OBJECTIVE: Reverse shoulder arthroplasty has demonstrated excellent clinical efficacy for patients with shoulder joint diseases and is increasingly in demand. Traditional surgery faces challenges such as limited exposed surfaces and a narrow field of vision, leading to a shorter prosthesis lifespan and a higher risk of complications. In this study, an optical navigation system was proposed to assist surgeons in real-time tracking of the surgical scene.
METHODS: Our optical navigation system was developed using the NDI Polaris Spectra device and several open-source platforms. The first step involved using the preoperative medical image to plan screw implantation paths. Real-time tracking of the patient phantom or cadaver and the surgical instrument was achieved through registration and calibration algorithms. Surgeons were guided on drilling through visualization methods. Postoperative results were compared with the planned implantation paths, and an algorithm was introduced to correct errors caused by the incorrect beginning points.
RESULTS: Experiments involved three scapula cadavers and their corresponding phantoms with identical anatomy. For each experiment, three holes were completed with drills with diameters of 3.2 mm and 8.0 mm, respectively. Comparisons between the postoperative actual screw implantation paths and the preoperative planned implantation paths revealed an entry error of 1.05 ± 0.15 mm and an angle error of 2.47 ± 0.55° for phantom experiments. For cadaver experiments, the entry error was 1.53 ± 0.22 mm, and the angle error was 4.91 ± 0.78°.
CONCLUSIONS: Our proposed optical navigation system successfully achieved real-time tracking of the surgical site, encompassing the patient phantom or cadaver and surgical instrument, thereby aiding surgeons in achieving precise surgical outcomes. Future study will explore the integration of robots to further enhance surgical efficiency and effectiveness.

UNASSIGNED: The aim was to evaluate the effects of different glenosphere eccentricities on impingement, range of motion (ROM), and muscle length during standard activities in reverse total shoulder arthroplasty (RSA).
UNASSIGNED: In this study, we utilized computational modeling techniques to create native shoulder and shoulder models undergoing RSA and simulate shoulder movements in all abduction-adduction, flexion-extension, and rotation. We tested a total of 36 different glenosphere configurations, which included three different inferior tilts (0°, +10°, +20°) and two different lateral offsets (0 mm and +4 mm), as well as six different glenosphere eccentricities (concentricity, inferior, posterior, anterior, anteroinferior, and posteroinferior). We evaluated the maximum impingement-free ROM, impingement sites, and muscle lengths.
UNASSIGNED: All glenosphere configurations exceeded 50% of native shoulder ROM in three planes and total global ROM. In abduction-adduction, there was no significant difference among the different glenosphere eccentricities (p > 0.05). In flexion-extension, the posteroinferior eccentricity had the maximum ROM among the different eccentricities, but no significant difference among the different glenosphere eccentricities (p > 0.05). In rotation, there was a significant difference overall, and anteroinferior eccentricity had a significant advantage over concentricity (p < 0.05). In total global ROM, anteroinferior eccentricity had a significant advantage over concentricity when lateral offset was 0 mm (p < 0.05). In all models of glenosphere eccentricities, only the elongation of the infraspinatus muscle was statistically significant (p < 0.05).
UNASSIGNED: Glenosphere eccentricity significantly influenced rotation, total global ROM, and the length of the subscapularis muscle. Among them, anteroinferior offset achieved the maximum ROM in abduction-adduction, rotation, and total global activities. Both anteroinferior and inferior glenoid eccentricity showed significant advantages over the concentricity in rotation and total global ROM.
UNASSIGNED: Basic Science Study; Computer Modeling.

BACKGROUND: Giant cell tumors of bone (GCTBs) are rare, aggressive tumors, and the proximal humerus is a relatively rare location for GCTBs; limited evidence exists on which surgical approaches and reconstruction techniques are optimal. In the largest case series to date, we evaluated the recurrence rate of proximal humeral GCTBs and the functional outcomes of different resection and reconstruction options in this multicenter study.
METHODS: All 51 patients included in this study received initial surgical treatment for proximal humeral GCTBs from January 2007 to December 2020, with a minimum 2-year follow-up period. Local recurrence and functional outcomes were statistically analyzed in relation to demographic, clinical, and primary surgical variables. Functional outcomes were reported by patients and were assessed by the Musculoskeletal Tumor Society score and QuickDASH instrument (shortened version of the Disabilities of the Arm, Shoulder and Hand instrument).
RESULTS: The mean follow-up period was 81.5 months (range, 30-191 months), and the overall recurrence rate was 17.6% (9 of 51 patients). The majority of recurrences (n = 7) occurred in the first 2 years of follow-up. The intralesional curettage group (n = 23) showed a statistically significant difference in the recurrence rate compared with the en bloc resection group (n = 28) (34.8% vs. 3.6%, P = .007). Among shoulders receiving en bloc resection, 16 were reconstructed with hemiarthroplasty; 8, reverse total shoulder arthroplasty (rTSA) with allograft-prosthetic composite (APC) reconstruction; and 4, arthrodesis. On the basis of intention-to-treat analysis, the mean functional Musculoskeletal Tumor Society scores of the groups undergoing curettage, rTSA with APC, hemiarthroplasty, and arthrodesis were 26.0 ± 3.1, 26.0 ± 1.7, 20.3 ± 2.8, and 22.5 ± 1.3, respectively (P < .001 [with P < .001 for curettage vs. hemiarthroplasty and P = .004 for rTSA with APC vs. hemiarthroplasty]) and the mean QuickDASH scores were 14.0 ± 11.0, 11.6 ± 4.5, 33.1 ± 11.8, and 21.6 ± 4.7, respectively (P < .001 [with P < .001 for curettage vs. hemiarthroplasty and P = .003 for rTSA with APC vs. hemiarthroplasty]).
CONCLUSIONS: On the basis of our data, en bloc resection followed by reverse shoulder arthroplasty showed a lower recurrence rate and no significant difference in functional outcome scores for proximal humeral GCTBs compared with intralesional curettage. Therefore, we believe that rTSA with APC may be reasonable for the initial treatment of proximal humeral GCTBs.

OBJECTIVE: Four principal treatment modalities are applied to treat complex proximal humeral fractures in older adults: conservative treatment, open reduction internal fixation, hemiarthroplasty, and reverse shoulder arthroplasty. However, among these, the optimal treatment modality has yet to be determined. Therefore, a network meta-analysis was carried out to compare treatment modalities and assess their effectiveness.
METHODS: The databases PUBMED, EM-BASE, the Cochrane Central Register of Controlled Trials, Web of Science, and CNKI were searched for randomised controlled trials on complex proximal humeral fractures in older people, ranging from inception of each database to May 2023.
RESULTS: This meta-analysis included 14 randomised controlled trials, containing 791 patients aged over 60 years who were treated for complex proximal humeral fractures. Reverse shoulder arthroplasty and hemiarthroplasty yielded the highest Constant shoulder scores, whilst conservative treatment performed poorly. Hemiarthroplasty and open reduction internal fixation yielded the best performances on the visual analogue pain scale, whilst conservative treatment performed poorly. Reverse shoulder arthroplasty and open reduction internal fixation allowed for maximum forward flexion and outreach of range of motion, whilst hemiarthroplasty allowed for the least. Open reduction internal fixation and reverse shoulder arthroplasty allowed for maximum internal rotation of the range of motion, whilst conservative treatment allowed for the least. Hemiarthroplasty and conservative treatment allowed for maximum external rotation of the range of motion, whilst open reduction internal fixation allowed for the least.
CONCLUSIONS: Compared with open reduction internal fixation, reverse shoulder arthroplasty yields better Constant shoulder scores and allows for greater forward flexion and outreach of range of motion of the shoulder joint in complex proximal humerus fractures in older patients. Meanwhile, hemiarthroplasty yields the best visual analogue scale scores and allows for maximum external rotation of the range of motion. However, open reduction with internal fixation remains the preferred clinical treatment for complex proximal humeral fractures in older patients.

UNASSIGNED: Proximal humeral fractures are the third most common fracture in the body, and their incidence is rising year by year as the population ages. However, the treatment of the proximal humerus in parts 3 and 4 is still debatable, necessitating a network meta-analysis to determine the best treatment for each treatment modality.
UNASSIGNED: We searched PubMed, Embase, Cochrane Library for randomized controlled trials on proximal humeral fractures up to June 21, 2022. We performed data extraction and literature quality assessment by two independent authors and extracted constant score and reoperation rate as indicators for evaluation. Stata software, Revman software, JAGS software and the R-based BlandAltmanLeh package, gemtc package and riags package were used to perform this Bayesian network meta-analysis.
UNASSIGNED: Following screening, 11 papers with a total of 648 participants were included in the analysis. The SUCRA values for the constant score were in the following order: RSA, IMN, Conservative, HA, and LP, and the SUCRA values for the reoperation rate were LP, HA, IMN, Conservative, and RSA.
UNASSIGNED: The elderly with 3- or 4-part proximal humeral fractures should consider RSA because it received the best evaluation ranking in terms of constant score and reoperation rate.
UNASSIGNED: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022341209, identifier: CRD42022341209.

The present meta-analysis was conducted to compare the safety and effectiveness of reverse shoulder arthroplasty (RSA) and hemiarthroplasty (HA) in the treatment of osteoporotic proximal humeral fractures in elderly patients. The Embase, Pubmed Central, Cumulative Index to Nursing and Allied Health Literature, ProQuest Dissertations and Theses, Cochrane Library and Chinese Biomedical databases were searched between January 2009 and January 2022 to identify relevant studies. According to the search strategy, a total of 210 associated studies were retrieved and 16 were finally included. Review Manager 5.4 software was used for the data analysis. This study indicated that patients in the RSA group had significantly improved treatment outcomes compared with patients in the HA group, as assessed by Constant-Murley Shoulder Outcome Score (95% CI, 1.69-3.76; P<0.001), American Shoulder and Elbow Surgeons score (95% CI, 11.81-24.88; P<0.001) and shoulder range of motion (ROM; 95% CI, 3.41-9.07; P<0.001). However, the HA group was superior to the RSA group in terms of the Oxford Shoulder score (95% CI, 2.89-11.11; P<0.001). There was no significant statistical difference between the two groups in terms of the Disabilities of the Arm, Shoulder and Hand score and complications. Overall, for the treatment of osteoporotic proximal humeral fractures in the elderly, the RSA group had improved postoperative ROM and functional scores compared with the HA group, without significant difference in the incidence of complications. However, HA remains a safe and reliable treatment option.

UNASSIGNED: To investigate the effectiveness of three-dimensional (3D) printed total scapula for reverse shoulder arthroplasty in the treatment of scapular tumors.
UNASSIGNED: Between November 2017 and December 2021, 5 patients with scapular tumors were treated by reverse shoulder arthroplasty with 3D printed total scapula. There was 1 male and 4 females. The age ranged from 44 to 59 years, with an average of 50.4 years. There were 2 cases of chondro sarcoma, 1 case of high-grade osteosarcoma, 1 case of lung cancer with scapular metastasis, and 1 case of ligamentoid fibromatosis recurrence. The disease duration was 4-8 months, with an average of 5.8 months. According to the Musculoskeletal Tumor Society (MSTS) scapular girdle classification criteria, 4 cases of tumors involved both S1 and S2 zones, and 1 case involved S2 zone. The tumor diameters ranged from 4.2 to 11.2 cm, with an average of 6.1 cm. The operation time, intraoperative blood loss, and blood transfusion were recorded. During follow-up, the MSTS score was used to evaluate the recovery of limb function of the patients. The sink depth of the affected shoulder, complications, and oncological outcomes were observed. The position of the prosthesis was reviewed by imaging.
UNASSIGNED: The operation time ranged from 155 to 230 minutes, with an average of 189 minutes. The intraoperative blood loss was 100-1 500 mL, with a median of 600 mL. Two patients were received blood transfusion of 800 mL and 1 850 mL respectively during operation. All incisions healed by first intention, and no complications such as infection occurred. All patients were followed up 4-22 months, with an average of 13 months. Two patients died at 8 and 15 months after operation respectively due to multiple metastases and organ failure. At last follow-up, the MSTS score of all patients was 73%-83%, with an average of 77.4%. The affected shoulder was 2-4 cm lower than the contralateral side, with an average of 3 cm. Imaging examinations showed that no prosthesis loosening, dislocation, or fracture occurred during follow-up.
UNASSIGNED: Reverse shoulder arthroplasty with 3D printed total scapula can obtain good shoulder function and appearance. Patients have high acceptance and satisfaction with this surgical method.
UNASSIGNED: 探讨3D打印全肩胛骨反肩关节置换术治疗肩胛骨肿瘤的疗效。.
UNASSIGNED: 2017年11月—2021年12月，采用3D打印全肩胛骨反肩关节置换术治疗5例肩胛骨肿瘤患者。男1例，女4例；年龄 44～59岁，平均50.4岁。软骨肉瘤2例，高级别骨肉瘤1例，肺癌肩胛骨转移1例，韧带样纤维瘤病复发1例。病程4～8个月，平均5.8个月。根据美国肌肉骨骼肿瘤学会（MSTS）肩胛带分区标准，4例肿瘤累及S1、S2区，1例累及S2区。肿瘤直径4.2～11.2 cm，平均6.1 cm。记录手术时间、术中出血量及输血情况。随访期间采用MSTS评分评价患者肢体功能恢复情况，观察有无肩部下垂、并发症发生以及肿瘤学结局等，影像学复查假体位置。.
UNASSIGNED: 手术时间155～230 min，平均189 min。术中出血量100～1 500 mL，中位数600 mL；其中2例术中分别输血800、1 850 mL。术后切口均Ⅰ期愈合，无感染等并发症发生。患者均获随访，随访时间4～22个月，平均13个月；其中2例患者因肿瘤全身多处转移和脏器衰竭，分别于术后8、15个月死亡。末次随访时，患者MSTS 评分为73%～83%，平均77.4%；患肩较健侧下沉2～4 cm，平均3 cm。影像学复查示随访期间无假体松动、脱位、断裂等并发症发生。.
UNASSIGNED: 3D打印全肩胛骨反肩关节置换术治疗肩胛骨肿瘤可获得良好肩关节功能及外观，患者接受度和满意度较高。.

OBJECTIVE: Reverse shoulder arthroplasty (RSA) is an effective surgery for severe shoulder joint diseases. Traditionally, the preoperative planning procedure of RSA is manually conducted by experienced surgeons, resulting in prolonged operating time and unreliable drilling paths of the prosthetic fixation screws. In this study, an automatic surgical planning algorithm for RSA was proposed to compute the optimal path of screw implantation.
METHODS: Firstly, a cone-shaped space containing alternative paths for each screw is generated using geometric parameters. Then, the volume constraint is applied to automatically remove inappropriate paths outside the bone boundary. Subsequently, the integral of grayscale value of the CT is used to evaluate the bone density and to compute the optimal solution. An automatic surgical planning software for RSA was also developed with the aforementioned algorithms.
RESULTS: Twenty-four clinical cases were used for preoperative planning to evaluate the accuracy and efficiency of the system. Results demonstrated that the angles among the prosthetic fixation screws were all within constraint angle(45°), and the stability rate of the planned prosthesis was 94.92%. The average time for the automatic planning algorithm was 4.39 s, and 83.96 s for the whole procedure. Repetitive experiments were also conducted to demonstrate the robustness of our system, and the variance of the stability coefficient was 0.027%.
CONCLUSIONS: In contrast to the cumbersome manual planning of the existing methods for RSA, our method requires only simple interaction operations. It enables efficient and precise automatic preoperative planning to simulate the ideal placement of the long prosthetic screws for the long-term stability of the prosthesis. In the future, it will have great clinical application prospects in RSA.

Introduction: Reverse shoulder arthroplasty (RSA) is becoming popular in the treatment of complex proximal humeral fractures (PHFs). Greater tuberosity healing may influence functional outcomes and range of motion (ROM) of shoulder after RSA. In addition, the design of prosthesis may impact the healing rate of greater tuberosity. The purpose of this study is to know: (1) does the healing of greater tuberosity affect the functional outcomes and ROM of shoulder? and (2) does the design of prosthesis affect the healing rate of greater tuberosity? Materials and Methods: PubMed, Ovid/Embase, and the Cochrane Library were searched for studies comparing the clinical outcomes between the healed groups and the non-healed groups after RSA. Results: For functional outcomes, the results showed that the healed group had better Constant scores (CSs) (p < 0.0001). For ROM, the healed group showed better flexion (p < 0.0001), abduction (p = 0.02), and external rotation (p < 0.00001) of shoulder. For the design of prosthesis, the mean healing rate of greater tuberosity (82.7%) in patients with fracture-dedicated prosthesis was higher than those (63.0%) in patients with standard prosthesis. Subgroup analyses showed that the CS (p = 0.12) and abduction (p = 0.96) of patients using fracture-dedicated prostheses were not different between the healed groups and the non-healed groups. Meta-regression showed that there was no significant relationship between the design of prosthesis and CS (p = 0.312), flexion (p = 0.422), or external rotation (p = 0.776). Conclusion: Our meta-analysis showed that the healed groups could obtain better functional outcomes and ROM than the non-healed groups. In addition, fracture-dedicated prostheses promoted the healing rate of greater tuberosity. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020157276, PROSPERO: CRD42020157276.

UNASSIGNED: Despite the success of reverse shoulder arthroplasty (RSA), complication rates remain high (13% to 25%), due to instability, infection, and glenoid component loosening, which can lead to revision. The aim of the present study was to report the early clinical outcomes of RSA using a new hybrid baseplate design, in comparison with the literature on other common RSA baseplates.
UNASSIGNED: The authors retrospectively analyzed the records of 142 patients (142 shoulders) who underwent primary RSA using a hybrid baseplate design by the senior surgeons between May 2014 and December 2018. Preoperative and postoperative assessments included the Constant score (CS) and range of motion, including active forward elevation, external rotation, and internal rotation.
UNASSIGNED: Of the initial cohort of 142 patients, 13 were lost to follow-up (8.6%), 2 died (1.3%), and 8 required reoperations with implant removal (5.3%). The remaining 119 patients comprised 71 women (60%) and 48 men (40%), aged 73.6 ± 7.3 years at index surgery, 43 of whom required bony increased offset (36%). At a minimum follow-up of 2 years, the CS improved by 37.3 ± 16.1, active forward elevation increased by 51.2° ± 38.1°, external rotation increased by 16.4° ± 25.0°, and internal rotation increased by 1.5 ± 3.2.
UNASSIGNED: At a minimum follow-up of 2 years after RSA using a new hybrid baseplate system, the CS and range of motion were satisfactory and comparable to those in recent systematic reviews. The findings of this study suggest that this hybrid baseplate system provides satisfactory outcomes in the short term, although longer follow-up studies are needed to validate its long-term efficacy.