monteggia technique

8/8/2019 Monteggia Technique

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22 A1.3(Monteggia fractures)

Indications

y Monteggia fractures (adults)

Contraindications

y Soft-tissue conditions

y Noncompliant patient (the radial head needs to be reduced in anycase)

Advantages

y S pontaneous and lasting reduction of radial headRing D, Jupiter JB, Simpson NS (1998) Monteggia fractures inadults. J Bone Joint Surg Am; 80 (12):1733-44.

y Less risk of secondary radial head dislocation

NoteThe restoration of ulnar length is the goal of any treatment of this fracture,allowing spontaneous reduction of radial head. Open reduction of the radial

head and repair of the annular l igament are seldom required.

Reduction and retention of the radial head is mandatory with any treatment.

CREF

Indications

y Open fracture of a higher degree (eg, Gustilo 2 & 3)

y Soft-tissue condition (eg, burn)Ostermann PA, Henry SL, Seligson D (1987) Treatment of ulna

fracture with external fixation a useful alternative Unfallchirurg;

90 (3):122-127. German.

Advantages

y Rapid procedure

y Inexpensive

y Modest risk of infection

Disadvantages

y Pin-track infection

y Less comfortable

y Does mostly not qualify as definitive treatment: Relative stabilityand risk of prolonged healing with need for conversion to OR IF

ORIF

Indications

y Standard procedure for Monteggia fractures

y Secondary procedure after CREF

Contraindications

y Critical soft-tissue condition

Advantages

y Anatomical reduction and early functional treatment

y Patient¶s comfort

Note

For Monteggia fractures we favor OR IF providing absolute stability andadequate radial head reduction.For the management of radial head dislocation and / or fracture we refer to the

Bado classification. In almost all cases the radial head reduces spontaneouslywith the fixation of the ulna and doesn¶t need further surgical treatment.R ing D, Jupiter JB, Simpson NS (1998) Monteggia fractures in adults. J

Bone Joint Surg Am; 80 (12):1733-44.

In the event of inadequate reduction and / or persistent instability of radialhead open revision is preferred. In the event of an additional radial head

fracture treatment depends on fracture type (Mason classification). Radialhead fractures are treated according to the guidelines for isolated radial headfractures.Prognosis is worst with comminuted radial head fracture.

Plates and Screws

One-third tubular plates are adequate only for very distal fractures(Dimension: 3.5mm).

DCP Advantage

y Inexpensive Disadvantage

y Vascular / periosteal compromise

LC-DCP

Advantage

y Less vascular / periosteal compromise and improved axialcompression compared to DCP

LCP Advantage

y Good anchorage in osteoporotic bone with less screw loosening

Disadvantage

y New implant with no long-term follow-up yet

y Bulky implant in small forearmsNoteCerclage wire and screws alone are not adequate for this fracture type.

Locking compression plates follow a new concept in fracture treatment.

Surgical Technique

Supine positioning

Place arm abducted in supine position on the operating table

Approach to the ulna

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Skin incision

The Skin incision is along the subcutaneous border of the ulna, between the

olecranon process and the ulnar styloid process.

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Dissection

The dissection should be carried out between the flexor carpi ulnaris and the

extensor carpi ulnaris muscles. The internervous plane is between the ulnar and posterior interosseous nerves.

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I ncision of ulnar periosteum

According to the position and length of the plate, a delicate detachment of

muscles from the periosteum is performed.



1 Principles top

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Axial compre ssion is achieved by eccentr ic dr ill ing.

Eccentric drilling In transverse and short oblique fractures of the diaphysis, placement of a lag

screw is not always possible. However, axial compression with help of the plate can be achieved.

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Dy namic compression principle

The holes of the plate are shaped like an inclined and transverse cylinder. Like

a ball, the screw head slides down the inclinated cylinder. Since the screw

head is fixed to the bone via the shaft, it can only move vertically relat ive tothe bone.

The horizontal movement of the head, as it impacts against the angled side of

the hole, results in movement of the bone fragment relative to the plate, and

leads to compression of the fracture.

2 Monteggia lesions: General considerations top

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In the adult displaced Monteggia lesion, anatomical reduction and stable

fixation are mandatory.

The ulna fracture must be anatomically reduced in order to ensure accurate

reposition of the radial head.

Once operative fixation is achieved, the surgeon must ensure the stability of the radial head, preferably under image intensification.

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Instability of the radial head or incomplete reduction usually suggests a

malreduction of the ulna fracture.

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3 R eduction of the radial head top

Spontaneous reduction

Usually reduction of the radial head spontaneously follows anatomical

reduction of the ulna (>90%).

Open reduction

In the case of incomplete reduction or persistent luxation (<10%), soft tissue

interposition (joint capsule, annular ligament) has to be suspected and further investigated.

Approach to the radial head

Boyd approach or separate incision by lateral approach to the radial head.

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Stabilization of radial head

The interposed soft tissue structure is reduced and sutured if possible. In cases

of late reconstructions a strip of forearm fascia can be used as a new annular ligament.

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4 Definitive fixation top

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I nsert 1st screw

The prebent plate is fixed with one screw to one of the main fragments. A

reduction clamp is placed on the opposite fragment.



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I nsert 2nd screw eccentricall y

A second screw is inserted eccentrically (yellow drill sleeve) in the oppositefragment.

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T ighten screw

By tightening the eccentrically inserted screw, unilateral axial compression is

achieved.

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Add additional screws

To increase axial compression, a second screw can be placed eccentrically in

either fragment.

When the second screw is tightened, the first screw needs to be loosened toallow the plate to slide on the bone.

All other screws are inserted centrically (green drill sleeve) and do not serve

to increase compression.

Functional aftercare

Because of the dislocation of the radial head, aftertreatment in Monteggia

fractures might differ a little from the usual functional aftercare.

Following stable fixation of the ulna, postoperative treatment might consist inimmobilization in a long cast for 3 weeks (allowing the disrupted ligaments to

heal) with intermittent elbow-mobilization assisted by physiotherapy. The

operated arm is elevated and active mobilization of fingers and wrist is startedwithin the first week.

X-ray control

Postoperatively, after 6 weeks, after 12 weeks and after 1 year.

ÄWeight-bearing³ (in accordance with radiographic assessment after 6 weeks)at approximately 8 weeks after surgery.

Removal of implant

Removal of a plate on the lateral aspect of the ulna by stab incisions

On the forearm the issue of implant removal is controversial. As radius andulna are not weightbearing bones and as removal of plates can be a demanding

procedure, implant removal is not mandatory. Furthermore, there is a risk of

refracture not to be neglected (1/2).

The general guidelines (3) today are:

y removal only in symptomatic patients, possibly only on the ulna as

the ulna is the more exposed boney removal not earlier than 2 years after osteosynthesis

y minimally invasive removal by stab incisions for screws and plate

is to be preferred to complete open approach to the plates, if plate position does allow such a manoeuvre

NEUTRALIZATION WITH LAG SCREW

1 Principle top

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N eutralization plate

As a lag screw osteosynthesis on its own is not able to bear weight andshearing forces, a protection or neutralization plate has to be added to allow

early mobilization.

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Lag screw

Observe the optimal inclination of the screw in relation to a simple fracture

plane.

a) shows a lag screw oriented perpendicular to the fracture plane. This is an

ideal inclination in the absence of forces along the bone axis.

b) shows an inclination half way between the perpendicular axis to the

fracture plane and to the long axis of the bone. This inclination is better suitedto resist compressive load along the bone long axis.

2 Insertion of Lag screw top

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Drill gliding hole

To insert a 3.5 mm lag screw, a gliding hole is drilled with the 3.5 drill bit a s

perpendicular to the fracture line as possible.



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Drill thread

Insert a drill sleeve and drill the thread in the far cortex with the 2.5 drill bit.

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T ap the hole

Tap the hole in the cortex with the 3.5 tap (exception: self-drilling screws).

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I nsert lag screw

Insert and tighten the first lag screw.

Insert a 2nd lag screw to secure a large wedge fragment in the same manner asthe first screw.

3 Application of 3.5 plate top

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Determining length and contouring of plate

Plate length is determined by the fracture pattern and location. If possible 3

holes proximal and 3 holes distal to the fracture should be used.

If necessary, use bending pliers to contour the plate to fit the anatomy of the bone (radius).

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A pplication of the plate

The plate is applied to the bone with centrically drilled 3.5 cortex screws.

Note that the plate screws do not interact with the previously placed lagscrews.

monteggia technique

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