SuperPATH Preserves the Quadratus Femoris — but Not One-Year Clinical Outcomes

Polish version · Research Updates, Literature and Evidence-Based Medicine

A randomized trial published online on 8 September 2026 found substantially less quadratus femoris damage on MRI after total hip arthroplasty performed through the SuperPATH approach than through a conventional posterolateral approach. At one year, however, this did not translate into superior pain or functional outcomes. The distinction matters: better preservation of soft tissue on imaging does not automatically mean a benefit that patients can feel.

Why is this study interesting?

Debate about whether a surgical approach is “minimally invasive” often centres on incision length, early postoperative pain or speed of mobilisation. The authors of this study in The Journal of Arthroplasty asked a more objective question: does SuperPATH actually preserve the muscles and tendons around the hip better when assessed by MRI 12 months after surgery?

The study is particularly useful because it places an anatomical endpoint alongside clinical outcomes. That allows the MRI difference to be judged against what ultimately matters to the patient.

Research question and methods

Patients undergoing primary unilateral total hip arthroplasty were randomized to a SuperPATH approach — a superior capsular route with percutaneous introduction of part of the instrumentation — or to a posterolateral approach. The primary endpoint was the difference in quadratus femoris fatty infiltration on MRI at 12 months.

The investigators also assessed atrophy and tendon continuity in other periarticular muscles, perioperative parameters, pain on a visual analogue scale and function using the Harris Hip Score. Eighty-two patients completed the full follow-up. The public abstract does not state how many patients were initially randomized or provide detailed information on the handling of missing data.

Key results

• At 12 months, there were no significant differences in fatty infiltration or atrophy of the piriformis, obturator internus or gluteus minimus.
• Marked quadratus femoris fatty infiltration was reported in 7.3% of patients after SuperPATH versus 85.4% after the posterolateral approach; the difference was statistically significant.
• SuperPATH was also associated with less quadratus femoris atrophy and more frequent preservation of tendon continuity: 100% versus 56.1%.
• SuperPATH used a smaller incision but was associated with a longer operation and greater blood loss.
• At one month, pain and functional scores favoured SuperPATH; by 12 months the groups no longer differed clinically.
• Two early dislocations occurred in the posterolateral group.

Clinical interpretation for an orthopaedic surgeon

The trial provides a strong signal that the choice of approach can substantially affect the condition of a specific muscle as seen on MRI. At the same time, it demonstrates the limited value of a surrogate endpoint when considered in isolation: despite a striking imaging difference, patients had similar pain and function at one year.

The better one-month results may matter for early recovery, but they do not show that SuperPATH produces a lasting functional advantage. The longer operating time and greater blood loss also illustrate why “minimally invasive” should not be interpreted as “better in every respect”.

The two dislocations in one group are clinically relevant events, but this sample is far too small to establish a safety advantage. The trial was not presented as being powered to compare uncommon complications reliably.

Limitations

• The primary endpoint was an imaging outcome rather than an outcome directly experienced by the patient.
• No clinical superiority was shown at one year, so the practical importance of the large MRI difference remains uncertain.
• The public abstract does not provide the full participant flow, details of blinding for MRI assessment or the assumptions used for statistical power.
• The study was conducted at a single hospital in China, limiting generalisability to other surgical teams and learning curves.
• Twelve months is too short to assess the persistence of muscle differences, late dislocations, revision risk or implant survival.
• The findings apply to the specific comparison of SuperPATH with a posterolateral approach, not to every tissue-sparing hip approach.

What could this change in practice — and what does it not prove?

The study supports more precise counselling about SuperPATH: there is evidence of better quadratus femoris preservation on MRI and a possible early recovery advantage. It does not justify describing SuperPATH as clinically superior at one year, nor does it support changing surgical technique independently of surgeon experience, patient anatomy and the wider perioperative pathway.

Source

Gan F, Zhang Q, Luo H, Li L, Zheng F, Lin X, Qin H. Magnetic Resonance Imaging Assessment of Muscle Damage After Postero-lateral Versus Supercapsular Percutaneously-Assisted Total Hip Approaches: A Randomized Controlled Trial. J Arthroplasty. Published online 8 September 2026. PMID: 42710744. DOI: 10.1016/j.arth.2026.08.056. PubMed record.

Content prepared by: Tomasz Poboży - orthopaedic surgeon.