Septic arthritis is a purulent joint infection occurring when microorganisms invade the joint space, either through the haematological spread of a distant infection or post- iatrogenic direct joint inoculation.1,2 The latter can occur either due to traumatic joint exposure to a microorganism invasion or contiguous odontogenic, ear or skin infections.1,2 As the joint synovium is highly vascular and has no limiting basement membrane, it is more vulnerable to infection by haematological spread.3 Most infections are monoarticular; however, 10‒20% are polyarticular, with the knee being the most commonly involved joint.1 Septic arthritis usually affects the knee and the hip; it rarely affects smaller joints, such as the temporomandibular joint (TMJ).2,4,5 Septic arthritis of the TMJ is not commonly reported in the literature.2‒4,6 Delayed management of TMJ septic arthritis often leads to irreversible damage of the joint structure with subsequent long- term complications of bony deformity and ankylosis. This report presents two rare cases of TMJ ankylosis following a neonatal septic arthritis infection. Both patients were diagnosed with TMJ ankylosis between one to five years after the infection and presented clinically with facial asymmetry and trismus. 1Oral & Maxillofacial Surgery Programme, Oman Medical Specialty Board, Muscat, Oman; 2Department of Oral Health, Sultan Qaboos University Hospital, Muscat, Oman; 3Department of Oral & Maxillofacial Surgery, Al-Nahda Hospital, Muscat, Oman; 4Department of Oral & Maxillofacial Surgery, Oman Dental College, Muscat, Oman *Corresponding Author e-mail: dr.noorjabbar@ymail.com تصلب املفصل الصدغي الفكي كُمضاعفة لإللتهاب اإلنْتاين للمْفصل يف األطفال حديثي الوالدة تقرير عن حالتني نور ال�ساعدية، عبدالعزيز باكثري، اأحمد الها�سمي، حممد ال�سماعيلي abstract: Temporomandibular joint (TMJ) ankylosis as a complication of neonatal septic arthritis is rarely reported in the literature. We report two clinical cases of unilateral TMJ ankylosis occurring in paediatric patients subsequent to neonatal septic arthritis. The first case was a 15-month-old male infant who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in May 2010. According to the published English scientific literature, he is the youngest person yet to be diagnosed with this condition. The second case was a five-year-old female who presented to the Al-Nahda Hospital, Muscat, Oman, in October 2011. Both cases presented with facial asymmetry and trismus. They subsequently underwent gap arthroplasty and interpositional temporalis muscle and fascia grafts which resulted in an immediate improvement in mouth opening. Postoperatively, the patients underwent active jaw physiotherapy which was initially successful. Both patients were followed up for a minimum of two years following their surgeries. Keywords: Temporomandibular Joint; Ankylosis; Septic Arthritis; Children; Case Report; Oman. امللخ�ص: َق�َسط املف�سل ال�سدغي الفكي كُم�ساعفة لالإلتهاب الإْنتايِن للمف�سل ال�سدغي الفكي يف الطفال حديثي الولدة نادراً ما ُيذكر يف الأدب الطبي. يف هذا التقرير نعر�ض حالتني من َق�سٍط اأحادي اجلهة للمف�سل ال�سدغي الفكي لطفلني حديثي الولدة كاأحد م�ساعفات �ست احلالة الوىل لطفل يبلغ من العمر 15 �سهراً يف م�ست�سفى جامعة ال�سلطان قابو�ض يف اللتهاب الإنتاين للمف�سل ال�سدغي الفكي. �ُسخِّ مايو 2010، ومبراجعة الأدب الطبي املذكور باللغة الجنليزية ُيعترب هذا املري�ض اأ�سغر طفل يتم ت�سخي�سه بهذه احلالة، اأما احلالة الثانية فهي لطفلة تبلغ من العمر 5 �سنوات �ُسِخ�ست يف م�ست�سفى النه�سة يف اكتوبر 2011. كلتا احلالتني عانت من فقدان التناظر بني ن�سفي ل واحداث فجوة بني العظمتني الوجه ومن ال�زضز. مت اجراء عملية جراحية لفتح الق�سط ال�سدغي الفكي لكلتا احلالتني عن طريق َراأِْب امَلْف�سِ �ُسن وا�سح يف فتح الفم وحتريكه. مت اأخ�ساع املري�سني للعالج امللتحمتني ثم و�سع فا�سل من الع�سلة واللفافة ال�سدغية، مما نتج عنه حَتَ ية، ثم متت متابعة كلتا احلالتني ملدة �سنتني على الأقل بعد العملية. الطبيعي مبا�رسة بعد العملية مع نتائج اأولية ُمر�سِ مفتاح الكلمات: املف�سل ال�سدغي الفكي؛ الق�سط؛ التهاب املف�سل الإنتاين؛ اأطفال؛ تقرير حالة؛ عمان. Temporomandibular Joint Ankylosis as a Complication of Neonatal Septic Arthritis Report of two cases *Noor J. Al-Saadi,1 Abdulaziz A. Bakathir,2 Ahmed K. Al-Hashmi,3 Mohammad I. Al-Ismaili3,4 online case report Sultan Qaboos University Med J, November 2015, Vol. 15, Iss. 4, pp. e554–558, Epub. 23 Nov 15 Submitted 8 Feb 15 Revision Req. 25 May 15; Revision Recd. 19 Jun 15 Accepted 28 Jun 15 doi: 10.18295/squmj.2015.15.04.020 Noor J. Al-Saadi, Abdulaziz A. Bakathir, Ahmed K. Al-Hashmi and Mohammad I. Al-Ismaili Online Case Report | e555 Case 1 A 15-month-old boy presented to the Oral Health Department at Sultan Qaboos University Hospital, Muscat, Oman, in May 2010 with trismus and a chin misalignment [Figure 1A]. His medical history indicated that he had developed neonatal septic arthritis due to an umbilical cord infection at the age of 10 days old. At the time, the neonate had multiple joint swelling and pain involving both knees and hand joints. In addition, there were multiple subcutaneous infections at various sites, including the skin of the right pre-auricular region. Microbiological tests revealed the growth of Staphylococcus aureus. The infant recovered well following treatment with intravenous antibiotics. The patient presented again at the age of 10 months due to a recurrence of the infection in both knees and in multiple subcutaneous areas. He again responded well to intravenous antibiotics. There was no reported history of facial trauma or a fall at this time. A clinical examination showed that the 15-month- old child had a maximum mouth opening of 8 mm with facial asymmetry and chin deviation to the right. Maxillofacial computed tomography (CT) showed gross enlargement and deformation of the right condylar head with evidence of fusion with the base of the skull. This led to a diagnosis of right TMJ ankylosis [Figures 1B & C]. At the age of 16 months, the child underwent gap arthroplasty with interpositional temporalis muscle and fascia grafts with removal of the ipsilateral coronoid process under general anaesthesia to release the right TMJ ankylosis. The mouth opening was increased intraoperatively from 8 mm to 24 mm. Recovery during the postoperative period was uneventful and the patient immediately began jaw exercises and physiotherapy. At a six-month postoperative review, the patient was able to maintain a mouth opening of 30 mm with satisfactory lateral movement. When he was three years old, the patient was found to have a maximum mouth opening of 22 mm. A CT scan revealed growth of the condylar head on the mediolateral aspect and a U-shaped condylar head on the coronal aspect. A bony overgrowth was seen extending from the cranial aspect into the condylar depression [Figure 2A]. His parents were reluctant to proceed with any further surgical interventions, so the patient was closely monitored with continuous physiotherapy and jaw exercises. At five years of age, the trismus had worsened with a maximum mouth opening of 13 mm. An orthopantomogram showed that the bony mass of the deformed right condyle had increased and the gap space had decreased, indicating a recurrence of the right TMJ ankylosis [Figure 2B]. The patient was operated on again to release the ankylosis under Figure 1A–C: A 15-month-old boy presented with (A) trismus and chin misalignment. Computed tomography scans in the (B) coronal and (C) sagittal aspects revealed severe bony deformation and ankylosis of the right temporoman- dibular joint. Temporomandibular Joint Ankylosis as a Complication of Neonatal Septic Arthritis Report of two cases e556 | SQU Medical Journal, November 2015, Volume 15, Issue 4 improved and the patient could open her mouth to 40 mm. Discussion TMJ septic arthritis is an infection of the joint space that can lead to many complications, including intracranial abscesses, growth impairment and deformity of the condyle and destruction of the joint. Subsequent TMJ ankylosis can be a long-term complication.4 TMJ ankylosis is the replacement of normal joint articulation with fibrous, fibro-osseous or bony tissues which results in partial or complete fusion of the mandibular condyle to the base of the skull.5 It is the most severe long-term complication of septic arthritis and has a devastating presentation. The long-term effect of joint deformity and ankylosis is unpredictable, depending on the degree of joint damage, type of ankylosis and age of the patient.5 As such, each case is unique and should be assessed individually. In the paediatric population, patients with bilateral TMJ ankylosis usually present with facial deformity, trismus and dysmasesis.5 Deviation of the jaw when the mouth is open and facial asymmetry are the usual presentations of unilateral TMJ.5,7 Owing to the gradual nature of the joint deformity and ankylosis, it may take several months or years before the facial deformity is noticed and medical treatment is sought, as was the case for the patients described in the current report. Both cases presented with facial asymmetry due to the TMJ deformity, growth deficiency of the affected condyle and ramus, misalignment of the chin and mandible to the affected side and trismus. These findings are in line with previously published cases.5,7 According to the available English literature, there were 29 reported cases of septic arthritis involving general anaesthesia and the intraoperative mouth opening was increased from 13 mm to 32 mm. The postoperative recovery period was uneventful and the patient again began jaw exercises and physiotherapy. Case 2 A five-year-old girl presented to the Oral & Maxi- llofacial Surgery Unit of Al-Nahda Hospital, Muscat, Oman, in October 2011 with a complaint of longstanding trismus [Figure 3A]. Her medical history indicated neonatal septic arthritis occurring on the second day post-delivery and manifesting as a high fever with painful swelling of the left knee. There was no record of the causative microorganism for the infection. The neonate was treated with intravenous antibiotics for three weeks, followed by a one-month oral antibacterial course. She recovered well but suffered a recurrence of the knee swelling one year later which was again successfully treated with antibiotics. At the age of five years, the patient had a maximum mouth opening of 5 mm, restriction of the lateral jaw movements and clinically apparent facial asymmetry with chin misalignment [Figure 3B]. CT scans showed a bony deformation of the left TMJ with reduced joint space and partial fusion of the condylar head with the base of the skull, which confirmed the diagnosis of left TMJ ankylosis [Figures 3C & D]. The patient underwent a gap arthroplasty with interpositional temporalis muscle and fascia grafts. This improved her mouth opening ability from 5 mm to 27 mm. Postoperatively, the recovery period was uneventful and was followed by immediate jaw exer- cises and physiotherapy. At a six-month postoperative review, the patient maintained satisfactory mouth opening and lateral mandibular movements. At a two-year follow-up, the mouth opening had further Figure 2A & B: A: Coronal computed tomography scan of the patient at three years old showing mediolateral temporomandibular joint (TMJ) bony overgrowth resulting in a U-shaped deformity, shortening of the mandibular ramus and downward overgrowth of the cranial bone into the deformed U-shaped condyle. B: Orthopantomogram of the patient at five years old showing right TMJ bony deformity and a reduced gap with a short ramus in comparison to the normal left side. Noor J. Al-Saadi, Abdulaziz A. Bakathir, Ahmed K. Al-Hashmi and Mohammad I. Al-Ismaili Online Case Report | e557 the TMJ from 1931–2011, with only four cases of ankylosis subsequent to septic arthritis in neonates.7,8 The current report adds two rare cases of neonatal septic arthritis that resulted in TMJ ankylosis after the haematogenous spread of a distant systemic infection involving multiple joints. In addition, to the best of the authors’ knowledge, the first case represents the youngest child so far to be diagnosed and treated for TMJ ankylosis due to neonatal septic arthritis. Septic arthritis can be caused by bacteria, viruses, fungi or parasites. The most common isolated causative bacteria are Gram-positive S. aureus and Streptococcus.1,4 Gram-negative bacilli are found in 20‒50% of neonates, the elderly, intravenous drug users and the immunocompromised.1,4 S. aureus was found to be the causative agent in the first case of the current report. Unfortunately, the microorganism in the second case was unknown. Joint infections initiate an inflammatory response in the host which is responsible for much of the joint destruction. Inflammation leads to synovial hyperplasia and subsequent intra-articular abscess formation. This, in turn, leads to increased intra- articular pressure with subsequent diminished joint blood flow, ischaemia and necrosis of the cartilage.1,6 Intra-articular cartilage damage may be seen after only three days, with irreversible changes in joint structure occurring as early as seven days.1,6 Acute TMJ infections manifest clinically as severe joint pain, trismus, acute malocclusion, contralateral deviation on opening, preauricular erythema and swelling.4,6 Radiographical assessment is essential in evaluating the extent and nature of the TMJ ankylosis following septic arthritis. The ankylosis will usually appear as an ill-defined radiopaque mass with partial or complete fusion between the mandibular condyle, glenoid fossa, articular eminence and base of the skull with an irregular overgrowth. A plain radiograph can underestimate the extent of the ankylotic mass as it gives no information about the anatomy medial to the condyle.9 A CT scan is more diagnostically useful and was hence used to evaluate the extent of ankylosis in both of the cases reported here. Surgical management of TMJ ankylosis continues to be a challenge in children. Different surgical tech- niques have been reported in the literature, including gap or interpositional arthroplasty and wide excision of the ankylotic mass with varying methods of reconstruction.5,7 However, no single method has yet reported complete success. This is likely due to the challenging nature of this condition, poor compliance with postoperative physiotherapy and the unavoidable Figure 3A–D: A five-year-old girl presented with (A) trismus and (B) a deviated chin to the left. Computed tomography scans in the (C) coronal and (D) sagittal aspects showed left temporomandibular joint bone deformity and ankylosis with a shortened left mandibular ramus. Temporomandibular Joint Ankylosis as a Complication of Neonatal Septic Arthritis Report of two cases e558 | SQU Medical Journal, November 2015, Volume 15, Issue 4 arthritis is critical in preventing and avoiding such complications. References 1. Ohl CA, Forster D. Infectious arthritis of native joints. In: Bennett E, Dolin R, Blaser M, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, Pennsylvania, USA: Saunders, 2015. Pp. 1302–17. 2. Cai XY, Yang C, Zhang ZY, Qiu WL, Chen MJ, Zhang SY. Septic arthritis of the temporomandibular joint: A retrospective review of 40 cases. J Oral Maxillofac Surg 2010; 68:731–8. doi: 10.1016/j.joms.2009.07.060. 3. Lynn MM, Mathews CJ. Advances in the management of bacterial septic arthritis. Int J Clin Rheumatol 2012; 7:335–42. doi: 10.2217/ijr.12.11. 4. Leighty SM, Spach DH, Myall RW, Burns JL. Septic arthritis of the temporomandibular joint: Review of the literature and report of two cases in children. Int J Oral Maxillofac Surg 1993; 22:292–7. doi: 10.1016/S0901-5027(05)80519-3. 5. Kaban LB, Bouchard C, Troulis MJ. A protocol for management of temporomandibular joint ankylosis in children. J Oral Maxillofac Surg 2009; 67:1966–78. doi: 10.1016/j.joms.2009 .03.071. 6. Goldschmidt MJ, Butterfield KJ, Goracy ES, Goldberg MH. Streptococcal infection of the temporomandibular joint of hematogenous origin: A case report and contemporary therapy. J Oral Maxillofac Surg 2002; 60:1347–53. doi: 10.1053/ joms.2002.35736. 7. Chaves Netto HD, Nascimento FF, Chaves Md, Chaves LM, Negreiros Lyrio MC, Mazzonetto R. TMJ ankylosis after neonatal septic arthritis: Literature review and two case reports. Oral Maxillofac Surg 2011; 15:113–19. doi: 10.1007/ s10006-010-0210-4. 8. Sembronio S, Albiero AM, Robiony M, Costa F, Toro C, Politi M. Septic arthritis of the temporomandibular joint successfully treated with arthroscopic lysis and lavage: Case report and review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 103:e1–6. doi: 10.1016/j. tripleo.2006.08.028. 9. Sanders R, MacEwen CJ, McCulloch AS. The value of skull radiography in ophthalmology. Acta Radiol 1994; 35:429–33. doi: 10.1177/028418519403500506. complication of relapse and recurrence of the ankylosis, as with the first case reported here. Most published reports of TMJ ankylosis following septic arthritis only provide short-term follow-up periods of less than one year.7 However, the patients in the present case report were followed up for a minimum of two years following surgical release of the TMJ ankylosis. Long- term follow-up will continue with these patients until they reach early adulthood in order to monitor facial growth and to detect any further complications. Conclusion TMJ neonatal septic arthritis is uncommon and early recognition is crucial. Delayed diagnosis and management can lead to devastating functional and aesthetic complications of facial deformity, trismus and dysmasesis due to the progressive and permanent joint distortion, overgrowth and gradual fusion with the base of the skull. The management of such compli- cations is challenging with low success rates and a high likelihood of relapse and recurrence of the ankylosis. Rapid diagnosis and treatment of the TMJ septic http://dx.doi.org/10.1016/j.joms.2009.07.060 http://dx.doi.org/10.2217/ijr.12.11 http://dx.doi.org/10.1016/S0901-5027%2805%2980519-3 http://dx.doi.org/10.1016/j.joms.2009.03.071 http://dx.doi.org/10.1016/j.joms.2009.03.071 http://dx.doi.org/10.1053/joms.2002.35736 http://dx.doi.org/10.1053/joms.2002.35736 http://dx.doi.org/10.1007/s10006-010-0210-4 http://dx.doi.org/10.1007/s10006-010-0210-4 http://dx.doi.org/10.1016/j.tripleo.2006.08.028 http://dx.doi.org/10.1016/j.tripleo.2006.08.028 http://dx.doi.org/10.1177/028418519403500506