Enxerto ideal para ligamento cruzado anterior: correlação em ressonância magnética entre LCA, isquiotibiais, tendão patelar e tendão quadríceps

How safe are partial squats after the anterior cruciate ligament reconstruction? A finite element analysis

BACKGROUND

Partial squats are a part of many rehabilitation programs. Progress to deeper squats can only be performed through the partial squat position. However, squats safety, onset time, and rational depth are still controversial. Most previous studies have not considered the influence of posterior tibial slope (PTS) and anterolateral ligament (ALL) on the stress on the knee anatomical elements in partial squats.

METHODS

We have created the new comprehensive knee computer models, which considered muscle exertions while weight bearing 75, 100, 125, and 150 kg in partial squats, included the ALL, two variants of PTS (5° and 13.9°), and two variants of anterior cruciate ligament (ACL) (a native 6 mm double-bundle ACL and an 8 mm single-bundle ACL graft). Using the finite element analysis, we have analyzed stresses in 14 anatomical elements in each model in partial squats (55° knee flexion and 10° anterior tibia tilt).

RESULTS

PTS change from 5° to 13.9° in a partial squat increases stress 1.2-1.3 times on the native ACL and 1.3-1.4 times on the ALL. In the case of single-bundle ACL reconstruction, PTS growth from 5° to 13.9° results in stress increasing 1.2-1.3 times on the graft and 1.3-1.4 times on the ALL. Thus, increased PTS is a significant risk factor, especially in the early postoperative period. Weight-bearing predictably increases stress on the ACL, ALL, and other joint elements proportional to the weight growth. Patients with thinner grafts after the ACL reconstruction may already reach the risk level for graft rupture in a single load in partial squatting if they weigh 125 kg or more. The risk rises with increasing PTS angle or the patient's weight. Because of the reduction of the graft strength by six weeks after surgery by 27%, partial squats in six weeks are associated with forces that may exceed the maximal ACL load even in patients with 75 kg of weight without additional load.

CONCLUSION

In the early postoperative period, partial squats can put the ACL graft at risk of failure. This risk is proportional to the patient's weight and PTS angle, and inversely proportional to the graft thickness. The choice of physical therapy strategies after ACL reconstruction, exercises, and their initiation timing is complex and cannot be standardized for all patients. Factors like the thickness of the graft, the method of fixation, the patient's weight, the ALL insufficiency, the PTS angle, and the patient's goals in the short and long term should be considered when planning the rehabilitation program.

Effect of demographic features on morphometric variables of the knee joint: Sample of a 20 to 40-year-old Turkish population

This study aimed to investigate the relationship between body mass index (BMI), age, and sex and morphological risk factors that may cause internal knee injuries. The magnetic resonance images of 728 participants who met the inclusion criteria and had a mean age of 34.4 ± 6.8 years were analyzed retrospectively. Demographic differences were analyzed by measuring 17 morphological parameters known to be associated with internal knee injuries. Men had a higher anterior cruciate ligament length (ACLL), anterior cruciate ligament width, (ACLW) lateral femoral condylar width (LFCW), medial femoral condylar width (MFCW), lateral femoral condylar depth (LFCD), distal femoral width (DFW), and intercondylar femoral width (IFW) than women (P < .05). By contrast, the medial meniscus bone angle (MMBA) was lower in men than in women (P < .05). Women aged 31 to 40 years had a lower Insall-Salvati index (ISI) and lateral tibial posterior slope (LTPS) than those aged 21 to 30 years (P < .05), whereas men aged 31 to 40 years had a lower ISI than those aged 21 to 30 years (P < .05). Women with BMI ≥ 30 had a higher LFCW and MFCW but a lower ISI than those with BMI < 30 (P < .05). Men with BMI ≥ 30 had a higher LFCW, MFCW, DFW, and MMBA than those with BMI < 30 (P < .05). The use of value ranges structured according to demographic characteristics, rather than a single value range for all patient groups, may contribute to the evaluation and treatment of the morphological features that are thought to be effective in the development of internal knee injuries. These values may also shed light on future radiological risk scoring systems and artificial intelligence applications in medicine.

Morphometric MRI Evaluation of Three Autografts Used in Anterior Cruciate Ligament Reconstruction in Athletes

The purpose of the present study was to quantify the morphometric characteristics of three tendon autografts (hamstring tendons (HT), quadriceps tendon (QT), and patellar tendon (PT)) used in anterior cruciate ligament (ACL) reconstruction. For this purpose, knee magnetic resonance imaging (MRI) was obtained in 100 consecutive patients (50 males and 50 females) with an acute, isolated ACL tear without any other knee pathology were used. The level of the physical activity of the participants was determined using the Tegner scale. Measurements of the tendons' dimensions (PT and QT tendon length, perimeter, cross-sectional area (CSA), and maximum mediolateral and anteroposterior dimensions) were performed perpendicular to their long axes. Higher values were recorded as regards the mean perimeter and CSA of the QT in comparison with the PT and the HT (perimeter QT: 96.52 ± 30.43 mm vs. PT: 63.87 ± 8.45 mm, HT: 28.01 ± 3.73 mm, F = 404.629, p < 0.001; CSA QT: 231.88 ± 92.82 mm² vs. PT: 108.35 ± 28.98 mm², HT: 26.42 ± 7.15 mm², F = 342.415, p < 0.001). The length of the PT was shorter in comparison with the QT (53.1 ± 7.8 vs. 71.7 ± 8.6 mm, respectively, t = -11.243, p < 0.001). The three tendons showed significant differences in relation to sex, tendon type, and position as regards the perimeter, CSA, and the mediolateral dimensions but not for the maximum anteroposterior dimension.

Posterior Cruciate Ligament and Patellar Tendon Can Predict Anterior Cruciate Ligament Size for Planning During ACL Reconstruction in Pediatric Patients

Purpose

To establish correlations between the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and patellar tendon in normal pediatric knees to inform surgical planning for ACL reconstruction graft size.

Methods

Magnetic resonance imaging scans of patients ages 8 to 18 years were assessed. Measurements included ACL and PCL length, thickness, and width, and ACL footprint thickness and width at the tibial insertion. Interrater reliability was assessed with a random set of 25 patients. Pearson correlation coefficients were used to assess the correlation between ACL, PCL, and patellar tendon measurements. Linear regression models were used to test whether the relationships differed by sex or age.

Results

Magnetic resonance imaging scans of 540 patients were assessed. Interrater reliability was high for all measurements except PCL thickness at midsubstance. Sample equations for estimating ACL size are as follows: ACL length = 22.61 + 1.55∗PCL origin width (R² = 0.46; 8- to 11-year-old male patients), ACL length = 12.37 + 0.58∗PCL length + 2.29∗PCL origin thickness - 0.90∗PCL insertion width (R² = 0.68; 8- to 11-year-old female patients), ACL midsubstance thickness = 4.95 + 0.25∗PCL midsubstance thickness + 0.04∗PCL insertion thickness - 0.08∗PCL insertion width (R² = 0.12; 12- to 18-year-old male patients), and ACL midsubstance width = 0.57 + 0.23∗PCL midsubstance thickness + 0.07∗PCL midsubstance width + 0.16∗PCL insertion width (R² = 0.24; 12- to 18-year-old female patients).

Conclusions

We found correlations between ACL, PCL, and patellar tendon measurements that can be used to create equations that predict ACL size in various dimensions based on PCL and patellar tendon measurements.

Clinical Relevance

There is a lack of consensus on the ideal ACL graft diameter for pediatric ACL reconstruction. The findings from this study can assist orthopaedic surgeons to individualize ACL graft size for specific patients.

Anthropometric study as a predictor of anterior cruciate ligament sizes in Asian Indonesian population

OBJECTIVES

To evaluate whether anthropometric data can predict anterior cruciate ligament (ACL) sizes on magneti resonance imaging (MRI) in Asian population.

BACKGROUND

Reconstruction of ACL has been performed over a decade ago. Recently, more individualized ACL reconstruction is performed taking account of each patient's ACL characteristics. However, there has been limited study regarding ACL sizes in Asian Indonesian population. This study aimed to evaluate the role of anthropometric data in ACL sizes using MRI in Asian Indonesian population.

STUDY DESIGN

Retrospective Study.

METHOD

A series of 531 knees from 420 patients with knee pain and intact ACL confirmed by MRI study. Length, width and inclination angle of ACL were measured using a T2-weighted sagittal MRI 3.0 Tesla Magnetom Skyra. Height, weight, body mass index (BMI) and age were recorded. Multiple regression analysis was used to determine relationship between the anthropometric data and size of ACL measurements.

RESULT

ACL length and width were significantly different between male and female, consecutively. Mean ACL length was 35.36 ± 3.63 mm, male was significantly longer (36.59 ± 3.24 mm) compared to female (32.77 ± 2.99 mm), p < 0.0001. Mean ACL width was 10.23 ± 1.84 mm, male was significantly wider (10.85 ± 1.59 mm) compared to female (8.93 ± 1.64 mm), p < 0.0001. The mean ACL inclination angle was 47.75° ± 3.07° (range 40.17°-57.12°). The strongest correlation for ACL length was height and weight (r = 0.437; r = 0.341 consecutively, p < 0.0001). Females had stronger correlation compared to males for ACL length (R² = 0.489 vs R² = 0.418). ACL width showed weak correlation with anthropometric data. The following regression analysis equation was obtained for ACL length: ACL length = 60.697 - 0.11*age + 0.461*weight (kg) - 16.522*height (meter) - 1.093*BMI (R² = 0.539; p < 0.0001).

CONCLUSION

Anthropometric data can be utilized as a predictor of ACL length in Asian Indonesian population. The ACL length in Asian Indonesian population is shorter than that in Western population study.

CONTRALATERAL PATELLAR TENDON AUTOGRAFT IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

OBJECTIVE

To conduct a systematic review of literature about the use of contralateral patellar tendon autograft in anterior cruciate ligament reconstructions and present the results.

METHODS

The LILACS, MEDLINE, Cochrane, PubMed, Scielo and Google Scholar databases were searched without date restrictions for the keywords "anterior cruciate ligament reconstruction" combined with "contralateral" in the article title. After the studies were identified, two independent evaluators collected the qualitative characteristics of the studies and classified them according to clinical outcomes of these grafts as positive, neutral, or negative.

RESULTS

A total of 755 articles were found initially, and after detailed evaluation of all references, followed by a screening process and assessment of quality, a total of 11 studies were determined to be eligible for inclusion in this systematic review. Of these, 72.72% were level II studies, the most common level of evidence among the results. Positive results for this type of graft were found in 63.63% of the studies.

CONCLUSION

Based on the literature review, most of the included articles (63.63%) presented positive results for the use of contralateral patellar tendon grafts. Level of Evidence III; Systematic review.

Prediction of flexor tendon graft diameter in reconstruction of the anterior cruciate ligament by means of magnetic resonance imaging

OBJECTIVE

To evaluate the diameter of the flexor tendons in preoperative magnetic resonance imaging (MRI) examinations and compare this with the diameter of the graft obtained intraoperatively.

METHODS

This was a retrospective longitudinal epidemiological study. Forty-four patients were eligible for the study and their MRI examinations and surgical data were evaluated. The tendons were measured on MRI across their largest diameter in the axial plane, using the medial epicondyle of the femur as the slice level. In the surgery, routine graft preparation was performed, consisting of folding the gracilis and semitendinosus tendons to form a four-strand graft. Its measurement was recorded.

RESULTS

To evaluate the association between the variables, Pearson's correlation coefficient was estimated. A significant correlation was found between the measurements of the gracilis and semitendinosus tendons and the final diameter of the graft (p < 0.001). A ROC curve was fitted to the sum of the tendon diameters in order to determine a cutoff point associated with the graft diameter (≤8 mm or >8 mm). If the sum was greater than 5.28 mm, the chance of obtaining a graft larger than 8 mm would be 75%.

CONCLUSION

Measurement of the diameters of the gracilis and semitendinosus tendons through a preoperative MRI examination is a simple and effective way to predict the final size of the graft to be used in ACL reconstruction surgery.

Study on the relationship between the thickness of the anterior cruciate ligament, anthropometric data and anatomical measurements on the knee

OBJECTIVES

To ascertain thickness measurements on the anterior cruciate ligament (ACL) in its middle third on magnetic resonance imaging (MRI) scans and to assess whether there is any association between variations in ligament thickness and patients' heights and ages, along with variations in the anatomical measurements on the knee.

METHODS

MRI scans on 48 knees were evaluated. The anteroposterior size of the femoral condyles, interepicondylar distance, intercondylar distance and anteroposterior and mediolateral thicknesses of the ACL were measured. It was assessed whether there was any statistical relationship between ACL thickness and the patients' age, height or other measurements evaluated.

RESULTS

The mean thickness of the middle third of the ACL was 4.5 mm in the sagittal plane and 4.3 mm in the frontal plane. The anteroposterior thickness of the ACL in its middle third had a positive relationship with the size of the lateral condyle. The mediolateral thickness of the ACL in its middle third had a positive relationship with the size of the lateral condyle and with the intercondylar distance in the axial plane. There was no relationship between the thickness of the ACL and the patients' age or height.

CONCLUSION

The thickness of the ACL presented positive associations with the size of the lateral femoral condyle and the intercondylar distance.