Meermans (2014) — The use of the transverse acetabular ligament for determining the orientation of the components in total hip replacement: a randomised controlled trial.

The Use of the Transverse Acetabular Ligament for Determining the Orientation of the Components in Total Hip Replacement: a Randomised Controlled Trial.

·Bone Joint J·2014·33 citations·Hip & Knee

This RCT compares freehand acetabular component placement against placement guided by the transverse acetabular ligament (TAL) as an anatomic anteversion reference in 80 patients undergoing primary total hip replacement through a posterior approach. The primary outcome is the proportion of cups landing within the established safe zone for anteversion and inclination on postoperative pelvic radiographs.

Study Snapshot

Design

Single-center RCT

Blinding: Single-blind

Setting: Single center, Bergen Op Zoom, Netherlands

Funding: None

Objective

Whether TAL reference improves acetabular component anteversion vs. freehand in THR

Outcome(s)

Acetabular component anteversion within safe zone (5°–25°)

Subjects

80 primary OA THR patients (40 per group)

40Freehand cup placement aiming 20° anteversion via mechanical guide
40TAL-guided cup anteversion using anatomical landmark

Inclusion

Age 20–90 years
Primary osteoarthritis diagnosis

Exclusion

Previous hip surgery
Secondary OA (dysplasia, trauma, osteonecrosis, childhood disease)
Femoral neck fracture, infection, or tumour

Follow-up

Minimum 2 years (mean 35.6 months)

Statistics

Fisher's exact testStudent's t-testF-testKolmogorov-Smirnov test

Key Findings

TAL guidance achieved 0% anteversion outliers versus 22.5% freehand (p = 0.002) — every TAL-guided cup landed within the 5°–25° safe zone
Mean anteversion was lower with TAL (17°, range 5°–25°) than freehand (21°, range 2°–35°), and variance was significantly tighter (p = 0.004 and p = 0.008 respectively)
TAL did not improve inclination: 37.5% freehand vs. 20% TAL outside the 30°–50° safe zone — a non-significant difference (p = 0.14)
Overall combined safe zone failure: 47.5% freehand vs. 25% TAL (p = 0.02), driven entirely by the anteversion benefit
The TAL was identifiable in 100% of TAL-group patients; 72.5% were visible on routine exposure, requiring no additional dissection

Clinical Relevance

When placing an acetabular cup via the posterior approach, identifying and aligning parallel to the TAL is a reliable, navigation-free method to control anteversion — but you still need a separate strategy (mechanical guide, navigation, or surgeon judgment) to hit your inclination target, since the TAL gives no reliable information in that plane.

Supplemental

The Use of the Transverse Acetabular Ligament for Determining the Orientation of the Components in Total Hip Replacement: a Randomised Controlled Trial.

Meermans, Kats, et al.·Bone Joint J·2014·33 citations·Hip & Knee

The Use of the Transverse Acetabular Ligament for Determining the Orientation of the Components in Total Hip Replacement: a Randomised Controlled Trial.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles

The Use of the Transverse Acetabular Ligament for Determining the Orientation of the Components in Total Hip Replacement: a Randomised Controlled Trial.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles

The Use of the Transverse Acetabular Ligament for Determining the Orientation of the Components in Total Hip Replacement: a Randomised Controlled Trial.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles

The Use of the Transverse Acetabular Ligament for Determining the Orientation of the Components in Total Hip Replacement: a Randomised Controlled Trial.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles