Prosthesis or trapezectomy, Why to choose ?
Semi-constrained prosthesis with total trapezectomy Modular prosthesis with interchangeable heads and stems HAP coating for better fixation of the prosthesis in the metacarpus Head surmounted with MED 4765 silicone elastomer
Surgical Technique Posterior external approach
1
The incision is rectilinear from the radial styloid until the mark found in the middle of the 1st metacarpal bone. - Careful subcutaneous dissection by preserving the sensitive branches of the radial nerve. - Location of the extensor pollicis brevis and abductor pollicis longus tendons. - The capsule approach is made between these 2 tendons. - At anatomical snuffbox level, location and dissection of the radial artery and veins, which will be lifted from the joint capsule by the standard Senn-Millertype retractor. - Common hemostasis of the first metacarpal bone and the arterial branch progressing along the trapezium.
T shaped articular approach
2
A T-shaped articular approach, whereby the horizontal branch is located 2-3mm below the scapho-trapezian joint, and the vertical branch is in the trapezo-metacarpal axis, is favoured. - Dorsal periosteum incision on the proximal middle of the 1st metacarpal bone going as far as the dorsal side of the trapezium. - Internal and external detachment of the periosteum and crowning of the base of the 1st metacarpal bone. External, upper and internal capsular separation of the trapezium until the crowning of the proximal scaphotrapezian spaces and the internal trapezo-trapezodian.
Cut the metacarpal with an oscillating saw.
strictly
perpendicular
to
the
longitudinal
metacarpal
axis
3
The 1st metacarpal bone is then stabilized using forceps and the cutting of the metacarpal base is carried out using the oscillating saw; this cut is generally from 1 to 3mm deep according to the shape of the base and its wear.
4
Total Trapezectomy
A full trapezectomy is then : -Or Carried out through the outright excision of the bone, using the gimlet A-VRI0045 (beforehand, prepared the bone with a square point or with a 2.5-2.7 mm wrench) - Or carried out through fragmentation, taking care to preserve the capsular flaps. The Flexor Carpi Radialis tendon, on the lower side, must be watched out for and treated gently. The capsular dorsal trapezoidal release is then completed and cut again with the oscillating saw, in accordance with a purely vertical axis, the part of the trapezoid covering the distal pole of the scaphoid. The so-called trapezoid “cone�, with a distal point, is therefore removed Always pay attention not to damage the scaphoid’s cartilaginous distal pole when operating the oscillating saw.
Boring the first metacarpal
5
The medullary canal of the first metacarpal bone is prepared, initially using the square point for centring and then the appropriate drill. It is advisable to delicately shift the centring to the bottom because the anterior curve of the 1st metacarpal bone always makes the mill pull up a little. Always preserve the maximum amount of spongy bone and dorsal cortical substance on the 1st metacarpal bone, where the bone is most fragile. Progressive mechanised milling (low-speed motor) with three possible depths: 3 gauges (always start with size 16, then 18 and 20 if necessary) in order to accurately judge the depth of milling.
The selected stem is fitted in the medullary canal using the A-IMP-6180 impactor.
It is advised, not to screw strongly the stem on the impactor, to avoid removal difficulties
To determine which head to use (straight or tilted), the thumb is placed in intermediate Abduction-Antepulsion: - If the metacarpal bone axis is centered in relation to the scaphoid, a right angle head must be used. - If the metacarpal bone axis is decentred or unbalanced in relation to the scaphoid, a tilted head must be used. These trial parts must lead to good joint congruence, good thumb column length, and the absence of internal cam effect must be verified. Use the head extractor A-EXT-0001 to remove the head trial implant.
Fitting the final prosthesis
6
The metacarpal bone stem already in place, the head is inserted into the stem using the head impactor (A-IMP-0001). The stem and the head must be well interlocked and interdependent of each other. A FIRM IMPACTION is necessary to well lock the head into the stem.
7
Capsular suture
It is preferable to first of all pass the threads through the capsular scaphoid flap (with 2 or 3 spare threads on the side) and then to put the 2 internal and external capsular flaps back superpositioning each other. These 2 flaps must be firmly sutured with the proximal capsular flap; this conditions the future stability of the prosthesis. The dorsal periosteum of the 1st metacarpal bone is also closed up. The cutaneous closing is generally carried out by a subcuticular suture without the need for subcutaneous suture.
Postoperative
8
The bandage is applied with the thumb in Antepulsion Abduction with the first commissure gap. It is recommended that an orthesis be worn post-surgery in this same position in order to aid capsular healing and the future stability of the prosthesis.
Peri-Trapezian arthrosis Dell stage N째 III
Arthrosis Dell stage N째 III
Postoperative radiography Oxalys in palmar eccentricity
Postoperative Radiography Centred Oxalys
Oxalys Semi-constrained prosthesis with total trapezectomy Modular prosthesis with interchangeable heads and stems
Head either straight or tilted at 15째 for better alignment with the scaphoid
Possibility for inserting a suture to give the stem a primary stability in the metacarpal
HAP coating for better fixation of the prosthesis in the metacarpus
Head surmounted with MED 4765 silicone elastomer
Possibility for adjusting the orientation of the tilted head
Indications Degenerative centred trapezometacarpal osteoarthritis or moderately throwed off centre Ankylosed joints, or those with limited range of motion which have not responded to conservative treatment
Contraindications Trapezometacarpal osteoarthrosis with metacarpophalangeal hyperextension superior to 50% no corrected A patient with skin, bone, circulatory and/or neurological defiency Non-functioning and irreparable musculotendinous system
Nofunctional joints due to inadequate bony alignment and joint space which cannot be restored by soft tissue reconstruction alone
active sepsis
Inadequate bone stock
Destroyed articular surfaces
Rhizarthrosis resistant at the medical treatment
Arthrosis throwed off centre with subluxation of the metacarpal base superior to 50%
Rheumatoid arthrisis Allergy in titanium
Implants Straight head
Color code
Straight head references
Désignation
OXA-TDT1
Straight head size 1
OXA-TDT2
Straight head size 2
OXA-TDT3
Straight head size 3
Tilted head Tilted head references
Désignation
OXA-TIT1
Tilted head size 1
OXA-TIT2
Tilted head size 2
OXA-TIT3
Tilted head size 3
Tapered Stem Tapered stem references
Désignation
16
OXA-QCT1
Tapered stem size 1
18
OXA-QCT2
Tapered stem size 2
20
OXA-QCT3
Tapered stem size 3
Ancillaries Article code A-EXT-0001 A-IMP-0001 A-IMP-6180 A-VRI-0045 A-FRA-0002 A-FRA-0003 A-FRA-0004 A-FRA-0005 OXA-FA-TDT1 OXA-FA-TDT2 OXA-FA-TDT3 OXA-FA-TIT1 OXA-FA-TIT2 OXA-FA-TIT3
Description Head extractor Head impactor Stem impactor/extractor Gimlet Ø 4.5 mm Straight-cut drill Drill gauge size 1 Drill gauge size 2 Drill gauge size 3 Trial implant straight head size 1 Trial implant straight head size 2 Trial implant straight head size 3 Trial implant tilted head size 1 Trial implant tilted head size 2 Trial implant tilted head size 3
1 1 1 1 1 1 1 1 1 1 1 1 1 1
Presentation box Boxalys
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