Complications of total hip replacement
Total hip replacement represents one of the most successful procedures in orthopedic surgery. It is able to restore quality of life, and the recovery is usually quicker that it is for a total knee replacement. There have been multiple advancements in hip replacement over the years but nevertheless, it remains a major surgery. There are potential complications that can occur after a total hip replacement. We would consider some major complications here. We have grouped these in three categories: early post-operative complications, late post-operative complications, and the complications that can occur at any time. We continue this week with late post-operative complications.
Late post-operative complications
Loosening: Hip replacement components can be fixed with or without cement with the end-goal of stable component fixation. There are cases where rigid stability is not obtained with cemented or cementless components. Loose implants occur in this scenario. A loose socket component can cause groin pain, a loose thigh/femoral component can cause thigh pain. The pain is usually mechanical (walking, activity-related). Risks factors include smoking, poor bone quality, and improper surgical technique. If the pain from a loose prosthesis is significant, it can warrant a re-do surgical procedure to implant better fitting components.
Component failure: This is a rare occurrence that can result in breakage of the hip replacement femoral component, breakage of the ceramic components (head or liner) and breakage of the acetabular component. Component failures can be due to trauma, defective components, or metal reactions. These failures typically cause pain and limitations in functioning. Management is surgical and involves re-do surgical interventions to replace the failed component (or components) and restore appropriate function.
Osteolysis: This is a complication that is not as common today as it was in the past. This usually occurs due to wear of the plastic component (polyethylene liner) in a hip replacement. The microscopic plastic wear particles can cause a biological reaction that can result in resorption/loss of bone stock. This can result in hip pain, fractures, loose components and even dislocations. Significant osteolysis is best managed with revision surgery. This can involve exchanging the plastic component and the head component of the hip replacement. It can also involve complete revision of all components if they are loose or unstable. If osteolysis is only on imaging (x-rays, CT scan) but without symptoms, the osteolysis can be regularly checked with x-rays if not particularly large. Large osteolytic lesions without symptoms would merit a discussion of risks and benefits of revision surgery in the absence of symptoms. Thankfully, the plastic liner used in modern hip replacement is more resistant to wear and the ceramic heads now commonly used also result in decreased wear.
Metallosis: This is a rare complication that can develop from metal reactions in a hip replacement that result in metal particles being shed into the tissues around the hip replacement and into the blood. These reactions can occur at different metal junctions in a hip replacement. Metallosis can cause fluid collections in the hip that can destroy the soft tissue in and around the hip. These can result in pain, hip dislocations and even component failure. Symptomatic metal reactions/metallosis will need re-do surgery. However, the complications rates from these surgeries are higher than from re-do surgeries for other reasons. Before embarking on a re-do surgery for metallosis, laboratory studies would be obtained to check metal levels, and infection markers. An MRI and a hip aspiration might also be obtained. The surgery typically involves revising the failed component and can range from just a head and plastic liner revision to full revision of the entire hip replacement construct.
Dr. Oluwaseun Akinbo M.D. is an orthopedic surgeon at HaysMed. For more information, https://www.haysmed.com/oluwaseun-akinbo/.