Patients with pilon fractures have a high incidence of talar osteochondral lesions. In this study, patients will undergo ankle arthroscopy at the time of external fixation. The objective is to help determine the incidence of these lesions with pilon fractures and to see if these nano-arthroscopy results change the plan for definitive treatment.

Previous studies have demonstrated a high incidence of talus osteochondral lesions (OCLs) associated with rotational ankle fractures, with rates reported as high as 45%. Consequently, an increasing number of surgeons have employed ankle arthroscopy at the time of fixation to evaluate and manage potential OCLs.

To date, no studies have assessed the incidence of talus OCLs associated with high-energy tibial plafond (pilon) fractures. Ankle arthroscopy at the time of definitive fixation for pilon fractures is often contraindicated due to significant soft tissue swelling and the risk of wound complications. However, if concurrent OCLs could be identified at the time of temporizing external fixation using nano-arthroscopy, such findings could inform surgical planning, including modifications to approach, staging, or definitive management.

Patients will be identified through a treating relationship to the patient when they present for management of their injury. Written consent for the arthroscopy portion, photos, sample collection will be performed while they are in the hospital before surgery, or at the same time they are consented for surgery.

The goal of the study is to enroll 25 participants.

Study Procedures

1. Operative Phase Eligible patients will be identified and consented for external fixation and possible diagnostic ankle nano-arthroscopy. During the external fixation procedure, following frame placement, the Arthrex Nanoscope will be introduced into the tibiotalar joint to evaluate for osteochondral lesions. Lesions will be documented regarding presence (yes/no), location, and size.

2. Imaging Phase (with blinding) Postoperative computed tomography (CT) scans will be obtained as part of standard preoperative planning for definitive fixation. A blinded surgeon (unaware of arthroscopy findings) will review the CT scans to assess for possible OCLs. Comparison between CT and arthroscopic findings will determine the incremental diagnostic value of nano-arthroscopy.

3. Surgeon Decision-Making Analysis

   After 25 patients are evaluated, six fellowship-trained orthopedic trauma or foot & ankle surgeons will independently review patient histories, radiographs, and CTs to develop a preoperative plan. They will then be shown the same cases with knowledge of OCL findings to determine whether this information alters their management strategy. Possible management modifications include:

   • Open reduction internal fixation (ORIF) with microfracture
   • ORIF with graftnet or biocartilage treatment
   • ORIF with allograft plug
   • ORIF with staged bulk allograft talus
   • Acute tibiotalar fusion
   • Acute total ankle arthroplasty

4. Synovial Fluid analysis from fluid collected at time of arthroscopy.

5. Tracking of outcomes and complications through standard of care follow-up.

Potential Risks

1. Potential risks of arthroscopy (swelling, stiffness, pain, arthritis, infection, blood loss, damage to neurovascular structures or tendons, increased time under anesthesia, and increased swelling) and loss of confidentiality.

   a. No additional risks are perceived from the synovial fluid collection as the same site will be used to aspirate the fluid as the saline will be injected and camera will enter for the arthroscopy.

2. This will be reduced through using currently approved standard approved technique for ankle arthroscopy and synovial fluid aspiration. Secure storage of PHI will be performed to reduce risk of loss of confidentiality.

Potential benefits

1. Potential benefits include identifying significant osteochondral lesions that could lead to better preoperative planning and potential for less secondary procedures due to immediate fusion or arthroplasty instead of fixation. Along with potential to help with optimal management of pilon fractures around the country/world.

Data Safety and Monitoring Plan Subject safety will be ensured through standard of care procedures and monitoring by clinical and surgical staff. Standard of care (SOC) patient reported outcomes (PROs) are directly entered into Patient IQ by the participant. Patient IQ contains INPUT validations to ensure data integrity. A sequential 1-25 patient number will be assigned instead of personally identifiable information. There will be a subject enrollment log with corresponding medical record number (MRN)/identification (ID) number-key that only the investigator and study staff will retain to link the patient records to the study case report forms.

Results of the nano-arthroscopy will be placed in the patients electronic medical record (EMR) as a part of the procedure not to ensure data integrity.

Paper source documents will be stored in a locked cabinet/room with only approved staff having access. Electronic medical records (CERNER) will be the primary source document with all associated security; data transposed into Patient IQ using defined case report forms for clinical study. Patient IQ is a cloud-based Health Insurance Portability and Accountability Act (HIPAA) Compliant, Health Information Trust Alliance (HITRUST) Common Security Framework (CSF) Certified, 21 Code of Federal Regulations (CFR) Part 11 Compliant platform used to collect the standard of care patient reported outcomes and data containing built in INPUT validations to ensure data integrity.

The Principal Investigator (PI) will monitor the study for safety, with a focus on serious adverse events (SAEs) and unexpected complications related to the nano-arthroscopy. These events will be monitored as part of standard of care treatment as they occur. If the events meet the criteria for Institutional Review Board (IRB) reporting, they will be reported to the IRB within five days.

The research coordinators will monitor the study data. The staff member will ensure data integrity at three-month intervals during the study. The coordinators and other research staff associated with this study are responsible for reporting any breach of confidentiality. All issues will be reported to the PI as well as to the other departments that are necessary based on the event.

Inclusion Criteria:

• Age ≥ 18 years (skeletally mature) Tibial plafond fractures with impaction of the articular surface requiring external fixation for temporization AO/Orthopaedic Trauma Association (OTA) Fracture classification 43-C type fractures (excluding posterior pilon or supination-adduction type ankle fractures) Closed injury

Exclusion Criteria:

• Prior ankle surgery

  • Pre-existing ankle arthritis
  • Unstable polytrauma patients precluding safe temporization
  • Concomitant talus or calcaneus fractures identifiable on plain radiographs
  • Pregnant
  • Prisoner
  • Unable to Consent