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 sheath Paratenon has visceral and parietal layers Allows for 1.5cm of tendon glide

Anatomy Paratenon Anterior – richly vascularized The remainder – multiple thin membranes

Anatomy Blood supply Musculotendinous junction Osseous insertion on calcaneus 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 stress Exercise induces tendon diameter increase Inactivity or immobilization causes rapid atrophy Age-related decreases in cell density, collagen fibril diameter and density Older athletes have higher injury susceptibility

Biomechanics Gastrocnemius-soleus-Achilles complex Spans 3 joints Flex knee Plantar flex tibiotalar joint Supinate 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 Physical Partial Localized tenderness +/- nodularity Complete Defect Cannot heel raise Positive Thompson test

Achilles Tendon Rupture Diagnostic Pitfalls 23% 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 dependent Best to measure thickness and gap Good screening test for complete rupture

Imaging MRI Expensive, not dynamic Better 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 CAM Walker or cast with plantarflexion q 2 wks Cast in Plantarflexion 2 wks 4 weeks Allow progressive weight-bearing in removable cast Start physio for ROM exercises When WBAT and foot is plantigrade 2- 4 weeks Start a strengthening program Remove cast and walk with shoe lift. Start with 2cm x 1 month, then 1cm x1 month then D/C

Surgical Management Preserve anterior paratenon blood supply Beware of sural nerve Debride and approximate tendon ends Use 2-4 stranded locked suture technique May augment with absorbable suture Close 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 lift Cast applied in OR 2 wks Touch WB 2 weeks Allow progressive weight-bearing in removable cast Start physio for ROM exercises. No active plantarflexion When WBAT and foot is plantigrade 2- 4 weeks Start a strengthening program Remove cast and walk with a 1cm shoe lift x 1 month then D/C.

Surgical Management: Post-op Care Early functional treatment versus early immobilization in tension of the musculotendinous unit after Achilles rupture repair: a prospective, randomized, clinical study. Kangas J et al. J Trauma. 2003 Jun;54(6):1171-80; discussion 1180-1. 50 pts had repair of Achilles rupture 25 25 Casted in neutral x 6 weeks. WBAT at 3 weeks Immediate active ROM from PF to neutral. WBAT at 3 wk Two re-ruptures One deep infection Same satisfaction Better calf strength only for first 3 months. One re-rupture

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 Casted x 8 wks Surgery + Early functional rehab in brace 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