Why Obesity Poses Greater Risks for Surgical Complications
A literature review published in the May issue of the Journal of Arthroplasty attempts to define and identify areas of concern for obese patients undergoing total joint arthroplasty (TJA). “Obesity risk assessment is compounded by the fact that obesity is rarely an isolated diagnosis,” the authors write, “and tends to cluster with other co-morbidities that may independently lead to increased risk such as diabetes mellitus, coronary artery disease, hyperlipidemia, hypertension, and sleep apnea.” Among the authors’ findings:
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- Despite improvements in patient-related outcome measures, all obese patients undergoing total joint arthroplasty are at increased risk for perioperative complications.
- Patients with a body mass index greater than or equal to 40 who undergo total knee arthroplasty are at risk for the majority of perioperative complications.
- Published data on perioperative complications among obese patients undergoing total hip arthroplasty appear to be less clear.
New Procedure Offers Treatment Option for Obese Patients With Knee Pain
Subchondrplasty Joint Preservation Treatment Less Invasive Than Joint Replacement Surgery.
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| MRI of BME-Xray normal From Zimmer Institute |
Subchondroplasty® Procedure is the innovative new joint preservation procedure developed by Zimmer Knee Creations to treat the microfractures that develop just under the joint surface in painful knees. These lesions are similar to stress fractures and develop due to overload of the bones that make up the knee joint.
Rather than replacing the entire knee, this treatment aims to stimulate nature to heal the bone lesion which can lead to reduced knee pain and better knee function. Subchondroplasty is an arthroscopic knee surgical procedure done as an outpatient. This is a safer and less invasive procedure than Total or Partial knee replacement and as such may be carried out in higher risk surgical patients, such as the obese patient, with less fear of an adverse outcome such as infection or blood clot.
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| BML-MRI image From Zimmer Institute |
Bone Marrow Edema (BME), or Bone Marrow Lesions (BML) are thought to cause pain in knees with early or late osteoarthritis. These lesions can only be diagnosed with high resolution 3 T MRI scans. In 2001 Felson identified BME/BML as the strongest predictor of the presence of pain associated with knee OA. They also determined that arthroscopy alone will not predictably relieve knee pain associated with arthritis.
This observation has been confirmed by other investigators. However, the novel Subchondroplasty® Procedure is a percutaneous outpatient intervention that addresses the painful defects associated with subchondral bone marrow lesions (BME/BML). BMLs are related to stress fractures or micro-fractures, that can only be visualized using MRI scans. Left untreated, these defects have been shown to lead to cartilage degeneration, limited function, pain and greater risk for joint deterioration.
Theoretically, mechanical enhancement and/or biologic stimulation of chronically damaged and structurally compromised SubChondral bone, juxtaposed to a region of the joint with deficient cartilage, will relieve Knee pain emanating from the SubChondral bone and slow progression both bone and cartilage deterioration.
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| From Zimmer Institute |
In this minimally invasive, arthroscopically-assisted procedure, navigation instruments are used to inject specialized Ceramic Calcium Phosphate bone filler (Etex), without violating the joint. As the bone filler is resorbed, the pain due to BML subsides as the lesion is replaced with new, healthy bone. The substitution of abnormal bone with healthy bone is the reason patients experience pain relief. The Subchondroplasty Procedure is the first procedure to treat bone-based changes within a painful joint, and addresses an unmet clinical need between early interventions, such as NSAIDs and joint arthroscopy, and total joint replacement. Subchondroplasty was introduced in November 2010. This procedure is now available in the Greater Phoenix area from Makoplasty Surgeon Stefan D. Tarlow, M.D. of Advanced Knee Care, PC.
