Objective To investigate the clinical effect of distal clavicle anatomical locking plate internal fixation com-bined with coracoclavicular ligament reconstruction in the treatment of old Neer type Ⅱb distal clavicle fractures.Methods Ninety-five patients with old Neer type Ⅱb distal clavicle fractures admitted to the Department of Emergency Trauma Surgery,Nanyang First People's Hospital from February 2019 to January 2022 were selected as the research subjects,and the patients were divided into a control group(n=50)and an observation group(n=45)according to the surgical protocols.The patients in the control group received distal clavicle anatomical locking plate internal fixation,while the patients in the observation group received distal clavicle anatomical locking plate internal fixation combined with coracoclavicular ligament reconstruction.The fracture healing time of patients in the two groups was calculated based on the criteria of blurred fracture line under X-ray,continuity of bone scab passing through the fracture line,and the absence of pain on percussion and pressure;at the final follow-up,the functional recovery of the shoulder joint was evaluated according to Herscovici efficacy criteria to calculate the overall excellent rate;before operation,at 6 months after operation,and at 12 months after operation,the subjective pain of patients in the resting state was evaluated by using the visual analogue scale(VAS),the shoulder joint function of patients in the resting state was evaluated by using the Constant-Murley scale,and the coracoclavicular distance,acromioclavicular distance,forward flexion mobility,and external rotation mobility of patients were determined by using the spiral CT.The perioperative complications such as superficial incision infection,distal fracture displacement,shoulder joint pain,vascular nerve injury,re-fracture,and bone infection were compared between the two groups.Results The absorption time of absorbable sutures of patients in the observation group was(4.12±1.28)weeks.The fracture healing time of patients in the observation group was significantly shorter than that in the control group(t=5.558,P＜0.05).The overall excellent rate of shoulder joint function recovery of patients in the observation group was significantly higher than that in the control group(x2=4.222,P＜0.05).Before operation,there was no statistically significant difference in the VAS score and Constant-Murley score of patients between the control group and the observation group(P＞0.05);at 6 and 12 months after operation,the VAS scores of the patients in the two groups were significantly lower than those before operation,while the Constant-Murley scores were signifi-cantly higher than those before operation(P＜0.05);the VAS scores of patients in the two groups at 12 months after operation were significantly lower than those at 6 months after operation,while the Constant-Murley scores were significantly higher than those at 6 months after operation(P＜0.05);at 6 and 12 months after operation,the VAS scores of patients in the observation group were significantly lower than those in the control group,while the Constant-Murley scores were significantly higher than those in the control group(P＜0.05).Before operation,there was no statistically significant difference in coracoclavicular distance,acromioclavicular distance,forward flexion mobility,and external rotation mobility between the control group and the observation group(P＞0.05);at 6 and 12 months after operation,the coracoclavicular distance and acromioclavicular distance of patients in the two groups were significantly smaller than those before operation,while the forward flexion mobility and external rotation mobility were significantly greater than those before operation(P＜0.05);the coracoclavicular distance and acromio-clavicular distance of patients in the two groups at 12 months after operation were significantly smaller than those at 6 months after operation,while the forward flexion mobility and external rotation mobility were significantly greater than those at 6 months after operation(P＜0.05);at 6 and 12 months after operation,the coracoclavicular distance and acromioclavicular distance of patients in the observation group were significantly smaller than those in the control group,while the forward flexion mobility and external rotation mobility were significantly greater than those in the control group(P＜0.05).There were no perioperative complications in patients in the two groups,such as vascular nerve injury,re-fracture,and bone infection.The total complication rates of patients in the control group and the observation group were 6.00％(3/50)and 6.67％(3/45),respectively;there was no statistically significant difference in total complication rates of patients between the control group and the observation group(x2=0.084,P＞0.05).Conclusion Distal clavicle anatomical locking plate internal fixation combined with coracocla-vicular ligament reconstruction has a significant effect in the treatment of old Neer type Ⅱb distal clavicle fractures,which can quicken fracture healing,reduce pain,and improve shoulder joint function and the three-dimensional morphology of the acromiocla-vicular joint,with few complications.