Objective To explore the clinical effect of the semishoulder arthroplasty in the treatment of humeral head necrosis.Methods Twenty patients with head necrosis of the humerus in first hospital affiliated to army medical university from February 2008 to January 2018 were collected

including 8 cases of males

12 cases of females

7 cases of left shoulder and 13 cases of right shoulder. The patients were aged from 45 to 83 years old

mean (67.40±5.06)years old.All patients were followed up for at least 6 months

the anterior flexion angle

abduction angle

external rotation angle and internal rotation angle of shoulder joint were measured

the function of shoulder joint was evaluated by ASES

UCLA

SST

and VAS

and the imaging examination was conducted. Results All patients were followed up for 6 to 37 months after surgery

with average (18.50±5.31) months，2 patients presented mild pain during shoulder joint activity

1 patient presented brachial plexus nerve damage

but returned to normal 3 months after surgery.No complication happened. X-ray reexamination showed good position and angle of the prosthesis during the followup period. The preoperative anteflexion angle

angle of outreach

swing angle and swing angle of the shoulder joint were respectively (55.24±8.21)°

(42.58±6.21)°

(12.95±2.74)°

(17.79±3.65)°

the last followup were respectively(120.76±13.15) °

(103.08±10.54) °

(33.51±3.14) °

(50.10±7.25) °

the differences were significant(P<0.01); The preoperative ASES score

UCLA score

SST score

VAS score of the shoulder joint were respectively（38.24±5.21）

（12.58±3.93）

（3.25±1.42）

(6.79±1.65)

the last followup were respectively（75.74±9.69）

（33.08±4.5）

（9.11±1.85）

(1.45±0.24)

the differences were significant(P<0.01)．Conclusion Artificial semi-shoulder replacement for the treatment of humeral head necrosis can significantly improve the range of limb function

relieve the pain symptoms of patients and improve patients quality of life

which has excellent and good shoulder function rate and fewer complications.