Anterior Cruciate Ligament Tear

Study protocol for double-blind, randomised placebo-controlled trial evaluating semitendinosus function and morbidity following tendon harvesting for anterior cruciate ligament reconstruction augmented by platelet-rich plasma

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is debilitating, often requiring surgical reconstruction. An ACL reconstruction (ACLR) using a tendon autograft harvested from the semitendinosus results in substantial injury to the donor muscle. Following ACLR, patients rarely return to their preinjury level of physical activity, are at elevated risk of secondary lower limb injuries and early onset knee osteoarthritis. To date, no randomised controlled trial has evaluated the efficacy of platelet-rich plasma (PRP) in aiding knee function and semitendinosus morphology of following ALCR.

METHODS AND ANALYSIS

This is a multicentre double-blind randomised placebo-controlled trial. Fifty-four ACLR patients aged 18-50 years will be randomised to receive either a single application of PRP (ACLR+) or placebo saline (ACLR) into the semitendinosus harvest zone at the time of surgery. All patients will undergo normal postoperative rehabilitation recommended by the attending orthopaedic surgeon or physiotherapist. The primary outcome measure is between-limb difference (ACLR compared with intact contralateral) in isometric knee flexor strength at 60o knee flexion, collected 10-12 months postsurgery. This primary outcome measure will be statistically compared between groups (ACLR+ and standard ACLR). Secondary outcome measures include bilateral assessments of hamstring muscle morphology via MRI, biomechanical and electromyographic parameters during an anticipated 45° running side-step cut and multidirectional hopping task and patient-reported outcomes questionaries. Additionally, patient-reported outcomes questionaries will be collected before (baseline) as well as immediately after surgery, and at 2-6 weeks, 3-4 months, 10-12 months and 22-24 months postsurgery 10-12 months following surgery.

ETHICS AND DISSEMINATION

Ethics approval has been granted by Griffith University Human Research Ethics Committee, Greenslopes Research and Ethics Committee, and Royal Brisbane & Women's Hospital Human Research Ethics Committee. Results will be submitted for publication in a peer-reviewed medical journal.

TRIAL REGISTRATION NUMBER

ACTRN12618000762257p.

Anterior cruciate ligament tear increases the risk of venous thromboembolism: a population-based cohort study

PURPOSE

Previous studies highlighted an increased risk of venous thromboembolism (VTE) among patients with anterior cruciate ligament reconstruction (ACLR); however, the risk for those with ACL tear but without undergoing ACLR has not been reported yet. The aim of this study was to evaluate the risk of VTE among ACL tear individuals with or without ACLR derived from the general population.

METHODS

A cohort study was conducted using data from the IQVIA Medical Research Database of the United Kingdom. Up to five non-ACL tear individuals (n = 22,235) were matched to each case of ACL tear (n = 4474) by age, sex, body mass index and entry-time. The relation of ACL tear to VTE [pulmonary embolism (PE) and deep vein thrombosis (DVT)] was examined using a multivariable Cox proportional hazard model. A sub-cohort analysis, in which the ACL tear individuals were stratified into those with ACLR and those without ACLR, was also conducted.

RESULTS

VTE developed in 13 individuals with ACL tear and nine individuals without ACL tear (incidence rates: 3.1 vs. 0.4/1000 person-years), with multivariable-adjusted hazard ratio (HR) being 6.59 (95% CI 2.28-19.08) in 1-year follow-up. For ACL tear individuals with ACLR, the HR was 11.44 (95% CI 2.71-48.28), and for those without ACLR, the HR was 6.02 (95% CI 1.44-24.25), compared with individuals without ACL tear.

CONCLUSION

This large-sample population-based cohort study provides the first evidence on an increased risk of VTE in ACL tear individuals regardless of subsequent ACLR, which supports the necessity for monitoring venous-thromboembolic complications in the target population, including those without ACLR.

LEVEL OF EVIDENCE

III.

Revision Rates After Primary ACL Reconstruction Performed Between 1969 and 2018: A Systematic Review and Metaregression Analysis

Background:

Numerous studies, including randomized controlled trials (RCTs), have been published on the optimal graft choice for primary anterior cruciate ligament (ACL) reconstruction.

Purpose:

To review existing studies to investigate whether advances in orthopaedics have affected revision rates after primary ACL reconstruction.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The PubMed database was searched from inception to December 31, 2020, using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Patient series, observational studies, clinical trials, and registry-based studies investigating primary ACL reconstruction were included, as were high-quality RCTs from an additional study. The minimum required follow-up time for inclusion was 1 year. The primary outcome measure was the pooled prevalence of revision ACL reconstruction. The effect of the year the surgery was performed on revision rates was evaluated with metaregression analysis. All graft types were analyzed simultaneously, and all analyses were repeated separately for each graft type.

Results:

Overall, 330 articles with 52,878 patients were included, with a median patient age of 28 years (range, 15-57 years). The primary ACL reconstructions were performed between 1969 and 2018. At a median of 2.3 years of follow-up, the overall revision rate was 3.14% (95% CI, 2.76% to 3.56%); it was 2.71% (95% CI, 2.25% to 3.27%) for hamstring autografts, 2.38% (95% CI, 1.82% to 3.11%) for bone–patellar tendon–bone (BPTB) autografts, and 5.24% (95% CI, 4.02% to 6.80%) for other graft types. For hamstring grafts, the revision rate increased over time (year of surgery), with a 0.0434 (95% CI, 0.0150 to 0.0718) increase effect in the logit-transformed scale for every additional year. There was a slight decrease in revision rates for BPTB (β = –0.0049; 95% CI, –0.0352 to 0.0254) and other graft types (β = –0.0306; 95% CI, –0.0608 to −0.0005) over time; however, confidence intervals for BPTB included the zero change.

Conclusion:

Based on this systematic review and meta-analysis, ACL reconstruction is a reliable procedure with overall low historical revision rates. BPTB autograft had the lowest revision rate and a slightly decreasing trend of failures during the past 45 years, although both BPTB and hamstring autografts are reliable graft choices.

Low-level laser therapy attenuates arthrogenic contracture induced by anterior cruciate ligament reconstruction surgery in rats

Therapeutic approaches to treat joint contracture after anterior cruciate ligament (ACL) reconstruction have not been established. Arthrofibrosis accompanied by joint inflammation following ACL reconstruction is a major cause of arthrogenic contracture. In this study, we examined whether anti-inflammatory treatment using low-level laser therapy (LLLT) can prevent ACL reconstruction-induced arthrogenic contracture. Rats underwent ACL transection and reconstruction surgery in their right knees. Unoperated left knees were used as controls. After surgery, rats were reared with or without daily LLLT (wavelength: 830 nm; power output: 150 mW; power density: 5 W/cm2; for 120 s/day). We assessed the passive extension range of motion (ROM) after myotomy at one and two weeks post-surgery; the reduction in ROM represents the severity of arthrogenic contracture. ROM was markedly decreased by ACL reconstruction at both time points; however, LLLT partially attenuated the decrease in ROM. One week after ACL reconstruction, the gene expression of the proinflammatory cytokine interleukin-1beta in the joint capsule was significantly upregulated, and this upregulation was significantly attenuated by LLLT. Fibrotic changes in the joint capsule, including upregulation of collagen type I and III genes, shortening of the synovium, and thickening were caused by ACL reconstruction and seen at both time points. LLLT attenuated these fibrotic changes as well. Our results indicate that LLLT after ACL reconstruction could attenuate the formation of arthrogenic contracture through inhibition of inflammation and fibrosis in the joint capsule. Thus, LLLT may become a novel therapeutic approach for ACL reconstruction-induced joint contracture.

Anterior Cruciate Ligament Reconstruction with Autologous Hamstring Single- versus Double-Bundle Graft: A Prospective Study with 10-Year Follow-up

The purpose of the present study was to compare the clinical and subjective outcomes of anterior cruciate ligament (ACL) reconstruction using an autologous hamstring double bundle (DB) with a single bundle (SB) after a 10-year follow-up. A prospective comparative cohort study was performed of 47 consecutive patients with ACL rupture included between May 2006 and March 2008. Inclusion criteria were less than 2 years since the injury date, no previous surgery on the affected knee, and having closed growth plates. Patients were divided into two groups: (1) SB group (n = 25) and (2) DB group (n = 22). Patients underwent evaluation before surgery and at 1 and 10 years postoperatively. The clinical evaluation included the International Knee Documentation Committee (IKDC) Questionnaire, pivot shift test, and single hop test, as well as X-rays (anterior drawer X-rays on a Telos stress radiography). Range of motion (ROM) was assessed at 10-year follow-up. Both groups were similar in terms of baseline characteristics. Post hoc power analysis showed that among 30 and 226 patients would be needed for statistical significance, depending on the outcome. With the numbers available, no significant differences were observed in subjective IKDC, anterior stability (measured with Telos), and functional test outcomes (single hop test) between both groups at 1 and 10 years postoperatively. Regarding rotational instability (pivot-shift test), DB group was significantly superior (p = 0.002). Regarding ROM, no significant differences were observed between groups. No failure was registered in any of the groups. ACL reconstruction (ACLR) with an autologous hamstring, both with bundles and DB, shows overall better outcomes compared with the status before surgery. DB ACLR provides better rotational control of the knee, an outcome that is maintained after 10 years.

Sports activity and quality of life improve after isolated ACL, isolated PCL, and combined ACL/PCL reconstruction

PURPOSE

To compare patient-reported outcomes following isolated anterior cruciate ligament reconstruction (ACL-R), isolated posterior cruciate ligament reconstruction (PCL-R), and combined ACL-R and PCL-R (ACL/PCL-R), at a minimum follow-up of 2 years.

METHODS

This was a prospective observational registry cohort study based on the Swedish National Knee Ligament Registry. Patients undergoing isolated ACL-R, isolated PCL-R, and combined ACL/PCL-R between 2005 and 2019 were eligible for inclusion. Demographic characteristics as well as injury- and surgery-related data were queried from the SNKLR. To evaluate functional outcomes, the Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1- and 2-year follow-ups and compared between the treatment groups.

RESULTS

In total, 45,169 patients underwent isolated ACL-R, 192 patients isolated PCL-R, and 203 patients combined ACL/PCL-R. Preoperatively, and at the 1- and 2-year follow-ups, KOOS subscales were highest for the isolated ACL-R group, followed by the isolated PCL-R, and lowest for the combined ACL/PCL-R groups. Significant improvements were observed across all treatment groups in the majority of KOOS subscales between the preoperative, and 1- and 2-year follow-ups. All treatment groups showed the greatest improvements between the preoperative and 2-year follow-ups in the knee-related quality of life (mean improvement: isolated ACL-R, + 28 points; isolated PCL-R, + 23 points; combined ACL/PCL-R, + 21 points) and the function in sport and recreation (mean improvement: isolated ACL-R, + 26 points; isolated PCL-R, + 20 points; combined ACL/PCL-R, + 19 points) subscales.

CONCLUSION

Clinically relevant improvements in knee function can be expected after isolated ACL-R, isolated PCL-R, and combined ACL/PCL-R. Functional improvements were particularly pronounced in the KOOS function in sport and recreation subscale, indicating the importance of knee stability for sports activity. This study facilitates more comprehensive patient education about functional expectations after surgical treatment of isolated and combined ACL and PCL injuries.

LEVEL OF EVIDENCE

Level 2.

Anterior cruciate ligament foot plate anatomy: 3-dimensional and 2-dimensional MRI evaluation with arthroscopy assessment in a subset of patients

OBJECTIVES

ACL reconstruction tunnel location is an important predictor for outcomes after surgery. The aim was to establish 3D and 2D MRI radiological measurements for native ACL tibial footprint that can provide information to facilitate pre-operative planning for anatomical graft placement. The measurements were also correlated in a subset of patients on arthroscopy.

METHODS

Retrospective evaluation of a consecutive series of knee MRIs with both 2D and 3D MR imaging was performed in 101 patients with 43 men and 66 women and ages 39.5 ± 11.9 years. Two measurements were obtained, tibial to ACL and intermeniscal ligament to ACL (T-ACL) and (IM-ACL), respectively. In a cohort of 18 patients who underwent knee arthroscopy, the T-ACL and IML-ACL distances were also determined by an orthopedic surgeon using a standard scale. ICC, Pearson correlation, and Bland-Altman plot were generated.

RESULTS

For readers 1 and 2, the mean differences between 2D and 3D measurements of T-ACL and IM-ACL were 1.17 and 1.03 mm and 0.65 and 0.65 mm, respectively. The 2D measurements of T-ACL and IM-ACL were larger than the 3D measurements for both readers. The inter-reader reliability was excellent on 2D (0.81-0.96) and fair to excellent on 3D MRI (0.59-0.90). The mean arthroscopic IML-ACL was closer to that of 3D MRI compared to 2D MRI. The mean arthroscopic T-ACL was closer to 2D MRI than 3D MRI.

CONCLUSIONS

Both 2D and 3D MRI show inter-reader reliability with small inter-modality mean differences in the measurements from the tibial or inter-meniscal ligament margins.

KEY POINTS

• The mean differences between 2D and 3D measurements of tibia-ACL and intermeniscal ligament-ACL are small (< 1.2 mm). • As compared to arthroscopy, the mean T-ACL and IML-ACL were closer to measurements from 2D and 3D MRI, respectively. • Both 2D and 3D MRI can be reliably used to delineate ACL foot plate anatomy.

Return to work following anterior cruciate ligament reconstruction

BACKGROUND AND PURPOSE

Amongst people of working age, the return to work (RTW) after anterior cruciate ligament (ACL) reconstruction is an important marker of success of surgery. We determined when patients are able to return to work after ACL reconstruction and identified factors that are associated with the timing of RTW.

PATIENTS AND METHODS

We used logistic regression analyses to examine patient-related factors that may be associated with the length of RTW (above vs. below the median 59 days) after arthroscopic ACLR in a large cohort of patients working in the public sector in Finland (n = 803; n = 334 male, n = 469 female; mean age 41 years [SD 8.6]).

RESULTS

The mean length of RTW was 65 days (SD 41). Higher odds ratios (OR) were observed for age groups 40-49 and ≥ 50 years compared with ≤ 30 years old (OR 2.0, 95% confidence interval 1.3-3.1 and 2.0, 1.2-3.4, respectively); for lower level non-manual and manual work compared with higher level non-manual work (3.0, 2.0-4.3 and 4.9, 3.4-7.0, respectively); and for those who had been on sick leave > 30 days in the preceding year (2.0, 1.4-2.9). Sex, comorbid conditions, preceding antidepressant treatment and concomitant procedures were not associated with the length of RTW.

INTERPRETATION

Factors associated with prolonged sick leave beyond the median time of 59 days are higher age, lower occupational status, and preoperative sick leaves.

A Comparison of Inertial Measurement Unit and Motion Capture Measurements of Tibiofemoral Kinematics during Simulated Pivot Landings

Injuries are often associated with rapid body segment movements. We compared Certus motion capture and APDM inertial measurement unit (IMU) measurements of tibiofemoral angle and angular velocity changes during simulated pivot landings (i.e., ~70 ms peak) of nine cadaver knees dissected free of skin, subcutaneous fat, and muscle. Data from a total of 852 trials were compared using the Bland-Altman limits of agreement (LoAs): the Certus system was considered the gold standard measure for the angle change measurements, whereas the IMU was considered the gold standard for angular velocity changes. The results show that, although the mean peak IMU knee joint angle changes were slightly underestimated (2.1° for flexion, 0.2° for internal rotation, and 3.0° for valgus), the LoAs were large, ranging from 35.9% to 49.8%. In the case of the angular velocity changes, Certus had acceptable accuracy in the sagittal plane, with LoAs of ±54.9°/s and ±32.5°/s for the tibia and femur. For these rapid motions, we conclude that, even in the absence of soft tissues, the IMUs could not reliably measure these peak 3D knee angle changes; Certus measurements of peak tibiofemoral angular velocity changes depended on both the magnitude of the velocity and the plane of measurement.

Mechanoreceptor analysis on femoral and tibial site remnant of anterior cruciate ligament injury using immunohistochemistry

Introductions

More than 50% of knee ligament injuries are anterior cruciate ligament (ACL) injuries. The injury can lead to instability and osteochondral damage which in turn leads to early osteoarthritis. ACL remnant contains sensory nerve cells and mechanoreceptors which are useful for reinnervation of the graft and maintaining the knee stability. However, ACL remnant preservation can interfere the visualization during surgery. The number of mechanoreceptors in the ACL remnant of the tibia and femur have to be determined to help the surgeon get better visualization and at the same time preserve the mechanoreceptors in the ACL remnant during reconstruction.

Methods

This study aims to evaluate semi-quantitatively the expression of mechanoreceptors in ACL remnant in the tibia and femur using immunohistochemistry. From January to April 2021, 10 femoral and 10 tibial remnants was obtained from ACL injury patient who received arthroscopic ACL reconstruction. Both of them were analysed using immunohistochemistry with S100 and NFL antibodies. The type of remnant was recorded and the expression of the mechanoreceptor was observed under the microscope.

Results

The most common type of ACL remnant recorded were type 2 (50%), followed by type 1 (40%) and type 4 (10%). There were no significant differences in the expression of mechanoreceptors between femoral remnant and tibial remnant (p = 0.45 and p = 0.134).

Conclusions

No difference in the expression of mechanoreceptors of femoral and tibial ACL remnant. Preservation of both femoral and tibial remnants is important in ACL reconstruction surgery.

•

The most of the ACL remnant recorded are type I.

•

There were no significant differences between femoral and tibial ACL remnants.

•

The remaining mechanoreceptor in the ACL remnant survive a long time.

•

The remaining mechanoreceptor in the ACL remnant had no obvious change in time.

ACL repair for athletes?

Background

The current gold standard treatment for an anterior cruciate ligament (ACL) tear in an athlete is an arthroscopic ACL reconstruction with autografts. This restores the knee stability but is associated with unique complications like graft re-tear, kinesiophobia and graft donor site morbidity. ACL suture repair (ACLSR) is an attractive alternative method of surgical management of this injury.

Current science of ACLSR

The potential advantages of performing a repair are the preservation of native biology and proprioceptive function of ACL, elimination of a graft and preservation of bone stock. The purported benefits are better stability, reduction of kinesiophobia and faster rehabilitation. ACLSR is now performed only for proximal (femoral-sided) tears in the acute phase, when the tissue quality is good and using high-strength nonabsorbable sutures. There are several techniques for performing ACLSR but broadly speaking are either non-augmented, static augmented with suture tape, dynamic augmented or using bio-scaffolds.

Clinical outcome of ACLSR

There is a lot of literature on ACLSRs including case series, cohort studies and randomized controlled trials. The results from these studies are encouraging but mostly pertain to patient reported outcome measures, are in small numbers and in the short-term. The results are also inconsistent across different studies and not specifically performed for the athletic population. Moreover, most of these studies are from the innovator or designer surgeons and groups and have not been independently validated.

Conclusion

Currently, there is insufficient evidence to recommend ACLSR as a preferred method of managing even acute proximal tears in athletes. Improved rates of return to sports, lower retear rate and lesser kinesiophobia needs to be proven in athletes.

Marrow adipose tissue accumulation and dysgenesis of the trabecular bone after anterior cruciate ligament transection and reconstruction in the rat proximal tibial epiphysis

The accumulation of marrow adipose tissue (MAT) is frequently associated with bone loss. Although anterior cruciate ligament (ACL) injury induces bone loss, MAT accumulation after ACL injury has not been evaluated. In addition, no information about changes in MAT after ACL reconstruction is available. In this study, we aimed to examine (1) the effects of ACL transection on the amounts of trabecular bone and MAT present, and (2) whether ACL reconstruction inhibits the changes in the trabecular bone and MAT that are induced by ACL transection. ACL transection alone or with immediate reconstruction was performed on the right knees of rats. Untreated left knees were used as controls. Histomorphological changes in the trabecular bone and MAT in the proximal tibial epiphysis were examined prior to surgery and at one, four, and 12 weeks postsurgery. The trabecular bone area on the untreated side increased in a time-dependent manner. However, after ACL transection, the trabecular bone area did not increase during the experimental period, indicating dysgenesis of the bone (bone loss). Dysgenesis of the trabecular bone after ACL transection was attenuated by ACL reconstruction. MAT accumulation due to adipocyte hyperplasia and hypertrophy had been induced by ACL transection by four weeks postsurgery. This ACL transection-induced MAT accumulation was not prevented by ACL reconstruction. Based on these results, we conclude that (1) dysgenesis of the bone in the proximal tibia following ACL transection is accompanied by MAT accumulation, and (2) ACL reconstruction attenuates dysgenesis of the trabecular bone but cannot prevent MAT accumulation.

Remnant preservation may improve proprioception after anterior cruciate ligament reconstruction

Aim

Our aim was to evaluate the literature investigating proprioception improvement after anterior cruciate ligament reconstruction (ACLR) and test the hypothesis that ACL tibial remnant-preserving reconstruction (ACLR-R) is more beneficial than standard technique (ACLR-S) in terms of postoperative proprioceptive function with various reported tests, including joint position sense (JPS) and threshold to detect passive motion (TTDPM).

Methods

An online search was performed in Embase, MEDLINE/PubMed, Cochrane, SPORTDiscus, and Web of Science databases before 5 October 2020, on the basis of the guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Key terms [(‘ACLR’ or ‘ACL-R’ or ‘anterior cruciate ligament reconstruction’) AND (‘remnant’ or ‘stump’) AND (‘proprioception’ or ‘proprioceptive’)] were used. The Oxford Centre for Evidence-Based Medicine and The McMaster Critical Review Form for Quantitative Studies were used for quality assessment. In total, four articles comparing proprioceptive functions between ACLR-R and ACLR-S were included, two of which were randomized clinical trials rated as level of evidence II, and two were retrospective cohort studies rated as level of evidence III. The outcomes were then compared. Evaluation of proprioception involved joint position sense (JPS) [reproduction of active positioning (RAP) and reproduction of passive positioning (RPP)] and threshold to detect passive motion (TTDPM) tests.

Results

Only four studies were included, with a total of 234 patients (119 ACLR-R patients and 115 ACLR-S patients). High heterogeneity in characteristics and outcome measurements was observed among the studies. Three studies performed sparing technique, and one performed tensioning technique. One study tested RAP and reported better results at an average of 7 months follow-up in ACLR-R (P < 0.05). Three studies tested RPP, one of which measured RPP within 12 months after surgery and reported better results in ACLR-R than in ACLR-S (P < 0.05). The other two studies reported similar results; however, the findings of one study were statistically insignificant. TTDPM was tested in one study, with no statistically significant difference found.

Conclusion

The current literature, although limited, reported proprioception improvement after ACLR-R (compared with ACLR-S) in terms of JPS. However, owing to the heterogeneity of the relevant studies, further research is required to determine remnant preservation effect on knee proprioceptive restoration.

Level of evidence

Level III, systematic review of Level II and III studies.

Anterior cruciate ligament reconstruction with lateral extra-articular tenodesis reduces knee rotation laxity and graft failure rate: A systematic review and meta-analysis

PURPOSE

To determine whether the addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament reconstruction (ACLR) reduces rotational laxity of the knee, and to compare the clinical results of this treatment with those of ACLR alone.

METHODS

PubMed, Embase, and Cochrane Library were searched by two researchers for clinical studies comparing ACLR with and without LET. Studies with only evidence levels I and II and studies in which anterior lateral ligament reconstruction was performed with grafts were excluded. The risk of bias of the studies was assessed using the Cochrane risk-of-bias and modified Downs & Black tools. The outcomes included (1) functional outcomes; (2) knee laxity measures; (3) knee injury osteoarthritis and outcome score; and (4) complications. The outcomes of the two groups were extracted, summarized and compared.

RESULTS

A total of 234 studies were retrieved and 223 were excluded. Eleven clinical studies with 1745 patients were included in our meta-analysis. Compared to the patients who underwent ACLR alone, the patients who underwent ACLR with LET had reduced pivot-shift (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.31 to 0.74, p = 0.0009), and lower graft failure rate (OR 0.34, 95% CI 0.20 to 0.55, p < 0.0001).

CONCLUSION

Compared with ACLR only, ACLR combined with LET can effectively reduce rotation laxity of the knee joint, and reduce the graft failure rate in high-risk patients. However, the effects on the function and activity level of patients cannot be confirmed.

Mechano Growth Factor Accelerates ACL Repair and Improves Cell Mobility of Mechanically Injured Human ACL Fibroblasts by Targeting Rac1-PAK1/2 and RhoA-ROCK1 Pathways

Exceeded mechanical stress leads to a sublethal injury to anterior cruciate ligament (ACL) fibroblasts, and it will hinder cell mobility and ACL regeneration, and even induce osteoarthritis. The mechano growth factor (MGF) could be responsible for mechanical stress and weakening its negative effects on cell physiological behaviors. In this study, effects of MGF on cell mobility and relevant molecules expression in injured ACL fibroblasts were detected. After an injurious mechanical stretch, the analysis carried out, at 0 and 24 h, respectively, showed that the cell area, roundness, migration, and adhesion of ACL fibroblasts were reduced. MGF (10, 100 ng/mL) treatment could improve cell area, roundness and promote cell migration and adhesion capacity compared with the injured group without MGF. Further study indicated that cell mobility-relevant molecules (PAK1/2, Cdc42, Rac1, RhoA, and ROCK1) expression in ACL fibroblasts was down-regulated at 0 or 24 h after injurious stretch (except Rac1 and RhoA at 0 h). Similarly, MGF improved cell mobility-relevant molecule expression, especially the ROCK1 expression level in ACL fibroblasts at 0 or 24 h after injurious stretch. Protein expression of ROCK1 in injured ACL fibroblasts was also reduced and could be recovered by MGF treatment. In a rabbit partial ACL transection (ACLT) model, ACL exhibited poor regenerative capacity in collagen and extracellular matrix (ECM) synthesis after partial ACLT for 2 or 4 weeks, and MGF remarkably accelerated ACL regeneration and restored its mechanical loading capacity after partial ACLT for four weeks. Our findings suggest that MGF weakens the effects of pathological stress on cell mobility of ACL fibroblasts and accelerates ACL repair, and might be applied as a future treatment approach to ACL rupture in the clinic.

Femur-tibia angle and patella-tibia angle: new indicators for diagnosing anterior cruciate ligament tears in magnetic resonance imaging

Background

Femur-tibia angle (FTA) and patella-tibia angle (PTA) are two MRI measurements that reflect the rotation of the knee joint. The purposes of this study were to assess whether FTA and PTA are associated with ACL tear and to explore their roles in ACL tear diagnosis.

Methods

FTA, PTA, ACL angle and anterior tibial subluxation were compared between the two matched groups: ACL tear group and control group (each n = 20). Diagnostic performance was evaluated in a consecutive 120-patient cohort who underwent MR imaging of the knee and subsequently had arthroscopy. Different measurements were assessed by area under the curve (AUC) of receiver operating characteristic (ROC) curve.

Results

FTA and PTA increased significantly in ACL tears group when compared to the control group (4.79 and 7.36 degrees, respectively, p < 0.05). In distinguishing complete ACL tear, ACL angle had the highest AUC of 0.906 while AUC of PTA and FTA were 0.849 and 0.809. The cutoff of FTA was 80 degrees with a sensitivity of 82% and specificity of 68%, while the cutoff of PTA was 91 degrees with a sensitivity of 82% and specificity of 74%. In distinguishing partial ACL tear, FTA and PTA had the highest AUCs of 0.847 and 0.813, respectively. The calculated cutoff of FTA was 84 degrees with a sensitivity of 90% and specificity of 81%, while the cutoff of PTA was 92 degrees with a sensitivity of 80% and specificity of 77%.

Conclusion

FTA and PTA increased when ACL tears and they might be valuable in diagnosing ACL tears, especially in distinguishing partial ACL tear from intact ACL.

Greater proportion of patients report an acceptable symptom state after ACL reconstruction compared with non-surgical treatment: a 10-year follow-up from the Swedish National Knee Ligament Registry

Objectives

To compare the proportion of patients with anterior cruciate ligament (ACL) injury reporting an acceptable symptom state, between non-surgical and surgical treatment during a 10-year follow-up.

Methods

Data were extracted from the Swedish National Knee Ligament Registry. Exceeding the Patient Acceptable Symptom State (PASS) for the Knee injury and Osteoarthritis Outcome Score (KOOS) was the primary outcome. The PASS and KOOS₄ (aggregated KOOS without the activities of daily living (ADL) subscale) were compared cross-sectionally at baseline and 1, 2, 5 and 10 years after ACL injury, where patients treated non-surgically were matched with the maximum number of patients with ACL reconstruction for age, sex and activity at injury.

Results

The non-surgical group consisted of 982 patients, who were each matched against 9 patients treated with ACL reconstruction (n=8,838). A greater proportion of patients treated with ACL reconstruction exceeded the PASS in KOOS pain, ADL, sports and recreation, and quality of life compared with patients treated non-surgically at all follow-ups. With respect to quality of life, significantly more patients undergoing ACL reconstruction achieved a PASS compared with patients receiving non-surgical treatment at all follow-ups except at baseline, with differences ranging between 11% and 25%; 1 year −25.4 (−29.1; −21.7), 2 years −16.9 (−21.2; −12.5), 5 years −11.0 (−16.9; −5.1) and 10 years −24.8 (−36.0; −13.6). The ACL-reconstructed group also reported statistically greater KOOS₄ at all follow-ups.

Conclusion

A greater proportion of patients treated with ACL reconstruction report acceptable knee function, including higher quality of life than patients treated non-surgically at cross-sectional follow-ups up to 10 years after the treatment of an ACL injury.

Anterior Cruciate Ligament Reconstruction Surgery: Creating a Permissive Healing Phenotype in Military Personnel and Civilians for Faster Recovery

Introduction

Anterior cruciate ligament (ACL) rupture in military personnel and civilians can be a devastating injury. A service member is 10 times more likely to suffer an ACL injury than their civilian counterparts, and despite successful surgical stabilization, 4%-35% will develop arthrofibrosis, over 50% will not return to full active duty, and up to 50% will develop post-traumatic osteoarthritis (PTOA) within 15 years. Equally concerning, woman are 2 to 8 times more likely to experience ACL injuries than men, which represents a major knowledge gap.

Materials and Methods

A comprehensive literature search was performed in December 2021 using structured search terms related to prevalence, risk factors, disease progression, and treatment of ACL injury and reconstruction. The literature search was conducted independently by two researchers using PubMed, Cochrane, and Embase databases, with inclusion of articles with military, civilian, and sex relevance, and exclusion of most papers with a publication date greater than 10 years. The resources used for the review reflect the most current data, knowledge, and recommendations associated with research and clinical findings from reliable international sources.

Results

Currently, there is no effective system-based drug therapy that creates a “permissive environment” to reduce synovial and cartilage stress after ACL injury and reconstruction and prevent secondary complications. We argue that progress in this area has been hampered by researchers and clinicians failing to recognize that (1) an ACL injury is a system’s failure that affects the whole joint, (2) the early molecular events define and perpetuate different injury phenotypes, (3) male and female responses may be different and have a molecular basis, (4) the female phenotype continues to be under-represented in basic and clinical research, and (5) the variable outcomes may be perpetuated by the trauma of surgery itself. The early molecular events after ACL injury are characterized by an overexpression of joint inflammation, immune dysfunction, and trauma-induced synovial stress. We are developing an upstream adenosine, lidocaine, and magnesium therapy to blunt these early molecular events and expedite healing with less arthrofibrosis and early PTOA complications.

Conclusions

ACL injuries continue to be a major concern among military personnel and civilians and represent a significant loss in command readiness and quality of life. The lack of predictability in outcomes after ACL repair or reconstruction underscores the need for new joint protection therapies. The male–female disparity requires urgent investigation.

Is Peroneus longus autograft a better alternative to the Hamstring autograft for anterior cruciate ligament reconstruction? – A randomised control study

Purpose

The anterior cruciate ligament in the knee is commonly prone to injuries. Reconstruction of this ligament with hamstring tendon has been time-tested but peroneus longus autograft is also gaining popularity. However, very limited literature is available comparing the two grafts. This study aims to compare the functional outcome and donor site morbidity between hamstrings and peroneus longus autograft in anterior cruciate ligament reconstruction.

Methods

A prospective randomised study was conducted on 45 patients, who underwent anterior cruciate ligament reconstruction. Patients were assigned into Hamstring group and the Peroneus longus group. Functional outcome was assessed using Lysholm score and Modified Cincinnati scores for the knee joint and American Orthopedics Foot and Ankle Scoring for ankle joint. Donor site morbidity was assessed by measuring flexion and extension strength of the knee and plantar flexion and eversion strength of the ankle by handheld dynamometer preoperatively and postoperatively at 6 months and 1 year follow up.

Results

Functional outcome of the knee showed significant improvement in peroneus longus group (p-value 0.002) compared to hamstring group. Even though there was minimal reduction in functional outcome of the ankle at 6 months follow-up in peroneus longus group, it improved at one year follow-up. While assessing the donor site morbidity at the knee joint, knee flexion strength showed improvement in the group (p-value 0.02) but reduced in the hamstring group where the hamstring tendon was harvested. Knee extension strength in the hamstring group scored marginally better than the peroneus longus group, which was not statistically significant (p-value 0.5).

Conclusion

Autologous peroneus longus tendon can be used as a graft of choice in anterior cruciate ligament reconstruction which showed promising results without compromising on the ankle function. Its usage as an alternative source of the graft may be more useful in multi-ligament injuries of the knee joint.

Testing a Quaternion Conversion Method to Determine Human Three-Dimensional Tibiofemoral Angles During an In Vitro Simulated Jump Landing

Lower limb joint kinematics have been measured in laboratory settings using fixed camera-based motion capture systems; however, recently inertial measurement units (IMUs) have been developed as an alternative. The purpose of this study was to test a quaternion conversion (QC) method for calculating the three orthogonal knee angles during the high velocities associated with a jump landing using commercially available IMUs. Nine cadaveric knee specimens were instrumented with APDM Opal IMUs to measure knee kinematics in one-legged 3-4× bodyweight simulated jump landings, four of which were used in establishing the parameters (training) for the new method and five for validation (testing). We compared the angles obtained from the QC method to those obtained from a commercially available sensor and algorithm (APDM Opal) with those calculated from an active marker motion capture system. Results showed a significant difference between both IMU methods and the motion capture data in the majority of orthogonal angles (p < 0.01), though the differences between the QC method and Certus system in the testing set for flexion and rotation angles were smaller than the APDM Opal algorithm, indicating an improvement. Additionally, in all three directions, both the limits of agreement and root-mean-square error between the QC method and the motion capture system were smaller than between the commercial algorithm and the motion capture.

Emergency Department Visits Within 90 Days of Anterior Cruciate Ligament Reconstruction

Background:

Emergency department (ED) visits after orthopaedic surgery such as anterior cruciate ligament reconstruction (ACLR) affect patients and health care systems and should be better understood.

Purpose:

To determine the incidence, predictors, and reasons for ED visits within 90 days after ACLR.

Study Design:

Descriptive epidemiologic study.

Methods:

Patients who had undergone ACLR between 2010 and 2020 were identified in a national database, and 90-day ED visits, readmissions, risk factors, and primary diagnoses for visits were determined. One-year postoperative data were used to establish baseline weekly ED visits for the cohort. Patient age, sex, Elixhauser comorbidity index, region of the country (Northeast, Midwest, West, South), and insurance coverage (Medicare, Medicaid, and commercial) were extracted, and these variables were compared using univariate analysis and multivariate logistic regression.

Results:

Out of 81,179 patients, ED visits were identified for 6764 (8.3%), and readmissions were identified for 592 (0.7%). Overall, 5300 patients had 1 ED visit, 1020 patients had 2 visits, 275 patients had 3 visits, and 169 patients had ≥4 or more visits; visits occurred within 2 weeks of surgery 38% of the time. Notably, weekly visits returned to baseline at week 3. Independent predictors of ED utilization from multivariate analysis were insurance type (relative to commercial insurance: Medicaid [odds ratio [OR], 2.41; 95% CI, 2.23-2.60] and Medicare [OR, 1.38; 95% CI, 1.19-1.60]), higher Elixhauser comorbidity index (per 2-point increase: OR, 2.24; 95% CI, 2.18-2.29), younger age (per 10-year decrease: OR, 1.23; 95% CI, 1.21-1.24), female sex (OR, 1.05; 95% CI, 1.02-1.08), and region of the country (relative to the West: Midwest [OR, 1.33; 95% CI, 1.26-1.39], Northeast [OR, 1.24; 95% CI, 1.18-1.30], and South [OR, 1.17; 95% CI, 1.12-1.23]). In the first 2 weeks, 67.5% of ED visits were for issues involving the surgical site, most commonly surgical-site pain (29% of all visits). In the total 90-day period, 39.4% of visits involved the surgical site.

Conclusion:

Within 90 days of ACLR, >8% of patients visited the ED, while 0.7% were readmitted. ED visits increased in the first 2 postoperative weeks and returned to baseline rates around week 3. Within the first 2 weeks, two-thirds of visits involved the surgical site. Younger patients, patients with greater comorbidity burden, those in certain regions of the country, and those with Medicaid had greater odds of ED utilization.

Bilateral muscle atrophy after anterior cruciate ligament reconstruction in rats: Protective effects of anti-inflammatory drug celecoxib

BACKGROUND

Muscle atrophy after anterior cruciate ligament (ACL) reconstruction occurs bilaterally and contributes to a decrease in muscle strength. However, effective treatment strategies for ACL reconstruction-induced muscle atrophy have not been established. We examined the effects of anti-inflammatory drug on muscle atrophy after ACL reconstruction.

MATERIALS AND METHODS

Rats were divided into groups according to treatment received: untreated control (n = 4), arthrotomy (n = 6), ACL transection (n = 7), ACL reconstruction (n = 8), and ACL reconstruction plus anti-inflammatory drug celecoxib (CBX; 50 mg/kg/day) administration (n = 8). At one-week post-surgery, the muscle fiber cross-sectional area (CSA) in the rectus femoris (RF) and semitendinosus (ST) was measured to assess muscle atrophy. In addition, we examined joint swelling and serum C‑reactive protein (CRP) levels to assess local and systemic inflammation, respectively.

RESULTS

Each additional procedure (i.e., arthrotomy, ACL transection, and ACL reconstruction) gradually decreased the muscle fiber CSAs in the RF and ST on both operated and contralateral sides. The degree of muscle fiber atrophy on the operated side was larger than that detected on the contralateral side. Moreover, ACL reconstruction induced joint swelling on the operated side and tended to increase serum CRP levels. CBX lessened the RF atrophy on both sides and was associated with less joint swelling and a smaller increase CRP level; however, it did not affect ST atrophy on either side.

CONCLUSIONS

Anti-inflammatory treatments after ACL reconstruction may be effective in lessening muscle atrophy in the quadriceps, but not in the hamstrings.

Knee Injury Detection Using Deep Learning on MRI Studies: A Systematic Review

The improved treatment of knee injuries critically relies on having an accurate and cost-effective detection. In recent years, deep-learning-based approaches have monopolized knee injury detection in MRI studies. The aim of this paper is to present the findings of a systematic literature review of knee (anterior cruciate ligament, meniscus, and cartilage) injury detection papers using deep learning. The systematic review was carried out following the PRISMA guidelines on several databases, including PubMed, Cochrane Library, EMBASE, and Google Scholar. Appropriate metrics were chosen to interpret the results. The prediction accuracy of the deep-learning models for the identification of knee injuries ranged from 72.5-100%. Deep learning has the potential to act at par with human-level performance in decision-making tasks related to the MRI-based diagnosis of knee injuries. The limitations of the present deep-learning approaches include data imbalance, model generalizability across different centers, verification bias, lack of related classification studies with more than two classes, and ground-truth subjectivity. There are several possible avenues of further exploration of deep learning for improving MRI-based knee injury diagnosis. Explainability and lightweightness of the deployed deep-learning systems are expected to become crucial enablers for their widespread use in clinical practice.

Osteoarthritis Progression after ACL Reconstruction Was Significantly Higher Than That of the Healthy Contralateral Knees: Long-Term Follow Up Study of Mean 16.4 Years

Background: This study aimed to assess long-term progression of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction in athletes compared to the healthy contralateral side. Methods: The study included 15 patients and 30 knees with a mean age of 40 years (range, 35–46) years, none of whom had had revision surgery or an injury to the contralateral side. The mean follow-up period was 16.4 years (range, 13–22). Clinical and radiographic assessment included the Tegner activity scale (TAS), International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Kellgren and Lawrence (KL) grade. The long-term results of the injured knees were compared with the status of the healthy contralateral side and compared with previously published mid-term results of the same cohort of patients. Results: Patients generally remained clinically asymptomatic or mildly symptomatic at final follow-up, which is reflected by a KOOS pain score of 33 points (maximum 36 points) and an IKDC total subjective score of 87% (maximum 100%). There was a significant difference between mid-term and final follow-up in terms of the function score of the IKDC subjective questionnaire (p = 0.031), compartment findings and donor site morbidity of the IKDC functional examination (both p = 0.034), and the total KOOS score (p = 0.047). The KL score indicated significant progression of OA from mid-term to final follow-up in the injured knees (p = 0.004) and healthy contralateral knees (p = 0.014). Mean OA grades of the injured knees were significantly higher compared with the healthy contralateral side (p = 0.006) at final follow-up, and two patients showed moderate to severe signs of OA in the injured knee. Conclusions: Although most patients remained clinically asymptomatic or mildly symptomatic, long-term progression of OA after isolated ACL reconstruction in athletes was significantly higher compared with the healthy contralateral knee.

Force Production Patterns of Muscles Surrounding Knee During Running and Cutting Maneuvers: A Musculoskeletal Modeling Approach

OBJECTIVES The purpose of this study was to investigate the force production patterns of individual muscles surrounding the knee during running (RUN) and cutting (CUT) tasks.METHODS Thirteen women (24.2±3.5 yrs, 162.8±6.0 cm, 55.3±6.2 kg) performed a series of running and cutting tasks. Running and cutting motions were recorded using a motion capture system and ground reaction force (GRF) was recorded using a force plate. Three-dimensional knee angle, ground reaction force, and knee joint moment were calculated using Visual3D software. OpenSim musculoskeletal modeling software was used to calculate the force of individual muscles including the medial hamstring, biceps femoris long head, biceps femoris short head, rectus femoris, vastus medialis, vastus lateralis, gastrocnemius medialis, and gastrocnemius lateralis. All data were analyzed for loading response (or weight acceptance), mid-stance, and final push-off periods, respectively and were compared between two tasks.RESULTS At loading response: external rotation angle, medial and vertical GRFs, and valgus moment for the CUT task were greater than those of the RUN task. Compared to the RUN task, the CUT task showed: 1) an increase in lateral hamstring muscle force at weight acceptance, 2) a decrease in hamstring muscle force and an increase in medial vastus muscle force at mid-stance, and 3) an increase in lateral gastrocnemius muscle force at final push-off.CONCLUSIONS Selective force production patterns of muscles surrounding the knee seem to offset the external load caused by the cutting motion. We anticipate that our results will provide basic data for future training programs designed to prevent noncontact knee injuries.

Post-traumatic Osteoarthritis in Rabbits Following Traumatic Injury and Surgical Reconstruction of the Knee

Post-traumatic osteoarthritis (PTOA) of the knee is often attributed to anterior cruciate ligament (ACL) and meniscus injury. The development of PTOA, however, does not seem to depend on whether or not the damaged ACL is reconstructed. There has been a need to develop animal models to study the mechanisms of PTOA following reconstruction of a traumatized knee. Eighteen rabbits underwent closed-joint trauma to produce ACL rupture and meniscus damage. Then, for the first time, the traumatized knee was surgically repaired in this animal model. Upon euthanasia at 1-, 3- or 6-month post-trauma, joint stability, cartilage morphology and mechanical properties, as well as histology of the cartilage and subchondral bone were evaluated. Trauma-induced knee injury involved 72% mid-substance ACL rupture, 28% partial ACL tear and 56% concurrent medial meniscal damage. ACL reconstruction effectively restored joint stability by reducing joint laxity to a level similar to that in the contralateral intact knee. Compared to their contralateral controls, reconstructed limbs showed osteoarthritic changes to the cartilage and subchondral bone as early as 1-month post-trauma. The degeneration progressed over time up to 6-month. Overall, the medial compartments had more tissue damage than their corresponding lateral counterparts. Damage patterns to the ACL, the frequency of observed concurrent meniscal injury, and reductions in cartilage integrity and health were consistent with clinical observations of human patients who undergo ACL injury and reconstruction. Thus, we believe the combined closed-joint injury and surgical repair lapine model of PTOA, being first-ever and clinically relevant, shows promise to evaluate well-targeted therapeutics and other interventions for this chronic disease.

Tackling the Challenges of Graft Healing After Anterior Cruciate Ligament Reconstruction-Thinking From the Endpoint

Anterior cruciate ligament (ACL) tear is common in sports and accidents, and accounts for over 50% of all knee injuries. ACL reconstruction (ACLR) is commonly indicated to restore the knee stability, prevent anterior–posterior translation, and reduce the risk of developing post-traumatic osteoarthritis. However, the outcome of biological graft healing is not satisfactory with graft failure after ACLR. Tendon graft-to-bone tunnel healing and graft mid-substance remodeling are two key challenges of biological graft healing after ACLR. Mounting evidence supports excessive inflammation due to ACL injury and ACLR, and tendon graft-to-bone tunnel motion negatively influences these two key processes. To tackle the problem of biological graft healing, we believe that an inductive approach should be adopted, starting from the endpoint that we expected after ACLR, even though the results may not be achievable at present, followed by developing clinically practical strategies to achieve this ultimate goal. We believe that mineralization of tunnel graft and ligamentization of graft mid-substance to restore the ultrastructure and anatomy of the original ACL are the ultimate targets of ACLR. Hence, strategies that are osteoinductive, angiogenic, or anti-inflammatory should drive graft healing toward the targets. This paper reviews pre-clinical and clinical literature supporting this claim and the role of inflammation in negatively influencing graft healing. The practical considerations when developing a biological therapy to promote ACLR for future clinical translation are also discussed.

Arabic Version of the Short Anterior Cruciate Ligament-Return to Sport After Injury Scale: Translation, Cross-cultural Adaptation, and Validation

Background:

The short version of the Anterior Cruciate Ligament–Return to Sport After Injury (ACL-RSI) scale is a self-reported questionnaire developed to assess the psychological readiness of patients to return to sports after ACL reconstruction (ACLR).

Purpose:

To translate, cross-culturally adapt, and validate the short version of the ACL-RSI scale into the Arabic language (ACL-RSI-Ar).

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

The original short version of the ACL-RSI scale was forward and backward translated, cross-culturally adapted, and validated following international standardized guidelines. Sixty patients who participated in sports activities and underwent ACLR completed the ACL-RSI-Ar, the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, and Knee injury and Osteoarthritis Outcome Score (KOOS) scales. To assess test-retest reliability, 34 participants completed the ACL-RSI-Ar scale twice. Statistical tests were conducted to test the internal consistency, reliability, and construct and discriminant validity of the ACL-RSI-Ar scale.

Results:

The ACL-RSI-Ar showed adequate internal consistency (Cronbach alpha = 0.734) and excellent test-retest reliability (intraclass correlation coefficient, 0.871). The ACL-RSI-Ar was strongly correlated with the IKDC (Spearman ρ = 0.515, P < .001) and weakly to strongly correlated with all KOOS subscales (Spearman ρ = 0.247-0.590, P < .05). Patients who returned to sports had significantly higher scores on the ACL-RSI-Ar scale when compared with those who did not return to sports (P = .001).

Conclusion:

The short ACL-RSI-Ar scale, as translated, was internally consistent, reliable, and valid for evaluating psychological readiness to return to sports after ACLR in Arabic-speaking patients.

Low to moderate risk of nerve damage during peroneus longus tendon autograft harvest

PURPOSE

This study aims to evaluate the proximity of the tendon stripper to both the peroneal and sural nerves during peroneus longus tendon (PLT) autograft harvesting.

METHODS

Ten fresh-frozen human cadaveric lower extremities were used to harvest a full-thickness PLT autograft using a standard closed blunt-ended tendon stripper. The distance to the sural nerve from the PLT (at 0, 1, 2 and 3 cm proximal to lateral malleolus (LM), and the distance to the peroneal nerve and its branches from the end of the tendon stripper were measured by two separate observers using ImageJ software.

RESULTS

The average distance from the PLT to the sural nerve increased significantly from 0 to 2 cm proximal to LM. The average distance to the sural nerve at the LM was 4.9 ± 1.5 mm and increased to 10.8 ± 2.4 mm (2 cm proximal to LM). The average distance from the tendon stripper to the deep peroneal nerve was 52.9 ± 11.4 mm. The average distance to the PLT branch of peroneal nerve was 29.3 ± 4.2 mm. The superficial peroneal nerve, which coursed parallel and deep to the tendon stripper, was on average 5.2 ± 0.7 mm from the end of the stripper. No transection injuries of the nerves were observed in any of the ten legs after harvesting.

CONCLUSION

This cadaver study found during a full-thickness PLT harvest, the distances between the tendon stripper and the nerves were greater than 5 mm with an initial incision at 2 cm proximal to LM which is recommended.

Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation

Clinical evaluation and management of anterior cruciate ligament (ACL) injury is one of the most widely researched topics in orthopedic sports medicine, giving providers ample data on which to base their practices. The ACL is also the most commonly treated knee ligament. This study reports on current topics and research in clinical management of ACL injury, starting with evaluation, operative versus nonoperative management, and considerations in unique populations. Discussion of graft selection and associated procedures follows. Areas of uncertainty, rehabilitation, and prevention are the final topics before a reflection on the current state of ACL research and clinical management of ACL injury. Level of evidence V.

Energy Absorption Contribution Deficits in Participants Following Anterior Cruciate Ligament Reconstruction: Implications for Second Anterior Cruciate Ligament Injury

Context: Lower-extremity loading patterns change after anterior cruciate ligament reconstruction (ACLR). However, there is limited research regarding energy absorption contribution (EAC) of athletes following ACLR who reinjure their ACL and those who do not. EAC can be utilized as a measure of joint loading during tasks. Design: Cross-sectional study. Methods: Three groups of individuals (13 in each group) with matched age, sex, height, weight, and sports were enrolled. Data were collected at time of return-to-sport testing for the 2 ACLR groups. An 8-camera 3D motion capture system with a sampling rate of 120 Hz and 2 force plates capturing at 1200 Hz were used to capture joint motions in all 3 planes during a double-limb jump landing. Results: Participants in the ACLR no reinjury and ACLR reinjury groups had significantly greater hip EAC (55.8 [21.5] and 56.7 [21.2]) compared with healthy controls (19.5 [11.1]), P < .001 and P < .001, respectively. The ACLR no reinjury and ACLR reinjury groups had significantly lower knee EAC (24.6 [22.7] and 27.4 [20.8]) compared with healthy controls (57.0 [12.2]), P < .001 and P < .001, respectively. However, the ACLR reinjury group had significantly lower ankle EAC (15.9 [4.6]) than healthy controls (23.5 [6.6]), whereas there was no statistical difference between the ACLR no reinjury group (19.7 [7.8]) and healthy controls. Conclusions: Athletes who had a second ACL injury after ACLR, and those without second ACL injury, appear to have similar hip, knee, and ankle joint loading of the surgical limb at return-to-sport testing. Nevertheless, joint loading patterns were significantly different from healthy controls. The study suggests that EAC as a measure of joint loading during a double-limb jump landing at time of return to sport may not be a strong predictor for second injury following ACLR.

Development and Test of a Decision Aid for Shared Decision Making in Patients with Anterior Cruciate Ligament Injury

Background. Patients with anterior crucial ligament injury are faced with a choice between surgery or nonsurgical treatment with intensive rehabilitation. Patients must be involved in the decision making to choose a treatment that meets their individual values, lifestyle, and conditions. The aim of the study was to describe, develop, and evaluate a patient decision aid to support shared decision making. Methods. The development of a patient decision aid was based on international criteria, current literature, and former patients’ experiences and suggestions on how to optimize the decision-making process. The patient decision aid was evaluated by the SDM-Q9 questionnaire and semistructured interviews with patients and doctors. Results. On a scale from 0 to 5, patients experienced a high degree of shared decision making in their treatment decision both before (score 4.3) and after (score 4.3) implementation of the patient decision aid (P = .72). From interviews, patients expressed that they found the patient decision aid very useful. Reflection time was especially important for some patients. Doctors reported that the patient decision aid improved shared decision making by supporting the dialogue clarifying patients’ values concerning issues important for treatment choices. Conclusion. A systematic process involving patients with an anterior crucial ligament injury was successfully used to develop a patient decision aid for treatment options. No statistically significant difference in the SDM-Q9 score was found presumably caused by the ceiling effect. However, patients experienced the decision aid as very useful when making treatment decisions, and doctors reported that it improved the dialogue clarifying patients’ values important for the treatment options. The developing process and patient decision aid can be used as inspiration in similar situations to increase shared decision making in treatment choices.

Return to preinjury sports after anterior cruciate ligament reconstruction is predicted by five independent factors

PURPOSE

To determine factors that predict return to the same frequency and type of sports participation with similar activity demands as before injury.

METHODS

Individuals 1 to 5 years after primary ACL reconstruction completed a comprehensive survey related to sports participation and activity before injury and after surgery. Patient characteristics, injury variables, and surgical variables were extracted from the medical record. Return to preinjury sports (RTPS) was defined as: "Returning to the same or more demanding type of sports participation, at the same or greater frequency with the same or better Marx Activity Score as before injury." Variables were compared between individuals that achieved comprehensive RTPS and those that did not with univariate and multivariate logistic regression models.

RESULTS

Two-hundred and fifty-one patients (mean age 26.1 years, SD 9.9) completed the survey at an average of 3.4 years (SD 1.3) after ACL reconstruction. The overall rate of RTPS was 48.6%. Patients were more likely to RTPS if they were younger than 19 years old (OR = 4.07; 95%CI 2.21-7.50; p < 0.01) or if they were competitive athletes (OR = 2.07; 95%CI 1.24-3.46; p = 0.01). Patients were less likely to RTPS if surgery occurred more than 3 months after injury (OR = 0.31, 95%CI 0.17-0.58; p < 0.01), if there was a concomitant cartilage lesion (OR = 0.38; 95%CI 0.21-0.70; p < 0.01), and if cartilage surgery was performed (OR = 0.17; 95%CI 0.04-0.80; p = 0.02).

CONCLUSION

Five variables best predicted RTPS including age at time of surgery. Only time from injury to surgery is a potentially modifiable factor to improve RTPS; however, the reasons for which patients delayed surgery may also contribute to them not returning to sports. Regardless, younger patients, those that partake in sports on a competitive level, those that undergo surgery sooner, or do not have a cartilage injury or require cartilage surgery are more likely to return to pre-injury sports participation.

LEVEL OF EVIDENCE

III.

The Clinical Efficacy and Risk Factors after Revision and Reconstruction of Anterior Cruciate Ligament

The aim of this study was to study the clinical efficacy and prognostic factors after revision and reconstruction of anterior cruciate ligament. All the patients who underwent the first revision of anterior cruciate ligament (ACL) reconstruction in the department of sports medicine from January 2001 to December 2015 were collected. The demographic information, the first revision and reconstruction information of ACL, and the information during the first ACL reconstruction were collected. A total of 335 cases were included. Lysholm score, Tegner activity score, and IKDC subjective score at the last follow-up were significantly higher than those before operation. Compared with graft failure caused by sports injury, the postoperative scores of patients with revision due to life accidents or initial reconstruction techniques were significantly lower (P < 0.05). The postoperative Lysholm score of patients with femoral canal drilling through the tibial canal was lower than that of patients with anterior internal approach. The postoperative IKDC score of patients who underwent medial meniscus suture at the same time was higher than that of patients without meniscus combined injury. ACL revision can improve the stability and function of knee joint. Compared with the revision caused by life accident or technical reasons of primary reconstruction surgery, the patients with graft failure caused by sports injury have better postoperative recovery. Medial meniscus suture and anterior internal approach drilling of the femoral bone canal have a statistically protective effect on the clinical function after ACL revision.

The Natural History of Medial Meniscal Tears in the ACL Deficient and ACL Reconstructed Rat Knee

OBJECTIVE

The process of anterior cruciate ligament (ACL) injury-induced meniscal tear formation is not fully understood. Clinical studies have shown that ACL reconstruction (ACLR) reduces the development of secondary meniscal tears, but it is difficult to gain insight into the protective effects of ACLR from clinical studies alone. Using rat ACL transection (ACLT) and ACLR models, we aimed to reveal (1) the formation process of meniscal tears secondary to ACLT and (2) the protective effects of ACLR on secondary meniscal tears.

DESIGN

ACLT surgery alone or with ACLR was performed on the knees of rats. Histomorphological and histopathological changes were examined in the posteromedial region of the meniscus in intact rats and in rats that received ACLT or ACLR up to 12 weeks postsurgery. In addition, anterior-posterior joint laxity was measured using the universal testing machine to evaluate the effects of ACLT and ACLR on joint laxity.

RESULTS

AAnterior-posterior laxity was significantly increased by ACLT compared to the intact knee. This ACLT-induced joint laxity was partially but significantly reduced by ACLR. Meniscal proliferation and hyaline cartilage-like tissue formation were detected in the medial meniscus at 4 weeks post-ACLT. At 12 weeks post-ACLT, hyaline cartilage-like tissue was replaced by ossicles and meniscal tears were observed. These ACLT-induced abnormalities were attenuated by ACLR.

CONCLUSIONS

Our results suggest that ACLT-induced joint laxity induces secondary medial meniscal tears through meniscal proliferation and ossicle formation via endochondral ossification. Joint re-stabilization by ACLR suppresses meniscal proliferation and ossicle formation and consequently prevents secondary meniscal tears.

The top 100 highly cited articles on anterior cruciate ligament from 2000 to 2019: A bibliometric and visualized analysis

INTRODUCTION

Bibliometrics can trace the overall research trend in a specific field. To our knowledge, there has been no comprehensive bibliometric analysis of all anterior cruciate ligament (ACL) research from 2000-2019. We provided a bibliometric and visualized analysis of the top 100 highly-cited articles on ACL indexed by the Web of Science (WoS) to provide researchers with the present research status and the potential direction of ACL research.

HYPOTHESIS

A bibliometric and visualized analysis of the top 100 highly-cited articles on ACL may identify the research trends, popular journals, core countries, influential institutions and authors in this field.

MATERIAL AND METHODS

We obtained data from the WoS Core Collection on February 20, 2020. Qualitative and quantitative analyses were conducted based on the WoS. Collaboration and keywords analysis was performed using the VOSviewer software.

RESULTS

The top 100 highly-cited literatures included 88 articles and 12 reviews. The average total citations was 325 (ranging 197 to 1,423). The article with 1432 citations published by Hewett TE et al. in 2005 was the most influential reference. Sixteen cohort studies and 14 clinical randomized controlled trials were included among the 100 literatures. Twenty-three journals published the top 100 literatures. The American Journal of Sports Medicine published 44 papers with 15,665 citations. The USA published 65 highly-cited articles. The University of Pittsburgh published 13 literatures with 3,966 citations. Hewett TE published 11 papers with 4,806 citations. Extensive collaboration existed worldwide. Reconstruction, kinematics, posterolateral bundle, in-situ forces, neuromuscular control, long-term follow-up, tunnel placement, and prevention were the most common keywords.

DISCUSSION

In this field, The American Journal of Sports Medicine was the most influential journal. The USA was the most productive and influential country. Researchers and institutions from North America and Europe contributed the most. Regarding the treatments for ACL injuries, we do need well-reported and good-quality enduring randomized trials to assess the effectiveness and cost-effectiveness of current treatments.

LEVEL OF PROOF

IV; retrospective analysis.

The ankle syndesmosis pivot shift "Are we reviving the ACL story?"

In recent literature, there is a growing interest for the high ankle sprain with emerging evidence on biomechanical behavior, function, injury, and treatment. Interpretation of emerging publications on the distal tibiofibular syndesmosis may raise questions about striking similarities with the anterior cruciate ligament function and pivot-shift mechanism of injury in the knee. This editorial note puts to question whether identical entities, a continuum or separate injuries are faced by contemplating on the mechanism of injury, diagnostics, treatment, and outcome.

Anatomic double-bundle anterior cruciate ligament reconstruction could not achieve sufficient control of pivot-shift when accompanying tibial tunnel coalition

PURPOSE

To evaluate the effect of tibial tunnel coalition on knee rotatory laxity and clinical outcomes after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Forty-one patients who underwent anatomic DB ACL reconstruction were included prospectively. Three-dimensional computed tomography of the knee joint was obtained at approximately 1 year postoperatively to determine if tunnel coalition occurred. After excluding seven cases of femoral tunnel coalition, two groups were established based on the existence of a tibial tunnel coalition. The pivot-shift test was quantitatively evaluated on the basis of tibial acceleration preoperatively and at 1 year postoperatively. Two subjective scores, the International Knee Documentation Committee (IKDC) subjective and Lysholm scores, were also collected. The pivot-shift measurement and subjective scores were compared between the ACL-reconstructed knees with and without tibial tunnel coalition. The independent t test, Pearson's chi-square test, and Student t tests were used in data analysis.

RESULTS

Twenty-one knees had tibial tunnel coalition (group C), whereas 13 knees did not have tunnel coalition(group N). Pivot-shift was significantly diminished postoperatively in both groups on the basis of the clinical examination and quantitative evaluations (p < 0.05). However, there was a small but significant difference in tibial acceleration demonstrating larger pivot-shift in group C (1.0 ± 0.6 m/s²) than in group N (0.5 ± 0.3 m/s², p < 0.05). No significant difference was observed in the IKDC subjective and Lysholm scores (both n.s.).

CONCLUSION

When the tibial tunnel coalition occurs after DB ACL reconstruction, knee rotatory laxity may not be restored in ACL-reconstructed knees, as expected in those without tunnel coalition. It is recommended that two tibial tunnels should be created separately when performing DB-ACL reconstruction to achieve better control of rotatory knee laxity.

LEVEL OF EVIDENCE

III.

ACL Study Group survey reveals the evolution of anterior cruciate ligament reconstruction graft choice over the past three decades

PURPOSE

Anterior cruciate ligament reconstruction (ACLR) aims to restore knee function and stability, allowing patients to return to the activities they enjoy and minimize further injury to the meniscus and cartilage and their ultimate progression to osteoarthritis. This study aims to present the evolution of graft choice over the last three decades according to members of the ACL Study Group (SG).

METHODS

Prior to the January 2020 ACL SG biannual meeting, a survey was administered consisting of 87 questions and 16 categories, including ACLR graft choice. A similar questionnaire has been administered prior to each meeting and survey results from the past 14 meetings (1992 through 2020, excluding 1994) are included in this work. Survey responses are reported as frequencies in percentages to quantify changes in practice over the surgery period.

RESULTS

In 1992, the most frequent graft choice for primary ACLR was bone-patellar tendon-bone (BTB) autograft, at nearly 90%. Hamstring tendon (HT) autografts have increased in popularity, currently over 50%, followed by just under 40% BTB autograft. Recently, quadriceps tendon (QT) autograft has increased in popularity since 2014.

CONCLUSION

Autograft (HT, BTB, QT) is an overwhelming favorite for primary ACLR over allograft. The preference for HT autograft increased over the study period relative to BTB autograft, with QT autograft gaining in popularity in recent years. Graft selection should be individualized for each patient and understanding the global trends in graft choice can help orthopaedic surgeons discuss graft options with their patients and determine the appropriate graft for each case.

LEVEL OF EVIDENCE

Level V, Expert Opinion.

Effects of Each Phase of Anterior Cruciate Ligament Reconstruction Surgery on Joint Contracture in Rats

BACKGROUND

Although anterior cruciate ligament reconstruction surgery is known to cause joint contracture, the mechanisms of this process are unknown. We aimed to assess the effects of transection of this ligament and each phase of reconstruction surgery on contracture formation.

MATERIALS AND METHODS

Rats were divided into groups according to treatment received: sham (arthrotomy), ligament transection, ligament transection plus bone drilling, and ligament reconstruction. Surgery was performed on the right knee. Untreated left knees in the sham group were used as controls.

RESULTS

At 7 and 28 d post-surgery, range of motion before myotomy, mainly representing myogenic contracture, was restricted in the sham and ligament transection groups, and more so in the bone drilling and reconstruction groups. Restricted range of motion after myotomy, representing arthrogenic contracture, was detected at both timepoints in the bone drilling and reconstruction groups, but not in the sham or ligament transection groups. At 3 d post-surgery, although a large blood clot was observed in all three treatment groups, only the bone drilling and reconstruction groups showed significant joint swelling. At 7 d post-surgery, inflammatory-cell infiltration into the joint capsule was most apparent in the bone drilling and reconstruction groups, and joint capsule fibrosis was also most apparent in these groups at 7 and 28 d post-surgery.

CONCLUSIONS

Our results suggest that (1) myogenic contracture after anterior cruciate ligament reconstruction is caused by arthrotomy and aggravated by bone drilling, and (2) arthrogenic contracture is mostly due to bone drilling, which triggers an inflammation-fibrosis cascade.

Graft Selection in Contemporary Anterior Cruciate Ligament Reconstruction

In the last decade, there have been significant advances in our understanding of anterior cruciate ligament (ACL) reconstruction. Recent prospective cohort studies have identified risk factors for ACL reconstruction graft failure such as younger patient age, increased activity level, nonanatomic tunnel placement, and the use of allograft. Among these, the most easily modifiable risk factor is graft choice. Given that the surgeon's recommendation has been shown to be one of the most important factors behind patients' graft choice, it is critical that the operating surgeon have a thorough understanding of all the ACL graft options available to choose the graft that would be most suitable for the patient's personalized reconstruction (i.e., patient's anatomy, sport, level of competition, age, risk factors for failure, and graft used in previous ACL surgery). The purpose of this review is to provide an up-to-date understanding of the current ACL graft reconstruction options. The indications, advantages, and disadvantages of the different ACL reconstruction graft options available will be discussed.

A Prediction Model for Primary Anterior Cruciate Ligament Injury Using Artificial Intelligence

Background

Supervised machine learning models in artificial intelligence (AI) have been increasingly used to predict different types of events. However, their use in orthopaedic surgery has been limited.

Hypothesis

It was hypothesized that supervised learning techniques could be used to build a mathematical model to predict primary anterior cruciate ligament (ACL) injuries using a set of morphological features of the knee.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Included were 50 adults who had undergone primary ACL reconstruction between 2008 and 2015. All patients were between 18 and 40 years of age at the time of surgery. Patients with a previous ACL injury, multiligament knee injury, previous ACL reconstruction, history of ACL revision surgery, complete meniscectomy, infection, missing data, and associated fracture were excluded. We also identified 50 sex-matched controls who had not sustained an ACL injury. For all participants, we used the preoperative magnetic resonance images to measure the anteroposterior lengths of the medial and lateral tibial plateaus as well as the lateral and medial bone slope (LBS and MBS), lateral and medial meniscal height (LMH and MMH), and lateral and medial meniscal slope (LMS and MMS). The AI predictor was created using Matlab R2019b. A Gaussian naïve Bayes model was selected to create the predictor.

Results

Patients in the ACL injury group had a significantly increased posterior LBS (7.0° ± 4.7° vs 3.9° ± 5.4°; P = .008) and LMS (-1.7° ± 4.8° vs -4.0° ± 4.2°; P = .002) and a lower MMH (5.5 ± 0.1 vs 6.1 ± 0.1 mm; P = .006) and LMH (6.9 ± 0.1 vs 7.6 ± 0.1 mm; P = .001). The AI model selected LBS and MBS as the best possible predictive combination, achieving 70% validation accuracy and 92% testing accuracy.

Conclusion

A prediction model for primary ACL injury, created using machine learning techniques, achieved a >90% testing accuracy. Compared with patients who did not sustain an ACL injury, patients with torn ACLs had an increased posterior LBS and LMS and a lower MMH and LMH.

Assessing implementation, limited efficacy, and acceptability of the BEAST tool: A rehabilitation and return-to-sport decision tool for nonprofessional athletes with anterior cruciate ligament reconstruction

OBJECTIVES

To assess the implementation, limited efficacy, and acceptability of the BEAST (better and safer return to sport) tool - a rehabilitation and return-to-sport (RTS) decision tool after anterior cruciate ligament reconstruction (ACLR) in nonprofessional athletes.

DESIGN

Prospective cohort.

PARTICIPANTS

43 nonprofessional pivoting sport athletes with ACLR.

MAIN OUTCOME

Clinician- and athlete-experienced implementation challenges (implementation), changes in quadriceps power, side hop and triple hop performance from 6 to 8 months after ACLR (limited efficacy), athletes' beliefs about the individual rehabilitation and RTS plans produced by the BEAST tool (acceptability).

RESULTS

The BEAST tool was developed and then implemented as planned for 39/43 (91%) athletes. Hop and quadriceps power performance improved significantly, with the largest improvement in involved quadriceps power (standardised response mean 1.4, 95% CI:1.1-1.8). Athletes believed the rehabilitation and RTS plan would facilitate RTS (8.2 [SD: 2.0]) and reduce injury risk (8.3 [SD: 1.2]; 0 = not likely at all, 10 = extremely likely).

CONCLUSION

The BEAST tool was implemented with few challenges and adjustments were rarely necessary. Athletes had large improvements in quadriceps power and hop performance on the involved leg. Athletes believed that the individual rehabilitation and RTS plans produced by the tool would facilitate RTS and reduce injury risk.

The correlation between posterior tibial slope and dynamic anterior tibial translation and dynamic range of tibial rotation

Purpose

The amount of passive anterior tibial translation (ATT) is known to be correlated to the amount of posterior tibial slope (PTS) in both anterior cruciate ligament-deficient and reconstructed knees. Slope-altering osteotomies are advised when graft failure after anterior cruciate ligament (ACL) reconstruction occurs in the presence of high PTS. This recommendation is based on studies neglecting the influence of muscle activation. On the other hand, if dynamic range of tibial rotation (rTR) is related to the amount of PTS, a “simple” anterior closing-wedge osteotomy might not be sufficient to control for tibial rotation. The purpose of this study was to evaluate the correlation between the amount of PTS and dynamic ATT and tibial rotation during high demanding activities, both before and after ACL reconstruction. We hypothesized that both ATT and rTR are strongly correlated to the amount of PTS.

Methods

Ten subjects were studied both within three months after ACL injury and one year after ACL reconstruction. Dynamic ATT and dynamic rTR were measured using a motion-capture system during level walking, during a single-leg hop for distance and during a side jump. Both medial and lateral PTS were measured on MRI. A difference between medial and lateral PTS was calculated and referred to as Δ PTS. Spearman’s correlation coefficients were calculated for the correlation between medial PTS, lateral PTS and Δ PTS and ATT and between medial PTS, lateral PTS and Δ PTS and rTR.

Results

Little (if any) to weak correlations were found between medial, lateral and Δ PTS and dynamic ATT both before and after ACL reconstruction. On the other hand, a moderate-to-strong correlation was found between medial PTS, lateral PTS and Δ PTS and dynamic rTR one year after ACL reconstruction.

Conclusion

During high-demand tasks, dynamic ATT is not correlated to PTS. A compensation mechanism may be responsible for the difference between passive and dynamic ATT in terms of the correlation to PTS. A moderate-to-strong correlation between amount of PTS and rTR indicates that such a compensation mechanism may fall short in correcting for rTR. These findings warrant prudence in the use of a pure anterior closing wedge osteotomy in ACL reconstruction.

Trial registration

Netherlands Trial Register, Trial 7686. Registered 16 April 2016—Retrospectively registered.

Level of evidence

Level 2, prospective cohort study

Peroneus longus tendon autograft has functional outcomes comparable to hamstring tendon autograft for anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

This review aimed to assess whether peroneus longus tendon (PLT) autograft would have comparable functional outcomes and graft survival rates when compared to hamstring tendon (HT) autograft for anterior cruciate ligament (ACL) reconstruction.

METHODS

PubMed, Web of Science, Cochrane Library, Ovid (MEDICINE), and EMBASE databases were queried for original articles from clinical studies including the keywords: ACL reconstruction and PLT autograft. Studies comparing PLT autograft versus HT autograft were included in this analysis and the following data were extracted from studies meeting the inclusion criteria: graft diameter, functional outcomes (Tegner activity scale, Lysholm score, and International Knee Documentation Committee (IKDC) subjective score), knee laxity (Lachman test), and complications (donor site pain or paresthesia, graft failure). Besides, the American Orthopaedic Foot and Ankle Society (AOFAS) scale and the Foot and Ankle Disability Index (FADI) pre-operation and at last follow-up were also compared among patients using PLT autograft. Meta-analysis was applied using Review Manager 5.3 and p < 0.05 was considered statistically significant.

RESULTS

Twenty-three studies including 925 patients with ACL reconstruction met inclusion criteria. Of these, 5 studies included a direct comparison of PLT autograft (164 patients) versus HT autograft (174 patients). No significant difference was observed between PLT and HT autografts for Tegner activity scale, Lachman test, donor site pain, or graft failure. However, PLT groups demonstrated better Lysholm score (mean difference between PLT and HT groups, 1.55; 95% CI 0.20-2.89; p = 0.02) and IKDC subjective score (mean difference between PLT and HT groups, 3.24; 95% CI 0.29-6.19; p = 0.03). No difference of FADI was found (n.s.) but AOFAS was slightly decreased at last post-operative follow-up for patients with PLT autograft compared with pre-operative scores (mean difference of 0.31, 95% CI 0.07-0.54, p = 0.01).

CONCLUSION

PLT autograft demonstrated comparable functional outcomes and graft survival rates compared with HT autograft for ACL reconstruction. However, a slight decrease in AOFAS score should be considered during surgical planning. Hence, the PLT is a suitable autograft harvested outside the knee for ACL reconstruction to avoid the complication of quadriceps-hamstring imbalance which can occur when harvesting autografts from the knee.

LEVEL OF EVIDENCE

Level II.

Reconstruction for Chronic ACL Tears with or without Anterolateral Structure Augmentation in Patients at High Risk for Clinical Failure: A Randomized Clinical Trial

BACKGROUND

The purpose of this trial was to determine whether anterior cruciate ligament reconstruction (ACLR) with anterolateral structure augmentation (ALSA) would result in better clinical outcomes in patients with a high risk of clinical failure.

METHODS

From February 2017 to June 2018, 120 young, active adults with chronic anterior cruciate ligament injury and high risk of clinical failure were randomized. The patients were followed for >2 years, with 5 being lost to follow-up and 1 being withdrawn from the study. Clinical characteristics, operative findings, and postoperative clinical outcomes were analyzed.

RESULTS

The analysis included data from 114 patients, including 95 men and 19 women with a mean age (and standard deviation) of 30.1 ± 6.7 years in the ACLR group and 30.1 ± 6.4 years in the ALSA group. The rate of clinical failure was 20.4% (11 of 54 patients) and 3.3% (2 of 60 patients) in the ACLR and ALSA groups, respectively (difference, 17.1%; 95% confidence interval [CI], 5.3% to 29.8%; p = 0.007). Significantly higher rates of return to the preinjury level of sports (48.3% versus 27.8%; difference, 20.5%; 95% CI, 2.7% to 36.6%; p = 0.024) and to a competitive level of play (63.3% versus 42.6%; difference, 22.3%; 95% CI, 4.1% to 38.8%; p = 0.027) was found in the ALSA group.

CONCLUSIONS

Compared with isolated ACLR, combined ACLR and ALSA resulted in a reduction in persistent rotatory laxity and higher rates of return to preinjury and competitive levels of play at 2 years of follow-up in the population studied. Our study suggests that patients with high risk of clinical failure appear to be candidates for the ALSA approach.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Stem cell therapies in tendon-bone healing

Tendon-bone insertion injuries such as rotator cuff and anterior cruciate ligament injuries are currently highly common and severe. The key method of treating this kind of injury is the reconstruction operation. The success of this reconstructive process depends on the ability of the graft to incorporate into the bone. Recently, there has been substantial discussion about how to enhance the integration of tendon and bone through biological methods. Stem cells like bone marrow mesenchymal stem cells (MSCs), tendon stem/progenitor cells, synovium-derived MSCs, adipose-derived stem cells, or periosteum-derived periosteal stem cells can self-regenerate and potentially differentiate into different cell types, which have been widely used in tissue repair and regeneration. Thus, we concentrate in this review on the current circumstances of tendon-bone healing using stem cell therapy.