Implant Salvage in Patients With Severe Post-Fracture Fixation Surgical Site Infection Using Negative Pressure Wound Therapy With Intramedullary and Subcutaneous Antibiotic Perfusion

Surgical site infection (SSI) after fracture fixation is associated with higher-grade Gustilo-Anderson open fractures (ie, type III).^1,2 Patients with SSI that has progressed to deep infection or osteomyelitis must undergo multiple surgeries and may experience permanent dysfunction at the fracture site. Radical surgical debridement, orthopedic implant removal, and systemic antibiotic administration are generally performed to control SSIs. Orthopedic implant removal is considered to be an efficacious procedure. For example, 28% to 79% of orthopedic implants are removed after foot, ankle, or lower leg fracture surgery.^3,4 After orthopedic implant removal, postoperative SSI rates are reportedly 0% to 20%.^3-5 The standard-of-care therapeutic regimen is insufficient in the management of SSI after fracture fixation. Some studies have reported the use of negative pressure wound therapy with instillation and dwell time (NPWTi-d) to treat patients with infected orthopedic fixation hardware.^6-9 Although NPWTi-d is thought to be effective in managing superficial SSI after fracture fixation, it may not be therapeutically effective for deep SSI, due to the difficulty of disrupting the biofilm in the deep dead space.⁷

Recently, Himeno et al¹⁰ reported a method for managing limb infection that involves continuous local antibiotic perfusion in conjunction with NPWT. In that study, intramedullary and subcutaneous antibiotic perfusion were applied to manage bone and soft tissue infections, respectively. The authors of this report hypothesized that such antibiotic perfusions could be applied to manage post-fracture fixation SSI with a dead space that would predispose a patient to bone infection. The authors of this case report modified and applied this technique to treat patients with severe SSI after below-knee fracture fixation, with the goal of salvaging the orthopedic implant. The modified technique is described herein.

The use of NPWT with intramedullary and subcutaneous antibiotic perfusion is a 2-stage procedure that consists of surgical debridement and flap reconstruction. Written informed consent was obtained from both patients presented in this report.

Surgical debridement

The previous skin incision is reopened and, if necessary, the incision is enlarged to expose the infected site. Infected tissues are debrided to preserve the orthopedic implant, and the wound is irrigated with copious saline. A double-lumen tube (16 Fr Salem Sump Silicone Tubes; Cardinal Health) is placed as deep as possible into the wound, near the implant. A 2.4-mm Kirschner wire is used to create a hole in the cortical bone along the implant fixation area, after which 2 bone marrow needles (Tohoku University bone marrow puncture needle; Senko Medical Instrument Manufacturing Co. Ltd.) are inserted. Antibiotics should be selected in accordance with the results of bacterial culture. For instance, gentamicin solution (50 mL total [60 mg of gentamicin per milliliter of 0.9% saline solution]) is continuously administered at a rate of 2 mL per hour through the bone marrow needles and double-lumen tubes as intramedullary and subcutaneous perfusions, respectively. A black foam sponge is placed within the wound and then connected to an NPWT device (RENASYS TOUCH; Smith + Nephew) through a Y-connector, in conjunction with the double-lumen tube (Figure 1A). Continuous negative pressure is set at −80 mm Hg.

The aforementioned procedure is similar to that described by Himeno et al.¹⁰ The black foam sponge and double-lumen tube are replaced after approximately 5 days. The patient undergoes NPWT with intramedullary and subcutaneous antibiotic perfusion for approximately 1 to 2 weeks, until granulation tissue forms in the wound and inflammation subsides, as confirmed with a blood test (eg, C-reactive protein level).

Flap reconstruction

After wound debridement, a free musculocutaneous or fasciocutaneous flap is transferred to the wound. After microvascular anastomosis is performed, the double-lumen tube is placed under the flap and the bone marrow needles are inserted into the bone marrow. The black foam sponge is placed along the edges of the flap and connected to the NPWT device through the Y-connector, in conjunction with the other double-lumen tube (Figure 1B). The double-lumen tube and bone marrow needles are removed approximately 5 days postoperatively.

Cases

The authors of this case report applied surgical debridement and flap reconstruction followed by NPWTi-d to 2 patients with abscess collections due to SSI after either tibial or calcaneal open fracture fixation using titanium plates. The infected wound of the lower leg involved a deep dead space that reached the crural interosseous membrane, whereas the heel wound was accompanied by a subcutaneous pocket. The debrided wounds of the lower leg and heel were reconstructed with free latissimus dorsi musculocutaneous and anterolateral thigh fasciocutaneous flaps, respectively, to preserve the titanium plates. In both patients, the wounds healed without complications and remained healed after more than 7 months following treatment. Figures 2, 3, and 4 show photographs of the lower leg wound in a 59-year-old male before and after treatment.

Surgical site infection after fracture fixation is a devastating complication, and infection control may require orthopedic implant removal or replacement. However, for patients with deep SSI, whose orthopedic implants are difficult to remove, preservation of the orthopedic implant is warranted. Negative pressure wound therapy with instillation and dwell time is recommended as an adjunct therapy in patients with infected or contaminated wounds involving orthopedic fixation hardware.¹¹ Some studies have reported that NPWTi-d with various types of instillation fluids can be used to salvage infected orthopedic fixation hardware.^6-9 However, Hehr et al⁶ reported that original lower extremity hardware was salvaged in only 33% of patients after fracture fixation, which shows the difficulty of using NPWTi-d. Several methods reportedly involve local delivery of antibiotics to control orthopedic infections. The use of antibiotic-impregnated cement and beads,¹² antibacterial powder sprays,¹³ and local antibiotic injections¹⁴ in the management of orthopedic infections is long established. These methods are disadvantageous because antibiotic concentrations decrease with time¹⁵; thus, it is better to use a method that maintains a constant antibiotic concentration.

Based on this finding, the 2 patients in this case report were treated using continuous intramedullary and subcutaneous antibiotic perfusion. That is, a double-lumen tube was used for subcutaneous antibiotic perfusion and dead space suction drainage, and bone marrow needles were used for intramedullary antibiotic perfusion.

Although the use of topical antiseptic or antibiotic perfusion is considered effective in the management of SSI, Kurlander et al¹⁶ reported the efficacy of a combination of sub-flap irrigation using normal saline and NPWT in the management of infected extremity wounds after flap reconstruction. After debridement, the use of intramedullary and subcutaneous antibiotic perfusion in the patients in the current report may have had a more notable therapeutic effect on the infected wounds in the presence of orthopedic fixation hardware. It is unknown, however, whether the antibiotic perfusion was necessary at all, let alone necessary for 5 days. Subcutaneous flap irrigation using normal saline may have been sufficient. Himeno et al¹⁰ used intramedullary antibiotic perfusion to manage osteomyelitis, but the efficacy of intramedullary antibiotic perfusion for post-fracture fixation SSI was not clarified in their study.

Although intramedullary antibiotic perfusion is effective in managing or preventing early osteomyelitis with seemingly few side effects, more work is required to clarify the procedure and its efficacy. In the 2 patients in this case report, intramedullary antibiotic perfusion apparently affected the bone and orthopedic implant (intramedullary nail and screw) infections. In both patients, the infections were successfully managed without the need for titanium plate removal.

The main limitation of this technique is that it has been tested in only 2 cases. Studies with adequate sample sizes of patients with abscess collection owing to SSIs after open fracture fixation are required to verify the efficacy of this technique.

Continuous local antibiotic perfusion around an infected orthopedic fixation device can be an ideal treatment for the patient with SSI after fracture fixation. The technique described herein may be effective in the setting of severe SSI after fracture fixation that includes dead space with a risk of bone infection. This technique can be improved, and further research is needed to compare the efficacy of this technique with that of conventional NPWTi-d and to better understand its applicability in surgical practice.