Do I need surgery after ACL rupture? Not necessarily! Does this response surprise you?
To begin with, did you know that people who choose to rehab without ACL reconstructive surgery potentially have:
- an excellent chance of returning to their activities and sport
- a shorter time period from their injury to return to sport
- the potential for the ACL to heal on its own
- potentially less risk of arthritis
Therefore, read on to find out more and to explore the what the research says.
First of all, ‘ACL’ stands for ‘Anterior Cruciate Ligament’ and it is one of the four major ligaments in your knee. Importantly, it has a major role in the integrity and stability of the knee as it connects the femur (thigh bone) to the tibia (shin bone). You can read more about the function of the ACL in How to reduce the risk of ACL injuries in skiers. Part 1.
For those of you who ski, play football or take part in a sport that involves a lot of cutting and pivoting then you are probably familiar with the threat of an ACL tear/rupture (these terms will be used synonymously throughout this blog). Without a doubt, if you have sustained this debilitating knee injury, ‘do I need surgery after ACL rupture’ is a question that you be asking.
The answer is not straight forward but surgery after ACL rupture is not always necessary. Really, I hear you ask? Historically, surgical treatment has been encouraged for those involved in sports or jobs that require pivoting, twisting and cutting or heavy manual work. For this reason, skiers, footballers, basketball players and other sportsman / women have traditionally always had surgery recommended to them. However, professionals are now disputing whether this is necessary.
If you have ruptured your ACL this season, then no doubt you are experiencing a range of emotions. Indeed, many people wrongly assume that they will need surgery to have their ACL repaired. Whether this belief comes from talking with other people who have ruptured their ACL and had a repair, from internet searches or a combination of both, it is a widely spread misconception. Conversely, it may stem from the fact that historically there has been insufficient evidence to compare surgical versus conservative management of the ACL (Linko et al 2005).
To clarify, after an ACL rupture, the aim of reconstructive surgery is to restore stability to the knee. But can you do this without going under the knife? Yes you can, through education, rehabilitation and training. However, this is quite a complex topic. There is no one size fits all. Whether you opt for conservative (non-surgical) management or surgical repair you will also need to consider the length of the rehabilitation process and the timing of your decision making. Furthermore, it is essential to consider not just the physical factors involved but psychological factors too. An ACL injury can have a significant affect on a persons well-being.
If you don’t have an ACL, you potentially lose a key restraint of the knee. However, it is possible for the surrounding muscles to compensate for this. In fact, higher level and stronger athletes often have better ‘neuromuscular control’ of their knee joint.
Neuromuscular control is a largely unconscious mechanism which activates dynamic restraints of a joint to prepare it for movement. In other words, it prepares and activates the muscular system for motion, load and stability. Undoubtedly, athletes potentially have better and more responsive muscles. Therefore, they are likely to have enhanced neuromuscular control. In the past, candidates for conservative management of the ACL have often been fairly sedentary people. This population does not need a high level of dynamic knee control. However, could it be that athletes and sports men and women will actually compensate better and make good candidates for rehabbing their knee without ACL surgery?
Thankfully, there is more evidence emerging to support conservative management of an ACL tear in active and sports people. Monk et al, (2016) looked at surgical versus conservative management for treating ACL injuries. They performed a comprehensive literature search and concluded that ‘for adults with acute ACL injuries, we found low-quality evidence that there was no difference between surgical management (ACL reconstruction followed by structured rehabilitation) and conservative treatment (structured rehabilitation only) in patient-reported outcomes of knee function at two and five years after injury’.
We can also look at a case written up by Weiler et al. in 2015. They reported on an English Premier League football player who returned to play in less than 8 weeks post ACL rupture without surgery! We can also explore the case of Peter Wallace, a National Football League player who re-ruptured his ACL graft and continued to play for 2 years without an ACL in his knee. Has this pricked your interest?
Certainly, these cases are hugely significant. For people who have an ACL reconstruction, they usually have months of rehab prior to surgery. This is then followed by another nine months of rehabilitation post-surgery before they can return to sport. Could ACL rehab without reconstruction hugely reduce the length of rehab time needed before return to play? Many people opt to have surgery due to the misconception that they will recover faster. However, this is not usually the case.
What does the research say?
Additionally, here are some other findings from studies that compared quality of life and / or return to play between groups that had an ACL reconstruction and those that were ACL deficient:
- Roos et al. (1995) compared the proportion of soccer players still playing 7 years after an ACL injury. They found no difference between the players that had surgery and those that did not.
- Frobell et al, (2010) showed a modest return to pre-injury activity level at 5 years after a tear of the ACL. They found that there was no difference between the groups treated with early ACL reconstruction, delayed ACL reconstruction or those treated with rehabilitation alone.
- Smith et al. performed a systematic review in 2014. They selected studies that looked at isolated ligament reconstruction versus non-surgical management following ACL rupture. They concluded that ‘the current literature is insufficient to base clinical decision-making with respect to treatment opinions for people following ACL rupture’, however ‘whilst based on a poor evidence, the current evidence would indicate that people following ACL rupture should receive non-operative interventions before surgical intervention is considered’.
- In 2015, Fiblay et al, performed a systematic review and meta-analysis which revealed similar knee-related quality of life scores in ACL deficient and ACL reconstructed groups .
- Wellsandt et al. (2018) found that favourable outcomes can occur after both operative and nonoperative management of ACL injuries with the use of ‘progressive criterion-based rehabilitation’. However, in their conclusion they cited the need for further study to identify who are the best candidates for surgery versus conservative management.
Interpret the research with caution
Undoubtedly, as many of the researchers have pointed out, it is important to interpret the evidence with caution. Many of these studies were carried out on small populations and there were limitations to the research conducted. However, whilst the evidence from the studies I’ve mentioned above is not robust enough to make a concrete decision one way or the other, it is surely a reason to start to question whether ACL surgery is always necessary.
What about the risk of knee arthritis?
Another reason that ACL reconstruction has frequently been recommended is that it was previously thought that your risk of knee arthritis was significantly higher if you did not have surgery after an ACL rupture. However Dhillon (2014) noted that this belief may have been prevalent because there was no evidence for or against this. There is little research comparing osteoarthritis in an ACL deficient knee with a reconstructed one.
‘ACL reconstruction can’t prevent osteoarthritis’
However, research is now available that shows no difference in knee osteoarthritis between ACL reconstructed knees and ACL deficient knees (Fink et al 2001, Van Yperan et al. 2018). Delincé and Gahfil (2011) stated that ‘at present it is not demonstrated that ACL-plasty (ACL reconstruction) can prevent osteoarthritis’. In 2008, Neuman et al, looked at the prevalence of knee arthritis 15 years after nonoperative treatment of ACL injury. They concluded that ‘in patients willing to moderate their activity level, initial treatment without ACL reconstruction should be considered because favourable outcome in terms of knee function, symptoms and radiographic OA (osteoarthritis) can be obtained in the long term with nonoperative treatment’.
The rational behind recommending ACL reconstruction to help decrease the risk of osteoarthritis was that if you do not have an ACL, you may have more instability of the knee joint which could lead to an increase in meniscal (cartilage) injuries and joint degeneration. However, we now know that an ACL deficient knee doesn’t necessarily mean an unstable joint. Whats more, it is not just instability that potentially leads to arthritic changes. The trauma of the injury itself leads to an inflammatory soup within the knee. This leads to elevated levels of biochemical factors, such as inflammatory cytokines. These have been cited to play a role in cartilage degeneration and collagen destruction (Hong et al 2015, Larsson et al 2017).
Do you know what is involved in an ACL reconstruction?
To secure an ACL graft the surgeon must cut through muscles and soft tissue and drill holes in the bone. The surgical process, which was previously thought to decrease the change of osteoarthritis later in life, may actually increase your chances of developing it through the trauma of the techniques involved (Filbay, 2017, Frobell. et al 2013, Larsson, 2017). Larsson et al. (2017) stated that ‘our results strongly suggested that surgical reconstruction of a ruptured ACL constitutes a second trauma to the injured joint that leads to a prolonged elevation of already high synovial fluid levels of inflammatory cytokines, or to a secondary elevation when performed later after injury’. In other words, they suspect that the secondary trauma involved in the surgical process prolongs the inflammatory effect which in turn may increase the risk of arthritis.
One of the biggest studies carried out to look at surgical versus non-surgical management of ACL ruptures was the KANON trial (Frobell et.al. 2010) They found no difference in pain, return to pre-injury activity level, radiographic osteoarthritis (OA) and meniscus surgery between the groups. So as you can see, more and more evidence is emerging that suggests reconstructive surgery may not only not reduce the risk of arthritis but may actually play a role in exacerbating arthritic changes in the knee joint.
Rehabilitation is key
Interestingly, there is also some evidence to suggest that the timing of the surgery can have an impact on knee arthritis. Culvenor et al. (2019) found that there was a loss of cartilage in the patellofemoral (kneecap-knee) joint following ACL rupture, but they also found that this was greater in subjects that had an early reconstruction compared with a delayed repair. This helps to highlight the importance of rehabilitation for both people that wish to have there ACL reconstructed as well as those who don’t.
Will I need further surgery?
Some studies show that if you do not have your ACL reconstructed the chances of needing further surgery are higher than in ACL reconstructed patients. However, most of these studies do not take into account that many people who have their ACLs reconstructed may have concomitant surgeries at the same time (Larsson et al. 2017). For example, a meniscal repair alongside an ACL repair. As far as I am aware, there is no evidence available to suggest that follow up surgery in ACL deficient knees was necessary due to not having a reconstruction. In other words, the need for further surgery may be due to the initial trauma that tore the ACL also injuring other structures.
On the flip side of the coin, bear in mind that if you have your ACL reconstructed it doesn’t take away the risk that you may need further surgery. As many as one in five ACL-reconstructed individuals undergo knee surgery within 6 years of ACL reconstruction (Hettrich et al. 2013) and as many as one in four individuals suffer a graft re-rupture or contralateral ACL rupture within 15 years of ACL reconstruction (Bourke et al. 2012).
To sum up, there is no way to know if further surgery will be required whether you have an ACL reconstruction or not. Even as far back as 1983 Noyes et al. stated that ‘since it is often not possible to reliably predict which patient will or will not improve, it is advisable that all patients enter a rehabilitation program. They must be carefully followed, as it may take six months or longer before the true functional disability can be defined’.
But an ACL rupture can’t heal, can it?
Due to factors such as the anatomy of the ligament, biomechanical forces, poor blood supply to the ACL and its intrinsic properties it is widespread belief that the ACL cannot heal. However, although this is still a controversial topic there is evidence to suggest that the ACL can heal itself!
Several papers have reported spontaneous healing of the ACL after acute rupture (Fujimoto 2020, Costa-paz, 2012; Marangoni, 2018; Roe, 2016; Ihara, 2017). Costa-Paz et al. (2012) and Fujimoto et al. (2002) not only reported completed healing of the ACL in their subjects, but they also stated that most patients reported return to their pre-existing athletic level. Ihara & Kawano (2017) went as far to say that their findings indicated that the ACL has a high intrinsic healing capacity. Whats more, they also reported that it is clear that the healing capacity of the ACL has been underestimated.
Does everyone with an ACL rupture have healing potential? That we don’t know. Unfortunately, there are only a few reported cases. This could this be because so many people have surgery and therefore the ACL deficient knee has been overlooked. Alternatively, it could be because not many people who are ACL deficient are followed up and rescanned later down the line to see whether or not the ACL has healed. Either way, there is not yet enough data available for us to learn more.
Can I return to skiing without an ACL?
Yes you can! I’ve rehabbed numerous skiers and ski instructors back to the slopes without an ACL in their knee. Some choose to wear a knee brace, although sometimes this is more for psychological reasons than physical limitations. Others have such good neuromuscular control of their knee joint that they happily ski without any issues.
In my opinion skiers can make very good candidates for rehabbing their knee without surgery. Usually skiers are fit, strong and motivated. In fact, there is some evidence to suggest that the mind set of a person without an ACL may be one of the biggest factors influencing return to play. As skiers tend to have high thrill seeking levels, many easily fall into this category.
Interestingly, a study by Grindem et al. (2012) caught my eye when I was looking at the research. They compared a return to pivoting sports 1 year after an ACL tear in patients who had a nonoperative versus an operative treatment course. Skiing was classified as a level 2 pivoting sport (a demanding sport that does not involve quite as much twisting as football and basketball). 17 out of the 27 people in this group were alpine skiers. At 1 year follow up, 24 out of the 27 people (88.9%) in the non-operative group had returned to their sport compared with 21 out of 27 (77.8%) in the operative group. The non-operative group outshone the operative group!
Do I need surgery to return to sports that involve cutting and twisting?
This is tricky because obviously these type of sports impose very high demands on the knee joint. For this reason, there are many considerations to take into account. In short, these include but are not limited to:
- psychological readiness
- whether a knee brace is necessary or could be worn (many sports don’t allow return to play with a brace)
- the level of sport you wish to return to.
Clearly, gradual reintegration to your sport is of vital importance. Furthermore, ACL rehabilitation must be progressive. Undoubtedly, If you try and do too much too soon or without being physically prepared the risk of re-inury is high.
Interestingly, the ability to cope without an ACL is not actually a new concept. Noyes et al. discussed it in detail in 1983. As part of their “rule of thirds,” they hypothesized as many as 1/3 of patients with ACL deficiency could function well with some level of pivoting and cutting activity without any functional instability or giving way.
You can return to cutting and twisting sports without an ACL
Of key note is that various research has indicated that it is possible for people to return to high level activities, including jumping and cutting without an ACL (Hurd et al, 2009, Grindem et al 2012). Importantly, surgery does not increase your chances of returning to sport and does not allow for a quicker recovery (Frobell, 2013; Grindem, 2016; Keays, 2019; Weiler, 2015;).
- Johnson et al. (2003) stated that ‘The fact that a patient wants to continue to participate in high-level sport is not in itself an indication for surgery’
- Hurd et al. (2009) ‘when the patient is carefully screened and monitored by a clinician, an individualized approach to ACLD (ACL deficient) knee-injury management may allow for a potential return to sport without surgery’.
- Delancé et Ghafil (2013) stated that ‘Studies comparing surgical and conservative treatments confirm that ACL reconstruction is not the pre-requisite for returning to sporting activities’
- Costa-Paz et al. (2012) reported that ‘patients were able to return to sports activities at or near the same level as before injury and suggest the need to review the theory that the healing capacity of the ACL is poor’.
There is a positive trend towards returning to sport with an ACL
Indeed, these studies show a very positive trend towards return to sports without an ACL. However these results need to be interpreted with some caution. Firstly, although the subjects returned to their sporting activities, it is widely unknown if all the subjects returned to their previous level or play and performance. Secondly, it is also not known if they maintained their sports participation over time and what long-term consequences they may suffer regarding subsequent injuries and knee osteoarthritis.(Meuffels et al. 2009, Grindem et al. 2011). Therefore, as you can see further research is needed to help us establish the longer term effects of returning to sport without an ACL.
Return to sports criteria
There is no set criteria for when a person without an ACL can return to sports. Fitzgerald et al. (2000) suggested a screening examination for return to sports consisting of four one-legged hop tests, the incidence of knee giving-way, a self-report functional survey and a self-report global knee function rating which showed promise. However, it is also important to make any screening sports specific and incorporate tests and challenges that mimic return to play.
As I mentioned before, recovering from an ACL rupture can be quicker without surgery. Think back to my mention of the English Premier League football player who returned to play in less than 8 weeks post ACL rupture without surgery!
What if I have other knee injuries alongside my ACL rupture?
When an ACL is torn, due to the trauma and mechanisms involved it is not uncommon to sustain associated injuries to the knee. Without a doubt, these should be considered in the decision making process. Surgery may be needed if there are multiple structures injured leading to debilitating instability of the knee. However, this decision needs to be made on a case by case basis. There is rarely a reason why a period of rehabilitation cannot be trialled prior to making a decision as to whether or not surgery is necessary, even when other injuries are involved.
In terms of research, as far as I am aware there is no evidence that has looked at sportsmen and women returning to play with an ACL deficient knee combined with other injuries. Studies looking at return to sports in players without an ACL usually rule out additional injuries when selecting candidates for their study (Paterno 2017, Hurd et al 2008, Fitzgerald GK et al, 2000). The current return to play research has been conducted on people with isolated ACL ruptures. However, this by no means indicates that it is not possible to avoid surgery if you have additional injuries.
Where do I start?
An ACL rupture is a big injury which can have huge psychological effects. The frustrations related to the effects that an ACL rupture has on day-to-day life, work and sport are significant. Plus initially, the knee may be extremely painful which can be tiring to manage. Months of physiotherapy is involved regardless of whether you have reconstructive surgery or manage your ACL with rehabilitation only. Rehabbing any injury can be a series of highs and lows.
Start by finding a physiotherapist with experience in managing ACL tears. Do this as soon as you can after your rupture. Many people like to wait until any pain and swelling have subsided, but early input is key to learning how to rehab effectively. Ihara & kawano (2017) reported that ‘early mobilization of the knee creates a time-dependent response of the injured ACL to physiological mechanical stress’.
Educate yourself about your injury and your options. Consider a surgical opinion as the management of an ACL deficient knee requires input and advice from a range of health care professionals. Meeting with a surgeon and gaining his or her opinion can be a valuable part of your decision making process. Some surgeons will happily support athletes who want to manage their ACL rupture without surgery. Whether or not you opt to have your ACL reconstructed you should undertake a period of intense rehabilitation. Before you make a decision with regards to surgery, rehab should be carried out for at least 3, but preferably 6 months.
Initially, the goal is to reduce any swelling and increase your range of movement. When you rupture your ACL the ligament bleeds. As a result, you have significant swelling to the knee joint. Initially this swelling maybe useful to protect the joint and bring in an influx of healing chemicals. Therefore, for the first few days after the injury, you need to rest your knee but don’t worry too much about ice and anti-inflammatories.
After a few days, you can start to use ice and elevation to manage the swelling. The inflammation can restrict the range of movement in the joint and cause muscle inhibition (limit the muscles from working efficiently). However, if the swelling lingers for weeks after the injury do not be surprised. Swelling in the lower limbs can be stubborn. This is in part due to the effects of gravity and does not necessarily correlate to the injury and healing.
The primary goals are then to restore knee function, including range of movement and strength. The long-term goal is to prevent further injury and osteoarthritis. Indeed, from the very outset of an ACL injury, every programme should be tailored to you as an individual, with your own individual goals at the forefront of. your management plan. With this in mind, a physiotherapist should help you plan, implement and measure your objectives within realistic time-scales.
After an ACL rupture, I encourage my clients to move their knee and begin weight bearing as soon as pain allows. Often, clients present with a brace in situ which is a good idea in the acute phase to help control range of motion and avoid any movements which may cause additiontal stress or giving way. With a brace on, you can move your knee as much as pain allows, as long as the range of movement has not been limited by a doctor.
Strength, Agility and Proprioception
Strength, cardiovascular fitness and proprioception training are all key components of ACL rehab. These should be progressive and become more and more challenging as pain and swelling allow. Dynamic screening and testing should be ongoing throughout the rehab process. Both the client and the therapist need to be able to see and measure improvements made.
When commencing your strength training, it is really important to include all the major muscles groups in the legs. As well as your quadriceps, gluteals and calf muscles, your hamstrings are extremely important. Your hamstrings are the muscles at the back of your thigh. They help to act as a dynamic knee restraint, therefore in the absence of an ACL they play a key role in the stability of your knee.
Various authors have cited pertubation training as an important part of rehabilitation (Fitzgerald et al, Chmielweski et al. 2005, Hurd et al. 2009). They recommend that a period of perturbation training should be undertaken before you make a decision about whether to manage an ACL rupture without surgery.
Therefore, what is perturbation training? It is a neuromuscular exercise which involves balance based training combined with the application of repeated unpredictable external multidirectional forces. Furthermore, these forces vary in tempo. They aim to improve control of rapid balance and stabilising reactions and dynamic joint stability. In other words, imagine standing on one leg. During the time that you are trying to maintain your balance someone is rapidly giving you little pushes in all directions to try and throw you off balance! That is a type of perturbation training.
Most importantly, one of the biggest reasons for someone not being able to return to their sport is that they returned too soon or before their rehab had been progressed to a high enough level. Of key importance, this is true for both surgical and non-surgical candidates.
A key part of rehabilitation is incorporating sport specific drills which include agility, acceleration and cutting into your training. Strength training must be progressive and the load must increase incrementally. The neuromuscular system must learn to compensate for any ligament laxity. Therefore, if load is increased or changed too quickly the results may not be favourable.
What happens if my knee gives way, keeps swelling or gives me a lot of pain?
Certainly, if your knee continues to feel unstable or give way, despite six months of progressive, tailored rehabilitation then you many need to consider surgery after ACL rupture. Unfortunately, repetitive giving way could lead to further knee damage. It is important to note that everyone has a different response to ACL injury and no two ACL ruptures are the same.
However, if you do end up having surgery, the rehabilitation that you have done is still beneficial. Importantly, there is evidence to suggest that early rehab will reduce your risk of graft failure (Filbay et al. 2015), as well as reduce the risk of osteoarthritis. Besides, as I previously mentioned, Culvenor et al. (2019) found a loss of cartilage in the knee joint that was greater in subjects that had an early reconstruction compared with a delayed repair. Furthermore, research has shown that delayed reconstruction following a period of rehabilitation leads to better long term outcomes than early reconstruction (Filbay, 2015; Filbay, 2017; Frobell, 2010).
It is worth noting that a well known surgeon in America named Donald Shelbourne argued against this (Johnson et al. 2003). He feels that superior results are obtained when ACL surgery is offered earlier. He reported that ‘this is more frequently done in America, than in the UK where the constraints of NHS waiting lists are a factor in delayed repair’! Interpret this as you will, but I think that there are a lot of arguments for and against his opinion.
Explore all possibilities
Unfortunately, irrespective of treatment strategy a proportion of individuals will continue to experience persistent knee difficulties and unsatisfactory outcomes following an ACL rupture. Certainly, your knee biomechanics will change whether or not you have your ACL reconstructed. Therefore, educate yourself and explore all possible approaches to the management of an ACL rupture.
So will you need surgery after ACL rupture?
Not necessarily! Firstly, considerations for surgery after ACL rupture must on an individual case by case basis. As you have learnt, there are many factors that will influence the ongoing decision making process. In addition, numerous studies have recommended that after an ACL rupture, everyone should start with a period of rehabilitation. If instability and functional return are sub-optimal following rehabilitation, then surgery should be considered (Filbay, 2019; Zadro and Pappas, 2019).
In short, some of the factors that may influence whether or not you will need surgery after ACL rupture include:
- Level of and commitment to rehabilitation. Above all, this must be progressive and multifaceted to cover muscle strength and endurance, coordination, proprioception, agility and perturbation training.
- The addition of and severity of injuries to other structures of the knee
- Whether or not your knee is functionally stable. Does your knee continue to give way on you after a period of intensive rehab?
- What your individual goals are in terms of activity levels and return to sports.
- Psychological involvement.
Despite the vast number of studies carried out on ACLs (some of good quality, others not so), it still seems that the evidence is inconclusive. Admittedly, very few of these studies are large randomised controlled trials and the methodological quality is often poor. Consequently, there are still big knowledge gaps but the emerging research body is promising.
Manage every ACL rupture on an individual basis
When deciding whether rehabilitation alone is an option for you, it is key to look at the signs, symptoms and your level of function, not just the scan results. Remember that everyone must be considered on an individual basis. Certainly, your individual preferences and values must be taken into account. In addition, remember that ACL rehabilitation without reconstruction may allow a quicker return to your activities and sport.
To clarify, I am not saying that surgery is not a good option. Undoubtedly, many many people thrive after an ACL reconstruction. Moreover, every ski instructor that I know that has has their ACL reconstructed has returned to teaching. However, I am saying that surgery is not the only option. Importantly, I would highly recommend 3 to 6 months of rehabilitation before you make a definite decision. Above all, it is vital to understand that an ACL deficient joint can be a perfectly good, high functioning knee.
In conclusion, do you need surgery after ACL rupture? In short, the answer is no. To sum up, I will never tell someone not to have an ACL reconstruction. On the other hand, I will ensure that they know that it is a possibility. Certainly, I will encourage them or help them to do some research on the matter. Once you understand that undertaking a period of rehab for 3 – 6 months prior to surgery is associated with a better long term outcome, what have you got to loose by using this time for decision making?
Disclaimer: To clarify, the purpose of this blog is to provide general information and educational material relating to exercise, physiotherapy and injury management. ALP has made every effort to provide you with correct, up-to-date information. Consequently, in using this blog, you agree that information is provided ‘as is, as available’, without warranty and that you use the information at your own risk. In addition, we recommend that you seek advice from a fitness or healthcare professional if you require further advice relating to exercise or medical issues.
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