Implant removal after fracture healing

Abstract

A frequently asked question to trauma and orthopaedic surgeons is whether and if yes, when an implant will be removed? Although implant removal after fracture healing is daily practice, a scientific basis doesn’t exist. All studies in this thesis were performed to unravel the facts and fiction of implant removal since there still is debate about the indications, complications and clinical outcome of implant removal. Indications for implant removal after fracture healing are diverse and most publications present retrospective studies, case reports or expert opinions. Opinions and habits vary between surgeons (e.g., differences between countries), patients (e.g., children and adults) and implants (e.g., plates versus nails). Accepted indications for removal used to be the assumed risk of metal corrosion, allergic reactions, bone atrophy and carcinogenesis. But the lack of proof that implants damage health and the observed technical problems along with the introduction of titanium alloy implants, made surgeons became less enthusiastic to remove implants. Currently, the main indications are generally ‘relative’ and driven by patient’s complaints and symptoms. The results of a national survey among all members of the Dutch Trauma Society and Dutch Orthopaedic Trauma Society, confirm that the opinion and attitude towards implant removal after fracture healing are diverse, even in a small country as the Netherlands. Also in children implant removal is topic of a worldwide discussion. Paediatric fracture treatment differs because of rapid fracture healing and the growing skeleton. Implants preferably used are Kirschner-wires, elastic stable intramedullary nails and/or screws. The results of a retrospective study in 298 children showed that standard removal resulted in less than 10% complications. As in literature, most complications were minor and transient. Only four refractures (1%) appeared. Titanium alloy implants have become popular because of better biocompatibility and mechanical properties. Unfortunately, removing titanium implants can be very difficult due to bone adherence. In a sheep model the ease of removal of stainless steel, standard titanium and polished titanium nails were compared. Surface polishing significantly reduces pull-out forces required to remove standard titanium nails, comparable to forces observed in stainless steel. A prospective clinical cohort study was performed in five hospitals to describe the main complications and clinical outcome of implant removal after fracture healing. Most patients (n=288) had symptoms related to the implant and expected them to improve after removal. The main complaints were ‘pain’ and ‘limited joint mobility’. The overall complication rate was 30%. The percentage was higher in the lower extremity (37%) than in the upper extremity (22%; p=0.005), resulting in a 2.8 times higher complication odds (95% CI: 1.57-5.06). The main complications in the upper extremity were sensory nerve injuries (6%) and wound infections (6%). In the lower extremity postoperative bleedings (19%) - especially after nail removal (femur nail 21%, tibia nail 22%) - and wound infections (10%) were seen. A significant improvement of pain, limited joint mobility and muscle weakness was observed. The overall satisfaction with the outcome was very high for both surgeon and patient, since 97% would decide for the same procedure again.