TARSAL BOSS

Welcome to ‘my foot pain series 3′

Dealing with the midfoot or midtarsus, where the presence of the tarsal boss or dorsal spur arises can make management  tricky and so self-help is more practical in the first place. The latter is also preferable for the patient but they need to understand what the condition is and some of its other problems. Some academic resources on Clinician Portal is provided with additional references for professionals. You can see the condition under Footlocker as foot bump on the top of the foot.

The condition

A condition that causes pressure on top of the foot due to changes around the middle bones also know as the tarsus. Conditions associated with the bump include joint surface damage (arthrosis). Tendon or nerve pain that arise with the hard bone bump. Look at the picture of a female foot to identify with the problem (source: Bawa 2016) .

Naming the condition Other names given to this condition are dorsal spur, exostosis, tarsal boss. This latter term is quite apt as in the Collins dictionary boss can mean a knob or stud or other circular rounded protuberance.


Recommended source and further reading

https://footeducation.com/tarsal-boss/

My five star ranked link for Foot Education is recommended. It is impartial with some good writing and knowledge behind the website. Tarsal Boss‘: Edited by Judith Smith MD  October 24, 2017. Previously Edited by Stephen Pinney, MD mf/ 9.23.19


Academic papers (Clinician Portal)

I like to source recent papers and provide  balance between podiatry and orthopaedic seems a good approach.

Lui 2017 (click on the link for the full paper)

Abstract: Dorsal boss of the foot also known as “tarsal boss,” “dorsal exostosis,” and “humped bone” is a bone spur that grows from one of the intertarsal or tarsometatarsal joints. It can occur with or without arthritis of the underlying joints. Surgery is indicated if the symptoms do not respond to conservative treatment. Excision of the dorsal boss with or without fusion of the underlying joint is the operative treatment of choice. We report an arthroscopic approach of resection of the dorsal exostosis. Arthroscopic arthrodesis if indicated can be performed through the same portals.

Bawa 2016 foot bump (click on the link for the full paper)

Abstract: A retrospective case series testing the efficacy of surgical resection of the dorsal exostosis deformity of the metatarsocuneiform joints was performed. Surgery was performed in 26 consecutive patients (28 feet), in whom previous conservative therapy had failed. All 26 patients had bursitis at the level of the dorsal exostosis deformity. The patients were separated into 2 groups: group 1, those with bursitis and neuritis before surgery (n 1⁄4 13; 46.4%), and group 2, those with bursitis without neuritis (n 1⁄4 15; 53.5%). Both groups were evaluated using an 11-point visual analog scale administered preoperatively and 1 year postoperatively. The mean pain rating in the patients with neuritis and bursitis before surgery (7.31  2.8) and in those with bursitis without neuritis (6.67  3.4) had both decreased to 0 at 6 months and 1 year after surgery. After surgery, 7 patients (25.2%) experienced neuritis. Of these 7 patients, 4 (57.1%) had continuation of neuritis that was present before surgery and 3 (42.9%) had an onset of neuropraxia that was secondary to the surgery itself. This might have resulted from retraction of the nerves during spur removal. Eventually, all the cases of neuritis resolved. One patient (3.6%) experienced regrowth of their dorsal exostosis deformity, 1 (3.6%) developed an abscess at the surgical site, and 1 (3.6%) developed pain elsewhere at the Lisfranc joint. All patients were subsequently treated at our institution and were pain free and had returned to full activity within 1 year. These results suggest that resection of the dorsal exostosis deformity of the metatarsocuneiform joints is an effective surigical procedure for patients with this deformity.


 

The following differential diagnoses can be considered

  • Arthrosis, or joint surface damage.
  • Tendon pain, often associated with overuse
  • Nerve pain
  • Ganglion
  • Bursa
  • Hard bone bump also known as a spur.
  • Gout has been recorded but this is not that common in the midfoot so it can be set at a lower priority.

First of all, look at the appearance. The top of the foot will have a bump above the arch and it can be tender to touch, worse in some shoes. If we look at an x-ray it is easier to see what is happening. Picture: Dr Van Dalen

The main aim is to take away pressure so it comes down to shoe selection and what you can do to the shoe to make matters more comfortable. Remember that the lacings of shoes can be too tight, or the cut of the shoe places a  too much pressure where it is tender.


  Self-help remedy

Footlocker provides some further information [click here]

 


Still no better?

Chronic problems: What happens if the problem becomes chronic; that is keeps coming back and causing niggly symptoms.

Superficial nerve
First of all, tap the top of the foot and if the sensation is tender or even electrical in nature you may well have a nerve the runs over the bump. This is the dorsal medial superficial nerve. A tongue twister at best. Just a word of warning. If the nerve is compressed over the bone and symptoms do deteriorate it is likely the nerve will thicken and easily repeat those symptoms without much provocation. Protection and shoe selection is vital.

Bursitis
Small sacs filled with lubricating fluid reduce friction and irritation between the bone, tendons, muscle, and skin near your joints but the development of a bursitis can cause pain. It might be worth thinking about having a one-off steroid injection is the area is soft swollen and not thought infected. Ganglion and bursae are similar although actually are derived from different tissues. Ganglia are easier to remove the fluid from. NB antibiotic should not be used with good reason or evidence of their need.

Seeking surgery
Not perhaps where you want to go but sometimes surgery is the best way to resolve matters permanently. You should seek out a foot surgeon (podiatric or orthopaedic). Check they are registered with the HCPC or GMC. Here’s a summary of my own experience and some of the things that I would tell a patient before surgery.

Surgery

  • The scar line is important so where the skin is cut can be a problem.
  • The bone is shaved down. If you are under 20 there is a chance that reoccurrence can arise because young people can regenerate bone. This might happen more readily if there is greater movement after surgery as it can all start again, or insufficient bone is removed.
  • Although bump surgery can be very effective, wounds can take time to heal. You can expect skin to heal from 10-21 days before it is relatively strong to get back into shoes. Sensations may vary after surgery, numbness or local sensitivity.
  • The good news is that the surgery works and it is effective.
  • The bad news is that the joint may be less stable and if you have existing degeneration in the joint movement made by making the joint freer may worsen matters. This means a second surgery to stiffen and fix the problem. This does not happen very often.

Stiffening the toe?
 This means that a screw or metal brace (plate) is placed across the joint. On balance real problems arise from loss of movement around the joint  from this procedure.

So why do I need to have it stiffened?
The spur actually holds the joint stable. As the surgery involves shaving off the spur the two ends might now move. After surgery, and once the foot has healed you can start to try out shoes again. It makes sense to allow up to six months for all shoes. Of course there might be a pair you still cannot use but on the whole you comfort and the original problem will have disappeared.


 

Thanks for reading ‘Tarsal Boss’ written by David Tollafield. Published 15 October 2019. Busypencilcase Communication Ltd.