LCP Ulna Osteotomy 2.7 System
Ulna impaction syndrome (or ulnocarpal abutment syndrome) is a degenerative condition related to excessive load bearing across the ulna aspect of the wrist, which results in chronic impingement of the ulna head against TFCC, lunate and triquetrum. This chronic impingement can cause wrist pain, swelling, limited range of motion and diminished grip strength. In most cases, a positive ulna variance causes 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 although common complications can include hardware irritations and delayed or non-unions.
The LCP Ulna Osteotomy 2.7 system (Fig 1a) 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. (Fig 1b)
The system consists of five drill templates with predefined shortening lengths (2.0 mm/2.5 mm/3.0 mm/4.0 mm/5.0 mm) for transverse or oblique cuts. (Fig 3) In addition, the system contains a saw guide for oblique 45 cuts, a 2.0 mm K-wire with drill tip, five parallel saw blades for transverse cuts, and five parallel saw blades for oblique (45) cuts (Fig 3)
Technique for usage
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 (Fig 4) is important for accurate shortening, and proper rotation alignment needs to be ensured. Sufficient inter-fragmentary 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 bone quality and the amount of shortening required, 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).
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).
Case 3: Oblique osteotomy
A 48-year-old female nurse had a diagnosis of a degenerative central TFCCrupture, with chronic ulnocarpal abutment.
The amount of correction required was 2.5 mm. The preoperative x-ray showed positive ulna variance.
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