Rotator cuff injury is a common shoulder joint disease in quinquagenarian, and its incidence rate is 17%-41%. With the advancement of shoulder arthroscopic technology (from open surgery to minimally invasive arthroscopic repair) , the treatment for rotator cuff injury under shoulder arthroscopy has gradually become the hotspot of clinical. With the help of arthroscopy, the shoulder joint lesions can be directly observed and diagnosed for determining appropriate operative method. Thus, the trauma caused by blind open exploration can be avoided. For shoulder arthroscopic surgery, a clear vision of surgical field is essential for the smooth accomplishment of operation. As applying tourniquet for hemostasis is hard to achieve, the increased bleeding during shoulder arthroscopic surgery may affect vision and prolong operation time. Therefore, finding better strategy to reduce intraoperative bleeding, clear surgical vision, shorten operation time, reduce postoperative limb swelling and promote postoperative rehabilitation deserves the common efforts of all doctors and nurses.

(1) General information. From May 2013 to April 2014, 310 cases of shoulder arthroscopic surgery were performed in our hospital. 100 cases of arthroscopic rotator cuff repair including 41 males and 59 females were screened for enrollment. The average age was (54.96±6.27) years with a range of 46 to 68 years. The course of disease ranged from 1 year to 8 years, and the mean course was (4.49±2.09) years. All patients were treated with arthroscopic repair, and rehabilitation training was conducted routinely after the operation. (2) Inclusive criteria. ① All the subjects were operated by the same group of doctors; ②All the subjects were diagnosed with rotator cuff injury (rotator cuff tear > 2 cm) ; ③The body mass index (BMI) ranged from 18.5 to 22.9; ④No subject was combined with the history of hypertension, coagulation disorders, cardiovascular disease or latent organ dysfunction. (3) Grouping and methods. The subjects were screened and enrolled based on inclusive criteria. The patients were informed of the research content and the requirements of postoperative follow-up. With the informed consent, 100 subjects were equally divided into two groups. The experimental group: the modified perfusion method with the approach as saline with epinephrine (1 mg/L) was used in shoulder arthroscopy. One of the outlet was connected with irrigation device, and the other was connected with drainage pack. The control group: the traditional perfusion with the approach as saline was used in shoulder arthroscopy. The outlets were connected with Y-tube for simultaneous irrigation. All patients were intubated under general anesthesia and in lateral position of 90° based on requirements. The backboard of operating table was lifted up to lean the upper body for 30-40°, which created an angle between the first 1/3 and middle 1/3 of operating table. The leg plates were moved downward for about 20° to create an angle between the middle 1/3 and bottom 1/3 of table. The traction apparatus was used correctly for glenohumeral joint traction to obtain a better view. The pressure pump was used in both groups for perfusion, and the pressure was set as 50 mmHg with a flow rate of 1.0 L/min to ensure a constant perfusion pressure. (4) Effect observation. We compared the red blood cell densities of irrigating solutions, the operation times, the enlargement rates of deltoid circumference, the pain levels of the 1st and 3rd postoperative days and the shoulder joint functions between two groups. The mean value of red blood cell density of irrigating solution = (total saline perfusion of joint cavity * erythrocyte number per milliliter of irrigating solution) / total saline perfusion of joint cavity. The enlargement rate of deltoid muscle circumference = (postoperative deltoid muscle circumference-preoperative deltoid muscle circumference) / preoperative deltoid muscle circumference * 100%. The pain level was evaluated by numerical rating scale (NRS) . NRS is globally the most widely used single dimension pain assessment scale. The pain level evaluation was conducted on the 1st and 3rd day after operation. The scale of 0-10 is used for the representation of different levels of pain: 0 is painless; 1-3 is mild pain (pain that does not affect sleep) ; 4-6 is moderate pain; 7-9 is severe pain (inability to fall asleep or wake up in sleep) ; 10 is intense pain. (5) Statistical analysis. The SPSS 11.0 software was used for statistical analysis. The measurement data was presented as ±s and analyzed by t-test. A P value < 0.05 was regarded as statistically significant.

Compared with those of control group, both the number of red blood cells and the operation time of experimental group was lesser. Meanwhile, the enlargement rate of deltoid muscle circumference and the swelling degree of the affected limb decreased after operation due to the significant reduction of the operation time and the perfusion volume of experimental group. In terms of patient symptoms, the pain levels of both groups on the 3rd day showed improvement compared with those on the 1st day after operation, and there was statistical difference between the pain levels of two groups on the 1st postoperative day. The pain was mainly caused by the incision and the swelling around shoulder joint. However, there was no statistical difference between the pain levels of two groups 3 days after operation.

The application of modified perfusion in shoulder arthroscopic rotator cuff repair can effectively reduce intraoperative bleeding, clear operation field, shorten operation time and relieve postoperative limb swelling, which is more conducive to postoperative rehabilitation.