EXAMINER: Tell me what this diagram (Figure 5.1) represents and name the structures labelled 2, 3 and 5.

CANDIDATE: This diagram is a representation of the lateral aspect of the ankle showing the bony and ligamentous structures. Structure 2 is the anterior talofibular ligament, structure 3 is the calcaneofibular ligament and structure 5 is the posterior distal tibiofibular ligament.

EXAMINER: What structures are injured in a lateral ligament injury?

CANDIDATE: The mechanism is usually a rotational injury with sequential failure of the ligaments from front to back, hence the anterior talofibular ligament or ATFL is most commonly injured followed by the calcaneofibular ligament or CFL and the posterior talofibular ligament is the least frequently injured.

EXAMINER: How would you go about diagnosing a lateral ligament injury to the ankle?

CANDIDATE: In the acute setting I would expect the patient to give a history of an episode of a twisting incident resulting in significant pain and swelling. There may be a history of recurrent sprains and instability. Acutely the lateral side of the ankle anterior and inferior to the distal end of the fibula would be swollen and tender but discomfort may make it difficult to elicit definite signs of instability.

In a patient with a chronic history the clinical signs of instability would be a positive anterior drawer test or talar tilt test.

EXAMINER: Tell me more about those two tests.

CANDIDATE: The patient is examined sitting with their legs over the edge of the couch or sitting in a chair to relax the gastrocnemius soleus complex.

For the anterior drawer test the distal tibia is stabilized in one hand. The other hand is used to grasp the heel then draw the foot anteriorly in relation to the talus. Pain or excess anterior translation or a sulcus sign developing at the anterolateral corner of the ankle are signs of an ATFL injury. The other ankle must be examined for comparison. The talar tilt test involves inversion of the ankle while placing a finger on the anterolateral corner of the joint. The lack of a firm endpoint or tilt in excess of the normal side suggests instability and the CFL is considered to be injured if this test is positive.

EXAMINER: What other clinical findings may be positive in a patient with recurrent ankle sprains?

CANDIDATE: Ankle sprains are more common in patients with a cavus foot or hypermobility.

EXAMINER: If you suspect a lateral ligament injury how will you proceed in managing this patient?

CANDIDATE: The first step in management would be rehabilitation with physiotherapy, concentrating on peroneal strengthening and proprioceptive training. If the dynamic stabilizers of the ankle are well-conditioned the majority of patients recover well from a ligament injury. Bracing may be of benefit.

EXAMINER: What percentage of patients recover?

CANDIDATE: The vast majority.

EXAMINER: [That’s a bit vague] Do you know a figure?

CANDIDATE: Sorry.

COMMENT: Around 20% of patients develop symptoms of chronic ankle instability such as recurrent sprains, weakness and instability. Candidates should know this and may lose a mark.

EXAMINER: How do you determine severe injuries?

CANDIDATE: Severe extensive bruising, severe pain on moving the foot, inability to bear weight are features of a severe injury. The options for acute grade III injuries include cast immobilization or functional management. Cast immobilization involves 3 weeks in a below-knee walking cast followed by 12 weeks proprioceptive rehabilitation. Functional management involves early mobilization with external support and a protocol of rest, ice, compression and elevation. This is followed by a rehabilitation programme that comprises ROM exercises, muscle strengthening, proprioception (wobble boards) and activity-specific training.

EXAMINER: What if the patient continues to have significant symptoms despite adequate rehabilitation?

CANDIDATE: A patient that fails to recover would require investigation. I would begin with simple weight-bearing radiographs of the ankle. Other investigations include stress X-rays of the ankle and/or ultrasonography to assess the degree of ligamentous injury and if the patient is still having significant pain and swelling an MRI scan to look for additional pathology.

EXAMINER: What other conditions would you be looking for?

CANDIDATE: My differential diagnosis for an ankle sprain that does not improve would be peroneal tendon pathology such as a split tear or subluxing tendons, intra-articular pathology such as an osteochondral defect of the talus or loose body, or non-union of an anterior calcaneal process fracture.

EXAMINER: Do you know any scoring systems for chronic lateral instability?

CANDIDATE: No, sorry.

COMMENT: Karlsson score, American orthopaedic foot and ankle score (AOFAS) and the foot and ankle outcome score (FAOS).

EXAMINER: What are the surgical options for management of an isolated lateral ankle ligament complex injury in a young patient who has failed to respond to non-operative treatments?

CANDIDATE: The options fall into three broad categories. (1) Anatomic repair, (2) non-anatomic reconstruction, (3) anatomic tenodesis reconstruction.

EXAMINER: What is an anatomic repair?

CANDIDATE: Anatomic repair involves the use of endogenous ligamentous tissue to restore the ligament. This is considered in cases when adequate tissue is present.

The Broström and the ‘modified Broström’ are the most widely used procedures for anatomic repair of the lateral ligament complex.

The complication rate is lower (fewer wounds, less risk of injury to the superficial peroneal nerve and decreased incidence of degenerative joint disease) compared to non-anatomical reconstructions with minimal effect on subtalar movement and a quicker rehab.

Failures have been attributed to a variety of factors, including generalized ligamentous laxity, poor tissue quality, previous surgical repair, long-standing instability, and cavo-varus deformity.

EXAMINER: What do you mean by a non-anatomic reconstruction (check-rein procedure)?

CANDIDATE: Non-anatomic reconstruction does not replicate the normal course and anatomy of the ATFL and CFL.

Examples of non-anatomic reconstructive procedures include the Chrisman–Snook procedure, the Watson-Jones procedure and the Evans reconstruction, all utilizing the neighbouring peroneus brevis tendon to restrict motion without repair of the injured ligaments.

EXAMINER: What do we mean by anatomical reconstruction?

CANDIDATE: These procedures utilize autogenous tendon grafts such as semitendinosus, gracilis or plantaris that are rerouted in such a way as to replicate the anatomic positions of the ATFL and CFL origin and insertion sites.

EXAMINER: Are intra-articular lesions common in this group?

CANDIDATE: Various studies have found chondral injuries in a significant proportion of patients with chronic ankle instability. In one study associated intra-articular pathology amenable to arthroscopic treatment was identified in 83% of patients undergoing Brostrom repair [1]. Arthroscopic abrasion, curettage, drilling or microfracture can be used for the OCLs.

EXAMINER: A patient asks how successful a ligament repair will be, what will you tell them?

CANDIDATE: I would expect a successful result in approximately 80% of patients.

EXAMINER: What are the reported results of using a free hamstring graft?

CANDIDATE: The reports are good but there are some reports of weakness of knee flexion beyond 70°, particularly when both gracilis and semitendinosus tendons are harvested.

COMMENT: This ligament reconstruction can be performed through short incisions, effectively making it a minimally invasive technique. The harvested graft (semitendinosus or gracilis) is secured in a tunnel in the calcaneum using interference or biotendinosis screws then passed through a tunnel in the fibula and finally secured under tension into a further tunnel in the talus. This leaves the stabilizing evertor muscles intact together while reconstructing the ATFL and CFL and so may also be considered to be an anatomic repair.

The selected fixation device should be secure enough to maintain appropriate graft tension intraoperatively to support healing and potentially allow for early joint motion

EXAMINER: Thank you.

EXAMINER: Describe the findings on this X-ray (Figure 5.2).

CANDIDATE: This is an AP weight-bearing radiograph of a left ankle showing narrowing of the joint space and some subchondral sclerosis. There is also evidence of a previous fibula fracture superior to the syndesmosis and varus angulation of the ankle. These findings are consistent with post-traumatic arthritis.

EXAMINER: What are the most common causes of arthritis of the ankle?

CANDIDATE: The most common cause of ankle arthritis is post-traumatic arthritis. Other causes include inflammatory, neuropathic and septic arthritis. Primary osteoarthritis is thought to be relatively uncommon.

COMMENT: In a recent epidemiological survey, the onset of ankle osteoarthritis was attributable to a previous rotational fracture (37.0% of cases), recurrent sprains (14.6%), a single sprain (13.7%), pilon fracture (9.0%), tibial shaft fracture (8.5%) and osteochondral lesion of the talus (OLT) (4.7%) [2].

EXAMINER: How is this patient likely to present?

CANDIDATE: The patient is likely to complain of pain, restriction of movement, deformity and difficulty in undertaking activities of daily living (ADLs).

EXAMINER: Are you aware of any classification systems for arthritis of the ankle?

CANDIDATE: No, I am not aware of any classification systems specific to the ankle.

COMMENT: The Kellgren and Lawrence Radiographic Criteria can be used [3].

EXAMINER: The X-ray you have been shown belongs to a 42-year-old manual worker who had an ankle fracture 7 years ago that was managed non-operatively. Describe your management strategy for this patient.

CANDIDATE: I would first want to take a full history and examine him, then obtain a lateral standing radiograph.

EXAMINER: Tell me about the management options available for ankle arthritis.

CANDIDATE: I would start with conservative measures and the options include NSAIDs, activity modification, footwear modification with a cushioned sole and rocker bottom shoe, an ankle brace or AFO, intra-articular steroid injection or visco-supplementation and physiotherapy.

PRP injections have been used in patients with osteoarthritis.

One study reported a strong positive effect on pain and function after four PRP injections at weekly intervals [4].

EXAMINER: What surgical options are available?

CANDIDATE: There are two types of surgical option available, those aimed to ‘buy time’ or provide temporary relief and definitive treatments. The temporizing measures are debridement of the joint which can be performed arthroscopically or open depending on the extent of disease and should be aimed at treating identifiable causes of symptoms such as removing loose bodies, trimming anterior osteophytes which may give impingement symptoms, or debriding loose areas of articular cartilage and areas of synovitis. The other option is distraction arthroplasty [5].

The definitive surgical options are ankle fusion or ankle replacement.

EXAMINER: What about arthroscopic debridement and osteophyte resection?

CANDIDATE: This may be helpful in patients with mild arthritis with a large osteophyte restricting motion or causing painful impingement at the extremes of motion. Rest pain is unlikely to be relieved. This operation is unlikely to be successful with this particular patient.

EXAMINER: What about distraction arthroplasty?

CANDIDATE: Distraction arthroplasty can be used on several joints including the hip, knee and ankle to preserve the joint space and decrease the weight-bearing load by using an external fixator to distract the respective joint. This is usually combined with an attempt at articular cartilage repair such as subchondral drilling or microfracture. Results of motion distraction are better than fixed distraction. Continuous joint movement is essential for cartilage regeneration and reduces overloading protecting fibrocartilage regeneration. Distraction arthroplasty is best suited for post-traumatic ankle osteoarthritis.

EXAMINER: Would you offer him distraction arthroplasty?

CANDIDATE: My concerns about offering him distraction arthroplasty are that he is a young patient with a physical occupation. The distraction device needs to be kept in place for at least 3 months, which is a significant treatment commitment. Ankle function declines following joint distraction such that at 5 years around 50% of patients will either have gone on to ankle arthrodesis or replacement. Due to the relatively small number of studies with only level 4 evidence and no long-term follow-up I would rather offer him ankle arthrodesis [6].

EXAMINER: Isn’t fusion an outdated treatment now that ankle replacements are available?

CANDIDATE: No, total ankle replacements are not suitable for every patient and ankle fusion is still considered the ‘gold standard’, especially so for younger patients with severe post-traumatic ankle arthritis.

EXAMINER: So which patients should be considered for ankle replacement surgery?

CANDIDATE: Ankle replacement surgery could be considered in low-demand patients over the age of 60 years who have inflammatory arthritis or osteoarthritis. Bilateral disease or arthritis affecting adjacent joints is a relative indication. Contraindications include younger, more-active patients, significant ankle instability, particularly deltoid ligament insufficiency, significant deformity, especially varus or valgus of more than 10°, peripheral vascular disease, a poor soft-tissue envelope, marked osteoporosis or avascular necrosis of the tibial plafond or talar dome.

EXAMINER: Do you know anything about the types of ankle replacement available?

CANDIDATE: The earlier designs involved a two-component design such as the Agility total ankle replacement, which required fusion of the distal tibiofibular joint. Most modern designs are three-component uncemented mobile bearing prostheses.

EXAMINER: A patient wants to know how long an ankle replacement will last. What will you tell them?

CANDIDATE: The 10-year survival is about 85%, but there are fewer data available compared to knee and hip replacements [7–10].

EXAMINER: The 42-year-old patient we began by discussing wants an ankle replacement. What would you tell him?

CANDIDATE: He is a young patient in a manual job. He wouldn’t be a candidate for total ankle replacement and I would explain to him that if his symptoms have not been controlled by non-operative measures then he requires definitive surgical treatment and an ankle fusion would be a better option for him.

EXAMINER: He still wants a replacement, as he is keen to get back to hill walking and sports and doesn’t want a stiff ankle. What will you tell him now?

CANDIDATE: He would be at risk of early failure with an ankle replacement due to his age and level of activity. Postoperative complications of total ankle replacement include infection, loosening, progressive intracomponent instability or deformity, subsidence and polyethylene failure.

A fusion would provide a stable, pain-free ankle that would allow him to return to the majority of activities that he wishes to do. I would explain that many patients return to sports after ankle fusion. I would also explain that an ankle fusion would only sacrifice the residual movement that he has at his ankle joint and that his subtalar, midfoot and forefoot movements would still be present.

EXAMINER: What position should his ankle be fused in?

CANDIDATE: The ankle should be fused in 5° of hind-foot valgus, 10° of external rotation and the foot should be plantigrade.

EXAMINER: What complications will you warn him about?

CANDIDATE: Infection, wound healing problems, neurovascular injury, DVT/PE, delayed union, malunion, non-union, hardware failure and the risk of exacerbating or developing arthritis in other joints (subtalar joint).

EXAMINER: Anything new on the horizon?

CANDIDATE: Ankle osteochondral allograft reconstruction involves replacing all or a large part of the arthritic ankle joint with a cadaveric bulk osteochondral allograft. Although in theory this procedure is a potentially desirable option for a young patient with advanced ankle arthritis, reported results suggest a high failure rate.

EXAMINER: Thank you.

EXAMINER: Please have a look at this radiographic print and tell me what you see. (See Figure 5.3.)

CANDIDATE: This is an AP radiograph of a forefoot. There is a hallux valgus deformity with subluxation of the second metatarsophalangeal joint and destructive change of all the metatarsophalangeal joints. There may be deformities of the lesser toes and I would like to see a lateral view to clarify this.

EXAMINER: A lateral view would be very helpful. What do you think is the underlying diagnosis?

CANDIDATE: The changes suggest that this is an inflammatory polyarthropathy such as rheumatoid arthritis.

EXAMINER: Could it be anything else?

CANDIDATE: The appearances could be secondary to a neuropathic process.

EXAMINER: What might be the commonest neuropathic process that could cause these appearances?

CANDIDATE: A peripheral neuropathy such as that associated with diabetes mellitus would be the commonest.

EXAMINER: How would you confirm your diagnosis?

CANDIDATE: A detailed history would be most informative. Specifically, I would enquire about pain, swelling and sensory alteration.

EXAMINER: OK. This lady gives a clear history of progressive, painful, bilateral small joint swelling and post-immobility stiffness. She has great difficulty finding comfortable shoes and describes the feeling of walking on pebbles. She is not aware of any diabetes or sensory loss. What are your thoughts at this stage?

CANDIDATE: This appears to be an inflammatory arthropathy.

COMMENT: Candidates may be asked about the revised diagnostic criteria of the American College of Rheumatology (ACR)/European League against Rheumatism (EULAR).

This requires confirmed synovitis of one or more joints, with absence of alternative explanation for the synovitis, and achieving a score of 6 or greater out of 10 from domains including:

EXAMINER: Yes. Her feet are making her life pretty miserable and she would like you, as an orthopaedic surgeon, to do something to make them better. Your examination finds marked active synovitis and plantar tenderness under the metatarsal heads as well as a minimally correctable hallux valgus. There is some hammering of the lesser toes with a cock-up deformity of the second toe. Sensation and perfusion appear good. What are you going to do?

CANDIDATE: First, I would want to know if she is known to a rheumatology service and has had any attempt at non-operative intervention.

EXAMINER: She has never seen a rheumatologist and has never sought help for her feet other than from you via her GP.

CANDIDATE: I would advise her that operations are helpful but that she should be formally assessed by a rheumatologist to confirm the diagnosis and achieve disease control using DMARDs. I would also advise review by the local podiatry and/or orthotics service as simple footwear modification may be all that is necessary to control her symptoms.

COMMENT: The key buzz phrase to mention (if appropriate) is that patients with rheumatoid arthritis require a (contemporary) multidisciplinary approach to their management. This may also include involvement of vascular surgeons, occupational therapists and physiotherapists.

EXAMINER: I think that is appropriate advice at this stage. However, she returns to you a year later. Her synovitis is controlled by biological agents, but she has not found insoles and modified shoes helpful. How would you manage her at this point?

CANDIDATE: I would suggest surgery in the form of forefoot reconstruction. This consists of excision of the lesser metatarsal heads, correction of lesser toe deformities and excision or fusion of the first metatarsophalangeal joint.

EXAMINER: Why?

CANDIDATE: This is a proven intervention with good results.

EXAMINER: How good?

CANDIDATE: More than 80% of patients report significant improvement.

EXAMINER: Would you fuse or excise the first metatarsophalangeal joint?

CANDIDATE: I would be guided by her age and functional demand in combination with the quality of the soft-tissue envelope of her foot. I would prefer to fuse the joint as I believe this aids maintenance of gait but, in a low-demand patient, excision is associated with reduced complications and more rapid rehabilitation [11].

EXAMINER: How would you secure the arthrodesis?

CANDIDATE: I would use an oblique compression screw augmented by a dorsal locking plate as biomechanical and clinical studies have shown this to be the most reliable method.

EXAMINER: Would you always excise the lesser metatarsal heads in a patient of this age who now appears to have their disease under control?

CANDIDATE: No. It would be appropriate to perform shortening osteotomies such as Weil osteotomies to preserve the metatarsal heads if they are not badly diseased.

EXAMINER: Surely that just prolongs the procedure and increases the risk of complication?

CANDIDATE: Yes, but it is very difficult to salvage a rheumatoid foot without metatarsal heads if the disease progresses in subsequent years.

EXAMINER: Tell me about the principles of surgery in rheumatoid arthritis.

CANDIDATE: Surgery is indicated when symptoms and/or deformity are uncontrolled or getting worse. The overall objective is to produce a stable, plantigrade foot. Arthrodesis is the favoured procedure, but the risk of complications as a result of osteopenia, reduced vascularity and immunosuppression are to be borne in mind.

EXAMINER: What steps can a surgeon take to minimize the risk of complications?

CANDIDATE: A drug history is vital, as patients may well be on medications such as antiplatelet therapy, steroids or immune-modifying drugs which may have to be stopped or modified perioperatively.

Biological agents should be stopped in the run up to surgery and not resumed until there is good evidence of postoperative healing. It should go without saying that meticulous handling of soft tissues is necessary. Incisions must be planned with care, both to maintain adequate skin bridges and to ensure satisfactory wound closure if significant deformities are being corrected.

EXAMINER: How long would you stop biological agents for?

CANDIDATE: Two weeks pre- and postoperatively [12,13].

EXAMINER: What about other disease-modifying anti-rheumatic drugs? Which other ones would you stop?

CANDIDATE: Studies have shown that there is generally no need to stop drugs such as methotrexate or leflunomide.

COMMENT: Perioperative management of RA medications [14]:

EXAMINER: I would like to backtrack a bit. Would you alter your management if she also had signs and symptoms of hindfoot arthritis?

CANDIDATE: Generally, I would plan to address the most symptomatic area first. However, a less symptomatic and fixed hindfoot deformity should be corrected before proceeding to the forefoot. Flexible hindfoot deformity could be left until more symptomatic.

EXAMINER: Which hindfoot joints are most commonly affected in rheumatoid arthritis?

CANDIDATE: The talo-navicular joint is most commonly affected, followed by the subtalar and calcaneocuboid joints.

EXAMINER: Can you outline the arguments for and against isolated talo-navicular fusion in RA?

CANDIDATE: Isolated talo-navicular fusion is a lesser procedure than triple fusion for both patient and surgeon and effectively eliminates hindfoot motion. Historically, a non-union rate of up to 37% has been reported, although more recent studies suggest the non-union rate using contemporary fixation is much less. A triple arthrodesis is more reliable and allows greater deformity correction.

EXAMINER: Thank you.

EXAMINER: These are photographs of the left foot of a 20-year old man (Figure 5.4). Describe them.

CANDIDATE: These clinical photographs show the anterior, medial and posterior views of a left foot with a cavus deformity. The hindfoot is in varus and there is a high medial arch. There doesn’t appear to be any significant clawing or abnormality of the toes. There is some shortening of the medial column of the foot and I can’t see any obvious callosities beneath the metatarsal heads.