Achilles Tendon Disorders

Daniel Penello

Foot & Ankle Rounds

Anatomy

Largest tendon in the body

Origin from gastrocnemius and soleus muscles

Insertion on calcaneal tuberosity

Anatomy

Lacks a true synovial sheathParatenon has visceral and parietal layersAllows for 1.5cm of tendon glide

Anatomy

ParatenonAnterior – richly vascularizedThe remainder – multiple thin membranes

Anatomy

Blood supply1) Musculotendinous junction

2) Osseous insertion on calcaneus

3) Multiple mesotenal vessels on anterior surface of paratenon (in adipose)

– Transverse vincula Fewest @ 2 to 6 cm proximal to osseous insertion

Physiology

Remarkable response to stressExercise induces tendon diameter increase Inactivity or immobilization causes rapid

atrophyAge-related decreases in cell density,

collagen fibril diameter and densityOlder athletes have higher injury

susceptibility

Biomechanics

Gastrocnemius-soleus-Achilles complexSpans 3 joints

Flex kneePlantar flex tibiotalar jointSupinate subtalar joint

Up to 10 times body weight through tendon when running

Achilles Tendon Rupture

Pathophysiology Repetitive

microtrauma in a relatively hypovascular area.

Reparative process unable to keep up

May be on the background of a degenerative tendon

Achilles Tendon Rupture: Textbook Facts

Antecedent tendinitis/tendinosis in 15%

75% of sports-related ruptures happen in patients between 30-40 years of age.

Most ruptures occur in watershed area 4cm proximal to the calcaneal insertion.

Achilles Tendon Rupture

History Feels like being kicked in the leg Case reports of fluoroquinolone use, steroid

injections Mechanism

Eccentric loading (running backwards in tennis) Sudden unexpected dorsiflexion of ankle (Direct blow or laceration)

Physical Exam

Prone patient with feet over edge of bed

Palpation of entire length of muscle-tendon unit during active and passive ROM

Compare tendon width to other side

Note tenderness, crepitation, warmth, swelling, nodularity, palpable defects

Achilles Tendon Rupture

PhysicalPartial

Localized tenderness +/- nodularityComplete

DefectCannot heel raisePositive Thompson test

Achilles Tendon Rupture

Diagnostic Pitfalls23% missed by Primary Physician

(Inglis & Sculco)

Tendon defect can be masked by hematoma

Plantar-flexion power of extrinsic foot flexors retained

Thompson test can produce a false-negative if accessory ankle flexors also squeezed

Imaging

Ultrasound Inexpensive, fast,

reproducable, dynamic examination possible

Operator dependentBest to measure thickness

and gapGood screening test for

complete rupture

Imaging

MRIExpensive, not

dynamicBetter at detecting

partial ruptures and staging degenerative changes, (monitor healing)

Management Goals

Restore musculotendinous length and tension.

Optimize gastro-soleous strength and function

Avoid ankle stiffness

Conservative Management

Cast in Plantarflexion CAM Walker or cast with plantarflexion q 2 wks

2 wks

Allow progressive weight-bearing in removable cast

Remove cast and walk with shoe lift. Start with 2cm x 1 month, then 1cm x1 month then D/C

4 weeks

Start physio for ROM exercises

When WBAT and foot is plantigrade

Start a strengthening program

2- 4 weeks

Surgical Management

Preserve anterior paratenon blood supply

Beware of sural nerveDebride and approximate tendon endsUse 2-4 stranded locked suture

techniqueMay augment with absorbable sutureClose paratenon separately

Surgical Management

Bunnell Suture

Modified Kessler

Many techniques available

Surgical Management : Post– op Care

Assess strength of repair, tension and ROM intra-op.

Apply cast with ankle in the least amount of plantarflexion that can be safely attained.

Patient returns to fracture clinic 2 weeks post-op.

Variations in Post-op Protocols

Functional Bracing

Post- Op Care

Cast applied in OR Remove sutures, apply a walking cast with heel lift2 wks

Allow progressive weight-bearing in removable cast

Remove cast and walk with a 1cm shoe lift x 1 month then D/C.

2 weeks

Start physio for ROM exercises. No active plantarflexion

When WBAT and foot is plantigrade

Start a strengthening program

2- 4 weeks

Touch WB

Surgical Management:Post-op Care

J Trauma. 2003 Jun;54(6):1171-80; discussion 1180-1. Kangas J et al.

Early functional treatment versus early immobilization in tension of the musculotendinous unit after Achilles rupture repair: a prospective, randomized, clinical study.

50 pts had repair of Achilles rupture

Casted in neutral x 6 weeks. WBAT at 3 weeks

Immediate active ROM from PF to neutral. WBAT at 3 wk

Better calf strength only for first 3 months.

One re-rupture

Two re-ruptures

One deep infection

Same satisfaction

25 25

Conservative vs Surgical

Acute rupture of tendon Achillis. A prospective randomised study of comparison between surgical and non-surgical treatment.Moller M, et al. J Bone Joint Surg Br. 2001 Aug;83(5):863-8

112 patients

Surgery +

Early functional rehab in brace

Casted x 8 wks

21 % re-rupture 1.7% re-rupture

5% infection

2% Sural nerve inj.No difference in functional outcome

Summary of Pooled Outcome Measures

Risk of Re-Rupture

Surgery = 68% risk reduction for re-rupture