{
  "abstract": "Purpose: To compare the efficacy and safety of the modified prone split-leg position versus the lithotomy position in retrograde intrarenal surgery (RIRS) for upper urinary tract calculi.\n\nMethods: We retrospectively analyzed 270 patients undergoing RIRS for upper urinary tract calculi (November 2024–March 2026): modified prone split-leg (n = 103) and lithotomy (n = 167). After 1:1 propensity score matching (84 per group), operative time, hospital stay, day-1 stone-free rate (KUB), fever, renal function, and inflammatory markers were compared; subgroup, multivariable regression, and interaction analyses were performed.\n\nResults: After matching, baseline characteristics were balanced. The immediate radiographic stone-free rate (SFR), assessed by KUB on postoperative day 1, was 94.05% vs. 85.71% (P = 0.073). Operative time was longer with the modified prone split-leg position (54.00 vs. 38.50 min, P < 0.001), as was hospital stay (P = 0.012); the fever rate was 1.19% in both groups. In the 10–20 mm subgroup, SFR was significantly higher in the modified prone split-leg group (95.12% vs. 78.05%, P = 0.023). The renal stone subgroup showed a numerically higher SFR (92.31% vs. 42.86%, P = 0.031) but was hypothesis-generating owing to the small sample size. No SFR difference was found for ureteral stones (P = 0.290), and renal function and inflammatory markers did not differ between groups. Multivariable regression showed that the lithotomy position was associated with a higher risk of residual stones (OR = 5.327, P = 0.013) and shorter operative time (B = −10.295, P = 0.009). Interaction analyses were not significant (P for interaction: stone size 0.999, BMI 0.946, stone location 0.059).\n\nConclusion: In the unadjusted analysis, the immediate radiographic SFR did not differ significantly between the two positions. After adjustment for residual confounders, the modified prone split-leg position was independently associated with a lower risk of residual stones. It was also associated with a higher SFR for 10–20 mm stones; however, the interaction was not significant, and this finding should be interpreted cautiously. In the renal stone subgroup, a numerically higher SFR was observed, but this hypothesis-generating finding requires validation in larger studies.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Urology, The Second Affiliated Hospital of Chongqing Medical University , ,",
    "Department of Urology, Chamdo People’s Hospital , , ,"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Hongfei Li"
    },
    {
      "affs": [
        1
      ],
      "name": "Chao Li"
    },
    {
      "affs": [
        0
      ],
      "name": "Jiahang Liu"
    },
    {
      "affs": [
        0
      ],
      "name": "Xudong Yang"
    },
    {
      "affs": [
        0
      ],
      "name": "Yanjun Lin"
    },
    {
      "affs": [
        0
      ],
      "name": "Shengjie Yu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/711h4sycfvkjx.bib",
  "cited_by": 0,
  "doi": "10.3389/fsurg.2026.1959157",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13727563/?tool=EBI",
  "id": "711h4sycfvkjx",
  "issns": [
    "2296-875X"
  ],
  "landing_url": "https://europepmc.org/article/PMC/PMC13727563",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Original Research"
    ],
    [
      "openalex",
      "2740|Kidney Stones and Urolithiasis Treatments"
    ]
  ],
  "openalex": "W7223064530",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13727563/pdf/?tool=EBI",
  "pmcid": "PMC13727563",
  "pmid": "42978632",
  "published": "2026-10-20",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/711h4sycfvkjx.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:20:45Z",
      "native_id": "PMC:PMC13727563",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13727563"
    },
    {
      "first_seen": "2026-11-06T12:23:25Z",
      "native_id": "PMC13727563",
      "source": "pmc",
      "url": "https://doi.org/10.3389/fsurg.2026.1959157"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "journal-openalex:2746|Spinal Fractures and Fixation Techniques",
      "subfield": "surgery"
    }
  ],
  "title": "Comparison of the efficacy between modified prone split-leg position and lithotomy position in retrograde intrarenal surgery for upper urinary tract calculi",
  "title_text": "Comparison of the efficacy between modified prone split-leg position and lithotomy position in retrograde intrarenal surgery for upper urinary tract calculi",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T12:20:43Z",
  "url": "https://research.draconitic.com/paper/711h4sycfvkjx",
  "venue": "Frontiers in surgery",
  "versions": []
}