1) DORSAL APPROACH -
☆ Scaphoid Open Reduction and Internal Fixation from the Dorsal Approach/Mini-Open Approach
•The tourniquet is placed proximally on the arm and draped to allow full motion of the extremity.
INCISION
• A small (≈2-3 cm) longitudinal or transverse incision should be made over the proximal pole at the position of the scapholunate ligament. A miniincision is safer than the purely percutaneous method when approaching from the dorsal wrist .
• Incision is in line between the second and third metacarpal interspaces, and just distal to the dorsal lip of the radius.
• The extensor pollicis longus (EPL) is carefully identified and the second and third dorsal compartment tendons are retracted radially.
•For the mini-open approach, the capsule is opened with a mini inverted-“T” incision.
•Extreme care is taken to avoid disruption of the dorsal fibers of the SLIL(Scapholunate interosseous ligament) when reflecting the capsular flap .
•The distal boundaries of dissection of the scaphoid are determined by the vascular supply along the dorsal ridge. Care is taken not to disrupt the blood vessels entering the waist of the scaphoid .
•Retractors are placed deeper to retract the capsule.
• If the scaphoid is displaced, the hematoma should be evacuated and the scaphoid reduced, possibly with the aid of smooth Kirschnerwire joysticks, if necessary.
ENTRY POINT
• The wrist is flexed and the entrance point on the scaphoid is identified 1 to 2 mm radial to the membranous portion of the scapholunate ligament and in the midportion of the scaphoid in the sagittal plane.
•The guide wire is inserted in the axis of the shaft of the first metacarpal, in radial abduction.
•Image intensification in at least two planes is used to confirm accurate advancement of the guide wire in the scaphoid axis, and perpendicular to the fracture plane.
Do not penetrate the scaphotrapezial joint with the guide wire.
Do not penetrate the scaphotrapezial joint with the guide wire.
• It is important to take several oblique views to ensure that there is no guide wire or screw penetration out of the scaphoid in any view.
• In order to obtain the PA images while keeping the wrist flexed, it is imperative to flex the elbow. A center-center position of the guidewire in all views (PA, lateral, and oblique) should be obtained.
MEASUREMENT
• Once the wire position is determined to be optimal, the wire is advanced to the subchondral bone on the distal end of the scaphoid bone. This distance is then measured. The appropriate screw length is shorter than this distance by at least 4 mm; For an adult man, 20 mm is often an appropriate length.
• If the screw is too long , it can distract the fracture if it hits the unyielding distal subchondral bone or protrude out of the bone distally or proximally or may not cause compression if the thread lies within fracture site.
Drilling and tapping
•Use only the dedicated drill bit. A small power drill with slow rotation is preferable.
Use Ringer lactate solution to cool the drill bit, in order to minimize thermal injury.
•If the drill guide is used, attach a nut to the drill bit in order to limit penetration to the desired length only.
•Check the position of the tip of the drill bit using image intensification.
•Then tap the drill hole manually if not using self-tapping screws.
Use Ringer lactate solution to cool the drill bit, in order to minimize thermal injury.
•If the drill guide is used, attach a nut to the drill bit in order to limit penetration to the desired length only.
•Check the position of the tip of the drill bit using image intensification.
•Then tap the drill hole manually if not using self-tapping screws.
Screw insertion
•After Countersinking(to decrease the hoop stresses on proximal bone which can cause a fracture in the proximal bone ),the proximal end of the screw should be advanced until it is buried beneath the subchondral bone.
• position of the screw is confirmed using image intensification.
Immediate postoperative treatment
Rest the wrist with a well-padded below-elbow splint for 48 hours.
•The wrist is hyperextended and ulnarly deviated over a bump. This moves the trapezium dorsally away from the entrance point on the scaphoid bone.
B, With the wrist in neutral position, the trapezium blocks the scaphoid bone. A, With the wrist in the hyperextended position, the trapezium moves dorsally out of the way for access to the starting point on the scaphoid bone. C, Even with the wrist extended, it is not possible to get down the true axis from the volar approach, because the trapezium is in the way.
•The wrist capsule is entered through a longitudinal incision from the volar lip of the radius to the proximal tubercle of the trapezium.
•The capsule needs to be preserved, as it contains the RSC ligament and will be repaired at the close of the procedure.
•If the trapezium has a particularly palmar location, a rongeur may be needed to remove a small amount of bone to gain access to the entrance point.
•The guidewire is started as dorsally as possible on the scaphoid in the sagittal plane without impinging on the trapezium. On the coronal plane, a good landmark for the starting point is a third of the distance from the radial side of the distal pole of the scaphoid.
•The surgeon should attempt to drop the hand to get as close as possible to the axis of the scaphoid.
•Once the guidewire is placed, multiple minifluoroscopic views are taken , it is imperative to take 45-degree oblique views in supination and pronation to ensure that the wire is within the bone in all planes.
Immediate Post operative treatment-
•Rest the wrist with a well-padded below-elbow splint for 48 hours.
FUNCTIONAL EXERCISES
Protocol as desribed above .
Functional exercises
•Immediately postoperatively - begin active, controlled, digital range-of-motion exercises.
•At 2 weeks Post operatively - Active motion exercises of the wrist begin in compliant patients with stable fixation. In cases of initial fracture displacement, or comminution, the wrist should be immobilized in a palmar splint until at least 6 weeks after operation.
•After bone healing- Load bearing through the wrist must be delayed until there is radiological evidence of bone healing. This may be difficult to assess on conventional radiographs; follow-up CT scans are recommended.
2) PALMAR APPROACH -
Scaphoid Open Reduction and Internal Fixation From the Palmar Approach/ mini open approach-
•In the open volar approach, a hockey-stick incision is made beginning between the flexor carpi radialis (FCR) tendon and the radial artery in the distal forearm and angled across the distal wrist crease toward the base of the thumb.
•The FCR tendon is retracted ulnarly and the radial artery radially.
☆ In the Mini open approach -
•A small longitudinal incision (≈1 cm, or just long enough to accommodate the drill bit/ screw) is made over and just distal to the scaphoid tubercle.
•At 2 weeks Post operatively - Active motion exercises of the wrist begin in compliant patients with stable fixation. In cases of initial fracture displacement, or comminution, the wrist should be immobilized in a palmar splint until at least 6 weeks after operation.
•After bone healing- Load bearing through the wrist must be delayed until there is radiological evidence of bone healing. This may be difficult to assess on conventional radiographs; follow-up CT scans are recommended.
2) PALMAR APPROACH -
Scaphoid Open Reduction and Internal Fixation From the Palmar Approach/ mini open approach-
•In the open volar approach, a hockey-stick incision is made beginning between the flexor carpi radialis (FCR) tendon and the radial artery in the distal forearm and angled across the distal wrist crease toward the base of the thumb.
•The FCR tendon is retracted ulnarly and the radial artery radially.
☆ In the Mini open approach -
•A small longitudinal incision (≈1 cm, or just long enough to accommodate the drill bit/ screw) is made over and just distal to the scaphoid tubercle.
•The wrist is hyperextended and ulnarly deviated over a bump. This moves the trapezium dorsally away from the entrance point on the scaphoid bone.
•The wrist capsule is entered through a longitudinal incision from the volar lip of the radius to the proximal tubercle of the trapezium.
•The capsule needs to be preserved, as it contains the RSC ligament and will be repaired at the close of the procedure.
•If the trapezium has a particularly palmar location, a rongeur may be needed to remove a small amount of bone to gain access to the entrance point.
Fracture displacement forces
In fractures of the waist of the scaphoid, the distal pole tends to rotate into flexion in relation to the proximal pole, the lunate and the triquetrum, which lie in extension. This can create a rotational and angular deformity at the fracture site – the so-called “humpback deformity”.
REDUCTION-
1) manual manipulation - distract, extend and deviate the wrist towards the ulna to expose the fracture line
2) Direct reduction using reduction forceps, k-wire fixation .
ENTRY POINT- •The guidewire is started as dorsally as possible on the scaphoid in the sagittal plane without impinging on the trapezium. On the coronal plane, a good landmark for the starting point is a third of the distance from the radial side of the distal pole of the scaphoid.
•Guide wire entry at the palmar edge of the scaphotrapezial joint .
Insertion of guide wire
•The guide wire track must be angled 45 degrees dorsally, and 45 degrees medially, along the mid-axis of the scaphoid.
The position of the wire should be as perpendicular as possible to the fracture line.
The position of the wire should be as perpendicular as possible to the fracture line.
Measurement of length-
1) using the measuring device
2) using another k wire of same length
Drilling and Tapping-
•Check the position of the tip of the drill bit using image intensification.
•The wire is advanced till the subchondral bone on the proximal side and measured.
The appropriate screw length is shorter than this distance by at least 4 mm.
• usually 20mm length of screw is sufficient in adult.
•The screw should be relatively long but should definitely not be too long.
Fractures with a defect: Add bone graft
•In the case of fracture comminution, particularly with compromise of the palmar cortex, or a defect after removal of loose fragments, autogenous, cancellous bone graft, is necessary.
•Make a 2 cm longitudinal incision proximal to Lister’s tubercle.
•Make a 2 cm longitudinal incision proximal to Lister’s tubercle.
Confirm screw position
•Check the final position of the screw, and the scaphoid stability using image intensification.
Immediate Post operative treatment-
•Rest the wrist with a well-padded below-elbow splint for 48 hours.
FUNCTIONAL EXERCISES
Protocol as desribed above .
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