TO Plate Fixation vs. External Fixator Comparison (HTO Plate vs. ExFix Study)

NCT07220434 | Not Yet Recruiting FDA Device

• 1 other identifier: HTOexfix1
• Study Type: interventional
• Target: 28
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to compare the efficacy, accuracy, and functional outcomes of two different surgical stabilization techniques for medial opening wedge high tibial osteotomy (HTO) in patients with varus deformity and medial compartment osteoarthritis. Patients will be prospectively randomized into two groups: Group 1 (Plate Fixation) will receive acute (single-stage) correction and stabilization with a medial HTO locking plate. Group 2 (HTO External Fixator) will receive stabilization using a self-adjusting HTO external fixator, followed by gradual correction (hemicallotasis/distraction) starting 7 days post-operatively. The study will evaluate radiological correction, functional improvement (using the Oxford Knee Score), and complication rates over a 12-month follow-up period.

Conditions

Medial Compartment Osteoarthritis; Genu Varum; Varus Deformity; High Tibial Osteotomy

Outcome Measures

Primary Outcomes (3)

• Change in Radiological Correction (Hip-Knee-Ankle Angle - HKA)

  ssessment of the mechanical axis on full-length weight-bearing radiographs (Measured in degrees).

  Baseline (Preoperative), 6 Weeks, 3 Months, 6 Months, and 12 Months Postoperative.

• Change in Functional Status (Oxford Knee Score - OKS)

  Patient-reported functional score assessing pain and knee function.

  Baseline (Preoperative), 6 Weeks, 3 Months, 6 Months, and 12 Months Postoperative.

• Change in Pain Intensity (Visual Analogue Scale - VAS)

  Patient-reported pain score from 0 (no pain) to 10 (intolerable pain).

  Baseline (Preoperative), 6 Weeks, 3 Months, 6 Months, and 12 Months Postoperative

Secondary Outcomes (5)

• Change in Femoro-Tibial Angle (FTA)

  Baseline (Preoperative) and 12 Months Postoperative.

• Change in Mechanical Axis Percentage (MA%)

  Baseline (Preoperative) and 12 Months Postoperative.

• Change in Posterior Tibial Slope (PTE)

  Baseline (Preoperative) and 12 Months Postoperative.

• Change in Patellar Height (Insall-Salvati Index)

  Baseline (Preoperative) and 12 Months Postoperative.

• Incidence of Complications

  Up to 12 months postoperative.

Study Arms (2)

Group 1: Plate Fixation

EXPERIMENTAL

The osteotomy will be acutely corrected intraoperatively and stabilized using a Medial High Tibial locking plate.

Device: Medial HTO Locking Plate

Group 2: HTO External Fixator

ACTIVE COMPARATOR

he osteotomy will be stabilized using a Self-Adjusting HTO External Fixator. Gradual distraction (hemicallotasis) will begin 7 days post-operatively at a rate of 1 mm per day to achieve correction.

Device: Self-Adjusting HTO External Fixator

Interventions

Medial HTO Locking Plate DEVICE

Medial Opening Wedge High Tibial Osteotomy.

Group 1: Plate Fixation

Self-Adjusting HTO External Fixator DEVICE

Medial Opening Wedge High Tibial Osteotomy.

Group 2: HTO External Fixator

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Varus malalignment associated with medial compartment degeneration/osteoarthritis.
• Indication for Medial Opening Wedge HTO. Aged 18 years or older. Willing to participate in the study and provide written informed consent.

You may not qualify if:

• Advanced-stage osteoarthritis (Indication for Total Knee Arthroplasty). Previous open knee surgery on the same extremity. Inability to comply with follow-up appointments. Significant comorbidities (e.g., uncontrolled diabetes, rheumatoid arthritis).

Sponsors & Collaborators

• Muhammed Cagatay Engin: lead

Study Sites (1)

Ataturk University, Department of Orthopedics and Traumatology

Erzurum, Erzurum, 25240, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Genu Varum

Condition Hierarchy (Ancestors)

Bone Diseases; Musculoskeletal Diseases

Central Study Contacts

ali afşar, md

CONTACT

+905374927543; afsarali1708@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: October 22, 2025
• First Posted: October 23, 2025
• Study Start: November 15, 2025
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: October 23, 2025

Record last verified: 2025-10

Locations

TU (1)