Reliability, Validity and Responsiveness of the Polish Version of the Western Ontario Shoulder Instability Index (WOSI-PL) in Patients after Arthroscopic Repair for Shoulder Instability

Apart from imaging and physical examination for shoulder instability (SI), medical history with patient feedback should be considered to assess the patient's condition and recovery. The aim of this study was to evaluate psychometric properties of the Polish version of Western Ontario Shoulder Instability Index (WOSI)-one of the most frequently used patient-reported outcome measures for SI. During examination 1, 74 patients after arthroscopic repair for SI (age x¯ = 30.01 ± 8.98) were tested. Examinations 2 and 3 involved 71 and 51 patients, respectively. They completed the Polish version of the WOSI, the shortened version of the Disabilities of Arm, Shoulder and Hand Questionnaire (QuickDASH), the Short Form-36 version 2.0 (SF-36 v. 2.0) and 7-point Global Rating Change scale (GRC). The WOSI-PL demonstrated high internal consistency (Cronbach's alpha for total = 0.94), and test-retest reliability (Total ICC_2,1 = 0.99). High construct validity was found (89%) as the a priori hypotheses were confirmed. All domains and total scores of WOSI-PL showed a moderate to strong degree of responsiveness (ES = 0.37-0.44; SMR = 0.87-1.26). Minimal clinically important difference (MCID) for the Total WOSI-PL was 126.43 points/6% (95%CI 67.83-185.03) by the anchor-based method and 174.05 points/8% (95%CI 138.61-233.98) by the distribution-based method. The Polish version of the WOSI can be considered a reliable, valid and responsive PROM. It is recommended for assessing the quality of life in patients after arthroscopic repair for SI and can be applied in research and in the clinical setting for monitoring treatment and facilitating patient-centred therapeutic decisions.

Structural and mechanical aspects of hypoeutectic Zn-Mg binary alloys for biodegradable vascular stent applications

The study is concerned with the mechanical properties of Zn and three Zn–Mg double alloys with Mg concentrations: 0.5%, 1.0% and 1.5% in the form of rods with a diameter of 5 mm as potential materials for use in biodegradable medical implants, such as vascular stents. The materials were cast, next conventionally hot extruded at 250 °C and finally, hydrostatically extruded (HE) at ambient temperature. Occasionally HE process was carried at liquid nitrogen temperature or in combination with the ECAP process. After HE, the microstructure of the alloys was made up of fine-grained αZn of mean grain size ~1 μm in a 2-phase coat of 50–200 nm nano-grains of the fine αZn + Mg₂Zn₁₁ eutectic. The 3 to 4-fold reduction of grain size as a result of HE allowed an increase in yield strength from 100% to over 200%, elongation to fracture from 100% to thirty fold and hardness over 50% compared to the best literature results for similar alloys. Exceptions accounted for elongation to fracture in case of Zn-0.5 Mg alloy and hardness in case of Zn-1.5 Mg alloy, both of which fell by 20%. For the Zn-0.5 Mg and Zn–1Mg alloys, after immersion tests, no corrosive degradation of plasticity was observed. Achieving these properties was the result of generating large plastic deformations at ambient temperature due to the application of high pressure forming with the cumulative HE method. The results showed that Zn–Mg binary alloys after HE have mechanical and corrosive characteristics, qualifying them for applications in biodegradable implants, including vascular stents.

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Forming under high pressure allows to generate severe deformation in Zn–Mg alloys.

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HE reduces grain size of Zn alloys by 3–4 times in comparison to hot extrusion.

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HE increases YS by 200%, ε_f by 300% and HV by 50% in comparison to literature data.

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In Zn with 0.5 and 1% Mg no ductility reduction after the corrosion test was observed.

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Mechanical and corrosion properties qualify Zn alloys after HE for vascular stents.

Translation, cross-cultural adaptation and validation of the polish version of the Oxford Shoulder Score in patients undergoing arthroscopic rotator cuff repair

Background

The Oxford Shoulder Score (OSS) is a simple and reliable, joint-specific, self-reported outcome measure. It can be applied in patients with shoulder disease other than instability. The purpose of this study was to perform a translation, cultural adaptation of the Polish version of the OSS and to evaluate its selected psychometric properties in patients after arthroscopic rotator cuff repair.

Methods

Sixty-nine subjects participated in the study, with a mean age 55.5 (ranging from 40 to 65 years). The OSS has been translated using the widely accepted guidelines. All patients completed the Polish version of OSS (OSS-PL), the short version of the Disabilities of Arm, Shoulder and Hand Questionnaire (QuickDASH), the Short Form-36 v. 2.0 (SF-36) and the 7-point Global Rating of Change Scale (GRC).

Results

High internal consistency of 0.96 was found using Cronbach’s alpha coefficient. Reliability of the OSS resulted in Intraclass Correlation Coefficient (ICC) = 0.99, Standard Error of Measurement (SEM) = 1.14 and Minimal Detectable Change (MDC) = 3.15. The validity analysis showed a moderate (General health r = 0.34) to high (Physical role functioning r = 0.82) correlation between the OSS-PL and SF-36 and a high correlation between the OSS-PL and the QuickDASH (r = − 0.92).

Conclusions

The Polish version of OSS is a reliable and valid, self-reported questionnaire, which can be applied in patients with a rotator cuff tear undergoing reconstruction surgery. The very good psychometric properties of the Polish version of the OSS indicate that it can be used in clinical practice and scientific research.

Validation of the Polish version of the Western Ontario Rotator Cuff Index in patients following arthroscopic rotator cuff repair

BACKGROUND

The Western Ontario Rotator Cuff Index (WORC) is a joint specific outcome tool that assesses the quality of life in patients with various rotator cuff problems. Our purpose was to evaluate selected psychometric characteristics (internal consistency, validity, reliability and agreement) of the Polish version of WORC in patients undergoing rotator cuff repair.

METHODS

Sixty-nine subjects took part in the study with a mean age 55.5 (range 40-65). All had undergone arthroscopic rotator cuff repair in 2015-2016. Data from 57 patients in whom symptoms in the shoulder joint had not changed within 10-14 days were analyzed in a WORC test-retest using the Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC). WORC was compared to the short version of the Disabilities of Arm, Shoulder and Hand Questionnaire (QuickDash) and the Short Form-36 v. 2.0 (SF-36).

RESULTS

High internal consistency of 0.94 was found using Cronbach's alpha coefficient. Reliability of the WORC resulted in ICC = 0.99, agreement assessed with SEM and MDC amounted to 1.62 and 4.48 respectively. The validity analysis of WORC showed strong correlations with QuickDash and SF-36 PCS (Physical Component Summary), while moderate with SF-36 MCS (Mental Component Summary). WORC had no floor or ceiling effect.

CONCLUSIONS

The Polish version of the WORC is a reliable and valid tool with high internal consistency for assessing the quality of life in patients undergoing arthroscopic rotator cuff repair.