National Registry Data Analysis on a Unique Highly-Crosslinked Polyethylene for Total Hip Arthroplasty.

Background: Several types of highly-crosslinked polyethylene with different manufacturing processes and mechanical properties are commercially available, including HIGHCROSS (Medacta). The aim of this registry study is to ascertain the long-term safety of the HIGHCROSS liners in total hip arthroplasty and compare the revision rates with its contemporaries using real-world data to establish their safety and generalizability when used by multiple surgeons. Methods: The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Swiss National Joint Registry (SIRIS) were selected for the large number of users of Medacta implants and the availability of long-term results. Three reports from SIRIS and 4 reports from AOANJRR were examined to establish the overall and Kaplan-Meier (KM) cumulative revision rate. Results: According to SIRIS, the HIGHCROSS liner was the most commonly used bearing surface with Medacta stems with overall revision rates for wear/osteolysis at 9.7 years of 0.04% and 0.03%, respectively, for AMIStem and Quadra. Based on AOANJRR, the KM cumulative revision rate for any reason of Medacta stems with HIGHCROSS liners was lower than that with ceramic liners at 3 years for MasterLoc and at 10 years for Quadra. The KM cumulative revision rate for any reasons of Medacta cementless cups with HIGHCROSS liners at 12 years was lower than the comparator made of all other implants and tribological couplings (1.6% vs 2.1%). Conclusions: This real-world data proves that long-term HIGHCROSS survival rates are comparable to other modern bearing surfaces.

Measurement consistency of dynamic stretching muscle stiffness evaluated using shear wave elastography: comparison among different stretched levels and ROI sizes.

AIM: To investigate the reliability of quantitative analysis of dynamic stretching muscle stiffness using shear wave elas-tography (SWE), and to evaluate the influence of stretched levels and region of interest (ROI) sizes on the repeatability of SWE measurements. MATERIALS AND METHODS: SWE videos of the gastrocnemius medius were collected during ankle movement from plantar flexion (PF) 40° to dorsiflexion (DF) 30°. Shear wave imageswere collected of ankle angles at PF 25°, 0°, DF 15°, and DF 30°, representing the slack status, mildly stretched level, moderately stretched level, and maximal stretched level of the gastrocnemius medius, respectively. ROI circles with diameters of 2 mm, 5 mm, and 8 mm were applied to measure the shear modulus. Intra-observer, and inter-observer repeatability of the measurements were compared among different stretched levels and ROI sizes. RESULTS: Twenty-one healthy volunteers were enrolled. Muscle stiffness increased as the ankle DF increased. Intraclass correlation coefficients (ICCs) of intra-observer and inter-observer repeatability obtained for ROI sizes of 2 mm, 5 mm and 8 mm indicated good to excellent repeatability at all stretched levels. CONCLUSIONS: Shear wave elastography appeared to be a reliable tool to evaluate the dynamic stretching muscle stiffness with satisfactory repeatability at various stretched levels of gastrocnemius medius. Good to excellent repeatability was found using different ROI sizes.

Quantitative evaluation of passive muscle stiffness by shear wave elastography in healthy individuals of different ages.

OBJECTIVES: To investigate age-related changes on passive muscle stiffness in healthy individuals and measure the shear modulus in different age groups. METHODS: Shear wave elastography (SWE) movies of gastrocnemius medialis (GM) were collected during passive stretching induced by ankle rotation from plantarflexion (PF) to dorsiflexion (DF). A series of SWE images at ankle angles of PF 40°, PF 30°, PF 20°, PF 10°, 0°, DF 10°, DF 20°, and DF 30° were collected and shear moduli measured accordingly for analyses. RESULTS: Eighty-six healthy volunteers (27 children, 31 middle-aged adults, and 28 older people) were recruited. No significant difference was observed in the shear modulus between the three groups at ankle angles of PF 40°, PF 30°, PF 20°, PF 10°, and 0° (p > 0.05). The difference in the shear modulus among the three groups became significant as DF increased. At ankle angles of DF 10°, DF 20°, and DF 30°, the shear modulus was the greatest in the older group, followed by the middle-aged group and then the children group (p = 0.007, 0.000, and 0.000, respectively). CONCLUSIONS: Passive muscle stiffness increases with age, and the difference between age groups was pronounced only after reaching a certain degree of stretching. KEY POINTS: • The influence of age on passive muscle stiffness becomes pronounced only after reaching a certain degree of stretching. • Age should be considered when evaluating passive muscle stiffness in muscular disorders.

Ultrasound-Guided Percutaneous Release of A1 Pulley by Using a Needle Knife: A Prospective Study of 41 Cases.

Objective: The purpose of this study was to evaluate the efficacy of ultrasonography-guided percutaneous A1 pulley release with the needle knife for trigger finger. Methods: The prospective study included 21 patients (21 fingers) who underwent blind release with the needle knife and 20 patients (20 fingers) who underwent ultrasonography-guided release with the needle knife. The thickness and width of A1 pulley, clinical grade before and after release, complications, and operation time were compared between the groups. Results: The results showed that the ultrasonography-guided group had significantly better grade postoperatively and reached to 100% complete release in one time compared to the blind group (p < 0.05). Moreover, no any complications had been happened in the ultrasonography-guided group. A relatively longer operation time of the ultrasonography-guided group was observed compared to the time of the blind group. Conclusions: The needle knife is a very good tool for release of triggering fingers. Ultrasound provides a direct and precise visualization of the thickness, width and location of A1 pulley lesion. The combined use of ultrasound and the needle knife can achieve the best result for trigger finger. Moreover, the combination changes the traditional opinion and operator-dependent mode that were once widely adopted in the hospital of Chinese Medicine.