Which Imaging Modalities are Neededfor Successful Treatment of Different Grades of Tibial Condylar Fractures?
Citation: “Which Imaging Modalities are Neededfor Successful Treatment of Different Grades of Tibial Condylar Fractures?”. American Research Journal of Radiology and Nuclear Medicine; Volume 1, 2017; pp:1-12
Copyright This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Purpose: For success of surgery on different types of tibial condylar fractures, what are the different radiological modalities, plain x-ray, CT or MRI should be used in each fracture type of Schatzker classification.
Question: Is the adding of CT or MRI to plain x-ray in tibial condyles fractures diagnosis can change the decision or the results of treatment?
Patients & methods: This study was prospectively performed on 40 patients presented by history of trauma or traffic accident complaining of pain, swelling and/or loss or weakness in leg movement. All cases were subjected to X ray, CT without contrast and with coronal and sagittal reconstruction and conventional MRI on the affected lower limb.
Results: This study included 22 males and 18 females. The main clinical presentation was pain and swelling in the affected limb (100% of cases) followed by loss of function (87.5%). The incidence of different types of Schatzker classification was as follows: Type I 15%, type II 12.5%, type IIIA 15%, type IIIB 17.5%, type IV 17.5%, type V 2.5% and type VI 20%. The overall accuracy of X-ray, CT and MRI for diagnosis of fracture site was 73.2%, 74.4% and 74.4% respectively, but the MRI soft tissue injuries assessment affected seriously the surgical decision.
Conclusion: CT scanning is more accurate than X-ray in precise localization of surgical landmarks and all tibial plateau fracture fragments. MRI is superior to CT in depiction of meniscal injuries and injuries to the collateral and cruciate ligaments and consequently the surgical decision can be changed completely in cases with bone comminution or associated soft tissue injuries.
Keywords: Tibial plateau, fracture; X-ray; CT; MRI; modalities.
Abbreviations: mAs, milliamperage-second; MCL, medial collateral ligament; ACL, Anterior cruciate
ligament; PCL, Posterior cruciate ligament
The Schatzker classification system for tibial plateau fractures is used by orthopedic surgeons to assess the primary injury and predict the prognosis as well as the accurate management. Many investigators have found that surgical plans based only on plain radiographic findings (X-ray) were changed when the patients :under wentpreoperative CT orMRI. The Schatzker classification divides tibial plateau fractures into six types, lateral plateau split fracture without depression (type I), lateral plateau fracture with depression (type II), compression fracture of the lateral(IIIA) or central (IIIB) tibial plateau, medial plateau fracture (type IV), bicondylar plateau fracture (type V), and plateau fracture with diaphyseal discontinuity (type VI) .
The location of soft-tissue injury as well as the degree of soft-tissue swelling guides the surgeons to the surgical approach and the timing of definitive surgery and helps also in making a decision of the need for provisional stabilization with an external fixator . CT and MRI seem to be more accurate than X-ray for management of tibial plateau fractures, and the use of cross-sectional imaging can improve surgical planning .
CT is used by most orthopedists to further characterize fractures of the tibial plateau and assess the depression of the tibia and the degree of displacement of the fractured parts. Generally, slice thickness should be minimized (1 mm is ideal) and high milliamperage-second (mAs) technique should be used .MRIis excellent for detecting ligamentous and meniscal injuries.A major advantage of MRI over CT is that MRI does not use ionizing radiations. However, MRI has a higher cost and is needs longer time to complete the study (25 minutes for MRI vs 20 seconds for CT), which means that motion artifact can be a problem .
Aim of this study is to describe the rule of plain x-ray, C T, and MRI in diagnosis of tibial plateau fractures, and which radiological modalities should be used in each fracture type, and if it can change the surgical decision or the results of treatment.
PATIENTS AND METHODS
Study design and population
This prospective study was performed in the period between August 2013 and September 2015 after approval of our faculty ethical committee and included 40 patients 22 males (55%) and 18 females (45%), with age ranged from 30-59 years (average: 42 years) presented with history of motor vehicle accident followed by pain, swelling and/orloss or weakness of leg movement. The cases were referred from orthopedic department, Zagazig University and conducted in Radiodiagnosisdepartment. Informed consent was obtained from all participants in the study.
Patients with tibial plateau fracture suggested clinically were included in the study. On the other hand patients with previous operations of the tibia and those with a contraindication to MRI examination (artificial heart valve, cardiac pacemaker, metallic stents or joint prosthesis except that made of titanium)were excluded from the study.All patients were subjected to complete history taking, full clinical examination and imaging studies includingX ray of the affected limb (Anteroposterior and lateral views), CT imaging (axial cuts with reconstruction sagittal and coronal images) and conventional MRI (T1WI, T2WI, proton density (PD) and short T1 inversion recovery [STIR] sequences).
Technique of computerized tomography examination
CT was done using 128 multislice machine (Philips, Ingenuity Core multislice 128 TM, Netherlands). The patient lied in supine position with knee extended and feet first into scanner. Straps were used to ensure patient stay in the correct position. The scanning parameters were as follows: Collimation: 1.25 cm, interval spacing: 0.65 cm, rotation time: 0.8 second.Thin axial slices were taken through the knee and leg and reconstructing the imagedata into sagittal and coronal planes.
Technique of MRI examination
All MRI studies were done using Philips machine (Philips Achieva, 1.5 Tesla). All patients were asked to get rid of any metallic objects. MRI study was done with the patients in the supine position using the standard knee coil and different sequences were taken (T1WI, T2WI, PD and STIR).
All data were collected, tabulated and statistically analyzed using SPSS 18.0 (SPSS Inc., Chicago, IL, USA). Continuous data were expressed as the mean ± standard deviation (SD) & median (range), while the categorical data were expressed as a number (percentage). Validity of X-ray, CT, MRI in diagnosis of tibial fracture was calculated with 95% confidence interval using diagnostic performance depending on sample 2x2 contingency tables generation using the operative and arthroscopic findings as the reference gold standard.
Patients’ demographic data and clinical picture
The patients’ demographic data and clinical picture are presented in table (1). The main clinical presentation was pain and swelling in the affected limb (100% of cases) followed by loss of function (87.5% of cases).
Table1. Demographic & Clinical data of the studied patients
Incidence of different types of Schatzker classification
The incidence of different types of Schatzker classification based on plain x-ray was as follows: Type I15%, type II (Fig. 1) 12.5%, type IIIA (Fig. 2) 15%, type IIIB 17.5%, type IV 17.5%, type V(Fig. 3) 2.5% and type VI 20%.
Fig 1. A male patient 60 years with knee trauma and fracture
A- (A) X-ray AP and lateral view which reveals fairly seen fracture line passing through tibial spine and lateral. tibial plateau
B&C and D ): axial and coronal CT cuts reveals split and depressed fracture of lateral tibial plateau ….so it) diagnosed as type II tibial plateau fracture
E&F) are MRI coronal T2WI and coronal STIR reveals fracture line passing through lateral tibial plateau and) medial plateau so upgrade the type of fracture to type V
MRI images show that lateral meniscial body is fragmented and dislodged in to depressed lateral plateau.
(A&B): X-ray AP and lateral views shows fracture line passing through lateral tibial plateau and tibial spine.
(C&D): Axial CT cuts, (E,F, G&H): sagittal and coronal reconstructed CT cuts , the images reveal split fracture of lateral tibial plateau and tibial spine with no depression, associated with multiple bony fragments and fracture upper fibula.
(m&J): MRI coronal T2WIs. Images (K&L) sagittal & coronal T1WI reveal fracture line involve lateral tibial plateau, fracture upper end of fibula , joint effusion as well as PCL avulsed tibial attachment. Evidence of bucket handle tear of Posterior horn of medial meniscus absent bow tie sign & double PCL and detached central fragment (of MM is seen at intercondylar notch just below PCL origin
A): X-ray AP view shows, fracture line hardly seen passing through tibial spine)
B,C&D) CT axial, sagittal and coronal cuts of the knee shows depressed fracture of tibial spine with) detached small intra-articular fragment
E,E’,F&F’) MRI sagittal T1WI and sagittal T2WIs show abnormal contour and signal of ACL denoting complete ACL) tear( avulsed tibial attachment with avulsed bone fragment ) with buckling of PCL
G) MRI coronal STIR images at 3 subsequent levels show bone marrow edema of tibial spine as well as MCL) tear and fluid signal is seen surrounding it
Diagnostic performance of X-ray
The diagnostic performance of X-ray in diagnosis of tibial fracture and associated injuries is presented in table (2). The sensitivity and specificity for detection of fracture site, displacement, bony fragments, ligamentous injury and meniscal injury were 96.3% and 50%, 4.4% and 93.8%, 1.4% and 92.9%, 1.5% and93.8%, 1.7% and96.2% respectively. The overall accuracy was 73.2%, 31.4%, 47.1%, 47.6% and 48.9% for diagnosis of fracture site, displacement, bony fragments, ligamentous injury and meniscal injury respectively.