Loose bodies in right elbow joint: Post traumatic? or post infective?

Tuberculous osteomyelitis after open fracture is uncommon. Early diagnosis of tubercular arthritis is difficult because of insidious onset, indolent process and mild or non specific local or systemic symptoms. This case report describes the fibrinous loose bodies in elbow joint of a patient who sustained a compound fracture presented with chronic non healing discharging sinus. Intra-operatively some suspected seed like bodies were removed and sent for histopathological examination which showed circumscribed homogenous fibrinous bodies with focal area of hyalinization and few embedded tiny osteolytic fragments. Acid Fast Bacilli staining was positive. The patient had a good recovery after treatment with anti-tuberculosis drugs.

INTRODUCTION

Extra axial osteo articular tuberculosis occurs mainly in weight bearing joints like hip, knee, sacroiliac joints followed by shoulder, ribs, ankle, wrist and elbow. Tuberculosis of a joint may result from haematogenous dissemination through the sub synovial vessels, or metaphyseal (more common in children) lesions that erode into the joint and from traumatic open injuries. Tubercular arthritis occurring in the upper extremities is rare, accountings for 1-5% of musculoskeletal tuberculosis[1-4] and 10% to 35% of extra pulmonary tuberculosis.[5] Tubercular osteomyelitis after an injury in extremity is a rare entity. There are only few reports of accidental inoculation of tubercle bacilli into damaged skin. Its infrequent occurrence and random symptoms often result in misdiagnosis or delayed diagnosis, which may lead to joint deformity. Our case report describes the fibrinous loose bodies in elbow joint. Loose bodies are fragments of bone or cartilage that freely float in the joint space. Fibrinous loose bodies results from bleeding within the joint or from the death of the synovial membrane. They resemble rice grains, melon seeds, or may be irregular in shape. Histologically homogenous and concentrically laminated masses of fibrin are seen. The importance of the loose body had lead to the incidental diagnosis of localized tubercular arthritis in this patient as a result of open injury.

CASE REPORT

We report a 30 year old man referred to our institution for road traffic accident and presented with pain, swelling, deformity, Gustilo grade 3A open wound in right elbow with compound fracture. His personal and family history was not significant. The patient has no history of fever, anorexia, weight loss and night sweats.

Plain radiograph revealed a compound intercondylar fracture right humerus with communited right olecranon. Open reduction and internal fixation after proper debridement with plates was performed. On the 5th post-surgical day, patient had sero sangious discharge from the operative wound, for which debridement was done. After repeated debridement's and wound closure patient was sent home. The patient came with chronic discharging sinus from the wound over posterolateral aspect of elbow, for which repeated pus culture and serological tests were performed, which was found to be negative. Prophylactic broad spectrum antibiotic therapy was started for 6 weeks but the patient still had persistent discharging sinus. Six months later the patient returned to outpatient clinic with recurrence of discharging sinus, pain associated with increased range of motion, hyper and abnormal mobility. On earlier plain radiography, there were no notable findings, however after 6 months implant failure was revealed [Figure 1], with joint space narrowing and peri articular osteopenia. Laboratory investigations included hematocrit value of 36.6%, total leukocyte count was normal, ESR was 57mm/hour, and C-reactive protein was 6 mg/dl. Rheumatoid factor and anti-nuclear anti-body was negative. Pus culture was negative. Patient underwent thorough generalized clinical and radiological examination. Various specimens like sputum and urine were send for ZN staining but there was lack of any primary foci elsewhere in his body.

Figure 1

Anteroposterior and lateral X-ray of right elbow of the patient, 6 months post injuryshows diffuse joint space narrowing, multiple marginal and central bone erosions, a significant amount of joint effusion, and slight periarticular osteoporosis

Repeat debridement and implant removal was performed. Some suspicious rice seed like bodies were removed and sent for histopathological examination. Histological examination [Figure 2] showed circumscribed homogenous fibrinous bodies with focal area of hyalinization and scanty focal acute inflammatory infiltrate. Few bodies had embedded tiny osteolytic fragments. Acid Fast Bacilli staining (Ziehl-Neelsen Staining) was done and found positive.

Figure 2

Histological examination showing circumscribed homogenous fibrinous loose bodies with focal areas of hyalinization

Patient was started with anti tubercular four-agent drug treatment using isoniazid, rifampin, pyrazinamide, and ethambutol. On regular follow up, the sinus healed fully and patient had good range of motion without pain and fracture healed.

DISCUSSION

Musculoskeletal tuberculosis can be difficult to diagnose as only about one third of patients have respiratory symptoms. Tuberculosis infection in an open wound is a rare but well known condition. Cases had been reported in literature. The commonest site is the dorsum of hand, fingers. The earliest case reported is by Tscherning in 1888, from a servant who acquired tubercular infection after wounding herself from a sputum cup of a tubercular patient. Tuberculous arthritis is mainly caused by haematogenous spread of pulmonary tuberculosis or traumatic cases.[23] It often occurs at weight-bearing joints, most commonly the spine, followed by hip and knee joints.[6] Joint swelling and pain exacerbated by activity are the most common manifestation.[4] Tuberculosis arthritis is characteristically monoarticular and rarely involves more than one joint.[7] Its development is slow, with sporadic joint pain during the early stages. Pain during activity leads to limited joint movement and even joint contracture or deformation. Because the disease is often asymptomatic or has no specific symptoms in the early stages, the time between the appearance of symptoms and diagnosis averages 16 months.[8] Loose bodies are fragments of bone and/or cartilage that freely float in the joint space. Fibrinous loose bodies result from bleeding within the joint or from the death of the synovial membrane of joints. Tuberculosis diagnosis in this case was established on histopathological examination and AFB staining of the suspected loose body in the patient's joint while surgical debridement and implant removal. Arthritis following injury may be due to following reasons: (a) a localizing action, i.e., a new tubercular focus develops at the seat of the trauma, must be looked upon as extremely rare, (b) amobilizing action, which means the injury causes a bursting of a quiescent lesion, with consequent dissemination of tubercle bacilli as an action of aggravation, i.e., lighting up of a quiescent focus (e.g., in a joint). 95 per cent of cases come into this category. But the patient in this case report had a history of trauma with open injury, who had no history suggestive of previous tuberculosis, his immunological status was also found normal.

Trauma by increasing the vascularity may help in localizing the lesion. Symptoms of Tuberculous arthritis are both unclear and obscure, which are clinically manifested as local swelling and chronic pain of a single joint accompanied by gradually decreased range of motion. Joint swelling and pain exacerbated by activity are the most common manifestation. According to him interval which may elapse between the injury and the development of symptoms of tuberculosis varies between two weeks and five months in most forms of tuberculosis in cases acquired from open injuries. Tubercular arthritis is important to recognize the less common presentations of this condition to enable early diagnosis and successful treatment. Because of the indolent disease process and the subtle nature of symptoms, diagnostic evaluations are often not undertaken until the disease has progressed. In early stages the symptoms can mislead to septic arthritis, rheumatoid arthritis or due to trauma. Radiological features are non-specific and so a high index of suspicion is required. In patients with risk factors, or any suspicion of tuberculosis, a biopsy should be performed to make the diagnosis and initiate treatment.

In this case 30 year old man presented with pain, swelling and deformity in right elbow. Compound intercondylar fracture in right humerus with communited right olecranon was seen in plain radiography. ORIF was performed. On the 5th post-surgical day patient presented with drainage from surgical wound for which debridement was done and sinus healed. After 6 months the patient returned with recurrence of discharging sinus. Some seed like bodies were removed and sent for histopathological examination. Histological examination showed circumscribed fibrinous loose bodies. Acid Fast Bacilli staining (Ziehl-Neelsen Staining) was done and found positive.

A gold standard for the diagnosis of tuberculous arthritis is to identify M. tuberculosis. On AFB staining of the synovial fluid, positive findings are observed in 20-25% of samples. A culture test of the synovial fluid can identify tuberculosis in 60-80% of samples. A tissue biopsy of synovial membrane can produce more apparent results. Also, in the current case, a diagnosis of tuberculous arthritis was made based on the post-operative biopsy of the synovial membrane and AFB staining.

Early diagnosis of tubercular arthritis is difficult because of insidious onset, indolent process and mild or non specific local or systemic symptoms. So, confirmed diagnosis and effective treatment for tubercular arthritis are delayed until the disease progress to an advanced stage. In the early stage of diseases, tuberculous arthritis may be easily mistaken for trauma or rheumatoid arthritis and septic arthritis. Surgical debridement and strict adherence to antituberculosis treatment tend to yield a satisfactory functional outcome. With early diagnosis and treatment, approximately 90% to 95% of patients with tuberculous arthritis can achieve healing with near normal function.[9]

Loose bodies are fragments of bone or cartilage that freely float in the joint space, classified as: Fibrinous, cartilaginous, and osteocartilaginous.[1011] Fibrinous loose bodies resembling rice grains, melon seeds or irregular in shape, result from bleeding within the joint or from the death of the synovial membrane caused by tuberculosis, osteoarthritis, and rheumatoid arthritis. Histologically homogenous and concentrically laminated masses of fibrin are seen. They result from the coagulation of fibrin-forming elements in the exudates or of fibrinous degeneration of the surface layer of the diseased synovial membrane. However formed, their shape is the result of mechanical influences, and especially of the movement of the joint. Cartilaginous loose bodies are fragments of cartilage, histologically composed mainly of hyaline, due to trauma and osteoarthritis. Osteocartilaginous loose bodies are fragments of cartilage and bone caused by fractures, osteochondritis dissecans, osteoarthritis, and synovial chondromatosis.[1011]

The radiologic findings of tuberculous arthritis are non-specific in the early stage. As shown in the current case, they can be easily overlooked. After several months following the onset of symptoms, there can be symptoms such as periarticular osteopenia and soft tissue swelling. On further progression of the disease, there can also be such findings as bone erosion and joint space narrowing.[12]

In this regard the etiology of loose bodies was trauma and not already existing tuberculosis. The subject of loose bodies in joint is not only of considerable practical importance but it constitutes a pathological problem of great interest. The surgeon has to be aware of the significance of loose bodies when performing routine excision of joint swelling.

CONCLUSION

The indolent course of disease and the presence of non-specific symptoms render early recognition of this disease difficult. The diagnosis and treatment of articular TB are surgical debridement and strict adherence to anti-tuberculosis chemotherapy tends to yield a satisfactory functional outcome. Also the importance of bacteriological and histological investigations of any material in a joint for establishing the specific diagnosis is emphasized.