Hyperbaric Oxygen Therapy in the Management of Zygomatic Bone Osteomyelitis

Abstract

Introduction

Zygomatic bone osteomyelitis is a rare condition having an incidence of 1.42%. Zygomatic osteomyelitis can be due to haematogenous infection with tubercle bacillus, facial bone fractures or very rarely due to an unknown aetiology like in our case. If surgically managed alone, it would lead to complete loss of zygomatic bone, causing high morbidity to the patient in terms of function and aesthetics like loss of globe support causing dystopia, loss of facial projection causing facial asymmetry. Restoration of facial symmetry and globe support would require extensive procedures such as non-vascular bone grafting or patient-specific implant placement or microvascular bone flap transfer.

Materials and Methods

Hyperbaric oxygen therapy (HBOT) was used to try and preserve the zygoma by promoting revascularisation. The patient received 100% oxygen at 2.5 absolute atmospheric pressure for 90 min, one session per day for 5 days in a week using a mask system in a multiplace chamber. The patient was reviewed clinically and radiologically after each 5 dives of HBOT sessions. After a total of 30 dives of HBOT, CT examination was repeated. There was partial reconstitution of cortical bone without any additional residual bone lesion. Minimal residual sequestra were noted. At this stage, the patient underwent conservative sequestrectomy in contrast to extensive surgery if HBOT was not contemplated.

Conclusion

HBOT has the potential to be a very useful adjunct in the treatment of osteomyelitis in head and neck surgery; however, there is a need for carefully designed trials, avoiding methodological bias due to the great variability of patients, infectious agents, antibiotic resistance, host factors, to broaden the evidence of this therapeutic modality.

Introduction

Zygomatic bone osteomyelitis is a rare condition having an incidence of 1.42% [1]. Trauma and tuberculosis are the most common causes of zygoma osteomyelitis reported in the literature [2]. We present an unusual case of zygomatic bone osteomyelitis which was successfully treated by hyperbaric oxygen therapy (HBOT). Although adjunctive HBOT has been frequently used in the treatment of osteomyelitis of the jaws [3], this is the first reported case wherein HBOT is shown to be effective even in the case of Zygomatic bone involvement.

Case Description

A 55-year-old man reported to Craniofacial surgery department, Mazumdar Shaw Medical Hospital, Narayana Health with left malar swelling and discharging pus from the skin below left eye for 2 months (Fig. 1a). There was no history of trauma to face or any other clinical source of infection. Blood investigations revealed elevated blood sugar levels. Random blood sugar was 320 gm% and glycosylated haemoglobin level 9 gm%. Pus was sent for culture and sensitivity, and it did not show any growth or acid-fast bacilli on microscopy. Chest X-ray was normal and montoux test was negative; hence, pulmonary tuberculosis was ruled out. The patient was started on insulin therapy, facial swelling and pus discharge reduced with blood sugar control.

Fig. 1.

a Arrow mark indicating pus discharge in the left infraorbital region. b Post 15 dives of HBOT, Arrow mark indicating; persistent fistulous tract with cessation of pus discharge. c 6 months follow-up, Arrow mark showing healed infraorbital skin without any residual deformity

Computed tomography (CT) of craniofacial region revealed, extensive osteolytic lesion involving the zygomatic bone with formation of sequestrum. CT findings were suggestive of chronic osteomyelitis of the zygomatic bone (Fig. 2a). Sequestrectomy or sauserization in this situation, if performed would have resulted in complete loss of the zygoma.

Fig. 2.

a Axial and coronal CT images (a) demonstrate extensive permeative, osteolytic lesions involving left zygoma with central sequestrum. b Axial and coronal CT follow-up images (b) after 30 dives of hyperbaric oxygen therapy show partial reconstitution of cortical bone with persistent residual minimal sequestrum. c Axial and coronal CT images at 6-month post-op follow-up (c), there is near complete reconstitution of bone structure and resorption of sequestrum

Along with aggressive diabetes control, HBOT was considered to try and preserve the zygoma by promoting revascularisation. The patient received 100% oxygen at 2.5 absolute atmospheric pressure for 90 min, one session per day for 5 days in a week using a mask system in a multiplace chamber. The patient was reviewed clinically and radiologically after each 5 dives of HBOT sessions. After 15 dives of HBOT, there was no more pus discharge from the left infraorbital fistula (Fig. 1b). The patient was advised to undergo an additional 15 dives of HBOT. After a total of 30 dives of HBOT, CT examination was repeated. There was partial reconstitution of cortical bone without any additional residual bone lesion. Minimal residual sequestra were noted (Fig. 2b).

At this stage, the patient underwent conservative sequestrectomy via intraoral maxillary vestibular incision under general anaesthesia. Through left subtarsal approach, the cutaneous fistula was traced its course down to the zygomatic bone and excised.

Histopathological sections of the excised specimen (Fig. 3) showed remodelling bone surrounded with inflammation and fibrosis. No granulomas were seen. No acid-fast bacilli were seen on Ziehl–Neelsen stain, and no Fungi seen on Periodic acid Schiff stain. These findings were consistent with chronic osteomyelitis.

Fig. 3.

Histopathological sections of the excised specimen showing remodelling bone surrounded with inflammation and fibrosis (haematoxylin and eosin, × 2.5)

Post-operative healing was uneventful. The patient received another 10 dives of HBOT. At six month follow-up, the patient was symptom free (Fig. 1c) and CT face revealed complete reconstitution of the zygomatic bone, increased mineralisation of bone trabeculae (Fig. 2c).

Discussion

Zygomatic bone osteomyelitis is extremely rare owing to its high regional vascularity [4], low bone density and farther distance from the dental structures. Osteomyelitis of Zygoma can be due to haematogenous infection with tubercle bacillus, facial bone fractures [2] or, very rarely due to an unknown aetiology like in our case.

Diabetes mellitus (DM) is a well-documented predisposing systemic disease influencing the development and continuation of osteomyelitis in several ways [5]. In DM, there is defective glucose utilisation which leads to protein breakdown. The leukocytes have diminished chemotaxis, phagocytosis and reduced life span. These factors lead to delayed bone healing [4]. Diabetic micro- and macroangiopathy reduces tissue perfusion and hence the ability to mount an effective inflammatory response, and the delivery of antibiotics to the target area. All these factors reduce host resistance perpetuating infection [5].

In our case, the entire Zygomatic bone was involved with osteomyelitis. If surgically managed alone, it would lead to complete loss of Zygomatic bone. This would cause high morbidity to the patient in terms of function and aesthetics like loss of globe support causing dystopia, loss of facial projection causing facial asymmetry. Restoration of facial symmetry and globe support would require extensive procedures such as non-vascular bone grafting or patient specific implant placement or microvascular bone flap transfer.

Hyperbaric oxygen allows a better infection demarcation in chronic osteomyelitis. As a consequence, less major surgery seems to be required for infection control. Adjunctive HBOT improves outcomes and reduces the need for surgical re-intervention, and furthermore, in some instances allows infection control without mandatory removal of foreign material [6].

Hyperbaric oxygen counteracts the deleterious effects of local hypoxia on infection and wound healing by promoting neoangiogenesis, increasing local tissue perfusion, enhancing leukocyte killing potential [6]. It exerts direct antibacterial effect equivalent to antibiotics for strictly anaerobic bacteria. HBOT enhances osteoclastic activity to remove bony debris. Optimal oxygen tension enhances osteogenesis, neovascularisation to fill the dead space with vascular or bony tissue. HBOT improves host response by making the environment more favourable to leukocyte oxidative killing and resorption of dead and infected bone. Small bone debris could be resorbed during HBOT, but persistent sequestrum should be surgically removed [7].

The Zygoma receives arterial supply from the maxillary artery and from extensive anastomoses between these vessels and branches of the facial artery which nourish the periosteum [4]. The zygoma gives attachment to the zygomaticus major and minor and the masseter muscle. The integrity of this surrounding muscular envelope is of paramount importance for bone regeneration as it delivers oxygen, nutrients, and potential osteoprogenitor cells to the injured area. When this integrity is compromised as in the presence of large fistula or soft tissue necrosis, the effect of HBO therapy can be expected to be of suboptimal value.

HBOT although used widely for radiation-induced osteomyelitis of jaws [3], this is the first reported case in the literature where HBOT has been used for treatment of Zygomatic bone osteomyelitis. HBOT has successfully induced bone healing and remodelling with minimal residual sequestrum in the bone marrow in our case thereby restricting to a minimal surgery in contrast to an extensive one.

In conclusion, HBOT has the potential to be a very useful adjunct in the treatment of osteomyelitis in head and neck surgery; however, there is a need for carefully designed trials, avoiding methodological bias due to the great variability of patients, infectious agents, antibiotic resistance, host factors, to broaden the evidence of this therapeutic modality [6].

Funding

This case report did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sector.

Compliance with ethical standards

Competing interests

No competing interests.

Ethical approval

The institutional review board of Narayana Health provided ethical approval (Narayana Health Academic Ethics Committee, Approval number: NHH/AEC-CL-2020-499).

Patient consent

Patient consent obtained.