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Key questions on knee and ankle injuries (1 CPD hour)

1. How can we tell the difference between an ankle sprain and possible fracture? When should we arrange an X-ray?

Often we can’t clearly tell the difference between an ankle sprain and a fracture early on, as everything is painful and swollen and sometimes a ligament injury can be as painful as a fracture. There are a number of guidelines available to help you decide if an X-ray is warranted, for example the Ottawa ankle X-ray rules. 

Ottawa ankle X-ray rules:

Ankle X-ray is only required if there is any pain in the malleolar zone and any one of the following:

  • Bone tenderness along the distal 6cm of the posterior edge of the tibia or tip of the medial malleolus, OR –
  • Bone tenderness along the distal 6cm of the posterior edge of the fibula or tip of the lateral malleolus, OR –
  • An inability to bear weight both immediately and in the emergency department for four steps.

2. How often does actual ligament rupture occur with ankle sprains? How can we recognise it and how should it be treated?

The most commonly injured ankle ligament is the anterior talo-fibular ligament (ATFL) which is usually injured in a sudden inversion movement such as slipping off a curb or rolling the ankle in a football tackle. Complete ligament rupture in an ankle is, thankfully, rare but would be suggested by a subjective history of pain and giving way, often associated with recurrent swelling. Priorities in the early days after any ligament injury are PRICER: protection (to avoid further injury), rest from any aggravating activity (to avoid making it worse), ice (to settle inflammation), compression and elevation (to keep swelling to a minimum).

Most ligament strains will do well with exercise-based rehab guided by a physiotherapist. When symptoms such as pain and swelling fail to settle despite adequate precautions and appropriate rehab (a reasonable timeframe is 4-6 weeks) you need to ask why, as these ongoing symptoms will often suggest a more significant injury such as complete ligament rupture or cartilage damage. A second opinion from a sports physician, physiotherapist or orthopaedic surgeon is warranted. Usually they will request X-rays and a scan (ultrasound or MRI, depending on history and examination). With a clear diagnosis the treatment options can be more specific. These might include further, more focused, rehab, injections, and, where appropriate, surgery.

3. Which injuries or complications present as a persistently troublesome ankle some time after an apparently simple sprain? How can we recognise and manage these?

Most simple sprains that have been well looked after should settle within 4-6 weeks. On the other hand, a persistently troublesome ankle several weeks after an apparently simple sprain should ring alarm bells that either the injury hasn’t been allowed the right conditions to recover or that the diagnosis is more than a simple ankle sprain. Alternative diagnoses of a persistently painful or unstable ankle include synovitis, syndesmosis injury and osteochondral injury. A second opinion and appropriate imaging e.g. an MRI or ultrasound scan are warranted. Until then, ensuring optimal conditions for recovery (PRICER) is still very important. 

4. Is strapping a sprained ankle helpful?

In the initial phases of recovery, strapping is helpful to protect the ankle from further injury. This doesn’t mean that the patient can simply continue their sport while wearing strapping, but it does give them a small degree of protection from exacerbating the injury during day-to-day life. Strapping also provides some compression which can be helpful in the early stages to reduce the swelling.

Later on in the rehabilitation phase, strapping can be helpful to provide proprioceptive feedback but long-term or regular strapping can be counterproductive if it reduces the need, or motivation, to improve any further. Equally if strapping is used it must be made clear that it is only an adjunct to recovery – it is not the treatment. 

5. Which symptoms and signs warrant same-day referral after a knee injury?

There are few knee injuries that require same day referral. Examples where A&E or urgent orthopaedic review are important include an acute dislocation, a suspected fracture, and a locked knee (where the knee is stuck in a painful, usually flexed, position caused by a loose fragment or meniscal flap tear), however few knee injuries need to be referred with such urgency. Suspected fractures will need to be X-rayed and stabilised in A&E and if there is a painful, tense, haemarthrosis this can be drained for pain relief. In most other cases protection, rest, ice, compression and crutches are usually sufficient for the first few days until the next available physiotherapy, sports medicine or orthopaedic appointment. In fact, MRI is rarely done in the first 24-48 hours after injury, even in professional sport, as bleeding and oedema are too acute to give a true picture. 

6. We often see patients with persistent pain and swelling a week or two after a knee injury; they’ve usually tried RICE and NSAIDs. If there are no red flags, how long should we wait for symptoms to settle before referral? What exercises should we teach them if physiotherapy isn’t quickly available?

How long you should wait to see if symptoms settle after a knee injury depends on the degree of swelling and the patient’s ability to tolerate normal loads. If they are struggling doing everyday activities or the swelling is recurrent or persistent, then I will ask why it is not settling down, and whether there is a more significant injury than we first thought. Persistent pain and recurrent swelling are poor prognostic factors and associated with worse outcomes. They frequently indicate an underlying injury that has not settled.

Symptoms of giving way, locking and swelling are likely to indicate more significant injury and warrant an early referral. If these symptoms keep happening, further injury could also be occurring, for example giving way due to an unstable meniscus tear or a ruptured ACL resulting in further articular cartilage damage. 

If the waiting time to get to see a physiotherapist or a sports medicine specialist is long, the patient can start with some safe and simple exercises: stretching and bending to maintain range of motion, sitting on the side of the bed and straightening the leg in front of them, squatting keeping the back straight and bending the knees over the toes are all effective exercises to get started early. 

7. While most cruciate ligament injuries are dramatic and present to A&E, some can be more subtle, or are missed at first presentation and present later to the GP. What symptoms and signs should make us consider cruciate ligament injury?

ACL injuries present with a clear history of injury which, contrary to expectations, usually doesn’t involve contact with another player. Classically a footballer will say they felt their knee give way while changing direction pushing off the affected leg, a skier will catch the inside edge of their ski in soft snow and a basketball player or gymnast will describe the knee buckling beneath as they landed awkwardly from a jump on one leg. They are usually unable to play on and the knee will swell up within the first 24 hours. From then on the patient will be wary about doing anything too aggressive on their knee for fear of the knee giving way. If this happens, it is usually painful and followed by more swelling. 

8. When is an MRI scan indicated, and should GPs be able to request them? Is an MRI always requested nowadays before considering arthroscopy?

The main reasons you might request an MRI of the knee are because the patient has signs or symptoms that are strongly suggestive of an intra-articular injury that needs confirming, or because you want to exclude a potential intra-articular injury from your differential diagnosis. Either way, a simple question to ask before any scan is ‘could the results change my management of this patient’s injury?’ If the answer is yes, it would not be unreasonable to request a scan. If the scan is organised from primary care, ask the imaging department to provide the patient with a copy of the scan on CD. We can then review the pictures together, and no time is wasted in waiting for the images or new scans when the patient goes for a specialist opinion. Nine times out of 10 the sports doctor or surgeon will want to see the pictures too, especially if they are considering surgical options.

9. How do you decide when surgery is indicated for a meniscal tear? Patients hope to be symptom free as a result – how likely is this in various scenarios?

A meniscal tear on an MRI does not necessarily mean the patient needs surgical treatment. In fact, in many cases they don’t need surgery. If you’re lucky, the radiologist will try and distinguish between a degenerative tear and an acute tear. The former are usually part of a wider degenerative joint process so don’t always benefit from meniscal surgery, and the latter may not need surgery. The three ‘special questions for the knee’ (do you have locking, swelling or giving way?) can be very helpful here. If the answers are mostly ‘no, not really’ then your patient may do well with a thorough physiotherapy-led rehabilitation programme along with appropriate rest from aggravating activities until their knee strength, control and stability are back to normal.

If pain persists, or is affecting their progress through rehab, then a steroid injection can be helpful. If your patient has had appropriate physiotherapy and rest but is still experiencing locking, swelling or giving way, and the examination points strongly to the torn meniscus as the source of pain, then surgery is more likely to be successful.

10. Are knee taping or knee supports helpful in preventing or treating knee injuries? Do they have any disadvantages?

Taping does provide temporary support and, it is argued, can help to reduce the likelihood of minor injury in sport. In reality, however, tape quickly loses strength and provides little protection against the significant forces required to injure a knee ligament.

There are a variety of different types of tape on the market which vary from very stiff to surprisingly elastic. Physiotherapists will choose a tape for different reasons, occasionally for proprioceptive feedback and not always for direct support. Some tapes are very expensive and the obvious disadvantage occurs is if they are sold to the patient as a treatment in themselves without appropriate rehabilitation.

Neoprene or elastic knee supports provide very little protection. Rodeo, motocross, and wakeboarders routinely compete with a full (hard) ACL brace on, but in these sports the risks are extreme – they are certainly the exception rather than the norm.

11. How would you manage a young patient with recurrent knee dislocation? When is surgery indicated, and what are its longer-term implications?

A first episode of patellar dislocation or subluxation is usually managed nonoperatively with immobilisation in a splint and with physiotherapy, unless there is a loose fragment in the joint which may require an arthroscopy. Unfortunately, half of all acute dislocations will recur and recurrent traumatic dislocations run the risk of osteochondral damage and later arthritis so, in this group, surgery is indicated to repair the normal soft-tissue restraints or restore normal alignment.

Dr Courtney Kipps is a consultant in sports and exercise medicine at University College Hospital, London, and the Institute of Sport, Exercise & Health in London. He is also the team doctor for Harlequins Rugby Club in the Aviva Premiership.

Dr Melanie Wynne Jones, a GP in Stockport, provided the questions


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