In the last publication from my PhD thesis, I made a “digital twin” finite element model of the hip to predict damaging stresses in the cartilage during walking. I demonstrated this by simulating both hips in a single patient with Perthes’ deformity—one side affected and the other unaffected. The results of this demonstration showed the importance of considering not just the forces applied to the hip but also its motion, and similar techniques could be used to tailor patient-specific surgical or non-surgical management pathways for patients with residual Perthes’ deformity.

With a little website reshuffle complete, here’s another picture to round out the locations in my header. This time it’s Ledbury, my family home. The town can be seen poking out from behind the central hill if you look carefully.

A moment of opportunity—cycling over the Longfellow Bridge into a late autumn sunset, I heard a train stopping at Charles/MGH behind me. Pull the bike over, perch on the crash barrier, time it juuust right and you get this:

Some editing was needed later that evening as the low light was pushing my poor Fairphone 4 to its limits. I darkened the sky a bit and selectively gaussian blurred out some of the worst digital noise, only to add some finer noise for the aesthetic. I think it turned out pretty well.

I do music too! And sometimes I even want other people to listen to it. After years of on-and-off recording, please enjoy my first actual album: Bits // Peaces.

I’ve put stuff on SoundCloud before but this time I’ve taken the plunge and distributed my music to all the apps—including Spotify, YouTube Music, Apple Music, and of course Bandcamp.

Below I’m putting down a couple of thoughts and the lyrics¹ for each track.

First off, I’d like to offer a humble apology to all of my avid readers (who?) for my prolonged absence. In my defence, a Big Life Event™ got in the way. I’ll start this update by describing the BLE and then get sidetracked by a completely unecessary story of sentimentality, daring and hubris. Enjoy!

Big Life Event

So what’s new? In a breathtaking display of comic timing and self-preservation, I and my fiancée both moved to the USA to start postdoctoral academic jobs… in June 2025. More specifically, I’m now a postdoctoral research fellow at the new(ish) Institute for Mechanobiology at Northeastern University in Boston, where I can keep messing around with hips for a couple of joints. Maybe I could even peek at other joints too!

When we left off, I’d been trying to create a simple tool to improve Mastodon users’ experience of interacting with communities on Lemmy, Mbin and PieFed (or “LemBinFed” as I like to call them¹). This would be a bot that would only boost top-level posts from a community, to save Mastodon users from having to sift through out-of-context reply posts to find them.

The plan was initially make this bot using only Python and the Mastodon API: follow the community, read recent posts on the bot’s timeline, and filter out replies using the status.in_reply_to_id attribute. However, there is a critical problem with Mastodon: you can’t follow a LemBinFed community if there is a LemBinFed user with the same handle!

Back in the day, I used to spend a lot of time on Reddit. I still skim through the top posts on certain subreddits from time to time, but the site has now been sliding down the inevitable and crudely-named ensh*ttification spiral for some time. As with most social media platforms, there are alternatives on the Fediverse: platforms like Lemmy, Mbin and PieFed. These are formatted like Reddit: each page has a list of posts ordered using an algorithm that takes into account both recency and popularity (based on upvotes and downvotes). Clicking on each post will take you to that post’s comments, arranged in a similar way.

Update 26th January 2026: this paper was selected by Arthritis Society Canada as one of their Top 10 Research Advances of 2025! I’m incredibly honoured to be recognised by Arthritis Society Canada, and I would not have been able to complete my PhD research without their support.

That’s right, you get two summaries for the price of one this month. By a quirk of the peer review process and copyediting timeline, two of my PhD thesis chapters were published as journal articles within a week of each other! See here for my summary of the other one.

Changes to the shape of the hip joint caused by Perthes’ disease are linked to problems such as hip pain and arthritis later in life. But how exactly does deformity result in bad outcomes? One part of my PhD thesis looked into this question, and is available open access in the Journal of Pediatric Orthopaedics as:

Johnson LG, Zhang H, Joseph B, et al. 2025. Anterior hip clearance in residual Legg-Calvé-Perthes disease. J Pediatr Orthop.

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Another favourite illustration I produced for Discorder magazine is the very first one I contributed—way back in January 2021! Accompanying a review for “100 Block Rock”, a compliation album of music by artists based in Vancouver’s Downtown Eastside (DTES), this assignment really gave me a chance to explore some themes of hope and community based on the album’s lyrics.