ABSTRACT
Introduction: Metal hypersensitivity affects 10-15% of individuals. Orthopaedic implants contain various metals and, therefore, metal hypersensitivity may impact patient outcomes. Purpose: We report a systematic review of the literature on metal hypersensitivity in patients undergoing foot and ankle (F&A) surgery. Our goal is to provide an overview presenting symptoms, diagnostic methods, treatment, and clinical outcomes. Methods: A comprehensive literature search of Ovid MEDLINE and EMBASE was performed from its inception (01-Jan 1966) to 23-Nov 2021. MeSH search terms on F&A were used including orthopaedic surgeries, metal types, and hypersensitivity. All full-text, English, experimental and observational studies reporting on metal hypersensitivity in the context of foot and/or ankle surgeries using metallic orthopaedic devices were included. Article screening, critical appraisal, and data extraction was performed by two reviewers. Disagreements were resolved by a third reviewer. Results: Fifteen studies were identified, reporting on 45 patients (18 male and 27 female). Median age was 58 years and mean follow-up was 20.8 months. 42 static and three arthroplasty implants were included. In total, 19 patients (42.2%) were diagnosed with metal hypersensitivity to a constituent of their implant, including two (4.4%) patients diagnosed without metal hypersensitivity testing. Twenty-six patients (57.8%) tested negative to their metal implant components. Of the 19 patients allergic to a constituent of their implant, 14 underwent hardware removal and improved. Four patients were asymptomatic and the last was symptomatic, but not revised. Of these, 23 patients retained their hardware (eight with skin reactions) and two symptomatic patients underwent hardware removal. Conclusion: Metal hypersensitivity in the context of F&A surgery is not widely reported. It should be a differential diagnosis in patients who present with hypersensitivity-type symptoms once infection and mechanical failure are ruled out. This data informs a comprehensive algorithm for identifying and treating metal hypersensitivity in F&A patients. Level of evidence: Level IV.
ABSTRACT
BACKGROUND: The evidence for treating acute, unreconstructable radial head fractures in unstable elbows with radial head replacement predominantly consists of short- to mid-term follow-up studies with a heterogenous mix of implants and operative techniques. Data on longer-term patient-reported outcomes after radial head replacement is lacking. QUESTIONS/PURPOSES: (1) What proportion of patients undergo revision or implant removal after radial head replacement? (2) At a minimum of 8 years follow-up, what are the patient-reported outcomes (QuickDASH, Oxford Elbow Score, and EuroQol-5D)? (3) What factors are associated with a superior long-term patient-reported outcome, according to the QuickDASH? METHODS: Between September 1994 and September 2010, we surgically treated 157 patients for acute radial head fractures. We excluded patients where the radial head was excised (n = 21), internally fixed (n = 15), or replaced as a secondary procedure after failed internal fixation (n = 2). A total of 119 patients who underwent radial head replacement surgery for an acute unreconstructable fracture were included, with a mean age of 50 years (range 15 to 93 ± 19 years), and 53% of patients (63) were women. All but two implants were uncemented, loose-fitting, monopolar prostheses, of which 86% (102) were metallic and 14% (17) were silastic. Implants were only cemented if they appeared unstable within the proximal radius. Silastic implants were used in the earlier series and replaced by metallic implants starting in 2000. We reviewed electronic records to document postoperative complications and prosthesis revision and removal. A member of the local research team (THC, CDC) who was not previously involved in patient care contacted patients to confirm complications, reoperations and to obtain long-term patient-reported outcomes scores. Nineteen patients had died at the point of outcome score collection. Of the remaining 100 patients, 80 were contacted (67% of total cohort), at a median of 11 years (range 8 to 24 years) after injury. The primary outcome measure was the QuickDASH score. RESULTS: Of 119 patients, 25% (30) underwent reoperation, with three patients undergoing revision and 27 patients undergoing prosthesis removal at a median of 7 months (range 0 to 125 months). Twenty-one of 30 procedures (70%) occurred within 1 year after implantation. Kaplan-Meier survivorship analysis demonstrated a cumulative implant survival rate of 71%. In the 80 patients contacted, the mean QuickDASH score was 13 ± 14, the mean Oxford Elbow Score was 43 ± 6, and the median EuroQol-5D score was 0.8 (-0.3 to 1.0). After controlling for covariates, we found that prothesis revision or removal (p = 0.466) and prosthesis type (p = 0.553) were not associated with patient-reported outcome, according to the QuickDASH. CONCLUSIONS: The management of acute unreconstructable fractures of the radial head in unstable elbow injuries with radial head replacement has a high risk of reoperation. Patients must be counselled regarding this risk of secondary intervention, of which the peak risk appears to be within 1 year after implantation. Despite this, patients report low disability according to the QuickDASH at a minimum follow-up of 8 years. LEVEL OF EVIDENCE: Level IV, therapeutic study.
