Development of new cartilage lesions after ACL reconstruction is associated with abnormal knee rotation

Knee biomechanics during walking in individuals with anterior cruciate ligament repair: The role of a custom 3D-printed knee brace

BACKGROUND

Anterior cruciate ligament (ACL) injuries frequently lead to altered gait biomechanics and muscle activation patterns, increasing the risk of osteoarthritis. Knee braces are commonly used to address these issues although a lack of consensus remains regarding their clinical benefits. The most recent 3D-printed braces, lighter and personalized, could improve rehabilitation.

OBJECTIVES

To evaluate the effect of a novel custom-made 3D-printed knee brace (Provoke™) in individuals after unilateral ACL reconstruction during walking. The brace incorporates an asymmetrical hinge system aimed at stabilizing the knee joint while minimizing compensatory movements.

METHODS

Fourteen participants with unilateral ACL reconstruction wore the Provoke™ brace while walking at comfortable and fast paces. Knee kinematics and kinetics and muscular activity (rectus femoris, vastus medialis, and semitendinosus) were assessed with and without the brace. Nonparametric paired t tests were used to assess the biomechanical effect of the brace.

RESULTS AND CONCLUSIONS

The Provoke™ brace improved knee kinematics, facilitating a more neutral knee position by reducing valgus angles (-1.95°) and increasing flexion angles (+1.14°). In addition, it enhanced muscle activation, particularly of the rectus femoris, suggesting improved quadriceps function. Overall, the Provoke™ brace effectively improves knee function and reduces muscle imbalances in individuals undergoing ACL reconstruction. It may help prevent further injury and reduce the risk of post-traumatic osteoarthritis development. The long-term effects of brace use in ACL rehabilitation must be investigated.

Reliability and changes in knee cartilage T2 relaxation time from 6 to 24 months after anatomic anterior cruciate ligament reconstruction

The objectives of this study were to evaluate the reliability of cartilage T2 relaxation time measurements and to identify focal changes in T2 relaxation on the affected knee from 6 to 24 months after anatomic anterior cruciate ligament reconstruction (ACLR). Data from 41 patients who received anatomic ACLR were analyzed. A bilateral 3.0-T MRI was acquired 6 and 24 months after ACLR. T2 relaxation time was measured in subregions of the femoral condyle and the tibial plateau. The root-mean-square coefficient of variation (RMSCV) was calculated to evaluate the reliability of T2 relaxation time in the contralateral knee. Subregion changes in the affected knee T2 relaxation time were identified using the contralateral knee as a reference. The superficial and full thickness layers of the central and inner regions showed good reliability. Conversely, the outer regions on the femoral side and regions in the deep layers showed poor reliability. T2 relaxation time increased in only 3 regions on the affected knee when controlling for changes in the contralateral knee, while changes in T2 relaxation time were identified in 14 regions when not using the contralateral knee as a reference. In conclusion, evaluation of cartilage degeneration by T2 relaxation time after ACLR is most reliable for central and inner cartilage regions. Cartilage degeneration occurs in the central and outer regions of the lateral femoral condyle from 6 to 24 months after anatomic ACLR.

No difference in osteoarthritis, but less graft failures after 5 years, comparing anatomic double-bundle to anatomic single-bundle ACL reconstruction

PURPOSE

The purpose of this study was to compare the incidence of knee osteoarthritis (OA) between the anatomic single-bundle (SB) and anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction technique after 5-year follow-up (FU). Secondary objectives were to compare patient-reported outcome measures (PROMs), clinical examination, activity level, functional tests and graft failures between the two groups.

METHODS

The study was a secondary analysis after 5-year FU of a randomized controlled trial (RCT) (Clinical Trials NCT01033188). One hundred and twenty patients between 18 and 40 years were randomized to either anatomic SB or anatomic DB reconstruction. The Kellgren-Lawrence (KL) classification grade ≥2 and the Osteoarthritis Research Society International (OARSI) atlas criteria score ≥2 were used for defining OA. Additionally, PROMs were obtained and clinical examinations of the knees were performed. Finally, the number of patients experiencing graft failure in each group was recorded.

RESULTS

Radiographic imaging was performed in 39 patients in the SB group and in 37 patients in the DB group. Four patients (10%) in the SB group and two (5%) in the DB group developed osteoarthritis according to the KL classification (p = 0.28). Five (13%) in the SB group and three (8%) in the DB group developed osteoarthritis according to the OARSI atlas criteria (p = 0.59; difference 5.0% [95% confidence interval, CI: -0.10 to 0.20]). There were no significant differences in the PROMs, clinical examinations, activity levels, or functional tests when comparing the two groups. Of initially 62 SB patients, 14 (23%) experienced graft failure compared to 4 (7%) of the 58 DB patients (p = 0.015; difference 0.016 [95% CI: 0.03-0.29]).

CONCLUSION

At 5-year FU, there were no significant differences in the incidence of OA, PROMS, or other clinical findings comparing the anatomic DB to anatomic SB ACL reconstructed patients. There were fewer graft failures among patients treated with anatomic DB ACL reconstruction.

LEVEL OF EVIDENCE

II.

Chronic ACLD Knees with Early Developmental Cartilage Lesions Exhibited Increased Posterior Tibial Translation during Level Walking

OBJECTIVE

Early articular cartilage lesion (CL) is a vital sign in the onset of posttraumatic knee osteoarthritis (PTOA) in patients with anterior cruciate ligament deficiency (ACLD). Researchers have suggested that altered kinematics could accelerate CLs and, therefore, lead to the onset of PTOA. However, little is known about whether specific knee kinematics exist that lead to early CL in chronic ACLD knees. Level walking is the most frequent and relevant in vivo activity, which greatly impacts knee health. We hypothesized that the knee kinematics during level walking in chronic ACLD knees with early tibiofemoral CL would significantly differ from those of chronic ACLD knees without early tibiofemoral CL.

METHODS

Thirty patients with a chronic ACLD history, including 18 subjects with CLs and 12 subjects without CLs, and 35 healthy control subjects were recruited for the study from July 2020 to August 2022. The knee kinematic data during level walking were collected using a three-dimensional motion analysis system. The kinematic differences between groups were compared using statistical parametric mapping with one dimension for One-Way ANOVA. The cartilage statuses of the ACLD knees were assessed via MRI examination. The CLs distribution of subjects was evaluated using a modified Noyes scale and analyzed by chi-square tests.

RESULTS

ACLD knees with CLs had significantly greater posterior tibial translation (7.7-8.0mm, 12%-18% gait cycle GC, p = 0.014) compared to ACLD knees without CLs during level walking. ACLD knees with CLs had greater posterior tibial translation (4.6-5.5mm, 0%-23% GC, p < 0.001; 5.8-8.0mm, 86%-100% GC, p < 0.001) than healthy controls during level walking. In the group of ACLD knees with CLs, CL is mainly located in the back of the tibia plateau and front of load bearing area of the medial femoral condyle (p < 0.05).

CONCLUSION

Chronic anterior cruciate ligament deficient knees with cartilage lesions have increased posterior tibial translation compared to anterior cruciate ligament deficient knees without cartilage lesions and healthy subjects. The posterior tibial translation may play an important role in knee cartilage degeneration in ACLD knees. The increased posterior tibial translation and cartilage lesion characteristics may improve our understanding of the role of knee kinematics in cartilage degeneration and could be a helpful potential reference for anterior cruciate ligament deficient therapy, such as physical training to improve abnormal kinematic behavior.

Knee Kinematic Patterns and Early Cartilage Lesion Characteristics in Patients with Anterior Cruciate Ligament Reconstruction

Specific knee kinematic alterations have been theorized to correlate with the progression of cartilage degeneration, and therefore, post-traumatic osteoarthritis in patients with anterior cruciate ligament reconstruction (ACLR). However, how specific knee kinematic alterations contribute to knee joint cartilage degenerations remains to be unclear. To solve this problem, we hypothesized that there are specific cartilage-degenerating kinematic gait patterns that could be supported by the specific areas of cartilage lesions in ACLR knees. Thirty patients with unilateral ACLR knees and 30 healthy controls were recruited for the study. The kinematic differences between the ACLR knees and the healthy control knees during the stance phase were calculated to identify the kinematic patterns. Cartilage lesion distribution characteristics were acquired for patients with ACLR knees to validate the kinematic patterns using magnetic resonance images. Two kinematic patterns were modeled, i.e., sagittal (increased flexion angle and posterior tibial translation) and coronal (increased lateral tibial translation and abduction angle) kinematic patterns. For the sagittal pattern, the cartilage lesion distributions showed that there were more cartilage lesions (CLs) in the superoposterior regions than the posterior regions in the femoral condyles (p = 0.001), and more CLs in the posterior regions than the middle regions in the tibial plateau (p < 0.001). For the coronal pattern, the cartilage lesion distributions showed that there were more CLs in the lateral compartments near the tibial spine than the medial compartments near the tibial spine (tibial sides, p = 0.005 and femoral sides, p = 0.290). To conclude, the cartilage degeneration distribution evidence largely supports that the two kinematic patterns may contribute to cartilage degeneration in ACLR knees. These findings may provide a potential strategy of delaying early cartilage degeneration in ACLR knees by using motion (kinematic) pattern modification or training. However, investigations should be conducted on the actual effects of this potential strategy.

Risk factors of cartilage lesion after anterior cruciate ligament reconstruction

Anterior cruciate ligament injury is the most common sports injury in orthopaedics, which can adversely affect knee joint function and exercise of patients. Using arthroscopy to reconstruct the anterior cruciate ligament has become the first choice for treating anterior cruciate ligament rupture. However, different degrees of articular cartilage injury of the knee can be observed in patients after anterior cruciate ligament reconstruction. More importantly, the articular cartilage injury after anterior cruciate ligament reconstruction indicates that it will develop into osteoarthritis in the long term. It is of great significance to fully understand the factors that lead to the occurrence and development of cartilage injury. This article reviews the effects of surgical methods, meniscus status, different grafts, time from injury to surgical intervention, postoperative knee joint stability, postoperative rehabilitation, knee joint anatomical factors, and demographic characteristics of patients on articular cartilage degeneration after anterior cruciate ligament reconstruction. The present review provides insights into the anterior cruciate ligament reconstruction, which can be used to investigate new treatment strategies to delay and prevent the progress of osteoarthritis. At the same time, it provides a holistic understanding of the influence of multiple factors on cartilage lesions after anterior cruciate ligament reconstruction.

ACLD patients exhibit additional knee kinematic asymmetries at the speed level of healthy subjects

Anterior cruciate ligament deficiency (ACLD) patients tend to walk slowly but try to catch up with the speed level of healthy subjects daily. Exploring the effects of the walking speed level of healthy subjects on the ACLD patients' knee kinematics is important to improving non-operative treatments and delaying the progression of posttraumatic knee osteoarthritis. This study aimed to explore whether healthy controls' walking speed level leads to additional knee kinematic asymmetries in patients with ACLD. 27 ACLD patients and 29 healthy controls were recruited for the study. The ACLD patients walked at two levels of walking speed, including self-selected and healthy controls' walking speed levels. A three-dimensional gait analysis system was used to collect their knee kinematic data. ACLD patients exhibited more kinematic asymmetries when walking at healthy controls' walking speed level than at their self-selected speeds. The kinematic asymmetries included increased posterior tibial translation (4.6 mm) and anteroposterior tibial ROM (3.9 mm), abduction angle (1.5°), and distal tibial translation (3.2 mm) asymmetries (p < 0.05). Our findings are meaningful for developing non-operative treatment strategies for patients with ACLD. To get fewer knee kinematic asymmetries, self-selected walking speed could be suggested for patients with ACLD daily rather than the speed levels of healthy subjects.

Adjustable-loop implants are non-inferior to fixed-loop implants for femoral fixation in anterior cruciate ligament reconstruction

PURPOSE

Button implants with an adjustable-loop device (ALD) are often used in anterior cruciate ligament reconstruction (ACLR). Clinical research comparing ALDs with fixed-loop devices (FLD) has mainly been conducted in small patient populations with short follow-up times. To determine whether ALDs are safe to use in ACLR, a non-inferiority study with a large sample population and a long follow-up period would be beneficial. This study compared ALDs with FLDs to determine non-inferior revision surgery rates, knee stability, and patient-reported outcomes (PROM) in ACLRs.

METHODS

This non-inferiority register-based cohort study was conducted using data from the Danish Knee Ligament Reconstruction Registry (DKRR). A total of 12,723 patients > 15 years of age with primary ACLR using hamstring tendon autografts and either an FLD or ALD for femoral fixation were included: 9719 patients were in the FLD group, and 3014 patients were in the ALD group. The primary outcome was revision ACLR with a non-inferiority margin for ALDs at 4% at the 2-year follow-up. The secondary outcomes were anterior and rotatory knee stability and PROMs based on the Knee Injury and Osteoarthritis Outcome Score (KOOS) at the 1-year follow-up.

RESULTS

The crude cumulative revision rates in ALD implants at 2 and 5 years were 2.1% (95% CI 1.62-2.68) and 5.0% (95% CI 4.22-5.96), respectively. In the FLD group, the rates were 2.2% (95% CI 1.89-2.48) at 2 years and 4.7% (95% CI 4.31-5.20) at 5 years. The 1-year side-to-side differences were 0.97 mm (95% CI 0.90-1.03) in the ALD group and 1.45 mm (95% CI 1.41-1.49) in the FLD group. In the FLD group, 13% had a positive pivot shift, and in the ALD group, 6% had a positive pivot shift. There were no differences in KOOS.

CONCLUSION

ALDs were non-inferior to FLDs regarding revision rates, knee stability, and patient-reported outcomes. Based on this conclusion, ALDs are safe to use for femoral fixation in ACLR.

LEVEL OF EVIDENCE

III.

Clinical Significance of the Static and Dynamic Q-angle

Q-angle represents the resultant force vector of the quadriceps and patellar tendons acting on the patella. An increased Q-angle has been considered a risk factor for many disorders and injuries. This literature review challenges the clinical value of static Q-angle and recommends a more dynamic movement evaluation for making clinical decisions. Although there are many articles about static Q-angle, few have assessed the value of dynamic Q-angle. We searched Scopus and PubMed (until September 2021) to identify and summarize English-language articles evaluating static and dynamic Q-angle, including articles for dynamic knee valgus (DKV) and frontal plane projection angle. We also used textbooks and articles from references to related articles. Although static Q-angle measurement is used systematically in clinical practice for critical clinical decisions, its interpretation and clinical translation present fundamental and intractable limitations. To date, it is acceptable that mechanisms that cause patellofemoral pain and athletic injuries have a stronger correlation with dynamic loading conditions. Dynamic Q-angle has the following three dynamic elements: frontal plane (hip adduction, knee abduction), transverse plane (hip internal rotation and tibia external rotation), and patella behavior. Measuring one out of three elements (frontal plane) illustrates only one-third of this concept. Static Q-angle lacks biomechanical meaning and utility for dynamic activities. Although DKV is accompanied by hip and tibia rotation, it remains a frontal plane measurement, which provides no information about the transverse plane and patella movement. However, given the acceptable reliability and the better differentiation capability, DKV assessment is recommended in clinical practice.