Femoroacetabular impingement and the effect of osteochondroplasty on hip osteoarthritis prevention

Key points

1. 01Each patient acted as their own control: one hip had arthroscopy with osteochondroplasty while the identical untreated opposite hip was the comparison.
2. 02Before surgery there were no measurable shape or joint differences between the two hips (all P > 0.05).
3. 03After a mean of 31.9 months, joint space narrowed at all 3 measured points in operated hips but stayed stable in the untreated hips (P < 0.01).
4. 04Advanced osteoarthritis (Tonnis grade 3) rose from 1.7% to 23.2% in operated hips, with no increase in untreated hips.
5. 05The authors describe a Pandora's box opening process, where reshaping the bone may release cartilage and bone debris that drives inflammation and faster degeneration.

How it was conducted

Design

Retrospective single-center review using each patient as their own control

Participants

56 unilateral FAI arthroscopy patients (112 hips), mean age 42.18 +/- 9.16 years

Groups

Operated hip (osteochondroplasty, with labrum and acetabular procedures as needed) vs untreated contralateral hip

Procedures

Femoral osteochondroplasty in all cases, acetabuloplasty in 13 (23.21%), labrum repair in 26 and regularization in 5 of 31 ruptures

Primary outcome

Osteoarthritis progression by joint space width at 3 points and Tonnis classification

Follow-up

Mean 31.9 months (range 2 to 155)

What they found

• No preoperative anatomical differences between operated and untreated hips (P > 0.05), including alpha angle 70.57 +/- 9.51 vs 69.1 +/- 8.9 degrees.
• Surgery corrected the alpha angle in operated hips from 70.57 +/- 9.51 to 49.98 +/- 6.70 degrees (mean correction 20.6 degrees, P = .01).
• Joint space width fell in operated hips at all 3 points: point 1 from 5.30 +/- 1.3 to 3.90 +/- 2.14 mm, point 2 from 4.02 +/- 0.74 to 3.20 +/- 1.72 mm, point 3 from 4.62 +/- 1.09 to 4.03 +/- 1.71 mm (all P < 0.01).
• Untreated hips stayed stable: point 1 5.53 +/- 1.24 to 5.37 +/- 1.24 mm, point 2 4.39 +/- 1.25 to 4.35 +/- 1.18 mm, point 3 4.98 +/- 1.09 to 5.00 +/- 1.79 mm.
• Tonnis grade 3 osteoarthritis in operated hips rose from 1 (1.7%) at baseline to 13 (23.2%) at follow-up, while untreated hips stayed at 0 (0%).
• Overall survival rate (free of Tonnis grade 3 or total hip arthroplasty) was 0.75; hips starting at Tonnis 0 had survival 0.850 vs 0.61 for hips starting at Tonnis 1 (P = 0.07).

Limitations

• Small sample of 56 patients from a single center with a retrospective design.
• Mean age of 42 years may limit how far the findings extend to other age groups.
• Labrum status was not determined in the untreated contralateral hips, so the two sides were not characterized identically.
• Mean follow-up was only 31.9 months and the range was wide (2 to 155 months), so long-term outcomes remain uncertain.

Why it matters

For patients

If you are considering hip arthroscopy for impingement, this study suggests surgery may not protect against arthritis and could speed it up, so discuss expectations carefully with your surgeon.

For clinicians

These same-patient comparisons add to evidence that osteochondroplasty for FAI does not demonstrably prevent osteoarthritis and may accelerate degeneration, supporting cautious patient selection and counseling.

For readers

A clever within-patient design shows operated hips fared worse than their untreated twins, but its retrospective single-center nature means it raises a concern rather than settling the question.