Great Toe

Dislocation

Epidemiology

 

Uncommon

- dancers

- athletes

 

Aetiology

 

Hyperdorsiflexion of the MTPJ

 

Pathology

 

MT head dislocates plantar

- may buttonhole through capsule

- can prevent closed reduction

 

Blocks to Reduction

 

1.  Sesamoids

2.  Conjoint tendon

3.  Intersesamoid Ligament

 

Management

 

Closed Reduction

 

Open Reduction

 

Dorsal Approach

- protect dorsal superficial nerve

- divide capsule medial to EHL

- may need to divide intersesamoid ligament

- may need to divide adductor hallucis

 

 

 

Hallux Rigidus

Definition

 

Painful restriction of dorsiflexion of the great toe 

- secondary to degenerative changes in MTPJ

- initially pain and synovitis

- osteophytes don't form medially or on plantar aspect

 

Epidemiology 

 

Two peaks

1.  Adolescence F > M

2.  Middle Age M > F

 

Aetiology

 

Often Idiopathic

 

Trauma

- OCD

- hyperextension injuries

 

Anatomical

- pronated foot

- abnormally long 1st MT

- pes planus

- DF 1st ray

 

Inflammatory

- gout

- CPPD

- inflammatory arthropathy

 

History

 

Pain on walking

- especially slopes & rough ground

- pain may become continuous

 

Numbness 

- compression of dorsomedial cutaneous nerve

 

Examination

 

Shoe shows excessive lateral wear

- toe off on lateral border 

- patient avoids dorsiflexion

 

Look

- hallux is usually straight

- MTPJ is enlarged

 

Feel

- synovial thickening

- palpable dorsomedial osteophyte & bunion 

- altered sensation dorsal toe / due to tethering of dorsomedial nerve by osteophytes

 

ROM

- DF restricted & painful N = 90°

- PF often reduced and painful N = 30°

 

X-ray

 

Changes of osteoarthritis

- dorsomedial osteophyte

- joint space narrowing

 

Great Toe Dorsal OsteophyteHallux Rigidus Dorsal Osteophyte

 

Management

 

Non Operative

 

Options

 

Education & Reassurance

 

Orthotics

- initially stiff soled shoes

- rockerbottom sole

- high toe box

 

NSAID

HCLA

 

Operative

 

1.  Moberg Osteotomy

 

Indication

- young patient with mild OA & > 30° PF

 

Technique

- dorsal closing wedge osteotomy of P1 

- converts PF range into functional DF

 

2.   Cheilectomy

 

Mann 1988 JBJS

 

Concept

- removal of dorsal osteophytes

- increase painless DF range (average 20°)

 

Great Toe Cheilectomy

 

Indication

- for adults with minimal degenerative changes

- normal joint space in plantar half MTPJ

 

Disadvantage

- recurrence of pain

 

Technique

- dorsal incision over MTPJ

- joint incised either side EHL

- synovectomy

- remove ~ 1/3 of dorsal MT head

- remove osteophytes from base of P1

- need DF of ~ 90°

- stiff shoe till ROS

- then flexible sole and ROM exercise

 

3.  Arthrodesis

 

Great Toe MTPJ OAGreat Toe MTPJ Fusion APGreat Toe MTPJ Fusion Lateral

 

Indication

- adults with significant degenerative changes

 

Disadvantage

- lateral transfer metatarsalgia

- IPJ OA

- malposition

- limitation of footwear type

- non-union

 

Technique

- dorsomedial approach

- protect dorsal cutaneous nerve

- mobilise EHL laterally and open capsule

- divide collaterals

- free P1 of soft tissue attachments

- 15° valgus

- 15° DF relative to plantar surface / 20 - 25° relative to metatarsal shaft

- dorsal plate / crossed screws

 

Results

- 30% develop asymptomatic OA IPJ

 

Hallux Rigidus Fusion 2 screws APHallux Rigidus Fusion 2 screws Lateral

 

4.  Interpositional Arthroplasty

 

Indication

- severe OA & moderate demand

- minimal bone resection

 

Technique

- imbricate dorsal & volar capsule into joint space

 

5.  Swanson Arthroplasty

 

Indication

- adults with low demands

 

Disadvantage

- breakage

- silicon synovitis

- very difficult to salvage

 

6.  Keller's Procedure

 

Indication

- for elderly with low demands

 

Disadvantages

- lose windlass mechanism

- transfer metatarsalgia

- cosmetically poor

- drifts into both DF & valgus / Cock Up deformity

 

 

Hallux Valgus

Background

DefinitionHallux Valgus Severe

 

Bunion

- medial prominence of head of 1st MT

 

Hallux Valgus

- medial deviation 1st MT

- lateral deviation of great toe

 

Anatomy

 

Metatarsal head

- has 2 grooves separating ridge (cristae)

 

Sesamoid

- in each tendon of FHB

- sesamoids attach to P1

- no attachment to MT head

- sesamoid ligaments attach to sesamoids and plantar plate

- FHL passes plantar to the plate & between the sesamoids

 

Plantar plate

- formed by

- FHB / Abd. Hall / Add. Hall / Plantar aponeurosis /  capsule

 

Sesamoids and plantar plate stabilised

- abductor hallucis (medial)

- adductor hallucis & trans metatarsal ligament (lateral)

- insert into sesamoids & Base P1

- no muscles insert into head MT

 

Collateral ligaments

- from head of MT to base of P1

- insert into sesamoids

 

Biomechanics

 

Great Toe provides stability to the medial aspect of the foot

 

Windlass mechanism of plantar aponeurosis

- plantar aponeurosis arises from tubercle of calcaneum

- medial slip inserts into base of proximal phalanx via sesamoids

- as body passes over foot, P1 forced into DF & slides over MT head

- plantar aponeurosis winds around MT head & plantarflexes the 1st MT

- creates arch

 

In hallux valgus, windlass is less effective

- results in transfer of weight to lateral aspect of foot

- especially second MT head

 

Blood Supply

 

3 main

- 1st dorsal and plantar metatarsal artery

- superficial branch of medial plantar artery

 

Medial

 

Medial plantar artery

- remains plantar to the MT until the level of the neck when it runs obliquely dorsally

- divides into the medial cervical branch, and the medial sesamoid branch

 

Lateral

 

First plantar MT artery

- is formed by the deep plantar arch and a perforating branch from the DPA

- runs distally in the 1st MT space

- nutrient artery to neck (variable)

- cervico-sesamoid branch (constant)

 

Lateral Cervical branch

- enters plantar surface at base of neck

- supply major part of head

- care in not stripping under the neck to preserve the cervical branch

 

Dorsolateral

- small branch from DPA

- penetrates the dorso-lateral capsule near margin of  articular cartilage

- not big enough to provide sole supply

- can be sacrificed if needed

 

Characteristics

 

Great toe

- lateral deviation of the great toe  (HVA > 15o)

- medial deviation of the first metatarsal  (IMA > 9o)

- +/- subluxation of the first MTPJ

- hallux pronation

- prominent mediation eminence

- sesamoid rotation / uncovering

 

Lesser toes

- overriding of the second toe

- metatarsalgia

- lesser toe hammer & claw

 

Epidemiology

 

Two ages of presentation

 

1.  Adolescent form

- usually bilateral

 

2.  Adult form ~ 50's

- strongly familial

- positive FHx in 2/3

- F > M

- F:M = 9:1 in those needing operations

 

Aetiology

 

Likely multifactorial

 

1.  Shoe Wearing

 

Evidence

- more women are affected

- women's shoes are tight-toed

- unshod 2% vs 33% shod

- unshod toes separate on weight bearing

- in shoes, toes crowded & hallux abducted

 

2.  Hereditary

- usually strong FHx

- tend to present earlier

- AD with incomplete penetrance

- made worse by female's shoe wear

 

3.  Generalised Ligamentous Laxity

- splaying of forefoot

- excessive mobility of 1st TMT

- laxity of medial capsule of MTPJ

 

4.  Anatomical factors

 

Metatarsus Primus Varus

- associated with HV

- especially adolescent variety

 

Metatarsus Varus

 

1st MT

- long / short

- hyper pronated

 

2nd Toe amputation

- loss of lateral support for great toe

 

MTPJ

- rounded joint

 

TMTJ

- hypermobile

- medially slanted

 

Flatfoot

 

Short achilles tendon

 

5.  Pathological Conditions

 

Rheumatoid arthritis

- leads to loss of capsular support

- RA best treated with fusion

 

Neurological conditions

- CP best treated with fusion

 

Pathology

 

A.  Congruent MTP joint

 

Cause

- increased DMAA 

- Hallux valgus interphalangeus

 

Present

- enlarged medial eminence (bunion)

- pressure against shoe

- painful bursa or cutaneous nerve

 

Management

- MTP joint usually stable & won't sublux

- can’t do distal soft tissue release

- will sublux a congruent joint

 

B.  Incongruent MTPJ

 

Hallux Valgus Incongruent Joint, ex

 

Subluxed MTPJ

- usually progressive

 

Origin

- starts with lateral pressure on great toe

- tight high heels

- P1 moves laterally

 

Progression

- PI moves laterally & puts pressure on MT head

- moves it medially, thus increasing intermetatarsal angle

- attenuation of medial joint capsule

- sesamoid sling held in place by ADDH & transverse metatarsal ligament

- MT head moves further medially / varus deformity

- slides off sesamoids

 

Final deformity

- appearance of lateral migration of sesamoids

- however sesamoids maintain constant distance from second MT

- lateral sesamoid lies beside MT head in intermetatarsal space

- ADDH pronates the great toe

- medial extensor hood / capsule stretched

- EHL & FHL comes to lie lateral to MTPJ

- finally, lateral capsular structures become contracted & the deformity becomes fixed

 

C.  Medial Eminence

- MT head changes occur

- groove or medial sagittal sulcus develops at medial border of articular cartilage

 

D.  Bunion

- callosity of skin + bursa

 

E.  Lesser Toes

- MTP less stable & weight transferred to MT 2 & 3 -> callosities

- great toe may drift beneath 2nd toe

- alternatively, 2nd toe may subluxate laterally

- lateral toes become crowded

- often develop claw or hammer deformity

- increased weight bearing through middle MT heads may lead to metatarsalgia

- worse with clawing of lesser toes

 

History

 

Pain

- over medial eminence (75%)

- metatarsalgia under lesser toes

- degeneration of sesamoid joint

- dorsal aspect osteophytes / rigidus

 

Shoe problems

- wide foot

- difficulty fitting shoes

 

Secondary deformity of lesser toes

- especially hammer deformity of the second toe

- rubbing of the PIPJ on shoe

 

Cosmetic appearance

 

Examination

 

Hallux Valgus Clinical

 

Standing

- bunion

- HV

- clawing / hammer toes

 

Assess ROM ankle and STJ

- tight T Achilles

 

Look at wear patterns on foot

- callosities under 2/3 MT head

 

MTPJ

- tender bunion

- painful MTJP

- correctable / ROM correctable

- pain over sesamoids

 

TMTJ

- hypermobility

- > 9mm abnormal

 

Lesser toes

- deformity / correctable

 

Neurovascular examination

           

Weight Bearing AP X-ray

 

1.  Hallux Valgus Angle / MTPA

- metatarso-phalangeal angle

- normal < 15o

 

Hallux Valgus MTPA > 40

 

2.  Intermetatarsal angle/ IMA

- normal < 9o

 

Hallux Valgus Intermetatarsal Angle > 20 degrees

 

3.  Congruence

- place dots

- medial & lateral edges of the articular surfaces of the MT head & P1 base

- assess to see if line up / joint congruent

 

Hallux valgus Incongruent Joint

 

4. Interphalangeal angle

- normal is <10°

- identify hallux interphalangeus

 

5.  DMAA

- distal metatarsal articular angle

- normal < 6o

 

Hallux Valgus Increased DMAA

 

5.  Sesamoid subluxation

- amount of lateral sesamoid uncovered by MT

- medial sesamoid should not cross midline axis of MT

 

Hallux Valgus Lateral Sesamoid Uncovered

 

6.  MTPJ OA

 

7.  Size of the medial eminence

- amount of MT head medial to the line along the medial border of the MT

 

8.  TMT Angle

- medial sloping

 

Hallux Valgus Medial Sloping TMTJ

 

Mann Classification  

 

1.  Congruent

 

2.  Incongruent

 

A.  Mild

 

MTPA < 30°

IMA < 15°

Lateral sesamoid < 50% uncovered

 

Hallux Valgus Mild

 

B. Moderate

 

MTPA 30 - 40°

IMTA 15 - 20o

Lateral sesamoid 50 - 75% uncovered

 

C. Severe

 

MTPA > 40°

IMTA > 20°

Lateral sesamoid > 75% uncovered

 

Hallux Valgus Severe Unilateral

 

3.  Degenerative

 

Hallux Valgus Severe Degenerative

 

Management

Non-Operative

 

Education regarding shoe wear

- extra wide / large toe box

 

Insoles

- longitudinal arch support

- pre MT dome for metatarsalgia

- podiatry to attend to callosities

 

Toe spacers

 

Analgesia

 

Operative

 

Indications

 

1.  Continued pain and discomfort

2.  Difficulties with shoe wear

- split size shoe requirements 

- difficulty fitting shoes

- only 60% wear "fashionable" shoe post-op

3.  Deformity of lesser toes

4.  Skin problems

5.  Cosmetic appearance – relative indication

 

Contra-indications

 

Poor peripheral arterial circulation

Current sepsis

Uncontrolled diabetes

Peripheral neuropathy (relative)

 

Aims

 

1. Correction of the hallux valgus and intermetarsal angles 

2. Creation of a congruent MTP joint

3. Sesamoid realignment

4. Removal of the medial eminence

5. Retention of functional range of motion of the MTPJ

6. Maintenance of normal weight bearing mechanics of foot

 

Surgical Options

 

Congruent

 

1. DMAA  < 15°

- treat hallux interphalangeus

- Akin with exostectomy

 

2. DMAA > 15°

- Chevron with closing wedge

 

Incongruent

 

Mild

- Chevron

- DSTP (Distal Soft Tissue Procedure) +/- proximal osteotomy

 

Moderate

- DSTP & proximal osteotomy

- Scarf

 

Severe

- DSTP & proximal osteotomy

- arthrodesis

 

Rheumatoid

 

Mild to Moderate / Low demand

- arthroplasty

 

Severe

- arthrodesis

 

Hypermobile TMTJ

- fusion (Lapidus) & DSTP

 

Surgical Procedures

 

1.  Chevron

 

Hallux Valgus ChevronGreat Toe Chevron

 

Indications

- incongruent joint

- HVA < 30o / IMA < 15o

- patient < 60 years

 

Technique

 

Avoid lateral release = AVN 40%

 

Approach to Hallux Valgus

 

Dorsomedial approach in internervous plane

- don't go directly medial as will get sensitive scar

- protect dorsal sensory nerve

- distally based "V" capsular flap

- expose MTP joint

 

Exostectomy

- remove medial eminence with saw

- leave 1- 2 mm medial to medial sulcus

- otherwise risk hallux varus

 

60° osteotomy apex distal

- longer plantar limb to avoid sesamoids and inferior joint surface

- apex 1 cm from articular surface

- translate 5mm

- 1mm displacement corrects IM angle 1º

- can perform medial closing wedge to correct DMMA

 

Fixation

- not always necessary

- sutures / k wire / screw

 

Closure

- imbricate capsule

- advance to tighten medially

 

Second toe releases as needed

 

Post op

- bandage / POP to maintain correction

- check wound at 1 week

- bunion boot / heel walk

- toe spacer

- 6/52

 

Hallux Valgus Toe Spacer

 

Results

 

GE 75% if IMA >12° 

GE 95% if IMA <12°

 

Complications

 

AVN is rare

- ensure apex 8-10 mm from articular surface

- avoid DSTP

 

2.  Distal Soft Tissue Procedure

 

Hallux Valgus Pre DSTPHallux Valgus Post DSTP

 

Modified McBride

- release of tight lateral structures (ADDH, lateral capsule, transverse MT ligament)

- medial exostectomy (just medial to sagittal sulcus)

- medial capsular plication

 

(Modification: no longer excise sesamoid)

 

Indications

- mild HV with incongruent joint

- severe HV when combined with proximal osteotomy

 

Technique

 

1.  Dorsomedial approach

- protect nerve

- V shaped capsulotomy

- remove medial prominence

 

2.  Incision first web space

- protect branches of DPN

- insert lamina spreader

- release ADD hallucis at P1

- cut capsule between sesamoid and MT

- divide transverse MT ligament



Results

 

92% good results

 

Complications

 

Nerve injury

- plantar cutaneous nerve

 

Hallux varus

- from releasing lateral FHB from sesamoid

 

3.  Proximal Osteotomy + DSTP

 

Indications

- severe HV

- correct IMA with osteotomy

- correct HVA with DSTP

 

Results

- in combination with DSTP

- GE 90 %

 

Options

- crescentertic

- opening wedge (lengthens)

- closing wedge (shortens)

 

Opening wedge

- extend medial incision

- incomplete ostetomy with saw at base MT

- use bone from bunionectomy to fill gap

- fixation with small plate

 

4.  Scarf

 

Indications

- moderate HV

- see separate technique

- technically challenging but good results

 

5.  Akin

 

Indications

- congruent joint

- DMAA < 15o

- hallux interphalangeus > 10o

- residual HV after other procedures

 

Technique

- medial closing wedge osteotomy of P1

- combine with cheilectomy

 

6.  Keller Procedure

 

Technique

- resection 1/3 of proximal phalanx

- should use pin to stop cock up deformity & to stiffen joint

 

Indications

- housebound / non ambulator

- elderly

- salvage

- marginal circulation - DM / PVD

- hallux rigidus if cheilectomy or arthrodesis contra-indicated

 

Complications

- instability / cock up deformity

- transfer metatarsalgia (in young)

 

Results

- 80% good results

 

7.  Arthrodesis

 

Indications

- hallux valgus with arthritis

- severe hallux valgus

- neuromuscular disease i.e. cerebral palsy

- RA

- salvage procedure for failed procedures

 

Position

- 15º valgus

- DF 10º relative to plantar aspect of foot

- DF 30° relative to ray

 

Technique

- dorsomedial approach

- release EHB / mobilise EHL / release collaterals

- Coughlin male and female reamers

- secure with cross screws or plate

 

Hallux Valgus Arthrodesis

 

8. Lapidus Procedure

 

Hallux Valgus SevereHallux Valgus Proximal Osteotomy and Lapidus

 

Indications

- TMTJ hypermobility

- fusion TMTJ

 

Problems

- difficult to achieve union

- difficult to get position correct

 

Joint multiplanar

- malrotation poorly tolerated

- shortens medial column

- can get metatarsalgia

 

Technique

- slight plantar flexion and lateral deviation

 

Lapidus APLapidus Lateral

 

Complications of Surgery

 

Transfer Metatarsalgia

 

Recurrence

- incorrect surgery

- poorly performed surgery

- high risk groups i.e. adolescent

 

Nerve injury

- dorsal and plantar cutaneous nerve

 

Cock up Toe

 

Cause

- post Keller’s

 

Management

 

Arthrodesis MP joint

- shorten if don't use graft

- fusion rate 95% (BG) vs 70% (no BG)

 

Hallux Varus

 

Cause

- excessive medial resection

- resection of fibular sesamoid

- excessive lateral release or medial plication

 

Clinical

- not always painful

- cosmetically unacceptable

- difficulties with shoe wear

- cockup deformity

- with time stiffens in extension & medial deviation

 

Options

- soft, well fitting shoe

- arthrodesis

- soft tissue reconstruction

 

EHL Reconstruction           

- lateral two thirds of the tendon removed from its insertion

- detached distally, passed under transverse ligament

- inserted into proximal phalanx

 

AVN

 

Rarely seen in Chevron

- due to disruption of volar blood supply

 

Great Toe AVN Post Chevron

 

Management

- arthrodesis / excise avascular fragment and shorten toe

Scarf Osteotomy

Technique

 

A.  Longitudinal Cut

- plantar proximal / dorsal distally

- ends up being parallel to sole

- leave strong plantar portion of head to prevent dorsiflexion

- mark centre of head

- distally to a point 2mm prox and 3mm above the centre of the head

 

B.  Transverse cuts

- plantar proximal / dorsal distal

- angle of 45o with the long cut

- directed slightly proximal (10-15o) to aid displacement

 

Displacement

 

A. Transverse plane

- Primary direction of displacement

- can be up to ¾ of the surface as the strong lateral strut is preserved

- lateral rotation should be avoided as it increases the DMAA

- medial rotation can be used (to improve DMAA) but limits the amount of lateral displacement

 

B. Frontal plane

-  Lowering of the 1st MT head is achieved via the obliquity of the transverse cut

-  It will act to relieve metatarsalgia

 

C. Sagittal plane

- Lengthening can be done but tends to increase soft tissue tension and lead to stiffness

- shortening can be readily achieved by

- increasing the obliquity of the transverse cuts (max shortening 3mm)

- resecting ends of prox  / distal fragments (doesn’t elevate head as II to sole)

 

Fixation

 

Cannulated screws over K wires

 

A. Distal

- start lateral where the bone is string and allows medial resection

- aim obliquely into the MT head

- screw to end 2mm prox to cartilage

 

B. Proximal

- important to respect the lateral part of the fragment to avoid fracture

- aim transverse from dorso-medial to plantar-lateral

 

The corner is then taken off the proximal fragment 

- rounded with rongeurs where bunion has been sliced off

 

 

Ingrown Toe Nail

Onychocryptosis

 

Aetiology

 

Improper nail trimming

Tight shoes & socks

Poor hygiene

Repetitive trauma to distal toe

Curved nail bed in elderly

 

Stages

 

1.  Inflammation

- painful irritation about embedded nail plate in lateral groove

 

2.  Infection

- overt infection with granuloma & discharge 

- starts as serous discharge then purulent

 

3.  Granulation

- stage 1 & 2 + chronic changes

- hypertrophy of lateral wall

- growth of epithelium over chronic granulation tissue 

 

Management

 

Stage 1 

- non-operative

 

Stage 2 

- oral ABx then non-operative

- if fails partial nail avulsion

 

Stage 3 

- often requires partial nail matrix ablation

 

Non Operative

- warm saline soaks x2 /day

- pledget under nail corner

- cleaning of lateral groove

- nail will grow 2 mm /month

- aim for nail plate that protrudes distal to hyponychium

 

Operative

 

1.  Wedge resection

 

Technique

- remove lateral part of nail

- partial ablation of nail matrix

- debulk tissue in lateral fold

 

Post op

- non adherent dressings 48/24 then warm soaks

- open toe box shoe 10/7

- 3-4 weeks before normal shoes again

 

Complications

- recurrence spicules nail plate 

- 5%

 

2.  Zadek's

 

Technique

- removal of nail plate 

- removal of entire germinal nail matrix proximal to lunule

 

3.  Terminal Symes procedure

 

Technique

- amputation of the distal half of the distal phalanx

- good for dystrophic and mycotic nails

- toe end appears bulbous

 

 

 

Juvenile Hallux Valgus

Epidemiology

 

More common in girls

High incidence of positive family history (75%)

 

Can be associated with mild CP

 

Pathology

 

Juvenile Hallux Valgus

 

Congruent joint

- 50% compared with 9% in adult HV

 

Metatarsus primus varus

- increased IM angle

- often the primary deformity

 

Epiphyses usually still open

 

Oblique first TMTJ Angle

 

Ligamentous Laxity

 

Difference from Adult HV

 

Less severe

- no arthrosis

- sesamoid subluxation & pronation less common than in adult

- medial eminence not as prominent

- HVA not as big a contributor

 

Examination

 

Ligamentous laxity

 

T Achilles tightness

 

TMTJ hypermobility

 

Neurological examination

 

X-ray

 

Normal Angles

- HV < 15o

- IMA < 9o

- DMAA < 10o

 

Often DMAA increased

 

Management

 

Non-operative

 

Delay any surgery until

- adolescence

- physis closed (but not CI if open)

 

Well fitting shoes

 

Flexible flat foot may benefit from medial arch support

 

Operative 

 

Aims

- reduce DMAA

- reduce IMA

 

Congruent joint 

- less likely to progress (therefore treat conservatively)

- requires extra-articular realignment

 

Options

 

1.  Double or triple osteotomies

 

A.  Akin / proximal phalangeal osteotomy

- corrects interphalangeal angle

 

B.  Chevron biplanar distal metatarsal osteotomy

- adjust DMAA by adding closing wedge osteotomy

 

C.  Proximal metatarsal osteotomy

- further corrects IMA

 

2.  Hypermobile TMTJ common

- Lapidus procedure

 

Hallux Valgus Lapidus Procedure

 

3.  1st Cuneiform Opening Wedge Osteotomy

- severe IM angle with open 1st metatarsal epiphysis

- marked M-C joint obliquity with high IM angle

- opening wedge (iliac crest graft)

 

Complications

 

20% recurrence rate

- failure to correct IMA

 

Hallux varus 

- split extensor hallucis longus transfer

 

AVN 

- rare even in combined distal procedure

 

 

 

Onychomycosis

Definition 

 

Fungal infection of the nail

 

Epidemiology

 

Toenail affected 4x more common than fingernail

Prevalence has increased x 4 in last 2 decades

 

Aetiology

 

Dermatophytes most common cause

 

99% T rubrum & T mentagrophytes

- destroy nail by chemical or enzymatic process

 

Pathogenesis

 

First

- keratin of hyponychium is infected by the dermatophyte

 

Second

- involves nail bed & nail plate

- initially invades ventral plate which arises from nail bed

- intermediate plate has soft keratin & can become involved

- dorsal nail plate rarely involved

 

Clinical

 

Usually cosmetic problem only

- may become painful

 

Diagnosis

 

Microscopy of nail scrapings & culture studies

-> hyphae

- can culture if necessary

 

Management

 

Non-operative

 

Debride & remove part or all of nail

 

Topical agents less effective than systemic because don't target matrix

 

Oral antifungals 

- griseofulvin & ketoconazole (need up to 1 year of treatment)

- terbinafine (Lamasil) & itraconazole (Sporanox) 

- more effective with shorter treatment (3-6m)

- remain in the nail for 6 months

 

Operative

 

Zadek's

Terminal Syme amputation

 

Sesamoids

Anatomy

 

3 Sesamoids may be present in great toe

- 2 almost always present on plantar aspect of MTPJ

- 1 may be present on plantar aspect of IPJ

 

MTPJ sesamoids most important

- embedded in FHB tendons

- held together by intersesamoid ligament & plantar plate

- each side of crista / inter-sesamoid ridge

- articulate with plantar facets of 1st MT

 

Tibial usually larger than fibula

 

Tibial more impacted in weight bearing than fibula

- higher incidence traumatic injury to tibial

 

Insertions

- FHB

- Adductor hallucis

- Abductor hallucis

- Plantar plate

- Intersesamoid Ligament

- Plantar aponeurosis

 

Orientation

- Proximal to MT head in stance

- Pulled under MT head with DF / toe off

 

Ossification

- between 7-10 years

- often multiple centers 

- may result in bipartite / tripartite appearance

 

Bipartite

- fibular rare

- tibial bipartite in ~ 10% 

- bilateral in ~ 25% of these

- congenital absence - one or both

 

Bipartite Sesamoid

 

Blood Supply

 

Type A 50% medial plantar artery and plantar arch

Type B 25% plantar arch

Type C 25% medial plantar artery

 

Increased risk of AVN if only single vessel into sesamoid

- which is seen in Type C more commonly than B

 

Functions

- absorb weight bearing pressure

- reduce friction

- protect tendons

- act as fulcrum to inc mechanical force of FHB

- Sesamoids and Collats provide medial / lateral stability of 1st MTPJ

 

History

 

Do not always present with symptoms directly referable to sesamoids

- generalized pain around Hallux

- pain after sudden pop or snap after running

 

Pain as hallux extends in terminal part of stance phase

 

Neuralgic symptoms or numbness if digital nerve compressed 

 

Examination

 

Local tenderness

Decreased strength on PF

Pain on passive DF

Loss of active & passive DF

 

Cavus foot

- plantar flexed 1st ray 

- excess axial load on sesamoid

 

Imaging

 

Standard lateral not very useful

- AP, medial oblique, lat oblique, axial

 

Bone scan 

 

Projection important to differentiate sesamoids from MTPJ

- may be obscured by AP scan

- PA or oblique with Collimation useful for DDx

- caution with increased uptake in ~25% of asymptomatic patients

- marked difference to contralateral side significant

 

MRI 

 

Useful for Osteomyelitis

 

CT 

 

Useful for post-traumatic changes 

- compared with contralateral side

 

Conditions

 

1.  Fracture

 

Difficult to differentiate from symptomatic multipartite sesamoid

- especially if fracture through bipartite 

- comparison X-ray with contralateral foot 

- MRI & bone scan with pin hole collimation useful

 

 Fractured SesamoidSesamoid Fracture CT

 

Non operative management

- initial treatment

- orthosis / dancer's pad / cast / MT bar

- especially stress fracture

 

Surgery

- excision of most comminuted fragment or entire sesamoid

- preferred over bone graft in most cases

- consider graft for athletes

 

2.  Osteochondritis

 

Infrequent

- osteonecrosis with regeneration & calcification may be present

- may be enlarged / deformed / sclerotic with mottling / fragmentation

 

3.  Infection

 

Rare except diabetic neuropathy

- Pseudomonas relatively common 

 

4.  Sesamoiditis

 

Repetitive trauma especially teens / young adults

- Inflammation & bursal thickening may be present

 

5.  Osteoarthritis

 

May be in conjunction with MTPJ OA / RA / Gout

 

Management

 

Stiff soled or rocker bottom shoe + MT pad

 

Sesamoidectomy

- may decreases pain

- Don't remove both

- leads to clawing of hallux

 

6.  Intractable Plantar Keratoses

 

Usually caused by

- sesamoid with plantar located osseous prominence

- plantarflexed first metatarsus / cavus

 

Management

 

Intractable lesions

- sesamoid shaving or resection

- avoid shaving if 1st MT is plantarflexed

- consider basilar dorsiflexion osteotomy

 

7.  Nerve Impingement

 

Impingement of medial branch plantar digital nerve on medial sesamoid

 

Sesamoidectomy

 

Principles

 

1.  Never excise both 

- high incidence of Hallux Valgus or Cock Up deformity

2.  Never make incision directly over sesamoid

3.  Always repair adductor if excising lateral sesamoid

 

Produce mechanical defect in FHB unit

- can excise up to 2/3 of either without disturbing ligamentous attachments

- may relieve pain without disrupting FHB mechanism

 

Tibial 

 

Tibial sesamoid excision

- 3cm plantar medial incision

- Medial branch plantar digital nerve identified & retracted

- Locate sesamoid by palpation

- Flex hallux 20-30o & retract FHL

- Incise inter-sesamoid ligament & pull sesamoid medial

- Shell out from capsule & plantar plate with knife

- Imbricate capsule

 

Tibial sesamoid shaving

- Plantar medial approach

- Excise plantar 1/2 with microsagittal saw

- Smooth with rongeur

 

Fibular

 

Approach

- either dorsal or plantar approach

- dorsal demanding due to depth

- plantar - NV bundle & FHL to negotiate  

 

Dorsal incision 

- from 2-3 cm proximal to web space

- Identify & protect branch SPN

- Interval between Adductor Hallucis & joint capsule opened

- Tendon of Add Hallucis reflected from lateral sesamoid

- Grasp sesamoid & divide inter-sesamoid ligament

- Release proximal & distal & excise

- repair adductor

- Close skin 

 

Plantar incision

- Flex hallux

- 4cm incision between MT 1 & 2

- Retract NV bundle either lateral or medial

- Locate FHL & open pulley over it

- Flex hallux to relax FHL & retract medially

- Divide inter-sesamoid ligament

- Excise proximally & distally

- Reattach cuff of FHB

- Consider oblique wire across MTPJ

 

Complications

 

Cock up toe

Hallux valgus or varus

Nerve injury

Fat pad disruption

Painful plantar scar if plantar incision

Turf Toe

Definition

 

Hyper-dorsiflexion injury to 1st MTP joint

 

Management

 

Grade 1 - Mild sprain

 

Symptoms

- minimal swelling / ecchymosis

 

Management

- return to play immediately

- RICE / NSAIDS

 

Grade 2 Partial tear plantar plate

 

Symptoms

- tender / swelling / ecchymosis

 

Management

- return to sport 1-2 weeks

- taping toe to prevent hyper-extension

- stiff soled shoes

 

Grade 3 complete tear plantar plate

 

Symptoms

- marked pain / swelling / ecchymosis / marked decrease ROM

- +/- sesamoid fracture / disruption of FHB

 

Management

- return to sport 3-6 weeks

- surgical removal of loose bodies

 

Unstable

- see proximal displacement of sesamoids

- require operative repair of plantar plate