Atypical Femur Fractures

Atypical Femur FracturesAtypical femur fracture xray

 

Site

 

Subtrochanteric

Lateral femoral shaft

 

Aetiology

 

Stress fractures

 

Associated with long term bisphonate use

 

Bisphosphonates

 

Black et al. NEJM 2020

- reduction of hip fracture risk v risk of atypical femur fracture

- 10 year period

- 196,000 women > 50, 277 atypical femur fractures

- differences dependent on race

- in white women, over 3 years prevented 149 hip fractures and caused 2 atypical femur fractures

- in asians, over 3 years prevented 91 hip fractures and caused 8 atypical femur fractures

https://pubmed.ncbi.nlm.nih.gov/32813950/

 

Dell et al. Osteoporosis International 2018

- recommendations for drug holidays

- consider DEXA scan or other imaging every 3 - 5 years

- look for any focal or generalised lateral femoral cortical changes

https://pubmed.ncbi.nlm.nih.gov/29675745/

 

Clinical

 

Will typically have thigh pain for some times

 

Xray

 

Thickening

 

Lateral femur

- tension side

- see thickening of the lateral cortex

- beaking

- most common in the subtrochanteric region, but can be in shaft

 

Atypical femur fracture xrayAtypical femur fracture

 

 

Atypical femur fracture CTAtypical femur fracture CT 2

 

Incomplete Fracture

 

Stress Fracture Lateral

 

Complete fracture

 

Femoral stress fracture

 

Treatment

 

Surgery

 

Koh et al. Bone Joint J 2017

- systematic review

- nonoperative treatment of complete fractures failed in 50%, and surgery achieved union in 97%

- complete fractures - IMN nonunion rate 12.9%, plate fixation nonunion rate 31%

- must discontinue bisphonates

- mean time to union 7 months post surgery

https://pubmed.ncbi.nlm.nih.gov/28249967/

 

Nail aptypical 1Nail atypical 2

 

Femoral stress fractureFemoral Stress Fracture IMN

 

Medical

 

Refer to osteoporosis

- cease bisphosphonates

- treat with calcium and vitamin D

- consider teriparatide

https://pubmed.ncbi.nlm.nih.gov/26713309/

 

Compression Stress Fractures

 

Medial femur

- rare

- usually unite

- NWB

 

Stress Fracture Medial