Pediatric unilateral knee swelling: a case report of a complicated differential diagnosis and often overlooked cause

Lyme disease is the most common vector-borne illness in the United States. However, Lyme arthritis is a diagnosis that is often missed, even in children, who are the population with the highest incidence of Lyme disease. Lyme arthritis, which presents in the later stage of Borrelia burgdorferi infection, needs to be recognized and managed promptly, especially in endemic areas or when exposure to ticks is known. We present a case of a 3-year-old female presenting to the emergency department with a history of limping for 2 weeks. The mother of the child recognized a tick bite. However, the child was not taken to seek care expeditiously, because she had not developed any rashes. Test results demonstrated that the patient was IgG positive and IgM negative for Lyme disease, with Western blot confirming the diagnosis of Lyme arthritis. Most patients presenting with Lyme arthritis do not recall having a tick bite, making it difficult to differentiate it from other pediatric conditions. When this diagnosis is missed, it can result in long-term morbidity, which is generally refractory to intravenous antibiotic therapy, oftentimes requiring synovectomy. Hence, this underscores the importance of the consideration of Lyme arthritis as a differential diagnosis in patients presenting with joint effusion.

Remnants-preserving ACL reconstruction using direct tendinous graft fixation: a new rat model

Background Anterior cruciate ligament (ACL) repair techniques are new emerging strategies prevailing, in selected cases, over standard reconstruction of the ACL with excision of its remnants. Mid-substance ACL tears represent a challenge for ACL repair techniques, and remnants-preserving ACL reconstruction (rp-ACLR) using an autograft remains the recommended treatment in this situation. However, morbidity associated with the autograft harvesting prompts the need for alternative surgical strategies based on the use of synthetic scaffolds. Relevant small animal models of mid-substance tears with ACL remnants preservation and reconstruction are necessary to establish the preliminary proof of concept of these new strategies. Methods A rat model of rp-ACLR using a tendinous autograft after complete mid-substance ACL transection was established. Twelve weeks following surgery, clinical outcomes and knee joints were assessed through visual gait analysis, Lachman tests, thigh perimeter measurements, magnetic resonance imaging, micro-computed tomography, and histology, to evaluate the morbidity of the procedure, accuracy of bone tunnel positioning, ACL remnants fate, osteoarthritis, and autograft bony integration. Results were compared with those obtained with isolated ACL transection without reconstruction and to right non-operated knees. Results and discussion Most operated animals were weight-bearing the day following surgery, and no adverse inflammatory reaction has been observed for the whole duration of the study. Autograft fixation with cortical screws provided effective graft anchorage until sacrifice. Healing of the transected ACL was not observed in the animals in which no graft reconstruction was performed. rp-ACLR was associated with a reduced degeneration of the ACL remnants (p = 0.004) and cartilages (p = 0.0437). Joint effusion and synovitis were significantly lower in the reconstructed group compared to the transected ACL group (p = 0.004). Most of the bone tunnel apertures were anatomically positioned in the coronal and/or sagittal plane. The most deviated bone tunnel apertures were the tibial ones, located in median less than 1 mm posteriorly to anatomical ACL footprint center. Conclusion This study presents a cost-effective, new relevant and objective rat model associated with low morbidity for the preliminary study of bio-implantable materials designed for remnants-preserving ACL surgery after mid-substance ACL tear.

Conservative Rehabilitation of Partial Anterior Cruciate Ligament Tear - A Case Report

The anterior cruciate ligament is one of the most important ligaments in the knee joint (ACL). The ACL is necessary for appropriate knee joint mobility and mechanics. When the ACL is torn, patients may experience issues with their knee's function, as well as instability and the sensation of 'falling away' while walking. The anterior cruciate ligament acts as a main restraint on tibia-to-femur translation (anterior shear). Depending on the angle of knee flexion, this function is allocated to either anteromedial or posterolateral bundle. When the knee is fully extended, the posterolateral bundle is tense; however, when the knee flexes, the posterolateral bundle loosens and the anteromedial bundle tightens. We report the case of a 32-year-old man who twisted his leg while jogging, resulting in a partial thickness ACL rupture and mild joint effusion along the periarticular surface of the right knee, as revealed by radiological symptoms and MRI.Conservative rehabilitation in a patient aged 32 year shows good results and so the surgery was not performed. Initially 10 weeks protocol was managed in hospital under the guidance of a therapist including strengthening, stretching and conditioning of lower limb muscles, later on as pain reduced and patient achieved functional pain free range 12 week protocol was further set for home program.

Detecting low blood concentrations in joints using T1 and T2 mapping at 1.5, 3, and 7 T: an in vitro study

Background Intra-articular blood causes irreversible joint damage, whilst clinical differentiation between haemorrhagic joint effusion and other effusions can be challenging. An accurate non-invasive method for the detection of joint bleeds is lacking. The aims of this phantom study were to investigate whether magnetic resonance imaging (MRI) T1 and T2 mapping allows for differentiation between simple and haemorrhagic joint effusion and to determine the lowest blood concentration that can be detected. Methods Solutions of synovial fluid with blood concentrations ranging from 0 to 100% were scanned at 1.5, 3, and 7 T. T1 maps were generated with an inversion recovery technique and T2 maps from multi spin-echo sequences. In both cases, the scan acquisition times were below 5 min. Regions of interest were manually drawn by two observers in the obtained T1 and T2 maps for each sample. The lowest detectable blood concentration was determined for all field strengths. Results At all field strengths, T1 and T2 relaxation times decreased with higher blood concentrations. The lowest detectable blood concentrations using T1 mapping were 10% at 1.5 T, 25% at 3 T, and 50% at 7 T. For T2 mapping, the detection limits were 50%, 5%, and 25%, respectively. Conclusions T1 and T2 mapping can detect different blood concentrations in synovial fluid in vitro at clinical field strengths. Especially, T2 measurements at 3 T showed to be highly sensitive. Short acquisition times would make these methods suitable for clinical use and therefore might be promising tools for accurate discrimination between simple and haemorrhagic joint effusion in vivo.

MALIGNANCY MASQUERADING AS JOINT INFECTION- A CASE REPORT

ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) is the most common malignancy in children. It accounts for 25% of all childhood cancers and approximately 75% of all cases of childhood leukemia. ALL presents usually with fever, lassitude, pallor, bone pains+/- bleeds. Here, we present a case of a child presenting with prolonged fever and swelling and pain in joints. Child was initially diagnosed as one hematological disorder and presented with joint effusion within a week.

P035 Hip involvement in Tunisian Juvenile Idiopathic Arthritis patients

Background Juvenile idiopathic arthritis (JIA) is characterized by a widely variable clinical course and outcome. If uncontrolled, joint damage may occur. In this context, coxitis is a feared complication. The aim of our study was to determine the prevalence and patterns of hip involvement in Tunisian JIA patients. Methods A retrospective study including children with JIA according to the International League of Associations for Rheumatology (ILAR)) was conducted between 2012and 2021. Sociodemographic data as well as disease characteristics were collected. Laboratory markers including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded. Hip involvement was assessed clinical exam and imaging (standard radiograph, ultrasound or magnetic resonance imaging (MRI)). We compared these parameters between the two groups: G1: presence of coxitis and G2: absence of coxitis. Results The study included 40 patients with a male predominance: sex ratio was 1.6. The mean age was 11.1 years-old [3–16]. The mean age at onset of the disease was 18.1 years old [8–30]. The distribution of the different subsets was as follows: polyarticular with rheumatoid factor (n = 1), polyarticular without rheumatoid factor (n = 2), enthesitis-related arthritis (n = 29), oligoarthritis (n = 7), psoriatic arthritis (n = 1). Extra-articular manifestations were found in 21.2% of cases: ocular (n = 4), pulmonary (n = 2) and cardiovascular (n = 1). The mean ESR and CRP was 30.9 mm/h [2–90] and 15.8 mg/l [1–70] respectively. A high ESR or CRP were found in 67% of cases. Hip involvement concerned 70% of the patients and was bilateral in 67.9% of them. Hip radiographs were normal in 50% of cases. Ultrasound was performed in 9 patients and revealed a positive Doppler synovitis (n = 2), a negative Doppler synovitis (n = 7) and joint effusion (n = 2). MRI was performed in 20% of cases and revealed synovitis (67%) and joint effusion (33%). Overall, 79.3% of patients had medical treatment combining NSAIDs and rehabilitation, 39% of the patients had had local infiltration with Hexatrione and only two patients had hip replacement. Hip involvement was not correlated with age at onset (P = 0.2), subtype (P = 0.8), sex (P = 0.7), extraarticular manifestations (P = 0.4). Similarly, there was no correlation between the presence of coxitis and ESR (P = 0.07) as well as CRP (P = 0.5). Conclusion Our study showed that hip involvement is frequent among Tunisian patients with JIA. Although not correlated with disease characteristics, hip involvement should be assessed frequently and carefully.

P077 Ultrasound features of a traumatic hip pain in paediatric population

Background Atraumatic hip pain in children is a serious condition that may require urgent investigations. Conventional radiographs are often normal in early stage of the diseases. However, further imaging techniques such as hip ultrasonography (US) are needed. The main objective of this study is to describe Hip ultrasound findings in patients with atraumatic hip pain. Methods We conduct a retrospective monocentric study. Children with atraumatic hip pain and undergoing joint ultrasound were included. Sociodemographic, clinical and biological characteristics were collected. The data were analyzed using the SPSS statistical package. Results: Thirty patients (21 boys and 9 girls) were enrolled. The male to female sex ratio was 2.3. Mean age at disease onset was 9.1 ± 4.6 [1.3–16]. Median diagnosis delay from symptoms onset was 1.2 months [0.2–48]. Chief complaints were as following: 80% of inflammatory hip pain (n = 24), 20% of mechanical hip pain (n = 6) 76.7% of limping (n = 23), 23.3% of functional impotence (n = 7) and 23.3% of fever (n = 7). Physical examination noted a pain on passive joint mobilization and restriction of hip movement in 90% (n = 27) and 54% (n = 18) of cases respectively. A biologic inflammatory syndrome was found in 66.6% of cases (n = 20). Median ESR and CRP were 30 mm/h [2–101] and 4.5 mg/l [1–38] respectively. Hip X-ray was abnormal in 46.6% (n = 14) of cases. All patients had hip ultrasound. US findings were as following: 80% (n = 24) of joint effusion, 50% (n = 15) of synovial thickening, 36.7% (n = 11) of synovitis and 23.3% (n = 7) of positive power Doppler signal. Hip Ultrasound was normal in 13.3% (n = 4) of cases. Causes of hip pain were in decreasing order of frequency: septic arthritis (n = 10), juvenile idiopathic arthritis (n = 10), transient synovitis (n = 7), osteoid osteoma (n = 2) and osteosarcoma (n = 1). Conclusion Hip Ultrasonography is a noninvasive and useful screening technique for the management of atraumatic hip pain in children. Though, imaging features are often various and nonspecific. Radiologists should be more familiar with sonographic anatomy of infant hip.

CONSERVATIVE REHABILITATION OF PARTIAL ANTERIOR CRUCIATE LIGAMENT TEAR FOR BETTER FUNCTIONAL OUTCOME

To stabilize the knee joint, the anterior cruciate ligament (ACL) is one of the important ligaments. For normal movement and mechanics of the knee joint, ACL is important. If the ACL is torn, people notice problems in stability function of knee joint and there the feeling of ‘giving away’ while weight bearing. The function of anterior cruciate ligament is to restrain translation of the tibia on the femur. However, this role is divided by either anteromedial or the posterolateral bundle, depending on the knee flexion angle. The posterolateral bundle is stretched when the knee is close to full extension; as the knee flexes, the posterolateral bundle loosens and the anteromedial bundle becomes tight. In this report, a 32-year-old male who had a history of twisting of the leg while jogging, started by him since 40 days, lead to partial thickness tear of ACL, minimal joint effusion along the periarticular surface of the right knee and was diagnosed by radiological findings and MRI. As patient was not ready for surgery, he decided to opt for physiotherapy management. The aim of this study is to study effects on functional outcomes after physiotherapy rehabilitation of ACL injury without any invasive procedure.