Robotic Arm-assisted THA Vs. Conventional THA in Legg-Calvé-Perthes Disease

Comparison of Robotic Arm-assisted THA and Conventional Manual THA in Patients With Legg-Calvé-Perthes Disease: a Prospective Cohort Study

Flat hip, also called Legg-Calvé-Perthes disease, is clinically characterized by flattened femoral head, shortened femoral neck, and a center of rotation of the femoral head lower than the apex of the greater trochanter. Joint replacement is difficult, with high intraoperative and postoperative complications. Especially, issues such as unequal limb length, postoperative dislocation, postoperative neurological damage, and prosthesis impact have always plagued clinical practice.

The robotic arm-assisted joint replacement technology has been developed and clinically applied for over 10 years, but it was not until the past 3 years that it began to be widely implemented worldwide. Existing research data indicates that robotic arm-assisted joint replacement technology can significantly improve the placement of prostheses and lower limb force lines in patients, and improve their short-term clinical prognosis. However, its application in complex hips, such as flat hip, is limited. More relevant literature is needed to further enrich people's understanding of this technology. In theory, robot assisted technology can solve many challenges faced in flat hip replacement.

Study Overview

• Status: Enrolling by invitation
• Conditions: Legg-Calvé-Perthes Disease
• Intervention / Treatment: Procedure: conventional total hip replacement; Procedure: robotic arm-assisted total hip replacement

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310009
      • Second Affiliated Hospital of Zhejiang University School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• patients with Legg-Calvé-Perthes disease and accept total hip replacement in our center

Exclusion Criteria:

• infection, cannot complete follow-up

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: conventional total hip replacement; applying conventional total hip replacement in patients with Legg-Calvé-Perthes disease	Procedure: conventional total hip replacement; applying conventional total hip replacement in patients with Legg-Calvé-Perthes disease
Experimental: robotic arm-assisted total hip replacement; applying robotic arm-assisted total hip replacement in patients with Legg-Calvé-Perthes disease	Procedure: robotic arm-assisted total hip replacement; using robotic total hip replacement in patients with Legg-Calvé-Perthes disease

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
inclination angle	The inclination angle in total hip replacement (THR), also called the abduction angle , refers to the angle at which the acetabular cup component is tilted relative to the horizontal plane when viewed on an anteroposterior (AP) pelvic X-ray.	2 days after surgery
anteversion angle	The anteversion angle in total hip replacement (THR) refers to the forward tilt (rotation) of the acetabular cup component around its vertical axis. It determines whether the cup's opening faces more forward or backward relative to the pelvis.	2 days after surgery
Hospital for Special Surgery Score score (HSS score)	The maximum values is 100, and the minimum value is 0. Higher scores means a better outcome.	before the surgery, 1 week after surgery, 1 month after surgery, 6 months after surgery, 1 year after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
operation duration	The operation duration (also called operative time or surgical time ) refers to the total time taken to complete a surgical procedure.	during the operation
blood loss	The amount of blood loss during the surgery.	during the operation
Visual Analogue Scale score (VAS score)	The maximum value is 10, and the minimum value is 0. Lower score means a better outcome.	before the surgery, 1 week after surgery, 1 month after surgery, 6 months after surgery, 1 year after surgery

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

Study Major Dates

• Study Start (Actual): July 28, 2025
• Primary Completion (Estimated): July 28, 2027
• Study Completion (Estimated): July 28, 2027

Study Registration Dates

• First Submitted: August 7, 2025
• First Submitted That Met QC Criteria: August 13, 2025
• First Posted (Actual): August 14, 2025

Study Record Updates

• Last Update Posted (Actual): August 14, 2025
• Last Update Submitted That Met QC Criteria: August 13, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: MAKO; Legg-Calvé-Perthes disease; flat hip
• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Femur Head Necrosis; Osteonecrosis; Legg-Calve-Perthes Disease
• Other Study ID Numbers: 2025-1100

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No