Dislocations

Question 1

PIP joint dislocation

Answer 1

stability of the PIP joint over boxlike complex

volar plate with checkrein ligaments and collateral ligaments with the proper collateral ligamant and the volar accessory component

components of injury:

collateral ligemant sprain (Verstauchung)

volar plate avusion

central slip disruption

fracture dislocation

impacted fracture dislocation

lateral real true radiographs are most important

v-sign is predictable for incongruence of the PIP joint (dorsal subluxation)

Question 2

clinical evaluation

Answer 2

finger block and evaluate:

1. • the active statbility
2. • the passive stability

classification:

grade I

pain but no laxitiy

grade II

laxity but a firm endpoint, stable are of motion

grade III

grossly unstable, no firm endpoint

simple strains are treated with buddy taping (grade I instability) and early range of motion

Question 3

dorsal dislocation of the middle phalanx

Answer 3

hyperextension with some axial load - typical in ball sports - colleteral ligaments are intact and the volar plate is sheared off.

normally small avulsion at palmar lip - the greater the axial load the greater is the fragment

normally the volar plate ruptures DISTALLY - rarely it ruptures PROXIMALLY and become interposed between the condyles and the base of the middle phalanx - UNREDUCABLE

dislocation classification:

type I

hyperextension deformity with joint surfaces still touching

type II

bayonet position (first a little extension to mobilized the volar plate and bring is back to the volar position - if not a reducible dislocation becomes irreducible)

type III

fracture dislocation

if the joint is stable after reduction - than buddy taping and early range of motion

if unstable a dorsal splint +10° is applied to the position when is becomes unstable - than weekly progress of 10° to normal - goal is to have the patient out of the splint in 3 weeks or sooner

if more than 30° of flexion is needed to get a stable joint surgery is needed

6 month of occasional pain and stiffness - dayly exercise is needed to achieve full range of motion

surgery:

volary - Brunner exicsion - inspection of the A3 pulley and flexor tendons, extraction of the volar plate - first attempt should be a minimal incision to the dorsal PIP joint through the lateralband and the central slip to push the volar plate maybe out of the joint

Question 4

lateral dislocations of the middle phalanx

Answer 4

rupture of one collateral ligament and a partial rupture of the volar plate

more than 20° of dislocation ofter reduction means complete rupture of the collateral ligament - if possible buddy taping an early range of motion

irreducible lateral dislocation show the interposition of the lateral band intraoperative

open repair does not improves healing and motion - if the joint can be hold stable with a buddy tape no surgery is done - stiffness is common problem after PIP joint ligament surgery

Question 5

volar dislocations of the middle phalanx

Answer 5

rare injuries

pure volar luxation or with rotation because a collateral ligament ruptures - so it subluxates to the opposite site

sudden torque to the digit - spinning clothes dryer

condyles ruptures through the extensor mechanism usually between the central slip and the ipsilateral lateral band - reposition in flexion of the MCP joint to relax the intrinsics

volar fracture dislocation should be treated with open reduction and fixation for early motion of the joint - screws have to be in the bone!!! - smaller fragements but intact central slip are splinted for 3 weeks in extension than early range of motion exercises

careful examination is important get the right diagnosis for a volar luxation with a damage to the volar plate, the collateral ligament and the dorsal extensor mechanism

if there is a lag in extension after closed reduction a splint for 6 weeks is used like a boutonniere deformity - open reduction only if there is something trapped to miss a closed reduction or if the radiograph is not congruous

dorsal approach to the joint - repair needs a zone III repair protocol - if the lateral band is ragged better to excise the band

Question 6

fracture-dislocation of middle phalanx dorsal

Answer 6

stable fracture dislocation

volar fragment < than 40% of the joint surface and a concentric joint after reduction - dorsal portion of the collateral ligaments remains attached to the middle phalanx

40% rough guideline - clinical evaluation and experience leads to the right diagnosis

Eaton classification:

Type I - less than 40% - stable - only hyperextension no bajonet dislocation - minimal avulsion fragment - after reduction complete stable

Type II - like Type I - with complete dorsal luxation and bajonet dislocation - less then 40% of joint surface keeps the joint in stable

Type I and Type II usually conservatively with dorsal splinting in 30° and less of 10° weekly processed - full stable extension in 3 weeks - range of motion exercises are performed with the splint in position - active and passive motion proofed over time - volar fragment may become trapped within the flexor sheath and inhibit motion - test the congruency under fluoroscopy - if positive V-sign - there is NO congruency

Type III - like Type II with more than 40% of the joint surface - no collateral ligament stays dorsally with the middle phalanx - complete unstable - no joint support remains (bony and ligamenteous) - open reduction and fixation - maybe hemihamate transplantation

pilon fractures:

maybe only one condyle - so special radiographs or CT - anterior based fractured should adressed volarly - lateral impressions about midline approach

Question 7

surgery for PIP joint fracture-dislocations and pilon fractures

Answer 7

treatment maybe conservatively if there is a stable joint in less than 30°

therefore extension block splinting can be use or an extension block pinning

dynamic skeletal traction

30 - 50% of the joint surface, can be combined with volar plate arthroplasty or hemihamate for joint support motion, technique is known, elevation of the hand - begin exercises passive and active - radiographics ofter 1 and 4 weeks - if bone healing is achieved removal of the fixateur - good results with removing after 4 weeks - after putting the fixateur try to reduce the comminuated fragments percutaneously

Open reduction and internal fixation

through a lateral or volar approach - A3 pulley is excised or reflected - approach through the flexor sheath and the accessory collateral ligament - immediate active range of motion - gutter splint with PIP joint maintained in near full extension

hemihamate autografting

better in cases of comminution to protect the joint from reluxation - difficulte to do - gunshot opening with removal inzision of the palmar plate distally - cleaning of the comminution fracture and measuring - graft is harvest from the hamate to reconstruct the joint - edges of the palmar plate are surured

postop:

splinting in 20° - MP in flexion - after 2-4 days a dorsal block splint in 20° flexion is put to the PIP - active and passive excises with bringing the fingertip to the palm - splint is removed after 4 weeks - than dynamic splinting to achieve full extension

cerclage wiring

only with minimal subluxation but an immense comminution - volar plate deattached and 50% of the collateral ligament - shotgun open the joint - wire put around the bone and is carefully drilled - v-shaped wedge is removed to avoid bulking - lateal edges are repaired - after 2-4 days of edema control - active and passive motion - dynamic splinting are added after 2 weeks

volar plate arthroplasty

collateral ligaments are excised over volar approach, only volar most can be remained - after removing from loose bodies in the joint the volar plate is moved distally and than sutured through the bone in the defect of the volar joint - cover the condyles of the proximal phalanx - sutures are placed in 30° DIP joint flexion - now the joint becomes stable with good congruence - lateral the volar plate is sutured to the remaining collateral ligament - K-wire in a position of 20-30° flexion as temporary transfixation

postop. care:

DIP motion after the surgery, K-wire remove 3 weeks after surgery, unrestricted active motion after 4 weeks, sports 8 weeks with buddy taping, buddy taping is continued over 4-6 month - it may take 6-8 month to achieve final range of motion

literature is optimistic - but not the only perferred technique

Question 8

chronic PIP joint fracture dislocation

Answer 8

costal cartilage and perichondrium (perichondrial arthroplasty)

DIP joints are use

toe IP joints has also been reported

athroplasty and arthrodesis possible, but not not good for young patients

in this case treatment with a volar plate arthroplasty - complete resection from the colleteral ligaments is necessary - lengthening of the checkrein ligaments is necessary to achieve a good position of the volar plate to the comminuation side of the middle phalanx

hemihamate arthroplasty can be used too

Question 9

chronic PIP subluxation (Hyperextension)

Answer 9

type I: dislocation

can be lead to a swan neck deformity

1. laxity of the palmar plate
2. extensor mechanism imbalance

hold the PIP in extension or minimal flexion and let the patient actively extend the DIP joint

if there is a lag in extensioni - there is an imbalance of the extensor mechanism

if there is normal extension than the volar plate is lax

difficult to treat - direct sutures to the volar plate - reattachement of the accessory ligament to the volar plate

best method is a lateral band tenodesis - ulnar-sided mid-lateral incision (lumbricale undisturbed) - mobilize the lateral band from its dorsal attachement - put the PIP joint in 20-30° and suture the lateral band to the A3-Pulley

postop: block splint in 10 to 20° - after 3 weeks can come out of the splint with resting posture in 5° flexion - unrestricted motion is permitted at 6 weeks - unlimited sport after 8 to 10 weeks - buddy taping for 3 month

Question 10

PIP contracture

Answer 10

open release

brunner style - maybe a midline approach - full release of all structures - volar plate (checkrein ligaments) - proper collateral ligaments and accessory ligaments - maybe flexor tendon release - in long standing PIP contractures tradeoff of FDS - maybe skin flaps for covering

postop:

full splinting in extension for 2-3 days - static splinting between exercises for 4-6 weeks - than nighttime splinting for 3 months

Question 11

DIP and IP joints

Answer 11

anatomy is analoug to the PIP joint

dislocation not so frequent - usually dorsal or lateral

instability after pure dislocation is rare - immobilization in slight flexion using a dorsal splint for 2-3 weeks

if reducible the volar plate is interposed

(flexor tendon, fracture fragment, a sesamoid bone) - avulsion of the FDP has to be reattached

if more than 40% of the joint surface is avulsed - than volar plate arthroplasty or closed reduction and pinning

volar dislocations are seldom - mallet injuries and require splinting in full extension for 6 weeks followed by progressive mobilization

Question 12

MCP joint dislocation

Answer 12

relative rare because of their intrinsic ligamentous structure surrounding structures including flexor and extensor mechanism

increasing length of collateral ligaments from extension to flexion - have to be splinted in at least 50° of flexion to maintain length

anatomy

dorsally loose insertion of the common extensor tendon

volarly is the volar plate which is continued to the deep transverse metacarpal ligaments

volar plate has a thick distal portion and thin membraneous proximal portion - no strong checkrein ligaments

linked ligament-box support from one MP joint to adjacent ones

collateral ligaments are more taut in flexion than in extension because of the cam effect created by the nos-spheric shape of the metacarpal head

best stabilization from proximal phalanx base to metacarpal head at about 70° flexion

Question 13

dorsal MCP joint dislocation

Answer 13

relative uncommon injuries - mostly the index finger followed by the small finger

forced hyperextension - volar plate ruptures and inposed between the metacarpal head the base of the proximal phalanx - because of the cam effect normally the volar plate can not be removed because of tightining elements around the metacarpal head

volar plate, A1 pulley, flexor tendons lumbricals and (ADM and FDM in small finger) are involved

volar plate dorsally - flexor tendon dorsally with tight tendon noose - index finger lumbrical tendon radially and flexor tendons ulnarly - flexor tendons are also drawn taut by the dorsally displaced volar plate and pulley

be careful to make a incomplete dislocation not to a complete dislocation

Question 14

simple MCP joint subluxation

Answer 14

volar plate is draped over the metacarpal head - proximal phalanx is locked in 60 - 80° hyperextension

careful wrist in flexion to relax the flexor tendon - than careful pressure to the proximal phalanx volarly - proximal phalanx glides back over the head into reduced position - early range of motion with a dorsal block splint to prevent extension beyond neutral

Question 15

complex MCP joint dislocation

Answer 15

presentation with the MCP joint in extension - no flexion is possible - mildly deviated - metacarpal head can be touched in the palm

radiographs with AP, lateral and Brewerton view AP with 60° MCP flexion and the x-ray beam is tilted 15° ulnar-to-radial direction

surgery:

volarly or dorsally - be careful in the volar approach - the metacarpal head lays in the subcutaneous fat and the vessels are directly beneath the skin - reduction can easily be achieved by release of the A1-pulley

postop: immobilize in 30° flexion for 2 weeks

begin active motion with extension block at 10° for more 2 weeks

buddy tape for 8 weeks

unlimited use after 12 weeks

Question 16

volar MCP joint dislocations

Answer 16

very rare - dorsal capsule may become interposed between the metacarpal head and the proximal phalanx

distal insertion of the volar plate or collateral ligaments or both can be avulsed and become locked between the head and the proximal phalanx

mostly closed reduction - if irreducible than open reduction through a dorsal approach

Question 17

isolated RCL Rupture of the MCP joint

Answer 17

common in athletes

passive MP flexion causes pain - ulnar deviation shows intability and forces pain

grade I and II heal with splinting

initial splinting in 30° degree of flexion for 3 weeks and buddy strap

stable MP joint could have pain for 1 year

grade III

4 weeks of splinting or with surgery

dorsal radial incision - dorsal incision of the extendor hood and mobilization of the ruptured ligament - bone debridement to bleeding - than refixation with a bone achor - tensioned the ligament in a position of 45° flexion - immobilization in 45° for 5-6 weeks

in chronic situations maybe augmentation or arthroplasty - better is arthrodesis in 25° flexion for better grip pinch

Question 18

locked MCP joint

Answer 18

normally a restriction of collateral ligaments over the metacarpal head because of impalement of the ligaments on marginal degenerative osteophyte

long finger mostly affected very prominent radial condylar margin that entraps the RCL

1. insufflation with saline of the joint
2. acutely flex the joint
3. radial deviation and externally rotation to disengage the entrapped ligament
4. gently extend the digit

extension splint for 1 week

Question 19

Thumb MCP joint

Answer 19

radial condyle has a greater dorsal-palmar height than the ulnar condyle which allows a little bit of conjuct rotation with flexion of the finger

complex arrangement of capsular, ligamenteous and musculotendinous structures

anatomy like the PIP joint with no flexor sheat proximal to the volar plate and no strong checkrein ligaments

Question 20

acute UCL injury

skier’s thumb

Answer 20

fall to the outstreched hand with the thumb abducted

associated injuries include tears of the dorsal capsule, rupture of the ulnar aspect of the volar plate, rent (Riss) in the adductor aponeurosis

proximal phalanx rotates volarly to the side ot the tear

UCL tear - thumb rotates in supination around the RCL

avulsion at the ulnar proximal phalanx of more than 10% need fixation of the fragment

Stener lesion

with major radial angulation the UCL ruptured distal and the realigned adductor aponeurosis swipes the distal ruptured UCL proximal - therefore the aponeurosis becomes interposed between the ruptured ligament stumps - a conservative treatment is not possible

testing in flexion is very important because in extension the volar plate gives full lateral stability

radiographs before testing in LA - radial deviation and palmar subluxation acquires surgery

ultrasound can be used and MRI is used in the modern times with a good sensitivity - but very expensive

we use a comparison of the MCP under flouroscopy to the contralateral side - no endpoint an difference about 15° is an indication for surgery - less than 30° laxity in flexion

grade I and II:

immobilization in a splint for 4 weeks - than additional 2 weeks with begin of active motion excercise

grade III:

surgery refixation with pull-out sutures or better bone anchors after the bone has been debrided

after refixation:

1. suture placed between the volar portion of the ligament repair and the volar plate to reconstruct the 3-dimensional complex
2. tear repair of joint capsule
3. gentle radial stess is applied to test the stability

postop:

thumb cast with mobile IP-joint to protect extensor tendon adhesion, cast mobilization for 4 weeks, than costum fabricated splint for additional 2 weeks with active exercises 4 times a day, no splinting longer than 6 weeks - restricted use for 3-4 month - no force - tenderness and thickening about 1 year after surgery

80-90% of early motion can be achieved - sports after 4 month

most common complication is the neuropraxia of the crossing branches of the dorsal sensory branch of the radial nerve

Question 21

chronic UCL injury

gamekeeper’s thumb

Answer 21

historically from scottish gamekeepers who break the neck of rabbits between thumb and index finger - leads to chronic instability

pain, swelling and weakness, resting posture to volar and radial deviation, osteoarthritis

surgery:

maybe direct repair is possible, tendon graft or arthrodesis with osteoarthritis, after 6-12 weeks direct repair is impossible

repair with a tendon graft with the reconstruction of both ligamentous part - pull out suture from ulnar to radial metacarpal head - tension has to be proofed and adjusted - fixation of the joint in 20° of flexion with a k-wire for 4 weeks and splinted 2 weeks longer

avoid radial stess for at least 12 weeks

Question 22

radial collateral ligament injuries

Answer 22

abductor aponeurosis is broad and covers most of the radial side ot the thumb

adduction or torsion with the thumb in flexion - mostly attenuated in the mid-portion

evaluation is the same as the UCL - division of the abductor aponeurosis and repair of the RCL - Stener lesion are not known

chronic instability can be treated with tendon transfer

Question 23

MCP joint dislocation

Answer 23

mostly dorsally, hyperextension with resulting in volar plate rupture and rupture of the collateral ligaments

often reducible - hyperextension and dorsal pressur to the proximal phalanx

FPL - remains with tendon sheath and creating a noose ulnarly around the metacarpal head with a radially displaced thenar intrinsic musculature

if surgery dorsal or volarly or lateral approach - volarly is best because all ruptured elements can be seen and sutured if necessary

closed reduction successful

dorsal splinting in 10° more as the instablility position - when grade II 4 weeks of immobilization

Question 24

chronic volar instability of the thumb MCP joint

Answer 24

may be a manifestion of systemic conditions such as:

• collagen vascular disease
• congential or acquired paralytic disorders
• collapse deformity secondary to CMC joint arthritis
• trauma

reattachement of the volar plate more proximal to a decorticated retrocondylar fossa with a bone anchor

RCL is sutured to the volar plate

transfixation of the joint for 4 weeks with a cast - mobile IP-joint - addtional 2 weeks after k-wire removal and active range of motion exercises

sesamoid arthrodesis is possible with patients of osteoarthritis of the CMC joint (6 weeks of immobilization with free IP-joint)

Question 25

CMC joint

Answer 25

concavoconvex contours give a bit of stability - joint support by ligaments and capsule play the principal role

4 ligaments:

• volar (anterior oblique)
• intermetacarpal
• dorsal-radial
• dorsal oblique (posterior oblique)

volar oblique ligament and dorsal-radial ligaments are the important ligaments for luxation

strauch and collegues concluded the the dorsal-radial ligement has to be ruptured for a complete dislocation - the volar ligament is weaker and can not resist dislocation

rare dislocation mostly dorsally

different types of instability difficult to examine

partial tears could be treated with a thumb splint in palmar abduction-extension for 4-6 weeks, good radiographs have to be made for successful reduction

is the joint sloppy surgical reduction is indicated - closed reduction and two k-wires with the metacarpal in extension and abduction, one k-wire axial - the other k-wire oblique - when the reduction is made and k-wire is drilled pressure from dorsal to the volar metacarpal beak to bring it to the beak ligament

stays unstable than WAGNER approach - a proximal harvest half of the FCR is used to reconstruct the volar beak ligament by a transossar canal in the plain of the thumb nail - after that the CMC joint is pinned - not suture with excessive tension, after 4 weeks with a cast and k-wire gently motion exercises are started - long time of hand therapy - at least about 12 weeks for full use