Anterior cruciate ligament reconstruction autograft choice: bone-tendon-bone versus hamstring: does it really matter? A systematic review

Hyperbaric oxygen therapy enhances graft healing and mechanical properties after anterior cruciate ligament reconstruction: An experimental study in rabbits

Hyperbaric oxygen therapy (HBOT) has proven successful in wound healing. However, its potential effects on anterior cruciate ligament (ACL) injuries remain uncertain. This study aimed to investigate the impact of HBOT on graft healing following ACL reconstruction in rabbits. Male New Zealand rabbits underwent ACL reconstruction and were randomly divided into two groups: the HBOT group and the ambient air group. The HBOT group received 100% oxygen at 2.5 atmospheres absolute for 2 h daily for 5 consecutive days, starting from the first day after surgery. The ambient air group was maintained in normal room air throughout the entire period. After 12 weeks following the surgery, animals were euthanized, and their knees were harvested for analysis. The HBOT group demonstrated superior graft maturation and integration in comparison to the ambient air group, as evidenced by lower graft signal intensity on magnetic resonance imaging, decreased femoral and tibial tunnel size, and higher bone mineral density values on high-resolution peripheral quantitative computed tomography scans. Additionally, biomechanical testing indicated that the HBOT group had greater load to failure and stiffness values than the ambient air group. In conclusion, the adjuvant use of HBOT improved ACL graft maturation and integration, reduced tunnel widening, and enhanced the biomechanical properties of the graft. These results may provide important insights into the potential clinical application of HBOT as a therapeutic intervention to enhance graft healing after ACL reconstruction, paving the way for further research in this area.

How Does Physical and Psychological Recovery Vary Among Competitive and Recreational Athletes After Anterior Cruciate Ligament Reconstruction?

BACKGROUND

The recovery and rehabilitation journey after anterior cruciate ligament reconstruction (ACLR) surgery can be different for competitive and recreational athletes as their motivation and goals toward sports are different.

HYPOTHESIS

Competitive athletes would present with better patient-reported outcomes and higher muscle strength compared with recreational athletes postsurgery. Second, competitive athletes would recover better (patient-reported outcome [PRO] measures and muscle strength) compared with recreational athletes at later stages.

STUDY DESIGN

Cross-sectional laboratory-based study.

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 245 patients with unilateral ACLR were categorized as competitive or recreational athletes and grouped into early (4-6.9 months) or late (7-10 months) stages of recovery. PRO were collected for psychological response (Tampa Scale Kinesiophobia; Anterior Cruciate Ligament-Return to Sport after Injury), perceived knee function (International Knee Documentation Committee subjective form [IKDC]), and quality of life (Knee injury and Osteoarthritis Outcome Score; Veteran Rand-12). Isokinetic, concentric knee extension strength was measured bilaterally with a multimodal dynamometer (System 4, Biodex Medical Systems) at a speed of 90° and 180°/s.

RESULTS

Competitive athletes had significantly higher scores for IKDC (P = 0.03), and quadriceps peak torque at 90°/s (P = 0.01) and 180°/s (P < 0.01) compared with recreational athletes. Competitive athletes had higher quadriceps strength at 90°/s (P < 0.01) and 180°/s (P = 0.02) in the late group. Recreational athletes displayed higher sports participation in the late group.

CONCLUSION

Outcomes of ACLR may differ based on preinjury athletic level. Whereas competitive athletes had higher knee and muscle function than recreational athletes, psychological measures were not different among groups.

CLINICAL RELEVANCE

There is a need for more individualized care for patients with ACLR since there is variability among patient goals postsurgery. This information might help set realistic expectations for competitive and recreational athletes after surgery.

Difference of Knee Strength Recovery Between Revision and Primary ACL Reconstruction

Different grafting procedures are available to restore knee stability after revision anterior cruciate ligament (ACL) reconstruction. We compared knee strength recovery between ACL revision surgery and primary reconstruction. One hundred and ten patients with ACL revision surgery were matched with 110 patients with primary reconstruction based on the graft procedure. The isokinetic knee strength had been assessed for the first 9 months post-surgery. Knee laxity, function, and activity score were also evaluated. Limb symmetry index for knee extensor and flexor strength was not different at 4-, 6- and 9-months post-surgery between revision surgery and primary reconstruction. These results depended on ipsilateral or contralateral graft choice. Ipsilateral hamstring tendon (HT) and contralateral bone-patellar-tendon-bone (BPTB) graft procedures were similar for a revision of a BPTB graft failure. Contralateral HT procedure was better than ipsilateral BPTB procedure for a revision of a HT graft failure. The early recovery of isokinetic knee strength after ACL revision surgery regardless of the HT or BPTB procedures, was similar to the recovery after primary ACL reconstruction with the same graft technique. These results apparently depended on a temporary quadriceps arthrogenic muscle inhibition and on a persistent donor site morbidity, concerning the new and the previous grafts, respectively.

Editorial Commentary: Promising Short-Term Results of Adolescent Transphyseal Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft Warrant Long-Term Follow-Up Study

Several graft choices have been described for surgeons performing anterior cruciate ligament reconstruction. Bone-patellar tendon-bone autograft has been referred to as the gold standard with which other grafts are compared. Hamstring autograft has been widely used when a soft-tissue graft is desired, such as when physes are open with significant growth remaining, but with greater revision rate than bone-patella tendon-bone in young athletes. Allograft tissue is discouraged in younger patients due to increased re-rupture rate. More recently, quadriceps autograft has been described as another soft tissue graft. Quadriceps tendon grafts do show promise as a soft-tissue graft alternative with a potential drawback of decreased knee extension strength, although longer-term follow-up studies are necessary to evaluate its use in the pediatric population.

Outcomes of Primary Anterior Cruciate Ligament (ACL) Repair for Proximal Tears: A Systematic Review and Meta-Analysis

The purpose of this study is to compare failure rates among different techniques of primary anterior cruciate ligament (ACL) repair for the treatment of proximal ACL ruptures. Meta-analysis and systematic review were completed, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Studies from Embase, Cochrane, and PubMed published between June 2011 and June 2022 reporting outcomes of primary ACL repair on proximal tears with a minimum two-year follow-up were included. Primary ACL repair was divided into dynamic, static, and non-augmented repair. The primary outcome was failure rates, and the secondary outcomes included patient-reported outcomes (PROs) and anterior tibial stability (ATT). Eighteen studies on primary ACL repair were included, with a total of 614 patients (ages ranging from 6 to 65, 60% male). Only two studies were level 1 randomized controlled clinical trials. The static repair had a failure rate of 33 out of 261 (12.6%), non-augmented was 17 out of 179 (9.4%), and dynamic repair was 31 out of 174 (17.8%); no statistically significant difference was found comparing the failure rates (p = 0.090). PROs using the International Knee Documentation Committee (IKDC) and Lysholm scores had weighted averages of 91.7 (95% confidence interval (CI): 89.6-93.8) and 94.7 (95% CI: 92.7-96.7), respectively. ATT had a weighted average of 1.668 mm (95% CI: 1.002-2.334). The primary findings of this paper include a 12.6% combined failure rate for primary proximal ACL repair with no significant difference in failure rate or PROs when accounting for the methodology of repair at a minimum two-year follow-up. It is important to note the lack of high-quality randomized controlled trials, the heterogeneity of included studies, and the lack of long-term data. Despite these limitations, the findings of the current analysis suggest that primary repair may be a useful treatment option for indicated candidates with proximal ACL ruptures. Further long-term and higher-quality comparative studies on ACL reconstruction are warranted.

Following Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Autograft, the Incidence of Anterior Knee Pain Ranges From 5.4% to 48.4% and the Incidence of Kneeling Pain Ranges From 4.0% to 75.6%: A Systematic Review of Level I Studies

Purpose

To (1) perform a systematic review of level I randomized controlled trials (RCTs) detailing the incidence of anterior knee pain and kneeling pain following anterior cruciate ligament reconstruction (ACLR) with bone-patellar tendon-bone (BPTB) autograft and (2) investigate the effect of bone grafting the patellar harvest site on anterior knee and kneeling pain.

Methods

A systematic review of level I studies from 1980 to 2023 was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome evaluated was the presence of donor site morbidity in the form of anterior knee pain or kneeling pain. A secondary subanalysis was performed to assess for differences in the incidence of postoperative pain between patient groups undergoing ACLR with BPTB receiving harvest site bone grafting and those in whom the defect was left untreated.

Results

Following full-text review, 15 studies reporting on a total of 696 patients met final inclusion criteria. Patients were followed for an average of 4.78 years (range, 2.0-15.3), and the mean age ranged from 21.7 to 38 years old. The incidence of anterior knee pain, calculated from 354 patients across 10 studies, ranged from 5.4% to 48.4%. The incidence of postoperative pain with kneeling was determined to range from 4.0% to 75.6% in 490 patients from 9 studies. Patients treated with bone grafting of the BPTB harvest site had no significant difference in incidence of any knee pain compared with those who were not grafted, with incidences of 43.3% and 40.2%, respectively.

Conclusions

Based on the current level I RCT data, the incidences of anterior knee pain and kneeling pain following ACLR with BPTB autograft range from 5.4% to 48.4% and 4.0% to 75.6%, respectively.

Level of Evidence

Level I, systematic review of RCTs.

Analysis of Changing Practice Trends in Anterior Cruciate Ligament Reconstruction: A Multicenter, Single-Institution Database Analysis

PURPOSE

To identify trends in anterior cruciate ligament reconstruction (ACLR), including graft choice, femoral tunnel drilling techniques, and augmentation techniques, and to assess how various surgeon factors impact these trends.

METHODS

A retrospective review of primary ACLRs performed between 2014 and 2022 was completed using a multicenter institutional database. Patient demographic characteristics, graft type, femoral drilling technique, use of extra-articular tenodesis, and use of suture augmentation were recorded from the medical record. Surgeon fellowship training (sports trained vs non-sports trained), experience (high [minimum of 15 years in practice] vs low), and volume (high [minimum of 15 ACLRs/year] vs low) were used to stratify technique utilization. The z test for proportions was used to compare categorical variables. Pearson correlation analyses identified trends and assessed statistical significance, defined as P < .05.

RESULTS

Our cohort consisted of 2,032 ACLRs performed in 2,006 patients. The average patient age was 28.3 ± 11.6 years, with more procedures performed in male patients (67.3%). The average length of surgeon experience was 19.7 ± 11.4 years, with an average annual procedural volume of 4.0 ± 5.4 ACLRs. Most surgeons were sports trained (n = 55, 64.7%), high experience (n = 44, 57.1%), and low volume (n = 80, 94.1%). There was an increasing annual proportion of ACLRs performed by sports-trained surgeons (R = 0.748, P = .020) and low-experience surgeons (R = 0.940, P < .001). Autograft reconstructions were most often performed by sports-trained (71.2%), low-experience (66.1%), and high-volume (76.9%) surgeons. There was an increasing proportion of autograft ACLRs that used quadriceps tendon among sports-trained (R = 0.739, P = .023), high-experience (R = 0.768, P = .016), and low-volume (R = 0.785, P = .012) surgeons. Independent drilling techniques were used in an increasing proportion of ACLRs performed by non-sports-trained (R = 0.860, P = .003) and high-volume (R = 0.864, P = .003) surgeons. Augmentation of ACLR with concomitant suture augmentation (n = 24, 1.2%) or extra-articular tenodesis (n = 6, 0.3%) was rarely performed.

CONCLUSIONS

In our multicenter institution, the quadriceps tendon autograft has been increasingly used in ACLR by sports-trained, low-volume, and high-experience surgeons. Independent drilling techniques have been increasingly used by non-sports-trained and high-volume surgeons.

CLINICAL RELEVANCE

Surgeons must stay current with the literature that affects their procedures to ensure that evidence-based medicine is being practiced.

Evaluating the quality of systematic reviews of comparative studies in autograft-based anterior cruciate ligament reconstruction using the AMSTAR-2 tool: A systematic umbrella review

PURPOSE

There remains a lack of consensus around autograft selection in anterior cruciate ligament reconstruction (ACLR), though there is a large body of overlapping systematic reviews and meta-analyses. Systematic reviews and their methodological quality were aimed to be further assessed, using a validated tool known as assessing the methodological quality of systematic reviews (AMSTAR-2).

METHODS

MEDLINE, Embase and CENTRAL were searched from inception to 23 April 2023 for systematic reviews (with/without meta-analysis) comparing primary ACLR autografts. A final quality rating from AMSTAR-2 was provided for each study ('critically low', 'low', 'moderate' or 'high' quality). Correlational analyses were conducted for ratings in relation to study characteristics.

RESULTS

Two thousand five hundred and ninety-eight studies were screened, and 50 studies were ultimately included. Twenty-four studies (48%) were rated as 'critically low', 17 (34%) as 'low', seven (14%) as 'moderate' and two (4%) as 'high' quality. The least followed domains were reporting on sources of funding (1/50 studies), the impact of risk of bias on results of meta-analyses (11/36 studies) and publication bias (17/36 studies). There was a significant increase in the frequency of studies graded as 'moderate' compared to 'low' or 'critically low' quality over time (p = 0.020).

CONCLUSION

The methodological quality of systematic reviews comparing autografts in ACLR is low, with many studies being rated lower due to commonly absent aspects of systematic review methodology such as investigating sources of funding and publication bias. More recent studies were generally more likely to be of higher quality. Authors are advised to consult AMSTAR-2 prior to conducting systematic reviews in ACLR.

LEVEL OF EVIDENCE

Level IV.

Preserving the hamstring tendon insertion during ACL reconstruction with an autograft: Systematic literature review

INTRODUCTION

The hamstring tendons (gracilis and semitendinosus) are often used as an autograft for anterior cruciate ligament (ACL) reconstruction. Healing of this graft involves a slow biological process called ligamentization. To encourage this process, some authors have proposed preserving the insertion of the hamstring tendons.

HYPOTHESIS

Leaving the tibial insertion of the hamstring tendons intact will provide better early biological incorporation and superior tibial mechanical fixation resulting in various clinical advantages.

MATERIALS AND METHODS

In January 2022, a systematic literature review was carried out independently by two authors of the Medline, PubMed and Embase databases. The keywords used were "pedicular" or "pedicled" or "preservation of tibial attachment" or "hamstring tibial insertion" AND "ACL reconstruction". Each author's data was analyzed separately.

RESULTS

Sixteen articles were analyzed. Preserving the hamstring tibial insertion during ACL reconstruction improves the graft's biological incorporation during the initial postoperative phase according to clinical studies with MRI analysis and provides a mechanical advantage at the graft's tibial attachment according to biomechanical studies (construct up to 65% stiffer). There was no difference in the clinical and functional scores when compared to the conventional technique in which the hamstring tendons are detached from their tibial insertion.

DISCUSSION

The main conclusion of this systematic literature review was that preserving the hamstring tibial insertion during ACL reconstruction appears to improve the graft's ligamentization with biological and mechanical advantages relative to detaching the hamstring tendons. The clinical and functional results were comparable to other techniques. Prospective studies with large cohorts are still needed to confirm these findings.

LEVEL OF EVIDENCE

IV; Systematic review of literature.

Histopathological Analysis of the Degree of Tendinosis in Failed Anterior Cruciate Ligament Grafts

INTRODUCTION

After reconstruction of the anterior cruciate ligament, the modification processes in the transplanted tendon tissue directly influence the biomechanical properties of the knee. The histopathological alterations in failed grafts have hardly been studied.

OBJECTIVE

Our study focused on examining the presence and extent of tendinosis (low or high grade) in the tendon tissue of failed anterior cruciate ligament reconstructions. We considered its relationship to the type of transplant, the symptoms, the arthroscopic appearance, the mode of trauma, and the timing of the failure.

MATERIALS AND METHODS

The tendon tissue of failed anterior cruciate ligament reconstructions in 30 patients was gathered during revision surgery and its histopathology was analysed for the occurrence of structural alterations. The classification of the tendinosis as low or high grade was semiquantitative based on five qualities. We used a standardised questionnaire to collect patient data and we used the Marburg Arthroscopy Score for the intraoperative evaluation of the graft.

RESULTS

We found histological vitality and, except for two samples, structural alterations consistent with tendinosis, predominantly high grade, in all failed anterior cruciate ligament grafts. No direct link could be proved between the degree of tendinosis and the type of graft used, the symptoms (except for instability) or the timing of the graft failure, the mode of trauma, or the arthroscopic appearance of the failed plasty. However, the accumulation of high-grade tendinosis in patients with hamstring tendons, subjective instability, and graft failure between 1 to 5 years postoperatively was noteworthy.

CONCLUSION

Structural alterations consistent with tendinosis could be detected, with different expressions, in the vital tendon tissue of anterior cruciate ligament reconstructions. This indicates that the graft is subject to repetitive microtrauma. However, it is still unclear how tendinosis influences the failure of anterior cruciate ligament reconstructions.

ACL Reconstruction With Quadriceps Soft Tissue Autograft Versus Bone-Patellar Tendon-Bone Autograft in Cutting and Pivoting Athletes: Outcomes at Minimum 2-Year Follow-up

Background

The optimal graft choice for anterior cruciate ligament (ACL) reconstruction (ACLR) in the high-level cutting and pivoting athlete remains controversial. Studies have shown similar outcomes when directly comparing bone-patellar tendon-bone (BPTB) autograft versus quadriceps soft tissue (QST) autograft in the general population. However, no studies have directly compared these 2 grafts in athletes participating in cutting and pivoting sports.

Hypothesis

It was hypothesized that, compared with BPTB autograft, the QST autograft would result in similar patient-reported outcomes and rates of retear, return to sport, and complications.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective review was performed on athletes participating in cutting and pivoting sports (soccer, American football, lacrosse, and basketball) who underwent primary ACLR with either BPTB autograft or QST autograft chosen by the athlete between January 2015 and January 2019. The International Knee Documentation Committee (IKDC) subjective knee evaluation and Lysholm Knee Scoring Scale were used to evaluate patient-reported outcomes. Return-to-sport and complication rates were identified. Descriptive statistics were expressed using Mann-Whitney test or Student t test for continuous variables and the chi-square test for categorical variables.

Results

A total of 68 athletes (32 QST, 36 BPTB) were included for analysis. The percentage follow-up was 89% (32/36) for the QST autograft group and 86% (36/42) for the BPTB autograft group. The 2-year IKDC score (QST, 90.5 ± 6.6 vs BPTB, 89.7 ± 7.8) and 2-year Lysholm score (QST, 91.3 ± 7.5 vs BPTB, 90.5 ± 8.6) were similar between groups. The percentage of athletes able to return to sport within the follow-up period was also similar (88% vs 83%; P = .63). There were 2 retears requiring revision in the BPTB group (6%) and no retears in the QST group (P = .18). One contralateral ACL rupture occurred in the QST group (3%) and 4 in the BPTB group (11%) (P = .21).

Conclusion

The QST and BPTB autografts demonstrated similar patient-reported outcomes, return-to-sport rates, and complication rates after primary ACLR at 2-year follow-up. Both autografts appear to be reliable and consistent options for ACLR in the cutting and pivoting athlete.

Allograft Anterior Cruciate Ligament Reconstruction Fails at a Greater Rate in Patients Younger Than 34 Years

Purpose

To characterize the secondary anterior cruciate ligament (ACL) injury rates after primary allograft anterior cruciate ligament reconstruction (ACLR) and to identify the age cut-score at which the risk of allograft failure decreases.

Methods

All patients who underwent primary ACLR within a single orthopaedic department between January 2005 and April 2020 were contacted at a minimum of 2 years post-ACLR to complete a survey regarding complications experienced post-surgery, activity level, and perceptions of knee health. Patients were excluded for incidence of previous ACLR (ipsilateral or contralateral) and/or age younger than 14 years. Relative proportions were calculated, binary regression analysis was performed, and receiver operating characteristic analysis was used to identify the threshold age for maximal sensitivity and specificity to predict high risk of allograft failure, defined as undergoing revision ACLR.

Results

Of the 939 surveys completed, 398 patients underwent primary allograft ACLR (mean age 39.5 years; range 16.0-66.1 years; 54.3% female). The secondary ACL injury rate was 11.6% (5.8% ipsilateral revision ACLR, 5.8% contralateral ACL injury). Male and female patients had similar revision (5.5% male, 6.0% female, P = .82) and contralateral ACL injury rates (6.6% male, 5.1% female, P = .52). Receiver operating characteristic analysis indicated that age ≤34 years was threshold for differentiating high risk of allograft failure (area under the curve 0.65, 95% confidence interval 0.55-0.76; P = .014). Patients aged ≤34 years had a greater secondary injury rate than patients >34 years (20.4% (10.2% revision ACLR, 10.2% contralateral ACL injury) versus 6.9% (3.5% revision ACLR, 3.5% contralateral ACL injury; P < .001). Binary regression analysis demonstrated that decreasing age was associated with increased risk of graft failure (χ2 = 7.9, P = .02.).

Conclusions

Allograft ACLR showed similar failure rates between sexes but displayed suboptimal graft failure outcomes in younger and active patients. By age 34 years, the increased revision risk for younger patients diminished.

Level of Evidence

Level IV, therapeutic case series.

Association of Tibial Tubercle-Trochlear Groove Distance With Risk of ACL Graft Failure

Background

Limited evidence suggests a positive correlation between tibial tubercle-trochlear groove (TT-TG) distance and the risk of native anterior cruciate ligament (ACL) tear. The relationship between TT-TG distance and the risk of ACL graft failure is unknown.

Hypothesis

TT-TG distance is independently associated with risk of ACL graft failure.

Study Design

Cohort study; Level of evidence, 3.

Methods

All patients who underwent ACL revision surgery between 2010 and 2018 at a single institution were identified. A control cohort underwent primary ACL reconstruction (ACLR) between 2006 and 2015, with no evidence of graft failure at 8.1 ± 2.5 years postoperatively. Record review included anthropometrics, graft type, and estimated Tegner activity score at ≥6 months after primary ACLR. Magnetic resonance imaging (MRI) scans after native ACL tear (controls) or graft failure (revision cohort) were assessed for (1) TT-TG distance, (2) proximal tibial slopes, (3) depth of tibial plateau concavity, and (4) tunnel position (revision cohort). Associations between ACL graft failure and MRI measurements, surgical variables, and patient characteristics were evaluated with logistic regression analyses. Sensitivity analyses, excluding patients with tunnel malposition, were performed to confirm multivariable results in patients with "ideal" tunnel placement.

Results

Participants included 153 patients who underwent revisions and 144 controls. Controls were older than the patients who underwent revision (26.6 ± 8.8 vs 20.6 ± 7.3 years; P < .001). The mean TT-TG distance and lateral posterior tibial slope (PTS) were smaller for the control group than for the revision group (TT-TG: 9.3 ± 3.9 vs 11.2 ± 4.2 mm; P < .001; lateral PTS: 6.2° ± 3.3° vs 7.2° ± 3.6°; P = .01). TT-TG distance, lateral PTS, and age were associated with risk of ACL graft failure by multivariable analysis (OR, 1.15; 95% CI, 1.07-1.23; P < .001; OR, 1.13; 95% CI, 1.04-1.22; P = .004; and OR, 0.90; 95% CI, 0.87-0.94; P < .001, respectively). With sensitivity analyses, TT-TG distance, lateral PTS, and age at index surgery remained significantly and independently associated with ACL graft failure.

Conclusion

Increased TT-TG distance, increased lateral PTS, and younger age are independently associated with increased odds of ACL graft failure. Patients with these characteristics may require a more comprehensive strategy to reduce the risk of ACL reinjury.

Mid-Term Outcomes of the All-Soft Quadriceps Tendon Autograft Are Noninferior to Hamstring Autograft in Primary Anterior Cruciate Ligament Reconstruction: Comparison With Minimum 5-Year Follow-Up

PURPOSE

To compare the 5-year clinical and functional outcomes of the soft-tissue quadriceps tendon (QT) with those of the hamstring tendon (HT) autograft.

METHODS

A retrospective review of patients undergoing anterior cruciate ligament reconstruction using either soft-tissue QT or double-tendon HT autograft with at least 5 years of follow-up was conducted. Surgical technique included anteromedial portal creation for the femoral tunnel and transtibial technique for the tibia. Graft fixation was achieved with interference composite screws for the QT and combination of interference composite screw and suture button for the HT cohort. The 2 groups were compared for differences in outcomes, including International Knee Documentation Committee (IKDC) score, Lysholm score, return to sport, and complications.

RESULTS

A total of 37 patients with QT autograft and 46 HT autografts were included in the study, with a mean follow up of 69.9 months and 70.9 months, respectively. The QT group demonstrated a larger graft size on average (9.64 mm vs 7.90 mm, P < .001). The IKDC and Lysholm scores were similar between the 2 groups at 2-years' postoperatively. At 5 years' postoperatively, the QT group demonstrated significantly greater IKDC (P = .018) and Lysholm (P = .007) scores. The cohorts demonstrated similar rates of achieving minimal clinically important difference thresholds at both 2 and 5 years' postoperatively. The 2 groups also demonstrated comparable rates of return to sport, time to return, and postoperative complications.

CONCLUSIONS

Although the QT autograft demonstrated increased patient-reported outcome scores when compared with the HT at 5 years' postoperatively, there was no clinically significant difference between the cohorts at 2 or 5 years' postoperatively. The QT autograft is an effective alternative to HT autograft with noninferior results to the HT autograft at mid-term follow-up.

LEVEL OF EVIDENCE

III, retrospective comparison study.

Hip Abductor and External Rotator Strengths Correlate With Hop Symmetry in Men Athletes 2 Years After Anterior Cruciate Ligament Reconstruction

CONTEXT

Hip muscle strength and hop performance limb symmetries after anterior cruciate ligament reconstruction (ACLR) are not well studied. This study aimed to determine the differences in hip abductors' (ABD) and external rotators' (ER) muscle strength measures between limbs, and the relationship between hip ABD and ER muscle strengths and hop performance limb symmetry indices (LSIs) 2 years after ACLR.

DESIGN

Cross-sectional study.

METHODS

Forty (level I/II) men athletes 2 years after unilateral ACLR completed 4 single-legged hop tests and involved hip ABD and ER strength testing (maximum voluntary isometric contraction [MVIC]; isokinetic peak torque [PKTQ] at 60°, 180°, and 300°/s; and isotonic peak velocity at 75% of their MVICs). Muscle strength measures were normalized to body mass, and hop performances were reported as LSIs. Paired t test was used to determine strength differences between limbs, and the Pearson correlation coefficient was used to assess the relationship between involved hip muscle strength measures and hop performance LSIs.

RESULTS

Hip ER-MVIC (involved: 60.26 [12.01], uninvolved: 63.68 [13.17] N·m/kg) and ER eccentric PKTQ at 60°/s (involved: 32.59 [9.28]; uninvolved: 35.73 [10.50] N·m/kg) were significantly different between limbs (P ≤ .018). Single-hop LSI correlated with hip ER-PKTQ at 180°/s (r = .354) and 300°/s (r = .324, P ≤ .041), while triple-hop LSI correlated with hip ER-MVIC (r = .320), concentric ER-PKTQ at 180°/s (r = .355), eccentric ER-PKTQ at 60°/s (r = .314), and hip ABD-PKTQ at 60°/s (r = .364) and 300°/s (r = .336, P ≤ .049).

CONCLUSIONS

Men athletes demonstrated symmetrical hop performance and hip muscle strengths, except for ER hip's MVIC and isokinetic eccentric peak torque at 60°/s 2 years after ACLR. Hop performance LSIs had a few, yet positive moderate relationships with involved hip ABDs and ER strength measures. This may indicate that hip ABD and ER muscle strength measures contribute to athletes' hop performances 2 years after ACLR. Post-ACLR rehabilitation programs might incorporate hip muscle strengthening training to improve athletes' functional performances.

Comparative Study of ACL Reconstruction With Hamstring Versus Patellar Tendon Graft in Young Women: A Cohort Study From the New Zealand ACL Registry

BACKGROUND

Young female athletes are a specific population that is at high risk of primary anterior cruciate ligament (ACL) rupture and subsequent graft failure. Despite large numbers of ACL reconstructions being carried out in young women, there is limited analysis of outcomes in this group, leading to low levels of evidence for graft choice.

PURPOSE

To assess the effect of graft choice on ACL reconstruction failure rates among young women in New Zealand.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Prospective data captured by the New Zealand ACL Registry between April 2014 and March 2022 were reviewed. Young women aged 15 to 20 years were included. The primary outcome measure was ACL graft failure during the study period, with the key independent variable being graft type, either patellar or hamstring tendon autograft. This is presented as the rate per 100 patient-years and is compared between the 2 groups using the hazard ratio generated from a Cox proportional hazards regression. Secondary outcome measures were Marx activity scores and the Knee injury and Osteoarthritis and Outcome Score patient-reported outcome measure.

RESULTS

A total of 1261 primary ACL reconstructions in young women aged 15 to 20 years were reviewed. Hamstring tendon grafts were used in 797 (63%) reconstructions and patellar tendon graft in 464 (37%) reconstructions. Patients with a hamstring tendon graft had a graft failure rate of 7.7% compared with 1.1% in patients with a patellar tendon graft (hazard ratio, 6.1; 95% CI, 2.4-15.1; P < .001). The number of failures per 100 person-years was significantly higher in the hamstring group (2.05) compared with the patellar tendon group (0.37). No difference was noted at final follow-up between the hamstring tendon and patellar tendon groups when comparing patient-reported outcome measures during the follow-up period.

CONCLUSION

In the young female population of this study, the use of a patellar tendon graft was associated with reduced risk of graft failure and was not associated with an increase in knee morbidity. This highlights the importance of informed decision-making in this high-risk population when considering ACL reconstruction graft type.

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.

The effect and safety of periarticular multimodal drug injection without morphine and epinephrine in anterior cruciate ligament reconstruction

Background

Periarticular multimodal drug injection (PMDI) is a safe and effective pain management technique after anterior cruciate ligament reconstruction (ACLR); however, adding morphine and epinephrine sometimes causes adverse effects. Therefore, we evaluated the efficacy of PMDI without morphine and epinephrine after ACLR.

Methods

This retrospective matched case-control study included patients who had undergone primary double-bundle ACLR with PMDI and were then matched one-to-one with a control group without PMDI based on sex, age, and body mass index using propensity-matched analysis. The following clinical outcomes were compared between the groups: visual analog scale (VAS) score, C-reactive protein (CRP) concentration, number of times the patients used additional analgesics, complication rate, and postoperative time to achieve straight leg raise (SLR).

Results

Twenty-nine patients with PMDI and 29 controls were enrolled. The VAS score at 1 day postoperatively was lower in the PMDI than the control group (1.93  ±  1.44 vs. 3.41  ±  1.75, respectively; P < 0.001). The CRP concentration at 1 and 3 days was lower in the PMDI than the control group (0.46  ±  0.47 vs. 1.00  ±  0.69 mg/dL, P < 0.001; and 1.93  ±  1.71 vs. 4.01  ±  2.55 mg/dL, P < 0.001, respectively). The average number of additional analgesics used was significantly lower in the PMDI than the control group. There were no significant differences in the frequency of occurrence of postoperative complications between the two groups. The number of patients who could achieve SLR within 1 day was 27/29 (93%) in PMDI group, which was significantly higher than the control group (12/29, 41%) ( P < 0.001).

Conclusion

PMDI without morphine and epinephrine after ACLR reduced patients’ subjective pain level, objective inflammatory response without complications and enabled patients to achieve early functional recovery.

Bone-Patellar Tendon-Bone Autograft Harvest Prolongs Extensor Latency during Gait 2 yr after ACLR

PURPOSE

Bone-patellar tendon-bone (BPTB) graft harvest for anterior cruciate ligament reconstruction alters patellar tendon properties, which inflict poor quadriceps neuromuscular function. BPTB autografts are associated with higher rates of posttraumatic osteoarthritis, which in turn is associated with pathological gait. The purpose of this study was to investigate the latency between the time of peak quadriceps activity and the peak knee flexion moment during gait, between those with BPTB grafts ( n = 23) and other graft types (hamstring autograft or allografts, n = 54), 5 ± 2 months and 2 yr (25 ± 3 months) after anterior cruciate ligament reconstruction. We hypothesized that longer latencies would be observed in the BPTB graft group in the involved limb. We expected latencies to shorten over time.

METHODS

Knee moments and quadriceps EMG were collected during gait, and vastus medialis, vastus lateralis, rectus femoris (RF), and quadriceps latencies were calculated. Linear mixed-effects models were used to compare latencies between graft types and over the two time points.

RESULTS

The main effects of graft type were observed for vastus medialis ( P = 0.005) and quadriceps ( P = 0.033) latencies with the BPTB graft group demonstrating longer latencies. No main effects of graft type were observed for vastus lateralis ( P = 0.051) and RF ( P = 0.080) latencies. Main effects of time were observed for RF latency ( P = 0.022).

CONCLUSIONS

Our hypothesis that the BPTB graft group would demonstrate longer extensor latency was supported. Contrary to our second hypothesis, however, latency only improved in RF and regardless of graft type, indicating that neuromuscular deficits associated with BPTB grafts may persist 2 yr after surgery. Persistent deficits may be mediated by changes in the patellar tendon's mechanical properties. Graft-specific rehabilitation may be warranted to address the long-term neuromechanical deficits that are present after BPTB graft harvest.

Addition of the Sartorius Tendon Improves Biomechanics of a Four-Strand Hamstring Anterior Cruciate Ligament Autograft

PURPOSE

The purpose of this study was to quantify and compare the biomechanical properties and change in graft size when adding the sartorius tendon as a fifth strand to a four-strand ST-G hamstring autograft. Additionally, the sartorius tendon was tested individually to quantify its independent biomechanical properties.

METHODS

Four-strand and five-strand hamstring tendon grafts were harvested from matched cadaveric knees (mean age: 81.6 ± 9.8). These matched grafts were biomechanically tested using a MTS servohydraulic test system at a rate of testing representative of physiologic tears. The mean diameter, cross-sectional area, and ultimate load to failure were quantified and compared with a one-sided, paired Student's t-test. A P < .05 was considered statistically significant.

RESULTS

The mean diameter of the five-strand graft was significantly larger than the four-strand graft (9.30 ± .84 mm vs 8.10 ± .42 mm; P = .002). The average ultimate load to failure of the five-strand graft was 65.3% higher than the four-strand graft (2984.05 ± 1085.11 N vs. 1805.03 ± 557.69 N; P = .009) and added 14.8% to the diameter of the four strand ST-G autograft.

CONCLUSIONS

The addition of the sartorius tendon to a four-strand hamstring autograft significantly increased ultimate load to failure by 65%, graft cross-sectional area by 32%, and graft diameter by 15% compared to a traditional four-strand ST-G autograft. This information can be helpful to surgeons who wish to improve the strength of a four-strand ST-G autograft and for undersized grafts as an alternative to allograft supplementation.

CLINICAL RELEVANCE

The addition of the sartorius to the four-strand ST-G hamstring autograft significantly increases the ultimate load to failure and overall graft diameter, which can be particularly helpful in undersized autografts as an alternative to allograft supplementation.

Can Increased Locomotor Task Difficulty Differentiate Knee Muscle Forces After Anterior Cruciate Ligament Reconstruction?

Changes in knee mechanics following anterior cruciate ligament (ACL) reconstruction are known to be magnified during more difficult locomotor tasks, such as when descending stairs. However, it is unclear if increased task difficulty could distinguish differences in forces generated by the muscles surrounding the knee. This study examined how knee muscle forces differ between individuals with ACL reconstruction with different graft types (hamstring tendon and patellar tendon autograft) and "healthy" controls when performing tasks with increasing difficulty. Dynamic simulations were used to identify knee muscle forces in 15 participants when walking overground and descending stairs. The analysis was restricted to the stance phase (foot contact through toe-off), yielding 162 separate simulations of locomotion in increasing difficulty: overground walking, step-to-floor stair descent, and step-to-step stair descent. Results indicated that knee muscle forces were significantly reduced after ACL reconstruction, and stair descent tasks better discriminated changes in the quadriceps and gastrocnemii muscle forces in the reconstructed knees. Changes in quadriceps forces after a patellar tendon graft and changes in gastrocnemii forces after a hamstring tendon graft were only revealed during stair descent. These results emphasize the importance of incorporating sufficiently difficult tasks to detect residual deficits in muscle forces after ACL reconstruction.

No Difference in Complication Rates or Patient-Reported Outcomes Between Bone–Patella Tendon–Bone and Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction

Purpose

To compare subjective outcomes and complications of anterior cruciate ligament reconstruction (ACLR) using either bone–patellar tendon–bone (BPTB) or quadriceps tendon (QT) autograft.

Methods

A retrospective analysis of prospectively collected data identified consecutive cohorts of patients undergoing ACLR with either BPTB or QT autograft. Patients with less than 12-month follow-up and those undergoing concomitant osteotomies, cartilage restoration, and/or other ligament reconstruction procedures were excluded. Pre- and postsurgical patient-reported outcomes including International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score, Patient-Reported Outcomes Measurement Information System (PROMIS), Single Assessment Numeric Evaluation, Tegner, and Marx were compared between groups. Complications requiring reoperation were recorded.

Results

One hundred nineteen patients met inclusion criteria, including 39 QT autografts and 80 BPTB autografts. Demographic information was comparable between groups. Mean follow-up was comparable between groups (QT 22.4 ± 10.6 months vs BPTB 28.5 ± 18.5 months, P = .06). At minimum 12-month follow-up (range 12.0-100.8 months), patients in both groups demonstrated statistically significant improvements in International Knee Documentation Committee (QT 60.0%, P < .0001; BPTB 57.7%, P < .0001), all Knee Injury and Osteoarthritis Outcome Score domains, PROMIS Mobility T-Score (QT 27.2%, P = .0001; BPTB 23.2%, P < .0001), PROMIS Global Physical Health (QT 14.4%, P = .002; BPTB 13.4%, P = .001), PROMIS Physical Function (QT 29.6%, P < .0001; BPTB 37.1%, P < .0001), PROMIS Pain Interference (QT –16.5%, P < .0001; BPTB –20.8%, P < .0001), Single Assessment Numeric Evaluation, (QT 76.9%, P < .0001; BPTB 73.3%, P < .0001), Tegner (QT 92.9%, P = .0002; BPTB 101.4%, P < .0001), and Marx (QT –26.6%, P = .02; BPTB –32.0%, P = .0002) with no statistically significant differences between the 2 groups. Overall postoperative reoperation rate did not differ between groups (QT 12.8% vs BPTB 23.8%, P = .2). Revision ACL reconstruction rate did not differ between groups (QT 5.1% vs BPTB 7.5%, P = .6).

Conclusions

Patients undergoing autograft ACLR with either BPTB or QT demonstrated significant subjective improvements in patient-reported outcomes from preoperative values and no statistically significant differences in outcomes between the groups. Complication and revision ACLR rates were similar between the 2 groups.

Level of Evidence

III, retrospective cohort study.

Limited evidence for graft selection in pediatric ACL reconstruction: a narrative review

Anterior cruciate ligament reconstruction is the preferred treatment to anterior cruciate ligament injury. With the increase in anterior cruciate ligament injuries in both adults and skeletally immature patients comes the need for individualized anterior cruciate ligament reconstruction graft selection whether it is the type of graft (auto vs. allograft) or the harvesting site (hamstrings, iliotibial band, quadriceps, patella). Several factors need to be considered preoperatively in order to optimize the patients’ recovery and restore anterior cruciate ligament strength and function. These include age and bone maturity, preoperative knee flexor/extensor strength, sport participation, patient’s needs and anatomical characteristics. This paper aims at bringing evidence supporting the use of a personalized approach in graft selection for faster and more efficient return to sport and propose a theoretical framework to support the approach.

Influence of Patient Demographics and Surgical Characteristics on Pass Rates of Return-to-Activity Tests in Anterior Cruciate Ligament-Reconstructed Patients Before Physician Clearance

OBJECTIVE

To identify the frequency of passing return-to-activity tests after anterior cruciate ligament reconstruction (ACLR) and to investigate the influence of patient-specific factors on pass rates. We hypothesized that isolated strength tests would be most difficult to pass and that graft type would be the most influential factor.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Eighty patients with a history of primary, unilateral ACLR, and 80 healthy controls participated.

INTERVENTIONS

Bilateral isokinetic strength, isometric strength, and single-leg hop tests were recorded during a single visit. The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation measured subjective knee function, and the Tegner Activity Scale measured physical activity level.

MAIN OUTCOME MEASURES

Pass rates were calculated for 3 thresholds of absolute between-limb asymmetry: 0% to 10%, 11% to 15%, and 16% to 20%. Pass rates were compared by sex (male and female), graft type (patellar and hamstrings), meniscal procedure (yes and no), physical activity level (</≥ median Tegner), and time from surgery (</≥ 6 months).

RESULTS

Isokinetic quadriceps strength was consistently most difficult to pass, whereas the 6-meter timed hop and crossover hop tests were easiest. Graft type had the greatest influence on pass rates (isometric quadriceps and hamstring strength, hamstrings-to-quadriceps ratio), followed by time from surgery (6-meter timed hop and crossover hop), physical activity (IKDC), and meniscal procedure (6-meter timed hop).

CONCLUSIONS

Isokinetic quadriceps strength was the most difficult test to pass, and single-leg hop tests were the easiest. Patient-specific factors including graft type, time from surgery, physical activity level, and meniscal procedure may influence the ability to meet return-to-activity criterion after ACLR.

The Minimally Clinically Important Difference and Substantial Clinical Benefit in Anterior Cruciate Ligament Reconstruction: A Time-to-Achievement Analysis

This study examined the time-dependent course of the minimally clinically important difference (MCID) and the substantial clinical benefit (SCB) achievement for International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales following anterior cruciate ligament reconstruction (ACLR). A prospective institutional registry was queried for patients receiving ACLR. The patient-reported outcome measures (PROMs) of interest included the IKDC score and KOOS sub-scales. One hundred forty-three patients (mean±SD age, 30.86±12.78 years; mean±SD body mass index, 25.51±4.64 kg/m²) were included in the analysis. Threshold values for the MCID/SCB were 18.9 of 29.6 on IKDC score, 15.7 of 25.3 on KOOS Symptom, 11.9 of 15.5 on KOOS Pain, 13.3 of 20.0 on KOOS ADL, 25.9 of 35.8 on KOOS Quality of Life (QoL), and 27.0 of 43.0 on KOOS Sport (area under the curve, 0.74-0.91). Overall, MCID achievement rates increased from 28.0% to 42.7% at 6 months to 41.9% to 70.8% at 12 months. Achievement rates of SCB increased from 16.1% to 30.4% at 6 months to 29.3% to 51.8% at 12 months. Statistically significant increases in MCID achievement (chi-square=47.95-79.36, all P<.001) and SCB achievement (chi-square=26.02-53.24, all P<.001) occurred from preoperative to 6-month time points across PROMs. From 6-month to 12-month time points, increases in MCID achievement occurred on IKDC score and KOOS QoL (chi-square=5.53-15.11, P<.001-.009). Statistically significant increases in MCID and SCB achievement occurred from preoperative to 6-month time points across IKDC score and KOOS subscales; however, statistically significant increases in achievement rates from 6 months to 1 year occurred on IKDC score, KOOS QoL, and KOOS Sport. This study underlines the importance of considering psychological factors and rehabilitative milestones when examining the achievement MCID and SCB after ACLR. [Orthopedics. 2021;44(5):299-305.].

Biological modulations to facilitate graft healing in anterior cruciate ligament reconstruction (ACLR), when and where to apply? A systematic review

Background

When and where to apply the biological modulations is effective to promote healing in the anterior cruciate ligament (ACL) reconstruction remains unclear.

Purpose

To perform a systematic review of preclinical animal studies on biological modulation in anterior cruciate ligament reconstruction (ACLR) concerning the time and site of delivery.

Study design

Systematic review of controlled laboratory studies.

Methods

PubMed, Ovid, and Scopus were searched until December 2020 using a combination of keywords and their synonym to retrieve all animal studies about biological modulation in ACLR. Studies that assessed mechanical strength after ACLR and compared with negative control were included. The methodological quality of animal studies was evaluated.

Results

33 studies were included in this review and the majority reported mechanical strength improvement. 79 ​% of studies applied the biological modulations intra-operatively with different delivery systems used. For 21 ​% of post-operative delivery studies, intermittent delivery was tried. 21 of the included studies directly applied the biological modulations in the bone tunnels, 5 studies applied intra-articularly while 7 studies applied both in the bone tunnels and intra-articular part. Biological modulations applied intra-operatively and those applied in both parts showed better mechanical strength increase. A shift of the failure mode of pull-out from the bone tunnel in the early healing phase, to mid-substance rupture in the later phase was observed in most studies.

Conclusion

The improvement of the mechanical strength depends on how the biological modulations (delivery phase, delivery site, delivery form) are applied. The intra-operative delivery showed an overall higher mechanical strength increase and bone tunnel only delivery or intra-articular and bone tunnel both delivery are preferred than intra-articular only delivery. In addition, intra-articular and bone tunnel both delivery can have better mechanical strength increase for a long follow-up time. Thus, intra-operative application with a carrier to control release rate in both parts should be recommended. Further studies are needed to achieve a better healing outcome and more attention should be given to the intra-articular remodeling of the graft along with the tendon bone healing to increase the final mechanical strength.

The Translational potential of this article

Here, a systematic review of preclinical evidence of the time, site and the method the biological modulations being applied for ACLR to improve the graft healing would be performed. After reviewing the available studies, a choice of when and where to apply the biological modulations can achieve better mechanical strength after ACLR can be obtained. It provides evidence for both researchers and clinicians to decide when and where to apply the biological modulations can achieve their best effectiveness for ACLR before implementing. Promoting graft healing with targeted time and targeted site may reduce the risk of graft failure, safeguard return to sport.

Immediate and 6-week effects of wearing a knee sleeve following anterior cruciate ligament reconstruction: a cross-over laboratory and randomised clinical trial

Background

Rehabilitation following anterior cruciate ligament (ACL) reconstructions is based mainly on comprehensive progressive exercise programmes using a multi-dimensional approach. Elastic knee sleeves may be useful adjuncts to rehabilitation. The aim of this study was to determine the immediate and 6-week effects of wearing a knee sleeve on person-reported outcomes and function in participants who had undergone an ACL reconstruction and who had residual self-reported functional limitations.

Methods

Individuals with ACL reconstruction in the previous 6 months to 5 years were recruited. Immediate effects of a commercially-available elastic knee sleeve on single-leg horizontal hop distance were explored using a cross-over design. Following this first session, participants were randomised into a Control Group and a Sleeve Group who wore the sleeve for 6 weeks, at least 1 h daily. Outcome measures for the randomised clinical trial (RCT) were the International Knee Documentation Classification Subjective Knee Form (IKDC-SKF) score, the single-leg horizontal hop distance, and isokinetic quadriceps and hamstring peak torque. Linear mixed models were used to determine random effects. Where both limbs were measured at multiple time points, a random measurement occasion effect nested within participant was used.

Results

Thirty-four individuals (16 women) with ACL reconstruction completed the cross-over trial. Hop distance for the injured side during the sleeve condition increased by 3.6 % (95 % CI 0.4–6.8 %, p = 0.025). There was no evidence of differential changes between groups for the IKDC-SKF (Sleeve Group n = 15; Control Group n = 16; p = 0.327), or relative improvement in the injured side compared to the uninjured side for the physical performance measures (Sleeve Group n = 12, Control Group n = 12; three-way interaction p = 0.533 [hop distance], 0.381 [quadriceps isokinetic peak torque], and 0.592 [hamstring isokinetic peak torque]).

Conclusions

Single-leg hop distance of the ACL reconstructed side improved when wearing a knee sleeve. Wearing the knee sleeve over 6 weeks did not lead to enhanced improvements in self-reported knee function, hop distance and thigh muscle strength compared to the control group.

Trial registration

The trial was prospectively registered with the Australia New Zealand Clinical Trials Registry No: ACTRN12618001083280, 28 June 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04540-x.

Risk Factors for Requiring a Revision Anterior Cruciate Ligament Reconstruction: A Case-Control Study

Anterior cruciate ligament (ACL) reconstruction is considered as a successful orthopaedic procedure that attempts to help patients return to their preinjury level of activity. However, some patients may need to undergo revision surgery, and this potentially may be associated with certain surgery-specific or patient risk factors. Therefore, the purpose of this study was to assess the potential role of (1) demographics, (2) family history, (3) graft choice, (4) sport, and (5) mechanism of injury (contact vs. noncontact) in the risk for needing a revision ACL for improved clinical outcomes. All patients who had undergone a primary ACL reconstruction between 2012 and 2016 were identified from at a single institution. About 312 patients who had a mean age of 24 years (range, 9-62 years) and a mean follow-up of 4 years (range, 1-10). Patients were further evaluated to identify those who had a revision. There were 19 patients (6.1%) with a mean age of 22 years (range, 13-38 years) and a mean follow-up of 5 years (range, 1-10) that required a revision reconstruction. Gender ratios (p = 0.56) and mean age (p = 0.44) were similar among the cohorts. Family history of ACL reconstruction had no association with revision risk (p = 0.57). Those with tibialis anterior allografts (37 vs. 4%; p = 0.0001) and hamstring allografts (16 vs. 1%; p = 0.0001) were far more likely to undergo a revision. Bone-tendon-bone (BTB) patella autografts were less likely (26 vs. 73%; p = 0.0001). Sport did not play a role in revision with those injured playing basketball (p = 0.61), football (p = 0.52), lacrosse (p = 0.52), soccer (p = 0.83), and volleyball (p = 0.61). There were a greater percentage of contact injuries that required revision (95 vs. 77%; p = 0.07). Graft selection played a significant role in requiring revision surgery with allografts portending to higher revision rates and BTB patella autografts conferring a lower risk.

High variability in anterior cruciate ligament femoral footprint: Implications for anatomical anterior cruciate ligament reconstruction

BACKGROUND

The study aimed to (1) investigate the variability of the femoral ACL center in ACL-ruptured patients, (2) identify whether the currently available over-the-top femoral ACL guides could allow for anatomical reconstruction of the native ACL footprint.

MATERIAL AND METHODS

Magnetic resonance images of 95 knees with an ACL rupture were used to create three-dimensional models of the femur. The femoral ACL footprint area was outlined on each model, and the location of the femoral ACL center was reported using an anatomical coordinate system. The distance of the femoral ACL center from the over-the-top position was measured.

RESULTS

The femoral ACL center demonstrated a high intersubject variability ranging from 1.8 mm (9%) to 12.3 mm (60%) posterior and from 7.7 mm (37%) distal to 4.8 mm (23%) proximal using the posterior condyle circle reference. The average distance of the femoral ACL center from the over-the-top position was 1.9 ± 1.5 mm posterior and 13.8 ± 2.7 mm distal, respectively. The contemporary over-the-top femoral ACL aimers could restore the femoral ACL center in only 6.5% of the patients.

CONCLUSIONS

The femoral ACL center demonstrated a high variation on its location, which resulted in a high intersubject variability from the over-the-top position. The contemporary over-the-top femoral tunnel guides do not provide sufficient offset to allow for an anatomical ACL reconstruction. Anteromedial-portal specific femoral ACL guides with a femoral offset ranging from 10 to 18 mm in the proximal/distal direction are required to restore the native ACL footprint.

Comparison of hamstring and quadriceps tendon autografts in anterior cruciate ligament reconstruction with gait analysis and surface electromyography

BACKGROUND

Anterior cruciate ligament (ACL) tear is the most frequent ligamentous injury of the knee joint. Autografts of hamstring (HS) or quadriceps tendons (QT) are used for primary ACL reconstruction. In this study, we planned to examine whether harvesting an HS graft is related to a deficit in dynamic knee stabilisation and strength revealed by dynamic valgus as compared with QT graft or the uninjured leg. Furthermore, if this deficit exists, is it compensated by higher neuromuscular activity of the quadriceps muscle?

MATERIALS AND METHODS

Adult patients who had undergone ACL reconstruction with QT or HS autografts were included in this two-armed cohort study. Clinical outcome was assessed by clinical data analysis, physical examination and the Lysholm Score and Knee Injury and Osteoarthritis Score (KOOS). In addition, gait analysis and non-invasive surface electromyography were performed.

RESULTS

A complete data set of 25 patients (QT: N = 8, HS: N = 17) was analysed. There was no significant demographic difference between the groups. Time between surgery and follow-up was significantly longer for the QT group. Significant differences regarding clinical outcome were not found between the treated and untreated leg or between the two groups, with excellent scores at the time of follow-up. Gait analysis revealed no significant differences of varus-valgus angles. Significant differences in surface electromyography were only found in the QT group with increased vastus medialis obliquus activity of the treated legs (p < 0.01).

CONCLUSIONS

Our results suggest that harvesting of HS grafts for primary ACL reconstruction will not lead to a medial collapse and consequently impaired medial stabilisation of the knee when compared with QT grafts.

LEVEL OF EVIDENCE

IV.

Pain Following Single-bundle versus Double-bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review

BACKGROUND: Double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) has been known to result in better functional outcomes, joint stability, and lower revision rates compared to single-bundle (SB) ACLR. However, given the increased invasiveness and damage to the surrounding tissue area, it is proposed that it may be associated with increased pain. AIM: This review aims to gather all studies and literature that reported pain as an outcome when comparing SB versus DB ACLR. METHODS: Literature searching was conducted across seven search engines for studies reporting pain as an outcome and comparing SB versus DB ACLR. RESULTS: Eight studies met the eligibility criteria and were included in the study. Overall, the studies show variable findings regarding pain in DB compared to SB ACLR, with the only statistically significant results from two studies indicating that DB ACLR is associated with more pain than SB ACLR. CONCLUSION: Based on the limited evidence available, no conclusions can be made regarding the pain experienced between people receiving either procedure. This constitutes a need for additional studies with increased follow-up time periods, larger sample size, and better study design.

Graft healing after anterior cruciate ligament reconstruction (ACLR)

Anterior cruciate ligament reconstruction (ACLR) is a commonly performed procedure in Orthopaedic sports medicine. With advances in surgical techniques providing better positioning and fixation of the graft, subsequent graft failure to certain extent should be accounted by poor graft healing. Although different biological modulations for enhancement of graft healing have been tried in different clinical and animal studies, complete graft incorporation into bone tunnels and the “ligamentization” of the intra-articular part have not been fully achieved yet. Based on the understanding of graft healing process and its failure mechanism, the purpose of this review is to combine both the known basic science & clinical evidence, to provide a much clearer picture of the obstacle encountered in graft healing, so as to facilitate researchers on subsequent work on the enhancement of ACL graft healing.

Biceps Femoris Compensates for Semitendinosus After Anterior Cruciate Ligament Reconstruction With a Hamstring Autograft: A Muscle Functional Magnetic Resonance Imaging Study in Male Soccer Players

BACKGROUND

Rates of reinjury, return to play (RTP) at the preinjury level, and hamstring strain injuries in male soccer players after anterior cruciate ligament reconstruction (ACLR) remain unsatisfactory, due to multifactorial causes. Recent insights on intramuscular hamstring coordination revealed the semitendinosus (ST) to be of crucial importance for hamstring functioning, especially during heavy eccentric hamstring loading. Scientific evidence on the consequences of ST tendon harvest for ACLR is scarce and inconsistent. This study intended to investigate the repercussions of ST harvest for ACLR on hamstring muscle function.

HYPOTHESIS

Harvest of the ST tendon for ACLR was expected to have a significant influence on hamstring muscle activation patterns during eccentric exercises, evaluated at RTP in a population of male soccer athletes.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 30 male soccer players with a history of ACLR who were cleared for RTP and 30 healthy controls were allocated to this study during the 2018-2019 soccer season. The influence of ACLR on hamstring muscle activation patterns was assessed by comparing the change in T2 relaxation times [ΔT2 (%) = post-exercise-T2pre-exerciseT2pre-exercise] of the hamstring muscle tissue before and after an eccentric hamstring loading task between athletes with and without a recent history of ACLR through use of muscle functional magnetic resonance imaging, induced by an eccentric hamstring loading task between scans.

RESULTS

Significantly higher exercise-related activity was observed in the biceps femoris (BF) of athletes after ACLR compared with uninjured control athletes (13.92% vs 8.48%; P = .003), whereas the ST had significantly lower activity (19.97% vs 25.32%; P = .049). Significant differences were also established in a within-group comparison of the operated versus the contralateral leg in the ACLR group (operated vs nonoperated leg: 14.54% vs 11.63% for BF [P = .000], 17.31% vs 22.37% for ST [P = .000], and 15.64% vs 13.54% for semimembranosus [SM] [P = .014]). Neither the muscle activity of SM and gracilis muscles nor total posterior thigh muscle activity (sum of exercise-related ΔT2 of the BF, ST, and SM muscles) presented any differences in individuals who had undergone ACLR with an ST tendon autograft compared with healthy controls.

CONCLUSION

These findings indicate that ACLR with a ST tendon autograft might notably influence the function of the hamstring muscles and, in particular, their hierarchic dimensions under fatiguing loading circumstances, with increases in relative BF activity contribution and decreases in relative ST activity after ACLR. This between-group difference in hamstring muscle activation pattern suggests that the BF partly compensates for deficient ST function in eccentric loading. These alterations might have implications for athletic performance and injury risk and should probably be considered in rehabilitation and hamstring injury prevention after ACLR with a ST tendon autograft.

Hamstrings substitution via anteromedial portal with optional anterolateral ligament reconstruction is the preferred surgical technique for anterior cruciate ligament reconstruction: a survey among ESSKA members

PURPOSE

The objective of this study was to report on a worldwide web-based survey among the ESSKA community developed to investigate current recommendations regarding ACL reconstruction surgical procedures.

METHODS

All contacts in the official mailing list of the ESSKA were contacted to investigate preferences regarding graft type, anterolateral ligament reconstruction, femoral tunnel drilling technique, single-bundle vs double-bundle technique, femoral and tibial fixation methods.

RESULTS

Eight-hundred and twenty responses were analyzed. Hamstrings autograft was the graft of choice in male patients for 634 (79%) and in female patients for 674 (84%) responders, while its preference for ACL reconstruction in professional athletes was for 401 (50%). 480 (63%) surgeons surveyed would include anterolateral ligament reconstruction only if diagnosed and remaining instability after ACL surgery or revision. 598 (75%) respondents were in favor of anteromedial portal for femoral tunnel drilling. The most popular femoral fixation technique was found to be cortical suspension (500-66%), while a compression system was preferred on the tibial side by 537 (71% of the sample).

CONCLUSIONS

This survey study found that HT autograft, single-bundle reconstruction, anteromedial portal for femoral tunnel drilling, cortical suspension systems for femoral fixation and compression systems for tibial fixation represent the current standard of ACLR in a large community of orthopedic surgeons. The present study performed with surgeons who are members of the ESSKA community will help to comprehend the actual ACLR worldwide practice patterns. Due to low response rate, these results should be interpreted with caution and not to be intended to represent the state of the art of ESSKA community.

LEVEL OF EVIDENCE

III.

A Novel Approach to Augmenting Allograft Hamstring Anterior Cruciate Ligament Reconstructions Utilizing a Resorbable Type I Collagen Matrix with Platelet Rich Plasma

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is one of the most common lower extremity orthopedic surgeries performed in the United States. Annually, between 100,000 and 200,000 ACL tears affect 1 in 3,000 people. The selection of autograft versus allograft for ACLR has been widely discussed in terms of risk of graft failure. Allograft reconstructions have been shown to have higher rerupture rates. One factor contributing to this risk is delayed biologic graft incorporation.

METHODS

A retrospective review was performed examining 14 patients who underwent an augmented quadruple-stranded hamstring allograft ACLR with a type I resorbable collagen matrix impregnated with platelet-rich plasma (PRP).

RESULTS

Within our clinical practice, the augmentation of quadruple-stranded hamstring allograft ACLR with a type I resorbable matrix impregnated with PRP has yielded good early clinical success at 2-year outcomes (N = 14). Zero ACLR failures have been reported to date in this series.

CONCLUSION

This case series offers a novel approach for soft tissue allograft ACLR augmented with a type I collagen matrix impregnated with PRP. The authors theorize that this augmentation may improve biologic graft incorporation into the host bone tunnels.

Anterior root of lateral meniscus and medial tibial spine are reliable intraoperative landmarks for the tibial footprint of anterior cruciate ligament

PURPOSE

The aims of the present study were (1) to investigate the tibial footprint location of the anterior cruciate ligament (ACL) in both ACL-ruptured and ACL-intact patients, (2) to identify the relationship of the tibial footprint to the anterior root of the lateral meniscus (ARLM) and medial tibial spine (MTS), and (3) to evaluate the reliability of the ARLM and MTS for identifying the center of the tibial ACL footprint.

METHODS

Magnetic resonance images of 90 knees with ACL rupture and 90 matched-controlled knees were used to create three-dimensional models of the tibia. The tibial ACL footprint was outlined on each model, and its location was measured using an anatomical coordinate system.

RESULTS

No significant difference in the location of the tibial footprint was found between ACL-ruptured and ACL-intact knees. The tibial ACL footprint was located in very close proximity to the ARLM, especially in the M/L direction. The safe zone of tibial tunnel reaming for avoiding damage to the ARLM was 2.6 mm lateral to the center of the native tibial footprint. Both the ARLM and MTS were reliable intraoperative landmarks for identifying the tibial footprint.

CONCLUSIONS

Orthopedic surgeons should be aware of the safe zone of tibial tunnel reaming for avoiding injury to the ARLM. Both the ARLM and MTS might be reliable landmarks for identifying the center of the tibial ACL footprint and may facilitate tibial tunnel placement during anatomical single-bundle ACL reconstruction, especially in cases of revision where the tibial ACL stump is not available.

LEVEL OF EVIDENCE

Level III.

Small Size Autograft versus Large Size Allograft in Anterior Cruciate Ligament Reconstruction

Background

A small autograft diameter negatively affects functional outcomes, knee stability, and the risk of rerupture after anterior cruciate ligament (ACL) reconstruction, whereas the strength of allograft decreases over time. Therefore, it is not clear whether the use of smaller autografts or the use of larger allografts in ACL yields better results. The aim of this study was to compare the outcome of smaller autografts and larger allografts for ACL reconstruction.

Methods

Fifty-one patients who underwent ACL reconstruction with hamstring tendon autografts (size ≤ 8 mm) and 21 patients who underwent ACL reconstruction with allografts (size ≥ 10 mm) were included in our study. All patients underwent the same aggressive early postoperative rehabilitation program. There were no significant differences between the autograft and allograft groups regarding the preoperative patient age, sex, time from injury to surgery, and average follow-up time.

Results

The mean diameter of the 4-stranded hamstring tendon grafts used as autografts was 7.48 ± 0.33 mm and the mean diameter of the allografts was 10.76 ± 0.67 mm. According to specific tests for the ACL (anterior drawer, Lachman, and pivot shift) and clinical evaluation tests (Lysholm knee scoring scale and International Knee Documentation Committee questionnaire), the final follow-up results were significantly better than the preoperative status in both autograft and allograft ACL reconstruction groups. Therefore, there were no significant differences between the autograft and allograft groups preoperatively and at the final follow-up.

Conclusions

The large size of the graft in ACL reconstruction has been reported to affect results positively. However, in our study, we could not find any significant differences between the smaller size autografts and larger size allografts in terms of inadequacy, rerupture, and final follow-up functional results. Although allografts were significantly larger than autografts, we did not have the positive effect of larger size grafts. Smaller size autografts were as effective as the larger size allografts.

Supervised Rehabilitation May Lead to Better Outcome than Home-Based Rehabilitation Up to 1 Year after Anterior Cruciate Ligament Reconstruction

Background and objectives: Previous studies consistently found no significant difference between supervised and home-based rehabilitation after anterior cruciate ligament reconstruction (ACLR). However, the function of the nonoperative knee, hamstring strength at deep flexion, and neuromuscular control have been overlooked. This prospective observational study was performed to investigate the outcomes after ACLR in operative and nonoperative knees between supervised and home-based rehabilitations. Materials and Methods: After surgery, instructional videos demonstrating the rehabilitation process and exercises were provided for the home-based rehabilitation group. The supervised rehabilitation group visited our sports medicine center and physical therapists followed up all patients during the entire duration of the study. Isokinetic muscle strength and neuromuscular control (acceleration time (AT) and overall stability index (OSI)) of both operative and nonoperative knees, as well as patient-reported knee function (Lysholm score), were measured and compared between the two groups 6 months and 1 year postoperatively. Results: The supervised rehabilitation group showed higher muscle strength of hamstring and quadriceps in nonoperative knees at 6 months (hamstring, p = 0.033; quadriceps, p = 0.045) and higher hamstring strength in operative and nonoperative knees at 1 year (operative knees, p = 0.035; nonoperative knees, p = 0.010) than the home-based rehabilitation group. At 6 months and 1 year, OSIs in operative and nonoperative knees were significantly better in the supervised rehabilitation group than in the home-based rehabilitation group (operative knees, p < 0.001, p < 0.001; nonoperative knees, p < 0.001, p < 0.001, at 6 months and 1 year, respectively). At 1 year, the supervised rehabilitation group also demonstrated faster AT of the hamstrings (operative knees, p = 0.016; nonoperative knees, p = 0.036). Lysholm scores gradually improved in both groups over 1 year; however, the supervised rehabilitation group showed higher scores at 1 year (87.3 ± 5.8 vs. 75.6 ± 15.1, p = 0.016). Conclusions: This study demonstrated that supervised rehabilitation may offer additional benefits in improving muscle strength, neuromuscular control, and patient-reported knee function compared with home-based rehabilitation up to 1 year after ACLR.

Arthroscopy Primary Double-Bundle Repair of Anterior Cruciate Ligament With Internal Brace Augmentation and a Knotless Anchor Implant

The primary repair technique of acute anterior cruciate ligament (ACL) tears has been controversially discussed over the past few decades. Many different suture techniques have been reported for ACL repair, but these procedures showed high re-rupture rates and poor results. Recently, the literature has reported excellent outcomes with primary ACL repair. There has been a resurging interest in modernizing and augmenting primary ACL repair. This article describes a technique that uses internal brace augmentation and a knotless anchor (Arthrex) implant for primary anatomic double-bundle ACL repair after an acute proximal ACL tear. This technique aims to advocate natural healing by the high-strength internal brace augmentation and knotless anchor as a provisional scaffold during the healing phase and early mobilization. This technique might be an alternative to conventional ACL reconstruction in the appropriate selection of patients.

Similar functional outcomes of arthroscopic reconstruction in patients with isolated Posterior Cruciate Ligament (PCL) and combined Anterior Cruciate Ligament (ACL) and PCL tears

BACKGROUND

Posterior Cruciate Ligament (PCL) injuries seldom occur in isolation and majority occurs in conjugation with other ligament injuries. Posterior Cruciate Ligament (PCL) reconstruction continues to be taken into consideration as a complicated surgical procedure, with heterogeneity in literature regarding clinical and functional outcomes in isolated PCL and combined ACL and PCL injuries.

METHODS

The retrospective evaluation of patients with isolated PCL reconstruction (group 1) and combined Anterior Cruciate Ligament (ACL) and PCL reconstruction (group 2) was performed. A total of 66 patients with either isolated PCL or combined ACL and PCL reconstruction surgeries that met the inclusion criteria, were included in the study. These patients were assessed for functional outcome scores including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Lysholm score, International Knee Documentation Committee (IKDC) and Tegner activity score at a minimum follow-up of 5 years.

RESULTS

The mean follow-up of patients was 82.09 ± 12.43 months in group 1 and 79.36 ± 11.24 months in group 2, with a total of 29 patients in group 1 and 21 patients in group 2. Both the groups were found to be comparable in terms of age, gender, duration of injury and pre-injury Tegner activity level. Post-surgical functional outcome scores (WOMAC score, Lysholm score and Tegner score) were found to be comparable between 2 groups at a mean follow-up of 5 years. Further, 22 patients in group 1 and 16 patients in group 2 had normal or near normal objective IKDC outcome scores at a mean follow-up of 5 years.

CONCLUSIONS

No differences were observed in functional outcome scores (WOMAC score, Lysholm score, Tegner score and IKDC score) between isolated reconstructed PCL and combined ACL and PCL reconstructed patients.

Low knee-related quality of life and persistent physical asymmetries in participants up to 10 years post-ACL reconstruction - A cross-sectional study

OBJECTIVE

To compare self-report and functional outcomes between participants with anterior cruciate ligament reconstruction (ACLR) with age and activity matched controls.

DESIGN

Cross-sectional study.

SETTING

University laboratory-based study.

PARTICIPANTS

Twenty-five participants (30.8 ± 9.7 years; 13 women), two to ten years post anterior cruciate ligament reconstruction; 24 controls (31.0 ± 10 years, 13 women).

MAIN OUTCOME MEASURES

Knee Osteoarthritis and Injury Outcome Score (KOOS), Tegner, Marx Activity and Fear of Re-injury scales, and SF-12; isokinetic quadriceps and hamstring peak torque and single-leg hop distance.

RESULTS

There were no between-groups differences for the Tegner and the Marx Activity Scales. The ACLR group had lower KOOS dimensions (p < 0.001), SF-12 Physical Component Scores (p = 0.008), and higher Fear of Reinjury Scores (<0.001) than the controls. No significant differences were found for physical performance measures between the ACLR and the control groups. Significant between-side differences for the ACLR group were evident for concentric quadriceps (p < 0.001) and concentric hamstring peak torque (p = 0.002), and hop distance (p < 0.001).

CONCLUSION

Knee-specific symptoms and function, activity and quality of life were lower, and fear of re-injury was higher for participants with ACLR than controls. Side-to-side thigh muscle strength and hop distance deficits were evident for the ACLR group.

A study of knee anterior cruciate ligament biomechanics with respect to energy and relaxation

BACKGROUND

This research aimed to study the biomechanical properties of sheep tendon under torsion and the tendon energy absorption performance with an externally imposed initial force.

METHODS

Tendons of nine healthy knees of sheep were investigated. In both tests, we investigated energy and relaxation at rotations of 0°, 90°, 180°, and 360°. For both tensile force and tensile displacement at a sampling period of 100 milliseconds, the maximum value of 89 N was selected as the maximum tension state for 600 s of relaxation duration for testing relaxation, and analysed of the average force of the last 30 s.

FINDINGS

The difference of energy levels of the tendons are significant between twisted groups (180° and 360°) and untwisted group (0°) (P < 0.05); The relaxation force decreases significantly with twisted groups (90°,180°, and 360°) and untwists group (0°) (P < 0.05). The nine-group tendons show no significant difference at torsion 90° and 180° (P = 0.466). Peak force test shows significant differences between the twisted groups (90°,180°, and 360°) and untwisted group (0°) (P < 0.05).

INTERPRETATION

The torsion tendon has lower energy absorption and relaxation than the untwisted counterparts; thus, it may be more prone to damage. These results are useful for providing guidance on anterior cruciate ligament reconstruction.

Anterior Knee Pain After Anterior Cruciate Ligament Reconstruction

Background

Anterior knee pain is a frequent condition after anterior cruciate ligament reconstruction (ACLR), but its origin remains uncertain. Studies have suggested that donor site morbidity in autologous bone-patellar tendon-bone reconstructions may contribute to patellofemoral pain, but this does not explain why hamstring tendon reconstructions may also present with anterior pain.

Purpose

To evaluate the prevalence of anterior knee pain after ACLR and its predisposing factors.

Study Design

Case-control study; Level of evidence, 3.

Methods

We evaluated the records of all patients who underwent ACLR between 2000 and 2016 at a private facility. The prevalence of anterior knee pain after surgery was assessed, and possible risk factors (graft type, patient sex, surgical technique, range of motion) were evaluated.

Results

The records of 438 patients (mean age, 30 years) who underwent ACLR were analyzed. Anterior knee pain was found in 6.2% of the patients. We found an increased prevalence of anterior knee pain with patellar tendon graft, with an odds ratio of 3.4 (P = .011). Patients who experienced extension deficit in the postoperative period had an odds ratio of 5.3 of having anterior pain (P < .001). Anterior knee pain was not correlated with patient sex or surgical technique.

Conclusion

The chance of having anterior knee pain after ACLR was higher when patellar tendon autograft was used compared with hamstring tendon graft, as well as in patients who experienced extension deficit in the postoperative period.

Timing of Muscle Activation Is Altered During Single-Leg Landing Tasks After Anterior Cruciate Ligament Reconstruction at the Time of Return to Sport

OBJECTIVES

It is well known that alterations in landing mechanics persist for years after anterior cruciate ligament reconstruction (ACL-R). Nevertheless, existing literature is controversial in reporting successful or unsuccessful recovery of prelanding muscle activation timing after ACL-R. The study aimed at comparing myoelectric and kinematic patterns during landing tasks between ACL-R and healthy subjects.

DESIGN

Cross-sectional study.

SETTING

Institutional research laboratory.

PATIENTS AND INTERVENTION

Fifteen male athletes after ACL-R using patellar tendon and 11 using hamstrings autograft at the time of return to sport were recruited. Fifteen healthy athletes served as control group. Participants performed 4 different single-leg landing tasks arriving onto a force plate.

MAIN OUTCOME MEASURES

Electromyographic (EMG) activity of knee extensors and flexors, normalized vertical ground reaction force (vGRF), and knee angular displacement were recorded.

RESULTS

In all the tasks, preimpact EMG duration was longer in ACL-R (112 ± 28 ms in the knee extensors; 200 ± 34 ms in the knee flexors) compared with healthy participants (74 ± 19 ms in the knee extensors; 153 ± 29 ms in the knee flexors; P < 0.05). Initial contact (IC) and maximum postimpact knee angle were lower in ACL-R (9 ± 7 degrees at IC; 39 ± 12 degrees at maximum flexion) compared with healthy participants (17 ± 9 degrees at IC; 52 ± 15 degrees at maximum flexion; P < 0.05). Normalized vGRF was higher in ACL-R compared with healthy participants (3.4 ± 0.5 and 2.7 ± 0.6; P < 0.05).

CONCLUSIONS

At the time of return to sport, ACL-R subjects showed altered motor control strategies of single-leg landings. These alterations may lead to uncoordinated movement, hence increasing the risk of reinjury.

The effect of thermosensitive hydrogel platelet-rich-plasma complex in the treatment of partial tear of anterior cruciate ligament in rat model

Background/Objective

The treatment of anterior cruciate ligament (ACL) partial tear is controversial. The reconstructive surgery is invasive while the prevalence of subsequent insufficiency after conservative treatment has been reported to range from 11% to 62%. Therefore, a new method that promotes tissue regeneration is needed. The aim of this study was to observe the healing of ACL partial tear biomechanically and histologically after the administration of a thermosensitive hydrogel platelet-rich-plasma (PRP) complex.

Methods

The complex was prepared according to a previously published protocol. One hundred and fifty 12-week-old male Sprague-Dawley rats were included and they were allocated into 4 groups. Lesion control group (Group 1), treatment group (Group 2), gel-only group (Group 3) and intact group (Group 4). Biomechanical testing, histological analysis (H&E and immunohistochemical staining) and scoring was performed.

Results

On gross observation, the treatment group showed a continuous ACL with slightly thickened synovium or a partially healed ACL at 6-week follow up. In the biomechanical testing at 6 weeks after surgery, the failure load of the treatment group was significantly superior when compared with the lesion control group (52.7±10.8N vs. 41.6±7.8N, p<0.01), but the failure load was not restored to level of the intact group (52.7±10.8N vs. 61.5±9.1N, p=0.037). The maturity index of wound sites showed no significant inter-group differences at any timepoints. However, an increased expression of vascular endothelial growth factor (VEGF) and pro-collagen I was detected.

Conclusion

The thermosensitive hydrogel-PRP was shown to be effective in enhancing the healing of ACL partial tear in the rat model, and potentially this complex can be used as a treatment for patients with ACL partial tear.

The translational potential of this article

The thermosensitive hydrogel-PRP is potentially translated to clinical use to treat patients with ACL partial tear by injection under arthroscopy or ultrasound guiding.

Anterior Cruciate Ligament Repair with Suture Augmentation for Proximal Avulsion Injuries

Purpose

To assess failure rate, outcomes, and patient satisfaction in patients who underwent anterior cruciate ligament (ACL) repair with suture augmentation for clinical instability and proximal avulsion of the ACL.

Methods

We retrospectively reviewed consecutive suture-augmented ACL repairs performed by a single surgeon between January 2014 and June 2016 for proximal ACL avulsion. Patients were included if they were at least 24 months postoperative from repair surgery. Patients were excluded from the study if they underwent primary ACL reconstruction instead of repair or if they had a concomitant multiligamentous knee injury. Knee Injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS), Veterans RAND-12 (VR-12), Marx Activity, and Single Assessment Numeric Evaluation data were collected.

Results

Of 172 patients who underwent ACL surgery between January 2014 and June 2016, 28 (16%) with Sherman type I or II ACL tears or high-grade partial avulsion with clinical instability underwent ACL repair with suture augmentation. One patient was not available for follow-up. The 27 patients were age 27.4 ± 8.6 years, 18 males (66.7%), and 2.8 ± 0.7 years follow-up (range, 2.0-3.8 years). Of these 27 patients, 4 recurrent ACL injuries (14.8%) required revision to reconstruction. The remaining 23 patients had successful ACL repair with no clinical instability and no subjective complaints at final follow-up. Final scores were KOOS 83.7 ± 12.8, Marx 8.6 ± 4.0, VAS 1.1 ± 1.8, physical VR-12 53.6 ± 5.2, mental VR-12 53.1 ± 8.1, and Single Assessment Numeric Evaluation 83.0 ± 12.9. In the 11 patients with baseline data, significant improvements were observed in composite KOOS (50.4 ± 11.5 to 85.7 ± 8.4; P < .001; VAS: 3.9 ± 2.6 to 0.8 ± 0.8; P = .002; and physical VR-12: 39.9 ± 6.5 to 55.5 ± 3.3; P < .001). All 11 patients (100%) met or exceeded the KOOS composite minimum clinically important difference (mean 34.0 increase).

Conclusions

In patients with proximal ACL avulsion, arthroscopic primary ACL repair with suture augmentation demonstrated high functional outcome and improved patient-reported outcomes at 2-year follow-up. The rate of graft failure was 15%.

Level of Evidence

Level IV, therapeutic case series.

Editorial Commentary: Graft Choice for Anterior Cruciate Ligament Reconstruction: Will There Ever Be a Correct Answer? Probably Not

Graft choice for anterior cruciate ligament reconstruction has been a great controversy in the sports medicine literature for the last 25 years. It has been well studied in the orthopaedic literature, with numerous randomized control trials and large database studies. There remain advantages and disadvantages to each autograft choice, primarily bone-patellar tendon-bone, quadrupled hamstring, as well as allograft. More recently, quadriceps autograft has also been studied as a suitable alternative. Most studies show nearly equivalent functional outcomes for autograft anterior cruciate ligament using bone-patellar tendon-bone and hamstring autografts in athletes younger than the age of 25 years, whereas allograft may be preferred for older athletes.