Interest in curves: when the radius of curvature matters in femur fractures. A CT based morphometric study

PURPOSE

In today's era, fractures of the femur are primarily managed with intramedullary devices. Keeping in mind the anatomical sagittal bow of the femur, intramedullary devices have been devised with an anterior bow, but this varies amongst various manufacturers - leading to complications such as anterior cortex impingement beyond the isthmus and posterior cortical opening at the fracture site. We intend to find the average radius of curvature (ROC) of the anatomical bow of the femur and the variation of the same.

METHODS

Radiographic data of 150 normal femur scans done in 81 patients were loaded in the Mimics 21.0 software (Materialise, Leuven, Belgium). A centerline (of the medullary cavity) was created using the software. A best-fit circle was created in the sagittal plane involving a major part of the centerline, and ROC was calculated.

RESULTS

We found the average ROC of our data was 1027.2, with a standard deviation of 241.55. ROC and length of the femur (an indirect measure of height) had a slight positive correlation (r = 0.36; p < 0.05); and a highly positive correlation in the ROC of the left and right femurs of the same individuals (r = 0.605; p < 0.05).

CONCLUSIONS

The usual ROC of intramedullary nails is commonly > 1300 mm, much higher than the average ROC we identified in our population. Thus, we conclude that implants with smaller ROC in the range of 1100 mm are needed, leading to better implant placement in the canal and avoiding complications of anterior cortex impingement and preventing fracture gap widening in our setting.

Femoral Shaft Fracture in Post-polio Syndrome Patients: Case Series from a Level-I Trauma Center and Review of Literature

BACKGROUND

Femoral shaft fracture in patients of post-polio syndrome (PPS) represents an uncommon yet complex injury pattern. Poorly developed soft-tissue envelope, decreased muscle bulk, reduced vascularity, regional osteopenia, joint contractures, and altered bony anatomy impose significant surgical challenges. Thorough pre-operative planning is imperative as each case requires individualized approach and method of fixation. The aim of the study was to analyze the clinical outcomes in such patients following fracture fixation and to assess the surgical challenges encountered and provide solutions.

MATERIALS AND METHODS

A retrospective case series of 33 patients with femoral shaft fracture in PPS limbs was undertaken. Mode of injury, method of fixation, surgical time, intra-operative blood loss, union time, and complications were recorded.

RESULTS

Low-energy fall was the most common mechanism of injury (73%). Thirty-three patients underwent fixation with intramedullary nailing being the most common mode (79%). Femoral canal diameter, femoral bow, fracture location and morphology and clinical deformities of the patients are key governing factors that determine the choice of implant. Locking plates, pre-contoured anatomical plates, and titanium elastic nailing system offer an alternative in patients unsuitable for nailing. With no difference between various implants, average time for bone healing was 13.8 ± 4.4 weeks. All patients resumed full weight-bearing mobilization and returned to pre-injury activity status at the end of 6 months post-surgery.

CONCLUSION

With detailed pre-operative work-up, contemplating intra-operative difficulties, individualized surgical plan, careful handling of soft tissues, and availability of back-up implants, good clinical outcomes can be achieved in femur fractures in PPS patients.