Radiographic Coronal Thin Point as a Predictor of Shortening of Stable Pertrochanteric Fractures Treated with Proximal Femoral Nailing

Background: Comprehensive assessment of the distal radius always includes the standard AIM: To determine if radiographic coronal thin point can predict shortening among patients aged <85 years old with stable pertrochanteric fracture.

MATERIALS AND METHODS: A cross-sectional design was used involving 56 patients with stable pertrochanteric (SP) fractures managed by proximal femoral nailing (n=56). A PACS PLUS application was used to measure lateral wall thickness (LWT), coronal thin point (CTP), and lag screw, based on x-rays taken pre-operative, post-operative  and six months post-operative imaging of SP fractures were analyzed for those fractures with shortening of ≥15 mm post-fixation.

RESULTS: A lag screw length of  ≥15 mm was prevalent in 23.2% after six months postoperative, only two patients (3.6%) showed significant lag screw shortening ≥15 mm when compared to immediate post-operative measurement.

Results revealed that mean LWT (p=.8964) and mean CTP point (=0.679) among patients with significant shortening are the same in those patients without a significant shortening.

Using the Youden index suggests that the best cut-off score of CTP in predicting significant shortening is ≤4 mm. Using the best cut-off score of ≤4 mm showed that it is a significant predictor of shortening. It has a high sensitivity of 100% (95% CI 15.81 to 100), high specificity of 92.59 (95% CI 82.11 to 97.45), high AUC .96 (95% CI .88 to .995), and high diagnostic accuracy 92.86 ((95% CI 82.71 to 98.02).  Radiographic CTP is a reliable predictor of shortening.

CONCLUSION: A CTP value of ≤4mm measured on injury film of patients with pertrochanteric fractures is at risk of significant shortening of ≥15 mm six months after PFN surgery. 

Instability of fracture site is prevalent among those that shortened ≥15 mm six months after surgery, demonstrated by a higher lag screw measurement than non-significant shortening <15 mm. It implies that CTP contributes to the instability of stable pertrochanteric fractures, affecting fixation.