Metabolic conditions can alter bone metabolism and result in suboptimal conditions after total joint arthroplasty (TJA). They increase the risk of intraoperative and postoperative periprosthetic fractures, stem subsidence, aseptic loosening, and decrease bone density around the prosthesis.
Antonia F. Chen, MD, MBA, director of Research for the Division of Adult Reconstruction and Total Joint Arthroplasty in the Department of Orthopaedic Surgery at Brigham and Women’s Hospital, Christina Liu, MD, a resident in Orthopaedic Surgery at Massachusetts General Hospital, and colleagues recently detailed in JBJS Reviews the effects of metabolic disease on TJA outcomes. They also reviewed the literature on preoperative management of osteoporosis, vitamin D deficiency and diabetes mellitus.
Given rising healthcare costs, the transition to bundled payments, and the increasing use of quality metrics, the authors note orthopedic surgeons have ethical and financial incentives to collaborate with other physicians on preoperative optimization.
Steps in preoperative management of osteoporosis by surgeons, and considerations for adjusting arthroplasty procedures, are:
- At the initial evaluation for elective TJA, the patient’s score on the Fracture Risk Assessment Tool (FRAX) or similar tool should be calculated
- Blood and urine tests (detailed in the article) can rule out secondary causes of osteoporosis to allow earlier intervention; many of them are routine in primary care
- General guidelines don’t recommend delaying TJA until osteoporosis treatment is completed because it can last months or years; the important point is to refer the patient to an endocrinologist, geriatrician or primary care physician to initiate treatment and prevent further progression
- In case an intraoperative fracture occurs, surgeons should be prepared with additional plates, screws, wires, stems and augments
- The use of cement and certain implants, such as short stems in total knee arthroplasty (TKA), may minimize the rapid bone loss that is common after TJA
- A cemented femoral stem reduces the risk of early periprosthetic femoral fracture after total hip arthroplasty
- Surgeons should take extra care during the phases of TKA in which fracture is likely to occur: knee hyperflexion, intercondylar notch preparation, tibial keel preparation, trialing and impaction of the final components
Vitamin D Deficiency
Although closely linked to osteoporosis, vitamin D deficiency is a separate condition with its own management pathway. The most common treatment is oral supplementation with vitamin D. The addition of calcium carbonate or calcium citrate may also be considered.
Key points about preoperative optimization of patients with diabetes are:
- Both the treatment of insulin resistance and achievement of tight glycemic control are extremely challenging, so patients with poorly controlled diabetes should be referred to a diabetes care team prior to surgery
- Based on limited evidence, a typical goal for preoperative hemoglobin A1c is ≤8%; if that target can’t be achieved, a preoperative blood glucose level of <200 mg/dL is recommended
- In patients age 65 or older, especially those with frailty or dementia, the diabetes care team may consider less aggressive glucose management because hypoglycemia is linked to falls, fractures and increased risk of death
- Postoperative management of diabetes is equally important, as alterations in diet and the physiologic stress of surgery can affect glucose levels; an inpatient diabetes service should be consulted upon postoperative admission, and outpatient specialty follow-up should be arranged within one month of discharge or earlier if there has been a change in glycemic medications or glucose control is not optimal at discharge
Formalizing the Process
The CDC, in collaboration with advocacy teams from the American Academy of Orthopaedic Surgeons and the American Association of Hip and Knee Surgeons, is exploring the possibility of creating procedure codes to increase the value of perioperative optimization.