Reliability of Plain Radiographs Versus Magnetic Resonance Imaging to Measure Tibial Slope in Sports Medicine Patients: Can They Be Used Interchangeably?

Background: The slope of the tibial plateau has been proposed as a reason for failure of anterior cruciate ligament reconstruction. Purpose: To evaluate the interobserver reliability of measurements of tibial slope on radiographs versus magnetic resonance imaging (MRI) scans and to assess whether the modalities can be used interchangeably for this purpose. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: This retrospective study included 81 patients aged 18 to 30 years who were evaluated in a sports medicine setting for knee pain and who had lateral knee radiographs as well as knee MRI scans on file. Medial and lateral tibial plateau slope measurements were made by 3 blinded reviewers from the radiographs and MRI scans using graphic overlay software. The paired t test was used to compare measurements of the medial tibial plateau slope (MTPS) and lateral tibial plateau slope (LTPS) from radiographs and MRI scans. Intraclass correlation coefficients (ICCs) were calculated to determine intra- and interobserver reliability of measurements within each imaging modality, and Pearson correlation coefficients were calculated to determine the relationship between measurements on radiographs versus MRI scans. Results: Imaging from 81 patients were included. The average MTPS was significantly larger on radiographs compared with MRI scans (8.7° ± 3.6° vs 3.7° ± 3.4°; P < .001), and the average LTPS was also significantly larger on radiographs compared with MRI scans (7.9° ± 3.4° vs 5.7° ± 3.7°; P < .001). ICC values indicated good to excellent intraobserver agreement for all imaging modalities (ICC, 0.81-0.97; P ≤ .009). The ICCs for interobserver reliability of MTPS and LTPS measurements were 0.92 and 0.85 for radiographs, 0.87 and 0.83 for MRI based off the subchondral bone, and 0.86 and 0.71 for MRI based off the cartilage, respectively ( P < .001). Medium correlation was noted between radiographic and MRI measurements; Pearson correlation coefficients for radiographic versus subchondral MRI measurements were 0.30 and 0.37 for MTPS and LTPS, respectively. Conclusion: The average MTPS and LTPS were significantly larger on radiographs compared with MRI scans. Although tibial slope measurements using radiography and those using MRI are reliable between individuals, the measurements from radiographs and MRI scans cannot be used interchangeably, and caution should be used when interpreting and comparing studies using measurements of the tibial slope.

Normal anatomical variations of tibial plateau geometry in Indian population: a magnetic resonance image-based study

<p><strong>Background:</strong> Geometry of tibial plateau characterized by its medial tibial plateau slope (MTS), lateral tibial plateau slope (LTS), depth of concavity of medial tibial plateau (CMT), convexity of lateral tibial plateau on sagittal section and coronal tibial plateau slope (CTS) on coronal section of tibia.</p><p><strong>Methods:</strong> 500 subjects (male-250, female-250) were included in the study. Various tibial slopes of each subject were measured using magnetic resonance image (MRI) of knee joint. Data was analysed using appropriate statistical analysis.</p><p><strong>Results:</strong> When considering male and female one group (total population) mean (±SD) of MTS, LTS, CMT, CTS were 7.73±3.20⁰, 4.68±2.75⁰, 2.56±0.56 mm and 2.61±2.15⁰ respectively. In male population mean (±SD) of MTS, LTS, CMT, CTS were 6.94±3.2⁰, 3.77±1.85⁰, 2.7±0.55 mm, 3.06±2.39⁰respectively. In female population population mean (±SD) of MTS, LTS, CMT, CTS were 9.28±2.65⁰, 6.45±3.36⁰, 2.28±0.48 mm, 1.75±1.24⁰ respectively. Over all MTS and LTS was poorly correlated (r=0.43). Female had significant steeper MTS (p=0.013) and LTS (p=0.001) but had less CTS (p=0.04) and shallow CMT (p=0.012) compared to male.</p><p><strong>Conclusions: </strong>Knowledge of this study could be used in different operative orthopaedic procedures (like knee arthroplasty, high tibial osteotomy, tibial plateau fracture fixation), non-contact ACL injury risk assessment.</p><p> </p>

MR imaging of the anatomy of the anterior horn of the medial meniscus

Background In cadaveric and arthroscopic studies different insertion locations of the anterior horn of the medial meniscus (AHMM) have been described. Purpose To investigate if the different insertion locations of the AHMM, as described in cadaveric studies, can be determined on magnetic resonance imaging (MRI). Material and Methods MR images of 100 patients without meniscal tears on MRI were retrospectively evaluated. Two observers classified the AHMM insertion based on its position relative to the anterior tibial edge and the medial tibial spine. The association between AHMM insertion and tibial plateau slope, meniscal radial displacement, and anterior intermeniscal ligament (AIL) presence was investigated. Results The AHMM inserted posterior to the anterior tibial edge in 93 knees and anterior to the tibial edge in seven knees (= type III). Of the 93 knees with AHMM insertion posterior to the anterior tibial edge, 63 inserted lateral to the medial tibial spine (= type I) and 30 medial (= type II). The AHMMs inserting anterior to the tibial edge had a significantly ( P < 0.05) steeper anterior tibial plateau slope and a significantly ( P < 0.05) higher presence of the AIL. No significant difference in radial displacement was observed between the three insertion types ( P > 0.05). A strong inter- and intra-observer agreement was observed. Conclusion Three different bony insertion locations of the AHMM, as described in cadaveric studies, could be identified on MRI. All AHMMs inserting anterior to the tibial edge displayed an AIL. Whether there is a clinical correlation with these insertion patterns remains unclear.

Proximal Tibial Epiphysiodesis in a Growing Dog

Background: It is believed that the inclined tibial plateau angle to be a major cause of cranial cruciate ligament (CCL) rupture, and the treatment of this disease is the tibial plateau leveling for decrease the cranial tibial thrust. However, there are breeds predisposed to rupture of the cranial cruciate ligament and in this patterns breed the tibial plateau is more in­clined due to the conformation of the limb. The aim of this communication was to evaluate the effectiveness of the locking screw and cauterizing the growth plate of the tibial plateau as a preventive method of cranial cruciate ligament rupture. Case: In a young dog, one stifle joint randomly chosen for placing a screw in order to block the tibial plateau growth line. There was placed a 3.5 mm x 20 mm cancellous bone screw in the dorsocranial surface of the tibial plateau of the left hindlimb. Two months after the first surgical intervention, the contralateral limb was cauterized in the tibial plateau growth line. Electrocauterization was performed with a spatula electrode set at 60 watts, performing ablation on the cra­nial third of the tibial plateau physis with access to the medial and lateral surfaces of the proximal tibia. The electrode was placed against the physis for 10 seconds at each site. Both members were followed radiographically to measure the tibial plateau angle and observed the angle reduction. After 30 and 60 days post-surgery, the tibial plateau angle in left hindlimb decreased to 11o and -4o, respectively. However, the decrease plateau tibial angle was intense and severe and the screw was removed of the bone. However, even with the proximal tibial physis still open, withdrawing the screw did not alter the tibial plateau angle, which remained at -4º until the animal reached adulthood. The right left hindlimb was used as a control until the dog was 6 months old, when the tibial plateau angle exhibited a 26°. With the electrocauterization technique the tibial plateau angle decreased to 18° and 16° at 30 and 60 days after surgery, respectively, remaining at this last value until the animal completed its growth. Discussion: In the animals with cranial cruciate ligament rupture is indicate same surgical procedures like tibial plateau leveling osteotomy. In these cases, the recommended tibial plateau angle is aproximattely 5o. This study sought to block the line of growth of the tibial plateau to be reached an angle of approximately 5o. Epiphysiodesis technique with screw was already described for treating CCL rupture in young dogs, and the tibial plateau slope was reduced in all dogs studied. The surgical technique used was effective in blocking the physis; however, we observed that the tibial plateau slope was excessively modified and the screw was removed. This fact is explained by the dog’s immaturity, since the plateau leveling occurs more intensively in very young dogs. In epiphysiodesis using the electrocauterization technique, the same surgical principle of juvenile pubic symphysiodesis for treating coxofemoral dysplasia was used. However, in the current pilot study, it was unable to achieve the desired tibial plateau slope with this technique, possibly due to performing the procedure at an age in which the proximal tibial physis would have limited functional capacity. In this study, there was a reduction in the angle of the tibial plateau in both the techniques. However, further studies should be conducted to in order to confirm the actual effectiveness of both techniques described in this report. Keywords: cranial cruciate ligament, locking screw, electrocauterization, stifle joint