Abstract: BACKGROUND: With the increase of patients with cubital tunnel syndrome, ulnar groove plasty does not affect the normal anatomical structure and distribution of the ulnar nerve, which is one of the main surgical procedures for the treatment of cubital tunnel syndrome. 3D printing combined with ulnar groove plasty can more accurately position the expansion depth and width of the ulnar groove to avoid some surgical complications. 
OBJECTIVE: To investigate the effect of 3D printing technology combined with ulnar groove plasty on nerve electrophysiology and prognosis in patients with cubital tunnel syndrome. 
METHODS: A total of 70 patients with moderate and severe cubital tunnel syndrome who were treated in Cangzhou Integrated Traditional Chinese and Western Medicine Hospital from March 2020 to March 2022 were selected as the study subjects. They were divided into two groups, with 35 cases in each group. The control group underwent traditional ulnar groove plasty. The observation group underwent 3D printing technology combined with ulnar groove plasty. The patients were followed up for 3 months. The clinical efficacy, latency, amplitude of compound muscle action potential of abductor pollicis brevis of the affected limb and ulnar nerve motor conduction velocity, grip strength on the affected side, pinch strength of the middle and thumb fingers, S-W monofilament of the little finger, two-point discrimination of the little finger, and Disabilities of the Arm, Shoulder and Hand Questionnaire score were compared between the two groups. 
RESULTS AND CONCLUSION: (1) Compared with the control group (74%), the excellent and good rate was significantly higher in the observation group (91%) (P < 0.05). (2) Compared with pre-treatment, the latency of compound muscle action potential of abductor pollicis brevis of affected limb was significantly shorter and the wave amplitude and ulnar nerve motor conduction velocity were significantly higher in the two groups after treatment. The latency was significantly shorter and the wave amplitude and ulnar nerve motor conduction velocity were significantly higher in the observation group than those in the control group (P < 0.05). (3) Compared with pre-treatment, the grip strength, middle finger and thumb pinch strength of the affected side, S-W monofilament of the little finger and two-point discrimination of the little finger were significantly decreased in the two groups after treatment. The grip strength, middle finger and thumb pinch strength on the affected side were greater, S-W monofilament of the little finger and two-point discrimination of the little finger were significantly smaller in the observation group than those in the control group (P < 0.05). (4) Compared with pre-treatment, the Disabilities of the Arm, Shoulder and Hand Questionnaire scores of the two groups were significantly reduced after treatment, and the Disabilities of the Arm, Shoulder and Hand Questionnaire scores of the observation group were significantly lower than those of the control group (P < 0.05). (5) It is concluded that 3D printing technology combined with ulnar groove plasty in the treatment of cubital tunnel syndrome can effectively improve its clinical efficacy, promote the neurophysiological recovery of patients, and enhance the function of fingers and upper limbs, which has high clinical application value.

Key words: 3D printing technology, ulnar groove plasty, cubital tunnel syndrome, neuroelectrophysiology, prognosis