Sonny Rennison, a 14-year-old from Melbourne, became the first Australian to reach a grand slam boys' wheelchair singles final when he competed at this year's US Open. His path to Flushing Meadows began a decade ago, when he was diagnosed with a rare bone condition that threatened his tennis dream.
Rennison was diagnosed with Perthes disease and multiple epiphyseal dysplasia at age four, leaving the ball joint of his hip to waste away and making standing or running damaging. Through the Victorian government's Access for All Abilities Play program, he was introduced to wheelchair tennis and soon connected with coach Rob Hilbig. A chance encounter with Australian wheelchair tennis stars Dylan Alcott and Heath Davidson at the Australian Open led to an invitation to join them on court and an introduction to Tennis Australia's national development wheelchair coach, Greg 'Crumpy' Crump.
By age 12, Rennison had climbed to 16th in the world junior rankings. This year, after reaching No. 8, he earned a place at the US Open junior tournament. He won his semi-final in straight sets before losing the final to the top seed, Matthew Knoesen, 6-0, 6-2. Despite the loss, Rennison's achievement marks a milestone for Australian wheelchair tennis.
In a first-person account for Good Weekend magazine, Rennison's mother, Emma, described the challenges of his early years. 'I bit my lip, holding back my tears as I repeated the words the doctor used to explain that our sport-obsessed son couldn't walk any more,' she wrote. She recounted the family's loneliness and the difficulties and expense of accessing wheelchairs, equipment and funding, as well as the travel that divided the family when her daughter Evie-Rose also required major surgery.
Rennison represented Australia at the BNP Paribas World Team Cup in Turkey. The US Open became the first grand slam to host a junior wheelchair tournament in 2022, followed by the French Open in 2024 and the Australian Open in 2025.
Analysis
Why This Matters
- Highlights the importance of inclusive sports programs for children with disabilities, showing how community and government support can enable participation.
- Demonstrates the role of early intervention and mentorship from established athletes in overcoming significant medical challenges.
- Sonny's success at a grand slam level may inspire other young athletes with disabilities and raise the profile of wheelchair tennis.
Background
Sonny Rennison's condition, Perthes disease, is a rare childhood hip disorder where blood supply to the ball joint is disrupted, causing the bone to waste away. He was later also diagnosed with multiple epiphyseal dysplasia, a condition that affects joints throughout the body. After months of misdiagnosis, the family found the correct specialist. The US Open junior wheelchair tournament debuted in 2022, followed by the French Open in 2024 and the Australian Open in 2025. Rennison began playing wheelchair tennis at age five and was mentored by Dylan Alcott and Heath Davidson, who helped open doors to the sport.
Key Perspectives
This section omitted as sources carry only one perspective (the parent's account) without conflicting views.
What to Watch
- Rennison, now ranked 8th in the junior world rankings, may qualify for the French Open and Australian Open junior divisions, which have opened in recent years.
- His ongoing medical treatments and surgeries will be balanced with training and competition, potentially influencing his career trajectory.
- The expansion of grand slam junior wheelchair divisions could create more opportunities for young athletes globally.
Checked
12 claims in this story checked against 1 source: 10 supported.
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- SupportedThe quoted words about holding back tears and repeating the doctor’s words match the source.The Age - Latest News: “I bit my lip, holding back my tears as I repeated the words the doctor used to explain that our sport-obsessed son couldn’t walk any more.”
- Not in the sourcesThe first-person writer is identified as Sonny’s mother Emma.The Age - Latest News: “My four-year-old son gazed up at me from my lap, brown eyes shimmering as his trademark smile faded from his cherubic face.”
- Not in the sourcesThe first-person account was written for Good Weekend magazine.The Age - Latest News: “Read more from Good Weekend magazine:”
- SupportedSonny Rennison reached the US Open junior wheelchair final.The Age - Latest News: “He slapped hands with Crumpy, reached for me, then stretched across the barrier to wrap his arms around Heath, burying his face into his neck.”
- SupportedRennison was the first Australian to reach a grand slam boys’ wheelchair singles final.The Age - Latest News: “winning six consecutive games to become the first Australian to reach a grand slam boys’ wheelchair singles final.”
- SupportedRennison was 14 and from Melbourne when he reached the US Open final.The Age - Latest News: “This year, at 14, Sonny reached No. 8”
- SupportedRennison was diagnosed at age four with Perthes disease and multiple epiphyseal dysplasia.The Age - Latest News: “That day, we were told Sonny had a rare bone condition called Perthes disease. ... Something called multiple epiphyseal dysplasia. Spoiler alert. It was.”
- SupportedThe condition threatened his ability to walk and damaged his hip when he stood or ran.The Age - Latest News: “The blood supply to his hip was disrupted, leaving the ball joint to waste away. Any impact, from running to simply standing, would destroy the hip further.”
- SupportedAt 12, Rennison was ranked 16th, and this year he reached No. 8.The Age - Latest News: “By 12, Sonny had climbed the world rankings, reaching 16th at the end of 2024. ... This year, at 14, Sonny reached No. 8”
- SupportedRennison won his semi-final in straight sets and lost the final to top seed Matthew Knoesen, 6-0, 6-2.The Age - Latest News: “Sonny launched his US Open campaign with a straight-sets victory, securing a place in the semi-final. ... His opponent took the match – 6-0, 6-2.”
- SupportedRennison represented Australia at the BNP Paribas World Team Cup in Turkey.The Age - Latest News: “His goal was to represent Australia at the BNP Paribas World Team Cup ... “Matey, how’d you like to come to Turkey?””
- SupportedThe US Open introduced a junior wheelchair tournament in 2022, followed by the French Open in 2024 and Australian Open in 2025.The Age - Latest News: “In 2022, when Sonny was 10, the US Open became the first grand slam to debut a junior wheelchair tournament ... This was followed by the French Open in 2024, and the Australian Open in 2025”