Usability and outcomes of self-monitored surgical wound healing using a smartphone-based application by patients following neurosurgery.

BACKGROUND: The Radboudumc developed a smartphone application (WondGezond) to collect surgical wound-healing information provided by the patient. AIM: To evaluate usability and outcomes to assess its potential for early surgical site infection (SSI) detection. METHODS: Patients surgically treated for degenerative spinal disorders or carpal tunnel syndrome between August 2020 and February 2023 were enrolled one day post surgery and asked to download the app via a quick-response (QR) code. Participants uploaded a photo and answered four questions about their wound daily, for 14 days. Afterwards, participants indicated whether they received treatment for a suspected SSI (participant-reported outcome). Two neurosurgeons independently assessed photos and questionnaire answers for suspected SSIs (physician-assessed outcome). The association between both outcomes was determined by calculating sensitivity, specificity, and positive and negative predictive value (PPV/NPV). FINDINGS: After 2009 surgeries, 1695 QR-codes were distributed and 412 (21%) were activated. In all, 232 (56%) participants completed the 14-day period of whom 22 (10%) reported SSI treatment. Physician assessment identified 15 (7%) SSIs. Concordance was reached in 88% of cases. Among 27 discordant cases were 17 false-positives and 10 false-negatives, resulting in low sensitivity (33%) and PPV (23%), but high NPV (95%). CONCLUSION: WondGezond provides clinicians with information regarding wound healing and SSIs to follow-up on patients at risk, while possibly also reducing antibiotic (over)treatment and unnecessary visits for patients without issues in wound healing. However, the low participation and false-positive results render the app in its current form unsuitable for surveillance purposes. Further validation of WondGezond is required.

Finite-element analysis of failure of the Capital Hip designs.

The Capital Hip implant was a Charnley-based system which included a flanged and a roundback stem, both of which were available in stainless steel and titanium. The system was withdrawn from the market because of its inferior performance. However, all four of the designs did not produce poor rates of survival. Using a simulated-based, finite-element analysis, we have analysed the Capital Hip system. Our aim was to investigate whether our simulation was able to detect differences which could account for the varying survival between the Capital Hip designs, thereby further validating the simulation. We created finite-element models of reconstructions with the flanged and roundback Capital Hips. A loading history was applied representing normal walking and stair-climbing, while we monitored the formation of fatigue cracks in the cement. Corresponding to the clinical findings, our simulation was able to detect the negative effects of the titanium material and the flanged design in the Capital Hip system. Although improvements could be made by including the effect of the roughness of the surface of the stem, our study increased the value of the model as a predictive tool for determining failure of an implant.