22/11/2012
AO Technical Commission Approved

LCP Ulna Osteotomy 2.7 System

Ulna impaction syndrome (or ulnocarpal abutment syndrome) is a degenerative condition related to excessive load bearing across the ulnar aspect of the wrist, which results in chronic impingement of the ulnar head against TFCC, lunate and triquetrum. This chronic impingement further results in wrist pain, swelling, limited range of motion, and diminished grip strength. In most cases, a positive ulna variance causes this ulnocarpal impaction syndrome. Distal radius fractures with radius collapse are also a common problem with a secondary painful positive ulna variance. Depending on stage and patient symptomatology, the treatment includes an ulna shortening osteotomy. However, the common complications in ulna osteotomies are hardware irritations as well as delayed union or nonunions.

The LCP Ulna Osteotomy 2.7 system is ideal for shortening osteotomies of the ulna. It allows accurate oblique or transverse osteotomy cuts and correct restoration of bone alignment, and uses a smooth and low profile plate design that minimizes hardware irritation. The system consists of plates in two sizes (short plate 6-hole, and long plate 8-hole) (see figure),

Five drill templates (Fig 3) with predefined shortening lengths
(2.0 mm/2.5 mm/3.0 mm/4.0 mm/5.0 mm) for transverse or oblique
cuts, ...

a saw guide for oblique 45 cuts, 2.0 mm K-wire with drill
tip, five parallel saw blades for transverse cuts, and five parallel saw
blades for oblique (45) cuts.


It is important to understand the concept of the system: First of all, either a transverse or oblique osteotomy has to be selected. Screw holes for the plate need to be drilled at the right place before the osteotomy is done. A special tool helps get a precise parallel osteotomy cut, but the instrument will only work on a flat surface. A bent or curved bone will require a larger incision. If the plate toggles, either the bone needs to be flattened or the plate should be positioned more proximally. For an oblique cut, a guide is used for marking the osteotomy and then removed. The correct usage of the jig is important for accurate shortening, and proper rotation alignment needs to be ensured. Sufficient interfragmentary compression (good friction of the whole osteotomy surface) is needed. In oblique osteotomies, the adequate length of the lag screw (screws should be used 1 mm longer than measured) is mandatory for a good compression. Depending on the bone quality, the type of patient (eg, very muscular persons may require an 8-hole plate instead of a 6-hole plate), and the amount of shortening, a sufficient number of bi-cortical locking screws has to be used. In patients with hard bone, it is advisable to use the dedicated tap.


In summary, the LCP Ulna Osteotomy 2.7 system leads to a lower complication rate, reduced non-union rate, and reduced postoperative pain, as it allows for a shorter incision, more precise cutting, better alignment, and minimizes hardware irritation, which greatly reduces the need for plate removal, if the correct surgical technique is followed.

Case 1: Distal radius fracture

Cases provided by Doug Campbell, Leeds, UK; Ladislav Nagy, Zurich, Switzerland; and Juan Gonzlez del Pino, Madrid, Spain.

A 69-year-old female patient had suffered a right distal radius fracture one year earlier, and received conservative management. Symptoms included pain and impaired function about the wrist and forearm, with decreased forearm rotation. Painful DRUJ (DASH: 34, PWRE: 29).

 The x-ray showed ulna variance of +3 mm.

Normal sagittal and coronal alignment of the distal radius. Surgery was performed, with the amount of shortening being 4 mm. Transverse cut.

The outcome included bone healing at 4 months, pain relief and improved forearm rotation at 2 months. Early osteotomy site remodeling: 6 months. Final remodeling: 12 months. Outcome at 1 year and 6 months: DASH: 11, PWRE: 13.


Case 2: Painful ulno-carpal abutment

A 32-year-old man suffered torsional trauma about the right wrist, with TCFF rupture. A failed arthroscopic repair had taken place. Constitutional ulna plus. Symptoms included pain and impaired function about the wrist and forearm. Painful DRUJ (DASH: 22, PWRE: 21).

 

The x-ray showed ulna variance of +3 mm (see figure). Surgery was conducted with an amount of shortening of 4 mm, transverse cut.

Postoperative outcomes (see figure) included bone healing at 4 months, and pain relief at 1 month. Early osteotomy site remodeling: 7 months and final remodeling: 12 months. Outcome at 14 months: DASH: 9. PWRE: 5


Case 3: Oblique osteotomy

A 48-year-old female nurse had a diagnosis of a degenerative central TFCCrupture, with chronic ulnocalpal abutment.
The amount of correction required was 2.5 mm. The preoperative x-ray showed positive ulnar variance.

Images from the operation and results at four months are shown (this and next figure).

 

This Figure: Drill template introduced for shortening, drill holes prepared (bolts), and saw guide used for the oblique cut (45 degrees). Once the bone slice was removed, the saw guide was replaced with the proximal plate, and screwed in (lag screws and locking screws).

Figure ab) Postoperative x-ray.

Figure cd) Images of the healed osteotomy four months post-op.

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