48 and 49 - Metatarsalgia I and II Flashcards
1
Q
Metatarsalgia
A
- Forefoot pain under metatarsal heads
2
Q
Reasons for metatarsalgia
A
o Soft tissue
o Bone abnormalities
o Biomechanical abnormalities
3
Q
Bone abnormalities leading to metatarsalgia
A
o Long metatarsal (commonly the 2nd) o Plantarflexed metatarsal o Hammer toe o Enlarged metatarsal head o Arthritis o Freiberg’s infarction o Stress fracture
4
Q
Soft tissue abnormalities leading to metatarsalgia
A
o Calluses (secondary to bony abnormalities) o Neuroma o Capsulitis o Plantar plate pathology o Hypermobile 1st ray o Equinus
5
Q
Plantar calluses
A
- Most plantar calluses are due to a biomechanical over-load
- You have increased pressure and the callus is the body’s way of trying to protect itself
6
Q
Hypermobile first ray
A
- Rays 2 and 3 have little motion (relatively static)
- 1st and 5th rays have own axis
- If 1st or 5th hypermobility is present, it can place increase stress on adjacent metatarsal
- Pronated foot type can also lead to this
- If the 1st ray elevates (in diagram), you can see how the 2nd and 3rd metatarsals are taking on an additional load
- This can occur in pronation as well
7
Q
Retrograde buckling
A
- Normal (dashed line): the toe is straight
- Buckling (solid line): proximal phalanx dorsiflexes, causing
the metatarsal to plantarflex, making it more prominent
and high pressure, so calluses commonly form
8
Q
Metatarsal length
A
Metatarsal parabola
o Nice even arc is present here
o 2nd metatarsal is supposed to be slightly longer
(peak of arc), but not sticking way out
o Overloading can also occur with a short 1st met
Metatarsal tangent angles
o 2nd metatarsal is not part of a nice arc
o Longer and sticking out too far
9
Q
Gait cycle
A
- The stance phase is more where we run into problems
- If the 2nd metatarsal is a lot longer than the rest of the metatarsals, it will have contact for much longer than the other metatarsals, leading to increased pressure and pain
10
Q
Now we are moving on to BONE pathology
A
FYI
11
Q
Long metatarsal
A
- Usually 2nd or 3rd metatarsal (Congenital or iatrogenic)
- May get hammering of digit due to elongation (Retrograde buckling due to tendon imbalance (tendons need to reach too far))
- May get plantar callus
- Chronic overloading can lead to capsulitis/plantar plate tears (remember the plantar plate is just the thickening in the capsular structure)
- Excess length can indirectly cause it to be plantarflexed
12
Q
Conservative treatment of long metatarsal
A
o Metatarsal pad (placed proximal to metatarsal head to relieve pressure from head)
o Callus debridement (try to keep callus down to further reduce pressure)
o Budin splint (toe goes through elastic strap which pulls the toe down flat in the shoe)
13
Q
Surgical treatment of long metatarsal
A
o Metatarsal osteotomy
14
Q
Indications for metatarsal osteotomies
A
- Long metatarsal
- Plantarflexed metatarsal
- Contracted digit that cannot be reduced without decreasing metatarsal length
- Angular deformity of metatarsal
15
Q
Contraindications for metatarsal osteotomies
A
- Pain of unknown etiology
- Parabola correction without underlying pain or symptoms
- Severe osteopenia (really soft bone – difficulty with healing)
16
Q
Most common type of metatarsal osteotomy done
A
Weil osteotomy
Other types
- Plantar condylectomy
- V metatarsal osteotomy
- Dorsiflexory wedge osteotomy
17
Q
Weil osteotomy
A
- Shortening osteotomy which involves a dorsal incision
- Make cut through metatarsal head, parallel to WB surface
- If you have a long metatarsal, it will retract back to the appropriate length
- The head of the metatarsal is usually fixated with 1.5 or 2.0 screw
18
Q
Plantar condylectomy
A
- DuVries initially descripted this procedure
- You shave off the bottom of the condyle on the metatarsal head
- Can lead to arthritis because it cuts into the joint
- Can lead to floating toe due to relaxation of plantar plate
- Used generally for older patients – NOT for active patients
- Good option for diabetic patient with chronic callus/ulcer because
it prevents you from having to remove entire metatarsal head
19
Q
V metatarsal osteotomy
A
- Jacoby initially described this procedure which helps to dorsiflex the metatarsal
- Dorsiflexory osteotomy with little shortening (can create shortening by taking making parallel V cut)
- The toe can be allowed to float (no fixation) - The metatarsal will then seek its own level (a potential complication is delayed healing)
- Can do offset V to help with fixation – You would make one side of the V longer than the other so you have a good spot to place a screw for fixation (an even V is difficult for screw placement)
20
Q
Dorsiflexory wedge osteotomy
A
- Similar concept to Weil, but opposite side of metatarsal (leave the plantar cortex intact)
- Can do proximal or distal (need less wedge if proximal)
21
Q
Metatarsal osteotomy post op protocol
A
General rule of thumb
o If it is a forefoot procedure (distal), you will be WB
o If it is a rearfoot procedure (proximal), you will be NWB
Distal procedures
o WB in postop shoe for 6 weeks if fixated
o If not fixated may consider NWB (don’t want bone floating too much, very large callus)
Proximal procedures
o NWB for 6-8 weeks (how long bone healing takes)
22
Q
Metatarsal osteotomy complications
A
- May lead to “floating toe” (due to tendon/capsule relaxation)
- Transfer lesions (now get problems with the next met down)
- Delayed or nonunions without fixation (uncommon w/ fixation)
23
Q
Freiberg’s infarction
A
- Osteochondrosis or avascular necrosis (AVN) of bone
- Usually involves 2nd metatarsal head
- Excessive loading of metatarsal head compromises circulation to
subchondral bone resulting in AVN and collapse of articular surface - This means the bone dies and the metatarsal head collapses
- Patient experiences tenderness and edema with activity
- Radiographs show nothing early in disease process
- Late stage radiographs show flattening of met head, spurring, sclerosis
24
Q
Radiographs of Freiberg’s infarction
A
- Top left: area of darkness on 2nd metatarsal head
- Top right: area of black at arrow tip, where it should be all bright
- Bottom left and right: after healing has occurred, the entire metatarsal head has flattened out, no cartilage remains
25
Conservative treatment
```
Initial treatment
o Immobilization (boot or cast to prevent pressure with toe-off)
```
Chronic treatment
o Steroid injection
o Rocker bottom shoes (shoe does the work for you, not a lot of pressure with toe off)
o Carbon plate (stiffen shoe, prevents toes from bending or flexing while walking)
26
Surgical treatment of Freiberg's infarction
- Metatarsal head resection (a lot of floating of toe will occur)
- Graft (prevents floating)
- Implant (to resurface metatarsal head)
27
Freiberg's infarction graft
- First remove spurring and contour joint, make room for the graft
- Use orthobiologics or fresh frozen graft
- Orthobiologics provides scaffold for fibrocartilage
- Fresh frozen replaces cartilage
28
Stress fracture
- Pain with palpation dorsally (usually pain plantar in other etiologies)
- Pain with tuning fork application
- May have edema
- X-rays initially negative (may take up to 3 weeks)
- Bone scan (will see uptake in 3rd phase)
29
Stress fracture treatment
- Conservative = Immobilize in boot or postop shoe for 4-6 weeks
- Surgical = Done only if goes to full fracture or excessive callus formation
30
CASE STUDY I
- Biomechanical issues (metatarsus adductus)
- Still a very active person and was in a lto of pain
- Initially had a stress fracture which went onto become a full fracture and non-union
- Took him to surgery
- 3rd metatarsal base was uneven and enlarged, so smoothed it out and removed excess bone
- Place a locking plate to correct fracture site
31
Now we are moving on to soft tissue pathology
FYI
32
Neuroma
- Burning pain
- Tingling/numbness
- “Wrinkled-sock” sensation (something under there)
- Sharp and/or radiating pain
- Symptoms worse with shoes (particularly tight fitting)
33
Diagram of neuroma anatomy
- Medial and lateral plantar nerves branch in the plantar foot
- Come together in 3rd intermetatarsal space, so there is a little bit extra nerve here
- If this gets irritated or becomes enlarged, it can start to cause problems for people
- If you are going to go in and surgically excise it, need to know the anatomy in the area
- The deep transverse intermetatarsal ligament runs across entire ball of the foot and nerves sit right underneath that
34
Intermetatarsal neuroma frequency of interspace involvement
- This chart combines 4 different studies regarding the interspace most commonly involved in neuroma formation
- The third interspace is by far the most common location of a neuroma (64-91%)
- If someone has these symptoms in the 1st or 4th interspace, be cautious of calling it a neuroma because it is so rare
- If someone has these symptoms in the 2nd interspace, thing about a plantar plate tear because that is much more common in that location
- ***NOTE: 3rd interspace (between 3rd and 4th metatarsal)***
Chart is included in handout
35
Neuroma exam
- Pain will be present on direct palpation to the interspace
- Usually NO edema is present
- “Mulder’s sign”: squeeze forefoot while applying plantar and dorsal pressure, palpable click
- Gauthier test: pain with just squeezing foot
36
Neuroma diagnostic testing
- Usually not necessary
- X-rays – to look for stress fracture or Sullivan’s sign (splaying of the toes where the neuroma is)
- Ultrasound – ovoid mass with hypoechoic signal (can actually see the neuroma)
- MRI – best seen on T1 (such a small structure, so may not be able to see it)
37
Neuroma conservative treatment
- Wider shoes
- Metatarsal pad
- Steroid injection – usually inject only 1-2 mL of fluid total since it is a small space, only an 11-47% success rate, avoid doing too much due to risk of atrophy of soft tissue structures
- Sclerosing injection
38
***4% alcohol sclerosing injections*** - solution
Solution: prepare in office
o 48ml of 0.5% bupivacaine HCl with EPI (1:200,000)
o 2mL of dehydrated alcohol for injection
39
***4% alcohol sclerosing injections*** - injection
o Inject just proximal to the “bulb”
o Repeat every 5-10 days – TIME COMMITMENT
o Up to 7-9 injections
o Dockery had 89% success rate (usually around 60-70% success rate)
40
***4% alcohol sclerosing injections*** - Notes
- Not a lot of long-term follow-up regarding recurrence
| - Essentially you are trying to kill the nerve so you don’t have to go in and surgically remove it
41
Other conservative treatment options for neuroma
- Vitamin B12 injection (calms down nerve)
- Phenol (more caustic, meaning able to burn or corrode organic tissue by chemical reaction, but has the same effect as alcohol sclerosing)
42
Morton’s neuroma surgical incisions
- A = Plantar approach, straight linear
- B = Plantar approach, transverse (avoid WB surface)
- C = Dorsal approach, distally
- D = Dorsal approach, overtop nerve
43
Morton’s neuroma surgery
- The nerve branches to the toes are clamped and severed
| - The abnormal nerve is dissected free
44
Advantages and disadvantages of dorsal incision
Advantages
o Immediate weightbearing
o No plantar scar
Disadvantages
o Need meticulous dissection (hematoma formation or hammertoes if not careful)
45
Advantages and disadvantages of plantar incision
Advantages
o Better visualization
o Less incidence of hematoma and hammertoe formation
Disadvantages
o Need to be NWB 3 weeks
o Potential plantar scar
46
Metatarsal osteotomy complications
- May lead to “floating toe” (due to tendon/capsule relaxation)
- Transfer lesions (now get problems with the next met down)
- Delayed or nonunions without fixation (uncommon w/ fixation)
47
Freiberg's infarction
- Osteochondrosis or avascular necrosis (AVN) of bone
- Usually involves 2nd metatarsal head
- Excessive loading of metatarsal head compromises circulation to
subchondral bone resulting in AVN and collapse of articular surface
- This means the bone dies and the metatarsal head collapses
- Patient experiences tenderness and edema with activity
- Radiographs show nothing early in disease process
- Late stage radiographs show flattening of met head, spurring, sclerosis
48
Radiographs of Freiberg's infarction
- Top left: area of darkness on 2nd metatarsal head
- Top right: area of black at arrow tip, where it should be all bright
- Bottom left and right: after healing has occurred, the entire metatarsal head has flattened out, no cartilage remains
49
Conservative treatment
```
Initial treatment
o Immobilization (boot or cast to prevent pressure with toe-off)
```
Chronic treatment
o Steroid injection
o Rocker bottom shoes (shoe does the work for you, not a lot of pressure with toe off)
o Carbon plate (stiffen shoe, prevents toes from bending or flexing while walking)
50
Surgical treatment of Freiberg's infarction
- Metatarsal head resection (a lot of floating of toe will occur)
- Graft (prevents floating)
- Implant (to resurface metatarsal head)
51
CASE STUDY surgery
o Went in surgically, had very large neuroma – 3 cm in length
o Following surgery, foot looks relatively normal, splaying decreased
52
Stress fracture
- Pain with palpation dorsally (usually pain plantar in other etiologies)
- Pain with tuning fork application
- May have edema
- X-rays initially negative (may take up to 3 weeks)
- Bone scan (will see uptake in 3rd phase)
53
Stress fracture treatment
- Conservative = Immobilize in boot or postop shoe for 4-6 weeks
- Surgical = Done only if goes to full fracture or excessive callus formation
54
CASE STUDY I
- Biomechanical issues (metatarsus adductus)
- Still a very active person and was in a lto of pain
- Initially had a stress fracture which went onto become a full fracture and non-union
- Took him to surgery
- 3rd metatarsal base was uneven and enlarged, so smoothed it out and removed excess bone
- Place a locking plate to correct fracture site
55
Now we are moving on to soft tissue pathology
FYI
56
Neuroma
- Burning pain
- Tingling/numbness
- “Wrinkled-sock” sensation (something under there)
- Sharp and/or radiating pain
- Symptoms worse with shoes (particularly tight fitting)
57
Diagram of neuroma anatomy
- Medial and lateral plantar nerves branch in the plantar foot
- Come together in 3rd intermetatarsal space, so there is a little bit extra nerve here
- If this gets irritated or becomes enlarged, it can start to cause problems for people
- If you are going to go in and surgically excise it, need to know the anatomy in the area
- The deep transverse intermetatarsal ligament runs across entire ball of the foot and nerves sit right underneath that
58
Intermetatarsal neuroma frequency of interspace involvement
- This chart combines 4 different studies regarding the interspace most commonly involved in neuroma formation
- The third interspace is by far the most common location of a neuroma (64-91%)
- If someone has these symptoms in the 1st or 4th interspace, be cautious of calling it a neuroma because it is so rare
- If someone has these symptoms in the 2nd interspace, thing about a plantar plate tear because that is much more common in that location
- ***NOTE: 3rd interspace (between 3rd and 4th metatarsal)***
Chart is included in handout
59
Neuroma exam
- Pain will be present on direct palpation to the interspace
- Usually NO edema is present
- “Mulder’s sign”: squeeze forefoot while applying plantar and dorsal pressure, palpable click
- Gauthier test: pain with just squeezing foot
60
Neuroma diagnostic testing
- Usually not necessary
- X-rays – to look for stress fracture or Sullivan’s sign (splaying of the toes where the neuroma is)
- Ultrasound – ovoid mass with hypoechoic signal (can actually see the neuroma)
- MRI – best seen on T1 (such a small structure, so may not be able to see it)
61
Neuroma conservative treatment
- Wider shoes
- Metatarsal pad
- Steroid injection – usually inject only 1-2 mL of fluid total since it is a small space, only an 11-47% success rate, avoid doing too much due to risk of atrophy of soft tissue structures
- Sclerosing injection
62
***4% alcohol sclerosing injections*** - solution
Solution: prepare in office
o 48ml of 0.5% bupivacaine HCl with EPI (1:200,000)
o 2mL of dehydrated alcohol for injection
63
***4% alcohol sclerosing injections*** - injection
o Inject just proximal to the “bulb”
o Repeat every 5-10 days – TIME COMMITMENT
o Up to 7-9 injections
o Dockery had 89% success rate (usually around 60-70% success rate)
64
***4% alcohol sclerosing injections*** - Notes
- Not a lot of long-term follow-up regarding recurrence
| - Essentially you are trying to kill the nerve so you don’t have to go in and surgically remove it
65
Other conservative treatment options for neuroma
- Vitamin B12 injection (calms down nerve)
- Phenol (more caustic, meaning able to burn or corrode organic tissue by chemical reaction, but has the same effect as alcohol sclerosing)
66
Morton’s neuroma surgical incisions
- A = Plantar approach, straight linear
- B = Plantar approach, transverse (avoid WB surface)
- C = Dorsal approach, distally
- D = Dorsal approach, overtop nerve
67
Morton’s neuroma surgery
- The nerve branches to the toes are clamped and severed
| - The abnormal nerve is dissected free
68
Advantages and disadvantages of dorsal incision
Advantages
o Immediate weightbearing
o No plantar scar
Disadvantages
o Need meticulous dissection (hematoma formation or hammertoes if not careful)
69
Advantages and disadvantages of plantar incision
Advantages
o Better visualization
o Less incidence of hematoma and hammertoe formation
Disadvantages
o Need to be NWB 3 weeks
o Potential plantar scar
70
Images of procedure
Image 1
o Traditional technique of flexor digitorum longus tendon transfer
o Tendon has been harvested at the proximal interphalangeal joint level,
split and brough around the diaphysis of the proximal phalanx
o A simultaneous arthrodesis of the proximal IPJ will further facilitate
plantar stabilization of the digit via flexor digitorum longus and brevis
Image 3
o At the top you can see the flexor tendons running along the toe
o In the middle you can see that you drill a hole, take you longus
and pass it up through the proximal phalanx then suture it down
on the dorsal aspect to pull the toe down
71
Cryogenic denervation
- Minimally invasive
- Temp -50°C to -70°C
- Get Wallerian degeneration of axons and myelin, leaving perineurium and epineurium intact (helps prevent stump neuroma)
- Results not permanent
- Can’t use on large neuromas
72
Post-surgical sensory deficit
- You are removing the nerve, so the patient can get
numbness instead of pain in that area
- Sometimes the numbness can go away after time
(other nerves pick up the slack)
- Half of one toe and half of the neighboring toe will lose
sensation
73
CASE STUDY
- 60 year old female
- History of mass left 3rd interspace
- PMH: lupus, Raynaud’s
- Was told by others is was a rheumatoid nodule
- Patient having pain and would like it removed
74
CASE STUDY MRI results
o Dark signal between 3rd and 4th digits
o Large gray mass
o Monochromatic and uniform, so not
concerned about malignancy
75
CASESTUDY surgery
o Went in surgically, had very large neuroma – 3 cm in length
o Following surgery, foot looks relatively normal, splaying decreased
76
Plantar plate pathology
- 2nd MPJ most common site
- Pain worse with walking, better with rest
- Feels like walking on “stone bruise” or “lump”
- Patient may note change in position
77
Etiology of plantar plate pathology
- Long second/short first
- Trauma (not common)
- 1st ray hypermobility (COMMON)
- Hypermobility disorders (i.e. Marfan’s or Ehlers-Danlos) – COMMON
- Overloading (equinus, high heels)
78
Physical exam for plantar plate pathology
- Pain with palpation directly plantar at joint line (more pain at base)
- Focal edema over the joint
- Possible loss of purchase of toe
- Vertical stress test (positive with 2 mm or more displacement
when stabilizing metatarsal head and moving base of proximal phalanx)
- Always do exams bilaterally
79
Positive vertical stress test
- Positive vertical stress test results with dorsal translocation of the proximal phalanx
- Note maintenance of the toe parallel to the plantar aspect of the foot while the maneuver is performed – examiner must be careful not to confuse dorsal translocation with dorsiflexion
80
YU AND JUDGE CLASSIFICATION OF PLANTAR PLATE PATHOLOGY
This is what we are moving onto now... Stages I, II and III of predislocation
81
Predislocation stage I (Yu and Judge)
- Subtle, mild edema dorsal and plantar to lesser MPJ
- Exquisite tenderness plantar and distal to joint
- Alignment of the digit clinically and radiographically appears unchanged compared to contralateral digit
82
Predislocation stage II (Yu and Judge)
- Moderate Edema
- Noticeable deviation of the digit both clinically and radiographically
- Loss of toe purchase, noticeable in weight bearing
83
Predislocation stage III (Yu and Judge)
- Moderate Edema
- Noticeable deviation of the digit both clinically and radiographically
- Loss of toe purchase, noticeable in weight bearing
84
Plantar plate – Diagnostic studies
- X-rays
- Arthrogram
- Bone scan
- MRI
85
Arthrogram
.5-1mL of iodinated contrast injected into joint under fluoroscopy
- With tear or rupture will see contrast tracking up flexor tendons
- Not a common test – mostly for academic study
86
Bone scan
Plantar plate tear
- Positive for phase II (blood pool phase)
- Negative for phase III (bony phase)
Stress fracture
- Can be +/- for phase II (blood pool phase)
- Positive for phase III (bony phase)
87
Notes on bone scan
- If you have a plantar plate tear, it is only a soft tissue abnormality, so you will only see uptake on phase II, nothing on phase III
- For stress fracture, you see some uptake on phase II due to swelling, but full uptake on phase III
88
MRI results
- Lateral aspect of plate of the 2nd MPJ can be disrupted with edema
- Flexor tendon can be disrupted with edema
- White areas where it should just be black
89
Conservative treatment for plantar plate tears
- Metatarsal pads
- Budin splint
- Cross over taping
- NSAIDs
- Ice
- Stiff soled shoes
- CAM boot immobilization (if severe)
90
Surgical treatment for plantar plate tears
- Direct repair or indirect stabilization (flexor tendon transfer)
- PIPJ fusion often done with above procedures to enhance stabilization
- May also need to do metatarsal osteotomy if metatarsal is long
- Limited studies done on 2nd MPJ fusion
91
Direct repair
- Usually done through plantar approach
- Tear is usually off of phalanx side
- You can suture end-to-end or use an anchor into the proximal phalanx base
- If done plantarly, you will need to be NWB for 3 weeks
- Stabilized with K-wire for 4 weeks
- Can also go through dorsal approach if metatarsal osteotomy performed
92
Indirect repair - flexor tendon transfer
- Can do with or without plantar plate repair
| - Can be dorsal or plantar - If dorsal can WB in postop shoe, If plantar NWB for 3 weeks
93
Technique for flexor tendon transfer - indirect repair
Several techniques
o Isolate tendon and split in half, bring up over toe and suture to itself and periosteum dorsally
o Isolate tendon and insert into bone and secure to itself, periosteum or use anchor
94
Images of procedure
Image 1
o Traditional technique of flexor digitorum longus tendon transfer
o Tendon has been harvested at the proximal interphalangeal joint level,
split and brough around the diaphysis of the proximal phalanx
o A simultaneous arthrodesis of the proximal IPJ will further facilitate
plantar stabilization of the digit via flexor digitorum longus and brevis
Image 3
o At the top you can see the flexor tendons running along the toe
o In the middle you can see that you drill a hole, take you longus
and pass it up through the proximal phalanx then suture it down
on the dorsal aspect to pull the toe down
95
CASE STUDY III
- 41 year old female who is a runner presents with burning pain between 2nd and 3rd toe, says it feels like balled up sock under her foot
Previous treatment
o Steroid injection
o Custom orthotics
o Little relief with either
96
CASE STUDY III physical exam
o Positive vertical stress test
o Negative Mulder’s sign
o Pain with direct palpation of plantar 2nd MPJ
o Swelling around MPJ
o Functional hallux limitus present (when I moved her MPJ, her hallux moved fine during NWB, but if you tried it during WB, it just locked up)
MRI – plantar plate tear on lateral part of joint
97
CASE STUDY III treatment
o Dancer’s pad added to orthotic (metatarsal pad with cut out for 1st ray – helps to bring the 1st metatarsal down to avoid the limitus)
o Mobic 7.5 mg
o Discussed possible surgical options
o Flexor tendon transfer with possible plantar plate repair, PIPJ fusion, shortening metatarsal osteotomy
98
CASE STUDY III follow up
4 moths post-op
o Pain resolved plantar PIPJ
o 2nd toe floating
o Pain under 3rd metatarsal head when barefoot
