Prediction of Nonunion After Nonoperative Treatment of a Proximal Humeral Fracture

Trends in Shoulder Arthroplasty: A Narrative Review of Predominant Indications and the Most Commonly Employed Implant Designs

Background: Over the past few decades, shoulder arthroplasty has evolved rapidly, driven by a growing demand for surgical solutions to degenerative, traumatic, and irreparable rotator cuff-related pathologies, particularly in an aging but increasingly active population. Objective: This narrative review aims to examine the main clinical indications and the most commonly used implant designs, highlighting differences in functional outcomes, complication rates, and revision rates between anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA). Methods: Articles published between 2011 and 2025 were selected through PubMed and the Australian Joint Replacement Registry reports from 2023 and 2024. The included studies comprised randomized controlled trials, systematic reviews, and meta-analyses involving adult patients treated for primary osteoarthritis, proximal humerus fractures, and massive irreparable rotator cuff tears. Results: ATSA remains the preferred option in younger patients with an intact rotator cuff, due to superior outcomes in mobility and prosthesis longevity. However, glenoid component loosening remains a significant limitation. Initially reserved for irreparable cuff tears and complex fractures, RTSA has seen a progressive expansion of its indications, offering lower revision rates and satisfactory functional results, particularly in elderly patients. Recent prosthetic innovations include stemless implants, augmented glenoid components, and convertible platforms. Conclusions: The choice between ATSA and RTSA should be individualized, based on patient-specific factors such as age, rotator cuff integrity, functional demands, and bone quality. Advances in implant materials and design, together with improved patient selection, have significantly enhanced clinical outcomes.

Complications after reverse shoulder arthroplasty for proximal humerus nonunion

BACKGROUND

Proximal humerus nonunion is a challenging complication of fractures that can be treated surgically with either open reduction internal fixation (ORIF) or reverse total shoulder arthroplasty (RTSA). The few studies published on this subject have shown high rates of complications and revision surgery when RTSA has been performed for proximal humerus nonunion. The purpose of this study was to determine the rates of complications and revision of this procedure at our institution, as well as to identify any variables that may impact risks of complications and reoperations.

METHODS

A single-institution retrospective review of all patients who underwent RTSA for proximal humerus nonunion between 2005 and 2021 was performed. Nonunion was defined as imaging evidence of lack of union, at least 90 days after the index fracture. Patients with less than 1 year of clinical follow-up were excluded. Fifty patients were included, with the majority being female (78%). The mean age at time of RTSA was 71 (range: 54-86) years and most patients were initially treated nonoperatively (74%). Mean total follow-up was 49 (range: 11-130) months. Demographic and surgical variables were recorded. Primary outcomes were complications and reoperations. Complications were divided into surgical (those directly related to RTSA), or other (those unrelated to RTSA). Secondary outcomes included visual analog scale pain scores and range of motion.

RESULTS

A total of 17 shoulders (34%) sustained complications after revision shoulder arthroplasty, with 10 (20%) requiring reoperation. Six patients (12%) sustained dislocations and 5 (10%) had radiographic evidence of humeral loosening. No variables examined, including nonoperative vs. surgical management of the index fracture, prosthesis type, or management of tuberosities, influenced the risk of dislocation. Survivorship free from reoperation at 2 years was 73%. Younger age at time of RTSA and the presence of diabetes mellitus both increased the risk of reoperation significantly (P = .013 and P = .037, respectively). There was a trend towards increased risk of reoperation in patients who were treated with initial ORIF (hazard ratio = 2.95); however, this did not reach statistical significance (P = .088). Three patients (6%) sustained a periprosthetic fracture after a fall.

CONCLUSION

RTSA provides improved pain and function for properly selected patients with proximal humerus nonunion. Dislocation, humeral loosening, and reoperation rates remain high when RTSA is performed for nonunion compared to other diagnoses. In this study, younger age and diabetes mellitus increased the odds of reoperation. Every effort must be made to optimize implant stability and humeral component fixation when RTSA is performed for proximal humerus nonunion.

Intramedullary nailing of proximal humerus fractures does not achieve superior functional results to non-operative treatment in the long term

INTRODUCTION

Non-operative treatment (NOT) of proximal humerus fractures (PHF) has regained significance due to recent evidence. Additionally, positive outcomes of plate osteosynthesis and fracture arthroplasty prompt a reassessment of the role of intramedullary nailing (IMN). While favorable short and medium-term results have been documented following IMN, little is known regarding functional outcomes and quality of life in the long-term.

METHODS

Data from 180 patients with dislocated PHF of Neer types III, IV and V, treated at our level-I trauma center between 2004 and 2014 using IMN or NOT therapy, were scanned. Patients were re-evaluated after a minimum of 5 years to assess functional outcomes (age- and sex-adapted Constant Score, QuickDASH), quality of life (SF12), and complications or reoperations.

RESULTS

Out of the initially identified 180 patients, 51 were unavailable for follow-up (FU) and 71 had deceased during the FU period. Functional outcomes and quality of life was, therefore, assessed in 58 patients (30 IMN, 28 NOT) with an average age at injury of 68 years after a mean FU time of 10.3 ± 3.4 years. Epidemiological patient characteristics did not exhibit significant differences between the two groups (p > .05). The functional outcome assessed by age- and sex-adapted Constant Score (NOT: 74 ± 28; IMN: 68 ± 24; p = .438), QuickDASH (NOT: 25 ± 27; IMN: 31 ± 23; p = .374) or quality of life using the SF12 (p > .05) revealed no significant disparities in long-term outcomes between the treatment groups. 10 of 30 patients in the IMN group underwent surgical revision to address complications, exceeding mere implant removal. Conversely, no patient in the NOT group underwent a revision surgery during the FU period.

CONCLUSIONS

In the long-term, functional and quality of life-related outcomes of IMN did not diverge significantly from those of NOT, while causing a higher incidence of follow-up interventions.

Do multiple fractures affect risk of fixation failure after surgical treatment of midshaft clavicle fracture? A retrospective cohort study

BACKGROUND

Surgical treatment of midshaft clavicle fractures is associated with quick recovery and low risk of non-union. However, fixation failure may occur in case of severe comminution fractures. Moreover, clinical outcomes may be affected when clavicle fractures occur in combination with other injuries, particularly those involving the lower extremities, as the use of crutches or walkers may hinder the process of rehabilitation by adding strain on the acromioclavicular (AC) joint, resulting in possible fixation failure. This study aims to identify risk factors for fixation failure of midshaft clavicle fractures and elucidate the role of combined fractures in treatment outcomes.

METHODS

This study included patients diagnosed with midshaft clavicle fractures who underwent initial surgery between January 2012 and November 2021 at a designated regional trauma center hospital. Retrospective evaluation of fixation failure was carried out in 352 patients with midshaft clavicle fractures using standard clinical evaluation protocols and conventional radiographs. The prevalence of fixation failure and the effects of several demographic variables on the risk of fixation failure and non-union were examined. Multivariate logistic regression analysis was carried out to identify independent risk factors for fixation failure.

RESULTS

Fixation failure occurred in 40 patients (11.4%). Multivariate analysis identified comminution [odds ratio (OR) 3.532, p value = 0.003, 95% confidence interval (CI) 1.55-8.05)] and fewer number of screws (OR 0.223, p value = 0.022, 95% CI 0.06-0.80) as risk factors for fixation failure. Surgical techniques using wire cerclage reduced the chances of fixation failure in comminuted fractures (OR 0.63, p value = 0.033, 95% CI 0.05-0.80). Combined fractures that required rehabilitation using walkers or crutches increased the risk of non-union (OR 19.043, p value = 0.032, 95% CI 1.28-282.46).

CONCLUSIONS

Additional fixation of comminuted fractures using cerclage can reduce the risk of treatment failure, while multiple fractures or rehabilitation for ambulation increases the risk of the same.

LEVEL OF EVIDENCE

III.

The selective norepinephrine reuptake inhibitor reboxetine promotes late-stage fracture healing in mice

Impaired fracture healing is of high clinical relevance, as up to 15% of patients with long-bone fractures display non-unions. Fracture patients also include individuals treated with selective norepinephrine reuptake inhibitors (SNRI). As SNRI were previously shown to negatively affect bone homeostasis, it remained unclear whether patients with SNRI are at risk of impaired bone healing. Here, we show that daily treatment with the SNRI reboxetine reduces trabecular bone mass in the spine but increases cortical thickness and osteoblast numbers in the femoral midshaft. Most importantly, reboxetine does not impair bone regeneration in a standardized murine fracture model, and even improves callus bridging and biomechanical stability at late healing stages. In sum, reboxetine affects bone remodeling in a site-specific manner. Treatment does not interfere with the early and intermediate stages of bone regeneration and improves healing outcomes of the late-stage fracture callus in mice.

Outcomes of Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture Versus Rotator Cuff Arthropathy

INTRODUCTION

Reverse total shoulder arthroplasty (RSA) is used to treat a variety of shoulder-related pathologies. This study compared medium-term clinical outcomes of less than 10-year follow-up in patients treated with RSA for proximal humerus fracture (PHF) versus rotator cuff arthropathy (RCA).

METHODS

This retrospective review was conducted at two tertiary care centers, in which self-reported clinical outcomes were assessed using four validated instruments, that is, American Shoulder and Elbow Society (ASES) score, Shoulder Pain and Disability Index (SPADI), visual analog scale (VAS), and shoulder subjective value (SSV). Statistical analyses were performed using linear or logistic regression with generalized estimating equations.

RESULTS

Of the 189 patients included in this study, 70 were treated for fracture and 119 for RCA. At a mean postoperative follow-up of 6.4 years, the means were 79.7 for ASES score, 20.8 for SPADI-Total, 0.8 for VAS, and 77.1 for SSV. After adjusting models for covariates, there was no significant difference in average SSV (P = 0.7), VAS (P = 0.7) or SPADI-Pain (P = 0.2) between PHF and RCA cohorts; however, the RCA cohort reported significantly better outcomes in ASES scores (P = 0.002), SPADI-Disability (P < 0.0001), and SPADI-Total (P = 0.0001).

DISCUSSION

Patients with RCA and PHF treated with RSA achieved similar medium-term outcomes in several domains, particularly postoperative pain levels; however, patients with PHF reported greater perceived disability. RSA is an effective pain-controlling procedure, but patients may have variable functional outcomes based on the indication for surgery.

The Translated Proximal Humerus Fracture: A Comparison of Operative and Nonoperative Management

OBJECTIVES

To report on the long-term outcomes of the management of translated proximal humerus fractures.

DESIGN

A prospective cohort study was conducted from January 2010 to December 2018.

SETTING

Academic Level 1 trauma center.

PARTICIPANTS/PATIENTS

A total of 108 patients with a proximal humerus fracture with ≥100% translation, defined as no cortical bony contact between the shaft and humeral head fragments, were included.

INTERVENTION

Patients were managed nonoperatively with sling immobilization or with operative management as determined by the treating surgeon.

MAIN OUTCOME MEASURES

Outcome measures were the Oxford Shoulder Score, EQ-5D-5L, return to work, and radiological outcomes. Complications recorded included further surgery, loss of position/fixation, nonunion/malunion, and avascular necrosis.

RESULTS

Of the 108 patients, 76 underwent operative intervention and 32 were managed nonoperatively. The mean (SD) age in the operative group was 54.3 (±20.2) years and in the nonoperative group was 73.3 (±15.3) years ( P < 0.001). There was no association between Oxford Shoulder Score and management options (mean 38.5 [±9.5] operative versus mean 41.3 [±8.5] nonoperative, P = 0.48). Operative management was associated with improved health status outcomes; EQ-5D utility score adjusted mean difference was 0.16 (95% CI, 0.04-0.27; P = 0.008); EQ-5D VAS adjusted mean difference was 19.2 (95% CI, 5.2-33.2; P = 0.008). Operative management was associated with a lower odds of nonunion (adjusted OR 0.30; 95% CI, 0.09-0.97; P = 0.04), malunion (adjusted OR 0.14; 95% CI, 0.04-0.51; P = 0.003), and complications (adjusted OR 0.07; 95% CI, 0.02-0.32; P = 0.001).

CONCLUSION

Translated proximal humerus fractures with ≥100% displacement demonstrate improved health status and radiological outcomes after surgical fixation.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Utility of Routine Follow-up Radiographs in the Nonoperative Management of Proximal Humerus Fractures in Patients 65 Years and Older

Whereas prior studies have aimed to define the utility of routine radiographs for the closed treatment of upper extremity fractures, it remains uncertain whether routine radiographs influence management decisions for nonoperative treatment of proximal humerus fractures (PHFs). The purpose of this investigation was to assess the utility of routine radiographic monitoring of closed PHFs in elderly patients initially indicated for nonoperative treatment. We identified all patients 65 years and older who had a PHF from 2016 to 2019. We excluded cases of pathologic fractures or peri-prosthetic fractures, nonunion, malunion, cases with insufficient follow-up, and cases for which surgery was indicated either in the emergency department or at the first orthopedic visit. After applying these exclusion criteria, 402 cases remained. We recorded baseline demographics and fracture descriptions and noted any conversion to operative treatment after the initial office visit. Two-part fractures were most common (56%). Of the 402 fractures indicated for nonoperative treatment, 21 (5%) were converted to operative management during the follow-up period. Nine fractures (2%) were converted to operative management within 30 days of the first office visit. Eight cases (2%) were converted to operative treatment more than 120 days after the initial office visit: 6 due to nonunion and 2 due to posttraumatic arthritis. For patients 65 years and older who undergo initial nonoperative treatment of a PHF, routine follow-up radiographs do not appear to alter management decisions. Given the risk and cost associated with routine radiographs, surgeons should consider forgoing these images in the absence of clinical concern. [Orthopedics. 2023;46(4):e244-e248.].

Impact of aberrant beam paths on antero-posterior shoulder radiographs in proximal humeral fractures

INTRODUCTION

Accurate radiographic assessment of proximal humeral fractures (PHF) is important as it influences clinical decision-making and predicts clinical outcome. Since aberrant radiographic views might influence the assessment of fracture displacement, it was the goal of this study to investigate the impact of aberrant beam paths on radiographic assessment of PHF.

MATERIALS AND METHODS

Ten consecutive patients with a displaced PHF, bilateral computed tomography (CT) scan, and a true clinical AP radiograph were included. Digitally reconstructed radiographs (DRRs) were generated and aberrant beam paths were simulated by rotation of ± 30° around the horizontal (flexion and extension) and vertical axis (internal and external rotation) by increments of 10°. Measurement of the neck-shaft-angle (NSA) and eccentric head index (EHI) addressed humeral angulation and offset, respectively. Paired comparisons determined the influence of aberrant beam paths on both measurements between incremental altered views, and between clinical and digital true AP views. Descriptive statistics assessed the change in Neer classification and recommended treatment.

RESULTS

True AP DRRs approximated the clinical true AP view by a mean difference of 2° for NSA, and a mean difference of 0.12 for EHI. NSA in injured shoulders was most susceptible to malrotation around the vertical axis (p < 0.03), with largest differences seen for internal rotation. Aberrant projections in extension had no influence on NSA (p > 0.70), whereas flexion of ≥ 20° and 30° demonstrated differences in injured and uninjured shoulders, respectively (p < 0.05). EHI was only influenced by malrotation in internal rotation in uninjured shoulders (p < 0.03). Alterations in Neer type occurred at 30° of malrotation in 5 cases, with a change in recommended treatment in 2.

CONCLUSIONS

Humeral angulation and offset measurements on AP radiographs are more susceptible to aberrant beam paths in fractured humeri. Altered radiographic beam paths around the vertical axis showed the most substantial influence on the assessment of PHF, with angular measurements demonstrating larger differences then offset measurements. Beam path alterations of 30° can influence the Neer classification, and might influence fracture displacement-based decisions.

Bone Healing Gone Wrong: Pathological Fracture Healing and Non-Unions-Overview of Basic and Clinical Aspects and Systematic Review of Risk Factors

Bone healing is a multifarious process involving mesenchymal stem cells, osteoprogenitor cells, macrophages, osteoblasts and -clasts, and chondrocytes to restore the osseous tissue. Particularly in long bones including the tibia, clavicle, humerus and femur, this process fails in 2-10% of all fractures, with devastating effects for the patient and the healthcare system. Underlying reasons for this failure are manifold, from lack of biomechanical stability to impaired biological host conditions and wound-immanent intricacies. In this review, we describe the cellular components involved in impaired bone healing and how they interfere with the delicately orchestrated processes of bone repair and formation. We subsequently outline and weigh the risk factors for the development of non-unions that have been established in the literature. Therapeutic prospects are illustrated and put into clinical perspective, before the applicability of biomarkers is finally discussed.

Functional Outcome After Nonoperative Treatment of a Proximal Humeral Fracture in Adults

BACKGROUND

The functional outcome following nonoperative treatment of a proximal humeral fracture and the factors that influence it are poorly defined. We aimed to prospectively assess patient-reported outcome measures (PROMs) in a patient cohort at 1 year after the injury.

METHODS

In this study, 774 adult patients sustaining a proximal humeral fracture completed PROM assessments, including the Oxford Shoulder Score (OSS), the EuroQol-5 Dimensions-3 Levels (EQ-5D-3L), and visual analog scale (VAS) assessments of pain, health, and overall treatment satisfaction at 1 year. The mean patient age was 65.6 years, and 73.8% of patients were female. The influences of demographic and fracture measurements and complications on the OSS and EQ-5D-3L were assessed.

RESULTS

The 1-year mean scores were 33.2 points (95% confidence interval [CI], 32.1 to 34.2 points) for the OSS and 0.58 (95% CI, 0.55 to 0.61) for the EQ-5D-3L. There was considerable heterogeneity in the reported scores, and the 3 demographic variables of higher levels of dependency, higher levels of social deprivation, and a history of affective (mood) disorder were most consistently associated with poorer outcomes, accounting for between 37% and 43% of the score variation. The initial fracture translation potentially leading to nonunion accounted for 9% to 15% of the variation, and a displaced tuberosity fracture was also predictive of 1% to 4% of the outcome variation. There was evidence of a ceiling effect for the OSS, with 238 patients (30.8%) having a score of ≥47 points but a mean outcome satisfaction of only 72.9 points, and this effect was more pronounced in younger, active individuals. At the other end of the spectrum, 239 patients (30.9%) reported an OSS of ≤24 points, and 120 patients (15.5%) had a "worse-than-death" EQ-5D-3L score.

CONCLUSIONS

Nonoperative treatment of proximal humeral fractures produces considerable variation in shoulder-specific and general health outcomes at 1 year, and a substantial proportion of patients have poor perceived functional outcomes. The outcome for the majority of less-displaced fractures is mainly influenced by preexisting patient-related psychosocial factors, although the fracture-related factors of displacement, nonunion, and tuberosity displacement account for a small but measurable proportion of the variation and the poorer outcomes in the minority with more severe injuries.

LEVEL OF EVIDENCE

Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Dual-Targeted Nanoplatform Regulating the Bone Immune Microenvironment Enhances Fracture Healing

The immune system and skeletal system are closely linked. Macrophages are one of the most important immune cells for bone remodeling, playing a prohealing role mainly through M2 phenotype polarization. Baicalein (5,6,7-trihydroxyflavone, BCL) has been well documented to have a noticeable promotion effect on M2 macrophage polarization. However, due to the limitations in targeted delivery to macrophages and the toxic effect on other organs, BCL has rarely been used in the treatment of bone fractures. In this study, we developed mesoporous silica and Fe₃O₄ composite-targeted nanoparticles loaded with BCL (BCL@MMSNPs-SS-CD-NW), which could be magnetically delivered to the fracture site. This induced macrophage recruitment in a targeted manner, polarizing them toward the M2 phenotype, which was demonstrated to induce mesenchymal stem cells (MSCs) toward osteoblastic differentiation. The mesoporous silicon nanoparticles (MSNs) were prepared with surface sulfhydrylation and amination modification, and the mesoporous channels were blocked with β-cyclodextrin. The outer layer of the mesoporous silicon was added with an amantane-modified NW-targeting peptide to obtain the targeted nanosystem. After entering macrophages, BCL could be released from nanoparticles since the disulfide linker could be cleaved by intracellular glutathione (GSH), resulting in the removal of cyclodextrin (CD) gatekeeper, which is a key element in the pro-bone-remodeling functions such as anti-inflammation and induction of M2 macrophage polarization to facilitate osteogenic differentiation. This nanosystem passively accumulated in the fracture site, promoting osteogenic differentiation activities, highlighting a potent therapeutic benefit with high biosafety.