Use of a polymethacrylate radial head spacer in temporary reconstruction of complex radial head fracture with associated elbow instability.

Radial head replacement in complex elbow fractures (Mason III) with either bony or ligamentous injuries or interosseous membrane rupture is unquestionable. Actual modular and metallic prosthesis ease the mounting technique and ensure durability. Nevertheless, these types of prostheses are not always available in a short time in our daily practice. We present the use of a transient polymethacrylate spacer as an alternative in nonreconstructable complex radial head fractures with a unstable elbow. We assessed 38 patients between 2006 and 2007, with a median follow-up of 53.8 months. We included 14 Mason IV; 8 Monteggia (posterior); 7 Mason III with either associated medial collateral ligament or interosseous membrane injury; 6 elbow triads; and 3 Essex-Lopresti lesions. With the Mayo elbow performance score and the disabilities of the arm, shoulder, and hand score questionnaire, we assessed the functionality. Anatomic results were evaluated with x-ray scans of the elbow and wrist using the Broberg and Morrey and the Knirk and Jupiter scales. Functional results were as follows: 14--excellent, 14--good, 8--fair, and 2--poor. Assessment through disabilities of the arm, shoulder, and hand score questionnaire was 18.7% in average. There was a statistically significant relationship between joint stability and motion. Of the patients, 70% showed mild or moderate chondromalacia of the capitellum and 90% showed osteolysis on the proximal metaphysis of the radius, both events related to follow-up time but not to pain or range of movement. Of the cases, 30% showed heterotopic calcifications and 35% showed moderate arthrosis between the ulna and the humerus. None of the patients presented wrist arthrosis. Complications were 1 deep infection and 1 spacer luxation because of fatigue and ulna plate rupture (Monteggia posterior). In 6 patients, we had to remove the spacer because of pain and/or functional limitation, and 2 of these patients remained with moderate valgus instability after removal. We consider using this type of spacer in those complex situations in which the definitive prosthesis is not available, because it is cheap and resistant to axial and valgus forces. In spite of the good anatomic and functional results obtained and the low complication rate, we firmly think that the spacer should only be used in a transient manner and in special situations, although in this series, only 8 of the 38 patients have accepted to have the spacer removed.