(click on the image for a larger view)

Introduction: Unilateral fixators are valuable external fixation devices used in the management of foot and ankle disorders. These fixators are unique in their size and design characteristics. They provide stability by utilizing half-pins in a linear configuration. Mini and small fixators are commonly used in the small bones of the foot. Whereas, large fixators are typically used in the hindfoot and ankle. Unilateral fixators are manufactured in fixed or articulated constructs. These fixators may be used as a monoplanar distraction or compression force. Articulated fixators may be utilized for multiplanar motion allowing for stability. Unilateral fixators lack stability in the sagittal plane and therefore, immediate post-operative weight bearing is not indicated.

Indications: Unilateral fixators are commonly utilized for fracture management (open/closed) and congenital deformities. Indications may include: primary joint fusions, bone lengthening, infection, corrective osteotomy stabilization, arthrodiastasis, soft tissue envelope does not allow for internal fixation, nonunion or a history of a contralateral nonunion, revisional intervention, combined internal/external fixation and bone transport.

Contra-indications: When considering utilizing any type of external fixation device, the following concerns should deter application: noncompliance, lack of participation, psycho/social issues, hygiene, lack of understanding.

Case 1: 50 year old male tobacco user with a history of a nonunion first metatarsocuneiform joint arthrodesis on the contralateral limb requiring multiple interventions. Post-Op AP

Column Lengthening Example Column Lengthening Example     Example 1: Evans Lateral Column Lengthening Note protection of the calcaneocuboid joint, a common area of post-operative complications with traditional bone graft Evans procedures. Post-Op Lateral Post-Op AP

 

Case 2: Brachymetatarsia: Congenital Short 2nd Metatarsal (click on the images below for a larger view) Pre-Op Pre-Op Post-Op

Case 4: Trauma: Motorcycle Accident Significant navicular crush injury with dorsal foot fracture blisters. (click on the images below for a larger view) Motorcross Accident Pre-Op AP Motorcross Accident Pre-Op Lateral     Motorcross Accident Post-Op Image Motorcross Acc. Post-Op     Motorcross Accident Post-Op Lateral

 

Case 5: Failed Bunion Surgery: The patient had a first metatarsocuneiform joint arthrodesis performed two years earlier with subsequent hardware removal. The patient had persistent pain at the distal medial first metatarsal. Moreover, the patient had sub-metatarsal two pain due to a shortened first metatarsal with mild elevation and incomplete intermetatarsal angle reduction. The patient requested revisional surgery to alleviate the bunion pain, second toe digital contracture and sub-metatarsal two pain. Procedures performed included the following: first metatarsal osteotomy, first metatarsophalangeal joint soft tissue re-balancing, second proximal interphalangeal joint arthroplasty with plantar plate repair and application of multi-planar mini-rail external fixator. (click on the images below for a larger view) Failed Bunion Immediate Post-Op Lateral   Failed Bunion AP - What Was Accomplished Failed Bunion Lateral - What Was Accomplished What was accomplished? Simultaneous intermetatarsal and first metatarsal shortening reduction. Restoration of Metatarsal parabola. Painfree gait

Conclusion: Unilateral external fixators can provide an excellent source of stability for lower extremity fracture management and deformity correction. They may be of particular use when the soft tissue envelope will not allow for internal fixation and when an open wound or "dirty" wound is encountered. As with all forms of fixation, complications do occur. Pin tract irritation and infections are the most common, but preventable complication. Major complications including nonunion, osteomyelitis, neurovascular injury and bone fracture are less common. Unilateral external fixators provide surgeons with an alternative means of fixation and enable patients to participate in their own care. Careful pre-operative planning is important when considering external fixation vs. internal fixation or a combination of both.

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The main business of Vilex is orthopedic and podiatric bone surgery. Vilex® offers a broad range of cannulated screws, locking and conventional plates, small joint implants, a subtalar Arthroereisis implant, and ring and mono-rail external fixation devices. In addition, through United American Medical (UAM, acquired in 2001), Vilex® offers a whole array of power equipment such as wire drivers, drills, and oscillating/reciprocating saws. Internal Fixation Products Cannulated Hemi & Met Head Implant System Mini Cannulated Hemi & Met Head Implants Talus of Vilex (TOV) Subtalar Implants Rail Fixation System The Vilex ez-FIX System The Vilex Plate System Unique Surgical Instruments Power Equipment & Accessories

Vilex® also offers saw blades, guide wires, drills and burrs. All Vilex Internal Fixation products are manufactured in the USA. Call 800.521.5002 for more informatin of visit www.vilex.com today.