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For patients diagnosed with Periprosthetic Joint Infection

The APEX Clinical Study

The APEX clinical study is studying a rapid 7-day treatment for PJI of the hip or knee using VT-X7. Patients who qualify and decide to enroll in the study will be randomly assigned to treatment with either VT-X7 or standard two-stage exchange surgery. Patients have equal chances of receiving VT-X7 or standard treatment but will not be told which treatment they received until they awake from the first surgery. 

What is PJI?

Periprosthetic joint infection (PJI) is a rare but serious complication after joint replacement surgery. PJI occurs when bacteria grow around your artificial joint, causing pain and swelling. Typically, these infections occur within five years of joint replacement surgery but can happen at any time. If left untreated, PJI can lead to amputation of the infected limb or even death. 
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What is Standard Treatment for PJI?

Your doctor may have recommended two-stage exchange arthroplasty (surgery) to treat your PJI. This involves removing the infected artificial hip or knee (stage 1), treating the infected tissue and bone with antibiotics, and implanting a new artificial joint (stage 2). Eliminating the infection requires intravenous (IV) antibiotics and placement of a temporary spacer that slowly releases antibiotics. After confirming the infection is gone, the surgeon will implant a new artificial joint. The total treatment time is typically about 16 weeks.

Standard Two-Stage Surgery

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Stage 1: Remove Infected Implant

  • Surgery to remove the infected implant
  • Insert temporary spacer containing antibiotic powder

Standard Treatment  

  • Intravenous antibiotics for at least 6 weeks
  • Surgeon watches for ongoing infection

Stage 2: New Permanent Implant

  • Surgery to remove the spacer and implant a permanent joint replacement

Rapid Two-Stage Surgery

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Stage 1: Remove Infected Implant

  • Surgery to remove the infected implant
  • Insert a VT-X7 titanium spacer

VT-X7 Treatment 

  • Antibiotics irrigated through the infected joint space for 7 days

Stage 2: New Permanent Implant

  • Surgery to remove VT-X7 spacer and implant a permanent joint replacement

What is VT-X7?

VT-X7 is a drug-device combination that delivers high concentrations of vancomycin and tobramycin, well-established antibiotic drugs, directly to the infected joint space.  When used as part of a two-stage exchange arthroplasty procedure, VT-X7 has the potential to significantly lower treatment time and improve success rates.
VT-X7 is an investigational product. Limited by federal law to investigational use.
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How does it work?

VT-X7 works by directly delivering antibiotics to the site of infection which means the bacteria infecting the joint are exposed to higher sustained concentrations.

Flushes the Joint Space
with Antibiotics

150+ Times
in 7 Days

Expected Advantages of VT-X7

  • Antibiotic concentrations at the infection site sufficient to penetrate biofilm
  • Effective against gram-negative and gram-positive organisms
  • Low antibiotic serum concentrations
  • Infection is treated and patient receives new revision prothesis in 7 days
  • Durable results: >90% of patients are infection free at 1 year post treatment

Is APEX right for you?

Talk to your doctor about enrolling in the APEX clinical study if you say YES to the following statements:​
  • I have been diagnosed with periprosthetic joint infection (PJI).
  • I have been told I need two stage exchange surgery. 

Can I choose VT-X7?

VT-X7 is an investigational product limited by US law to investigational use only. It is not available for sale and cannot be offered outside of the APEX study. 

Successful Phase 2 Results

Osteal Therapeutics conducted a Phase 2 prospective, single-arm, clinical trial for the treatment of patients with infected hip and knee prostheses at 4 U.S. centers. In the trial all subjects received new revision joint prostheses after 7 days of therapy and a clinically and statistically significant percentage of subjects were infection free at 12 weeks and 1 year.


Harbor-UCLA Medical Center

Torrance, California

United States, 90502

Principal Investigator:

Lewis Moss, MD

Research Coordinator:

Elaine Santana

Find a location


University of Utah

Salt Lake City, Utah

United States, 84108

Principal Investigator:

Jeremy Gililland, MD

Research Coordinator:

Shanna Loughmiller


Covenant Medical Center

Saginaw, Michigan

United States, 48602

Principal Investigator:

Brian De Beaubien, MD 

Research Coordinator:

Melanie Akin


Rothman Orthopaedic Institute

Philadelphia, Pennsylvania,
United States, 19107

Principal Investigator:

Max Courtney, MD

Research Coordinator: 

Alicia Reyes



University of Arizona, Phoenix

Phoenix, Arizona
United States, 85004

Principal Investigator:

J. Brock Walker, MD

Research Coordinator:

Marleny Munoz

University of Kentucky

Lexington, Kentucky

United States, 40506

Principal Investigator: 

Stephen Duncan, MD

Research Coordinator:

Lindsey Ball


Cleveland Clinic

Cleveland, Ohio,

United States, 44195

Principal Investigator: 

Nicolas Piuzzi, MD

Research Coordinator:

PJ Rullan


Ohio State University

Columbus, Ohio,

United States, 43202

Principal Investigator: 

Andrew Glassman, MD

Research Coordinator:

Nikhil Punwani


Texas Health Presbytarian - Plano

Plano, Texas

United States, 75093

Principal Investigator:

Kwame Ennin, MD

Research Coordinator:

Shuvalaxmi Dasgupta


Integris Southwest Medical Center

Oklahoma City, Oklahoma,
United States, 73103

Principal Investigator:

Bradley Reddick  


Stephanie Plummer


Columbia University

New York, New York

United States, 10032

Principal Investigator:

John Cooper, MD

Research Coordinator:

Jacquelynne Lenahan



UVA Orthopedics Center

Charlottesville, Virginia,
United States, 22903

Principal Investigator:

Ian Duensing, MD


Research Coordinator:
Eric McVey


OrthoCarolina Research Institute, Inc

Charlotte, North Carolina

United States, 28207

Principal Investigator: 

Bryan Springer, MD

Research Coordinator:

Taylor Rowe


Cleveland Clinic - Weston

Weston, Florida

United States, 33331

Principal Investigator: 

Carlos Higuera-Rueda, MD

Research Coordinator:

Jesus Villa, MD

University of Florida Health

Gainesville, Florida

United States, 32611

Principal Investigator: 

Hari Parvataneni, MD

Research Coordinator:

Emilie Miley


Sponsors and Collaborators

Osteal Therapeutics®
Osteal Therapeutics® is a privately-held, clinical-stage pharmaceutical company developing novel musculoskeletal therapeutics to treat orthopedic infections and their consequences.
Osteal Therapeutics employs a low risk development strategy by improving delivery of pharmaceuticals with long histories of safety and efficacy.
The company is lead by a highly experienced team of orthopedic industry veterans supported by world-class clinical partners.
Learn More
For more information about ongoing clinical study of VT-X7, visit
Protocol JPS-0301