Mr J is a 22 year old man who sustained a plantarflexion injury to his right foot during a fall from height at work. He was referred to his local public hospital by his general practitioner after imaging had been obtained. He was supplied with a CAM boot, advised to be non weight bearing and he was told to follow up with his local public hospital fracture clinic. Mr J did not attend this appointment as he was concerned about presenting to hospital during the first wave of the COVID-19 pandemic in Victoria. He saw his General Practitioner again eight weeks later with ongoing pain and swelling, and was subsequently referred to our private fracture clinic for an opinion. Mr J is also a type 1 diabetic with good Blood Sugar Level (BSL) control. His most recent HbA1c was 5.5%. He is not a smoker.
On examination, we noted Mr J did not have any plantar bruising, pathognomonic for an injury to the LisFranc ligament complex, but given his delayed presentation this is not surprising. He had some mild swelling, and the medial longitudinal arch of the foot was well
maintained. He was tender to palpation over the medial tarso-metatarsal joints and twisting his midfoot was moderately tender. Monofilament testing was completely normal suggesting no evidence of diabetic peripheral neuropathy.
His CT demonstrated a characteristic 'fleck sign', an avulsion fracture off the medial base of the second metatasral. There was also widening at the first/second metatarsal bases and a small comminuted fracture to the base of the medial cuneiform (see below).
This was a complex management problem. If seen acutely, this injury would commonly be treated with open reduction, internal fixation to the second tarso-metatarsal joint, stabilisation of the LisFranc ligament and inspection of often stabilisation of the first tarso-metatarsal joint
as well. However, the delayed presentation meant the window for acute fixation was lost and more appropriate surgical intervention would be a primary fusion of the first and second tarsometarsal joints, a procedure ideally avoided in young people due to the risk of transfer
arthritis later in life. Mr J was also a type 1 diabetic with an increased risk of infection and wound complications. In addition, the coronavirus pandemic was still creating a degree of uncertainty, and we are aware that diabetics have poorer outcomes if they become infected with coronavirus.
Mr J was aware of the risk of ongoing pain, development of arthritic change the the potential need for fusion surgery in the future but understandably was keen to avoid risks of surgery. After much discussion between Mr J, myself and our allied health practitioners, we decided to treat Mr J non-operatively. He was fitted with a form-fit medial arch support and commenced fully weight bearing and did very well with a rehabilitation program. Four months following his injury, he is back to his normal high-impact job, has no pain and had resumed a weight-training and exercise program the gym (prior to the second lockdown).
This is an interesting case as it suggests not all LisFranc injuries require primary fixation. There is certainly a correlation between a LisFranc ligament injury and development of arthritis at the tarso-metatarsal joints. There is currently a large randomised controlled trial in progress that is randomising patients with unstable LisFranc fractures to non-operative management, open reduction internal fixation and primary fusion (Ponkilainen 2018, below), the results of which I am waiting for with interest.
KEY LEARNING POINTS:
LisFranc ligament injuries are commonly present weeks to months after the injury as initial x-rays are often reported as normal.
If detected early and if there is evidence of widening at the metatarsal bases or evidence of instability at the tarso-metatarsal joints, these injuries are usually treated with open reduction, internal fixation.
In a delayed presentation, or if arthritis has developed, the surgical option is normally an arthrodesis (fusion) of the affected tarso-metatarsal joints.
We do not yet have a study randomising non-operative management to operative management of LisFranc injuries.
This case highlights that these injuries may be successfully managed nonoperatively
in the short-term provided patients are counselled about the risk of joint degeneration and need for fusion surgery in the future.