Evidence map›Paper›PMID 40140896›Full record

Trial reportJournal of orthopaedic surgery and research2025

Cup positioning relative to the acetabular rim planned with three-dimensional computed tomography improves precision in total hip arthroplasty: a randomized controlled trial.

Anuwat Pongkunakorn, Napon Wongkamthong, Rukthanin Ruktrakul

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in Journal of orthopaedic surgery and research, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Anuwat PongkunakornDepartment of Orthopaedic Surgery, Lampang Hospital and Medical Education Center, 280 Paholyothin Road, Mueang District, Lampang, 52000, Thailand. dranuwat@hotmail.com.
Napon WongkamthongDepartment of Orthopaedic Surgery, Lampang Hospital and Medical Education Center, 280 Paholyothin Road, Mueang District, Lampang, 52000, Thailand.
Rukthanin RuktrakulDepartment of Orthopaedic Surgery, Lampang Hospital and Medical Education Center, 280 Paholyothin Road, Mueang District, Lampang, 52000, Thailand.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAccurate acetabular cup positioning is essential for successful total hip arthroplasty (THA) outcomes. The conventional mechanical alignment guide (MAG) method provides moderate accuracy. We developed a novel technique for cup positioning that utilizes preoperative three-dimensional computed tomography (3D-CT) planning based on the native acetabular rim's relative position and compared cup orientation between this method and the MAG technique.

methodsA randomized controlled trial with 120 patients undergoing primary THA via the posterolateral approach targeted cup positions of 40° radiographic inclination (RI) and 20° radiographic anteversion (RA). The control group (n = 40) used a MAG for cup placement, while the study group (n = 80) utilized preoperative 3D-CT to measure native RI, calculate RA, and determine the cup overhang distance (COD). The cup inclination was positioned relative to the superior rim point and the transverse acetabular notch. The cup anteversion was adjusted to achieve overhang at the posterior or anterior rim point according to the planned COD. Postoperative RI and RA were assessed using tilt-adjusted plain radiographs and CT scans. The percentages of cups positioned within 5° of the target position (RI/RA of 40°/20° ± 5°), and within the Grammatopoulos aiming zone (RI/RA of 40°/20° ± 10°) were compared between the two groups.

resultsThe mean RI was 41.7° ± 5.4° (range, 33°-59°) in the control group and 39.9° ± 3.2° (range, 33.8°-45.5°) in the study group (p = 0.019). The mean RA was 19.5° ± 7.6° (range, 3°-33°) in the control group and 20.2° ± 3.3° (range, 12.9°-28.3°) in the study group (p = 0.356). Cup alignment within 5° of the target was achieved in 86.2% (69 hips) of the study group and 32.5% (13 hips) of the control group (p < 0.001). The study group had a significantly higher percentage of cups within Grammatopoulos aiming zone (100% vs. 77.5%, p < 0.001).

conclusions3D-CT-guided cup positioning relative to the acetabular rim can enhance the precision of cup placement in THA to achieve alignment within 5° of the target position.

trial registrationThai Clinical Trials Registry (TCTR 20201220001). Registered on 20 December 2020. Prospectively registered.

Indexed as

AcetabulumArthroplasty, Replacement, HipHip ProsthesisImaging, Three-DimensionalTomography, X-Ray ComputedAdultAgedFemaleHumansMaleMiddle Aged3D-CTAcetabular cup positioningRandomized controlled trialTotal hip arthroplasty

Identifiers

PMID40140896
PMCPMC11948801

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.