Surgical Trends for Managing Knee Osteonecrosis: A 2010 to 2020 United States Nationwide Study

BACKGROUND

Knee osteonecrosis (ON) is rare, with an estimated incidence of 0.01-0.17 per 1,000 person years. Our study aimed to do the following: 1) quantify total operative procedures with rates normalized to the United States population; 2) compare arthroplasty versus joint-preserving procedural trends; and 3) determine rates of specific operative techniques/demographics in patients aged <50 versus >50 years.

METHODS

Using a nationwide database, 8,269 patients diagnosed with knee ON underwent surgical treatment from 2010 to 2020. Documented surgical procedures included total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and core decompression. Primary outcomes included procedural utilization with subanalyses comparing arthroplasty versus joint-preserving procedures, and age-stratified by under/over 50 years. Linear regressions were evaluated for trends in procedural volumes over time.

RESULTS

From 2010 to 2014, 0.54% of all knee procedures were to treat ON compared to 0.71% from 2015 to 2020 (P < .001). Overall rates of TKA (85.4%) and UKA (10.3%) far exceeded rates of joint preserving procedures (4.3%). Comparing 2010-2014 with 2015-2019, joint-preserving procedures proportionally increased (0.7 to 5.0%, P < .001). Patients <50 years had significantly more joint-preserving procedures (19.5 versus 2.7%). Overall, TKA was the most common procedure (7,062; 85.40%), following by UKA 853; 10.32%) and core decompression (354; 4.28%).

CONCLUSION

To our knowledge, this is the first study to characterize surgical trends in management of knee ON. Overall surgical volume for knee ON has continued to increase, outpacing population growth. Patients who have knee ON are most commonly managed with arthroplasty procedures, specifically TKA. Younger aged patients (<50 years) are more likely to undergo joint-preserving procedures, namely core decompression.

A rare avascolar osteonecrosis of the knee related to biphosphonate treatment in a patient with metastatic breast cancer

Bisphosphonates are widely used both in the multidisciplinary management of bone metastases, especially osteolytic lesions from solid tumors or multiple myeloma, and of osteoporosis.Aseptic osteonecrosis, especially of the jaw, is among the well-known, although uncommon, side effects of bisphosphonates. Osteonecrosis of other bones has been very rarely reported with the use of bisphosphonates.We describe a rare case of osteonecrosis of the distal femur associated with the use of bisphosphonates in a 74 years old female patient with metastatic breast cancer.