- Discussion:
- most common and most significant ligament injury of wrist; (
carpal instability);
- risk factors: ulna minus configuation, slope of radial articular surface, and lunotriquetral coalition;
-
spectrum of injury: (increasing severity)
- dynamic scapholunate instability
- no radiographic evidence of malalignment is present (ie dynamic deformity);
- diagnosis is established by dorsal S-L tenderness and positive shift test;
- rotatory subluxation of scaphoid:
- scapholunate dissociation (SLD):
- scapholunate ligament tear may lead to rotational dislocation of scaphoid allowing proximal pole to displace posteriorly
& distal pole to displace anteriorly;
- scaphoid inherently tends to palmar flex because of its oblique position and the loading applied thru (STT) joint;
- because scaphoid lacks proximal of
ligament, it will rotate around radiocaptitate ligament leading to dorsal rotary subluxation of the proximal pole;
-
dorsal intercalated segment instability: (DISI)
-
scapholunate advanced collapse:
-
mechanism of injury:
- mechanism is similar is similar to that of
scaphoid frx w/ stress loading of extended carpus, except it is usually in ulnar rather than radial deviation;
- w/ a severe hyperextension injury of the wrist, there is tear of scapholunate interosseous ligament;
- further loading causes tear of (in succession);
- radiocapitate ligaments;
- radiotriquetral ligaments;
- dorsal radiocarpal ligaments;
- lunate follows triquetrium into extension, &
DISI deformity results;
-
anatomy and ligamentous contraints: (
ligaments of the wrist)
-
associated injuries:
- simultaneous
radial styloid frx is relatively common w/ carpal dislocation;
- always consider
non-displaced scaphoid frx;
-
diff dx:
- scaphoid impaction syndrome (SIS);
-
occult ganglion cyst;
- posterior interosseous nerve neuroma;
-
ulnar translocation:
- physiologic scapholunate separation such as lunotriquetral coalition (compare to other hand);
-
perilunate dislocation (which has be reduced and splinted)
- references:
-
Is this scapholunate joint and its ligament abnormal .
-
Wide scapholunate joint space in lunotriquetral coalition: a normal variant.
-
Coincident rupture of the scapholunate and lunotriquetral ligaments without perilunate dislocation: pathomechanics and management.
- Radiographic Findings: in Scapholunate Dislocation:
-
Traction radiography for the diagnosis of scapholunate ligament tears.
- Exam for Scapholunate Instability:
- Non Operative Treatment:
- non operative treatment can only be recommended for dynamic scapholunate instability;
- suggested measures include: activity modification, NSAIDS, and wrist splinting;
- references:
-
Chronic asymptomatic contralateral wrist scapholunate dissociation.
-
Obvious radiographic scapholunate dissociation: X-ray the other wrist.
- Treatment Options for Acute Tears:
-
manipulation & closed pinning:
- may correct a fresh scapholunate dissociation;
- flex & ulnar deviate the wrist to produce lunate reduction & flexion;
- consider initial retrograde insertion of K wire through the scaphoid and out the radial side of the wrist, pulling the K wire out radially, and then
advancing the K wire into the ulna;
- be aware that K wire insertion may displace lunate;
- K wire should be inserted into distal cortex of lunate, but midcarpal joint should be left free to absorb small movements;
- scaphoid should be pinned similarly if not perfectly reduced to lunate;
- reduction of scaphoid is achieved w/ thumb pressure dorsally over proximal pole;
- avoid distraction using slow insertion under flouroscopy;
-
acute ligament repiar w/ dorsal capsulodesis
- dynamic reconstruction:
-
Dynamic Repair of Scapholunate Dissociation With Dorsal Extensor Carpi Radialis Longus Tenodesis
-
Brunelli Tenodesis :
Distal Tunnel Placement Improves Scaphoid Flexion With the Brunelli Tenodesis Procedure for Scapholunate Dissociation
- Treatment Options for Chronic Tears:
-
dorsal intercarpal ligament capsulodesis:
- this technique does not tether the scaphoid to the distal radius (as does the blatt capsulodesis), the technique may permit
good closure of the scapholunate gap without restricting wrist motion;
- in the study by Slater et al 1999, the dorsal intercarpal ligament capsulodesis reduced SLD gap formation down to 1 mm vs 3.7 mm using
the blatt dorsal capsulodesis technique;
- technique:
- a 5 mm wide flap of dorsal intercarpal ligament (triquetral-trapezoidal) is elevated off of the trapezoid (left attached to the triquetrum);
- scaphoid is taken out of its flexed position (surgeon's finger on the scaphoid tubercle) and the scapholunate gap is reduced;
- flap is then rotated down, stretched as tightly as possible, and is then attached to the distal pole of the scaphoid (about 3-4 mm proximal to the STT joint);
- references:
-
Dorsal intercarpal ligament capsulodesis for scapholunate dissociation: biochemical analysis in a cadaver model.
-
Dorsal intercarpal ligament capsulodesis for chronic, static scapholunate dissociation: Clinical results
-
blatt dorsal capsulodesis:
- involves creation of a flap of wrist capsule (left attached to the radius) which is inserted onto the dorsal pole of the scaphoid;
- the fact that there remains a tether to the distal radius may infact be a disadvantage of this procedure;
- can be used instead of, or in addition to, the repair of the ligament, and can be performed for chronic dynamic instability as well as for chronic SLD;
- capsulodesis keeps scaphoid from subluxating in palmar direction and corrects flexed posture of scaphoid;
- disadvantages: fails to correct the diastasis and significantly decreases wrist ROM;
- technique:
- dorsal capsular flap is left attached to radius proximally & is then subsequently inserted in distal part of the scaphoid to tether distal pole dorsally;
- length of the dorsal capsular flap from the origin at the distal radius to the STT joint;
- references:
- Blatt, G. Hand Clinics. Vol 3. 1987. p 81-102.
- Dynamic scapholunate instability: results of operative treatment with dorsal capsulodesis.
BI. Wintman et al.
-
STT fusion;
-
scapholunate fusion:
- mentioned only to be condemned;
- expect non union rates over 90%;
- references:
-
Scaphocapitolunate arthrodesis.
-
Scaphocapitolunate arthrodesis.
-
Scaphoid-trapezium-trapezoid fusion in the treatment of chronic scapholunate instability.
-
Scaphocapitolunate arthrodesis.
-
Treatment of scapholunate dissociation. Rotatory subluxation of the scaphoid.
-
A comparison of scaphoid-trapezium-trapezoid fusion and four-bone tendon weave for scapholunate dissociation.
-
Attempted scapholunate arthrodesis for chronic scapholunate dissociation.
- Treatment of scapholunate dissociation: preferred treatment--STT fusion vs other methods.
Watson HK. Belniak R. Garcia-Elias M. Orthopedics. 14(3):365-8; discussion 368-70, 1991 Mar.
-
Four-bone ligament reconstruction for treatment of chronic complete scapholunate separation.
-
Long-term follow-up of scaphoid-trapezium-trapezoid arthrodesis.
-
Evaluation of the biomechanical efficacy of limited intercarpal fusions
for the treatment of scapho-lunate dissociation.
-
Treatment of scapholunate dissociation by ligamentous repair and capsulodesis.
- Scapholunate Advanced Collapse (SLAC):
-
Proximal Row Carpectomy:
-
4 Corner Fusion:
-
Wrist Fusion:
- reference:
-
Fascial implant arthroplasty for treatment of radioscaphoid degenerative disease.
-
On resection of the proximal carpal row.
-
Proximal row fusion as a solution for radiocarpal arthritis.
-
Scaphoid excision and capitolunate arthrodesis for radioscaphoid arthritis.
-
Treatment of scapholunate dissociation by ligamentous repair and capsulodesis.
-
Radio-scapho-lunate partial wrist arthrodesis following comminuted
fractures of the distal radius.
Symposium--Progress in Sports Medicine: Athletic Injuries of the *Wrist.*
Dorsal intercarpal ligament capsulodesis for scapholunate dissociation: biochemical analysis in a cadaver model.
RR Slater MD et al. Journal of Hand Surgery. Vol 24-A. No 2. March 1999. p 232.
