观察一种新型的改良钥匙孔固定术治疗肱二头肌长头腱（long head of biceps，LHB）断裂的疗效。

自2015年4月至2017年7月南京中医药大学附属医院对9例有肌力下降和鼓眼畸形的LHB断裂的患者行钥匙孔固定术结合髓外皮质骨微型钢板悬吊式固定，手术前后采用视觉模拟评分（visual analogue scale/score，VAS）、肘关节旋后和屈曲肌力、美国加州大学肩关节评分（the university of California at Los Angeles shoulder rating scale，UCLA）和美国肩肘外科协会评分（American shoulder and elbow surgeons＇form，ASES）等评估手术效果。

9例LHB断裂患者均获得术后1年随访，术后1年所有患者旋后和屈肘肌力Ⅴ级，肩痛明显减轻，UCLA和ASES评分优良率均为100%，VAS、UCLA和ASES评分差异均具有统计学意义，术后1年无钢板脱落及固定失效发生。

改良钥匙孔固定术治疗LHB断裂具有操作难度小、安全性高、固定可靠等优点，值得临床推广。

One third of the proximal long head of biceps (LHB) strides into the shoulder joint at a large angle, and its pathological changes are the common cause of shoulder pain. The pathological changes of LHB include tendinitis, tendon abrasion, SLAP injury, partial or complete rupture. Isolated LHB lesions are rare, often accompanied by rotator cuff tear or subacromial impingement. Tenodesis is a reliable and effective method for the treatment of LHB lesions. Many surgical methods have been reported for long head tendon fixation of biceps brachii muscle, including open, small incision or complete endoscopic surgery, high or low tendon fixation, bone tunnel fixation, soft tissue fixation, key hole fixation, anchor fixation or interface screw fixation, etc.. In 2011, Siebenlist et al. reported a new method of fixing LHB by suspending a mini-plate on the inner surface of the proximal humerus cortex, and obtained better biomechanical results in a short time. However, we believe that this fixation technique only relies on single cortical bone fixation. Tendons only contact with the surface of the cortex and the contact area is small, which may be harmful to tendon healing. Because the technique needs to pull the guide needle through the opposite side of the soft tissue when reversing the steel plate, there is a risk of axillary nerve injury. Therefore, we improved the method and combined key-hole technique to transfer the mini-plate placed in the medulla to the ipsilateral cortical bone surface. It was used in 9 cases of LHB rupture with pop-eye deformity and decreased muscle strength. The short-term effect was satisfactory.

I. General information.From April 2015 to July 2017, 9 patients with pop-eye deformity caused by rupture of LHB and decreased elbow flexion strength were treated with modified key-hole suspension fixation. Among the 9 patients, 8 were male and 1 was female, all were manual workers; aged 43-65 years; 9 were right shoulder; 6 were treated after complaining of shoulder pain and bouncing after lifting heavy objects; 3 were right upper limb pop-eye deformity suddenly without obvious cause for long-term shoulder pain; all patients complained reduced elbow flexion strength. Operative indications: (1) Simple rupture of LHB, without any other disease of shoulder joint; (2) Patients complaining of pain, affecting life and demanding improvement of symptoms; (3) Reduced elbow flexion strength, patients demanding improvement of elbow flexion strength. Relative contraindication of operation: arthroscopic operation is recommended if there are other diseases of shoulder joint. II. Operative methods.The operation was performed under general intravenous anesthesia. The patient was placed in a beach chair position. The affected limbs were placed in the abduction of 20 degrees, elbow flexion of 90 degrees and forearm supination of 90 degrees. The incision starts at 2 cm from the lateral coracoid process and runs laterally and distally along the anterior edge of deltoid muscle, which is about 5 cm in length. The cephalic vein was pull ed medially.The tendon sheath of biceps brachii long head was opened under direct vision.The torn long head of biceps was easily found (sometimes contracture of the torn end to the deep layer of pectoralis major tendon) . After electrocoagulation of the branches of the anterior humeral circumflex artery, a 4.0 mm drill was drilled vertically into the medullary cavity in the proximal cortex of the humerus along the distal extension line from the intertubercular sulcus and the upper edge of the pectoralis major tendon, slightly to the head. The second hole was then drilled with a 4.0 mm bit at the proximal 2 cm of the upper edge of the first drill, slightly toward the tail. The torn ends of tendonwere trimmed and the biceps brachii tendon was tensioned at elbow flexion to of 90 degrees, make the junction of tendon abdomen level with the lower edge of pectoralis major tendon. The stump of tendon was excised parallel to the proximal hole, and the end of tendon was woven with 2 No. 5 ethibond suture of 2.5 cm. Put the curved hollow guide through the bottom hole and through the top hole, extend the guide wire loop in the guide. Put the folded No.2 ethibond suture into the guide wire loop, pull out the curved hollow guide and pull the blind end of No.2 ethibond out of the hole in the distal cortex of bone. Put the tendon braiding line into the far blind end coil of No.2 ethibond, pull the two free ends and weave it. The thread is pulled into the medullary cavity from the lower foramen and out of the upper foramen. The long head tendon is pulled into the medullary cavity from the distal foramen. After slightly pulling out the proximal foramen (Fig. 1C) , the loop of the mini-steel plate with loop is cut off. Then the two ends of the tendon knitting thread are respectively passed through the central two holes of the mini-steel plate, bending the elbow of 90 degrees and pronating the forearm back. The corresponding sutures are knotted slightly on the mini-steel plate. When elbow joint is flexed and extended, the mini-plate is suspended on the surface of proximal bone hole to complete the suspension and fixation of LHB. After washing the incision, stop bleeding and suture the incision layer by layer. Antibiotics were routinely administered half an hour before operation and 24 hours after operation.III. Rehabilitation.The upper limb is suspended at 90 degrees for 6 weeks. Passive motion training can be started the next day after operation. Active elbow flexion is prohibited within 6 weeks and elbow flexion weight training is prohibited within 12 weeks.IV. Observation indicators and evaluation of therapeutic effect.After 3 months and 12 months of follow-up, radiographs of shoulder joint were performed to observe whether there were plate displacement, osteolysis under plate and pop-eye signs. VAS score, flexor strength and supinator strength of elbow joint, UCLA shoulder score and ASES score were used to evaluate the effect of operation at 1 year follow-up.V. Statistical methods.Using SPSS19 software, the mean was expressed by ±s. The difference between the two groups was analyzed by t test, and P <0.05 was considered to have statistical significance.

There were no complications in 9 patients during and after operation. All patients were followed up for 1 year. There was no plate loosening, plate osteolysis and pop-eye sign found. One year after operation, all patients had grade V supination and elbow flexion strength. Shoulder pain was significantly relieved. The excellent and good rates of UCLA shoulder score and ASES score were 100%. VAS, UCLA shoulder score and ASES score had significant differences.

Modified keyhole fixation for the treatment of LHB rupture has the advantages of low operation difficulty, high safety and reliable fixation, which is worthy of clinical promotion.