Abstract
Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome is a rare group of sterile, inflammatory osteoarticular disorders classically associated with skin manifestations. The etiology is unknown but probably involves genetic, infectious, and immunological components. The characteristic feature of the disease is found in the bone lesions, which typically involve the anterior chest wall and axial skeleton. In the literature review, six case reports discussed involvement of the TMJ. Treatment of SAPHO is geared toward symptom management as there is no cure. Surgery for mandibular lesions is usually a last resort as results are reported to be temporary with symptoms recurring within a year. Surgery appears to be performed early after diagnosis of TMJ related pathology; probably because lesions affecting the TMJ involve some limitation in mouth opening with varying degrees of ankylosis. The authors provide a literature review and describe a case of SAPHO syndrome with ankylosis of the left TMJ. The patient was treated with joint reconstruction using a patient-fitted total joint prosthesis (TMJ Concepts Inc., Ventura CA) in single stage surgery. This paper is the first to report maxillary involvement in SAPHO syndrome.
SAPHO represents a combination of lesions that affect the bones, joints, and skin. It is an acronym for synovitis, acne pustulosis, hyperostosis, and osteitis, which was coined by C hamot et al. in 1987. It is considered rare, with an annual prevalence of 1/10,000 . SAPHO can occur at any age, but is more common in childhood and early adulthood; it is rare beyond the sixth decade of life. There is a female predilection . The current diagnostic criteria are listed in Table 1 . The etiology of SAPHO remains unknown and may involve a combination of genetic, infectious, and immunological components .
| Inclusion |
| Bone ± joint involvement associated with PPP and psoriasis vulgaris |
| Bone ± joint involvement associated with severe acne |
| Isolated a sterile hyperostosis/osteitis (adults) |
| Chronic recurrent multifocal osteomyelitis (children) |
| Bone ± joint involvement associated with chronic bowel diseases |
| Exclusion |
| Infectious osteitis |
| Tumoral conditions of the bone |
| Non-inflammatory condensing lesions of the bone |
A thorough physical examination, laboratory tests, plain films, computed tomography (CT) scans, magnetic resonance imaging (MRI), nuclear bone scans, bone biopsy, and other evaluations may aid in the diagnosis of SAPHO syndrome. The nuclear bone scan is extremely sensitive in the detection of anterior chest wall lesions . Most laboratory tests return in the normal range with the occasional exception of an elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) . The diagnosis is challenging because not all symptoms ( Table 2 ) are present in each patient and when they are present, some may be subtle .
| Age | Occurs at any age. Rare beyond sixth decade of life |
|---|---|
| Etiology | Possible combination of genetics, infectious and immunological components |
| Laboratory tests | Usually normal. Occasional elevated ESR or CRP |
| Skin lesion | Present in 25% of cases |
| Bone lesions | Characteristic features. Bones commonly affected: sternum, ribs, clavicles. Mandible involved in 10% of cases |
| Joint involvement | Proposed to originate by an extension of an osteitis adjacent to articular structures |
| TMJ involvement | Rare. When exist is related to ankylosis |
Skin lesions may precede, occur simultaneously, or follow the onset of osteoarticular manifestations . The absence of skin lesions does not exclude SAPHO as a diagnosis; skin lesions may be absent in 25% of cases .
The characteristic feature of SAPHO is found in the bone lesions. The sternum, ribs, and clavicles are most commonly affected ; the spine, sacrum, ilium, and peripheral long bones are involved to a lesser degree . The mandible is involved in about 10% of cases and lesions are typically described as ill-defined radiolucent lesions with evidence of osteitis and sclerosis. Periosteal thickening and hyperostosis are often present with mandibular involvement. The posterior body and ascending ramus are the most common sites affected . More commonly there is swelling and pain without suppuration , and/or limitation of motion .
The clinical condition chronic recurrent multifocal osteomyelitis is now recognized as a form of SAPHO syndrome, occurring primarily in children and young adults . Diffuse sclerosing osteomyelitis of the mandible (DSOM) was originally described as a stomatological disease, but many patients also had palmoplantar pustulosis (PPP), various forms of psoriasis, and/or osteitis at other sites. DSOM is now recognized as the mandibular manifestation of SAPHO syndrome .
Joint involvement is proposed to originate by extension of an osteitis adjacent to articular structures , and occurs as acute pseudoinfectious arthritis mimicking a bacterial disease or as chronic lesions that mainly affect larger joints such as the sternocostal and sternoclavicular joints, sacroiliac joint, and hip joints; the temporomandibular joint (TMJ) has rarely been cited . SAPHO involvement in the TMJ may predispose to ankylosis and is thought to occur by encroachment of mandibular osteitis on the adjacent joint ( Table 2 ).
In this article, the authors present a literature review and a case report of SAPHO syndrome presenting with ankylosis of the left TMJ, treated with joint reconstruction using a patient-fitted total joint prosthesis (TMJ Concepts Inc., Ventura, CA, USA) in single stage surgery.
Literature review
It is commonly suggested that SAPHO is a form of seronegative spondyloarthropathy because of its association with psoriasis, psoriatic arthritis, sacroiliitis, increased incidence of inflammatory bowel disease, and the prominent axial involvement . The HLA-B27 haplotype is less frequent in SAPHO syndrome than in other forms of spondyloarthropathies . Several genes are being studied because of numerous clinical similarities between SAPHO and other autoinflammatory syndromes with a genetic basis. The results are inconclusive and the impact of genetics in SAPHO syndrome has not been identified.
Evidence suggests that SAPHO may be mediated by immunological pathways. SAPHO syndrome is associated with elevated levels of the pro-inflammatory cytokines interleukin-8 (IL-8) and IL-18 , and the pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), may be involved in generating and perpetuating rheumatic manifestations of SAPHO . There are varying degrees of immune system dysfunction in SAPHO . In some reports, the humoral immune response is hyperactive and in others it is hypoactive. The cell-mediated immune response has been reported as normal or hyperactive; others report total immune system impairment . Another etiological hypothesis proposes that a low-virulence organism triggers an immune response in the bone which, over time, becomes a chronic, indolent infection. Most osteomyelitic bone lesions are aseptic, which implies the absence of bacteria or the presence of fastidious bacteria that are difficult to isolate and culture . Pathogens that have been isolated from the skin and joint fluid include Staphylococcus aureus , Staphylococcus epidermidis , and Proprionibacterium acnes ; species isolated from mandibular lesions include Veillonella , Eikenella , and Actinomyces . P. acnes is frequently isolated and may be a source of the chronic infection found in SAPHO . P. acnes has been shown to activate the immune system, induce the pro-inflammatory cytokines IL-1, IL-8, and TNF-α, and trigger a nonspecific activation of cell-mediated immunity .
The etiology of SAPHO is probably multifactorial and involves interaction between the patient’s genetics, immune system status, and infection. It is plausible that a low-virulence bacterium initially stimulates an immune response leading to the development of a chronic indolent infection . Genetics may influence the process, the extent of which is to be determined.
The skin lesions of SAPHO may be subtle and vary in severity; women more often develop PPP while men typically develop more severe forms of acne . Skin lesions may include forms of PPP, pustular psoriasis, acne conglobata, acne fulminans, and hidradenitis suppurativa . Overall the dermatologic manifestations are difficult to eradicate and show a protracted course of remissions and exacerbations . Skin treatments include topical corticosteroids, tetracycline and other antimicrobials, retinoids, psoralen-ultraviolet A therapy, intravenous isotretinoin, and many others . Improvement of the skin lesions usually parallels improvement in the bone lesions .
The characteristic feature of SAPHO is the bone lesions. The mandible is involved in approximately 10% of cases ; TMJ involvement is rare with very few case reports in the literature . In a review of 120 patients with SAPHO syndrome, only one had mandibular osteitis extending to the TMJ . Table 3 presents six articles in which SAPHO involved the TMJ.
| Study | Gender | Age | Bone site | TMJ’s involved | Surgical treatment (# of surgeries performed) | Follow-up (years) | Outcome |
|---|---|---|---|---|---|---|---|
| M arsot -D upuch et al. | Male | 57 | Temporal squama, mandible, ramus, condyle | 1 | None | 1 | – Skin improved – Infratemporal lesion decreased – Deafness persisted |
| E yrich et al. | Female | 26 | Mandible, ramus, coronoid, and condyle | 1 | 1. Partial condylar resection 2. Full resection with costal graft 3. Resection with reconstruction plate |
12 | – Asymptomatic |
| U tumi et al. | Male | 32 | Mandible, ramus, condyle | 2 | 1. High bilateral condylectomy | 2 | – No recurrence – Skin lesions controlled |
| M uller -R ichter et al. | Female | 42 | Mandible, ramus, condyle | 1 | 1. Two decortications 2. Condyle resection and alloplastic condylar reconstruction with reconstruction plate |
2 | – Asymptomatic – Return to normal diet and speech |
| Y anamoto et al. | Female | 51 | Ramus and condyle | 1 | 1. Partial resection of the condyle 2. Mandibular decortication |
8 | – Symptom management |
| M c P hillips et al. Present case | Male | 47 | Mandible, maxilla, ramus, condyle | 1 | 1. Resection of the condyle and alloplastic reconstruction with total joint prosthesis and fat graft | 2 | – Symptom management – No recurrence |
Case report
A 46-year-old Caucasian male was referred for evaluation of worsening trismus, severe left TMJ pain, loss of jaw function, limited range of motion, difficulties with mastication, and severe tinnitus. The patient’s history revealed that, in 1983, he was involved in a flood after which he and his wife noted water discoloration. They reported it to the local health authorities and were assured the water pipes were being flushed, the water was safe, and that it would subside. After months of drinking, bathing and showering as normal, they found the septic tank had backed up into the water line.
In 1987, the patient began to develop lumps on his sternum that caused pain with exercise. A chest CT scan showed calcifications in his rib cage and sternum. A bone scan revealed increased uptake in his anterior chest wall. In 1989, he developed pustular lesions on the palms of his hands and soles of his feet. Reportedly, his wife had similar symptoms but was not evaluated by the authors. For years the patient was treated with corticosteroids, with limited success. He was subsequently diagnosed with multiple sclerosis (MS) and underwent treatment with Campath (alemtuzumab), a monoclonal antibody, as part of a clinical trial.
His TMJ symptoms began in 1992 and included bruxism. Cortisone was injected four times into the bilateral temporalis and masseter muscles and botox was injected into the left masseter twice for pain relief. His condition worsened with limited mouth opening. An MRI in 2002, showed left TMJ arthritis with a non-reducing anteriorly displaced disc and a normal right TMJ.
In 2005, he was referred to the senior author (LMW) for evaluation. He had good facial symmetry, and a class I occlusion. Maximum incisal opening was 14 mm with a 1 mm right and 5 mm left excursive movement. He had significant tenderness to palpation over the left masseter, TMJ, styloid, and sternocleidomastoid with left TMJ crepitation ( Table 4 ).
| Onset | In 1983, patient involved in a flood. After months of drinking, bathing and showering as normal, they found the septic tank had back up into the water line |
| First signs and symptoms | In 1987 the patient began to develop lumps on his sternum Two years after that he developed pustular lesions on the palms of his hands and soles of his feet |
| Clinical examination (2005) | – Good facial symmetry – Class I occlusion – 14 mm incisal opening – 1 mm right and 5 mm left excursive movements – Tenderness to palpation on left masseter, TMJ, SCM |
| CT scan images | – Reactive cortical thickening, permeative radiolucencies, areas of osteitis – Condyle showed degenerative changes and ankylosis to the eminence – Masseteric hypertrophy with calcifications and fibrosis |
| MRI images | – Condyle with arthritic changes, degenerated displaced articular discs – Bony ankylosis |
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