The influence of bone mineral density and cortical index on the complexity of fractures of the proximal humerus

Predicting the deltoid tuberosity index in proximal humerus fractures using fracture characteristics and patient age: development of the LBQ-PHF score

BACKGROUND

The aim of this study was to investigate (1) whether fracture pattern and age are associated with local bone quality (LBQ), and (2) whether a scoring system based on these variables is able to predict LBQ in proximal humerus fractures (PHF).

MATERIALS AND METHODS

A retrospective study was performed of all acute PHF at a Level 2 trauma center with plain radiographs and CT between June 2009 and March 2022. Local bone quality was measured by using the deltoid tuberosity index (DTI). In addition to age and gender, fracture morphology was categorized using the following classification systems: Neer, Resch, AO Foundation/Orthopaedic Trauma Association (AO/OTA), and Hertel/LEGO. Additionally, coronal head alignment was calculated by measuring the head-shaft angle.

RESULTS

Only the Resch classification system revealed a significant relationship between fracture type and bone quality, as there was a significant association between coronal head alignment and DTI (p = 0.001). Valgus head alignment was observed significantly more frequent in patients with low bone quality (p = 0.002). Multinomial logistic regression analysis revealed a significant relative risk ratio for age (RRR = 0.97, [95% CI, 0.94-1], p = 0.039) and a non-significant trend for DTI (RRR = 1.26, [95% CI, 0.96-1.64], p = 0.092) for occurrence of anatomic relative to valgus head alignment. Using a DTI cut-off value of 1.3 instead of 1.4, age and also varus head alignment were identified as significant predictors of LBQ (OR = 1.12, [95% CI, 1.1-1.15], p < 0.001; OR = 0.54, [95% CI, 0.3-0.96], p = 0.037). A scoring system called the LBQ-PHF score (local bone quality in proximal humerus fractures), developed based on these two variables was able to predict LBQ with a sensitivity of 79.2% and a specificity of 86.7%.

CONCLUSION

Age and coronal humeral head alignment are independent predictors of LBQ in PHF. A simple scoring system developed based on these variables is able to assess BQ with solid predictive characteristics.

Hounsfield units predicts the occurrence but not the patterns of proximal humerus fracture in the elderly patients

BACKGROUND

Increased incidence of fragility fractures of the proximal humerus has been reported. Proximal humerus Hounsfield unit (HU) measurements based on computed tomography (CT) scans of the shoulder can be used to evaluate bone mineral density (BMD). It is unknown whether HU values can predict the risk of proximal humerus osteoporotic fracture and /or fracture patterns. Therefore, the objectives of this study were to identify whether the HU value is associated with proximal humeral osteoporotic fracture risk, and whether or not it has an impact on the complexity of the fracture.

METHODS

We identified 60 + years old patients' CT scans between 2019 and 2021 according to the inclusion and exclusion criteria. All patients were divided into two groups based on the presence or lack of a fracture in the proximal humerus, meanwhile, patients with fractures were stratified into simple and comminuted fractures based on the Neer classification. HU values were calculated within the proximal humerus and compared between groups using the Student t-test, and receiver operating characteristic (ROC) curve analysis was used to determine the ability of HU values to predict fracture.

RESULTS

A total of 138 patients with proximal humerus fracture (PHF) including 62 simple PHFs and 76 complex PHFs and 138 non-fracture patients were enrolled in the study. The HU values decreased as age increased among all patients. Both male and female patients with PHF had significantly lower HU values compared with non-fracture patients, the area under the curve (AUC) of the ROC curve for males and females was 0.8 and 0.723 respectively. Nevertheless, no significant differences were found between simple and complex fractures of the proximal humerus in the HU values.

CONCLUSION

Decreasing HU values on CT may be an early warning sign of fracture potential, however, it was not a predictive factor for comminuted fracture of the proximal humerus.

Improving the Stability of a Hemipelvic Prosthesis Based on Bone Mineral Density Screw Channel and Prosthesis Optimization Design

In pelvic reconstruction surgery, the hemipelvic prosthesis can cause significant changes in stress distribution due to its high stiffness, and its solid structure is not suitable for osseointegration. The purpose of this study was to identify a novel bone mineral density screw channel and design the structure of the prosthesis so as to improve the distribution of stress, promote bone growth, and enhance the biomechanical properties of the prosthesis. The mechanical characteristics of bone mineral density screw and traditional screw were compared by finite element analysis method, and redesigned by topology optimization. The direction of the newly proposed screw channel was the posterolateral entrance of the auricular surface, ending at the contralateral sacral cape. Compared to the original group, the maximum stress of the optimized prosthesis was decreased by 24.39%, the maximum stress of the sacrum in the optimized group was decreased by 27.23%, and the average strain energy density of the sacrum in the optimized group was increased by 8.43%. On the surface of screw and connecting plate, the area with micromotion more than 28 μm is reduced by 12.17%. On the screw surface, the area with micromotion more than 28 μm is reduced by 22.9%. The newly determined screw channel and optimized prosthesis design can effectively improve the biomechanical properties of a prosthesis and the microenvironment of osseointegration. This method can provide a reference for the fixation of prostheses in clinical pelvic reconstruction.

Treatment of 2-Part Proximal Humeral Fractures in Osteoporotic Patients With Medial Calcar Instability Using a PHILOS Plate Plus an Allogeneic Fibula Inserted Obliquely - A Retrospective Study

INTRODUCTION

To date, there is little research assessing the efficacy of a proximal humeral internal locking system (PHILOS) plate plus an allogeneic fibula inserted obliquely in the treatment of 2-part proximal humerus fractures (PHFs) with calcar comminution in patients >60 years old with severe osteoporosis. The aim of this study was to retrospectively evaluate the outcomes of elderly patients with osteoporotic 2-part PHFs combined with medial column (calcar) instability or disruption who experienced a PHILOS plate plus an allogeneic fibula inserted obliquely.

MATERIALS AND METHODS

One hundred and twelve consecutive elderly patients with severe osteoporotic 2-part PHFs combined with calcar instability or disruption who were treated with a PHILOS plate plus an allogeneic fibula inserted obliquely were retrospectively identified from 3 tertiary medical centres during 2014-2019. The primary outcomes were the Constant scores and American Shoulder and Elbow Surgeons (ASES) scores; secondary outcome was the rate of key orthopaedic complications.

RESULTS

Median follow-up was 24 (15.3-27.6) months. Significant improvements in the median Constant scores were observed (39 [26-58 points] prior to surgery vs 81 [67-95 points] at final follow-up). The median ASES scores improved from 43 (26-64 points) prior to surgery to 83 (65-96 points) at final follow-up. The percentage of key orthopaedic complications was 25.6% (22/86). Four (4.7%) cases had loss of reduction, 4 (4.7%) experienced aseptic loosening, 1 (.8%) had non-union, 4 (4.7%) suffered a periprosthetic fracture, 3 (3.5%) experienced a revision surgery, 1 (.8%) had a dislocation and 5 (5.8%) suffered an unbearable shoulder pain.

CONCLUSION

For elderly patients with osteoporotic 2-part PHFs combined with calcar instability or disruption, PHILOS plate combined with an allogeneic fibula inserted obliquely might have recognisable advantages in decreasing the loss of fixation and preventing medial calcar collapse.

Cortical bone thickness predicts the quantitative bone mineral density of the proximal humerus

Cortical thickness determined at the humerus can serve as an easy and reliable screening tool to predict the local bone status when quantitative bone mineral density (BMD) measurements are not available. It can therefore serve as a rapid screening tool in fragility fractures to identify patients requiring further diagnostic or osteoporosis treatment.

INTRODUCTION

Quantitative bone mineral density (BMD) of the humerus is difficult to determine but relevant for osteoporosis and fracture treatment. Dual-energy X-ray absorptiometry (DXA) of the femur and lumbar spine overestimates the humeral BMD and is not ubiquitously available. Therefore, this study evaluated whether the cortical bone thickness (CBT) of the humerus or DXA of the forearm is able to predict humeral BMD.

METHODS

Humeral BMD of 54 upper cadaver extremities (22 pairs, 10 single) (19-90 years) was determined by high-resolution peripheral-quantitative-computed-tomography (HR-pQCT) (volumetric BMD (vBMD)) and DXA (areal BMD (aBMD)) of the proximal humerus and distal forearm. Average and gauge cortical bone thickness (CBTavg/ CBTg) of the humeral diaphysis was determined from standard radiographs (XR) and computed-tomography (CT) and compared to the humeral BMD. Pearson (r) and intraclass-correlation-coefficients (ICC) were used to compare results and rater-reliability.

RESULTS

CBTavg from XR strongly correlated with the humeral BMD (r = 0.78 aBMD (DXA) and r = 0.64 vBMD (HR-pQCT) (p < 0.0001)). The CBTg revealed a weaker correlation (r = 0.57 aBMD and r = 0.43 vBMD). CBT derived from XR strongly correlated to those from the CT (r = 0.82-0.90) and showed an excellent intra- and inter-rater correlation (ICC 0.79-0.92). Distal forearm aBMD correlated well with the humeral aBMD (DXA) (r = 0.77) and paired specimens highly correlated to the contralateral side (humerus r = 0.89, radius r = 0.97).

CONCLUSIONS

The CBTavg can reliably be determined from standard radiographs and allows a good prediction of quantitative humeral bone mineral density (aBMD or vBMD) if measurements are not available. Furthermore, the distal forearm or the contralateral humerus can serve as a side to estimate the BMD if the ipsilateral side is impaired.

Fractures of the proximal- and middle-thirds of the humeral shaft should be considered as fragility fractures

Aims

The aim of this study was to determine the current incidence and epidemiology of humeral diaphyseal fractures. The secondary aim was to explore variation in patient and injury characteristics by fracture location within the humeral diaphysis.

Methods

Over ten years (2008 to 2017), all adult patients (aged ≥ 16 years) sustaining an acute fracture of the humeral diaphysis managed at the study centre were retrospectively identified from a trauma database. Patient age, sex, medical/social background, injury mechanism, fracture classification, and associated injuries were recorded and analyzed.

Results

A total of 900 fractures (typical 88.9%, n = 800/900; pathological 8.3%, n = 75/900; periprosthetic 2.8%, n = 25/900) were identified in 898 patients (mean age 57 years (16 to 97), 55.5% (n = 498/898) female). Overall fracture incidence was 12.6/100,000/year. For patients with a typical fracture (n = 798, mean age 56 years (16 to 96), 55.1% (n = 440/798) female), there was a bimodal distribution in men and unimodal distribution in older women (Type G). A fall from standing was the most common injury mechanism (72.6%, n = 581/800). The majority of fractures involved the middle-third of the diaphysis (47.6%, n = 381/800) followed by the proximal- (30.5%, n = 244/800) and distal-thirds (n = 175/800, 21.9%). In all, 18 injuries (2.3%) were open and a radial nerve palsy occurred in 6.7% (n = 53/795). Fractures involving the proximal- and middle-thirds were more likely to occur in older (p < 0.001), female patients (p < 0.001) with comorbidities (p < 0.001) after a fall from standing (p < 0.001). Proximal-third fractures were also more likely to occur in patients with alcohol excess (p = 0.003) and to be classified as AO-Orthopaedic Trauma Association type B or C injuries (p < 0.001).

Conclusion

This study updates the incidence and epidemiology of humeral diaphyseal fractures. Important differences in patient and injury characteristics were observed based upon fracture location. Injuries involving the proximal- and middle-thirds of the humeral diaphysis should be considered as fragility fractures. Cite this article: Bone Joint J 2020;102-B(11):1475–1483.

Fragility Fracture Prevention-Implementing a Fracture Liaison Service in a High Volume Orthopedic Hospital

Fragility fractures pose a serious threat to patient health, quality of life, and healthcare sustainability. In order to reduce their clinical, social, and economic burden, a Fracture Liaison Service (FLS) was introduced in a high volume orthopedic hospital in 2017. The purpose of this retrospective observational study is to describe the FLS protocol, introduce its preliminary outcomes, and provide an early evaluation in light of international guidelines and recommendations. All the performances suggested by the International Osteoporosis Foundation (IOF) are provided under the same institution by which a patient is admitted for surgery. Clinical indicators from patient history and administrative indicators from the hospital database have been used to estimate the spread of fragility fracture prevention and the degree of patient compliance to these programs. The research included 403 patients. Although, almost 1/3 were admitted for the second fragility fracture, only half received anti-osteoporotic treatment before it. The degree of prevention was even lower in the case of patients admitted for the first fragility fracture. The risk of being affected by a secondary fracture was seven times higher when patients did not attend any follow-up or diagnostic exam. In order to identify the main determinants of compliance with FLS and perform a cost-effectiveness analysis on a larger sample, it is fundamental to integrate data from different providers.