Preoperative ultrasound predicts the intraoperative diameter of the quadriceps tendon autograft more accurately than preoperative magnetic resonance imaging for anterior cruciate ligament reconstruction.

PURPOSE: Sizing of potential autografts is essential to match the native anterior cruciate ligament (ACL) dimensions when performing ACL reconstruction (ACLR). We aimed to investigate the accuracy and reliability of the thickness and cross-sectional area (CSA) assessments for the prediction of the intraoperative diameter of the QT autograft using preoperative ultrasound and MRI. METHODS: Thirty patients (mean age ± standard deviation, 19.9 ± 5.0 years), who underwent ACLR using QT autograft, were included. The maximum thickness of the QT was assessed at 15 and 30 mm proximal using ultrasound with a long axis image, and at 15 mm proximal to the superior pole of the patella using MRI with a sagittal image. The CSA was assessed at the central 10 mm of the medial-lateral QT width at 30 mm proximal using ultrasound with a short axis image, and at 15 mm proximal to the superior pole of the patella using MRI with an axial image. Intraoperatively, QT autograft was harvested with a 10 mm width and the diameter was measured using a graft sizing device. RESULTS: Intra- and inter-observer reliabilities of all measurements using ultrasound and MRI were good (Intra-class correlation coefficient, 0.720-0.941). Correlation coefficient with the intraoperative diameter of the QT autograft was higher in ultrasound (R = 0.738-0.791, P < 0.001) than MRI (R = 0.449-0.543, P = 0.002-0.013). CONCLUSIONS: Preoperative ultrasound predicted the intraoperative diameter of the QT autograft more accurately than MRI. Ultrasound may be used clinically to assure a sufficiently large QT autograft diameter to match the diameter of the patient's native ACL. LEVEL OF EVIDENCE: Level III.

Morphological Evaluation of the Quadriceps Tendon Using Preoperative Ultrasound in Anterior Cruciate Ligament Reconstruction.

BACKGROUND: An evaluation of quadriceps tendon (QT) morphology preoperatively is an important step when selecting an individually appropriate autograft for anterior cruciate ligament (ACL) reconstruction. However, to our knowledge, there are no studies that have assessed the morphology of the entire QT in an ACL-injured knee preoperatively using ultrasound. PURPOSE: We aimed to investigate the morphological characteristics of the QT using preoperative ultrasound in ACL-injured knees. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 33 patients (mean age, 26.0 ± 11.5 years) with a diagnosed ACL tear undergoing primary ACL reconstruction were prospectively included. Using ultrasound, short-axis images of the QT were acquired in 10-mm increments from 30 to 100 mm proximal to the superior pole of the patella. The length of the QT was determined by 2 contiguous images that did and did not contain the rectus femoris muscle belly. The width of the superficial and narrowest parts of the QT, the thickness of the central and thickest parts of the QT, and the cross-sectional area at the central 10 mm of the superficial QT width were measured at each assessment location. The estimated intraoperative diameter of the QT autograft was calculated using a formula provided in a previous study. RESULTS: There were no significant relationships between QT morphology and any of the demographic data collected. The length of the QT was less than 70 mm in 45.5% of patients (15/33). The width, thickness, cross-sectional area, and estimated intraoperative diameter of the QT autograft were significantly greater at 30 mm than at 70 mm proximal to the superior pole of the patella. CONCLUSION: Preoperative ultrasound may identify a QT that is too small for an all-soft tissue autograft in ACL reconstruction. Furthermore, harvesting a QT with a fixed width may result in autografts that are smaller proximally than they are distally. Assessing the morphology of the QT preoperatively using ultrasound may help surgeons to adequately reconstruct the native length and diameter of the ACL with a QT autograft.

In situ cross-sectional area of the quadriceps tendon using preoperative magnetic resonance imaging significantly correlates with the intraoperative diameter of the quadriceps tendon autograft.

PURPOSE: Preoperative assessment to determine the sizes of potential autografts is necessary for individualized anterior cruciate ligament reconstruction (ACLR). However, no study has investigated the prediction of the intraoperative diameter of the quadriceps tendon (QT) autograft based upon preoperative imaging. This study investigated the correlation between the intraoperative diameter of a QT autograft and in situ thickness or cross-sectional area (CSA) measured using preoperative MRI. METHODS: Thirty-one knees of 31 patients (mean age 20.9 ± 5.0 years) who underwent individualized anatomic ACLR using all soft tissue QT autograft were included retrospectively. At 15 mm proximal to the superior pole of the patella, the maximum QT thickness was assessed in the sagittal plane and the CSA was assessed at the central 10 mm of the QT in the axial plane. The angle between the axial plane and a line perpendicular to the QT longitudinal axis was used to calculate an adjusted CSA using a cosine function. Intraoperatively, each QT autograft was harvested with 10 mm width and the diameter was measured using a graft sizing device. RESULTS: Intra- and inter-observer reliabilities of all measurements using preoperative MRI were excellent (intra-class correlation coefficient, 0.833-0.970). Significant correlations were observed between the thickness, CSA, or adjusted CSA, and the intraoperative diameter (R = 0.434, 0.607, and 0.540, respectively; P < 0.05). CONCLUSIONS: The CSA correlated most strongly with the QT autograft diameter. For individualized anatomic ACLR, measuring in situ CSA can be useful for preoperative planning of appropriate graft choices prior to surgery. LEVEL OF EVIDENCE: III.

MRI evaluation to predict tendon size for knee ligament reconstruction.

BACKGROUND: The aim of this study is to evaluate a possible correlation between specific anthropometric parameters and sizes of knee tendons commonly used for ACL reconstruction. We hypothesized that specific clinical and radiological knee measurements could be better tendon sizes predictors than age, gender, height and weight. MATERIALS AND METHODS: 100 consecutive patients were enrolled and 77 patients met the inclusion criteria of the study. All patients underwent a MRI of the knee with a 1.5 T super conducting MR System. For each patient, anthropometric data such as gender, height, weight, body mass index (BMI) and knee circumference were recorded. Specific MRI knee measurements were performed on each study: patellar tendon (PT) thickness and length, quadriceps tendon (QT) thickness, semitendinosus tendon (ST) diameter, gracilis tendon (GR) diameter, the largest patella and intercondylar width. RESULTS: The mean ST diameter, QT thickness and PT thickness were higher in males than in females. No significant differences were noted between males and females concerning GT diameter and the knee circumference. In addition, male knees had greater patellar and intercondylar width than female knees. Significant, but only weak correlations were found between patient anthropometric data and hamstrings diameter, PT length, and QT and PT thickness. Intercondylar and patellar width present a moderate correlation between PT thickness, PT length and ST diameter. CONCLUSION: The intercondylar and patellar width presented a moderate correlation with PT thickness, PT length and ST diameter. Further, weak correlations were found between patient anthropometric data (gender, weight, height, BMI) and GR and ST diameter, PT length, and QT and PT thickness. This results may help surgeons during preoperative planning, specifically regarding graft choice and size. LEVEL OF EVIDENCE: III.

Can we predict the size of frequently used autografts in ACL reconstruction?

PURPOSE: This study presents a method to measure the size of quadriceps, patellar tendon and hamstring autografts using preoperative magnetic resonance imaging (MRI). METHODS: Sixty-two subjects with a mean age of 25 ± 10 years who underwent ACL surgery between 2011 and 2014 were included. Patient anthropometric data were recorded for all subjects. During surgery, the respective autograft was harvested and measured using commercially available graft sizers. MRI measurements were performed by two raters, who were blinded to the intra-operative measurements. RESULTS: The inter- and intra-rater reliability was ≥0.8 for all MRI measurements. The intra-class correlation coefficient between the MRI measurement of the graft and the actual size of the harvested graft was 0.639. There were significant correlations between quadriceps tendon thickness and height (r = 0.3, p < 0.03), weight (r = 0.3, p < 0.01), BMI (r = 0.3, p < 0.04) and gender (r = -0.4, p < 0.002) and patellar tendon thickness and height (r = 0.4, p < 0.01), weight (r = 0.3, p < 0.01) and gender (r = -0.4, p < 0.012). CONCLUSION: Preoperative MRI measurements of quadriceps, patellar tendon and hamstring graft size are highly reliable with moderate-to-good accuracy. Significant correlations between patient anthropometric data and the thicknesses of the quadriceps and patellar tendons were observed. Obtaining this information can be useful for preoperative planning and to help counsel patients on appropriate graft choices prior to surgery. LEVEL OF EVIDENCE: III.