Anatomy
1st metatarsal base is: concave or convex?
Concave
What is the orientation for the cut of the Mau osteotomy?
Dorsal distal to plantar proximal
What is the orientation of the Ludloff osteotomy?
Distal plantar to proximal dorsal
The Scarf osteotomy was popularized in Europe for what 2 reasons?
1. Inherent stability
2. Does not violate blood supply to 1st metatarsal (from plantar origin)
Indications for mid shaft osteotomies?
Short metatarsal
Distal head procedures not adequate
Moderate IM (12-20)
Need to avoid base wedge/Lapidus
Original Mau/Ludloff were fixated how?
No fixation
What shape does base of 1st met become as it approaches the base, at its articulation with medial cuneiform?
Triangular
What tendon is at risk when performing Mau osteotomy?
Where does it insert?
Peroneus longus
Base of 1st metatarsal
The Ludloff is inherently MORE or LESS stable than Mau
Less
Is the scarf osteotomy considered rotational or translational?
Translational
Contraindications to mid shaft osteotomies?
1st MPJ arthritis
Poor bone quality
Complication you can see in a scarf osteotomy?
Troughing
Where on the 1st metatarsal is the nutrient foramen?
On the lateral surface of the shaft
Where does the dorsal cut start for the Mau osteotomy?
1.5-2cm proximal to 1st MPJ
What is the angle of the cut?
30 degrees
When making the "z cut", which portion of the cut do you perform FIRST?
Dorsal cut
What are the two types of plane of motion osteotomies?
Translational
Rotational
If shaft osteotomy performed and not enough IM correction achieved, what distal procedure can be added?
What is the risk of inserting screws directly plantarly?
What direction should screws be oriented instead?
Directly plantarly = won't capture plantar fragment
Should be slightly medially oriented
What type of malunion can you get with a Ludloff osteotomy that you see less commonly with Mau?
What is the maximum percentage of translation that you can safely achieve?
50%
What is the maximum translation you can achieve with Mau/Ludloff osteotomies?
5mm
Post op recommendations re: weight bearing for Scarf?
Over-rotating Mau/Ludloff can cause what to happen at the 1st MPJ?
Incongruency --> arthritis
Why is a lag screw not recommended?
Can cause loss of correction
What is the angle of the dorsal and plantar cuts?
60 degrees
Closer to the 1st met cuneiform joint = MORE or LESS rotation at the distal capital fragment?
LESS
What is the 1/3, 2/3 rule for a scarf osteotomy?
At distal cut:
⅓ of bone dorsal to osteotomy
⅔ of bone plantar to osteotomy
Reverse on proximal cut