The Bone School

Anatomy

 

Gastrocnemius tendon 10-25 cm long

- soleus 3-10 cm

- inserts superior calcaneal tuberosity

- fibres spiral 90°

- fibres that lie medially in proximal portion become posterior distally

- allows elastic recoil & energy storage

 

Plantaris present in 90% population

- medial to T Achilles

 

Poor blood supply midportion

- mesotenal vessels

- fewest at 2-6 cm

- other blood supply from osseous insertion

 

Epidemiology

 

Usually age > 40 years

- M:F = 12:1

- occasional sportsman

- 75% during sports

 

Aetiology

 

Calf contraction with forced dorsiflexion in setting of tendon degeneration

 

Combination of

 

1.  Repetitive microtrauma

2.  Hypovascularity

- occurs at watershed of vascular supply 

- an area of hypovascularity 5 cm proximal to tendon insertion

 

Factors

- corticosteroids - oral or injected

- anabolic steroids

- flouroquinolone / ciprofloxacin

- gout

- hyperthyroidism

- tendinitis

- cavus foot

- varus foot

 

Mechanical Overload

- footwear (low heel, inadequate shock absorption)

- sudden training increase

- cross training

 

Classification of Tendon Inflammation

 

1. Paratenonitis 

- inflammation of paratenon

- swelling, pain, crepitation, tenderness, warmth

 

2. Paratenonitis with tendinosis

 

3. Tendinosis 

- intratendinous degeneration due to atrophy

- aging, microtrauma, vascular compromise

- swelling absent

- +/- palpable nodule

 

Rupture Site

 

1.  Watershed area

- 5 cm proximal to insertion

- most common

 

2.  Insertion

- common with insertional tendonitis

 

3.  Musculotendinous juntion

- avulsion of medial or lateral head

- may present with chronic weakness

 

 

NHx (if neglected)

 

Weakness / wasting

- difficulty with push off

- compromised running / jumping / stairs 

- can still walk with use of FHL / FDL / T posterior / Peroneals

 

 

History

 

Sudden pain in calf

- with audible snap

- on unaccustomed exercise

- especially tennis / squash

 

Examination

 

Palpable gap

 

 

Weak PF

- unable to perform single heel raise 

 

Positive Thompson Test

- patient prone

- squeezing calf doesn't produce plantarflexion of ankle

 

 

Chronic tear

- gap fills with scar tissue

- gap not palpable

- excessive DF compared with other side

 

 

Ultrasound

 

Cheap, dynamic, fast

- operator dependant

- check reduction of tendon ends with plantarflexion

 

 

MRI

 

Indication

- incomplete rupture 

- signs of degeneration

- measurement of gap in chronic cases / information for reconstruction

 

 

Operative v Non-operative Management

 

Issues

 

1.  Complications 

- infection & skin necrosis with operative

- ? re-rupture with non operative

 

2.  Function

- strength & patient return to activity / sports

- ? better function with non operative

 

Kellam meta-analysis 

 

Operative

- 1% rupture in operative

- 85% return to pre-injury activity level

- 95% satisfied with treatment

 

Non Operative

- 18% rupture

- 70% return to pre-injury activity level

- 65% satisfied with treatment

 

Moller et al JBJS Br 2001

- 112 patients randomised non-operative & operative

- non-operative 20% rerupture & 3% complication rate (all minor)

- operative 2% rerupture & 25% complication rate (all minor)

 

Willits et al JBJS Am 2010 

- 144 patients randomised trial operative v non operative

- concept of accelerated functional rehabilitation in both groups

- 2 weeks NWB

- weight bear in aircast with 2 cm heel raise up to 8 weeks

- able to actively DF / PF below neutral

- no significant difference in rerupture rate or loss of motion / power

 

Non-operative

 

Indications

- elderly, DM, PVD, smokers

- non athlete

 

Technique

 

Equinus front slab 

- need to do within 24 hours

- try to close gap before haematoma forms

- change to full cast at 1 week

- debatable if need long leg cast v short leg

- 2 weeks

 

Functional Rehabilition

- heel raise 2 cm and air cast

- FWB for further 6 weeks

- active ROM below neutral

 

 

Results

 

Rerupture

- rate unknown

- likely in order of 5%

- likely some minimall loss of plantarflexion strength

 

No risk of infection / wound breakdown

 

Operative

 

Indication

- young, active

- athlete 

 

Technique

 

Timing

- ? delay for one week to allow swelling to reduce

 

Position

- prone

- prep both feet to check tension

 

Posteromedial approach

- avoids sural nerve and short saphenous vein

- don’t place scar directly posteriorly / less scar discomfort

- full thickness skin to paratenon

 

Open paratenon and dissect off tendon

- want to repair at end of case on dorsum of tendon

- this reduces skin adhesions

- incise paratenon in the midline anteriorly / increases tissue available for closure

 

Tendon repair

- Bunnell Suture with No 2 Ethibond

- one in proximal and one in distal tendon ends

- tie via two knots with foot fully plantar flexed

- augment with circumferential  4.0 prolene to minimise bunching

 

Augmentation

- not usually needed acutely

 

Paratenon repair

- closure posteriorly to aid glide

- prevents adherence to scar

- use 3.0 vicryl

 

Careful skin closure

- LA with adrenalin

- front slab short leg

 

Post operative

- accelerated rehab as above

- jog at 3/12

- sports at 6/12

 

Complications

 

Wound breakdown

 

Debride, manage infection

- vac dressing

- free muscle flap (usually gracilis) + SSG

- fasciocutanous flap (radial or lateral thigh) has better wear characteristics

 

Rerupture

 

Case 1

 

Previously non operative management / new onset severe pain with bump

- intrasubstance / incomplete tear

 

  

Case 2

 

Acute pain 8 weeks post non operative management rupture

- ultrasound demonstrates scar tissue

- no reduction with plantarflexion

 

 

Reconstruction / Augmentation

 

Indication

 

Unable to primary repair / chronic setting

 

 

Algorithm

 

< 3cm 

- turndown

 

3 - 5 cm 

- VY lengthening

 

 

> 5 cm 

- FHL / FDL / peroneal transfer

- free gracilis graft

- allograft

 

 

Large gaps

- turndown + FHL

- FHL is most accessible / directly medial to T achilles

 

Techniques

 

VY advancement

 

Turndown / Bosworth technique

 

Harvest central third fascia

- from musculotendinus junction as far proximal as possible

- leave attached distally, detach proximally

- closure fascia above

- tubularise fascia with 2.0 ethibond

- drill hole through calcaneal tuberosity

- pass through calcaneum

- suture to itself

 

Can reinforce with plantaris / FHL / FDL / PB

 

 

FDL / FHL transfer

 

Medial foot incision

- harvest tendon

- suture distal FDL stump to FHL

 

Medial calf incision

- pull tendon through

- through drill hole in calcaneum

- pass tendon through and suture to itself

 

 

Peroneus brevis transfer

 

Lateral incision

- divide tendon

 

Standard Posteromedial calf incision

- pass through calcaneal drill hole

 

Augment with plantaris if needed

 

Free Gracilis tendon transfer