Dorset County Hospital Orthopaedic Surgeon Sean Walsh · Sean Walsh Orthopaedic Surgeon Dorset County Hospital Southampton Hand Course 28th June 2013 ... But not every alteration

Sean WalshOrthopaedic Surgeon

Dorset County Hospital

Southampton Hand Course 28th June 2013

● Shapes and orientation of articular surfaces● Ligaments● Oblique positioning of scaphoid● Tendons surrounding the joints● Other soft tissues● Peripheral and central nervous system


● Initially synonymous with Malalignment● Diagnosed on plain radiograph● But not every alteration in carpal alignment is

pathological e.g. hyper lax wrists● Redefined as inability to bear physiological loads with

an associated loss of carpal alignment● But some patients are asymptomatic most of time with

well aligned wrists and are able to sustain physiological loads. Symptomatic on specific tasks with typical sensation of “giving way”


● Dynamic instability with sporadic malalignment under certain loading conditions

● Static instability when malalignment is permanent regardless of loading conditions


● Carpal dysfunction● In a normal wrist there is the ability to

transfer loads without sudden changes in stress on the articular cartilage ( normal Kinetics) and the capacity to move throughout the normal range without sudden alterations of intercarpal alignment (normal Kinematics)


● Osseous Anatomy


● Laterally convex distal surface of scaphoid articulates with concavity if trapezium and trapezoid – STT joint

● Central portion – lunocapitate joint● Medial hamate-triquetral articulation helicoid joint (

screw shaped). ● Type I lunate – single facet, Type II an extra facet articulating with hamate


● Tightly packed collagen bundles, mechanically important

● Mechanoreceptors● Proprioception to CNS – dynamic

stabilisation● Wrist proprioception through SLL

needs an intact PIN


● Extrinsic● Palmar radiocarpal, Palmar ulno carpal and

dorsal radio carpal.● There are no dorsal ligaments between the

ulna and the carpus


● Radioscaphoid● Radioscapho-capitate● Long Radiolunate Short Radiolunate


● Ulnar Lunate, Ulnar Triquetrum● Ulnar Capitate


● Dorsal Radial Triquetrum Ligament● Wide fan shaped ligament inserting onto dorsal

rim of triquetrum (deep fibres onto lunate)


Berger R , Ann Plast Surg. 1995 Jul;35(1):54-9.

● Dorsal midpalmar /intercarpal ligament● Dorsal ridge triquetrum, along distal edge lunate,

inserts dorsal rim of scaphoid , trapezium and trapezoid.


● Dorsal and palmar● Connect bones of the same carpal row (palmar and

dorsal interosseous)● Or link the two rows to each other


● 3 distinct structures● Dorsal and palmar SL ligaments, central

fibrocartilaginous membrane


● Palmar and Dorsal● Fibrocartilaginous membrane between ● Palmar Lig. Thicker and stronger 301N


● Distal row is a fixed unit attached to metacarpals● Proximal row functions as an “Intercalated Segment”.● The term ‘intercalated segment’ refers to it being the

part in between the proximal segment of the wrist consisting of the radius and the ulna and the distal segment

● This intercalated segment is the keystone in the coordination of motions of the wrist and in the control of forces that are transmitted from the hand to the forearm and vice versa.


● Wrist radial deviation, scaphoid flexes, lunate flexes.● Wrist ulnar deviation triquetrum extends, lunate

extends● Scaphoid tends to flex, Triquetrum tends to extend and

the lunate follows


● Lunate is influenced by Triquetrum and extends● DISI, Dorsal Intercalated Segmental Instability


● Lunate is influenced by Scaphoid and flexes● VISI Volar Intercalated Segmental Instability● VISI can be normal in a lax wrist


● Scapho Lunate Interosseous Ligament SLIL● Primary stabiliser of the SL joint● SLIL failure force of 300N● Secondary stabilisers● Scaphoid Capitate and STT ligaments● Palmar - RSC, LRL,SRL - stabilise scaphoid ● Dorsal –Dorsal Radio Carpal Ligament, Dorsal Inter

Carpal Ligament● Dynamic stabilisers – Flexor carpi radialis, Extensor

carpi ulnaris


● Wrist Kinematics - how the wrist moves

● Carpal Kinetics – how it sustains physiological loads without giving way

Normal wrist : Perfect interaction between wrist tendons, joint surfaces and soft tissue constraints, allows motion and loading without yielding


● Kinetic Instability - unable to bear physiological loads without yielding

● Kinematic Instability- abnormal movements, click or clunk


Mechanical instability( Kinetic or Kinematic)

+Symptoms

=CLINICAL INSTABILITY


● Four major patterns● Carpal Instability Dissociative (CID)● Carpal Instability Non-dissociative (CIND)● Carpal Instability Complex (CIC)● Carpal Instability Adaptive (CIA)


● Acute● <1 week● Maximum potential to

heal● Sub-acute

● From 1 to 6 weeks● Possible to heal

● Chronic● > 6 weeks● Unlikely to heal


● Pre-dynamic● Dynamic● Static reducible● Static not

reducible


● DISI● VISI● Volar translation● Dorsal translation● Radial translation● Ulnar translation● Proximal translation● Distal translation


● Between bones of same carpal row● Scaphoid-Lunate, Lunate-

Triquetrum ● Capitate-Hamate


● Unstable scaphoid non-union – distal scaphoid follows distal carpal row

● Proximal fragment follows the proximal carpal row● Scapholunate dissociation● Scaphoid rotates around the RC ligament



Extension + Ulnar Deviation +Supination






Yin and Gilula: Imaging of the symptomatic wrist, 2001

● Lunotriquetral dissociation


● Very unusual● Rupture of transverse intercarpal

ligaments binding bones of the distal row

● Dorsopalmar crush or blast injury


● Radiocarpal, between radius and proximal carpal row

● Midcarpal, between proximal and distal rows

● No disruption between the bones of the proximal or distal rows


● Excessive laxity● Rupture of radiocarpal ligaments – carpus

displaced down slope of radius● Rheumatoid arthritis● Madelung’s deformity due to fatigue of

ligaments – excessive shear forces● Trauma- radiocarpal dislocation with or

without radius fracture



● Group of conditions● Dysfunction of the radiocarpal and

midcarpal joints



I. Anterior- entire proximal row flexed on lateral viewII. Posterior-Normal alignment in standard radiographs, dorsal subluxation with dorsally directed force. III. Combined radiocarpal and midcarpal, both joints abnormally subluxable in a palmar and dorsal direction as a result of increased global laxityIV. Adaptive dysfunction secondary to an extra carpal problem – usually a malunited distal radius fracture.

● Attenuation or rupture of triquetro-hamate-capitate, STT and scaphocapitate ligaments

● Often with insufficiency of the dorsal radiocarpal ligament

● Proximal row remains flexed until near the end of ulnar deviation, where it suddenly rotates into extension with a palpable thud.

● “Catch up clunk”● Most cases have combined medial and lateral

insufficiency



● Extra carpal pathology● Dorsally malunited distal radius fracture● Postural adaption of proximal carpal row to

conform to the abnormal radial tilt● Flexed midcarpal joint● Slackening of palmar midcarpal ligaments● Pain , tenderness at midcarpal joint● Improves when radial deformity corrected with an

osteotomy



● CID + CIND● Derangement within same row of carpal

bone● Derangement between rows● Within this category 5 groups of carpal

dislocations have been identified


● Dorsal perilunate dislocations - lesser arc● Dorsal perilunate # dislocation - greater arc● (Extreme wrist extension, ulnar deviation,

midcarpal supination, e.g.motorcycle RTA)● Palmar perilunate dislocations – lesser or

greater arc● Axial dislocations● Isolated carpal dislocations


Greater arc

Lesser arc




● Mechanisms of wrist stability● Definitions of Instability – kinetic and

kinematic● Common instabilities in clinical practice● Carpal malalignment● Classifications of wrist instability


● Carlos Heras-Palou for loan of clinical photographs and videos

● Marc Garcia Elias


QUESTIONS ?


Documents

Dorset County Hospital Orthopaedic Surgeon Sean Walsh · Sean Walsh Orthopaedic Surgeon Dorset County Hospital Southampton Hand Course 28th June 2013 ... But not every alteration