Gas Gangrene Following Posterior Tibial Tendon Transfer of a 34-Year-Old Patient – a Case Report

Introduction

Gas gangrene is a potentially fatal infection, most often caused by the bacteria Clostridium species. It is typically an infection occurring in the setting of contaminated wounds and was frequently described during periods of war [1]. In today’s surgical world it occurs rarely, it is most often associated with open trauma or abdominal surgery [2,3]. Recently, a distinct group of spontaneously developed cases of gas gangrene associated with the subspecies Clostridium septicum is gaining recognition [4]. Symptoms of gas gangrene include severe pain, fever, soft tissue edema and later massive soft tissue necrosis with crepitus due to gas accumulation [5,6]. Although this complication can be readily diagnosed once late symptoms of necrosis and gas accumulation develop, it may have already reached a stage at which the patient’s limb or even life are critically threatened. Therefore, the fundamental problem of this clinical entity remains early diagnosis at a stage when the patient’s symptoms are nonspecific, and clinicians rarely consider it a culprit. This is made even more difficult by the relative absence of known risk factors, although several case reports have described immunosuppression, diabetes, malignancies or prolonged tissue ischemia as conditions associated with developing this complication [7–9]. This article describes a rare case of gas gangrene development following an elective surgical procedure, offers three possible mechanisms of gas gangrene development as well as a suggestion of possible prevention.

Description of the case

A 34-year-old otherwise healthy man was acutely admitted to our neurosurgical department on the 10^th of November 2017 with a right common fibular nerve lesion at the fibula head, after being attacked by a wild boar during a hunting trip. The patient underwent immediate surgical revision with antibiotic prophylaxis, which verified complete common fibular nerve disruption as well as partial tearing of the biceps femoris muscle. A direct end-to-end microsurgical nerve reconstruction as well as biceps tendon suture were performed. The patient was discharged the next day with a knee orthosis and a planned check-up at our out-patient clinic. Fifteen months after the initial procedure, the patient did not show any clinical or electrophysiological signs of nerve regeneration, despite intensive rehabilitation (Figure 1). After informing the patient of his options, the patient agreed to a posterior tibial tendon transfer to improve function as well as cosmesis of his foot drop. The patient was admitted on the 27^th of March 2019 for the corrective procedure, which was performed in local conduction anesthesia in bloodless fashion utilizing a surgical tourniquet. The entire procedure was 79 minutes long. Postoperatively, an orthopedic cast was applied, and the patient was transferred to our standard neurosurgical ward for observation. The immediate postoperative course was uneventful, after regional anesthesia wore off, the patients’ right leg was without a new functional deficit, acral perfusion was intact and the surgical wounds were clean and calm with minimal edema. The patient was discharged in the morning of the first postoperative day, with a planned check-up and local analgesics for postoperative pain. Later that day, the patient contacted the operating surgeon due to intensive pain of the operated limb and after consultation was readmitted to the standard patient ward. Clinical examination of the affected limb showed only minor edema with adequate acral perfusion. The patient was administered analgesics and an acute ultrasound was performed on the second postoperative day in order to rule out deep-vein thrombosis or a muscle hematoma. The ultrasound revealed a small hematoma along the calf muscles and because the patient’s pain did not respond to analgesic therapy, surgical evacuation was planned the same day. Immediately after skin incision sweet, foul odor filled the room. Further dissection revealed macerated muscle tissue with subtle signs of necrosis, subcutaneous air bubbles and a dark oozieng fluid within the muscle compartments (Figure 2). Cultures were obtained and a trauma surgeon was called immediately in order to perform incision decompression of the lower limb, due to suspected compartment syndrome. The patient was transferred to the intensive care unit and antibiotic therapy targeting anaerobic bacteria was initiated. The next morning (3^rd day after tendon transfer), a trauma surgeon inspected the affected limb and indicated revision surgery due to progression of edema, crepitus and reduced acral perfusion. The decompressive incisions were extended, all muscle compartments opened, necrectomies and multiple lavages performed. As all muscle compartments contained necrotic tissue, fulminant gas gangrene was suspected. The patient was again transferred to the intensive care unit with signs of incipient septic shock, antibiotic therapy was intensified to Piperacillin/Tazobactam, Clindamycin, Ciprofloxacin, Metronidazole, and hyperbaric oxygen therapy was initiated. The next day (4^th day after tendon transfer), the patient’s right limb was cold, pulseless, the skin was livid with delayed capillary return. CT angiography showed minimal perfusion of the right lower limb arteries distal to the knee and a third surgical procedure was indicated. Prior the procedure, the patient was informed that amputation may be the only way to limit spread of infection. Surgical examination of the right limb demonstrated extensive myonecrosis in all muscle compartments and complete thrombosis of the posterior tibial artery without any residual perfusion (Figure 3). After consulting a trauma surgeon, amputation of the limb in the upper calf region was performed (Figure 4). In the following days, the patient’s clinical condition stabilized with improvement of local and systemic inflammation. Bacterial cultures demonstrated the presence of Clostridium perfringens, thus verifying the primary clinical diagnosis of clostridial gas gangrene. On the 7^th day after the original tendon transfer, the patient underwent a final corrective procedure to reshape the limb stump (Figure 5), he was transferred to the standard neurosurgical unit and later the Department of Prosthetics, where he was fitted with a suitable lower leg prosthesis (Figure 6). He was followed up regularly at our outpatient clinic and to this day is fully mobile, capable of household and basic sport activities (Figure 7).

Discussion

Gas gangrene is a potentially fatal infection, most often caused by the bacteria Clostridium species. Causes of these severe infections can be divided into traumatic, postsurgical and spontaneous (non-traumatic and non-surgical) [1]. Traumatic gas gangrene is most often associated with contaminated open wounds and typically occurs several hours to several days following trauma [2]. Postsurgical gas gangrene occurs classically after abdominal surgery, although rare cases following orthopedic surgery are described in literature [3]. Spontaneous gas gangrene is the rarest of the three etiologies. It is mostly caused by the subspecies Clostridium septicum and is strongly associated with cases of immunosuppression or malignancies [4]. In our case, the patient firstly presented with an open wound injury caused by the tusks of a wild boar, which was contaminated with soil and debris. Fifteen months later he underwent an elective reconstructive surgical procedure in local conduction anesthesia and a bloodless field. It is impossible to retrospectively identify the specific cause of gas gangrene in our patient, however based on current literature, there are three main possibilities.

The first is iatrogenic inoculation of bacteria during injection of local anesthetics for conductive anesthesia. Gas gangrene following injections is a rare event, however several case reports of this complication have been published. Driscoll and Kurnutala have both published cases of gas gangrene occurring after intramuscular injections of adrenaline, analgesics and anabolic steroids respectively [10,11]. They suggest that possible pathogens are needle contamination or activation of silent infection due to local hypoperfusion. Finally, White et al. describe a case of clostridial necrotizing fasciitis specifically after a femoral nerve block [7]. However, in our opinion this pathogenesis is the least likely cause of gas gangrene in our case, because the above-mentioned case reports describe gas gangrene typically originating from the injection point. In our case, the conduction block was performed in the inguinal and gluteal region, proximal the primary site of infection in the calf.

The second possibility is iatrogenic inoculation of bacteria during the posterior tibial tendon transfer. Although surgical equipment undergoes strict sterilization protocols and rules of asepsis are always followed during surgery, there have been reported cases of gas gangrene following orthopedic procedures. Ying et al. performed a literature review of gas gangrene occurring in orthopedic cases in 2013 [12]. Of the 50 reviewed cases, only three patients developed gas gangrene after elective orthopedic surgery, the remaining cases were associated with simple or compound fractures. Of the three cases, one occurred after hip arthroplasty, one after arthroscopic knee surgery and the last after opponensplasty. The first two cases were caused by Clostridium septicum, a subspecies of clostridia which is commonly associated with spontaneous gas gangrene. The third case published by Lorea et al. occurred after an elective abductor digiti minimi transfer due to a traumatic median nerve lesion and was caused by Clostridium perfringens [13]. This case is perhaps most similar to ours, however the case report lacks information concerning patient comorbidities (immunosuppression, diabetes, malignancies) all of which are associated with gas gangrene occurrence [8]. Furthermore, the case report does not say whether a surgical tourniquet was used in order to achieve a bloodless field. Finally, Wang et al. recently published a case report of gas gangrene caused by Clostridium perfringens after implant removal from the tibia [14]. In this case, a surgical tourniquet was used and in the discussion the authors suggest that hypoxia and vascular damage caused by the tourniquet may have been a contributing factor resulting in gas gangrene. They also suggest immunosuppression of the patient and tight dressing of the surgical wound as possible risk factors for the genesis of gas gangrene.

Finally, the last possible pathogenesis is activation of latent clostridial spores within the original wound caused by the wild boar. Clostridial spores are extremely resistant life forms, which can survive decades within a stable environment and their activation can be brought on by changes in pressure, temperature, or most often tissue oxygen concentration [15]. Therefore, hypoxia caused by the surgical tourniquet could have activated these latent life-forms leading to their proliferation and resulting in gas gangrene. Although this is difficult to prove retrospectively, the use of a tourniquet is considered a risk factor in developing gas gangrene, as are open contaminated wounds [9,12]. In our case, we believe that this pathogenesis to be the most probable in causing gas gangrene of the patient, because the likely source of clostridial spores are the contaminated boar tusks. If this was the case, it would be, to the best of our knowledge, the first-time gas gangrene occurred via a contaminated wound, 15 months after the original trauma.

In conclusion, gas gangrene is a potentially lethal complication of reconstructive surgery. There are many possible mechanisms of developing clostridial myonecrosis, however we believe that in our specific case, the cause of this complication was initiated by the use of the surgical tourniquet, which created anaerobic conditions resulting in activation of latent clostridial spores in the patient’s original wound. Thus, we suggest caution in utilizing bloodless operating fields in elective cases with a history of open contaminated wounds, as iatrogenic hypoxia can potentially activate sporulent bacteria within the patient’s wound. This should be performed in addition to general surgical wound care such as antiseptic lavage, debridement, sterile dressing and only moderate dressing compression.

Role of the authors: Jan Lodin MD is the first author, who performed the majority of literature research and wrote the discussion and parts of the case description. Ivan Humhej MD, PhD is the operating surgeon of the patient, taking part in all surgeries and provided major editing of the case description. Jana Táborská MD is head of the Department of Prosthetics, taking part in the patient’s final surgery and rehabilitation with prosthesis. Furthermore, she recorded follow-up data used in the case description. Prof. Martin Sameš MD, PhD is head of the neurosurgical department and oversaw the entire case as well as performing constructive review of the article

Declarations: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

All procedures within this study were performed in accordance with the ethical standards of and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

The patient whose case is described, consented to publishing of medical facts of his case, as well as figures showing parts of his body in order to demonstrate specific moments of the case report.

Jan Lodin, MD

Department of Neurosurgery, J. E. Purkyne University, Masaryk Hospital

Rabasova 13

401 11 Ústí nad Labem, Czech Republic

e-mail: jan.lodin@kzcr.eu

Submitted: 10. 11. 2020

Accepted: 02. 01. 2021