Scapholunate ligament injury

Anatomy

Scapholunate ligament	Scapholunate joint
C shaped 3 components - dorsal ligament: thickness and most important - membranous - volar ligament thickness	Scaphoid and lunate move together - flex with radial deviation - extend with ulna deviation

Scapholunate ligament

Scapholunate joint

C shaped

3 components

- dorsal ligament: thickness and most important

- membranous

- volar ligament thickness

Scaphoid and lunate move together

- flex with radial deviation

- extend with ulna deviation

Pathology

Most injured carpal ligament

FOOSH

- axial loading

- capitate driven into interval between scaphoid and lunate

Dynamic instability	Static instability	SLAC
SL ligament torn Scaphoid and lunate not separated	DISI (dorsal intercalated instability) Takes 3 - 12 months to develop	Arthritic changes Takes 3 - 15 years
Ligament tears - scaphoid most comon - midsubstance - off lunate least common	Scaphoid and lunate separate on xray Scaphoid flexes due to attachment to distal row Lunate extends due to triquetrum attachment	Radial styloid Radio-styloid joint Midcarpal joint as capitate descends into SL gap

Dynamic instability

Static instability

SLAC

SL ligament torn

Scaphoid and lunate not separated

DISI (dorsal intercalated instability)

Takes 3 - 12 months to develop

Arthritic changes

Takes 3 - 15 years

Ligament tears

- scaphoid most comon

- midsubstance

- off lunate least common

Scaphoid and lunate separate on xray

Scaphoid flexes due to attachment to distal row

Lunate extends due to triquetrum attachment

Radial styloid

Radio-styloid joint

Midcarpal joint as capitate descends into SL gap

Examination

Swelling and tenderness over scapho-lunate joint

Scapholunate ballottement

- stabilize scaphoid and lunate

- move them relative to each other

Kirk-Watson test

- thumb on dorsum wrist / index finger on scaphoid tuberosity

- passive ulna deviation: the scaphoid is displaced dorsally over the lip of the radius

- passive radial deviation: scaphoid proximal pole reduces with a clunk

Kirk Watson Test 1 Kirk Watson Test 2

X-ray

Scapholunate gap > 3 mm

AP

Terry Thomas sign	Cortical ring sign	Scaphoid shortened
Increased scapholunate interval > 3 mm compared with other side	End on view of distal scaphoid due to flexion	Shortened due to flexion

Terry Thomas sign

Cortical ring sign

Scaphoid shortened

Increased scapholunate interval

> 3 mm compared with other side

End on view of distal scaphoid due to flexion

Shortened due to flexion

Lateral xray

Increased scapholunate angle > 60^o

- scaphoid flexed & lunate extended

- usually 30 - 60^o

SL angle

Scapholunate angle 80^o

Stress views

Bilateral clenched wrists

- in ulnar deviation

- in radial deviation

clenched fist

CT

sl ct SL CT CT SL

MRI

SL mri SL mri

SL ligament injury with minimal disassociation / SL separation / dynamic instability

SL ligament injury with SL separation and static instability

Increased scapholunate angle

Arthroscopy

Normal scapholunate ligament radiocarpal arthroscopy

Normal scapholunate ligament midcarpal arthroscopy

Torn scapholunate ligament midcarpal arthroscopy

Modified Geissler classification

Grade I: SL ligament attenuation/hemorrhage, no intercarpal incongruency
Grade II: SL ligament attenuation, intercarpal incongruency, 1 mm probe can be passed but not rotated through carpal gap
Grade III: SL ligament attenuation, intercarpal incongruency, 1 mm probe can be passed and rotated through carpal gap
Grade IV: Drive-through sign with 2.7 mm scope

Operative management

Options

Acute scapholunate ligament injury - repair +/- augment

Chronic scapholunate ligament injury / reducible carpus - capsulodesis / tenodesis / RASL / ligament reconstruction

Irreducible carpus / SLAC wrist

- proximal row carpectomy / limited arthrodesis / wrist arthrodesis

www.boneschool.com/SLAC

Acute scapholunate ligament injury

Options

Scapholigament repair +/- capsulodesis

Indications

Acute injury: 1 - 2 months

Amenable to repair: avulsion dorsal SL ligament from scaphoid or lunate

Open technique

SL repair

Dorsal approach

- 3 / 4 interval (3rd and 4th extensor compartments)

- capsulotomy: T shaped or Berger radially based capsule flap

- place K wires into scaphoid and lunate and reduce scapholunate joint

- repair with anchors / drill holes

+/- K wires scaphoid - lunate & scapho-capitate joints

+ / - Augmentation - internal brace / capsulodesis / tenodesis / SL screw

Arthroscopic technique

Arthroscopic SL ligament repair and dorsal capsulodesis PDF

Results

Timing

Chen et al J Hand Surg Glob 2021

- 12 acute SL repair (< 6 weeks) v 12 subacute SL repair (< 12 weeks)

- SL repair with anchors + K wire scapholunate and scaphocapitate joint 6 - 8 weeks

- cast 6 - 8 weeks

- 60 - 75% also underwent capsulodesis

- no difference between 2 groups at 6 year follow up

- 1/12 (8%) acute developed SLAC

- 3/12 (25%) subacute developed SLAC

Arthroscopic repair

Lee et al J Orthop Surg Res 2023

- 19 acute SL injury treated with SL repair and dorsal capsulodesis

- at one year, 95% good or excellent results

- 84% return to previous activities

- failure of repair 5%

Chronic scapholunate ligament injury with reducible carpus and no SLAC

Indications

Chronic injury > 12 weeks

Non reconstructable injury / midsubstance

Reducible carpus - able to reduce scapholunate and scaphocapitate joint

No SLAC / arthritic changes

Options

Tenodesis / capsulodesis	Scapholunate ligament reconstruction / ligamentoplasty
Capsulodesis - dorsal capsulodesis to distal scaphoid Tenodesis - FCR tenodesis distal scaphoid to lunate / distal radius	RASL (Reduction and Association ScaphoLunate) - temporary screw fixation scapholunate joint Scapholunate ligament reconstruction - with FCR / palmaris / bone-tissue-bone - +/- internal brace

Tenodesis / capsulodesis

Scapholunate ligament reconstruction / ligamentoplasty

Capsulodesis

- dorsal capsulodesis to distal scaphoid

Tenodesis

- FCR tenodesis distal scaphoid to lunate / distal radius

RASL (Reduction and Association ScaphoLunate)

- temporary screw fixation scapholunate joint

Scapholunate ligament reconstruction

- with FCR / palmaris / bone-tissue-bone

- +/- internal brace

Results

Capsulodesis v tenodesis

Daly et al Hand 2020

- systematic review of chronic SL injury

- improved outcomes with capsulodesis v tenodesis

Capsulodesis / tenodesis v ligament reconstruction

Wu et al J Wrist Surg 2022

- systematic review of capsulodesis v tenodesis v bone-tissue-bone reconstruction

- best outcome scores with bone-tissue bone

- highest rate of excellent outcomes with bone-tissue-bone 64%

Athlani et al Hand Surg Rehab 2019

- 20 chronic SL injuries treated with 3 ligament tenodesis versus ligament reconstruction

- 2 year followup

- better results with ligament reconstruction

Lami et al J Hand Surg Global 2025

- systematic review of capsulodesis v tendodesis v ligament repair v ligament reconstruction

- repair: SLAC 31%

- ligament reconstruction: SLAC 15%

- capsulodesis: SLAC 11%

- tendodesis: SLAC 14%

Capsulodesis

Blatt capsulodesis

Modified Blatt capsulodesis

Modified Viegas / Berger

Mathoulin capsulodesis

Dorsal approach

- proximally based capsular flap

- reduce SL joint with K wires

- K wire SL joint and SC joint

Attach capsule

- distal pole of scaphoid

- prevents flexion of scaphoid

Dorsal approach

- reduce and K wire SL joint

- identify DIC ligament

Dettach DIC ligament from trapezium

Reattach to distal scaphoid

Dorsal approach

- elevate radial based V shaped flap

- between DIC and DRT ligaments

- tie DIC / DRT ligaments to SL joint

Arthroscopic technique

- reduce SL joint

- tie down dorsal capsule onto SL joint

Vumedi modified Blatt procedure

mod blatt

Techniques

Vumedi modified Blatt procedure

Vumedi arthroscopic Mathoulin

Results

Terras et al Acta Orthop Belg 2025

- systematic review of dorsal capsulodesis for chronic SL injury

- reduced stiffness with modified Viegas / Berger versus Blatt

- best results with all-arthroscopic Mathoulin

Tenodesis

Brunelli - replaces scaphotrapezial ligament, attaches to distal radius

Modified Brunelli - passes under / through radiotriquetral liagment, suture to itself

Three-ligament tenodesis - replaces scapotrapezial / scapholunate / radiotriquetral

Brunelli Wrist Tenodesis	Modified Brunelli	Garcia-Elias Three-ligament tenodesis
Dorsal approach - T capsulotomy or Berger - reduce SL joint with K wires - K wire SL joint and SC joint Second volar approach - harvest half FCR, 8 cm long - leave attached distally Drill hole in scaphoid tuberosity - pass volar to dorsal - insert dorsally to the distal radius	Dorsal approach - T capsulotomy or Berger - reduce SL joint with K wires - K wire SL joint and SC joint Second volar approach - harvest half FCR, 8 cm long - leave attached distally Drill hole in scaphoid tuberosity - aim to exit close to SL joint - pass volar to dorsal Pass under radiotriquetral liagment Suture to carpus / itself	Dorsal approach - T capsulotomy or Berger - reduce SL joint and K wire - K wire SL joint and SC joint Second volar approach - harvest half FCR, 8 cm long - leave attached distally Drill hole in scaphoid tuberosity - aim to exit close to SL joint - pass volar to dorsal Anchor to lunate Pass through radiotriquetral ligament Suture to carpus / itself

Brunelli Wrist Tenodesis

Modified Brunelli

Garcia-Elias Three-ligament tenodesis

Dorsal approach

- T capsulotomy or Berger

- reduce SL joint with K wires

- K wire SL joint and SC joint

Second volar approach

- harvest half FCR, 8 cm long

- leave attached distally

Drill hole in scaphoid tuberosity

- pass volar to dorsal