For a physician with limited treatment procedures available, finding the right solution for young patients with cartilage defects in the hip may present a complex problem. Cartilage repair techniques have shown promising results in other joints, but literature on the hip joint is still very restricted.
A study published in September 2012 led a systematic review that included case studies, case series and clinical studies. According to this review, a variety of techniques have been reported for the treatment of cartilage defects in the hip, however, most studies suffered from lack of either a control group or a large number of patients.
The treatment for hip cartilage defects continues to be the hip arthroplasty, but because of the risks and limitations associated to this type of surgery, it is not usually applied to young patients. Nonetheless, the operative procedures evaluated such as Autologous Chondrocyte Implantation (ACI), Microfracture, Synthetic treatment, Mosaicplasty, Osteochondral allograft transplantation and Articular cartilage repair, showed a good foundation for treatments that could provide any kind of relief or some kind of delay on the progression of this condition:
On ACI, the authors suggested that arthroscopic debridement has limited utility in treating chondral lesions of the hip, especially in lesions less than 3 cm2 due to the fact that the patients had the worst outcomes.
On Microfracture, it has shown from both a clinical and biologic standpoint. However, the available literature did not account for external variables so, further well controlled studies will be necessary before any definitive conclusions can be drawn.
On the Synthetic treatment, the most interesting aspect was the use of an antegrade technique to place the graft flush with the acetabular articular surface. This technique could theoretically be used with several other grafts.
On Mosaicplasty the technique can be completed with multiple osteochondral plugs from the patient and provides a useful tool for the treating surgeon, but it should be noted that half of the patients did not have problems before an injury and mosaicplasty was done.
Osteochondral allograft transplantation has also been shown to be a successful technique for the treatment of cartilage defects. However, the studies show all the research needs to be continuously redefined in order to determine the specific etiologies of hip pathology that respond well to allograft transplantation.
Last, but not least, on the Articular cartilage repair the technique shows to be able to treat large delaminated full-thickness acetabular cartilage and potentially prevent its progression.
Later, results from a study published in March of 2016 indicated the sensitivity and specificity of 3T-MRI for the identification of grade 3 and 4 chondral defects in the hip. The 3T-MRI provides a higher spatial resolution and image contrast, resulting in better visualization of anatomic structures than the common 1.5T-MRI.
The study included 606 patients who underwent 3T-MRI and had lesions confirmed and graded with the Outerbridge system. Researchers used arthroscopic findings as the gold standard in order to determine the 3T-MRI predictive value. The average time between the MRI and the arthroscopy was 1.9 days.
Researchers observed the sensitivity, specificity, positive predictive value and negative predictive value when detecting the femoral head defects using MRI and the results were 61%, 58%, 29% and 84%, respectively; as for chondral defects in the acetabulum, MRI showed sensitivity, specificity, positive predictive value and negative predictive value of 80%, 41%, 42% and 79%, respectively.
In conclusion, this study showed that 3T MRI had the specificity required to identify chondral defects, similar to what has been previously reported. With a low positive predictive value, MRI may be most useful in ruling out cartilage lesions. When compared with femoral head defects, MRI showed an increased sensitivity when identifying acetabular defects.