Gait After THA: Direct Anterior vs Manual Posterior vs Robotic Posterior

Ochsner Health System

Status: Enrolling

Conditions: Osteoarthritis (OA) of the Hip

Treatments: Procedure: Total hip arthroplasty via posterior approach (manual, non-robotic); Procedure: Robotic-assisted total hip arthroplasty via posterior approach; Procedure: Total hip arthroplasty via direct anterior approach (manual, non-robotic)

Study type: Interventional

Funder types: Other

Identifiers

NCT07226973

2025.027

Details and patient eligibility

About

The purpose of this study is to evaluate the gait biomechanics following THA on 3 groups of subjects undergoing DAA (manual) and PA (manual and robotic) surgical approaches.

Full description

Single-center, three-arm, partially randomized interventional study comparing gait biomechanics after primary total hip arthroplasty (THA) via (1) manual direct anterior approach (DAA), (2) manual posterior approach (PA), and (3) robotic-assisted posterior approach (rPA). One surgeon's patients are randomized to DAA vs PA; the second surgeon's patients receive rPA per routine practice. Outcomes assessors are blinded (motion-capture suit conceals dressings/scars). Gait and sit-to-stand analyses are performed pre-op and at 6 and 12 weeks post-op using a Vicon motion capture system with force plates and surface EMG. Patient-reported outcomes are collected with standard instruments. The trial evaluates short-term biomechanical recovery and patient-reported outcomes across approaches.

Enrollment: 48 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adults aged >18 undergoing primary elective THA for osteoarthritis
• BMI <35
• Ability to walk unassisted (cane, walker, wheelchair, ect) for > 150 feet preoperatively

Exclusion criteria

• Previous hip surgery on the affected side
• Neurological disorders affecting gait
• Contraindication to either DAA or PA

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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48 participants in 3 patient groups

Manual Direct Anterior Approach (DAA)

Active Comparator group

Description:

The DAA utilizes an internervous and intermuscular approach, preserving abductor and posterior soft tissues, and is associated with reduced dislocation rates and accelerated early recovery.⁶ However, it carries a steep learning curve and an elevated risk of lateral femoral cutaneous nerve neuropraxia.

Treatment:

Procedure: Total hip arthroplasty via direct anterior approach (manual, non-robotic)

Manual Posterior Approach

Active Comparator group

Description:

PA remains the most commonly used technique worldwide, offering extensile exposure and preserved abductor function, though its historical association with increased dislocation risk has necessitated meticulous capsular and soft-tissue repair.

Treatment:

Procedure: Total hip arthroplasty via posterior approach (manual, non-robotic)

Robotic-Assisted Posterior Approach

Active Comparator group

Description:

Robotic-assisted THA introduces computer-navigated precision into implant alignment and biomechanical restoration. Contemporary systems (e.g., MAKO) offer intraoperative haptic guidance and preoperative CT-based planning to improve component placement accuracy.

Treatment:

Procedure: Robotic-assisted total hip arthroplasty via posterior approach