How safe are minimally invasive photodynamic intramedullary implants?

At a Glance

Photodynamic intramedullary implants offer minimally invasive stabilization for impending and pathologic fractures but may carry underrecognized cardiopulmonary risks.
An 11.7% complication rate included implant failures, infection, severe hemodynamic instability, and three postoperative deaths.
Surgeons should carefully counsel patients with metastatic disease and consider procedural staging to mitigate perioperative risk.

Estimated read time: 4 minutes

Orthopaedic surgeons are increasingly turning to photodynamic nail implants as a minimally invasive option for stabilizing impending or pathologic fractures, especially in osteoporotic or metastatic bone. These systems use an uninflated balloon catheter inserted into the medullary canal that is filled with a photosensitive liquid polymer, which is then hardened with an external blue light to create a custom-fit internal support. But as the indications for this technology rapidly expand, questions remain about whether its streamlined surgical approach may mask a more complex risk profile. In a new retrospective review, investigators set out to examine how often intraoperative and postoperative complications occur with these implants — an effort that could help recalibrate surgeon expectations and guide safer decision making as adoption grows. The researchers presented their findings at the AAOS Annual Meeting earlier this year in New Orleans.

“We felt it was important to highlight some of the potentially significant complications that can occur with this technique and implant,” said Russell N. Stitzlein, MD, FAAOS, one of the study authors. “We have several surgeons at our institution, [myself] included, who feel this implant has some excellent and unique applications and indications. [There are] a few of us who have a fair amount of experience with the device and have seen the typical reported complications; however, we also experienced two patients with very major, and previously unreported, cardiopulmonary complications that resulted in death. We wanted to find an avenue to present these scientifically and felt that looking at the overall safety was an impactful way to do so.”

This retrospective review evaluated all patients who received photodynamic nail implants at a tertiary care center between March 2022 and December 2024, with procedures performed by fellowship-trained musculoskeletal oncologists or traumatologists. Researchers collected demographic information, American Society of Anesthesiologists (ASA) Physical Status Classification System scores, and Charlson Comorbidity Index (CCI) values. The researchers reviewed surgical details such as indication, operative site, and any use of additional hardware.

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“The occurrence of intraoperative and postoperative complications was recorded as the primary outcome measure,” the researchers wrote, “as the aim of the study was to identify complications occurring in the perioperative period and not long-term outcomes. All patients, regardless of duration of postoperative follow-up, were included in the study. Given the novel and unique nature of this implant, problems related to the ‘learning curve’ and surgical technique of using this implant were not considered intraoperative complications.

“Anecdotally, these issues included broken guidewires during reaming or tearing of the Dacron balloon during insertion,” they added. “These intraoperative technical difficulties associated with instrumentation of the implant were often not recorded in the operative note and ultimately did not contribute to patient morbidity or impact patients’ surgical outcome. Therefore, these issues were not recorded or considered intraoperative complications.”

Statistical analyses included chi-square or Fisher’s exact tests, t-tests, and Mann-Whitney U tests when appropriate, with significance set at P < 0.05.

The study included 73 patients — 33 of them men with a mean age of 66.9 years — who underwent 77 photodynamic nail procedures, most commonly for impending or pathologic fractures (70.1%), with the humerus representing the predominant surgical site (64.9%). Patients had a mean CCI of 5.97, and 68.8% carried an ASA score of 3; more than half of the cases (55.8%) required additional hardware to augment fixation.

The overall complication rate was 11.7%, including implant failures, one symptomatic implant requiring revision, a single surgical site infection, a case of severe hemodynamic instability, and three postoperative deaths — two of which followed cardiopulmonary arrest immediately after monomer injection and implant inflation. Although older age trended toward lower complication rates, this was not statistically significant, and no demographic or surgical variables predicted complications. Notably, all four cases of severe perioperative morbidity or death occurred in patients undergoing stabilization of metastatic cancer-related impending or pathologic fractures.

The authors note these severe complications may be related to sudden increases in intramedullary pressure during implant inflation, potentially triggering embolic events like those seen with cemented fixation. Study limitations include its retrospective design, small and heterogeneous patient population, and limited statistical power, which restrict the ability to draw firm conclusions about risk predictors. As use of this minimally invasive implant expands, the findings underscore the importance of thorough preoperative counseling — particularly for patients with compromised cardiopulmonary reserve.

“This research is significant because it highlights that even though the surgery can often be done quickly and through an incision of around one centimeter, it carries with it potentially significant cardiopulmonary risk. It has changed our practice,” said Dr. Stitzlein. “We previously would perform this ‘minimally invasive’ procedure in addition to another procedure in a different bone (e.g., photodynamic nail stabilization of a humerus and open reduction and internal fixation or intramedullary nailing of a femur); however, understanding the cardiopulmonary stress induced by the photodynamic nail process, we now fully separate that procedure to try to mitigate overall risk.”

The authors of “How Safe Are Minimally Invasive Photodynamic Intramedullary Implants?” are Christen E. Chalmers, MD; Amanda N. Goldin, MD, FAAOS; and Russell N. Stitzlein, MD, FAAOS.

Theresa Witham is managing editor for AAOS Now.