Efficiency and Safety of Navigation Aids in Total Hip Arthroplasty With Direct Anterior Approach

China Medical University

Status: Completed

Conditions: Osteoarthritis, Hip; Developmental Dysplasia of the Hip; Femur Head Necrosis

Treatments: Procedure: Conventional total hip arthroplasty; Device: Navigation system

Study type: Interventional

Funder types: Other

Identifiers

NCT07134036

CMUH112-REC1-149

Details and patient eligibility

About

This prospective clinical study aimed to evaluate the effectiveness of an imageless navigation system in total hip arthroplasty (THA) via the direct anterior approach (DAA) on a traction table for reducing functional limb length discrepancy (LLD) compared with conventional techniques. Seventy-two patients with advanced hip osteoarthritis, avascular necrosis, or developmental dysplasia of the hip undergoing THA between March 1, 2021 and September 30, 2021 were included. Functional LLD was assessed using a preoperative block test. Participants were assigned to the navigation or conventional group based on patient preference. Outcomes included operative parameters, intraoperative fluoroscopy time, limb length measurements, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores.

Full description

This single-center prospective comparative study was conducted at the Joint Reconstruction Center of China Medical University Hospital between March 1, 2021 and September 30, 2021. Eligible participants were adults diagnosed with advanced hip osteoarthritis, avascular necrosis, or developmental dysplasia of the hip requiring THA. Exclusion criteria included prior hip joint infection, severe LLD requiring additional reconstructive procedures, significant spinal pathology affecting spinopelvic balance, or radiographs inadequate for measurement.

All procedures were performed via the direct anterior approach (DAA) on a traction table by the principal surgeon. Functional LLD was assessed preoperatively using a block test, with wooden blocks (5 mm increments) placed under the heel until the patient reported equal leg lengths.

Patients in the navigation group underwent THA with an imageless navigation system (Stryker OrthoMap Versatile Hip Navigation) to record intraoperative limb length change and acetabular cup positioning; the conventional group underwent standard THA without navigation.

Primary outcome was the patients' expectation gap (PEG), defined as the difference between preoperative functional LLD and postoperative radiographic limb length change. Secondary outcomes included intraoperative fluoroscopy time, WOMAC scores at baseline, 3 weeks, and 3 months postoperatively, and the proportion of outliers (PEG > 10 mm).

The study was approved by the Research Ethics Committee of China Medical University Hospital (CMUH112-REC1-149). Written informed consent was obtained from all participants, and the study adhered to the Declaration of Helsinki.

Enrollment: 72 patients

Sex: All

Ages: 20+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Clinical diagnosis of advanced hip osteoarthritis (OA) warranting total hip arthroplasty (THA)
• Clinical diagnosis of avascular necrosis (AVN) of the femoral head warranting total hip arthroplasty (THA)
• Clinical diagnosis of developmental dysplasia of the hip (DDH) warranting total hip arthroplasty (THA)

Exclusion criteria

• Documented history of prior hip joint infection
• Severe limb length discrepancy requiring supplementary surgical interventions
• Significant spinal pathology affecting spinopelvic balance
• Radiographs in which the lesser trochanters and teardrops cannot be clearly defined

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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72 participants in 2 patient groups

Conventional THA

Active Comparator group

Description:

Participants in this group underwent total hip arthroplasty (THA) via the direct anterior approach on a traction table without the use of a computer navigation system. This arm represents the conventional surgical technique routinely performed at our institution, where intraoperative limb length assessment was based on standard fluoroscopic guidance and anatomical landmarks.

Treatment:

Procedure: Conventional total hip arthroplasty

Navigation-assisted THA

Experimental group

Description:

Participants in this group underwent total hip arthroplasty (THA) via the direct anterior approach on a traction table with the assistance of an imageless computer navigation system (Stryker OrthoMap Versatile Hip Navigation). The navigation system provided real-time intraoperative feedback on limb length change and acetabular cup positioning, aiming to improve accuracy and reduce reliance on fluoroscopy.

Treatment:

Device: Navigation system