The monostotic fibrous dysplasia with extensive lesions in the humerus: A report of two cases and review of the literature

Yu Guo; Dehong Feng; Ling Wang; Yujian Ding; Yi Liu; Junshan He; Jijun Zhao; Xiaofeng Gu

doi:10.4103/digm.digm_34_22

CASE REPORT

Year : 2023 | Volume : 9 | Issue : 1 | Page : 5

The monostotic fibrous dysplasia with extensive lesions in the humerus: A report of two cases and review of the literature

Yu Guo, Dehong Feng, Ling Wang, Yujian Ding, Yi Liu, Junshan He, Jijun Zhao, Xiaofeng Gu
Department of Orthopedic, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu, China

Date of Submission	30-Jul-2022
Date of Decision	13-Nov-2022
Date of Acceptance	04-Jan-2023
Date of Web Publication	06-Mar-2023

Correspondence Address:
Dehong Feng
The Affiliated Wuxi People's Hospital of Nanjing Medical University, No. 299, Qingyang Road, Liangxi, Wuxi, Jiangsu
China

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/digm.digm_34_22

Abstract

Fibrous dysplasia (FD) is a common benign skeletal disease. In this report, we retrospectively analyzed two cases of monostotic FD with extensive lesions involving the middle and proximal humerus with fractures, where a thorough curettage and autograft followed by interfixation were performed. However, one patient was cured successfully, and the other one had repeated recurrences and pathological fractures. Finally, with the help of computer-aided design and three-dimensional printing technology, the other one patient was cured by unconstrained reverse shoulder arthroplasty combined with allograft-prosthetic composite technology.

Keywords: Allograft-prosthetic composite, Fibrous dysplasia, Reverse shoulder arthroplasty

How to cite this article:
Guo Y, Feng D, Wang L, Ding Y, Liu Y, He J, Zhao J, Gu X. The monostotic fibrous dysplasia with extensive lesions in the humerus: A report of two cases and review of the literature. Digit Med 2023;9:5

How to cite this URL:
Guo Y, Feng D, Wang L, Ding Y, Liu Y, He J, Zhao J, Gu X. The monostotic fibrous dysplasia with extensive lesions in the humerus: A report of two cases and review of the literature. Digit Med [serial online] 2023 [cited 2023 Jun 8];9:5. Available from: http://www.digitmedicine.com/text.asp?2023/9/1/5/371253

Introduction

Fibrous dysplasia (FD) is a common benign disorder of the bone, characterized by the extensive proliferation of fibrous tissue within the bone marrow leading to osteolytic lesions and pathologic fractures.^[1],[2],[3] It can occur in single bone (monostotic form) or multiple bones (polyostotic form).^[4],[5] The common sites of skeletal involvement of monostotic FD are the long bones, ribs, craniofacial bones, and axial bones.^[6] As far as we know, only several scholars have thematically reviewed studies concerning FD in the humerus, covering a limited number of patients with rare cases.^{[7],[8],[9],[10]} In line, only single-digit cases of FD in the humerus have been reported in the literature.^{[11],[[12],[13],[14],[15],[16]} Of the 55 cases with monostotic FD in the Henry's group, only four were humeral lesions.^[17]

In the current report, we retrospectively analyzed two cases of monostotic FD with extensive lesions involving the middle and proximal humerus complicated with fractures, where a thorough curettage and autograft followed by interfixation were performed. However, the two patients experienced different therapy processes. One patient was cured successfully, and the other one suffered repeated recurrences and pathological fractures. Eventually, with the assistance of computer-aided design (CAD) and three-dimensional printing (3DP) technology, an unconstrained reverse shoulder arthroplasty (RSA) combined with allograft-prosthetic composite (APC) technology was used for humeral reconstruction in this patient.

Case Reports

Patient 1

A 30-year-old female was evaluated for acute pain in the right upper arm following a trauma in May 2015. Some swelling was present over the affected arm area. The range of active motion of the right shoulder was limited to 30° in abduction and forward elevation. X-rays and computed tomography (CT) images revealed an 18.0 cm × 4.5 cm sized polycystic lesion, including an 11.0 cm × 4.5 cm sized separate cystic lesion in the right proximal-middle humerus, combined with a pathologic fracture in the middle humerus [Figure 1]a. Magnetic resonance imaging (MRI) data revealed that the proximal humeral cancellous bone changed into lobulus images on T2WI. The histological diagnosis obtained through an open biopsy was FD.

Figure 1: Image information of patient 1. (a) X-rays showing a polycystic lesion including a separate cystic lesion in the right proximal-middle humerus, combined with a pathologic fracture in the middle humerus. (b) Postoperative radiograph showing the grafting of free right fibula autograft and cancellous allografts with interfixation. (c) No local recurrence was noted up to 4 years after surgery. The fibula graft remains clearly visible throughout the consolidation process.

Click here to view

Due to the enlargement of the tumor size and the pathologic fracture, a thorough curettage followed by the grafting of the free right fibula autograft and cancellous allografts (Shanxi Aorui Biomaterials Co., Ltd., Xian, Shanxi, China) was performed. A titanium alloy plate (Suzhou Kangli Orthopaedics Instrument Co., Ltd., Suzhou, Jiangsu, China) was utilized to preserve the integrity of the affected humerus [Figure 1]b.

The range of motion exercises was initiated 2 days after the surgery, and the interfixator was removed 29 months later. No local recurrence was detected up to 4 years after the surgery [Figure 1]c. The range of active motion of the right shoulder was 135° in abduction and 125° in forward flexion. The Constant–Murley score was 94%. The Musculoskeletal Tumor Society (MSTS) score was 29 (96.7%).

Patient 2

A 45-year-old female was first hospitalized with severe pain of the left upper arm after a trauma in December 2015. X-rays and CT images demonstrated an extensive lytic lesion in the middle humeral metaphysis with a pathologic fracture [Figure 2]a. MRI data revealed robust bone marrow signal abnormalities. The histologic diagnosis through an open biopsy confirmed the presence of FD. Subsequently, the patient underwent an intralesional curettage and bone grafting followed by the interfixation [Figure 2]b. The bone grafts consisted of a free left fibula autograft and iliac autografts. However, only 7 months postoperatively, the patient experienced the second episode of a pathologic fracture in the distal humerus [Figure 2]c. A longer plate interfixation following the second intralesional curettage and bone grafting (cancellous allografts, Beijing Xinkangchen Medical Technology Development Co., Ltd., Beijing, China) was carried out subsequently [Figure 2]d. The alloy plates used in both patients 1 and 2 were manufactured by the same company.

Figure 2: Image information of patient 2. (a) Preoperative radiograph demonstrated an extensive polycystic lesion of the left humerus with a pathologic fracture involving the middle humerus. (b) X-rays after the surgery of intralesional curettage and bone grafting followed with the interfixation. (c) The second episode of pathologic fracture in the distal humerus (the fibula autograft was found to gradually turn into dysplastic tissue postoperatively). (d) A longer plate interfixation following the second intralesional curettage and bone grafting. (e) X-rays and the resinous model printed with 3DP according to the reverse data of thin-slice CT: The humeral head was severely damaged, with a severe pathological fracture in the surgical neck. (f) The implants and surgical scheme were designed with CAD. (g) The affected humerus after curettage (left) and the reconstruction of the rotator cuff insertions in the proximal end of the allogeneic humerus (right). (h) X-rays demonstrated satisfactory prosthesis position without allograft resorption. CT: Computed tomography, CAD: Computer-aided design, 3DP: Three-dimensional printing.

Click here to view

Unfortunately, the patient was admitted again because of the third episode of a pathologic fracture in the left humerus 30 months after the second surgery. Radiographs showed an expansive polycystic lesion presented as typical "ground-glass" appearance, extending to the whole humerus with a pathologic fracture in the humeral surgical neck, which is seen to disrupt the cortex [Figure 2]e. The lytic lesion was enlarged and extended proximally to the humeral head surrounded by a thin bone shell, indicating an extensive bone defect of the humeral head.

In view of the repeated recurrences and the difficulty in restoring the osseous integrity of the humerus, a surgical scheme of an unconstrained RSA combined with an APC reconstruction after the removal of lesions was determined.

Then, 3D images of the affected shoulder and humerus were digitally reconstructed based on the reverse data of thin-slice CT, and engineers and surgeons used CAD software to create a surgical proposal [Figure 2]f. The proposal included the extent of bone removal, the implant size and position, the screw trajectory and size, and the allograft length. The allograft length was calculated as the contralateral humeral length minus the remaining normal bone length on the operative side. An implant composed of a glenoid prosthesis and a long-stem humeral prosthesis was customized by Beijing Chunlizhengda Medical Instruments Co., Ltd. The glenoid baseplate (with a 3DP porous, 0.3 cm thick surface) was printed using an Arcam Q10 3D printer (Arcam AB, Mölndal, Sweden) with Ti6Al4V medical grade powder (AP and C Advanced Powder and Coatings Inc., Boisbriand, Quebec, Canada), and the pore size and porosity of 3DP porous on the surface were set to 600 μm and 70%, respectively. The glenoid sphere was fabricated with a CoCrMo alloy (Carpenter Technology Corp., Berks County, Pennsylvania, USA). The humeral stem was fabricated with a Ti6Al4V alloy (Baoji Titanium Industry Co., Ltd., Baoji, Shanxi, China). Surgery was performed in accordance with the preoperative CAD-based proposal. A deltopectoral approach was used with an incision of 23.0 cm. The damaged humeral head was removed, and the humeral shaft lesion was thoroughly curetted. Reconstruction of the humerus was performed after the glenoid component had been implanted. The humeral prosthesis was cemented into the allograft, and then, the component was implanted into the defect of the native humerus. The allogeneic humerus (Beijing Xinkangchen Medical Technology Development Co., Ltd., Beijing, China) and the host bone were fixed together by a plate. The liner was installed, and the shoulder joint was reduced. The rotator cuff insertions were sewn to the drilled holes in the proximal end of the allogeneic humerus [Figure 2]g.

Postoperatively, the shoulder joint was immobilized in the position of abduction 60° for 1 week, and then, the range of motion exercises was started. Up to 15 months after the surgery, no tumor recurrence, infection, and prosthesis dislocation or loosening was observed. The patient had no major complaints of shoulder pain. X-rays demonstrated satisfactory prosthesis position without allograft resorption [Figure 2]h. The range of active motion of the right shoulder was 100° in abduction and 110° in forward flexion. The Constant–Murley score was 80%. The MSTS score was 26 (86.7%).

Discussion

According to the 4^th edition of the "WHO Classification of Tumours of Soft Tissue and Bone," FD is classified as a "tumor of undefined neoplastic nature," and it represents approximately 5%–7% of benign bone tumors.^[18] A few authors have stated that the best approach to FD management is a nonsurgical procedure^[9],[19] or a minimally invasive surgical procedure,^[15] but the surgical intervention consisting of intralesional curettage (or extralesional resection) and bone grafting with or without interfixation is still a preferable treatment choice for correction of deformity, prevention of pathologic fracture, and/or eradication of symptomatic lesions.^{[20],[21],[22],[23],[24],[25]} In our two patients, the intralesional curettage with bone grafting and interfixation were chosen, although the FD lesions were very extensive.

Some reports have documented the recurrence after intralesional curettage with or without bone grafting.^[14],[22] In our study, no evidence of local recurrence was observed 4 years after the surgery in patient 1. However, in patient 2, the free left fibula autograft and iliac autografts were found to gradually turn into a dysplastic tissue after being incorporated into the host bone postoperatively, indicating recurrence of the tumor. It might have been related to the incomplete curettage.

More successful outcomes of FD treatments in patients who underwent an en bloc resection and bone graft reconstruction have been reported.^[20],[24] Nevertheless, these reports do not include cases of FD, in which the humeral head was resected and the shoulder replacement was performed after lesion resection. Shoulder prosthesis is suitable for limb salvage after resection of proximal humeral tumors, but its application is more common in cases of malignant tumors and rare in benign tumors.^[26–32] In Wilde's^[27] cohort of 14 patients, only three patients developed benign bone tumors (two recurrent giant cell tumors and one eosinophilic granuloma) and underwent shoulder replacement, and among the 10 patients in Kaa's^[30] group, only one patient with a benign tumor (an aneurysmatic bone cyst) accepted shoulder arthroplasty.

In view of the above situation, several various surgical schemes were carefully reviewed and selected during the last hospitalization of patient 2. It is quite challenging to rebuild the integrity of the humerus, given the humerus split into a shaft with damaged cortex and a head only with a hollow shell. Furthermore, after a thorough intralesional curettage of the humeral head, it is impossible to preserve the humeral head itself. Considering severe damages noted in the entire humerus, especially the humerus head, the internal fixation was not expected to achieve sufficient strength and was therefore dismissed. Eventually, a reconstructive scheme for the shoulder joint following the resection of humeral head and the third curettage of humeral shaft lesions was determined.

Ideally, reconstruction of the shoulder joint must provide both motion and stability.^[33] Historically, the shoulder reconstruction involving a hemiarthroplasty provided patients with an "acceptable" outcome in terms of hand positioning and hand function, but subluxation or dislocation of the glenohumeral joint and lack of shoulder function were common.^[34] Unlike traditional hemiarthroplasty, the reverse prosthesis is inherently stable to superior migration and subluxation, showing improved function and lower incidence of complications.^[35],[36] This is mainly attributable to its semi-constrained design, which improves the joint stability in the absence of soft-tissue stabilizers, while also allowing the deltoid muscle to provide sufficient strength for elevation without a functional rotator cuff.^[37–39] As such, reconstruction employing a reverse prosthesis had become our preferred technique in patient 2 following the resection of the proximal humerus.

APC technology represents an attractive option for large bone defects of the proximal humerus at the time of reconstructive shoulder surgery.^[40],[41] More recently, some scholars have suggested using an unconstrained RSA combined with an allograft as a reconstructive method.^{[30],[31],[35]} The main advantages of using APC technology with a RSA are that this approach allows the restoration of bone stock, thus improving the fixation and stability of the prosthesis, and provides the possibility to perform soft-tissue reconstruction to improve shoulder motion. By reattaching the shoulder tendons to the allograft, one could expect to restore both active forward elevation and external rotation.^[42] Thus, the unconstrained RSA combined with APC technology was first applied in patient 2. During the initial follow-up, the patient achieved satisfactory shoulder function, presenting a positive short-term outcome.

CAD of individualized prosthesis and implantation schemes makes the surgical operation more predictable and effective, thus facilitating the surgical procedure.^[43],[44] The use of CAD technology can also guide the accurate installation of the glenoid sphere and the effective adjustment of the humeral length during the operation, thus avoiding scapular notching and joint dislocation. Meanwhile, the customized 3D-printed prosthesis based on the anatomical structure of the patient's skeleton can achieve the best matching between the prosthesis and the patient, which is highly beneficial for initial stability.^[45–47] It has been reported that the pore size and porosity of 3D-printed scaffolds were most conducive to bone ingrowth in the range of 600 μm–700 μm and 50%–75%.^[48-50] In accordance with the literature, the pore size and porosity of the 3D-printed glenoid baseplate of patient 2 were set to 600 μm and 70%, which ensures the medium- and long-term biological integration of the prosthesis and the host bone.

Conclusions

The current report demonstrates the usefulness of an unconstrained RSA prosthesis combined with the APC technology. This approach greatly facilitated the biological reconstruction of the stable and functional shoulder of the proximal humerus damaged with extensive bone defects and multiple pathological fractures in FD patients. However, the surgical scheme of retaining the original bone and joint structure should remain the first choice. The main limitation of this study is that it included only two cases. Although the final results were satisfactory, more cases and longer follow-up periods are warranted to further validate our findings.

Ethics approval and consent to participate

This retrospective study was approved by the Ethics Committee of The Affiliated Wuxi People's Hospital of Nanjing Medical University. Informed written consent requirement was waived.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This study received financial support through the Social Development Science and Technology Demonstration Programme (N20192006), funded by Wuxi Municipal Bureau on Science and Technology.

Conflicts of interest

There are no conflicts of interest.

References

1.	DiCaprio MR, Enneking WF. Fibrous dysplasia. Pathophysiology, evaluation, and treatment. J Bone Joint Surg Am 2005;87:1848-64.
2.	Boileau P, Raynier JL, Chelli M, Gonzalez JF, Galvin JW. Reverse shoulder-allograft prosthesis composite, with or without tendon transfer, for the treatment of severe proximal humeral bone loss. J Shoulder Elbow Surg 2020;29:e401-15.
3.	Burke AB, Collins MT, Boyce AM. Fibrous dysplasia of bone: Craniofacial and dental implications. Oral Dis 2017;23:697-708.
4.	Florez H, Peris P, Guañabens N. Fibrous dysplasia. Clinical review and therapeutic management. Med Clin (Barc) 2016;147:547-53.
5.	Chapurlat R, Legrand MA. Bisphosphonates for the treatment of fibrous dysplasia of bone. Bone 2021;143:115784.
6.	Rotman M, Hamdy NA, Appelman-Dijkstra NM. Clinical and translational pharmacological aspects of the management of fibrous dysplasia of bone. Br J Clin Pharmacol 2019;85:1169-79.
7.	Burns AH, Wilcox Iii RB. Cystic fibrous dysplasia of the humerus. J Orthop Sports Phys Ther 2011;41:459.
8.	Matsuya S, Hatori M, Hosaka M, Ito K, Dohi O, Endo M, et al. Operative treatment by external fixation for polyostotic fibrous dysplasia in the elbow joint. A case report. Ups J Med Sci 2006;111:269-74.
9.	Mrabet D, Rekik S, Sahli H, Ben Amor M, Meddeb N, Sellami S. An extensive hemimelic polyostotic fibrous dysplasia: A case report. Rheumatol Int 2012;32:1075-8.
10.	Nishio J, Kuwabara Y, Nabeshima S, Iwasaki H, Naito M. PET-positive polyostotic fibrous dysplasia mimicking Ollier disease. In Vivo 2013;27:821-6.
11.	Grzegorzewski A, Pogonowicz E, Sibinski M, Marciniak M, Synder M. Treatment of benign lesions of humerus with resection and non-vascularised, autologous fibular graft. Int Orthop 2010;34:1267-72.
12.	Ippolito E, Bray EW, Corsi A, De Maio F, Exner UG, Robey PG, et al. Natural history and treatment of fibrous dysplasia of bone: A multicenter clinicopathologic study promoted by the European Pediatric Orthopaedic Society. J Pediatr Orthop B 2003;12:155-77.
13.	Kumta SM, Leung PC, Griffith JF, Kew J, Chow LT. Vascularised bone grafting for fibrous dysplasia of the upper limb. J Bone Joint Surg Br 2000;82:409-12.
14.	Moretti VM, Slotcavage RL, Crawford EA, Lackman RD, Ogilvie CM. Curettage and graft alleviates athletic-limiting pain in benign lytic bone lesions. Clin Orthop Relat Res 2011;469:283-8.
15.	Rosario MS, Hayashi K, Yamamoto N, Takeuchi A, Miwa S, Taniguchi Y, et al. Functional and radiological outcomes of a minimally invasive surgical approach to monostotic fibrous dysplasia. World J Surg Oncol 2017;15:1.
16.	Shidham VB, Chavan A, Rao RN, Komorowski RA, Asma Z. Fatty metamorphosis and other patterns in fibrous dysplasia. BMC Musculoskelet Disord 2003;4:20.
17.	Henry A. Monostotic fibrous dysplasia. J Bone Joint Surg Br 1969;51:300-6.
18.	Coindre JM. New WHO classification of tumours of soft tissue and bone. Ann Pathol 2012;32:S115-6.
19.	Leet AI, Collins MT. Current approach to fibrous dysplasia of bone and McCune-Albright syndrome. J Child Orthop 2007;1:3-17.
20.	Gebert C, Hillmann A, Schwappach A, Hoffmann CH, Hardes J, Kleinheinz J, et al. Free vascularized fibular grafting for reconstruction after tumor resection in the upper extremity. J Surg Oncol 2006;94:114-27.
21.	Koskinen EV. Wide resection of primary tumors of bone and replacement with massive bone grafts: An improved technique for transplanting allogeneic bone grafts. Clin Orthop Relat Res 1978;134:302-19.
22.	Lindner N, Brinkschmidt C, Suddendorf A, Rödl R, Gosheger G, Winkelmann W. Surgical reconstruction of fibrous dysplasia of bone in long-term follow-up. Z Orthop Ihre Grenzgeb 2000;138:152-8.
23.	MacDonald-Jankowski D. Fibrous dysplasia: A systematic review. Dentomaxillofac Radiol 2009;38:196-215.
24.	Traibi A, El Oueriachi F, El Hammoumi M, Al Bouzidi A, Kabiri EH. Monostotic fibrous dysplasia of the ribs. Interact Cardiovasc Thorac Surg 2012;14:41-3.
25.	Verma RR, Paul A. Fibrous dysplasia of the fourth metacarpal: En-bloc resection and free metatarsal transfer. Orthopedics 2006;29:371-2.
26.	Bonnevialle N, Mansat P, Lebon J, Laffosse JM, Bonnevialle P. Reverse shoulder arthroplasty for malignant tumors of proximal humerus. J Shoulder Elbow Surg 2015;24:36-44.
27.	De Wilde L, Boileau P, Van der Bracht H. Does reverse shoulder arthroplasty for tumors of the proximal humerus reduce impairment? Clin Orthop Relat Res 2011;469:2489-95.
28.	Griffiths D, Gikas PD, Jowett C, Bayliss L, Aston W, Skinner J, et al. Proximal humeral replacement using a fixed-fulcrum endoprosthesis. J Bone Joint Surg Br 2011;93:399-403.
29.	Guven MF, Aslan L, Botanlioglu H, Kaynak G, Kesmezacar H, Babacan M. Functional outcome of reverse shoulder tumor prosthesis in the treatment of proximal humerus tumors. J Shoulder Elbow Surg 2016;25:e1-6.
30.	Kaa AK, Jørgensen PH, Søjbjerg JO, Johannsen HV. Reverse shoulder replacement after resection of the proximal humerus for bone tumours. Bone Joint J 2013;95-B: 1551-5.
31.	King JJ, Nystrom LM, Reimer NB, Gibbs CP Jr., Scarborough MT, Wright TW. Allograft-prosthetic composite reverse total shoulder arthroplasty for reconstruction of proximal humerus tumor resections. J Shoulder Elbow Surg 2016;25:45-54.
32.	Maclean S, Malik SS, Evans S, Gregory J, Jeys L. Reverse shoulder endoprosthesis for pathologic lesions of the proximal humerus: A minimum 3-year follow-up. J Shoulder Elbow Surg 2017;26:1990-4.
33.	Guder W, Nottrott M, Streitbürger A, Röder J, Podleska LE, Scheidt P, et al. Complication management following resection and reconstruction of the upper limbs and shoulder girdle. Orthopade 2020;49:104-13.
34.	Houdek MT, Bukowski BR, Athey AG, Elhassan BT, Barlow JD, Morrey ME, et al. Comparison of reconstructive techniques following oncologic intraarticular resection of proximal humerus. J Surg Oncol 2021;123:133-40.
35.	Sanchez-Sotelo J, Wagner ER, Sim FH, Houdek MT. Allograft-prosthetic composite reconstruction for massive proximal humeral bone loss in reverse shoulder arthroplasty. J Bone Joint Surg Am 2017;99:2069-76.
36.	Rugg CM, Coughlan MJ, Lansdown DA. Reverse total shoulder arthroplasty: Biomechanics and indications. Curr Rev Musculoskelet Med 2019;12:542-53.
37.	Burden EG, Batten TJ, Smith CD, Evans JP. Reverse total shoulder arthroplasty. Bone Joint J 2021;103-B: 813-21.
38.	Kozak T, Bauer S, Walch G, Al-Karawi S, Blakeney W. An update on reverse total shoulder arthroplasty: Current indications, new designs, same old problems. EFORT Open Rev 2021;6:189-201.
39.	Ferlauto HR, Wickman JR, Lazarides AL, Hendren S, Visgauss JD, Brigman BE, et al. Reverse total shoulder arthroplasty for oncologic reconstruction of the proximal humerus: A systematic review. J Shoulder Elbow Surg 2021;30:e647-58.
40.	Han J, Kim WL, Kim Y, Cho HS, Oh JH. Does reverse total shoulder arthroplasty with allograft-prosthesis composite (APC) have surgical benefits over hemiarthroplasty with APC in patients with tumors of the proximal humerus? Jpn J Clin Oncol 2022;52:1408-15.
41.	Cox JL, McLendon PB, Christmas KN, Simon P, Mighell MA, Frankle MA. Clinical outcomes following reverse shoulder arthroplasty-allograft composite for revision of failed arthroplasty associated with proximal humeral bone deficiency: 2-to 15-year follow-up. J Shoulder Elbow Surg 2019;28:900-7.
42.	Power I, Throckmorton TW. Treating humeral bone loss in shoulder arthroplasty: Modular humeral components or allografts. Am J Orthop (Belle Mead NJ) 2018;47:29494716.
43.	Hegele J, Seitz L, Claussen C, Baumert U, Sabbagh H, Wichelhaus A. Clinical effects with customized brackets and CAD/CAM technology: A prospective controlled study. Prog Orthod 2021;22:40.
44.	Ciobanu O. The use of CAD/CAM and rapid fabrication technologies in prosthesis and orthotics manufacturing. Rev Med Chir Soc Med Nat Iasi 2012;116:642-8.
45.	Feng D, He J, Zhang C, Wang L, Gu X, Guo Y. 3D-printed prosthesis replacement for limb salvage after radical resection of an ameloblastoma in the tibia with 1 year of follow up: A case report. Yonsei Med J 2019;60:882-6.
46.	Zou Y, Yang Y, Han Q, Yang K, Zhang K, Wang J, et al. Novel exploration of customized 3D printed shoulder prosthesis in revision of total shoulder arthroplasty: A case report. Medicine (Baltimore) 2018;97:e13282.
47.	Bruns N, Krettek C. 3D-printing in trauma surgery: Planning, printing and processing. Unfallchirurg 2019;122:270-7.
48.	Markhoff J, Wieding J, Weissmann V, Pasold J, Jonitz-Heincke A, Bader R. Influence of different three-dimensional open porous titanium scaffold designs on human osteoblasts behavior in static and dynamic cell investigations. Materials (Basel) 2015;8:5490-507.
49.	Ran Q, Yang W, Hu Y, Shen X, Yu Y, Xiang Y, et al. Osteogenesis of 3D printed porous Ti6Al4V implants with different pore sizes. J Mech Behav Biomed Mater 2018;84:1-11.
50.	Bahraminasab M. Challenges on optimization of 3D-printed bone scaffolds. Biomed Eng Online 2020;19:69.