Tibiofemoral contact and alignment in patients with anterior cruciate ligament rupture treated nonoperatively versus reconstruction : an upright, open MRI study

Osteoarthritic Tibiofemoral Joint Contact Characteristics During Weightbearing With Arch-Supported and Standalone Lateral Wedge Insoles

Imbalanced joint load distribution across the tibiofemoral surface is a risk factor for osteoarthritic changes to this joint. Lateral wedge insoles, with and without arch support, are a form of biomechanical intervention that can redistribute tibiofemoral joint load, as estimated by external measures of knee load. The objective of this study was to examine the effect of these insoles on the internal joint contact characteristics of osteoarthritic knees during weightbearing. Fifteen adults with tibiofemoral osteoarthritis underwent magnetic resonance imaging of the affected knee, while standing under 3 insole conditions: flat control, lateral wedge alone, and lateral wedge with arch support. Images were processed, and the surface area and centroid location of joint contact were quantified separately for the medial and lateral tibiofemoral compartments. Medial contact surface area was increased with the 2 lateral wedge conditions compared with the control (P ≤ .012). A more anterior contact centroid was observed in the medial compartment in the lateral wedge with arch support compared with the lateral wedge alone (P = .009). Significant changes in lateral compartment joint contact outcomes were not observed. These findings represent early insights into how loading at the tibiofemoral interface may be altered by lateral wedge insoles as a potential intervention for knee osteoarthritis.

Association of the Coronal Lateral Collateral Ligament Sign in ACL-Deficient Knees With Greater Anterior Tibial Translation and Femorotibial Rotation in Adults and Adolescents

Background

The coronal lateral collateral ligament (LCL) sign (the entire LCL being seen in 1 coronal slice on a magnetic resonance imaging [MRI] scan), is a new secondary sign of anterior cruciate ligament (ACL) tear.

Purpose

To (1) evaluate the coronal LCL sign in adults with ACL tears and (2) compare the magnitude of the MRI scan parameters between adolescent and adult ACL-deficient knees with positive coronal LCL signs.

Study Design

Cross-sectional study; Level of evidence: 3.

Methods

We retrospectively reviewed patients who underwent ACL reconstruction between February 1, 2013, and May 31, 2021, and divided them into adolescent (10-18 years) and adult (>18 years) groups. Tibial translation, femorotibial rotation, and presence of the coronal LCL sign were evaluated using MRI. The static femorotibial position parameters were also compared between positive and negative coronal LCL sign groups. Independent Student t tests were used to identify statistically significant differences for continuous variables, whereas the categorical variables were compared using the chi-square test.

Results

A total of 65 adolescents and 300 adults with ACL tears were identified. The coronal LCL sign was present in a similar percentage of adolescents and adults with ACL tears (57% vs 58%; P = .873). The anterior tibial translation (ATT) in patients with positive coronal LCL signs (adolescents, 7.9 ± 3.4 mm; adults, 6.6 ± 3.5 mm) was significantly greater compared with those with negative signs (adolescents, 1.5 ± 2.6 mm, P < .001; adults, 2.3 ± 4.2 mm, P < .001). Femorotibial rotation was also statistically greater in positive coronal LCL sign groups (adolescents, 6.4°± 5.6°; adults, 7.0°± 5.0°) compared with negative sign groups (adolescents, 0.7°± 4.7°, P < .001; adults, 3.5°± 4.2°, P < .001).

Conclusion

The occurrence of the coronal LCL sign on MRI scans was comparable between adolescents and adults with ACL-deficient knees. The presence of the LCL sign was associated with a greater ATT and femorotibial rotation in both adolescents and adults with ACL tears.

The challenge of evaluating our surgical procedures

Cite this article: Bone Joint J 2023;105-B(11):1133–1134.

Anterior cruciate ligament injuries in female athletes

The anterior cruciate ligament (ACL) is frequently injured in elite athletes, with females up to eight times more likely to suffer an ACL tear than males. Biomechanical and hormonal factors have been thoroughly investigated; however, there remain unknown factors that need investigation. The mechanism of injury differs between males and females, and anatomical differences contribute significantly to the increased risk in females. Hormonal factors, both endogenous and exogenous, play a role in ACL laxity and may modify the risk of injury. However, data are still limited, and research involving oral contraceptives is potentially associated with methodological and ethical problems. Such characteristics can also influence the outcome after ACL reconstruction, with higher failure rates in females linked to a smaller diameter of the graft, especially in athletes aged < 21 years. The addition of a lateral extra-articular tenodesis can improve the outcomes after ACL reconstruction and reduce the risk of failure, and it should be routinely considered in young elite athletes. Sex-specific environmental differences can also contribute to the increased risk of injury, with more limited access to and availablility of advanced training facilities for female athletes. In addition, football kits are designed for male players, and increased attention should be focused on improving the quality of pitches, as female leagues usually play the day after male leagues. The kit, including boots, the length of studs, and the footballs themselves, should be tailored to the needs and body shapes of female athletes. Specific physiotherapy programmes and training protocols have yielded remarkable results in reducing the risk of injury, and these should be extended to school-age athletes. Finally, psychological factors should not be overlooked, with females' greater fear of re-injury and lack of confidence in their knee compromising their return to sport after ACL injury. Both intrinsic and extrinsic factors should be recognized and addressed to optimize the training programmes which are designed to prevent injury, and improve our understanding of these injuries.

Delaying anterior cruciate ligament reconstruction increases the rate and severity of medial chondral injuries

Aims

The aim of this study was to evaluate the association between chondral injury and interval from anterior cruciate ligament (ACL) tear to surgical reconstruction (ACLr).

Methods

Between January 2012 and January 2022, 1,840 consecutive ACLrs were performed and included in a single-centre retrospective cohort. Exclusion criteria were partial tears, multiligament knee injuries, prior ipsilateral knee surgery, concomitant unicompartmental knee arthroplasty or high tibial osteotomy, ACL agenesis, and unknown date of tear. A total of 1,317 patients were included in the final analysis, with a median age of 29 years (interquartile range (IQR) 23 to 38). The median preoperative Tegner Activity Score (TAS) was 6 (IQR 6 to 7). Patients were categorized into four groups according to the delay to ACLr: < three months (427; 32%), three to six months (388; 29%), > six to 12 months (248; 19%), and > 12 months (254; 19%). Chondral injury was assessed during arthroscopy using the International Cartilage Regeneration and Joint Preservation Society classification, and its association with delay to ACLr was analyzed using multivariable analysis.

Results

In the medial compartment, delaying ACLr for more than 12 months was associated with an increased rate (odds ratio (OR) 1.93 (95% confidence interval (CI) 1.27 to 2.95); p = 0.002) and severity (OR 1.23 (95% CI 1.08 to 1.40); p = 0.002) of chondral injuries, compared with < three months, with no association in patients aged > 50 years old. No association was found for shorter delays, but the overall dose-effect analysis was significant for the rate (p = 0.015) and severity (p = 0.026) of medial chondral injuries. Increased TAS was associated with a significantly reduced rate (OR 0.88 (95% CI 0.78 to 0.99); p = 0.036) and severity (OR 0.96 (95% CI 0.92 to 0.99); p = 0.017) of medial chondral injuries. In the lateral compartment, no association was found between delay and chondral injuries.

Conclusion

Delay was associated with an increased rate and severity of medial chondral injuries in a dose-effect fashion, in particular for delays > 12 months. Younger patients seem to be at higher risk of chondral injury when delaying surgery. The timing of ACLr should be optimally reduced in this population.

Effect of secretory leucocyte protease inhibitor on early tendon-to-bone healing after anterior cruciate ligament reconstruction in a rat model

AIMS

To verify whether secretory leucocyte protease inhibitor (SLPI) can promote early tendon-to-bone healing after anterior cruciate ligament (ACL) reconstruction.

METHODS

In vitro: the mobility of the rat bone mesenchymal stem cells (BMSCs) treated with SLPI was evaluated by scratch assay. Then the expression levels of osteogenic differentiation-related genes were analyzed by real-time quantitative PCR (qPCR) to determine the osteogenic effect of SLPI on BMSCs. In vivo: a rat model of ACL reconstruction was used to verify the effect of SLPI on tendon-to-bone healing. All the animals of the SLPI group and the negative control (NC) group were euthanized for histological evaluation, micro-CT scanning, and biomechanical testing.

RESULTS

SLPI improved the migration ability of BMSCs and upregulated the expression of genes related to osteogenic differentiation of BMSCs in vitro. In vivo, the SLPI group had higher histological scores at the tendon-bone interface by histological evaluation. Micro-CT showed more new bone formation and bone ingrowth around the grafted tendon in the SLPI group. Evaluation of the healing strength of the tendon-bone connection showed that the SLPI group had a higher maximum failure force and stiffness.

CONCLUSION

SLPI can effectively promote early tendon-to-bone healing after ACL reconstruction via enhancing the migration and osteogenic differentiation of BMSCs. Cite this article: Bone Joint Res 2022;11(7):503-512.