Radiographic patterns of osteoporotic proximal humerus fractures

Predicting Proximal Humerus Fracture Mechanical Complications: Are Computed Tomography Hounsfield Units the Answer?

INTRODUCTION

The purpose was to determine whether computed tomography (CT) Hounsfield units (HU) as a proxy for bone quality can predict postoperative complications following surgical treatment of proximal humerus fractures.

METHODS

Sixty-six patients with 2-, 3-, or 4-part proximal humerus fractures who underwent surgical fixation at single institution and had complete radiographic data available were included. Radiographic measurements included the deltoid tuberosity index (DTI) on preoperative anterior-posterior shoulder radiographs, and the HU value from the surgical proximal humerus was determined by measuring the humeral head at the midaxial/coronal/sagittal CT image using a circle-type region of interest (≥35 mm 2 ). Postoperative complications recorded were implant failure, development of osteonecrosis, nonunion, and acute periprosthetic fracture. Patients with and without complications were statistically compared, and binary logistic regression was performed to determine whether preoperative proximal humerus CT HU were predictive of complications.

RESULTS

Eight patients (12.1%) developed 11 overall complications, with three patients experiencing multiple complications each. Complications included osteonecrosis (4), implant failure (5), nonunion (1), and acute periprosthetic fracture (1). No difference was observed in demographics or Neer or AO/OTA classification between those with and without complications. Patients with complications had markedly lower DTI and overall HU as well as HU in the coronal and sagittal planes. Regression analysis for average DTI demonstrated a higher DTI and had a 10 times decreased risk of complication ( P = 0.040, odds ratio = -10.5, 95% confidence interval, 0.000 to 0.616). Regression analysis for average total HU also found a higher HU associated with a decreased risk of complications ( P = 0.034, odds ratio = -0.020, 95% confidence interval, 0.980 to 0.962). Logistic regression analysis, including age, age-adjusted Charlson Comorbidity Index, mean DTI, and mean total HU, only found mean total HU to be notable within the model.

DISCUSSION

CT HU may identify patients with poorer bone quality and thus help predict postoperative complications.

LEVEL OF EVIDENCE

Diagnostic Level III.

Impact of augmentation strategy variations on the mechanical characteristics of patients with osteoporotic proximal humerus fractures with medial column instability

Introduction

Low bone density and lack of medial support are the two most important factors affecting the stability of locking plate fixation for osteoporotic proximal humeral fractures (PHFs). This study aimed to compare the biomechanical characteristics of PHILOS locking plates combined with calcar screws, bone cement, fibular allografts, and medial locking plate support strategies for treating osteoporotic PHFs with medial column instability.

Methods

A three-part osteoporotic PHF (AO 11-B3.2) model with metaphyseal loss was generated using 40 synthetic humeri and fixed via four distinct medial support strategies. All models were mechanically tested to quantify the mechanical characteristics. Subsequently, finite element models were created for each biomechanical test case. The stress distribution and displacement of the four different fixation structures were analyzed using finite element analysis.

Results

The results demonstrated that the PHILOS locking plate combined with the medial locking plate, exhibited the greatest stability when subjected to axial, shear, and torsional loading. Furthermore, the PHILOS locking plate combined with bone cement showed structural stability similar to that of the PHILOS locking plate combined with fibular allograft but with lower stress levels on the fracture surface.

Discussion

In conclusion, the PLP-MLP fixation structure showed superior biomechanical properties under axial, shear, and torsional loading compared to other medial support methods. Repairing the medial support when treating osteoporotic PHFs with medial column instability can enhance the mechanical stability of the fracture end in both the short and long term.

Proximal humeral bone density assessment and prediction analysis using machine learning techniques: An innovative approach in medical research

Background

Patients with fractures of the proximal humerus often local complications and failures attributed to osteoporosis. Currently, there is a lack of straight forward screening methods for assessing the extent of local osteoporosis in the proximal humerus. This study utilizes machine learning techniques to establish a diagnostic approach for evaluating local osteoporosis by analyzing the patient's demographic data, bone density, and X-ray ratio of the proximal humerus.

Methods

A cohort comprising a total of 102 hospitalized patients admitted during the period spanning from 2021 to 2023 underwent random selection procedures. Resulting in exclusion of 5 patients while enrolling 97 patients for analysis encompassing patient demographics, shoulder joint anteroposterior radiographs, and bone density information. Using the modified Tingart index methodology involving multiple measurements denoted as M1 through M4 obtained from humeral shafts. Within this cohort comprised 76 females (78.4 %) and 21 males (21.6 %), with an average age of 73.0 years (range: 43-98 years). There were 25 cases with normal bone density, 35 with osteopenia, and 37 with osteoporosis. Machine learning techniques were used to randomly divide the 97 cases into training (n = 59) and validation (n = 38) sets with a ratio of 6:4 using stratified random sampling. A decision tree model was built in the training set, and significant diagnostic indicators were selected, with the performance of the decision tree evaluated using the validation set. Multinomial logistic regression methods were used to verify the strength of the relationship between the selected indicators and osteoporosis.

Results

The decision tree identified significant diagnostic indicators as the humeral shaft medullary cavity ratio M2/M4, age, and gender. M2/M4 ≥ 1.13 can be used as an important screening criterion; M2/M4 < 1.13 was predicted as local osteoporosis; M2/M4 ≥ 1.13 and age ≥83 years were also predicted as osteoporosis. M2/M4 ≥ 1.13 and age <64 years or males aged between 64 and 83 years were predicted as the normal population; M2/M4 ≥ 1.13 and females aged between 64 and 83 years were predicted as having osteopenia. The decision tree's accuracy in the training set was 0.7627 (95 % CI (0.6341, 0.8638)), and its accuracy in the test set was 0.7895 (95 % CI (0.6268, 0.9045)). Multinomial logistic regression results showed that humeral shaft medullary cavity ratios M2/M4, age, and gender in X-ray images were significantly associated with the occurrence of osteoporosis.

Conclusion

Utilizing X-ray data of the proximal humerus in conjunction with demographic information such as gender and age enable the prediction of localized osteoporosis, facilitating physicians' rapid comprehension of osteoporosis in patients and optimization of clinical treatment plans.

Level of evidence

Level IV retrospective case study.

Rare finding of axillary artery dissection secondary to a proximal humerus fracture-dislocation: A case report

Case

Proximal humerus fractures are a relatively common injury, making up approximately 5 % of all extremity fractures. Concurrent damage to the axillary artery, however, is not a commonly associated trauma. We present a unique case of a proximal humerus fracture-dislocation resulting in an axillary artery dissection and upper extremity ischemia, requiring emergent vascular intervention.

Conclusion

Axillary artery injury secondary to a proximal humerus fracture-dislocation is a rare, but possibly devastating complication. A thorough physical examination to identify any neurovascular deficits is critical in determining an optimal and timely resolution.

Age-Related changes in the morphological features of medial column of the proximal humerus in the Chinese population

Background

Age-related changes in the medial column (MC) of the proximal humerus have a major impact on fracture management; however, the changes in the morphological features remain unclear. This study aimed to investigate the age-related changes in the morphological features of MC and present the morphological grading.

Methods

One hundred computed tomography (CT) images of the proximal humerus of 100 individuals (19-95 years) were retrospectively obtained. The individuals were categorized into five age groups to quantify the differences among different ages; the youngest group (18-44 years) served as the baseline group. Parameters of the morphological features were measured on CT images with multiplanar reconstruction based on an explicit definition of MC, including length, thickness, width, oblique thickness (DSM), humeral head diameter (DHM), and ratio (RSM) of DSM to DHM. The morphological grading of MC was presented based on the value of RSM deviating different standard deviations (SD) from the mean value in the baseline group.

Results

Significant negative correlations were observed between age and the morphological parameters of MC (r ranged from -0.875 to -0.926; all P < 0.05), excluding DHM (r = 0.081, P = 0.422). Significant differences in the values of morphological feature parameters were detected among the five age groups (all P < 0.001). The highest mean values of morphological feature parameters were observed in the youngest group (18-44 years), which decreased gradually with increasing age until the lowest mean values were observed in the oldest group (≥90 years) (all P < 0.05). The morphological features of MC were categorized into three grades based on the value of RSM deviating 1.5 SD or 3 SD from the mean value in the baseline group.

Conclusion

Our study shows that the parameter values of morphological features of MC decreased with increasing age. The morphological features of MC could be categorized into three grades. Our findings may provide a more comprehensive insight into age-related changes in the morphological features of MC that facilitate risk stratification and optimize the management of proximal humeral fractures.

Acetabular fractures in elderly

BACKGROUND

This study aimed to determine characteristics of acetabular fractures in the elderly by evaluating clinical course and computed tomography-based radiological features between low- and high-energy acetabular fractures.

METHODS

We reviewed 178 consecutive patients with acetabular fractures aged ≥60 years from six centers. Low-energy fractures (group 1) were identified in 23 (12.9%) patients and high-energy fractures (group 2) in 155 (87.1%) patients. We compared demographics, radiological findings, and clinical course between the groups.

RESULTS

Average age (70.6 vs. 67.8 years, p = 0.046) and ratio of females (47.8% vs. 23.2%, p = 0.021) were significantly higher in group 1 than in group 2. The Charlson comorbidity index was also higher in group 1, but no other demographics showed difference. More patients in group 2 than in group 1 underwent surgery (91.6% vs. 73.9%); however, more in group 1 underwent minimally invasive surgery (17.4% vs 4.5%). Anterior column-associated fracture patterns occurred in 91.4% and 38.7% of cases in groups 1 and 2, respectively. Most fractures were displaced (>2 mm); 68% of which were comminuted. Furthermore, 24.2% of the fractures had superior dome impaction, whereas 23.0% were associated with posterior wall impaction.

CONCLUSIONS

Patients who sustained low-energy acetabular fractures were mostly women, were older, and had more comorbidities. Radiological findings of low-energy acetabular fractures showed anterior column involvement associated with injury to the quadrilateral surface. Additionally, it was observed to be commonly combined with comminution and impacted fragments.

Incidence and Risk Factors for Pseudosubluxation of the Humeral Head Following Proximal Humerus Fracture

Background

Humeral head pseudosubluxation (HHPS) in relation to the glenohumeral joint is a common finding following fractures of the proximal humerus. The temporary inferior subluxation of the humeral head may be secondary to a transient axillary nerve neuropraxia, pain inhibition of the deltoid, or hemarthrosis or capsular disruption that alters the physiologically negative pressure in the glenohumeral joint. Despite the frequency of this finding, it is not well described in the literature. This study sought to describe the incidence, risk factors, and rate of resolution of HHPS following proximal humerus fracture.

Methods

The practice of two fellowship-trained shoulder and elbow surgeons was queried for proximal humerus fractures. Patient radiographs were reviewed at the time of injury and all subsequent follow-ups through one year after injury. Data collection included the presence of HHPS, type of fracture based on the Neer classification, operative vs. nonoperative management, and resolution of HHPS. Exclusion criteria included skeletally immature patients, fracture-dislocations, patients treated with reverse shoulder arthroplasty, inadequate follow-up, or those patients with incorrect International Classification of Diseases coding.

Results

The incidence of HHPS was 20.0% (103 out of 515 patients) overall. Patients who required surgical intervention were more likely to develop pseudosubluxation than those who were treated conservatively (P < .001). There was an increasing incidence of pseudosubluxation based on the Neer classification, with 0-part fractures demonstrating a 2.56% (2/78) rate, whereas 4-part fractures were found to have HHPS in 35.1% (20/57) of cases (P < .001). All patients were found to have resolution of their HHPS at the final follow-up or one year after injury. None of age, sex, obesity, or injury to the dominant arm was associated with the occurrence of HHPS. There was, however, a statistically significant difference in the body mass index of those who developed HHPS (28.4, ± 5.77) vs. those who did not (26.2, ± 5.32, P < .01).

Conclusion

This retrospective radiographic study is the largest to date investigating the incidence of HHPS following proximal humerus fracture and first to correlate with Neer classification and operative intervention. We found that HHPS occurs in one-fifth of acute proximal humerus fractures and resolves regardless of intervention. More complex fractures, including those with increasing Neer parts or requiring operative intervention, developed HHPS at higher rates than simpler fracture patterns. This study will help both general orthopedists as well as shoulder surgeons understand the epidemiology of HHPS and provide reassurance to patients that PS is a benign finding with expected spontaneous resolution by one year.

Patellar fractures in elderly patients: a multicenter computed tomography-based analysis

INTRODUCTION

This study aimed to demonstrate the characteristics of patellar fractures and evaluate clinical outcomes in elderly patients.

PATIENTS AND METHODS

Medical records of patients aged ≥ 60 years who presented with patellar fractures were retrospectively reviewed from an institutionally approved multicenter (five institutions) orthopedic database. Patient characteristics and fracture patterns were identified, and the clinical outcomes were investigated. We compared differences according to the injury mechanism (low- vs. high-energy).

RESULTS

A total of 202 patients [mean age, 69.4 years (range, 60-88 years); male, 89, female, 113] were included in this study. The mean follow-up period was 14.8 months (range 6-58 months), and 75% of the fractures were from low-energy injuries. According to the AO /OTA classification, the most common type was type C (136 cases, 67.3%; 33 cases, C1; 23, C2; and 80, C3), followed by type A (39 cases), type B (26 cases), and unclassified (1 case). The unclassified case was an intra-articular marginal impaction without cortical breakage. Computed tomography (CT) revealed that of the cases, 66.8% had an inferior pole involvement; 80.7%, a comminuted fragment; and 10.4%, an impacted fracture. A total of 166 fractures (82.2%) were treated surgically. The mean union time and range of motion were 13.1 weeks and 123.8° (range 30-150°), respectively. The Lysholm score was 82.1 ± 12.0, with 65.7% of the cases having excellent or good function. The complication rate was 12.4% (24 cases), including ten, four, two, and five cases of infection, fixation failure, nonunion, malunion, and pin migration, respectively. The reoperation rate was 26.4%.

CONCLUSION

Patellar fractures in the elderly were mostly from low-energy injuries, and types C3 and A1 were the most common. CT images demonstrated high rates of an inferior pole involvement and comminution. The complication and reoperation rates were relatively high.

Effect of Osteoporosis on Proximal Humerus Fractures

Introduction:

Proximal humerus fractures (PHF) constitute the majority of the most common osteoporotic fractures. Bone density measurements can affect treatment methods and outcomes. This study was aimed to investigate the effect of osteoporosis values, measured from direct radiographs, on fracture type, surgical outcomes.

Methods:

248 patients over 50 years of age who presented to Mersin City Hospital between 2017 and 2020 with proximal humeral fractures were retrospectively evaluated. The age and gender of the patients and the fracture types were evaluated according to the AO classification system from the direct radiographs obtained at the time of admission were recorded. The Tingart cortical thickness and deltoid tuberosity index (DTI) measurements were used to assess osteoporosis status in all patients. Postoperative and follow-up radiographs of 45 patients, treated with fixed-angle proximal humeral locking plate, were evaluated for radiographic results and their correlations with osteoporosis measurements were examined.

Results:

According to the demographic characteristics of the patients, 171 patients were female and 77 patients were male (F/M: 3/1), and mean age was 69.2 ± 11.66 (50-95). Considering the bone quality parameters in all patients, the mean Tingart value was 5.8 ± 1.6 mm and the mean DTI was 1.43 ± 0.17, where there was a correlation between the Tingart value and DTI (r = 0.810 and p < 0.001). Although there was a statistically significant relationship between the osteoporosis parameters and age and gender (p < 0.001 and p = 0.023, respectively), main AO fracture types were not related to osteoporosis (p < 0.05). In the operated group (n = 48, 19%), 19 patients (42%) showed poor outcomes, which were not associated with age and osteoporosis parameters.

Conclusion:

This study was concluded that osteoporosis parameters differ between genders and age groups in patients with PHF, however osteoporosis is not the main factor affecting the fracture type and surgical outcomes.

Proximal humeral nail for treatment of 3- and 4-part proximal humerus fractures in the elderly population: effective and safe in experienced hands

BACKGROUND

Optimal treatment of 3- and 4-part proximal humerus fractures (PHFs) remains controversial. Although commonly recommended for less comminuted PHFs, the outcomes of treatment with proximal humerus nailing (PHN) are more equivocal. The purpose of this study was to report on radiographic and clinical outcomes of patients undergoing PHN fixation of 3- and 4-part PHFs at minimum one-year follow-up. Our hypothesis was that the findings would demonstrate satisfactory radiographic and clinical outcomes, with low rates of complications and revision surgeries.

METHODS

Between 2008 and 2016, 121 patients with comminuted, low-energy, osteoporotic, PHFs underwent fixation via Targon PHN (Aesculap, Tuttlingen, Germany). Of these, 60 patients met inclusion and exclusion criteria and were included in this analysis (mean age 72; range 65-85). All completed a minimum 1-year follow-up (range 12.5-82 months). Patients with 3-part PHFs were compared to patients with 4-part PHFs. Clinical, radiographic, and functional outcomes were assessed at postoperative visits. Patient reported outcomes included pain, the American Shoulder and Elbow Surgeons (ASES) score and the Simple Shoulder Test (SST). Radiographic union and revision and complication rates were assessed.

RESULTS

Overall, 37 (62%) fractures were classified as Neer 3 and 23 (38%) were classified as Neer 4. Both groups achieved similar postoperative range of motion. Patients with 3-part fractures reported significantly lower postoperative pain (0.76 ± 1.8 vs. 1.65 ± 2.2, p = 0.0047). Patients with 3-part fractures reported significantly better ASES scores (82.4 ± 19.2 vs. 70.8 ± 21.9, p = 0.02) and non-statistically significant higher SST scores (8.4 ± 3.2 vs. 7.43 ± 3.8, p = 0.14). Adequate fracture union was achieved in 53 fractures (88.3%). Three patients (5%) had varus malunion or greater tuberosity displacement, one (1.7%) had mechanical failure, and three (5%) had radiographic evidence of avascular necrosis. Between groups, there was no difference in failure rates.

CONCLUSION

Proximal humeral nails can successfully be used by experienced surgeons in fixation of comminuted and displaced proximal humeral fractures in selected patients with osteoporosis. While patients with both 3- and 4-part fractures demonstrate fracture union with satisfactory outcomes, patients with 3-part fractures demonstrate significantly higher postoperative functional scores.

The impact of COVID-19 on shoulder and elbow trauma: an Italian survey

BACKGROUND

Because of the rapid spread of COVID-19, on March 8, 2020 Italy became a "protected area": people were told not to leave their homes unless it was essential. The aim of this study was to evaluate the activity of our trauma center, relative to shoulder and elbow, in the 30 days starting from March 8, 2020, the first day of restrictions in Italy, and to compare it with the same days of 2019 to weigh the impact of COVID-19 on shoulder and elbow trauma.

MATERIALS AND METHODS

Patients managed in our trauma center between March 8, 2020, and April 8, 2020 (COVID period), for shoulder and elbow trauma were retrospectively included and compared to patients admitted in the same period of 2019 (no-COVID period). Clinical records of all participants were examined to obtain information regarding age, sex, mechanism of injury, and diagnosis.

RESULTS

During the no-COVID period, 133 patients were admitted for a shoulder or elbow trauma; in the COVID period, there were 47 patients (65% less first aid). In the no-COVID and COVID period, patients with shoulder contusion totaled 60 (14.78% of all; male [M]: 34; female [F]: 26; mean age 51.8 years, range 18-88) and 11 (12.09% of all contusions; M: 7, F: 4; mean age 43 years, range 24-60), respectively. In the no-COVID period, 27 fractures (9.34% of all fractures) involved the shoulder, whereas 18 fractures (8.69%) were registered in the COVID period. In the no-COVID period, 14 elbow fractures were treated (4.8% of all fractures), compared with 4 in the COVID period. In the no-COVID and COVID periods, 6 patients (M: 5, F: 1; mean age 42 years, range 21-64) and 2 patients (M: 1, F: 1; mean age 29.5 years, range 24-35) reported having a feeling of momentary post-traumatic shoulder instability, and 0 and 1 patients (M: 1, F: 0; age 56 years), respectively, reported similar symptoms at the elbow. Finally, first or recurrent dislocations in the no-COVID period were 10, and in the COVID period, 7; elbow dislocations in the no-COVID period were 2, and in the COVID period, there were 3.

CONCLUSIONS

During the COVID period, we provided a reduced number of health services, especially for patients with low-energy trauma and for those who underwent sports and traffic accidents. However, during the COVID period, elderly subjects remain exposed to shoulder and elbow trauma due to low-energy (domestic) falls. The subsequent hospitalization of these patients has contributed to making it more difficult to manage the hospital wards that are partly occupied by COVID-19 patients.

The Circle-Fit Method Helps Make Reliable Cortical Thickness Measurements Regardless of Humeral Length

Background

Although proximal humerus strength/quality can be assessed using cortical thickness measurements (eg, cortical index), there is no agreement where to make them. Tingart and coworkers used measurements where the proximal endosteum becomes parallel, while Mather and coworkers used measurements where the periosteum becomes parallel. The new circle-fit method (CFM) makes 2 metaphyseal (M1-M2) and 6 diaphyseal (D1-D6) measurements referenced from humeral head diameter (HHD). However, it is unknown whether these locations correlate to humeral length (HL). Accordingly, we asked: (1) Does HHD, Tingart distance, and Mather distance correlate with HL? (2) What is the location of HHD, Tingart distance, and Mather distance as a percentage of HL? and (3) Which CFM D1-D6 locations correlate with Tingart and Mather distances?

Materials and Methods

Measurements made on cortical thickness (CT) scout views of 19 humeri (ages: 16-73 years) included HHD, distances from the superior aspect of the humerus to proximal Tingart and Mather locations, and HL.

Results

Intraclass correlation was excellent for CFM-HHD, poor for Tingart, and moderate for Mather. The CFM-HHD had a stronger correlation to HL than Tingart and Mather. Mean HHD was 15.5% (0.9%) of HL while Tingart was 27.0% (4.1%) and Mather was 23.2% (3.8%). Tingart distance corresponded to D2/D3 CFM locations while the Mather distance was similar to D1/D2.

Discussion

The CFM reliably correlates with HL and provides a stronger correlation and less variance between specimens than the Tingart or Mather Methods.

Conclusions

Because the CFM produces reliable percent of HL locations, it should be used to define locations for obtaining biomechanically relevant CT measurements such as cortical index. Stronger correlations of these CFM-based measurements with proximal humerus strength will be important for developing advanced algorithms for fracture treatment.