Extensor Mechanism The Stiff Hand: Boutonniere & Swan Neck • Central slip inserts into base of the middle phalanx • Lateral bands lie dorsal to the PIP joint center of rotation Sylvia Dávila, PT, CHT San Antonio, Texas • Lateral bands secured palmarly by the transverse retinacular ligaments & dorsally by the triangular ligament

Boutonniere Deformity Extensor Mechanism

• Disruption or lengthening of • Central slip inserts into central slip base of the middle • Lateral bands slip volar to phalanx PIP axis of motion & act as • Lateral bands lie dorsal flexors to the PIP joint center of rotation • Lateral bands secured palmarly by the transverse retinacular ligaments & dorsally by the triangular ligament

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Pathomechanics of Elson’s Test

• Flex PIP to 90 degrees over edge of table • Disruption of central slip • Patient attempts to extend PIP • Lateral bands migrate palmar to axis of • (A) With an intact central slip there is good extensor rotation of PIP due to tone at the PIP & little extensor force at DIP attenuation of triangular ligament • Overpull through the lateral bands due to volar position • Exaggerated extension pull of DIP & flexion of PIP

Elson’s Test

• (B) With central slip disruption there is decreased extensor force at PIP & prominent extensor tone at DIP • Lateral bands are palmar to axis of rotation

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Boutonniere Injury Pseudo-Boutonniere Management

• Caused by a • Acute or chronic with a hyperextension injury of full passive flexible PIP the PIP resulting in a • Splint PIP joint in full flexion extension full time 6-8 without injury to the weeks central slip • Nighttime splinting for • Lateral band migrate & another 6 weeks tighten & stretch central slip • Over time decreased PIP extension

Boutonniere Injury Pseudo-Boutonniere Management

• No disruption of • Acute or chronic with a extensor mechanism full passive flexible PIP • Elson’s Test: good • Splint PIP joint in full extension force at PIP & extension full time 6-8 little force at DIP weeks • PIP flexion contracture • Nighttime splinting for with flexible DIP another 6 weeks • No contracture of ORL

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Boutonniere Injury Management Boutonniere Deformity Modified Stack Splint PIP Flexion Contracture

• Tight enough to limit PIP flexion & not constrict • Correct PIP contracture • Cut splint at the distal end & trim sharp edge before initiating full time • Pass splint over DIP on to the PIP PIP extension splinting • Secure splint with tape • Dynamic orthosis • Static progressive orthosis

Boutonniere Injury Boutonniere Deformity Management PIP Flexion Contracture

• Active DIP flexion exercise • Correct PIP contracture during full-time extension of before initiating full time PIP PIP extension splinting – Pulls lateral bands dorsal to PIP • Serial casting – Promoting gliding of lateral bands – Stretches transverse retinacular ligaments – Stretches oblique retinacular ligaments preventing hyperextension of DIP

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Boutonniere Deformity Boutonniere Deformity PIP Corrective Orthoses PIP Corrective Orthoses

• Dynamic PIP extension • Joint Jack • Static progressive extension • Best for more unyielding < 35°

Boutonniere Deformity Boutonniere Deformity PIP Corrective Orthoses PIP Corrective Orthoses

• Wirefoam orthosis • Contractures > 35° best • Best for more supple treated with custom contractures < 35° fabricated orthosis • Amount of force & angle more precise

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Boutonniere Deformity Boutonniere Deformity PIP Corrective Orthoses AROM

• Serial casting • Static progressive orthosis

PIP Injury Boutonniere Deformity Rehabilitation AROM

• Active & passive DIP • Adduction with IP flexion with PIP extension extended to stretch • Intrinsic muscle ORL recruitment to direct • Blocking exercise to extension force at PIP maximize DIP capsular motion & glide of extensor & flexor tendons

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Boutonniere Deformity Swan Neck AROM & PIP Corrective Orthoses Pathomechanics of Deformity

• Active motion to redirect • Metacarpal flexion extension fore at PIP • Hyperextension of the • Blocking exercise PIP joint • Relative motion orthosis • Flexion of the DIP joint

M Merritt, JHS, 2014

Boutonniere Deformity Swan Neck PIP Corrective Orthoses Pathomechanics of Deformity

• Relative motion orthosis • Inability to overcome to redirect extension hyperextension of the force at PIP PIP joint • Unable to initiate flexion

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Swan Neck Swan Neck Pathomechanics of Deformity Pathomechanics of Deformity

•RA • Deformity may be • Untreated mallet caused by injury at DIP, deformity PIP or MCP • Volar plate laxity • DIP: mallet injury can • Spasticity lead to swan neck • • Terminal extensor tendon is over stretched • Malunion middle or ruptures phalanx fracture • Strong extensor force at PIP causing hyperextension

Swan Neck Swan Neck Pathomechanics of Deformity Pathomechanics of Deformity

• Volar subluxation of proximal • PIP: Volar plate injury phalanx - central slip tightens causing PIP hyperextension • Hyperextension of PIP • Rupture of terminal extensor due to lateral band tendon displacement • Rupture FDS tendon creating • Minimal pull on terminal flexor/ extensor tendon extensor balance disruption • DIP flexes

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Swan Neck Pathomechanics of Deformity Therapy Guidelines

• FDS rupture or • Address the mechanism lengthened allowing PIP of deformity hyperextension • Corrective orthosis • Intrinsic muscle – to shorten elongated tightness develops structures • Lateral bands snap over – or stretch shortened condyles of proximal structures and phalanx with active prevent deformity flexion

Swan Neck Swan Neck Deformity Pathomechanics of Deformity Therapy Guidelines

• MCP volar subluxation & UD seen in RA • Address the mechanism • Intrinsic muscle tightness of deformity • PIP hyperextension • Corrective orthosis – to shorten elongated structures – or stretch shortened structures and prevent deformity

This presentation is the intellectual property of the author. Contact them for permission to reprint and/or distribute. Swan Neck Deformity Swan Neck Deformity Therapy Guidelines Therapy Guidelines

• Address the mechanism • Stretch contractured of deformity ligament, tendon, or • Corrective orthosis muscle – to shorten elongated • Interosseous muscle structures passive stretch – or stretch shortened • Lumbrical muscle active structures and stretch prevent deformity

Swan Neck Deformity Therapy Guidelines The Stiff Hand: Boutonniere & Swan Neck • Address the mechanism of deformity • Corrective orthosis – to shorten elongated structures – or stretch shortened Sylvia Dávila, PT, CHT structures and San Antonio, Texas prevent deformity

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