A 34-year-old man consulted for pain with paraesthesia on the ulnar border of the right hand and fourth and fifth fingers for two weeks after a tennis tournament. He presented diffuse oedema in the volar aspect of the ulnar area of the wrist and hand, with positive Tinnel over the pisiform. Radiology and ultrasound were normal. After infiltration of a corticoid with local anaesthetic, he was immobilised with a wrist brace in neutral position. The neurophysiological study showed a compressive neuropathy of the ulnar nerve in Guyon's canal. The patient received symptomatic treatment with cryotherapy, orthosis, analgesics, vitamin B complex and physiotherapy. Computerised Axial Tomography (CAT) of the wrist, requested due to persistent pain at nine months, showed a pseudarthrosis of the unciform process of the hooked bone, with a large fragment. He underwent surgery by palmar approach, dissection of the ulnar neurovascular bundle, cross-linking of the pseudarthrosis bed and osteosynthesis with two 1.5mm diameter Compact Hand titanium screws (Synhes®). He maintained an antebrachial splint, including the fingers, for three weeks, after which he began physiotherapy. Four months after surgery, the patient was symptom-free, except for hypoaesthesia of the fourth finger, with full mobility, recovered strength and returned to work (strength) and sporting activities. The CT scan at two months and the X-ray at three months showed a partial fusion. A new CT scan at four months showed complete union.