Does multidetector computed tomography unravel the hidden domains of conventional radiography in calcaneal fractures?

INTRODUCTION

The Calcaneal fractures are the most common fractures among the tarsal bones, representing 60-75% of all the tarsal fractures in adults and constitutes approximately 2% of all fractures.¹ These fractures are more common in younger age group predominantly in males.^2,3 The first assessment of Calcaneal fractures depends on conventional radiography. The Calcaneal fractures are often identified on a lateral ankle radiograph. Additional views can be requested if required. The bohler and gissane angles are used to assess the severity of fractures. Computed tomography is modality of the choice to evaluate Calcaneal fractures. It gives exact delineation of fracture and can depict with greater accuracy whether the fracture is intra articular or extra articular based on sub-talar joint involvement.⁴ In addition to delineation, the cross-sectional imaging also helps to evaluate the other fractures and soft tissue and muscular injuries. Through MPR and VR reconstruction is possible to assess accurately the fracture lines, dislocation, crushing, the morphology and the involvement of the articular surfaces, allowing to choose appropriate treatment and have a better prognostic evaluation. Early diagnosis facilitates treatment of fracture thus reduces the long term complications.⁵ The aim of this study was to assess conventional radiography versus computed tomography for evaluation of Calcaneal fractures taking operative/MRI findings as gold standard.

METHODS

This was a cross sectional observational study conducted over period of 2 years from January 2021 to February 2023 in a tertiary care hospital of SKIMS Medical College (J&K) and was approved by the ethical committee. This study included 68 patients with history of significant foot trauma, The cases included in the study were either the diagnosed Calcaneal fractures on conventional radiography or having high clinical suspicion for Calcaneal fracture.

Patients with severe medical ailments and unfit for surgery are excluded. All patients were subjected to complete history taking, physical examination and digital radiographic examination and further computed tomographic assessment of traumatic foot. All patients underwent the Same MDCT protocol using 0.5mm collimation, image thickness of 0.5mm with tube voltage of 120 kV and 240 mAs. Images were carried in both bone window for fracture classification and soft tissue window for tendon entrapment and other soft tissue abnormalities. Saggital, coronal and axial 2D and 3D MPR reconstruction were carried out. Fracture classification: Classification of the fracture was done according to Sander’s as follows; Type I-non displaced or displacement less than 2 mm. Type II-fractures consisted of two articular pieces from a single intra-articular fracture line. Type III- Fractures consisted of three articular pieces from two fracture lines. Type IV-comminuted fracture.⁶

Statistical analysis

The data was analyzed by the principal investigator with advice from a statistician. SPSS 23.0 (IBM, Armonk, NY, USA) was used for the statistical analyses. With the surgical findings taken as the gold standard, the sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), and diagnostic accuracies of digital radiography and computed tomography for the diagnostic evaluation of Calcaneal fractures were calculated, p<0.05 was taken to indicate statistical significance.

RESULTS

This study included 68 patients which were diagnosed with Calcaneal fracture. 40 were males (58.8%) and 28 females (41.1%) with mean age of 32 years. The associated injuries were: soft tissue edema in 32cases (47%), muscle injuries in 8 (11.7%) and tendon injuries in 5 cases (7.3%). 21 patients presented with multiple fractures in other bones (35%). The extra articular Calcaneal fractures were present in 22 cases (32.3%) and intra articular fractures were noted in 48 cases (70.5%). The frequency and percentage according to sanders classification was more in type IV fracture.

The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy was 92.86%, 33.33%, 86.6%, 50%, 82.3% for digital radiograph and 98.3%, 71.4%, 96.77%, 83.33%, 95.59% for computed tomography respectively. The sensitivity, specificity, PPV, NPV and diagnostic accuracy was far better in CT than digital X-ray in diagnostic evaluation, accurate depiction and treatment planning for Calcaneal fractures. Representative Case: 38 yr lady presented with history of fall from height is depicted in (Figure 1).

DISCUSSION

The prospective observational study revealed calcaneal fractures were the most common fractures among the tarsal bones. Our study revealed that calcaneal fractures were more common in young males than females and most common cause found was fall from height. These results were in concordance with the study done by Sanders et al which found the similar results.² The associated injuries in most patients were soft tissue edema, muscle injuries, tendon injuries and fractures in other bones. The majority patients about 47% presented with associated soft tissue edema and 32.3% present with fractures in other bones as well, which were in concordance with the study done by Berberian et al.⁷ The intra articular calcaneal fractures were more common in our study than the extra articular and comprised 70.5% of calcaneal fractures. These results were in agreement with the study done by Miller et al.⁸ The frequency and percentage according to sanders classification was more in type IV fracture in our study and comprised 38% of the cases. while as, type I were the least. Similar results were established by the Brunner et al who stated that type I was uncommon and other types from type II to type IV were nearly similar in their percentage of occurrence.⁹ The Conventional radiograph reveals the 92.8% sensitivity, 33.33% specificity, 86.6% PPV and 82.3% diagnostic accuracy. Zhang et al approved the sensitivity and specificity of about 94.85 and 79.09% respectively in calcaneal fractures.¹⁰ Madadi et al Vannier et al affirmed the similar results.^11,12 The computed tomographic analysis of calcaneal fractures reveals the 98.3% sensitivity, 71.4% specificity, 96.7% PPV, 83.3%, NPV and 95.59% diagnostic accuracy. Madadi et al agreed with us in considering CT as high specific modality for diagnosis and characterization of calcaneal fractures.¹² Tanyu et al shows concordance with our results and confirmed the enhanced diagnostic value of CT scan for calcaneal fractures.¹³ Thus we find that sensitivity, specificity and diagnostic accuracy was far better in Cross sectional imaging than conventional imaging in diagnosis, characterization, classification, treatment planning and indicator to determine the outcome of the treatment. The development of multidetector CT has transformed CT from a simple cross sectional imaging technique to an advanced, three dimensional 3-D imaging modality, enabling excellent 3-D displays. Its advantages over its predecessor, single slice helical CT, are isotropic imaging capability and ease of interpretation.

Limitations

Patients with minor suspicion for calcaneal fracture were subjected to CT imaging which subsequently increased the radiation and economic burden. So, better segregation and decision making is highly recommended.

CONCLUSION

CT imaging of calcaneal fracture is utmost important to unreveal the hidden domains of conventional radiography, thus helping in exact delineation, characterization and helping in formulation of highly yielding treatment modality.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee

REFERENCES

1. 1. Eiff MP, Hatch RL. Fracture management for primary care. 3^rd ed. Philiadelphia; Elsevier Saunders: 2012.
2. 2. Sanders RW, Clare MP. Cacaneous fractures. In: Rockwood and Green’s fractures in adults. Bucholz, RW, Heckman JD, Court Brown CM, Tornetta P, eds. 7^th ed. Philadelphia: Lippincott Williams and Wilkins; 2010:2064.
3. 3. Mitchell MJ, Mckinley JC, Robinson CM. The epidemiology of calcaneal fractures. Foot. 2009;19: 197.
4. 4. Kenneth B, jose AP, Samuel OP, Angel AG, Edgar C, Jorge AV. Calcaneal fractures. Foot Ankle. 2010;21; 32.
5. 5. Epstein N, Chandran S, Chou L. Current concepts review: intraarticular fractures of the calcaneus. Foot Ankle Int. 2012:33:79-86.
6. 6. Sanders R, Fortin P, Dipasquale T. Operative treatment in 120 displaced intraarticular calcaneal fractures. Results using a prognostic computed tomography scan classification. Clin Orthop Relat Res. 1993;290:87-95.
7. 7. Berberian W, Sood A, Karanfilian B. CT classification and results of operative treatment. Foot Ankle Clin. 2013;55:43-51.
8. 8. Miller MD, Thompson SR. Miller’s review of orthopaedics. 8th ed. Philadelphia, PA: Elsevier; 2019.
9. 9. Brunner A, Heeren N, Albrecht F, Hahn M, Ulmar B, Babst R. Effect of three dimensional tomography reconstructions on reliability. Foot Ankle Int. 2012;33 (9):33-727.
10. 10. Zhang T, Chen W, Su Y, Wang H, Zhang H.Does axial view still play an important role in dealing calcaneal fractures?. BMC Surg. 2015;15 (1):19.
11. 11. Vannier MW, Hildebolt Cf, Gilula LA, Pilgram TK, Mann F, Monsees BS, et al. Calcaneal and pelvic fractures; diagnostic evaluation three-dimensional computed tomography scans. J Digit Imaging. 1991; 4(3):143-52.
12. 12. Madadi F, Moghaddam AS. Diagnostic value of imaging modalities for suspected calcaneal fractures: A systemic review of literatures. Clin Res Foot Ankle. 2016;87(2):186.
13. 13. Tanyu MO, Vinee P, Wimmer B. Value of 3D CT Imaging in fractures os Calcis. Comput Med Imaging. 1994;18(3):137-43.