Short- to Mid-term Results of Patient-Specific Polymethylmethacrylate Radial Head Prosthesis in Complex Radial Head Fractures Using 3-Dimensional Mold System.

ABSTRACT

Background: We used antibiotic-impregnated polymethylmethacrylate (PMMA) bone cement to make a patient-specific radial head prosthesis (RHP) by applying the 3-dimensional (3D) designing technique in patients with Mason types 3 and 4 radial head fractures. The aim of this study is to report the short- to mid-term outcomes of this procedure. Methods: This is a prospective study of all patients who underwent a patient-specific PMMA bone cement RHP at our institute over a 1-year period from May 2017 to June 2018. The outcome measures included range of motion, grip strength, visual analogue scale (VAS) for pain at rest and at activity, disabilities of arm, shoulder and hand (DASH) score and Mayo elbow performance index (MEPI). Radiographs of the elbow ere obtained at final follow-up and any complications were also recorded. Results: Our study included eight patients with a mean follow-up of 18 months (13-20 months). The mean arc of extension-flexion and supination-pronation of the operated side was 86% and 96% of the unaffected side, respectively. Mean grip strength was 86% of the unaffected side. The mean VAS for pain at rest was 0 and during activity was 2 out of 10. The mean DASH score was 8 out of 100 (0-22), showing minimal disability and ability to cope with most living activities. MEPI showed four excellent, three good and one fair result. One patient complained of proximal forearm pain that appeared 1 year after surgery. No patient complained of ulnar nerve symptoms requiring intervention. No RHP was removed during the follow-up. Conclusions: PMMA RHP can be used safely as an alternative to metal prostheses to restore valgus and axial stability of the forearm. The use of 3D printing optimised the design and surgical technique of radial head arthroplasty, and we need further studies to assess the long-term follow-ups. Level of Evidence Level IV (Therapeutic).