Atypical musculoskeletal manifestations on flexor hallucis longus tendon of gout causing tarsal tunnel syndrome in diabetic patients: A case report

An Update on Posterior Tarsal Tunnel Syndrome

Posterior tarsal tunnel syndrome (PTTS) is an entrapment neuropathy due to compression of the tibial nerve or one of its terminal branches within the tarsal tunnel in the medial ankle. The tarsal tunnel is formed by the flexor retinaculum, while the floor is composed of the distal tibia, talus, and calcaneal bones. The tarsal tunnel contains a number of significant structures, including the tendons of 3 muscles as well as the posterior tibial artery, vein, and nerve. Focal compressive neuropathy of PTTS can originate from anything that physically restricts the volume of the tarsal tunnel. The variety of etiologies includes distinct movements of the foot, trauma, vascular disorders, soft tissue inflammation, diabetes mellitus, compression lesions, bony lesions, masses, lower extremity edema, and postoperative injury. Generally, compression of the posterior tibial nerve results in clinical findings consisting of numbness, burning, and painful paresthesia in the heel, medial ankle, and plantar surface of the foot. Diagnosis of PTTS can be made with the presence of a positive Tinel sign in combination with the physical symptoms of pain and numbness along the plantar and medial surfaces of the foot. Initially, patients are treated conservatively unless there are signs of muscle atrophy or motor nerve involvement. Conservative treatment includes activity modification, heat, cryotherapy, non-steroidal anti-inflammatory drugs, corticosteroid injections, opioids, GABA analog medications, tricyclic antidepressants, vitamin B-complex supplements, physical therapy, and custom orthotics. If PTTS is recalcitrant to conservative treatment, standard open surgical decompression of the flexor retinaculum is indicated. In recent years, a number of alternative minimally invasive treatment options have been investigated, but these studies have small sample sizes or were conducted on cadaveric models.

Tarsal Tunnel Syndrome: An Ultrasound Pictorial Review

Tarsal tunnel syndrome may be idiopathic or may be caused by various conditions: bone disease, thickening of the retinaculum, hematoma, or iatrogenic nerve damage; tendinopathy or tenosynovitis; the presence of supernumerary muscles such as an accessory soleus, peroneocalcaneus internus, or accessory flexor digitorum muscle; bone or joint disorders; expansile tumors or cysts; and venous aneurysm or kinking of the tibial artery. The purpose of this article is to describe and illustrate most of the causes of tarsal tunnel syndrome, as diagnosed by ultrasound, which is a practical, inexpensive method.

Multiple gouty tophi in the head and neck with normal serum uric acid: A case report and review of literatures

BACKGROUND

Gouty tophus is rarely reported in the head and neck areas. To the best of our knowledge, this is the first report on multiple gouty tophi in the head and neck with normal serum uric acid (SUA) levels.

CASE SUMMARY

We report a case of multiple gouty tophi in the nasal dorsal and auricle regions with normal SUA levels. The patient was admitted to the hospital with a chief complaint of recurrent nasal swelling and pain for 3 years, which was aggravated for 3 d. The patient’s SUA level had been regularly reviewed in the outpatient department and had been successfully controlled for several years. Resection of the nasal masses was performed. Cartilage from the right ear cavity was used to repair the nasal defects. The pathological report confirmed a nasal gouty tophus. No recurrence or deformity was found after a 1 year follow-up.

CONCLUSION

Normal SUA cannot completely negate the diagnosis of gouty tophus, especially in some rare regions.

Tarsal tunnel syndrome: current rationale, indications and results

Tarsal tunnel syndrome (TTS) is a neuropathy due to compression of the posterior tibial nerve and its branches. It is usually underdiagnosed and its aetiology is very diverse. In 20% of cases it is idiopathic. There is no test that diagnoses it with certainty. The diagnosis is usually made by correlating clinical history, imaging tests, nerve conduction studies (NCSs) and electromyography (EMG). A differential diagnosis should be made with plantar fasciitis, lumbosacral radiculopathy (especially S1 radiculopathy), rheumatologic diseases, metatarsal stress fractures and Morton’s neuroma. Conservative management usually gives good results. It includes activity modification, administration of pain relief drugs, physical and rehabilitation medicine, and corticosteroid injections into the tarsal tunnel (to reduce oedema). Abnormally slow nerve conduction through the posterior tibial nerve usually predicts failure of conservative treatment. Indications for surgical treatment are failure of conservative treatment and clear identification of the cause of the entrapment. In these circumstances, the results are usually satisfactory. Surgical success rates vary from 44% to 96%. Surgical treatment involves releasing the flexor retinaculum from its proximal attachment near the medial malleolus down to the sustentaculum tali. Ultrasound-guided tarsal tunnel release is possible. A positive Tinel’s sign before surgery is a strong predictor of surgical relief after decompression. Surgical treatment achieves the best results in young patients, those with a clear aetiology, a positive Tinel’s sign prior to surgery, a short history of symptoms, an early diagnosis and no previous ankle pathology.

Cite this article: EFORT Open Rev 2021;6:1140-1147. DOI: 10.1302/2058-5241.6.210031