A study on evaluation of knee osteoarthritis with MRI and comparing it with CT scan, high resolution USG and conventional radiography

Background: Knee osteo-arthritis is widely prevalent in the elderly population in our society and associated with significant morbidity and poor quality of life. Early diagnosis of the condition can enable timely and proper care for the patients. Magnetic Resonance Imaging, CT Scan, Ultrasonography and plain radiography are the different modalities of imaging that are commonly used for detection and diagnosis of knee osteo-arthritis. Aims and Objectives: To find out the early osteoarthritic changes of knee by Magnetic Resonance Imaging and compare those findings with conventional radiography, high frequency USG and CT scan findings. Materials and Methods: Patients suffering from knee osteoarthritis (OA) as per American College of Rheumatology guideline criteria (n=56) underwent imaging of the knee using plain radiography, ultrasonography, CT scan and MRI. The imaging findings studied in the patients were joint space narrowing (JSN), meniscal abnormality, Baker’s cyst, cruciate ligament abnormality, knee effusion, subchondral cyst, and loose bodies. A comparison between radiography, CT scan and USG was done for the imaging findings with MRI as the reference standard. Z-test of proportionality was used to find statistically significant difference for the three imaging modalities. A P<0.05 was deemed statistically significant. Results: The mean age of the patients was 61 years (38 males). The tibiofemoral compartment was most commonly affected. CT scan was more sensitive than radiography in detecting sub-chondral cyst (P=0.018) and loose bodies (P=0.004). USG and MRI were equally sensitive in detecting knee effusion (P=0.22) and synovial thickening (P=0.10). CT scan and MRI were equally sensitive in detecting subchondral cyst (P=1.00) and loose bodies (P=0.22). Conclusion: While CT imaging was more sensitive for detection of subchondral cysts and loose bodies than conventional radiography, it was as sensitive as MRI in detecting these findings in the study group. Additional study is warranted to assess diagnostic performance of CT scan and MRI in the diagnosis and progression of knee OA.

Clinical and Radiographic Differentiation of Pediatric Patellar Sleeve Fractures and Other Inferior Pole Pathologies (165)

Objectives: Inferior pole patellar sleeve fractures (PSF) are rare injuries that occur in skeletally immature patients with sparse literature on the diagnosis, management, and outcomes of this injury. Diagnosis of PSF can be difficult based on radiographs alone, as only a small bony fragment is often seen. Consequently, PSFs may be missed or falsely diagnosed as an inferior pole fracture (IPF) or Sinding-Larson-Johansson syndrome (SLJS) possibly leading to improper treatment and poor outcomes (Figure 1). The objective of this study was to evaluate and compare clinical and radiographic features of patients with PSF, IPF and SLJS to help improve diagnostic accuracy. Methods: This was a retrospective review of skeletally immature patients diagnosed with inferior pole patellar pathology between 2011-2019 at a single urban academic center. Patients were identified using both International Classification of Diseases 9th and 10th edition (ICD-9 and ICD-10) codes and Current Procedural Terminology (CPT) codes. Data from medical records (demographics, injury mechanism and physical exam) and lateral knee radiographs (fragment size, fragment displacement, number of fragments, Insall-Salvati, Caton-Deschamps, pre-patellar effusion, intra-articular effusion) was collected. ANOVA, Student’s t-test and Fisher’s exact test were used for comparisons between the three groups. Statistical significance was determined at p<0.05. This study was approved by our institutional review board. Results: A total of 125 patients were included: 82% male, average age 10.7 years (SD 2), 16 PSF, 51 IPF, 58 SLJS patients. There were no significant differences in patient demographics between the three groups (Table 1). Only 24% of SLJS patients presented with acute trauma compared to 100% of the PSF and IPF patients. Fewer PSF patients had an intact straight leg raise (37.5%) compared to IPF (94.1%) and SLJS (98.3%) (p<0.001). SLJS patients were less likely to present with knee swelling (41.4%) compared to PSF (93.8%) and IPF (94.1%) (p<0.001) . Knee effusion was more frequently seen in PSF (81.2%) compared to IPF (37.3%) and SLJS (3.4%) (p<0.001). More patients with SLJS were able to bear weight (87.9%) compared to IPF (11.8%) and PSF (0%) (p<0.001) (Table 2). Radiographically, compared to those with IFP and SLJS, patients with PSFs had increased mean prepatellar swelling (6.1 and 6.5 versus 12.9mm, p<0.001), intra-articular effusion (6.1 and 4.9 versus 9.2mm, p<0.001), maximum fragment size (26 and 17.7 versus 45.3mm, p<0.001) and maximum fragment displacement (1.24 and 1.45 versus 13.30mm, p<0.003) respectively. Compared to SLJS, PSF and IPF patients had higher patella alta with mean Insall-Salvati ratios > 1.2 (Table 3). Conclusions: Differences in clinical features such as straight leg raise, knee swelling, knee effusion, ability to bear weight and radiographic features such as prepatellar swelling, intra-articular effusion, fragment displacement/size/shape/location can all be helpful in improving the accuracy of diagnosing inferior pole injuries in pediatric patients.

The Updated Role of Ultrasound in the Assessment of Knee Osteoarthritis

Background Osteoarthritis (OA) of the knee is the most common form of knee arthritis and a leading cause of chronic disability. Objective The aim of the current study is to reassess the utility of the updated ultrasound in the patients with knee osteoarthritis and outline its clinical application. Patients and Methods The studied group included 36 patient 23females and 13 males with their ages ranged between 39 and 58 years (average age 44 years). The patients were referred to US examination fulfilling the ACR clinical criteria for knee OA after orthopedic and /or rheumatologist consultation. The study was performed in Radiodiagnosis department Ain Shams University Hospitals (20 patients ) and at one private center (16 patients). Results There was a discrepancy between the results obtained by clinical examination and those demonstrated by ultrasonography. Clinical examination detected 22 (61.1%) of our cases. Prevalence of US findings in our cases were femoral articular degeneration in 28 (77.7%) patients, Tibiofemoral osteophytes were seen in 26 patients (72.2%), knee effusion in 22 patients (61.1%),meniscal extrusion in 22 patients (61.1%) meniscal degeneration in 17 patients (47.2%) and synovial hypertrophy in 15patients (41.6%). Baker’s cysts were demonstrated in 14patients (38.8%) while pes anserine syndrome was demonstrated in 4 cases. Meniscal degeneration and meniscal extrusion were correlated significantly with femoral cartilage degeneration (P&lt;.001). Although knee effusion did not correlate with advanced knee effusion did significantly (P &gt; 0.05). Baker's cysts is statistically related to the presence and severity of mensical changes and also related to the degree of femoral articular cartilage degeneration. Conclusion US is a valuable technique that can assess soft tissue structures within the knee and their involvement in the osteoarthritic process .US enables in guiding and monitoring therapy through detection of knee structural damage.

1664 A rare case of Stenotrophomas maltophilia affecting an ACL Endobutton: A Case Report and Review of the literature

Background Stenotrophomas maltophilia (SM) is a ubiquitous opportunistic gram-negative bacillus known to cause hospital acquired infections, commonly in immunosuppressed individuals. However, occurrence of this microorganism is rarely reported in the musculoskeletal system. We report a case of a young healthy man with recurrent knee swelling caused by SM. This organism has been reported to form biofilms over orthopaedic implants, with increased resistance to antibiotic therapy, making it difficult to eradicate once established. Case Report A 34-year-old man with psoriasis and asthma presented with right knee swelling and pain, and no history of preceding trauma or fever. He has a past surgical history of anterior cruciate ligament tear and underwent reconstruction with an endobutton two years prior, and a lateral meniscal repair treated in the previous year. At presentation, he was apyrexial and was noted to have a moderate right knee effusion. Initial radiographic imaging identified a large joint effusion with no obvious evidence of bone destruction, laboratory studies also showed a raised white cell count of 11.4 *10^9/L, C-reactive protein of 54mg/L and aspiration cultures were negative. He subsequently underwent numerous washouts, and removal of endobutton with open synovial biopsy which showed SM. The organism was sensitive to cotrimoxazole. The patient had appropriate antibiotics with resolution of symptoms, however he still presented with recurrence. Conclusions The persistence of SM despite intervention makes it difficult to treat. Although a rare organism, surgeons should consider it as a differential in recurring knee effusion with orthopaedic implants, and institute early and appropriate management for best outcomes.

High incidence of acute self-reported sleep disturbances in patients following arthroscopic-assisted knee surgery

ObjectivesTo evaluate the self-reported incidence of sleep disturbances, defined as ≤7 hours of sleep per 24-hour period, in patients undergoing arthroscopic-assisted knee surgery.MethodsPatients who underwent arthroscopic knee surgery over the course of a 4-month period were prospectively included. Patients were excluded if a history of insomnia or other sleep altering medical history was reported. Self-reported sleep metrics included average number of hours of sleep per night, average number of awakenings during sleep per night, perceived quality of sleep, average pain level during sleep and number of hours of physical activity/therapy per week. Data were collected at weeks 1, 3, and 6 postoperatively. Joint circumference was measured on postoperative day 1 and served as an indicator of a knee effusion. Paired t-tests were used to compare preoperative to postoperative hours of sleep. Simple and multiple linear regression were used to evaluate relationships between surgical variables and postoperative sleep metrics.ResultsThere were 123 patients who underwent arthroscopic knee surgery during the prospective enrolment period; 83 patients were included in the final analysis. The overall incidence of preoperative sleep disturbances was 20% (n=17). The overall incidence of self-reported postoperative sleep disturbances was 99%, 96% and 90% at weeks 1, 3 and 6, respectively. The average number of hours slept was significantly reduced at 1, 3 and 6 weeks postoperatively compared with the preinjury state (p<0.001). Knee joint circumference had a significantly negative correlation with average number of hours of sleep in the first 6 weeks postoperatively (R=−0.704; p=0.001). Surgical variables including severity of surgery, weekly postoperative pain level and weekly hours of postoperative physical therapy were not significant independent predictors of acute postoperative sleep disturbances (p>0.05).ConclusionSleep disturbances were commonly reported in patients following arthroscopic knee surgery without correction of sleep metrics by 6 weeks postoperatively. The majority of sleep disturbances in this cohort correlated with an increased knee effusion. A multidisciplinary team approach is recommended to counsel patients regarding the potential for and problems with acute sleep disturbances following arthroscopic knee surgery.Level of evidence: 3.

Posttraumatic Chylous Knee Effusion

This is a very rare case of posttraumatic chylous joint effusion that has been described only a few times before in the literature.1,2,3,4,5 A 64-year-old White woman presented at the outpatient clinic with persistent knee pain for 5 weeks that she related to a fall.

Spontaneous Knee Effusion in an Adolescent Soccer Player

A 13-year-old female recreational soccer player presented with spontaneous left knee effusion approximately 2 weeks after the start of soccer season. Radiographic imaging was negative, and a complete blood count identified an increase in inflammatory markers. Additional two-tier testing confirmed a Lyme disease diagnosis, which was unusual for an athlete residing in the southeast region of the United States. The presentation of knee effusion, and subsequently Lyme arthritis, is a common clinical manifestation of late-stage Lyme disease. Early recognition of this infection and prompt treatment by a variety of specialists reduce the severity or chronicity of symptoms.