Subtrochanteric Fractures/ AFF

• Proximal fragment is abducted, externally rotated, and flexed by iliopsoas and external rotators
• Distal fragment is adducted and shortened by adductors

• Based on UK NICE Guidelines, it is 5cm of bone distal to the lesser trochanter
• https://www.nice.org.uk/guidance/qs16/chapter/Quality-statement-5-Subtrochanteric-fracture

• Historically - Russell Taylor Classification - based on involvement of piriformis fossa (historically used to differentiate fractures amenable to IM nail with piriformis entry vs plate)
• 1 = piriformis fossa entry not involved
• 2 = piriformis fossa involved
• Number of parts – Seinsheimer

1. 1 = undisplaced
2. 2 = 2-part displaced
3. 3 = 3-part displaced
4. 4 = comminuted with > 4 parts
5. 5 = subtrochanteric with greater trochanter extension

• Ask for prodromal pain
• Contralateral pain – for prophylactic nailing

• Hamilton Russell Traction - draw!

6 considerations

1. Positioning - lateral or traction table
2. Implant choice - based on NICE guidelines - long IM nail
3. Overcoming deforming forces - with tools such as ball spike pusher, Schanz pin, cerclage wires, and collinear clamps
4. Starting point - aim to prevent varus as well as overcoming bowed femur
1. Especially in Asians and in osteoporosis
2. Ernest Kwek et al. - start slightly anterior and lateral and aim posterior and medial to overcome bow. However, need to be cognizant of varus malreduction during this process.
1. https://pubmed.ncbi.nlm.nih.gov/31560109/
5. Contralateral prophylactic nailing
6. Treat underlying cause
1. May need drug holiday; work closely with endocrinologist

• Lateral vs Traction table
• Lateral advantages – counteracts iliopsoas flexion forces, brings GT closer to skin (good for obese patients)
• Disadvantages – may need manual traction, presence of contralateral prosthesis may affect imaging
• However, in my practice, I usually operate on a traction table.

• Reduction tools – Schanz pin to proximal fragment, cerclage wires, large bone clamps, Poller screws, finger tool, ball spike pusher, femoral distraction, collinear clamp

• Based on the NICE guidelines, I will use an intramedullary and not an extramedullary implant
• https://www.nice.org.uk/guidance/cg124/chapter/Recommendations#surgical-procedures

• There is literature pertaining to sliding extramedullary devices for subtrochanteric fractures, but patient selection is important - the medial cortex must be intact and non-comminuted to allow the plate to act as a tension band
• Ekstrom et al. in JOT 2006 found no major difference in functional outcomes or complications between nail and Medoff sliding plate
Ekstrom Subtroch.pdf342.3KB
• However, a study by Rahme et al. found higher revision rates (28% vs 0%) when using fixed angle plates.
rahme2007.pdf230.4KB
• Nevertheless, I will use the NICE guidelines to guide my treatment of subtrochanteric fractures

• 2 ways - implant choice and technique
• Implant choice
‣
Use a nail of smaller radius of curvature = TFNA
• Synthes TFNA has the smallest radius (more bowed) = Radius 1m
• Synthes PFNA 1.5m
• Zimmer Natural nail, CMN = 1.27m (24-34cm) - 1.4m (36-42cm) - 1.5m (44-48cm)
1. Use nail of smaller diameter
2. Use nail with piriformis-start nail (basically straighter nail) [Ernest Kwek Paper]
• Technically, based on Ernest Kwek's paper in 2019, the entry point should allow the nail to accommodate for the bow.
• This can be done with a more ANTERIOR and LATERAL starting point to prevent anterior and lateral perforation

• Varus (due to gluteal muscles pulling) and procurvatum (due to iliopsoas pulling)

• Evidence suggests that AFF are stress fractures.
• There is generalized suppression of bone remodelling due to bisphosphonates.
• Since remodelling action localizes at areas developing stress fractures, this adversely affects the intracortical repair of developing stress fractures.

• Based on NEJM study of 196,000 women on bisphosphonates, 277 had fractures, 1.74 fractures per 10,000 patient-years.
• It is almost 6 times more likely in Asians compared to whites.
• No association with weight.

• 5 major
• 1 from lesser trochanter to supracondylar region,
• 2 minimal trauma,
• 3 short oblique/transverse fracture,
• 4 non-comminuted,
• 5 complete fracture
• 7 minor
• 1 Lateral periosteal reaction,
• 2 increased cortical thickness,
• 3 prodromal symptoms,
• 4 bilateral,
• 5 delayed healing,
• 6 use of medications (PPI, Steroids, BP),
• 7 comorbid conditions (low Vitamin D)
J of Bone Mineral Res - 2013 - Shane - Atypical Subtrochanteric and Diaphyseal Femoral Fractures Second Report of a Task.pdf314.0KB

• 20% contralateral fracture if you stop bisphosphonates
• If you do not stop, 50% risk of contralateral fractures