Extra-platysma fixation of bisphosphonate-related mandibular fractures: a suggested technical solution

Abstract

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an evolving epidemic. Often the patients are in poor general condition and therefore the aim of surgical treatment is generally limited to pain control and restoration of feeding ability. We present a useful surgical technique for the stabilization of BRONJ-related mandibular fractures, including application of a reconstructive plate. With an extraoral approach, a 2.5-mm reconstructive locking plate is contoured and placed in the plane of dissection, superficial to the platysma. The fracture site is accessed through an intraoral approach, which limits surgery to curettage and rinsing of the surgical site. Since there is no removal of the periosteal support to the residual stumps, the blood supply to the affected mandible is maintained. Avoidance of direct contact of the infected fractured site with the reconstructive plate is another advantage of working in a surgical plane over the platysma muscle. Although fracture healing is not achieved, plate fixation with this technique is stable and painless and patients can easily eat; therefore, patients enjoy a great improvement in their quality of life. We consider this easy and effective procedure to be a reliable palliative solution in these patients.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an evolving epidemic encountered by maxillofacial surgeons. Since the first report of BRONJ described by Marx in 2003, many new cases have been described, but the causes of this disease are still debated. The most widely accepted etiopathological hypothesis proposes that in certain individuals, bisphosphonates increase trabecular bone density, inducing vascular insufficiency and causing bone necrosis. The devascularized bone is then highly susceptible to infection.

Most surgeons advise prevention and conservative symptomatic treatment consisting of the simple removal of the necrotic bone. At times, further surgical treatment becomes necessary if infection-induced pain and inflammation are not relieved by simple sequestrum removal. Often, conservative treatments do not halt disease progression, and the pathological situation advances to a worsening clinical grade, requiring more complex management. The necrosis can evolve and produce an extraoral fistula and osteolysis extending to the inferior border, which can progress to mandibular fracture ( Fig. 1 ). In the literature there are very few reports of the treatment of pathological mandibular fracture caused by BRONJ.

Fig. 1
Panoramic radiograph revealing wide bone destruction in the anterior region of the mandible, and a pathological fracture in the right body.

Often the patients are in poor general condition and concurrently suffering from metastatic cancer. Moreover, the long clinical history of local infection and chronic antibiotic therapy often leads to depleted energy reserves. Due to these conditions, the aim of surgical treatment in generally limited to pain control and restoration of feeding ability. There are reports of segmental resection and direct sub-periosteal open reduction of the fracture, with or without stabilization using a reconstruction Plate.

The circumstances surrounding BRONJ-related fractures may not be recommended for traditional open surgery with direct positioning and plate stabilization, due to the high risk of increased reduction of vascular flow to the bone stumps. Moreover, the rigid fixation is likely to fail due to infection in the plates and screws and the presence of pus in the surgical field. These conditions impair fracture healing and maintain infection.

Here, we present a useful surgical technique for the stabilization of BRONJ-related mandibular fractures, including application of an extra-platysma reconstructive plate, with no contact between the osteosynthesis material and the infected mandibular site. Although fracture healing is not achieved, plate fixation with this technique is stable and painless and patients can easily eat; therefore, patients enjoy a great improvement in their quality of life.

Surgical technique

Five minutes prior to the start of surgery, 1:200,000 epinephrine is injected subcutaneously along the mandible and into the submandibular region. A 10-cm skin incision is made that is set on a well-defined submandibular wrinkle a few cm inferior to the mandibular border. A dissection in a surgical plane over the platysma muscle is then performed, 5 cm in the front and 5 cm in the back, to the fracture site.

Fracture reduction is achieved manually, without any visual control of the rim. Further, individual occlusion is restored and maintained temporarily solely by hand pressure. No maxillo-mandibular fixation is applied in order to avoid the possible onset of newBRONJ sites.

A 2.5-mm reconstructive locking plate is modelled and placed in the plane of surgical dissection, superficial to the platysma ( Fig. 2 ). Screws are placed a few cm distant from the palpable bone fracture, which is not in direct sight of the marginal mandibular branches of the facial nerve.

Fig. 2
Intraoperative view: the position of the 2.5-mm plate in the extra-platysmatic plane.

Meticulous haemostasis and the application of an aesthetic, well-hidden suture finish the extraoral surgical procedure. The cervical suture is covered by a dressing, and the fracture site is accessed through a minimal intraoral approach that limits surgery to curettage and rinsing of the surgical site.

Discussion

BRONJ is a clinical situation that is increasingly observed. The effectiveness of the drugs in preventing bone pain and resorption in osteoporosis, and in controlling bone metastasis in the oncologic population, has led to the increased use of this therapy. This situation can occur with both the oral and systemic administration of bisphosphonates, the latter being more risky. The cumulative incidence of BRONJ ranges from 0.8% to 12%, and these values are increasing over time.

In their updated guidelines of 2009, The American Association of Oral and Maxillofacial Surgeons (AAOMS) provides guidance to clinicians regarding risk factors for developing BRONJ and information related to the diagnosis and management of patients with BRONJ. In this paper, the AAOMS also proposes a modified staging system that is used to more accurately stratify patients, as outlined below. The at-risk category includes asymptomatic patients previously treated with either oral or intravenous bisphosphonates.

  • Stage 0: No clinical evidence of necrotic bone, but nonspecific clinical findings and symptoms.

  • Stage 1: Exposed necrotic bone, asymptomatic, and with no evidence of infection.

  • Stage 2: Exposed and necrotic bone associated with infection as evidenced by pain and erythema in the region of exposed bone, with or without purulent drainage.

  • Stage 3: Exposed and necrotic bone in patients with pain, infection, and one or more of the following: exposed and necrotic bone extending beyond the region of alveolar bone, resulting in pathologic fracture; extraoral fistula; oral antral/oral nasal communication; and osteolysis extending to the inferior border of the mandible or the sinus floor.

A simple removal of the exposed intraoral bone is advised as a conservative treatment in the early stages. When approaching more complex clinical situations, as with stage 3 patients who have pathological fractures, the optimum management is not currently standardized. These patients typically have pain that impacts their quality of life. Surgical debridement/resection, in combination with antibiotic therapy, may offer a long-term palliative and valid solution.

Aarabi et al. proposed the management of a pathological fracture of the mandibular angle that includes removal of bone sequestrum and resectioning until uninvolved bone is reached. The stumps of the fractured mandible are covered by a platysma muscle flap without the reestablishment of mandibular continuity. Maintenance of the occlusion with an orthodontic appliance for 12 weeks postoperatively was suggested. Although this is a good method for achieving long-term palliation, no attempts to heal the fracture are made, and the formation of a simple rigid scar may not be enough to re-establish individual occlusion.

Conversely, there are authors who suggest resection with traditional internal fixation. Wongchuensoontorn et al. presented three patients with BRONJ-related fractures who were treated with mandibular resection and internal rigid fixation with 2.4-mm locking plates. One patient died 6 months after the operation; therefore, a follow-up was impossible. The second patient suffered progression of BRONJ on the resected stumps at 6 months, but also demonstrated stable osteosynthesis. The third patient showed stable results at 6 months.

The disadvantages of this simple treatment approach are, in our opinion, exposing the unaffected bone, which reduces the vascular flow to the mandible, and allowing communication of the infected site of the fracture with the reconstructive plate. This condition can easily disrupt the long-term stability of osteosynthesis and maintain active infection at the site indefinitely.

In the literature, there are reports describing how immediate reconstruction after resection of the mandible affected by BRONJ is possible. Nocini et al. reported on a successful vascularized fibula free flap reconstruction after mandibular resection in seven patients, with a mean follow-up period of 23 months. They chose this radical treatment for BRONJ since they had previously shown that a properly planned surgical resection has a high curative potential in BRONJ patients. They surmised that in selected patients, this is a reliable solution to guarantee a long-term solution to BRONJ.

Due to the general clinical condition of patients with BRONJ-related mandibular fractures, it is not feasible to operate on patients with such long microsurgical reconstructions, as there is a high risk of perioperative complications and free flap loss.

Coletti and Ord reported on the reconstruction of the resected mandible with bone grafts, in which the graft itself survived, but a non-union between the surface mandible/bone graft was observed.

In patients at an advanced stage of BRONJ with mandibular fracture, the more troublesome problems are pain and the limitation of masticatory function in those who are compromised clinically. Secondary reconstructive options can be considered if the patient’s general condition is appropriate and the patient requests this.

Applying the well-known concepts of fracture reduction and stabilization in the atrophic jaw, where care is taken not to reduce bone vascularization of the weak mandible, we propose an extraoral approach using fracture stabilization in a plane superficial to the platysma muscle. Use of this surgical plane carries no risk of injuries to the facial nerve since the marginal mandibular branch lies ventrally. A complete loss of function in the marginal mandibular nerve is not likely, although, in theory, temporary partial damage of one branch of the nerve could occur during rigid fixation, while holes are drilled for subsequent screws. Since there is no removal of the periosteal support to the residual stumps, blood support to the affected mandible is maintained. In addition, avoidance of direct contact of the infected fractured site with the reconstructive plate is another advantage of working in such a superficial plane.

Occlusion is achieved by direct reduction and maintained by holding the stumps in the correct position. The technique is performed without the use of intermaxillary screw fixation to avoid further development of BRONJ at other sites. To reduce the risk of further BRONJ formation, screws are slowly drilled and copious lavage with rinsing solution is used. The skin incision is made 2 cm inferior to the mandibular border, not only for aesthetic purposes, but also to avoid the decubitus of the reconstructive plate with its expulsion.

The use of a locking plate is essential in order to maintain the obtained occlusion position and to avoid excess pressure on the platysma muscle and periosteum, therefore preventing interference with the blood supply to soft and hard tissues and injuries to the underlying marginal mandibular nerve.

The oral approach stage of the operation is limited to curettage and rinsing of the surgical site. Plate contamination and the formation of major abscesses can be prevented by the persistence of an oral exposure or draining fistula.

Rapid relief and preservation of normal masticatory function is achieved, and the patient recovers safely and quickly. The typical discharge time is 2 days post-surgery. The results are stable over time, even if healing of the fracture is not accomplished ( Figs 3 and 4 ). Another advantage for these compromised patients is the ease and speed with which this surgical procedure is performed. However, even with this procedure, BRONJ may be observed years later, and sequelae such as plate exposure, infection, and instability, with subsequent plate removal and mandibular resection, may occur. We consider this easy and effective procedure to be a reliable palliative solution in these patients. Therefore, this option is an advancement in the treatment of this disease.

Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Extra-platysma fixation of bisphosphonate-related mandibular fractures: a suggested technical solution
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