Most fresh Mons fractures can be repositioned by manipulation, and only a few require surgery. However, the treatment of old Monsignor fractures is difficult, and the treatment of radial head repositioning and annular ligament is inconsistent. from 2004 to 2011, 11 cases of old Monsignor fractures in children were treated surgically by ulnar osteotomy lengthening method in our hospital, and satisfactory treatment results were achieved. The analysis is reported as follows. Data and methods I. Clinical data Among the 11 children, 9 were male and 2 were female, 2 were left-sided and 9 were right-sided, aged from 4 to 13 years old, with an average of 7 years old. 11 children were all initially missed cases. The average time from injury to surgery was 5.9 months. All of the children in this group had radial head dislocation after fracture healing. All of them underwent radial head dislocation with internal fixation of ulnar osteotomy and extension plate, without reconstruction of annular ligament, and only joint capsule repair and tightening. The modified Boyd incision (Figure 1) was used to open the humeral radial joint and the proximal ulna layer by layer, paying attention to the protection of the radial nerve and the dorsal interosseous nerve. The brachioradial joint capsule was opened and the scarred fatty tissue was removed from the joint. The joint capsule is trimmed and tightened after resetting. The ulna is osteotomized transversely, and the ulnar osteotomy is usually performed as close to the proximal ulna as possible, but the proximal length of the osteotomy needs to be secured by 2 screws, and the proximal ulnar epiphysis must not be damaged. The length of lengthening is determined by pulling the osteotomy until the radial head is repositioned and temporarily fixing the humeral-radial joint with a Clinique pin; the direction of the wedge opening into the angle after the ulnar osteotomy is determined according to the direction of radial head dislocation. The degree of ulnar angulation was determined by flexing and rotating the forearm and observing the stability of the radial head repositioning. If the radial head is dislocated laterally, then the ulnar osteotomy opens medially, whereas if the radial head is dislocated forward, then the ulnar osteotomy opens posteriorly. The length and angle of the wedge-shaped bone graft were decided according to the degree of lengthening and angulation, and the allograft bone was used in this group of cases; then, the osteotomy and bone graft were fixed with pre-bent reconstruction plates according to the degree of angulation to keep the ulnar bone lengthening and angulation healing. Postoperative treatment After the operation, the elbow joint was flexed 90 degrees, and the forearm was rotated posteriorly with external fixation of the cast for 4 weeks, and functional exercise of the elbow joint was performed after the cast was removed. After healing of the osteotomy, the internal fixation was removed surgically, usually about six months after surgery. Results All cases were followed up. Postoperative follow-up ranged from 1 to 5 years (mean 22 months). According to Mackay[1] et al, the functional assessment was graded into three levels: excellent: no elbow pain, less than 20 degrees of elbow extension and flexion and forearm rotation, normal elbow muscle strength and grip strength. Good: mild elbow and wrist pain, elbow extension and flexion and forearm rotation anterior and posterior obstruction less than 30 degrees, and reduced elbow muscle strength and grip strength. Poor: severe elbow and wrist pain, elbow extension and flexion and forearm rotation anterior and posterior obstruction greater than 30 degrees, and significantly weakened elbow muscle strength and grip strength. According to the above criteria, there were 10 cases of excellent and 1 case of good in this group. There was no subluxation or dislocation on X-ray (Table 1). Postoperative elbow flexion and extension rotation activities were significantly improved, and pain was reduced. (Figure 2) Discussion The treatment of old Manganese fractures with a disease duration greater than 1 month is faced with many problems, with varying opinions and multiple treatment methods reported in the literature. These include surgical removal of the radial head in adulthood (palliative surgery), various reconstructive procedures (including annular ligament reconstruction, radial shortening, ulnar osteotomy, external fixation brace orthopedic and gristle pin fixation of the brachioradialis joint, etc.), which remain controversial. What kind of osteotomy method should be used and whether the annular ligament needs to be reconstructed, the material and method of reconstruction are the main difficulties and controversies at present. I. Characteristics and relationship of fracture dislocation From the anatomical point of view, the radius rotates around the ulna during forearm rotation, and the ulna is the axis. Therefore, angular healing of radial wedge osteotomy will affect forearm rotation, while ulnar wedge osteotomy will not lead to forearm rotation impairment; all x-rays of old Monsignor fractures show that although the radial head is dislocated, there is no angular deformity, while angular deformity healing of ulnar fracture causes radial head dislocation, and the direction of dislocation is consistent with the direction of ulnar angularity. For example, if the ulna is angulated forward, the radial head is dislocated forward; if the ulna is angulated to the radial side, the radial head is dislocated to the radial side. Therefore, if the radial head needs to be repositioned and stabilized by osteotomy, the osteotomy site should be placed at the proximal end of the ulna; the radial head grows faster after dislocation and has overgrowth compared with the ulna. As a result, it causes limitation of elbow joint movement, elbow valgus and instability, limited forearm rotation, elbow joint pain and interosseous dorsal nerve palsy, etc. The overgrown radial head is lengthened compared with the ulna, which affects the repositioning of the radial head during surgery, so it is necessary to balance the length of the ulnar and radial bones in two ways: one is to shorten and osteotomize the overgrown radius, and the other is to lengthen the ulna accordingly. Since the time of surgery in this group of children was within 2 years from the onset of the disease, the radial head overgrowth was not much, and the radial head could be reset by lengthening the ulna during surgery; however, radial shortening is really our alternative, if lengthening the ulna is not enough to reset the radial head, radial shortening osteotomy is needed. Second, the importance of ulnar osteotomy and extended angular fixation For the osteotomy method of old Monsignor fracture, some choose radial shortening osteotomy and some choose ulnar osteotomy, which is more reported in the literature [2], and most scholars advocate that the ulna needs to be osteotomized and extended angular fixation, and only through ulnar osteotomy can we obtain stable repositioning of the radial head and restore the anatomic force line of the radial head. Our experience is that only after open wedge osteotomy through the ulna can we obtain the repositioning of the humeral radial joint and the stability after repositioning to prevent postoperative re-dislocation, which is a key step in the surgical treatment of old Monsignor fractures, and we can generally move the elbow joint and forearm directly after intraoperative repositioning to check its stability. III. Rationale of surgical design According to the above-mentioned view, we designed the surgical approach: a modified Boyd incision was made so that the incision was slightly panned posteriorly, which could fully expose the brachioradialis joint and also fully reveal the proximal and middle ulnar segments and, if necessary, the proximal radius, and the surgery was completed through this incision in all cases in this group. The humeral-radial joint is exposed, intra-articular scars, ligaments and other soft tissues are removed to clear the obstacle for radial head repositioning [3]; the ulna is wedge-shaped osteotomized and lengthened to provide space for radial head repositioning [4]; the proximal ulna is wedge-shaped open (according to the direction of radial head dislocation) and lengthened, the wedge-shaped allograft bone is filled to support the osteotomy, the reconstruction plate is pre-bent and fixed, while the pre-bent reconstruction plate acts as a mold to hold the open and lengthened ulna and The bone graft is fixed together so that the osteotomy orthosis heals according to the pre-bending angle of the reconstruction plate and prevents the osteotomy from retracting; the humeral radial joint capsule is tightened to prevent the radial head from dislocating again. IV. Whether the annular ligament needs to be reconstructed The reconstruction or not of the annular ligament is one of the most controversial parts of the treatment of old Monsignor fractures. Most early scholars believed that repair and reconstruction of the annular ligament should be emphasized [5,6]. A reconstructed annular ligament can limit the re-dislocation of the radial head and give it better stability. There are several methods to reconstruct the annular ligament, such as using triceps tendon membrane, forearm fascia [7], and palmaris longus tendon [8], but all of these procedures are complicated, and the reconstructed annular ligament has no blood flow, poor growth ability, and cannot grow with the development of the radial neck consequently, forming a fascia to limit the development of the radial neck, which in turn limits the rotational function of the forearm. Moreover, the reconstructed ligament has different degrees of attenuation and laxity [9,10], leading to the occurrence of radial head re-dislocation. We advocate that intraoperative reconstruction of the annular ligament is not necessary because the annular ligament in old Mons fractures is scarred and anatomically indistinguishable from satisfactory in situ reconstruction. Instead, the intraoperative joint capsule can be reshaped after excision of the scar and tightening and reshaping of the excess capsule wall after freeing, and it can prevent secondary displacement of the radial head in concert with the interosseous membrane. Intraoperative careful cleaning of the scar and fatty tissue within the joint that hinders repositioning is required, which is consistent with the view of Ji Shijun et al [11]. Summarizing the existing treatment experience, we believe that old Mons fractures should be treated surgically as early as possible. We used this method of treatment to achieve satisfactory therapeutic results, which is worthy of further research and clinical promotion. V. Strengthening awareness and preventing missed diagnosis Generally, fresh Manganese fractures can be cured by conservative treatment such as manual repositioning, and surgical intervention is rarely required. However, due to insufficient clinical experience or atypical cases, missed diagnosis may result in old Monsignor fractures, which may complicate and make the treatment difficult and increase the pain of the child and the economic burden of the family. Happily, with the popularization of knowledge about this particular fracture, most orthopedic surgeons are able to recognize Manganese fractures, especially at the early stage of fracture, so that the incidence of old Manganese fractures has decreased year by year in recent years, and there are only 11 surgical cases in our hospital in the past 7 years. Therefore, in our clinical work, we need to strengthen the awareness and education of Manganese fracture to prevent the occurrence of missed diagnosis.