This is a pivotal, prospective, multi-center, randomized, concurrent control, patient and assessor-blinded study with two arms: a treatment arm (where subjects will be treated with the EP Granules with Tobramycin investigational device in the 1st stage of a staged revision for periprosthetic joint infection (PJIs), and a control arm (where subjects are treated with the standard-of-care revision for infected PJIs).

This is a pivotal, prospective, multi-center, randomized, concurrent control, patient and assessor-blinded study to demonstrate superiority of new bone growth and a reduction in recurring infections, and thereby improve outcomes for patients undergoing a staged revision for periprosthetic joint infections (PJIs).

The standard of care for treatment of PJIs typically involves either a 2-stage revision or 1.5 stage revision which entails loss of bone stock resulting from debridement of infected bone in Stage 1. In the Stage 2 procedure, surgeons use metal cones to make up for this bone loss and better support the revision implant. Inadequate bone growth could result in gaps at the the voids below the level of the cortical bone, resulting in regions with no contact with the revision implant or cement mantle. Such gaps could result in dead-space regions, and zones without new bone growth required to support the revision implant. Both deficiencies affect long-term survival of the revision implant.

The study has two arms: a treatment arm (where subjects will be treated with the EP Granules with Tobramycin investigational device in the 1st stage of the staged surgical treatment, and a control arm where subjects are treated with the standard-of-care staged surgical treatment for infected PJIs.

Outcomes are demonstration of new bone growth and reduction of recurrent infections.

Inclusion Criteria:

• Ages and sexes eligible: at least 22 years, male and female
• Candidates with known infected TKA
• Life expectancy of at least 1 year
• Patient is willing to provide informed consent, is geographically stable and able to comply with the required follow up visits, testing schedule and medication regimen
• Adequate soft tissue coverage
• Signed institutional review board approved informed consent

Exclusion Criteria:

• Severe renal impairment with eGFR <50 ml/min/1.73 m2, or being treated with dialysis

  • Known hypersensitivity to aminoglycoside antibiotics, or calcium hydroxyapatite
  • Pre-existing calcium metabolism disorder
  • Uncontrolled diabetes mellitus (hemoglobin A1c levels > 8)
  • A current endocrine or metabolic disorder known to affect osteogenesis (e.g., Paget's disease, renal osteodystrophy, hyperthyroid parathyroid hormone disorder, Ehler- Danlos syndrome, osteogenesis imperfecta)
  • Neuromuscular disorders such as myasthenia gravis
  • Untreated malignant neoplasm(s), or currently undergoing radiation chemotherapy
  • Inadequate neurovascular status in the involved limb that may jeopardize healing
  • HIV
  • Pregnancy
  • Adult patients requiring a legal guardian to sign informed consent form