Overview Sagittal band (SB) rupture leads to leads to dislocation of the extensor tendon and may be caused by trauma or by a chronic inflammatory process such as rheumatoid arthritis. when it is caused by trauma it is also known as a "boxer's knuckle". acute traumatic injuries are treated with splinting where chonic injuries often require surgical reconstruction. Science Epidemiology demographics more common in pugilists index and middle finger in professionals ring and little finger in amateurs location the middle finger is most commonly involved index 14% middle 48% ring 7% little 31% the radial SB is more commonly involved radial:ulnar = 9:1 Mechanisms traumatic forceful resisted flexion or extension laceration of extensor hood direct blow to MCP joint atraumatic inflammatory (e.g. rheumatoid arthritis) spontaneously during routine activities Associated conditions MCP joint collateral ligament injuries Anatomy Extensor mechanism comprises tendons EDC/EIP/EDM lumbricals interossei retinacular system sagittal bands the sagittal bands are part of a closed cylindrical tube (or girdle) that surrounds the metacarpal head and MCP along with the palmar plate origin volar plate and intermetacarpal ligament at the metacarpal neck insertion extensor mechanism (curving around radial and ulnar side of MCP joint) retinacular ligaments triangular ligament Sagittal band function the SB is the primary stabilizer of the extensor tendon at the MCP joint juncturae tendinum are the secondary stabilizers resists ulnar deviation of the tendon, especially during MCP flexion prevents tendon bowstringing during MCP joint hyperextension biomechanics ulnar sagittal band partial or complete sectioning does not lead to extensor tendon dislocation radial sagittal band distal sectioning does not produce extensor tendon instability complete sectioning leads to extensor dislocation sectioning of 50% of the proximal SB leads to extensor tendon subluxation extensor tendon instability after sectioning is greater with wrist flexion instability after sectioning is greater in the central digits (than border digits) the least stable tendon is the middle finger the most stable tendon is the little finger junctura tendinum stabilize the small finger Classification Rayan and Murray Classification of Closed SB Injury Type Description Image Type I SB injury without extensor tendon instability Type II SB injury with tendon subluxation Type III SB injury with tendon dislocation Presentation Symptoms pain MCP soreness swelling focal MCP swelling or tenderness snapping senstion with extension Physical exam tendon snapping ulnar deviation of the digits at the MCP joint (rheumatoid arthritis) inability to initiate extension can hold MCP in extension once placed there unable to extend finger from flexed MCP position (causes tendon to subluxate) pseudo-triggering - key to recognize to avoid unnecessary trigger release surgery this is the snapping that takes place from subluxation and relocation extensor tendon dislocation into intermetacarpal gully most unstable during MCP flexion with wrist flexed least unstable during MCP flexion with wrist extended provocative test pain when extending MCP joint against resistance (with both IP joints extended) Imaging Radiographs required views hand PA, lateral, oblique optional view Brewerton view AP with dorsal surface of fingers touching the cassette and MCP joints flexed 45deg stress view to rule out collateral ligament avulsion/injury findings exclude mechanical/bony pathology limiting extension, or predisposing to sagittal band rupture may show dropped fingers and ulnar deviation in rheumatoid arthritis Ultrasound (dynamic) indications when swelling obscures the physical exam findings subluxation of EDC tendon relative to metacarpal head on MCP flexion MRI indications to establish diagnosis of SB disruption (radial or ulnar SB) may show underlying etiology e.g. synovitis in rheumatoid arthritis views axial images at the level of the long MCP with MCP joint flexed for maximum EDC tendon displacement findings poor definition, focal discontinuity and focal thickening in acute injury subluxation of extensor tendon in radial direction due ulnar SB defect dislocation of extensor tendon into ulnar intermetacarpal gully radial SB defect Differentials MCP joint collateral ligament injury EDC tendon rupture Trigger finger Junctura tendinum disruption Congenital sagittal band deficiency MCP joint arthritis Treatment Nonoperative extension splint or yoke splint for 4-6 weeks indications acute injuries (within one week) Operative direct repair (Kettlekamp) indications chronic injuries (more than one week) where primary repair is possible professional athlete extensor centralization procedure (realignment) indications chronic injuries (more than one week) where primary repair is NOT possible professional athlete Techniques Extensor Centralization Procedures (Realignment) anesthsia local approach dorsal incision reconstruction (various techniques described) trapdoor flap ulnar based partial thickness capsular flap created tendon placed deep to flap flap resutured to capsule Kilgore tendon slip distally based slip of EDC tendon on radial side looped around radial collateral ligament sutured to itself after tensioning to centralize tendon Carroll tendon slip distally based slip of EDC tendon on ulnar side routed deep to affected tendon and around radial collateral ligament sutured to itself after tensioning to centralize tendon McCoy tendon slip proximally based slip of EDC tendon looped around lumbrical insertion sutured to itself after tensioning to centralize tendon Watson EDC tendon transfer distally based slip of EDC tendon slip looped under deep transverse metacarpal ligament weaved to remaining EDC tendon after tensioning to centralize tendon Wheeldon junctural reinforcement for a middle finger radial SB rupture, the juncturae tendinum (JT) of the ring finger is divided close to the ring finger, bring JT over the extensor tendon attach JT to the torn SB fascial strips or free tendon graft rehabilitation Complications MCP flexion contracture usually from non-operative treatment or delayed presentation secondarily intrinsic tightness develops
QUESTIONS 1 of 3 1 2 3 Previous Next (OBQ12.262) A 28-year-old NFL running back complains of continued hand pain three days following an injury sustained while being tackled. He was splinted on the field. He has tenderness over the long finger metacarpal head, with subluxation of the extensor tendon into the intermetacarpal area during active metacarpophalangeal joint flexion. A representative MRI is shown in Figure A. What is the next best step in management of this patient? Review Topic QID: 4622 FIGURES: A 1 Observation alone 1% (36/3704) 2 Continued splinting in flexion 1% (38/3704) 3 Continued splinting in extension 15% (562/3704) 4 Open repair of the disrupted junctura tendinae 6% (232/3704) 5 Open repair of the disrupted sagittal band 76% (2818/3704) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 5 (OBQ06.92) A 20-year-old man has pain, swelling, and popping over his index metacarpophalangeal joint after striking a wall 3 days ago. Radiographs are normal, but physical exam reveals a palpable defect over the dorsum of the joint with clenching of the fist, and this defect is resolved with extension of the metacarpophalangeal joint. What is the next most appropriate step in treatment? Review Topic QID: 203 1 Trigger finger steroid injection 1% (16/2948) 2 Extension splinting of the metacarpophalangeal joint 60% (1755/2948) 3 Metacarpophalangeal synovectomy 1% (22/2948) 4 Extensor hood reconstruction 39% (1135/2948) 5 Metacarpophalangeal joint arthrodesis 0% (3/2948) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 2 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
Login to View Community Videos Login to View Community Videos Sagittal Band Rupture David Macknet Hand - Sagittal Band Rupture 1 week ago 106 views Upgrade to View Premium Videos Upgrade to View Premium Videos Watson technique Colin Woon Hand - Sagittal Band Rupture 5/5/2013 1527 views Upgrade to View Premium Videos Upgrade to View Premium Videos Repair of the sagittal band centralizing the extensor tendon Michael Hughes MD Hand - Sagittal Band Rupture 1/23/2013 1326 views See More See Less
? congenital absence of sagittal band bilateral ulnar three fingers (C1606) Hand - Sagittal Band Rupture HPI - patient noticed it when sound became more audible more 4 ms whats diagnosis 8/28/2013 55 0 0