Franco, John

BackgroundMedial meniscal extrusion (MME) has been correlated with medial meniscal injury and progression of medial knee osteoarthritis (OA).ObjectiveTo examine the difference in MME between non‐weight‐bearing (supine) and weight‐bearing (standing) positions in patients with and without medial knee OA. Determine the correlation between body mass index (BMI), Kellgren‐Lawrence (KL) grade, Knee Osteoarthritis Outcome Score (KOOS), and MME.DesignProspective.SettingTertiary institution PM&R Department.ParticipantsForty five participants (29 female, 16 male), 24 with healthy knees and 21 with OA.Methods or InterventionsA single physician sonographer measured supine and standing MME with ultrasound (US) on each participant. The physician was blinded to all measurements. BMI was recorded on all participants. KL grades and KOOS questionnaires were obtained for the OA group.Main Outcome MeasuresMME in supine and standing positions, change in MME from supine to standing, BMI, KL grade, and KOOS subscale scores.ResultsMME increased .52 mm from supine to standing (P < .001). MME was greater in the OA group in both the supine (P = .002) and standing (P < .001) positions. Increasing BMI was moderately correlated with increasing MME (supine P = .001, standing <.001). Increasing age was correlated with increasing MME (supine P = .012, standing P = .002). Increasing KL grade (from 1 to 4) was correlated with increasing MME (supine P = .015, standing = .006). There was a small‐to‐moderate correlation between KOOS activities of daily living (ADL) subscale score and change in MME from supine to standing (P = .035). The change in MME from supine to standing positions had a small‐to‐moderate correlation (P = .035) with KOOS ADL subscale score alone but did not correlate with any of the other KOOS subscale scores or KOOS total scores. Receiver operating characteristic curve analysis suggested a standing MME value of 4.2 mm provides a positive likelihood ratio of 6.02 for knee OA.ConclusionsMME is greater in those with OA and with weight‐bearing. MME correlates with BMI, age, KL grade, and the KOOS ADL subscale score. Finally, standing MME of 4.2 mm yielded a higher positive likelihood ratio to differentiate between healthy knees and those with medial compartment OA than the previously reported value of 3.0 mm.

ABSTRACT Purpose This study aimed to evaluate the incidence and characteristics of exertional rhabdomyolysis (ER) in a population-based cohort. Methods A retrospective cohort study was performed in Olmsted County, Minnesota, from 2003 to 2015. Incident ER cases were ascertained through the Rochester Epidemiology Project medical record linkage system through electronic searches of the International Classification of Diseases, Ninth Revision , codes and clinical note text. Population incidence rate was calculated using the corresponding Rochester Epidemiology Project census populations specific to calendar year and sex. Descriptive statistics were used. Results Of the 430 patients, 431 cases met the inclusion criteria for rhabdomyolysis; 4.9% of cases ( n = 20; males n = 18; Caucasian n = 17) were ER, with one recurrence. There were no deaths secondary to ER. The age- and sex-adjusted incidence rate of ER was 1.06 ± 0.24 (95% confidence interval = 0.59–1.52) per 100,000 person-years. Endurance activity ( n = 7), manual labor ( n = 5), and weight lifting ( n = 4) were common causes. Complications included kidney injury ( n = 5), mild electrolyte abnormalities ( n = 10), elevated transaminases ( n = 12), and minor electrocardiographic abnormalities ( n = 4). A majority of patients were hospitalized ( n = 16) for a median of 2 d, had mild abnormalities in renal and liver function and electrolytes, and were discharged without sequelae. Conclusion ER in the civilian population occurs at a much lower incidence than the military population. The most common causes were endurance exercise, manual labor, and weight lifting. The majority of cases were treated conservatively with intravenous fluid resuscitation during a brief hospital stay, and all were discharged without sequela. Only one case of recurrence occurred in this cohort, indicating the recurrence rate was low.

BackgroundUltrasound has become a useful instrument in evaluating musculoskeletal pathology. Recent studies suggest that ultrasound imaging of weight‐bearing menisci may enhance the assessment of knee pathology, such as osteoarthritis (OA) and meniscal injuries.ObjectiveThe primary aim of this study was to determine the intrarater and interrater reliability of ultrasound measurements of medial meniscal extrusion (MME) after a brief training session.DesignProspective reliability study.SettingPhysical medicine and rehabilitation (PM&R) department within a tertiary care institution.ParticipantsForty‐five participants (29 female, 16 male) were recruited to serve as models, 24 of whom had healthy knees and 21 of whom had radiographically confirmed medial compartment knee OA. Three physician sonographers (1 = experienced, 1 = sports medicine fellow, 1 = post‐graduate year [PGY]‐4 PM&R resident) were recruited to serve as operators.Methods or InterventionsOperators received a brief training session on identifying and measuring MME. All operators measured bilateral MME in each model in the standing and supine positions on two separate days. Operators were blinded to all measurements.Main Outcome MeasurementsPrimary outcomes were inter‐ and intrarater intraclass correlation coefficients (ICCs) of MME measurements among operators with different levels of ultrasound experience.ResultsSupine MME intrarater reliability ICCs were 0.927, 0.885, and 0.780 for the experienced physician, sports medicine fellow, and PGY‐4 operators, respectively. Standing MME intrarater reliability ICCs were 0.941, 0.902, and 0.824 for the experienced physician, sports medicine fellow, and PGY‐4 operators, respectively. Interrater reliability ICCs were 0.896 and 0.842 for supine and standing measurements, respectively. There was a statistically significant increase in intrarater reliability with experience between the PGY‐4 resident and experienced physician operators.ConclusionsOperators with different levels of ultrasound experience demonstrated good MME measurement intra‐ and interrater reliabilities in both supine and standing positions.