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 (especially elderly)
- gout
- hyperthyroidism
- tendinitis (10% ruptures have preexisting achilles tendon disorder)
- cavovarus OR planovalgus 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
MAJOR SIGNS (AAOS Clinical Practice Guidelines 2010)
Positive Thompson Test (90% sensitivity and specificity)
- patient prone
- squeezing calf doesn't produce plantarflexion of ankle
Palpable gap (70% Sensitivity and Specificity)
MINOR SIGNS (more difficult to elicit acutely)
Weak PF
- unable to perform single heel raise
Increased DF comparted to contralateral side
Chronic tear
- gap fills with scar tissue
- gap not palpable
- excessive DF compared with other side
Xray
Only indicated if associated bony tenderness
Ultrasound
Cheap, dynamic, fast
- operator dependant
- check reduction of tendon ends with plantarflexion
MRI
Indication
- incomplete rupture
- signs of degeneration
- clinical uncertainty (two major signs not present)
- measurement of gap in chronic cases / preoperative planning 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
Meta-analysis
Khan et al JBJS Am 2005
- 12 trials involving 800 patients
- operative treatment associated with lower RR (.27; CI .11 - .64) of rerupture
- higher risk of complications (RR 10.6; CI 4.82 – 23.2)
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 at all time indices
- 13 complications in operative versus
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 minimal 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 / Krackow suture x 2 with high strength suture / fibre wire
- 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
Infection
Swab, washout, primary closure
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