ACL) confers an alternative to ACL reconstruction in appropriately selected patients.

Purpose

To prospectively assess survivorship and to define the clinically meaningful outcomes after ACL repair.

Study Design

Case series; Level of evidence, 4.

Methods

Included were consecutive patients with Sherman grade 1-2 tears who underwent primary ACL repair with or without suture augmentation between 2017 and 2019. Patient-reported outcomes (Lysholm, Tegner, International Knee Documentation Committee, Western Ontario and McMaster Universities Osteoarthritis Index, and Knee injury and Osteoarthritis Outcome Score [KOOS] subscales) were collected preoperatively and at 6 months, 1 year, and 2 years postoperatively. The minimal clinically important difference (MCID) was calculated using a distribution-based method, whereas the Patient Acceptable Symptom State (PASS) and substantial clinical benefit (SCB) were calculated using an anchor-based method. Plain radiographs and magnetic resonance imaging (MRI) were obtained at 6 months, 1 year, and 2 years postoperatively.

Results

A total of 120 patients were included. The overall failure rate was 11.3% at 2 years postoperatively. Changes in outcome scores required to achieve the MCID ranged between 5.1 and 14.3 at 6 months, 4.6 and 8.4 at 1 year, and 4.7 and 11.9 at 2 years postoperatively. Thresholds for PASS achievement ranged between 62.5 and 89 at 6 months, 75 and 89 at 1 year, and 78.6 and 93.2 at 2 years postoperatively. Threshold scores (absolute/change based) for achieving the SCB ranged between 82.8 and 96.4/17.7 and 40.1 at 6 months, between 94.7 and 100/23 and 45 at 1 year, and between 95.3 and 100/29.4 and 45 at 2 years. More patients achieved the MCID and PASS at 1 year compared with 6 months and 2 years. For SCB, this trend was also observed for non-KOOS outcomes, while for KOOS subdomains, more patients achieved the SCB at 2 years. High-intensity signal of the ACL repair (odds ratio [OR], 31.7 [95% CI, 1.5-73.4]; P = .030) and bone contusions on MRI (OR, 4.2 [95% CI, 1.7-25.2]; P = .041) at 1 year postoperatively were independently associated with increased risk of ACL repair failure.

Conclusion

The rate of clinically meaningful outcome improvement was high early after ACL repair, with the greatest proportion of patients achieving the MCID, PASS, and SCB at 1 year postoperatively. Bone contusions involving the posterolateral tibia and lateral femoral condyle as well as high repair signal intensity at 1 year postoperatively were independent predictors of failure at 2 years postoperatively.

External stimulation: A potential therapeutic strategy for tendon-bone healing

Injuries at the tendon-bone interface are very common in the field of sports medicine, and healing at the tendon-bone interface is complex. Injuries to the tendon-bone interface can seriously affect a patient’s quality of life, so it is essential to restore stability and promote healing of the tendon-bone interface. In addition to surgical treatment, the healing of tendons and bones can also be properly combined with extracorporeal stimulation therapy during the recovery process. In this review, we discuss the effects of extracorporeal shock waves (ESWs), low-intensity pulsed ultrasound (LIPUS), and mechanical stress on tendon-bone healing, focusing on the possible mechanisms of action of mechanical stress on tendon-bone healing in terms of transcription factors and biomolecules. The aim is to provide possible therapeutic approaches for subsequent clinical treatment.

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.

A comparison of the outcomes of anterior curciate ligament reconstruction with large-size graft versus reconstruction with average-size graft combined with extraarticular tenodesis

INTRODUCTION

Many patients who have had anterior cruciate ligament (ACL) reconstruction (R) complain of instability, inability to return to previous levels of sports activity, and possible ACL graft failure. Graft size was discovered to be an important factor in lowering ACL failure rates. Also, extraarticular tenodesis decreases recurrent instability, A comparative study was done to compare the effect of graft size and lateral external tenodesis on the recurrence of instability after ACL-R.

PATIENTS AND METHODS

A Prospective Blinded Randomized Controlled study included 100 consecutive patients who underwent ACL-R with hamstring tendon grafts in our Hospital. The patients were allocated into two groups (Group A and B) with randomization; group A received ACL-R with a large-size ACL-graft diameter of 6 strands, and group B received ACL-R of 4 strands combined with lateral extraarticular tenodesis (LET) (Modified Lemaire). Each group had fifty patients. The follow-up time was two years. They were examined for graft failure, anterolateral rotatory instability with the pivot shift test, and clinical outcomes, which were evaluated with the International Knee Documentation Committee score (IKDC) both subjective and objective.

RESULTS

In this study; group A, graft failure occurred in three (6.3%) patients, a positive pivot shift test grade I was detected in eight (17.8%) patients, grade II in three (6.7%) patients, and grade III in one (2.2%) patient. The subjective IKDC score was 87.9 (± 7.19) points. The objective IKDC score was normal or nearly normal in 43 (93.4%) patients. In group B, one (2.1%) patient had graft failure, five (10.9%) had a positive pivot shift test grade I, one (2.1%) had a grade II, and no patient had a grade III. The subjective IKDC score was 91.9 (± 8.9) points. The objective IKDC score was normal or nearly normal in 44 (95.6%) patients. As regard the subjective IKDC score, there was a non-significant difference between both groups (p value = 0.465).

CONCLUSION

Both groups showed a low ACL-graft failure rate, low anterolateral rotatory instability, and a good clinical outcome. Although there was no significant difference in subjective IKDC score between both groups, the failure rate and anterolateral rotatory instability were significantly lower in the ACL-R (4 strands) with LET combination group than in the group with the large-diameter (6 strands) graft.

LEVEL OF EVIDENCE

Level 1; Randomized Comparative Study.

Tunnel Management in Revision Anterior Cruciate Ligament Reconstruction: Current Concepts

Bone tunnel-related complications are frequently encountered during revision anterior cruciate ligament reconstruction (ACLR). Issues with tunnel positioning, enlargement, containment, and hardware interference may complicate surgery and compromise outcomes. As a result, several strategies have emerged to address these issues and optimize results. However, a systematic, unified approach to tunnel pathology in revision ACLR is lacking. The purpose of this review is to highlight the current state of the literature on bone tunnel complications and, although extensive literature on the subject is lacking, present an updated approach to the evaluation and management of tunnel-related issues in revision ACLR.

Biologics, Stem Cells, Growth Factors, Platelet-Rich Plasma, Hemarthrosis, and Scaffolds May Enhance Anterior Cruciate Ligament Surgical Treatment

Biologics including mesenchymal stem cells (MSCs), growth factors, and platelet-rich plasma may enhance anterior cruciate ligament (ACL) reconstruction and even ACL primary repair. In addition, hemarthrosis after acute ACL injury represents a source of biologic factors. MSCs can differentiate into both fibroblasts and osteoblasts, potentially providing a transition between the ligament or graft and bone. MSCs also produce cytokines and growth factors necessary for cartilage, bone, ligament, and tendon regeneration. MSC sources including bone marrow, synovium, adipose tissue, ACL-remnant, patellar tendon, and umbilical cord. Also, scaffolds may represent a tool for ACL tissue engineering. A scaffold should be porous, which allows cell growth and flow of nutrients and waste, should be biocompatible, and might have mechanical properties that match the native ACL. Scaffolds have the potential to deliver bioactive molecules or stem cells. Synthetic and biologically derived scaffolds are widely available. ACL reconstruction with improved outcome, ACL repair, and ACL tissue engineering are promising goals. LEVEL OF EVIDENCE: Level V, expert opinion.

Re-rupture rate and the post-surgical meniscal injury after anterior cruciate ligament reconstruction with the Press-Fit-Hybrid®-technique in comparison to the interference screw technique: a retrospective analysis of 200 patients with at least 3 years follow-up

BACKGROUND

There is currently no consensus regarding the preferred surgical procedure for the reconstruction of anterior cruciate ligament (ACL). The interference screw technique is widely used, but has been associated with a risk of graft damage. The Press-Fit-Hybrid®-technique is one of the alternatives for biological ACL-reconstruction with minimal implant requirements. The hypothesis of this retrospective analysis is, that the Press-Fit-Hybrid®-technique leads to better results with respect to re-rupture rate and secondary meniscal lesion than the interference-screw-technique.

METHODS

To compare the re-rupture rate of the interference-screw-technique (IF) used until 2015 with the currently used Press-Fit-Hybrid®-technique (PFH), the last 100 patients of the IF-group and the first 100 patients of the PFH-group were retrospectively analyzed. Primary outcomes were re-rupture rate, complications and secondary meniscal injury. Additionally, laxity, Lachman and Pivot-shift and range of motion were evaluated.

RESULTS

A mean follow-up of 4.2 and 5.3 years revealed 4% and 9% re-rupture rates and 1% and 2% complication rates in the PFH- and IF-group, respectively. In the PFH-group there were no re-ruptures in patients older than 23 years. Secondary meniscal injury post-surgery was 6% and 9% for the PFH and IF-group, respectively. Knee stability was similar in both groups. Range of motion was significantly better in the PFH-group, with 136° of flexion, 6 months after surgery.

CONCLUSION

For ACL-reconstruction the Press-Fit-Hybrid®-technique is an alternative new method. Low level of secondary meniscal lesions after surgery and high stability, is known to prevent later arthrosis of the knee. The encouraging observed trend of the reduction of the re-rupture rate in revision surgery and in young patients using the Press-Fit-Hybrid®-technique in comparison to the interference-screw-technique must be confirmed with further studies.

LEVEL OF EVIDENCE

Therapeutic Level III, retrospective cohort study.

Double-bundle non-anatomic ACL revision reconstruction with allograft resulted in a low revision rate at 10 years

PURPOSE

This study aimed at reporting the long-term second revision rate and subjective clinical outcomes from a cohort of patients who underwent a double-bundle (DB) ACLR first revision with allograft at a single institution.

METHODS

The Institutional database was searched according to the following inclusion criteria: (1) patients that underwent DB-ACL first revision with Achilles tendon allograft, (2) surgery performed between January 2000 and December 2012, (3) age at revision ≥ 18 y/o. Patients' general information, history, surgical data, and personal contacts were extracted from charts. An online survey platform was implemented to collect responses via email. The survey questions included: date of surgeries, surgical data, date of graft failure and subsequent second ACL revision surgery, any other surgery of the index knee, contralateral ACLR, KOOS score, and Tegner scores.

RESULTS

Eighty-one patients were included in the survival analysis, mean age at revision 32 ± 9.2 y/o, 71 males, mean BMI 24.7 ± 2.7, mean time from ACL to revision 6.8 ± 5.4 years, mean follow-up time 10.7 ± 1.4 years. There were 12 (15%) second ACL revisions during the follow-up period, three females and nine males, at a mean of 4.5 ± 3 years after the index surgery. The overall survival rates were 85% from a second ACL revision and 68% from all reoperations of the index knee. Considering only the successful procedures (61 patients), at final follow-up, the mean values for the KOOS subscales were 84 ± 15.5 for Pain, 88.1 ± 13.6 for Symptoms, 93 ± 11.6 for ADL, 75 ± 24.5 for Sport, and 71 ± 19.6 for Qol. Twenty-nine (48%) patients performed sports activity at the same level as before ACLR failure.

CONCLUSIONS

Double-bundle ACL revision with fresh-frozen Achilles allograft yields satisfactory results at long-term follow-up, with an 85% survival rate from a second ACL revision at mean 10 years' follow-up and good patient-reported clinical scores.

LEVEL OF EVIDENCE

Level IV.

Association of Elevated Posterior Tibial Slope With Revision Anterior Cruciate Ligament Graft Failure in a Matched Cohort Analysis

BACKGROUND

Elevated posterior tibial slope (PTS) has been identified as an important risk factor in anterior cruciate ligament (ACL) injuries and ACL graft failures. The cutoff value to recommend treatment with slope-reducing osteotomy remains unclear and is based on expert opinion and small case series.

PURPOSE

(1) To determine whether there is a difference in PTS shown on lateral knee radiographs and magnetic resonance imaging (MRI) scans in a group of patients who experienced revision ACL graft failure versus a control group of patients who underwent successful revision ACL reconstruction, (2) to identify cutoff values of PTS measurements that predict risk of revision ACL graft failure, and (3) to examine whether there is a correlation between radiographic and MRI measurements of PTS.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 38 patients who experienced revision ACL graft failure were identified from a revision ACL database. These patients were matched 1:1 by age, sex, and graft type to a group of 38 control patients who underwent revision ACL reconstruction with no evidence of graft failure at a minimum 2 years of follow-up. Medial and lateral PTS were measured by lateral knee radiographs and MRI scans of the affected limb. Demographics, surgical characteristics, and PTS were compared between the groups. The optimal cutoff values of medial and lateral PTS per radiographs and MRI scans for predicting increased risk of revision ACL graft failure were determined by receiver operating characteristic curves. Conditional multivariable logistic regression was used to assess the relative contribution of PTS cutoff values as a predictor of revision graft failure.

RESULTS

The mean PTS values in the failure group were significantly higher than those in the control group on radiographs (medial, 13.2°± 2.9° vs 10.3°± 2.9°; P < .001; lateral, 12.9°± 3.0° vs 9.8°± 2.8°; P < .001) and MRI scans (medial, 7.2°± 3.1° vs 4.8°± 2.9°; P < .001; lateral, 8.4 ± 3.1° vs 5.9 ± 3.0°; P < .001). A radiographic medial PTS ≥14° had the highest increased risk of revision ACL graft failure with sensitivity equal to 50% and specificity to 92.1% (odds ratio, 18.71; 95% CI, 2.0-174.9; P = .01).

CONCLUSION

Elevated PTS was a significant risk factor for revision ACL graft failure. Patients with radiographic medial PTS ≥14° had 18.7-times increased risk of revision ACL failure.

Lateral Extra-Articular Tenodesis Staple Risks Penetration of Anterior Cruciate Ligament Reconstruction Tunnel

Purpose

To identify the risk of anterior cruciate ligament (ACL) femoral tunnel penetration with the use of a staple for lateral extra-articular tenodesis (LET) graft fixation and to determine whether this varied between 2 different techniques for ACL femoral tunnel drilling.

Methods

Twenty paired, fresh-frozen, cadaver knees underwent ACL reconstruction with a LET. Left and right knees were randomized to ACL reconstruction with femoral tunnel creation by use of either a rigid guide pin and reamer through the accessory anteromedial portal or by the use of a flexible guide pin and reamer through the anteromedial portal. Immediately after tunnel creation, the LET was performed and fixated with a small Richard's staple. Fluoroscopy was used to obtain a lateral view of the knee to determine staple position, and visualization of the ACL femoral tunnel was performed with the arthroscope to investigate penetration of the staple into the femoral tunnel. The Fisher exact test was conducted to determine whether there was any difference in tunnel penetration between tunnel creation techniques.

Results

The staple was noted to penetrate the ACL femoral tunnel in 8 of 20 (40%) extremities. When stratified by tunnel creation technique, the Richards staple violated 5 of 10 (50%) of the tunnels made via the rigid reaming technique compared with 3 of 10 (30%) of those created with a flexible guide pin and reamer (P = .65).

Conclusions

A high incidence of femoral tunnel violation is seen with lateral extra-articular tenodesis staple fixation.

Level of Evidence

Level IV, controlled laboratory study.

Clinical Relevance

The risk of penetrating the ACL femoral tunnel with a staple for LET graft fixation is not well understood. Yet, the integrity of the femoral tunnel is important for the success of ACL reconstruction. Surgeons can use the information in this study to consider adjustments to operative technique, sequence, or fixation devices used when performing ACL reconstruction with concomitant LET to avoid the potential for disruption of ACL graft fixation.

Return to duty in military personnel after ACL reconstruction: STG versus ST4 double adjustable-loop device

INTRODUCTION

ACL ligamentoplasty with a quadruple semitindosus graft (ST4) and double adjustable endobutton (ST4E) allow the preservation of the gracilis, which should allow more rapid recovery of soldiers following ACL reconstruction. However, the literature does not report any superiority of this technique over others in terms of return to duty and sport.

HYPOTHESIS

The ST4E system allows a return to military duty at least equivalent to the semitendinosus and gracilis graft (STG) with screw fixation.

MATERIAL AND METHOD

A total of 133 soldiers operated on for ACL were included, 64 by the STG technique and 69 by ST4E, with an average follow-up of 4 years. The return to duty was assessed, with recovery of skills between the first and second postoperative year, as well as the medico-administrative status at the last follow-up, muscle recovery through isokinetic tests, the sports level before/after surgery, and the failure rate.

RESULTS

No difference was found in the return to the soldier's previous post between the STG (64%) and the ST4E (64%) (p=0.97). No difference was found for the medico-administrative status at the last follow-up, but the short-term muscle recovery, the return to sport, and the failure rate were in favor of the ST4E group.

DISCUSSION

The ST4E, adjustable double endobutton system, is comparable to the STG technique in terms of return to military duty. On the other hand, it offers faster muscle recovery with better sports results and fewer patients on prolonged sick leave (PSL). This study demonstrated that two-thirds of soldiers operated on for anterior cruciate ligamentoplasty regained their initial aptitude regardless of the technique used, which influences the army's operational capacity and on disability pension requests after service.

LEVEL OF EVIDENCE

III, single center retrospective comparative study.

Range of Motion, Strength, and Function After ACL Reconstruction Using a Contralateral Patellar Tendon Graft

BACKGROUND

Regaining preinjury levels of activity and progressing rehabilitation factors after anterior cruciate ligament (ACL) reconstruction have shown mixed results.

PURPOSE

To evaluate the timing and rate of return for knee range of motion (ROM), stability, strength, and subjective scores after ACL reconstruction with contralateral patellar tendon graft (PTG).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Included were 2148 patients (1238 male patients, 910 female patients) who underwent primary ACL reconstruction with a contralateral PTG between 1995 and 2017 and had complete objective data through 3 months of follow-up. All patients participated in a rehabilitation program specific to goals for each knee. Patients were evaluated objectively with goniometric measurement of ROM, isokinetic quadriceps strength testing, and laxity with a KT-2000 arthrometer. Subjective data were collected at 2 and 5 years.

RESULTS

Normal extension on the reconstructed knee was attained for 95% of patients at 1 week postoperatively; normal flexion on the reconstructed knee was reached by 77% of patients by 3 months. At 3 months postoperatively, mean limb symmetry index strength was 104%, and the strength on the ACL-reconstructed and graft-donor knees was 87% and 86% of their respective preoperative strength. Mean manual maximum side-to-side difference in laxity was 2.0 mm at 1 month. Most patients (90%) returned to level 8 sports or higher and did so at an average of 5.7 months. Mean International Knee Documentation Committee scores for the ACL-reconstructed and graft-donor knees were 89 and 91 at 2 years (n = 1015 patients) and 84 and 90 at 5 years (n = 1275 patients), respectively. Mean Cincinnati Knee Rating Scale scores for the ACL-reconstructed and graft-donor knees were 92 and 96 at 2 years (n = 1184) and 88 and 94 at 5 years (n = 1236), respectively.

CONCLUSION

For patients who underwent ACL reconstruction with a contralateral PTG, postoperative ROM and strength were restored quickly by splitting the rehabilitation into different goals between the two knees. Using a contralateral PTG, this structured rehabilitation plan can lead to a relatively quick return to sport and good subjective long-term outcomes.

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.

Differentiation in Posterior Tibial Slope by Sex, Age, and Race: A Cadaveric Study Utilizing 3-Dimensional Computerized Tomography

BACKGROUND

Posterior tibial slope (PTS) has recently gained increased attention for its possible role in anterior cruciate ligament and posterior cruciate ligament injury. The possible differences among age, sex, and ethnicity in PTS have not yet been reported.

PURPOSE

To describe demographic variances of proximal tibial anatomy and to detect differences in regard to ethnicity, sex, and age.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

In total, 250 cadaveric specimens with full-body computerized tomography scans from the New Mexico Descendant Imaging Database were randomly selected (inclusion/exclusion criteria: older than 18 years, complete imaging of the knee without previous surgery or arthroplasty) and reviewed by 3 independent observers measuring medial posterior tibial slope (MPTS), lateral posterior tibial slope (LPTS), and global posterior tibial slope (PTS), which was calculated as the mean of the MPTS and LPTS. Individuals were evenly divided among male and female and ethnicities/races: African American/Black, Asian American, Hispanic, Native American, and White. Intraclass correlation coefficient was calculated for interobserver reliability and analysis of variance statistical testing to determine statistical significance between groups. Fisher exact test was also used to understand PTS differences among ethnicities when looking at clinically significant values for potential ligamentous injury.

RESULTS

Measurements were obtained from 250 specimens with a mean age of 49.4 years (range, 19 to 103 years). The mean PTS was 8.92° (range, -9.4° to 14.95°). Asian Americans had a 1.7° greater mean MPTS than Whites (P = .016), and African Americans/Blacks had a 1.6° greater mean PTS than Whites (P = .022). No difference in mean PTS was seen between age and sex. When looking at clinically significant PTS, 61 (24.4%) individuals had tibial slopes <6° or >12°, 32 (12.8%) and 29 (11.6%), respectively. Statistically significant differences were seen among ethnicities with PTS <6° (P = .017) but not with PTS >12° (P = .106). No sex-based differences were seen in the percentage of specimens with a PTS of >12° or <6°.

CONCLUSION

Among ethnicities, African Americans/Blacks and Asian Americans have increased PTS in comparison with Whites. Nearly 25% of individuals have clinically significant slopes of <6° or >12°, with no difference in tibial slope among sex or age groups.

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.

Influence of hamstring tendon and bone-patellar tendon-bone autografts on worsened patient reported outcome measurements in revision anterior cruciate ligament reconstruction: Comparing outcomes between primary and revision reconstructions

Background

This study aimed to compare the clinical outcomes and patient reported outcome measurement scales (PROMs) between hamstring tendon (HT) or bone-patellar tendon-bone (BTB) grafts in each primary and revision anterior cruciate ligament (ACL) reconstruction. Additionally, the clinical outcomes and PROMs between primary and revision surgeries were compared.

Methods

A total of 150 patients (109 primary and 41 revision ACL reconstructions) were enrolled and followed up for an average of 3.9 years (2 years minimum). Knee injury and osteoarthritis outcome scores (KOOS) were examined as PROMs. Side-to-side differences of anterior knee laxity were assessed using KT-1000 and were recorded at the final follow-up. After categorizing patients into HT and BTB reconstruction groups, regression analysis was performed to determine the relationship between revision surgery and changes in KOOS.

Results

In patients who underwent primary surgery, there was no significant difference in side-to-side differences of anterior laxity and KOOS between HT and BTB grafts. In those who underwent revision surgery, BTB grafts had a higher KOOS for activities of daily living (ADL) than HT grafts (p = 0.032). Comparing primary and revision surgeries, postoperative side-to-side differences of anterior laxity in the revision group were significantly larger than those in the primary group (p = 0.001). The KOOS for sports after overall revision reconstruction was significantly lower than that after primary reconstruction (p = 0.026). Comparing the KOOS after dividing all patients into HT and BTB reconstruction groups, in the HT reconstruction group, postoperative KOOS results were not different in any subscale from BTB grafts. In contrast, the KOOS for sports (p = 0.008) and QOL (p = 0.039) were significantly lower in revision surgery than in primary surgery. Furthermore, regression analysis including multiple confounders in the HT reconstruction group showed revision surgery using HT graft was correlated with worsened KOOS for symptoms (p = 0.012) and sports (p = 0.010). Revision surgery using BTB graft was not correlated with decreased KOOS.

Conclusions

There were no differences between the clinical outcome and KOOS in primary and revision surgery, except for ADL scores following revision ACL reconstruction using BTB graft. Side-to-side difference of anterior laxity and KOOS for sports following revision ACL reconstruction were inferior to those following primary ACL reconstruction.

Furthermore, revision ACL reconstruction using HT grafts were correlated with low scores in KOOS for symptoms and sports, while there was no difference of anterior laxity between BTB and HT grafts in revision surgery.

No Differences In Clinical Outcomes Between Rectangular and Round Tunnel Techniques For Anterior Crucial Ligament Reconstruction

PURPOSE

To compare the clinical outcomes between conventional round tunnel and rectangular tunnel in anatomic anterior cruciate ligament (ACL) reconstruction.

METHODS

This was a retrospective comparative cohort study between March 2015 and September 2018. The primary ACL reconstructions using anteromedial portal technique with minimum of 2 years follow-up were enrolled for this study. The exclusion criteria were patients with revision ACL reconstruction, high tibial osteotomy, multiligament injuries, and associated fractures around the knee. Outcome measures included the subjective International Knee Documentation Committee score, Tegner activity score, knee laxity testing, and measurement of the centers of the femoral and tibial tunnels on postoperative computed tomography (CT) images.

RESULTS

Forty-seven patients with ACL reconstruction with rectangular tunnel (group 1) and 108 patients with ACL reconstructions with conventional rounded tunnel (group 2) were included consecutively. There were no significant differences between groups in terms of clinical scores or knee laxity, as well as femoral and tibial tunnel positions on CT. One patient in group 2 had ACL failure because of trauma and was treated with revision surgery. Two patients had incomplete tibial fracture, but they healed spontaneously and showed no residual laxity at final follow-up. The intraobserver and interobserver reliability for the radiological measurements ranged from 0.78 to 0.86.

CONCLUSIONS

There were no differences in radiological and clinical results between rectangular tunnel group and conventional round tunnel group for arthroscopic ACL reconstruction. ACL reconstruction with a rectangular tunnel could be considered as a reliable technique, but care should be taken during tunnel establishment because of risk of fractures and malposition of rectangular tunnel.

Sufficient MRI graft structural integrity at 9 months after anterior cruciate ligament reconstruction with hamstring tendon autograft

PURPOSE

To assess the MRI-measured structural integrity of hamstring autograft at 9 months after anterior cruciate ligament reconstruction (ACLR) surgery.

METHODS

A prospective cohort study was conducted including 34 patients (mean age 36.8 ± 11.8 years; 73.5% males) who underwent ACLR with hamstring autograft. In addition, 36 patients (mean age 39.2 ± 10.5 years; 69.4% males) without any ACL injury were also reviewed and served as control group. The primary outcome used for examining graft maturity at 9 months after ACLR was the MRI-based signal-to-noise quotient (SNQ) of reconstructed ACL. SNQ values were stratified into 3 different categories: excellent: < 0.1; good: ≥ 0.1 and ≤ 0.19; fair: ≥ 0.2. The KT-1000 knee arthrometer was used to measure the side-to-side difference in the anterior tibial translation between the ACLR knee and the contralateral healthy knee in the ACLR group.

RESULTS

Reconstructed ACLs were found with a mean SNQ of 0.078 ± 0.061, while almost all ACL-reconstructed patients (97%; 33 out of 34) were found with excellent or good SNQ values (< 0.019). The mean KT-1000 in the ACLR group was 0.071 mm ± 0.926 mm, while there were no patients in the ACLR cohort with a KT-1000 value > 3 mm. The mean 9-months MRI-based SNQ of ACLR group was significantly higher compared to the mean MRI-based SNQ of the control group (p < 0.001). Multiple regression analysis showed no correlation between SNQ and age, gender, time from injury to ACLR, graft size, or simultaneous treatment of additional intra-articular knee lesions.

CONCLUSIONS

In this cohort of 34 ACL-reconstructed patients, 97% of hamstring tendon autografts demonstrated excellent/good MRI signal intensity and excellent functional results (KT-1000 < 3 mm) at 9 months after surgery. Based on this finding, it is suggested that return to sports after ACLR with hamstring autograft can be considered safe at 9 months post surgery. Furthermore, while structural integrity of the graft has been achieved at this time point, statistical differences found in SNQ values of ACL-reconstructed patients compared to ACLs of healthy individuals highlight the continuing process of graft maturation and remodelling.

LEVEL OF EVIDENCE

Level III.

Therapeutic Patient Education after Anterior Cruciate Ligament Reconstruction: Evaluation of the Knowledge and Certitudes with a Self-Report Questionnaire

Therapeutic education aims to help patients acquire skills and knowledge, and to improve psychosocial aspects to manage chronic disease. After anterior cruciate ligament reconstruction (ACLR), only 35 to 60% of the patients are able to go back to their previous sport. Return to sport depends on the motivation of the patient. No therapeutic education has already been proposed. We aimed to evaluate the effect of therapeutic education sessions on knowledge improvement during inpatient rehabilitation after ACLR, compared to patients operated with the same surgical technic, but who had no therapeutic education because of outpatient rehabilitation. Sessions were performed by a multidisciplinary team. The evaluation of the knowledge was performed with a true or false 12-items self-report questionnaire. Fifty-four patients were studied and compared to 54 patients with no therapeutic education. The educated and the non-educated groups were comparable. The number of correct answers increased from 73% before therapeutic education to 95% at the end of the hospitalization (p < 0.001). This improvement persisted over time with 91.5% of correct answers at four months (p = 0.94). The non-educated group had 70% of correct answers. This was significantly lower than the results obtained from the educated group at four months (p < 0.001). It was comparable to the result obtained before therapeutic education (p = 0.91). Therapeutic patient education performed during hospitalization for rehabilitation enables patients to have a better knowledge of the stages from rehabilitation to return to sport and the risks of complication after ACLR.

Femoral intercondylar notch: Accuracy of a novel MRI measurement protocol

OBJECTIVE

The most common mechanical complication following an anterior cruciate ligament (ACL) reconstruction is joint stiffness, due in part to cyclops syndrome. A narrow intercondylar notch is an anatomical risk factor. A reliable preoperative notch measurement would help anticipate proper graft size, or plan a notchplasty during the ligament reconstruction, if necessary. No study has yet assessed the accuracy of the methods used to measure notch size.

HYPOTHESIS

The novel measurement protocol proposed in this study would be more reproducible than the reference technique.

METHODS

A total of 20 preoperative knee MRIs performed during the assessment of an ACL rupture were randomly selected. The notch size was measured using 2 methods: traditional (ratio of the notch and metaphyseal widths measured on a line drawn through the popliteal groove) and novel. The latter was measured using the same ratio but took into account the notch width in its proximal third, according to a coronal slice that passes through the ACL tibial attachment. Three orthopedic surgeons with different levels of experience (senior surgeon, junior surgeon and surgical resident) performed these measurement protocols twice on anonymized MRI scans, 10days apart. Spearman's rank correlation coefficient was used to assess the intraobserver correlations and a concordance index was used to assess the interobserver correlations. The influence of the second MRI reading was analyzed with a bootstrap test.

RESULTS

The mean intraobserver reliability was 0.73 for the reference method and 0.83 for the proposed method. The values of the bootstrap tests were higher for the proposed method (0.45 vs. 0.45 and 0.70; p<05 for interobserver; 0.49 vs. 0.69 and 0.62; p<05 for intraobserver).

CONCLUSION

The proposed measurement protocol showed a higher reproducibility in assessing notch size than the traditional method. This technique therefore provides a reliable assessment of the intercondylar notch width.

LEVEL OF EVIDENCE

IV; retrospective study.

Meniscal Tears, Posterolateral and Posteromedial Corner Injuries, Increased Coronal Plane, and Increased Sagittal Plane Tibial Slope All Influence Anterior Cruciate Ligament-Related Knee Kinematics and Increase Forces on the Native and Reconstructed Anterior Cruciate Ligament: A Systematic Review of Cadaveric Studies

PURPOSE

To obtain a comprehensive list of pathologies that cause increased anterior cruciate ligament (ACL) forces and pathologic knee kinematics to evaluate for in both primary and revision ACL reconstruction to decrease the risk of subsequent graft overload.

METHODS

An electronic search was performed in the Embase and MEDLINE databases for the period between January 1, 1990, and December 10, 2020. All articles investigating medial and lateral meniscal injury, (postero)lateral corner injury, (postero)medial corner/medial collateral ligament injury, valgus alignment, varus alignment, and tibial slope in relation to ACL (graft) force and knee kinematics were included.

RESULTS

Data of 43 studies were included. The studies reported that high-volume medial and lateral meniscectomies, peripheral meniscus tears, medial meniscus ramp tears, lateral meniscus root tears, posterolateral corner injuries, medial collateral ligament tears, increased tibial slope, and valgus and varus alignment were reported to have a significant impact on ACL (graft) force and related knee kinematics.

CONCLUSIONS

This systematic review on biomechanical cadaver studies provides a rationale to systematically identify and treat pathologies in ACL-injured knees, because when undiagnosed or left untreated, these specific concomitant pathologies could lead to ACL graft overload in both primary and revision ACL-reconstructed knees.

CLINICAL RELEVANCE

it is necessary that orthopaedic surgeons who treat ACL-injured knees understand the surgically relevant biomechanical consequences of additional pathologies and use this knowledge to optimize treatment in ACL-injured patients.

Low annual hospital volume of anterior cruciate ligament reconstruction is not associated with higher revision rates

PURPOSE

Surgery performed in low-volume centres has been associated with longer operating time, longer hospital stays, lower functional outcomes, and higher rates of revision surgery, complications and mortality. This has been reported consistently in the arthroplasty literature, but there is a paucity of data regarding the relationship between surgical volume and outcome following anterior cruciate ligament (ACL) reconstruction. The purpose was to compare ACL reconstruction failure rates between hospitals performing different annual surgical volumes.

METHODS

All patients from the Norwegian Knee Ligament Register having primary autograft ACL reconstruction between 2004 and 2016 were included. Hospital volume was divided into quintiles based on the number of ACL reconstructions performed annually, defined arbitrarily as: 1-12 (V1), 13-24 (V2), 25-49 (V3), 50-99 (V4) and ≥ 100 (V5) annual procedures. Kaplan-Meier estimated survival curves and survival percentages were calculated with revision ACL reconstruction as the end point. Secondary outcome measures included (1) mean change in Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) and Sport subsections from pre-operative to 5-year follow-up and (2) subjective failure defined as KOOS QoL < 44.

RESULTS

Twenty thousand eight hundred and fifty patients met the inclusion criteria and 1195 (5.7%) underwent subsequent revision ACL reconstruction over the study period. Revision rates were lower in the lower volume hospitals compared with the higher volume hospitals (p < 0.001). There was no clinically significant difference in improvement between pre-operative and 5-year follow-up KOOS scores between hospital volume categories, but a higher proportion of patients having surgery at lower volume hospitals reported a subjective failure. Patients in the lower volume categories (V1-3) were more often male and older compared to the higher volume hospitals (V4-5). Concomitant meniscal injuries and participation in pivoting sports were most common in V5 compared with V1 (p < 0.001). Median operative time decreased as hospital volume increased, ranging from 90 min at V1 hospitals to 56 min at V5 hospitals (p < 0.001).

CONCLUSION

Patients having ACL reconstruction at lower volume hospitals had a lower rate of subsequent revision surgery relative to higher volume hospitals. However, complications occurred more frequently, operative duration was longer, and the number of patients reporting a subjective failure of ACL reconstruction was highest at these lower volume hospitals.

LEVEL OF EVIDENCE

Level III.

Revision ACL reconstruction has higher incidence of 30-day hospital readmission, reoperation, and surgical complications relative to primary procedures

PURPOSE

Although there has been substantial improvement in ACL reconstructive surgery, graft failure remains a devastating complication for some patients. Revision procedures are inherently more complex and technically challenging. The purpose of this study is to determine the incidence of short-term complications after these procedures and to compare trends in operative length, relative valuation, and reimbursement after primary versus revision ACL reconstruction.

METHODS

Primary and revision arthroscopic ACL reconstruction cases were identified on the American College of Surgeons' NSQIP database using Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes between January 1, 2012 and December 31, 2017. Demographics, patient variables, and surgical variables were compared between primary and revision groups using Chi-squared tests. Logistic regression was used to identify independent risk factors for revision ACL reconstruction. Various 30-day outcome measures were compared between the primary and revision ACL reconstruction groups. Various measures of valuation-including total relative value units (RVU) and reimbursement per minute-were calculated and compared between the two groups.

RESULTS

A total of 8292 patients-8135 primary and 157 revision procedures-were included in the final cohort. Higher ASA scores were associated with revision ACL reconstructions. Patients undergoing revision procedures were less likely to have an ASA score of 1 (p < 0.001) and more likely to have an ASA score of 2 (p = 0.004) or 3 (p = 0.020). Revision ACL reconstruction was associated with higher rates of poor 30-day outcome measures, including unplanned readmission (p = 0.029), reoperation (p = 0.012), return to the OR (p = 0.012), and surgical complications (p = 0.021). The total RVUs and reimbursement for revision procedures were significantly greater than those for primary procedures (p < 0.001). However, when accounting for operative time, the RVU/minute and reimbursement/minute were similar between the two groups (n.s.).

CONCLUSIONS

Relative to primary ACL reconstruction, revision ACL procedures are associated with worse short-term outcomes-including unplanned readmission, reoperation, return to the OR, and surgical complications. A greater ASA score was independently predictive of revision ACL surgery. The current RVU system undervalues revision ACL procedures, considering the increased operative time and complexity of such procedures.

LEVEL OF EVIDENCE

Level III.

Psychological, physical and social factors influence decision to return to sport after revision ACL reconstruction with BPTB graft

PURPOSE

There is limited evidence in literature regarding the patient-reported factors that influence their return to sport (RTS) in revision anterior cruciate ligament reconstruction (ACLR). The medium-term results of a prospective consecutive cohort of patients undergoing single- and two-stage revision ACLR with bone patellar tendon bone graft (BPTB) and patient-reported factors that influence their decision to return to sport are presented in this study.

METHODS

Seventy-two patients were included in this prospective study. Single- or two-stage revision with BPTB graft was performed based on pre-operative planning. Iliac crest bone graft was used. Pre-operative and follow-up Lysholm and Tegner activity scores and RTS, level of sport and patient-reported factors affecting RTS were recorded. The mean follow-up was 9 years (SD 2.7 years).

RESULTS

Single-stage revision ACLR was performed in 61 patients. In 11 patients (15%), revision ACLR was performed in two stages. There was a significant improvement in Lysholm score from mean 51.1 to 86.7 (p < 0.001). The incidence of re-rupture in this cohort was 0%. The median Tegner score was 6 (range 2-9). Twenty-five patients (34.7%) did not return to any sport at final follow-up. Twenty-nine (40.2%) patients returned to their pre-injury level of sport. Fear of reinjury (79%, p < 0.001) and persistent knee symptoms (35.8%, p = 0.03) were the most common factors limiting RTS in non-returners.

CONCLUSION

Psychological and social factors may have an influence on RTS in addition to physical factors.

LEVEL OF EVIDENCE

Level III.

High variability and lack of standardization in the evaluation of return to sport after ACL reconstruction: a systematic review

PURPOSE

Return to sport (RTS) after ACL reconstruction (ACLR) has been recognized as an important outcome, which is associated with success of the surgery. This study aimed to assess the methods used to determine return to sport after ACLR in the published literature, report on variability of methods and evaluate their strength in establishing accurate RTS data.

METHODS

Electronic databases (PubMed, Cochrane Library and Embase) were searched via a defined search strategy with no limits, to identify relevant studies from January 2008 to December 2020 for inclusion in the review. Defined eligibility criteria included studies specifically measuring and reporting on return to sport after ACLR with a clear methodology. Each included study was assessed for the definition of successful RTS, successful return to pre-injury level of sport and for methods used to determine RTS.

RESULTS

One hundred and seventy-one studies were included. Of the included studies, six studies (4%) were level of evidence 1 and seventy-two studies (42%) were level of evidence 4. Forty-one studies (24%) reported on return to a specific sport and 130 studies (76%) reported on return to multiple sports or general sport. Sixteen studies (9%) reported on RTS in the pediatric population, 36 (21%) in the adult population and 119 (70%) reported on a mixed-aged population. The most commonly used definition of successful RTS was return to the same sport (44 of 125 studies, 35%). The most common method used to determine RTS was a non-validated study-specific questionnaire (73 studies, 43%), which was administered in various ways to the patients. Time of RTS assessment was variable and ranged between 6 months and 27 years post-surgery.

CONCLUSION

This review demonstrates high variability in defining, evaluating and reporting RTS following ACLR. The findings of this study reveal low reliability and unproven validity of methods used to evaluate RTS and highlight the challenges in interpreting and using RTS data reported in literature.

LEVEL OF EVIDENCE

IV.