DRUJ AND TFCC INJURIES Flashcards
4 main conditions associated with DRUJ
- DRUJ instability = acute vs. chronic
- TFCC tears
- Ulnocarpal abutment syndrome
- DRUJ arthritis
Movement at the DRUJ
ROC of sigmoid notch 15mm
ROC of ulnar head 10mm
Results in rotation and translation
Pronation associated with dorsal translation
Supination associated with volar translation
Shape of DRUJ articular surfaces in coronal plane
- Parallel = most common
- Oblique
- Reverse oblique
Shape of DRUJ articular surfaces in axial plane
- Flat = most common
- flat DRUJ = higher risk of instability - C-type
- S-type
- Ski slope
Fovea and ulnar styloid attachments
Fovea
- at base of ulnar styloid
- devoid of articular cartilage
- primary attachment for radioulnar ligaments
- secondary attachment for ulnocarpal ligaments
Ulnar styloid
- secondary attachment for radioulnar ligaments
Stabilisers of the DRUJ
Static vs. dynamic or bony vs. soft-tissue
Static stabilisers:
1. Articular congruity = minor factor
- max articular contact in neutral rotation = 60%
- min articular contact in terminal pronation/ supination = 10%
2. Capsule
3. Ligaments = TFCC
4. Interosseous membrane
Dynamic stabilisers:
1. ECU
2. PQ
Structures that form TFCC
- Superficial and deep dorsal radioulnar ligaments
- main dorsal stabilisers
- taut in pronation - Superficial and deep volar radioulnar ligaments
- main volar stabilisers
- taut in supination - Central articular disc
- central 2/3 avascular with no healing potential - Meniscal homolog
- Ulnar collateral ligament
- Origin of ulnotriquetral and ulnolunate ligaments
- ECU subsheath
Blood supply to TFCC
- Dorsal and volar branches of anterior interosseous artery
- Radiocarpal branches of ulnar artery
- ulnar aspect and peripheral 1/3 are vascular
- radial aspect and central 2/3 are avascular
Origin and insertion of radioulnar ligaments
Origin = sigmoid notch of radius
Insertion
- deep fibres = fovea
- superficial fibres = ulnar styloid
Positive fovea sign
- Tenderness in foveal soft spot = depression bounded by FCU tendon, ECU tendon, ulnar styloid and triquetrum
- 90% sensitivity and specificity for TFCC or ulnocarpal ligament tears
Ulnocarpal stress test
- Wrist in pronation and ulnar deviation
- Axial load with flexion and extension of wrist
- Positive test is reproduction of pain
Classification of TFCC injuries
Palmer classification = based on mechanism of injury and location of tear
Class 1 = traumatic TFCC tears
Class 2 = degenerative TFCC tears
- central tears are most common
General principles for management of traumatic and degenerative TFCC tears
Traumatic tears: 1. Immobilisation = supination cast 4/52 + SA cast 2/52 2. Repair 3. Reconstruction Degenerative tears: 1. Immobilisation 2. Debridement 3. Address underlying cause
3 indications for surgical management of traumatic TFCC tears
- Failure of nonoperative measures = persistent pain
- Joint instability
- Associated fractures = anatomical reduction of fractures often restores stability
Plain radiographs to assess DRUJ
90-90 position with forearm in neutral rotation
- On PA view, neutral position indicated by ECU groove lying radial to ulnar styloid
- On lateral view, neutral position indicated by pisiform lying midway between scaphoid tubercle and volar capitate
MRI for assessment of TFCC injuries
- MRI is best imaging modality for TFCC tears
- T2 weighted images best = look for high signal
- sensitivity = 80-100%
Arthroscopic assessment of TFCC instability
Trampoline test = hypermobility indicates TFCC instability
Radiographic assessment of DRUJ instability
- Axial CT is best
- Multiple methods
- Congruency method = congruency of arcs formed by sigmoid notch and ulnar head
Differentials for ulnar-sided wrist pain
Bony vs. soft-tissue Bony causes: 1. Distal radius fracture 2. Distal ulna fracture 3. DRUJ injury 4. Essex-Lopresti injury 5. Triquetral/ pisiform/ hamate fracture 6. Kienbock's Disease 7. Ulnocarpal abutment 8. Ulnocarpal arthritis 9. LT arthritis Soft-tissue causes: 1. FCU tendonitis 2. ECU tendonitis 3. TFCC injury 4. LT ligament injury 5. Ulnar nerve neuroma
Principles of surgical management of Galeazzi injuries
Anatomical reduction and fixation of radius fracture
Screen DRUJ stability:
1. Stable = early ROM
2. Unstable but reducible
- immobilise in reduced position
dorsal dislocations reduce and stable in supination
volar dislocations reduce and stable in pronation
- K-wires/ TFCC repair/ ulnar styloid fixation
3. Irreducible
- open reduction via dorsal L-shaped incision
- remove blocks to reduction = ECU tendon
- K-wires/ TFCC repair/ ulnar styloid fixation
Indications for TFCC reconstruction
- Chronic non-repairable TFCC tears causing joint instability
- No arthritis
Aetiology of DRUJ arthritis
4IT CASH or traumatic vs. atraumatic
- Idiopathic/ primary OA
- Inflammatory = RA
- Instability
- Traumatic
5 main surgical options for DRUJ arthritis
- Darrach procedure
- Sauve-Kapandji procedure
- Wafer procedure
- Ulna hemiresection arthroplasty
- Ulna head replacement
Darrach procedure: Advantages Disadvantages Indications Contraindications Technique
- Advantages
- technically easier
- faster recovery = shorter immobilisation - Disadvantages = 4 main complications are
- stump instability
- radioulnar convergence
- ulnocarpal translocation
- weakness - Indications
- elderly low-demand patients
- ulnocarpal and DRUJ arthritis
- RA patients without ulnocarpal translocation - Contraindications = high-demand patients
- Technique
- Subperiosteal exposure of the ulnar head
- Ulnar osteotomy proximal to sigmoid notch (max 2cm)
- Preservation of ulnar styloid and its attachments
- Bevel end of stump to smooth bullet shape to prevent tendon attrition
- Interposition of PQ between radius and stump to prevent radioulnar convergence
- Volar capsulodesis to dorsal ulna to stabilise stump
Sauve-Kapandji procedure: Advantages Disadvantages Indications Contraindications Technique
- Advantages
- less stump instability
- no radioulnar convergence
- no ulnocarpal translocation
- less weakness - Disadvantages
- technically harder
- slower recovery = 6wks immobilisation
- complications = stump instability, nonunion - Indications
- active high-demand patients
- ulnocarpal and DRUJ arthritis
- RA patients with ulnocarpal translocation - Contraindications = risk factors for nonunion
- Technique
- Dorsal approach through 5th extensor compartment
- L-shaped capsulotomy to expose DRUJ
- Pass 2x K-wires into ulnar head
- Prepare DRUJ surfaces
- Centre ulnar head in sigmoid notch
- Advance wires across sigmoid notch into radius
- Pass 2x cannulated screws over wires
- Resect 10mm of ulna proximal to DRUJ
