Important Considerations When Determining the Cost-effectiveness of Viscosupplements in the Treatment of Knee Osteoarthritis: Letter to the Editor regarding Rosen, J., Sancheti, P., Fierlinger, A. et al. Adv Ther (2016) 33: 998. doi:10.1007/s12325-016-0331-8

Ultrasound Assessment of Weight-Bearing and Non-Weight-Bearing Meniscal Extrusion: A Reliability Study

BACKGROUND

Ultrasound 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.

OBJECTIVE

The 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.

DESIGN

Prospective reliability study.

SETTING

Physical medicine and rehabilitation (PM&R) department within a tertiary care institution.

PARTICIPANTS

Forty-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 INTERVENTIONS

Operators 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 MEASUREMENTS

Primary outcomes were inter- and intrarater intraclass correlation coefficients (ICCs) of MME measurements among operators with different levels of ultrasound experience.

RESULTS

Supine 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.

CONCLUSIONS

Operators with different levels of ultrasound experience demonstrated good MME measurement intra- and interrater reliabilities in both supine and standing positions.

Comparison of Low-, Moderate-, and High-Molecular-Weight Hyaluronic Acid Injections in Delaying Time to Knee Surgery

BACKGROUND

We compared the effectiveness of low-molecular-weight (MW) hyaluronic acid (HA) injections (LMWHA), moderate-MW HA injections (MMWHA), and high-MW HA injections (HMWHA) for prevention or delay of knee surgery in patients with knee osteoarthritis.

METHODS

An observational cohort study using LifeLink Plus claims (2006-2015) was used. The primary outcome measure of the study included all surgical interventions of the knee. The secondary outcome measures were the following: (1) unicompartmental knee arthroplasty or total knee arthroplasty and (2) total knee arthroplasty only. A high-dimensional propensity score (hdPS) using 1:1 matching was used to adjust for confounding. The likelihood of each outcome was assessed using Cox proportional hazard models.

RESULTS

A cohort of 30,417 incident HA users with knee osteoarthritis met our inclusion-exclusion criteria. There was no difference in the likelihood of composite surgical events between LMWHA users (hazard ratio, 0.939; 95% confidence interval, 0.870-1.013) and MMWHA users (hazard ratio, 1.032; 95% confidence interval, 0.952-1.119) when compared with HMWHA users in a matched hdPS analysis. However, a significantly lower likelihood for all outcome measures was demonstrated in LMWHA and MMWHA users compared with HMWHA users when hdPS was not used.

CONCLUSION

There was no significant difference in the likelihood of surgical interventions between LMWHA, MMWHA, and HMWHA users after accounting for empirically derived confounders.