Letter to the Editor of RECOT. “Functional outcomes and eight-year survival of hip arthroscopy in patients with degenerative hip disease” by D. Torres-Perez et al

Dear Editor,

I read the interesting article published in your journal “Functional outcomes and eight-year survival of hip arthroscopy in patients with degenerative hip disease” by Torres et al.,¹ where they evaluated the outcome of hip arthroscopy in 40 patients with degenerative hip disease during the period from 2007 to 2011.

The aim and hypothesis of the study are of clinical interest and applicability, and several observations on this study could be useful for a more critical reading of it.

Material and method

Twenty-five patients (24.5%) were lost to follow-up and 17 (16.6%) did not wish to participate in the study. In total, 41.1% of the individuals operated on who met with the inclusion criteria, could not be assessed at the end of follow-up. This selection bias should have been more emphatically highlighted in the study limitations section since it could have completely modified the outcomes and consequently, the confirmation of the study hypothesis.^2–4

Joint height was not included in radiographic analysis. A joint height under 2 mm, at any point of the joint space, multiplies the possibility of needing a total hip replacement by 9.9 times.⁵ Neither was the presence of osteophyte in the acetabular fossa, subchondral geodes, or grade 3 or 4 chondral lesions indicated. These are poor prognostic signs in studies by the Berne group and the Mayo Clinic.⁶

Results

The establishment of statistically significant differences between patient groups with a small sample size (for example, there were 7 people with previous lower back surgery) should be assessed with great precaution.

Discussion

Although the study was conducted with a group of patients operated on between 2007 and 2011, the final review was made in 2018 or at the beginning of 2019. At this time, different consensuses had already been published on indications for arthroscopic hip surgery in femoroacetabular impingement and degenerative hip pathology.^7–9

Regarding the degenerative pathology, consensus from the Spanish Association of Latin American Arthroscopy indicates that osteoarthritis of the hip is not treated with hip arthroscopy, but that conservative treatment, low impact exercise, physiotherapy and joint injections delay the need for hip replacement more effectively than when treated with arthroscopy.⁸ Logically, consensus is posterior to the period when the patients were treated. However, it is of note that this is not mentioned in the discussion. The article could have been directed to consider whether the results obtained with the series had confirmed what had been established in the consensus.

The revision rate is 17.5%, which indicates that it is comparable to other published series. However, it is not established whether this is a high rate, bearing in mind the percentage of cases lost to the study.

Conclusions

Great caution must be employed with the conclusions in accepting the study hypothesis.

The authors give the impression that hip arthroscopy is an indication in the patient with degenerative hip disease when it is actually a contraindication according to established consensus and scientific publications in the literature.

Prudence in the indication for hip arthroscopy in the patient with generative hip disease should go beyond a history of lower back surgery.

Conflict of interest

The authors have no conflict of interest to declare.