Keywords
distal radius fracture - treatment - fracture fixation - volar plate - dorsal approach
Introduction
Today, intra-articular distal radius categorized as types B and C according to the
new AO classification updated in 2018[1] are mostly treated through open reduction and internal fixation with a volar plate
if surgical stabilization is required. This procedure results in reduced surgical
time and improved functional outcomes, with a similar number of dorsal plate-related
complications reported by recent series.[2]
Some patterns of intra-articular distal radius fractures require a dorsal support,
but the literature regarding the recommended treatment and most optimal fixation method
is controversial. In fractures with dorsal articular fragments or great dorsal comminution,
volar plates do not provide adequate support; in addition, since volar screws usually
do not give sufficient stability to these fragments, there is a risk of loss of fracture
reduction.[3]
Despite the emergence of new surgical techniques with low-profile dorsal locking plates
to treat these fractures, many published series regarding such devices report some
postoperative complications, including implant-related discomfort (often requiring
plate removal after fracture consolidation), extensor tenosynovitis, second, third
and fourth extensor compartment tendons rupture, flexural deficit of the wrist compared
to the mobility provided by volar plates, stiffness, arthrofibrosis, neuropathy of
the sensory branch of the radial nerve, reflex sympathetic dystrophy and carpal tunnel
syndrome.[4]
[5]
[6]
This paper aims to describe the dorsal support technique using double washer screws
fixed to a volar plate as an alternative to dorsal plate in the treatment of distal
radius fracture with comminution and dorsal fragment formation due to lunate fossa
depression, which results from load transmission through the lunate bone (die punch
fracture), and to describe the outcomes from our case series.
Indications
Based on the AO classification for distal radius fractures updated in 2018 by Kellam
and Meinberg,[1] we believe that fixation with a dorsal support screw and a double washer screw attached
to a volar plate can be used in partial articular Barton fractures, dorsal articular
rim fractures (2R3B2.2, 2R3B2.3), other fracture patterns with simple or multifragmented
complete joint involvement and simple metaphyseal involvement with die punch (2R3C1,
2R3C3.1).
According to this AO classification from 2018,[1] we believe that complete joint fractures with a large metaphyseal or diaphyseal
component that would require implants with greater support and fixation points (2R3C2,
2R3C3.2 y 2R3C3.3) can be treated with a dorsal support, double washer screw supplemented
with a longer volar plate or a low-profile dorsal plate.
Surgical Anatomy
At the wrist, 80% of the loads are transferred by the radiocarpal joint, whereas the
remaining 20% are transferred through the carpal ulna joint. Considering the three-column
principle at the wrist joint, the radial column articulates with the scaphoid bone,
while the intermediate column articulates with the lunate bone through its facet or
fossa, a structure damaged by impaction and displacement in die punch fractures.
Surgical Technique
The patient is placed in supine recumbency on an orthopedic table and an auxiliary
hand table. The arm is attached to the auxiliary table and a fishing rod is attached
to the opposite side of the lesion to facilitate positioning during arthroscopy. All
patients were submitted to regional anesthesia and antibiotic prophylaxis with intravenous
administration of 2 g of cefazolin. An ischemia cuff is placed at the arm at 100 mm
Hg above the systolic pressure. The flexor carpi radialis sheath is approached, followed
by the systematic release of the brachioradialis muscle attachment; the wrist is accessed
through a small dorsal approach at the third extensor compartment, longitudinally
opening the extensor retinaculum and lifting the fourth compartment subperiostatically
towards the ulna without opening it, thus avoiding possible adhesions and dorsal fragments
release. Arthroscopic control is performed mainly through 3-4 and 6R radiocarpal portals,
as well as the radial and ulnar midcarpal portals.[7]
The fracture is reduced, and a provisional fixation is performed using isolated Kirschner
wires and/or a plate. If the radioscopic control is adequate, arthroscopy using 3-4
and 6 R portals reveals the correct reduction of the articular fragments, as well
as the integrity of the triangular fibrocartilage complex and distal radioulnar joint.
Intrinsic carpal ligament structures are systematically reviewed using midcarpal portals.
After assuring the provisional fixation of the fracture, the final fixation is carried
out using the Acu-loc2 7 × 4-hole low-profile locking plate (Acumed, Hillsboro, Oregon,
USA) with proximal cortical fixation or 3.5-mm screws and distal, 2.3-mm locking screws
with optional placement in a nominal angle predefined by a distal locking guide or
in a variable angle using a 0-15° screw targeting device. The first 3.5-mm bicortical
screw is placed in the proximal central hole and the 2.3-mm distal locking screws
are placed over the targeting guide in the distal holes, except for the hole in which
the dorsal screw will be positioned later. Subsequently, the remaining proximal screws
are placed, and the correct joint reduction is rechecked by arthroscopy.
The dorsal ulnar fragment is accessed through a dorsal approach. Next, a 2.3-mm compression
cap and a 0.3-mm guidewire (which was recovered through the dorsal area after fragment
reduction) are inserted at the free hole in the distal row of the plate (the more
ulnar hole is more commonly used, although this choice depends on the location of
the main dorsal fragment). A 2.3-mm dorsal cannulated screw, with two 7 and 13-mm
washers to increase the holding surface, is threaded into the volar compression sleeve
using the guidewire. The appropriate compression must be applied to avoid collapse,
increased fragment comminution or screw head protrusion, which would subsequently
affect the extensor apparatus of the wrist ([Figure 1]).
Fig. 1 Intraoperative images showing the placement of double dorsal, 7 and 13-mm washers
using a guidewire (1A). Placement of the 2.3-mm back support screw threaded to the volar compression sleeve
over the double washer and guidewire (1B, 1C). Arthroscopic images after screw placement (1D, 1E).
In dorsal closure, the extensor pollicis longus tendon is left outside the reflection
pulley of the Lister tuber, at the subcutaneous level. Since the fourth compartment
has been raised subperiostatically but not opened, extensor retinaculum closure does
not require a flap, avoiding the engagement of the fixation material to the extensor
apparatus described in some case series.[8] The skin is closed with sutures or staples.
Postoperative Period
The patient is discharged before 24 hours post-surgery if no complications are reported.
Immobilization with a metacarpal-antebrachial dorsal plastered splint in a functional
position is performed at the operating room. The splint is kept for 3 weeks. Metacarpophalangeal
joints remain free and active finger mobilization is recommended during this period.
Skin sutures are maintained for 2 to 3 weeks. After splint removal, active wrist mobilization
exercises and contrast baths are indicated, with no weight bearing or demanding manual
activity up to 12 weeks. Radiological follow-up is performed at 4, 8 and 12 weeks.
Complications
The cases reported here presented no short- or medium-term complications; however,
potential complications include those related to the treatment of distal radial articular
fractures with locking plates, such as flexor pollicis longus tenosynovitis, flexor
or extensor tendons rupture, surgical wound infection, median nerve or posterior interosseous
nerve neuropathy, implant failure or osteosynthesis material loosening, delayed or
absent consolidation, wrist stiffness and radiocarpal degenerative disease.
Clinical Cases
We present three female patients aged 52, 80 and 71 who came to the emergency room
with pain and wrist functional disability after suffering a low-energy trauma. At
the physical examination, they presented edema, deformity and pain on wrist mobilization
in flexion-extension and radial and ulnar deviation. They did not show signs of distal
neurovascular deficit, with good capillary filling and good finger coloration. One
of the cases presented a 2 cm diameter wound at the ulnar dorsal level compatible
with an open fracture, type 2 according to the Gustilo classification.[9] Anteroposterior and lateral radiographies of the wrist showed intra-articular distal
radius fractures with radial styloid process fragments, dorsal and volar comminution
and dorsal fragments with articular sinking consistent with die punch.
All patients were submitted to a closed reduction after intrafocal infiltration with
10 mL of 2% mepivacaine; 2 g of cefazolin were intravenously administered in the case
of open fracture. Next, patients were immobilized with an antebrachial cast that was
subsequently opened in its entire length for radiological follow-up assessments ([Figure 2]). The three cases were evaluated by physicians from the Upper Limb Unit from our
Department, and all were submitted to surgical treatment with open reduction and plate
osteosynthesis. One of the cases required an additional plate due to radial styloid
process fragmentation through the same approach used for volar plate fixation. Another
case required radial fixation using a volar plate with metaphyseal prolongation and
ulnar fixation by a distal ulnar plate in an additional dorsal ulnar approach due
to metaphyseal comminution and fracture instability ([Figure 3]). None of these cases presented triangular fibrocartilage complex or intrinsic carpal
ligaments lesions.
Fig. 2 Preoperative radiographs of a 52-year-old patient with an articular distal radius
fracture with radial and ulnar styloid fragments and one dorsal die punch fragment
(2A, 2B). Post-immobilization, preoperative radiographs of an 80-year-old female patient
with an articular distal radius fracture with a displaced volar fragment and large
dorsal comminution (2C, 2D). Post-immobilization, preoperative radiographs of a 71-year-old patient with an articular
distal radial and ulnar fracture with large dorsal, metaphyseal, and distal ulnar
comminution (2E, 2F).
Fig. 3 Postoperative radiographs from case 1 after 4 weeks. Dorsal die punch fragment reduction
with a double washer, dorsal support screw (3A, 3B). Postoperative radiographs from case 2 after 12 weeks. Reduction with a volar plate
and a radial styloid plate (3C, 3D). Postoperative radiographs from case 3 after 12 weeks. Reduction with a volar plate,
metaphyseal extension and an ulnar plate (3E, 3F).
At the outpatient postoperative follow-up, the range of mobility, Disability of the
Arm Shoulder and Hand (DASH) questionnaire score[10] and average Visual Analog Scale (VAS) score[11] were recorded; in addition, complete consolidation fracture was verified radiologically.
Twelve weeks after surgery, outcomes included the following:
Case 1: 50° dorsal flexion, 40° volar flexion, complete supination, -20° pronation.
Mean DASH questionnaire score, 40 points; mean VAS scale score, 4 points.
Case 2: 45° dorsal flexion, 40° volar flexion, complete supination, complete pronation.
Mean DASH questionnaire score, 35 points; mean VAS scale score, 3 points.
Case 3: 40° dorsal flexion, 35° volar flexion, -10° supination, -20° pronation. Mean
DASH questionnaire score, 50 points; mean VAS scale score, 4 points.
Discussion
To reduce the rate of complications associated with dorsal plates in distal radius
fractures, such as tenosynovitis, extensor tendons rupture or implant-related discomfort,
some series describe other techniques and alternative surgical maneuvers for dorsal
fragments reduction, such as provisional partial volar radial decortication through
the plate with subsequent lifting and dorsal fragment reduction with an elevator or
periosteotome inserted through the decortication area[12] or the use of an anteroposterior compression clamp to help fracture reduction in
the sagittal plane, allowing sufficient dorsal distal fragments displacement to adequately
fix them with Kirschner wires and volar screws.[13] In our three cases, using the dorsal support technique and volar plate fixation,
none of the previously described complications associated with dorsal fixation systems
were recorded.
Recent series limited the number of postoperative complications by using innovative
dorsal plates and other fixation methods.[14] Some publications compare the radiological and functional outcomes from dorsal plates
to those obtained with volar plates.[3]
[4]
[5] Other studies report that routine removal of dorsal fixation material is not required
unless there are signs such as dorsal wrist pain that does not improve during the
postoperative follow-up period, which is the main indicator of implant-related soft
tissue problems.[15]
Dorsal die punch fixation with a volar plate and a dorsal, double washer screw fixed
to the plate may be an alternative to other fixation techniques to reduce articular
fragments and treat the associated comminution. This dorsal screw allows compression
of the main dorsal joint fragment, but it can increase the comminution, increasing
the risk of fracture collapse in cases of severe osteoporosis. The double 7- and 13-mm
washers add a suitable back support surface to avoid such complications in small fragments.
This technique also allows other surgical maneuvers, such as the use of autologous
bone graft in cases of bone loss, arthroscopic-assisted joint fragment reduction,
or the placement of an osteosynthesis plate for the radial styloid process or distal
ulna as an additional fixation method.
In summary, we consider that osteosynthesis using a volar plate and a dorsal support
screw with a double washer through the plate can lead to similar functional outcomes
and reduce the rate of complications associated with the treatment of intra-articular
distal radius fractures associated with dorsal die punch and commutation with dorsal
plates; in addition, this technique provides greater stability compared to volar plates
for dorsal fragments fixation. However, further studies with a greater number of cases
and longer follow-up periods are required to obtain more solid conclusions on the
effectiveness of this fixation method.
