Chondral lesions are small areas of damage to the articular cartilage. Articular cartilage is the soft, smooth covering of the bone that allows the joint to move smoothly and without pain. Chondral lesions of the hip can be a source of elusive pain and often lead to severe osteoarthritis, particularly in patients with femoro-acetabular-impingement, or FAI, due to progressive degenerative changes in the hip. These lesions have conventionally been treated much like lesions in other joints, but the spherical nature of the hip makes it unique and not necessarily conducive to the same outcomes as other joints treated in the same way.
A recent study sought to compare the results of patients with chondral lesions of the hip with FAI who were treated with a technique known as microfracture – a technique often used for the knee – versus those treated with micro-fragmented autologous adipose tissue transplantation.
Microfracture, a cell-based therapy that stimulates the marrow, has been shown to be advantageous in the knee when chondral defects are small. However, there is less evidence of its benefits in the hip. The technique has been associated with the formation of cysts and has appeared to be limited in its ability to provide long-term benefits and prevent osteoarthritis.
The researchers of this recent study comparing microfracture and micro-fragmented autologous adipose tissue transplantation focused on 194 patients who had undergone one of the two procedures at the same center between 2014 and 2015. The study included 108 males and 86 females, and the average age for these participants was 38 years.
Of the 194 subjects, 77 underwent arthroscopic microfracture, and 117 underwent arthroscopic micro-fragmented autologous adipose tissue transplantation. The average size of the lesions was slightly larger in the former group (3.6 square centimeters) compared to the latter (3.2 square centimeters).
The researchers took into account patients’ hip function, as measured with the modified Harris Hip Score, 6 months, 1 year, and 2 years after the patients had undergone their procedure. Results showed that both techniques for addressing chondral lesions of the hip helped patients in the short-term. Indeed, clinical status was significantly improved in patients who underwent the arthroscopic microfracture as well as those who underwent arthroscopic micro-fragmented autologous adipose tissue transplantation 6 months and 1 year after their procedures.
The difference in the value of the two procedures was discovered at the 2-year follow-up, when the arthroscopic microfracture group displayed a progressive decrease in hip functionality, with 10 of the patients requiring total hip arthroplasty. Patients who had undergone arthroscopic micro-fragmented autologous adipose tissue transplantation, on the other hand, continued to demonstrate positive clinical outcomes, and none of them required total hip arthroplasty.
The data from this study suggest that while arthroscopic microfracture may be reasonable as the treatment of choice for small chondral defects of the acetabulum and femoral head and may provide promising results in the hip, arthroscopic micro-fragmented autologous adipose tissue transplantation may be superior when considering long-term hip functioning.
Further, this study provides evidence that this newer technique is not only effective but also safe for patients with chondral lesions of the hip. Future research will likely help to distinguish clinical meaningful differences in the different treatment options for chondral lesions and to identify the best cell sources and protocols for cell-based therapies to improve patient outcomes.
- Fontana A. Adipose tissue derived mesenchymal stem cell therapy for the treatment of chondral lesions in the hip: A 2 years follow-up comparison study with microfractures. https://www.orthohealing.com/procedures/lipogems/pdf/Fontana poster_ORS_2017.pdf.
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- Logan ZS, Redmond JM, Spelsberg SC, Jackson TJ, Domb BG. Chondral Lesions of the Hip. Clin Sports Med. 2016;35(3):361-372. doi:10.1016/j.csm.2016.02.005