Modular prosthesis replacement for comminuted and unreconstructable radial head fractures

Abstract

Objective To analyze the results of modular prosthesis replacement for treatment of comminuted and unreconstructable radial head fractures associated with other elbow fractures and sof-tissue injuries. Methods From November 2009 to March 2011,22 patients with comminuted radial head fracture of Mason type Ⅲ were treated with Acumed modular prosthesis replacement. Repair of collateral ligaments and associated elbow fractures was carried out simultaneously.They were 16 men and 6 women,with an average age of 41.5 years (from 21 to 62 years).The left side was involved in 9 cases and the right in 13.One patient was associated with posterior olecranon fracture-dislocation of Monteggia type Ⅱ,13 with elbow terrible triad,one with elbow dislocation but without coronoid process fracture,3 with Essex-Lopresti injury and 4 with medial collateral ligament injury.The coronoid process fracture was fixated with Kirschner wire and the proximal ulnar fracture with plate and screw.Hinged external fixators were used in 2 cases of elbow terrible triad.Patients were evaluated by the Mayo Elbow Performance Score (MEPS). Results The follow-ups averaged 12.95 months ( range,6 to 22 months ).One patient had disturbed elbow flexion of less than 90° due to prosthesis overstuffing,one patient had elbow instability in spite of full range of motion gained due to prosthesis understuffing,and one patient had elbow ankylosis at elbow flexion of 70° with a heterotopic ossification bridge.The results in the other 19 patients were good to excellent. Their average flexion was 131.5°±4.4° (from 130° to 140°),average extension 5.4°±6.3° (from 0 to 20°),average range of extension-flexion motion 126.1 ° ± 7.7° ( from 120° to 140°),average pronation 81.6° ± 6.4° ( from 70°to 90°),average supination 85.6° ± 3.1° (from 80° to 90°),and average range of rotation 167.2° ± 8.2°(from 150° to 180°).Their mean postoperative MEPS score was 94.2 ± 5.1 points (from 85 to 100points). Conclusions The Acumed modular radial head prosthesis offers 200 standard combinations (10left and 10 right stem options with 5 diameters and 4 collar height options) to accommodate different sizes and provide proper restoration of the overall length of the radius,replicates natural radial head geometry,provides improved articulation with the capitellum,prevents loosening and maintains the proper relationship between the radial neck and the plane of the head.Consequently,it is a fine treatment option for radial head fractures of Mason type Ⅲ complicated with additional elbow fractures and soft-tissue injuries,but it can also lead to complications. Key words: Elbow joint; Fractures; Surgical procedures, operative; Arthroplasty, replacement