Hip and groin pain are common time-loss injuries in sport. This is particularly common in Gaelic sports, especially football. Our clinic has seen large numbers of GAA players over the years with hip and groin injury and footballers outnumber hurlers nearly 4:1. It is often argued that kicking is the main reason why football causes more groin injury but this is probably a little simplistic. Football by its nature requires more running and contemporary ‘transitional’ defensive systems require even higher fitness levels combined with sharper twisting and turning. Ball retention is a focus meaning a short hand-pass is often favoured over a kick-pass or longer kick. The old adage of ‘let the ball do the work’ doesn’t hold in this system – meaning players work harder. Players at all levels around the country are now also undertaking varying levels of conditioning. From unsupervised to one-on-one sessions, most teams perform gym-based conditioning over the winter months and pre-season. The combination of torsion forces (twisting the upper body relative to legs) higher load (how many metres you run a week) and less recovery time (more training sessions plus work/school/college = less time to recover) all add up to an overload pattern which is at the root of many of the hip and groin problems we see.

Hip and groin pain is the third biggest time-loss injury in field sports like GAA, rugby and soccer. Long before a player begins to miss games their performance tends to drop – sprinting, direction change and cutting all see decrements in performance. Worse still, because athletes often continue to play and train and there are no stitches or crutches to be seen, it can be hard for other athletes and coaches to understand why the athlete is not better. Similarly, the medical team often struggle to manage the symptoms and a pretty classic tactic is to move the ‘blame’ for this onto the athlete- you would be amazed how many athletes are relived to ‘have a diagnosis’ that things are not in their head. Worse again is the lack of an endpoint to when the problem will be resolved.

This is an emotive issue where a player, their manager and medical team will try anything to get them back training and playing. To be told hip surgery will sort this problem will make this better is “great news” for all involved. We all love to have an endpoint- “you will be back playing in 4 months”. Often this is delivered in tandem with them the news that if the surgery is not performed you will have arthritis aged 40. This makes surgery almost mandatory.

These are pretty emotive areas with some pretty scary outcomes. When fear, loss and anxiety are mixed into the decision process making a clear choice can be difficult. This article is aimed at taking the emotion out so some of the questions and answering it with the scientific information that is out there.

There has been an 18-fold increase in the number of hip arthroscopies in the USA between 1999 and 2009. The FAI-surgery rate has increased by over 600% among newly trained surgeons from 2006 to 2010. In Ireland GAA insurance figures show 314 hip surgeries in 2014 compared to 80 in 2007- a rise of 392%.

I remember the first time I encountered a hip labral tear. I was consulting on an intercounty hurler in 2005. He had a history of tight groins and intermittent flares of groin pain. An MRI confirmed a labral tear. An intra-articular injection of his hip helped to settle his pain, but it returned a few months later. At the time hip arthroscopy was not readily available in this country and was not an option for this player. With modification of training and rehabilitation input the player continued to train and play at an elite level until 2012. So what has changed since to see such an exponential rise in surgery?

It is a worthwhile exercise to discuss some of the terms that are commonly mentioned in this area.

This is a difference in shape from the norm (Figure 1) with either the ball (femoral head) or the socket (acetabulum) of your hip. It does not mean that there is a problem. This is commonly referred to as femoro-acetabular impingement (FAI). It means that you are at a biomechanical disadvantage compared to “normal” shaped hips. This does not guarantee that you will have a problem but does increase the chances of one developing. Its means there is a “possibility” of a problem developing. It is felt that morphology changes are far more common than we imagine and we know FAI morphology doesn’t guarantee you will have either pain or poor performance.

In ‘A’ the small solid arrow indicated the area of ‘extra’ bone seen in cam-type FAI. In ‘B’ the long interrupted arrow shows the head/neck offset we would label ‘normal’. It is worth noting that though the patient in ‘A’ had similar x-ray findings on both sides he was symptomatic on the right side only.

Pathology is where morphology combines with other factors to cause pain and dysfunction. Pathology implies that there is a “probability” there will be longer term damage. Much has been written on this in scientific literature.

To develop pathology you have to have 5 things:

(1) Abnormal morphology of the femur and/or acetabulum- the abnormal shape is present.

(2) Abnormal contact between these two structures- this shape increases impact between the structures.

(3) Especially vigorous supraphysiological (high-level/high-intensity) motion that results in such abnormal contact and collision- the athlete trains or plays at a high level with poor ‘control’ worsening this impact.

(4) Repetitive inefficient motion resulting in the continuous insult- the athlete does this a lot ie trains/plays a lot.

(5) The presence of soft-tissue damage- labral tear or ligamentum teres tear, the biggest risk factor for injury is previous injury, so soft tissue injury can cause further issues.

So it is worth bearing in mind that even if you have 1 and 2 or even 5 if you alter 3 and 4 you may manage very well.

A prospective study in professional ice-hockey showed this very well. Twenty-one players were followed for 5 years- 15 had labral tears in one or both hips. At 5 years 19 of the 21 were still playing professional hockey. The development of any hip and/or pelvis symptoms occurred in only 3 players (14%) within 4 years. Only 1 of the 3 players missed any games because of hip and/or pelvis symptoms (this was ITB pain which is most likely unrelated).1

Figure 2 A: FAI of both hips, B: focused x-ray of left hip, C: MRI of left hip showing bone change and labral tear (Arrow)

A number of recent studies from the Netherlands have confirmed what many clinicians in the field have believed for many years- in your adolescent years the more you train and the higher the intensity of that training the more likely you are to develop FAI morphology. The study looked at elite soccer players in Holland and compared the rates of development of FAI morphology. Basically the more often you trained and played at a higher level the more likely you were to develop FAI morphology.2

That’s why so many players who present with hip and groin pain on one side are often shocked to see the MRI findings of FAI are seen on both sides on imaging. This is a developmental issue, which may or may not cause an issue. It will only cause a real issue when the other factors outlined above are present.

This draws many parallels to knee meniscal surgery (shock absorber often called ‘cartilage’ in lay terms). Efforts to improve meniscal repair and minimally invasive surgery are the hallmarks of the efforts we make to preserve the meniscus- this is a shock absorber which protects the rest of the joint and the articular cartilage. In the past the surgical approach was very aggressive and much more tissue was removed than is now the norm. Over time it became obvious that this strategy caused considerable joint damage in later years- hastening the onset of osteoarthritis.

Nowadays even when a meniscal tear of the knee is confirmed, unless there are mechanical symptoms such as the joint locking or recurrent joint effusion (joint swelling) we try to avoid operating on the joint.

A good lesson to learn from previous findings is that case series for other surgeries (eg, meniscus tear, shoulder impingement) are often favourable, but subsequent randomised controlled trials (best evidence level) show no additional benefit over non-surgical or sham therapy.

We are making the same mistakes with hip surgery. Studies have shown that labral tears are, more often than not, asymptomatic even in an athletic population.3 Studies have also shown that tears in the labrum as large as 3cm may be present while the labrum still does its job.4 Unfortunately it has also shown that removing the labrum increases the force across the acetabulum- which may, in fact, predispose the patient to arthritis.5

Studies have shown that a number of movement patterns may predispose the athlete to develop pain in the presence of FAI- the athletes may develop one of the 5 issues outlined above.6 This is a factor of colliding variables. In the absence of a symptomatic labral tear, it is a little simplistic to think surgery to the area will fix this. It is often proposed that if the athlete does not gain significant relief or in fact abolition of their pain on an intra-articular injection it is unlikely they will benefit from surgery. This is not supported by any research but is based on some sensible thinking- if we neutralise any pain source within the joint and the pain persists this suggests there are a number of soft tissue structures around the joint which are causing some pain- these should be cleared first.

I regularly hear from patients that they are going to develop arthritis of their hip if they don’t have surgery to correct their FAI. Although some information exists on osteoarthritis secondary to grossly visible deformities (severely abnormal ball or socket shapes), there is almost no information on the natural course of more subtle femoral or acetabular deformities as present in FAI.7 There is an association between symptomatic FAI and development of OA.8 We don’t know who will develop OA but we do know the risk tends to be less as we get older. If we are to be scientific in our approach to the medical management of this issue we must respect this information.

This has been highlighted in the work of one of the most respected hip surgeons in the UK, his 2009 work followed a group of patients (90) with FAI and found “mild to moderate osteoarthritis in hips with a pistol-grip deformity will not progress rapidly in all patients. In one-third, progression will take more than ten years to manifest, if ever. The individual geometry of the proximal femur and acetabulum partly influences this phenomenon. A hip with cam impingement is not always destined for end-stage arthritic degeneration.”9

Even more worrying, no study to date has supported that arthroscopic surgery of the hip actually changes the outcome of whether arthritis will develop or not.8 The timing of surgery poses other real questions, as the severity of joint cartilage damage is associated with worse outcomes following surgery and more rapid progression to total hip replacement.10 A sobering thought.

Most scientists in the area of sports medicine agree that an evidence-based approach is in the patient’s best interests. They also agree that performing high-level research in sports medicine is difficult because athletes are in a hurry and want to ‘get the job done’. We need to take a moment here however to consider what we are trying to achieve. Taking the model of 5 colliding variables is a useful one to keep things sensible. Even though x-ray or MRI findings support bone shape changes or cartilage damage doesn’t mean surgery must happen. Of course there are situations where surgery is required, but it is imperative for those doctors and physiotherapists looking after teams to ensure 3 & 4 above (especially vigorous supraphysiological (high-level/high-intensity) motion that results in such abnormal contact and collision, repetitive motion resulting in the continuous insult and) are altered first.

I have listed references here in a manner similar to a scientific article as these facts are bound to irritate a number of people. I have tried to take some of the emotion and fear out of this topic and instead look at this from a scientific perspective. There are rarely black and white answers in sports medicine- the best option often being quite grey.

Those trying to help and guide athletes must be prepared to look beyond what appears to be a quick fix and use the information out there to guide their decision-making process.