By Arthur Sullivan

There may be worse injuries, but few have the kind of shuddering impact on a season that an anterior cruciate knee ligament injury has.

Ask Colm Spillane, the young Cork hurler, or Séan Finn in Limerick. Those two talented young hurlers were expected to make strides towards their counties' first teams in 2016, but before the season had really started, theirs were already over thanks to that 'dreaded' ACL (anterior cruciate ligament). Ger Aylward (Kilkenny) and Pat Donnellan (Clare) suffered similar fates recently.

The duration of recovery is inescapably and undeniably long. A recovery period of 10 months is generally seen as the minimum time required - it can sometimes be shorter, but is often longer - and that's the reason why news of a cruciate knee ligament injury spells the end of someone's season, regardless of when it occurs.

The biology is relatively straightforward. As one of the prime stabilisers in the knee, the anterior cruciate ligament is absolutely fundamental for the most basic of sporting manoeuvers. Assuming there are no further complications beyond the rupture itself, a torn ACL, at minimum, requires serious surgery and detailed rehabilitation programmes.

Yet, there is good news. Medical and scientific knowledge around the treatment of the injury has improved rapidly in recent years. The amount of ACL injuries that happen nowadays mean surgeons have become increasingly adept at undertaking successful surgeries. Even in severe, complicated cases, paths to recovery are clear and well worn.

One of the best recent examples of a textbook recovery from an ACL injury was that of Dublin footballer Ciarán Kilkenny. This time two years ago (March 8 to be precise), Kilkenny ruptured his ACL in a league game against Kildare at Croke Park.

Just four minutes were gone in the game and the injury looked relatively innocuous at the time.

"I thought I had done my medial ligament so I thought initially it wouldn't be as serious as it turned out to be," Kilkenny told GAA.ie recently. "When I went in and met Ray Moran (at the Santry Sports Clinic), I was almost thinking, this will be a nice little four week break, do some gym work and then recover. But then I went in and he told me it was my cruciate ligament."

One year earlier, Kilkenny had made an unexpected and highly publicised early return from a contract in the AFL with Hawthorn. Aged just 19, Kilkenny was tipped for more or less immediate stardom, and he played a prominent role in Dublin's All-Ireland win in 2013.

He was expected to make an even greater impact in 2014, and that's why that injury, coming as it did on a dark, cold, March night, was such a bolt from the blue to a 20-year-old who seemed to have everything neatly laid before him on the road to a top-level career.

"It was a shock and because I wasn't prepared, I kind of had been very positive before I got the news. I had been fairly certain that it wasn't a cruciate so when I found out that it was, I was kind of in auto-pilot for two or three minutes as he told me, as I processed the whole fact that I would not be playing at all for the year.

"I had done my medial against Tyrone before and because it was the same kind of feeling, the same kind of impact, I thought it was the same again this time. So then after the cruciate news, the first few weeks were tough as I tried to get my head around it.

"I tried to stay as positive as I could. When you get these sorts of injuries, it's all about staying positive and trying to look at the advantages of getting such an injury. I had been playing football and hurling for so many teams for so many years so ideally, I started to view it as a break."

Kilkenny had a number of things in his favour. Aged just 20, and blessed with a naturally high athletic capacity, his body was typical of the kind born to recover quickly from serious injury. His attitude, as the previous quote suggests, was also hugely beneficial to him.

But perhaps most important of all, was the timing. Kilkenny's injury happened late enough in the year for him to know there would be no possible return before the year was over, sparing him false hope, but early enough for him to aim, entirely realistically, to be returning to fitness in time for the following year's pre-season.

As he says, once he got over the initial shock and disappointment at missing out on the 2014 season, Kilkenny started to view the news as a positive thing in his life and career as a whole.

Kilkenny is typical of the kind of player at the centre of the 'burn-out' debate in Gaelic football. A dual player in demand by Dublin county teams from a very young age in both codes, highly committed to his club Castleknock and to his college St Pat's Drumcondra, Kilkenny has played for many, many teams despite still being just 22 years old.

The commitment and availability required of a young man to play and train for so many teams from such a young age means that many players of Kilkenny's profile often miss out on some of the things non-elite GAA players may take for granted.

As well as recognising that, Kilkenny also saw an opportunity for him to develop further as an athlete and as a footballer during his period of absence. "It was a chance for me to develop as a person, a good time for me to get myself stronger in different aspects, in the gym and so on.

"In terms of life in general, I got to go to Zambia and that made me appreciate things a lot more," said Kilkenny, who was made a special ambassador for Edmund Rice Development, which supports the work of the Christian Brothers in Africa. Kilkenny travelled to Zambia during the summer of 2014.

"It made me more aware as a player as well because I got to look after a few teams in college and that brought new awareness from being on the line looking on. Tactically it improves you, where to be moving, where to be looking and that kind of thing.

"Then I suppose physically you can work on retuning certain areas. I worked on my quads a lot. I had six to eight months to get myself into the best condition that I could and I came back physically in a way that I thought I was stronger and quicker. I wasn't necessarily bigger, but I was definitely a more complete athlete after the injury than before."

It seems almost counter-intuitive. How can an athlete laid low by an injury as serious as an ACL, unable to run or train for months, be a better athlete after recuperation than before?

"I became so much more aware of the mechanics of being a sports-person. Watching your diet, and doing the various speed exercises. Targeting the muscles in your legs and your backside that make you quicker. All that balance makes you quicker I suppose and better off the mark. Simple things, but only when you really engage with them.

"I knew my own body better than ever before. When you come back from the injury, you have to be selective about what you play, whether it's with the club or if you need a break, if you're doing too much.

"I became aware of what kind of loads you need to be doing, because in the past, I would have been a big fan of doing extra running on my own and this year (2015) we were so lucky to have such a great medical and physical team with Dublin under Martin Kennedy and I just did exactly what he told me to do. I watched my diet, did the training I was told and I was flying. I felt I was great in myself. I felt so healthy doing it all. I wasn't fatigued or tired."

With his mind focused on doing everything right in order to recover as well as possible, Kilkenny followed his rehab programme to the letter. "The way I looked at it was, six months is 24 weeks so if I put in 24 weeks of gym work, then I will be back playing football. I just took it week by week. One week gone, 23 left..."

Eventually, the pile of weeks had dwindled to a few. Kilkenny was a spectator as Dublin were stunned by Donegal in the 2014 All-Ireland semi-final, and as disappointed as he was, he knew his own battle was close to being won.

Back in full training by December 2014, he made his playing return in a low key game for his college St Pat's Drumcondra against Blanchardstown IT - "Graham Geraghty was playing the same day and the adrenaline was flowing through me" - and he returned for Dublin competitively just over a year ago, coming on a sub in the league win against Donegal on February 7.

Again, it was a cold, late winter's Saturday night at Croke Park, the exact same scenario as when he had suffered the injury one year before. It was actually this coming weekend one year ago that Kilkenny started his first game for Dublin since the injury, playing the full 70 minutes in a two-point defeat to Kerry in Killarney.

"In the Donegal game, I came on as a sub, and I was running up and down, getting the aerobic capacity going. I was conscious of my knee that night but then, as soon as I got through that game, as soon as you get through that big hit, you're grand and you've nothing to worry about. I have felt nothing since. It's just totally back to normal. Ray Moran did a good job on it and I haven't felt anything since."

Looking at the season Kilkenny had in 2015, his recovery is a shining example of what the likes of Seán Finn, Colm Spillane, Ger Aylward, Pat Donnellan and any other young sportsperson who suffered an ACL recently can aspire to in the difficult months ahead.

Kilkenny was a markedly improved footballer in 2015. An early contender for Footballer of the Year, he was arguably Dublin's top performer in the Leinster Championship and he scored 0-18 from play last summer, scoring a minimum of 0-2 in every game except the final.

The hours, days, weeks and months away from the bright lights had clearly been spent intelligently and productively. When he collected his second All-Ireland senior medal and his first All Star last winter, he did so as arguably a better player than he would have been had he not suffered that 'dreaded' season-ending injury nearly two years earlier.

It's a thought which should inspire. The idea, however alien it seems at first, that an ACL injury can be your friend in the end.