Flexor Tendons - Zones

Extensor Tendons Zones

Diagnosis of Flexor Injury Normal cascade Independent testing of FDS & FDP Passive tenodesis test Forearm compression test

Flexor Tendon Testing

Normal Flexion Cascade

Tenosynovitis Anatomy Flexor sheaths are closed spaces Extend from the mid-palmar crease to the DIPJ ( Prox edge of A1 pulley to distal edge of A5 pulley) Flexor sheath of small finger is continuous proximally with the Ulnar Bursa, while the sheath of the thumb is continuous with the Radial Bursa Radial & Ulnar bursae extend proximal to the TCL and connect with the Parona space ( Potential space between FDP & PQ muscle )

Tenosynovitis General Flexor sheath infections most often as a result of penetrating trauma – More likely at joint flexion creases – Sheaths are separated from skin by only a small amount of subcutaneous tissue here Also, Felons can rupture into the distal flexor sheath Usual causative agent: S. Aureus most commonly affected digits: – Ring, long & index fingers

Tenosynovitis General Purulence within the sheath destroys the gliding mechanism, rapidly creating adhesions that lead to loss of function destroys the blood supply producing tendon necrosis

Tenosynovitis Clinical Kanavel’s 4 cardinal signs: – Tenderness over & limited to the flexor sheath – Symmetrical enlargement of the digit (“fusiform”) – Severe pain on passive extension of the finger (> proximally) – Flexed posture of the involved digit Not all four signs may be present early on Most reliable sign: pain w. passive extension Cellulitis of the hand may appear similar, but swelling & tenderness is not usually isolated to a single digit

Tenosynovitis Treatment Early infection < 48 hrs (& usually lacking all 4 signs) may initially be treated with IV Abx, splinting & elevation – Failure to respond within 24 hrs. should necessitate drainage Established pyogenic tenosynovitis is a surgical emergency – Requires prompt surgical drainage – Delays may result in tendon &/or skin necrosis