A new classification of impacted proximal humerus fractures based on the morpho-volumetric evaluation of humeral head bone loss with a 3D model

A prognostic classification of proximal humerus fractures: the cephalic extension staging

PURPOSE

Recent publications emphasized the role of dorsomedial metaphyseal extension of humeral head as predictor of ischemia after complex proximal humerus fractures (PHFs). We evaluated on preoperative 3D CT scan of PHFs the surface of this metaphyseal extension and its prognostic value on the occurrence of avascular necrosis (AVN).

METHODS

We followed a series of 25 fixations of complex PHF which had a preoperative 3D CT scan and measured the surface area of the posterior metaphyseal extension (PME) of the head. Using approximations, we calculated the ratio between the PME surface area (PMS) and the articular surface area of the head (HS). The PMS/HS ratio was analyzed against the risk of AVN.

RESULTS

The measurement of the PMS/HS ratio emphasizes the significance of PME. The incidence of AVN is correlated with the magnitude of PME. Therefore, we include the PME as a fifth element in the characterization of complex PHFs and we propose a 4-stage prognostic classification based on the number of extensions of the humeral head. The head may have 3 extensions: posteromedial (PME), lesser tuberosity (LTE) and greater tuberosity (GTE). The risk of AVN decreases with the number of extensions of the head.

CONCLUSION

Our study demonstrates a correlation between the occurrence of AVN and the size of PME in complex PHF cases. We propose a four-stage classification system to facilitate treatment decision-making between fixation and prosthesis.

Intramedullary Nail for Treatment of Proximal Humeral Fracture: A Credible Fixation in Comminuted Calcar

OBJECTIVE

Restoration of the medial support is especially important for the treatment of proximal humeral fractures. The objective of this study was to investigate the radiographic and clinical outcomes of intramedullary nail fixation with a special focus on the presence of calcar comminution.

METHODS

In this retrospective study of patients with displaced proximal humeral fractures that were treated by intramedullary nail between January 2018 and July 2021, fracture morphology and the calcar integrity were noted on preoperative radiographs. Patients were divided into two groups according to calcar integrity. During follow-up, radiological assessment and functional outcome, including the deltoid tuberosity index (DTI), neck shaft angle (NSA), visual analog scale (VAS), the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST) score, active and passive range of motion, were performed. A Student t-test and univariate logistic regression analysis was used.

RESULTS

A total of 83 patients (54 female, 29 male) had complete follow-up (average, 12.8 months; range, 10 to 33 months) and functional assessment in our study. The average age was 58.6 years (range, 20 to 89 years). The mean loss of NSA was 4° (range, 0°-12°) and no significant difference was found between two groups (p = 0.27). DTI had an average of 1.50 ± 0.19 (range 1.13-2.04). Patients with intact calcar achieved greater range of forward elevation (129.06 ± 11.91 vs. 121.05 ± 11.97, p = 0.01), and higher SST scores (8.61 ± 1.85 vs. 7.37 ± 2.22, p = 0.02). Two groups showed similar outcomes in VAS, ASES score, and range of abduction. One patient demonstrated a proximal interlocking screw cutting through and osteonecrosis of the humeral head, who underwent a second surgery for screw removal. There were no cases of infection, malunion, nonunion, nerve injury, subacromial impingement, or rotator cuff tear during the study period.

CONCLUSION

Intramedullary nail can favorably be used to manage proximal humeral fractures with good early radiographic and functional outcomes, even for those with comminuted calcar.

Three-Dimensional Measurement of Proximal Humerus Fractures Displacement: A Computerized Analysis

Neer's classification for proximal humerus fractures (PHFs) uses 10 mm and 45° thresholds to distinguish displaced fragments. While this system was originally developed referencing 2D X-rays, fracture displacements occur in three dimensions. Our work aimed to develop a standardized and reliable computerized method for measuring PHF 3D spatial displacements. CT scans of 77 PHFs were analyzed. A statistical shape model (SSM) was used to generate the pre-fracture humerus. This predicted proximal humerus was then used as a "layer" to manually reduce fragments to their native positions and quantify translation and rotation in three dimensions. 3D computerized measurements could be calculated for 96% of fractures and revealed that 47% of PHFs were displaced according to Neer's criteria. Valgus and varus head rotations in the coronal plane were present in 39% and 45% of cases; these were greater than 45° in 8% of cases and were always associated with axial and sagittal rotations. When compared to 3D measurements, 2D methods underestimated the displacement of tuberosity fragments and did not accurately assess rotational displacements. The use of 3D measurements of fracture displacement is feasible with a computerized method and may help further refine PHF analysis and surgical planning.

Influence of preoperative simulation on the reduction quality and clinical outcomes of open reduction and internal fixation for complex proximal humerus fractures

PURPOSE

Proximal humerus fractures (PHFs) are common. With the development of locking plates, open reduction and internal fixation (ORIF) of the proximal humerus can provide excellent clinical outcomes. The quality of fracture reduction is crucial in the locking plate fixation of proximal humeral fractures. The purpose of this study was to determine the impact of 3-dimensional (3D) printing technology and computer virtual technology assisted preoperative simulation on the reduction quality and clinical outcomes of 3-part and 4-part proximal humeral fractures.

METHOD

A retrospective comparative analysis of 3-part and 4-part PHFs undergoing open reduction internal fixation was performed. Patients were divided into 2 groups according to whether computer virtual technology and 3D printed technology were used for preoperative simulation: the simulation group and the conventional group. Operative time, intraoperative bleeding, hospital stay, quality of fracture reduction, Constant scores, American Society for Shoulder and Elbow Surgery (ASES) scores, shoulder range of motion, complications, and revision surgeries were assessed.

RESULTS

This study included 67 patients (58.3%) in the conventional group and 48 patients (41.7%) in the simulation group. The patient demographics and fracture characteristics were comparable in these groups. Compared with the conventional group, the simulation group had shorter operation time and less intraoperative bleeding (P < 0.001, both). Immediate postoperative assessment of fracture reduction showed a higher incidence of greater tuberosity cranialization of < 5 mm, neck-shaft angle of 120° to 150°, and head shaft displacement of < 5 mm in the simulation group. The incidence of good reduction was 2.6 times higher in the simulation group than in the conventional group (95% CI, 1.2-5.8). At the final follow-up, the chance of forward flexion > 120° (OR 5.8, 95% CI 1.8-18.0) and mean constant score of > 65 (OR 3.4, 95% CI 1.5-7.4) was higher in the simulation group than the conventional group, as well as a lower incidence of complications in the simulation group was obtained (OR 0.2, 95% CI 0.1-0.6).

CONCLUSIONS

This study identified that preoperative simulation assisted by computer virtual technology and 3D printed technology can improve reduction quality and clinical outcomes in treatment of 3-part and 4-part PHFs.

Therapeutic and prognostic predictive value of the Control Volume severity grade on proximal humerus fractures due to bone fragility

Background

The treatment of proximal humerus fracture complicated by bone fragility is still controversial. The aim of this study is to compare the Neer classification and the Control Volume severity grade for the accuracy in the selection of the type of treatment and for prognostic evaluation.

Materials and methods

We retrospectively collected the records of all patients admitted at the Emergency Department of our Institute, from 2013 to 2020, for a closed displaced proximal humerus fracture further investigated with a CT scan before treatment decision. We selected all patients with a minimum age of 65 years. The included fractures were retrospectively classified according to Neer, and Control Volume severity grade. The included patients were evaluated with Simple Shoulder Test (SST). A statistical analysis was performed to correlate the type of treatment and the clinical results to the Neer classification and the Control Volume severity grade.

Results

Sixty-four patients (80%), were available for the telephonically interview at a mean follow up of 4 years and were included. According to the Control Volume model, we identified fracture with a low, medium and high severity grade, in 23 (36%), 13 (20%), and, 28 (44%) cases, respectively. Fifteen patients (23,5%) were conservatively treated, whether fourty-nine patients (76,5%) were operated. We find a statistical correlation between control volume severity grade and type of treatment. No Therapeutic correlation was detected for the Neer classification. A statistical correlation between the severity grade and clinical outcome could be observed only for patients with the same type of treatment.

Conclusions

The use of Control Volume severity grade is associated with better therapeutic and prognostic informations in confront to the Neer classification.

Management of displaced humeral surgical neck fractures in daily clinical practice: hanging does not re-align the fracture

INTRODUCTION

It is unclear if the collar and cuff treatment improve alignment in displaced surgical neck fractures of the proximal humerus. Therefore, this study evaluated if the neckshaft angle and extent of displacement would improve between trauma and onset of radiographically visible callus in non-operatively treated surgical neck fractures (Boileau type A, B, C).

MATERIALS AND METHODS

A consecutive series of patients (≥ 18 years old) were retrospectively evaluated from a level 1 trauma center in Australia (inclusion period: 2016-2020) and a level 2 trauma center in the Netherlands (inclusion period: 2004 to 2018). Patients were included if they sustained a Boileau-type fracture and underwent initial non-operative treatment. The first radiograph had to be obtained within 24 h after the initial injury and the follow-up radiograph(s) 1 week after trauma and before the start of radiographically visible callus. On each radiograph, the maximal medial gap (MMG), maximal lateral gap (MLG), and neck-shaft angle (NSA) were measured. Linear mixed modelling was performed to evaluate if these measurements would improve over time.

RESULTS

Sixty-seven patients were included: 25 type A, 11 type B, and 31 type C fractures. The mean age (range) was 68 years (24-93), and the mean number (range) of follow-up radiographs per patient was 1 (1-4). Linear mixed modelling on both MMG and MLG revealed no improvement during follow-up among the three groups. Mean NSA of type A fractures improved significantly from 161° at trauma to 152° at last follow-up (p-value = 0.004).

CONCLUSIONS

Apart from humeral head angulation improvement in type A, there is no increase nor reduction in displacement among the three fracture patterns. Therefore, it is advised that surgical decision-making should be performed immediately after trauma.

LEVEL OF CLINICAL EVIDENCE

Level IV, retrospective case series.

Three-dimensional printing models increase inter-rater agreement for classification and treatment of proximal humerus fractures

BACKGROUND

Proximal humerus fractures (PHF) are frequent, however, several studies show low inter-rater agreement in the diagnosis and treatment of these injuries. Differences are usually related to the experience of the evaluators and/or the diagnostic methods used. This study was designed to investigate the hypothesis that shoulder surgeons and diagnostic imaging specialists using 3D printing models and shoulder CT scans in assessing proximal humerus fractures.

METHODS

We obtained 75 tomographic exams of PHF to print three-dimensional models. After, two shoulder surgeons and two specialists in musculoskeletal imaging diagnostics analyzed CT scans and 3D models according to the Neer and AO/OTA group classification and suggested a treatment recommendation for each fracture based on the two diagnostic methods.

RESULTS

The classification agreement for PHF using 3D printing models among the 4 specialists was moderate (global k = 0.470 and 0.544, respectively for AO/OTA and Neer classification) and higher than the CT classification agreement (global k = 0.436 and 0.464, respectively for AO/OTA and Neer). The inter-rater agreement between the two shoulder surgeons were substantial. For the AO/OTA classification, the inter-rater agreement using 3D printing models was higher (k = 0.700) than observed for CT (k = 0.631). For Neer classification,  inter-rater agreement with 3D models was similarly higher (k = 0.784) than CT images (k = 0.620). On the other hand, the inter-rater agreement between the two specialists in diagnostic imaging was moderate. In the AO/OTA classification, the agreement using CT was higher (k = 0.532) than using 3D printing models (k = 0.443), while for Neer classification, the agreement was similar for both 3D models (k = 0.478) and CT images (k = 0.421). Finally, the inter-rater agreement in the treatment of PHF by the 2 surgeons was higher for both classifications using 3D printing models (AO/OTA-k = 0.818 for 3D models and k = 0.537 for CT images). For Neer classification, we saw k = 0.727 for 3D printing models and k = 0.651 for CT images.

CONCLUSION

The insights from this diagnostic pilot study imply that for shoulder surgeons, 3D printing models improved the diagnostic agreement, especially the treatment indication for PHF compared to CT for both AO/OTA and Neer classifications On the other hand, for specialists in diagnostic imaging, the use of 3D printing models was similar to CT scans for diagnostic agreement using both classifications.

TRIAL REGISTRATION

Brazil Platform under no. CAAE 12273519.7.0000.5505.

Three-dimensional models increase the interobserver agreement for the treatment of proximal humerus fractures

Background

The agreement for the treatment of proximal humerus fractures is low. Interpretation of exams used for diagnosis can be directly associated with this limitation. This study proposes to compare the agreement between experts and residents in orthopedics for treatment indication of proximal humerus fractures, utilizing 3D-models, holography (augmented reality), x-rays, and tomography as diagnostic methods.

Methods

Twenty orthopedists (ten experts in shoulder and elbow surgery and ten experts in traumatology) and thirty resident physicians in orthopedics evaluated nine fractures of the proximal humerus, randomly distributed as x-rays, tomography, 3D-models and holography, using the Neer and AO / OTA Classifications. After, we evaluated the interobserver agreement between treatment options (conservative, osteosynthesis and arthroplasty) and whether the experience of the evaluators interfered with the results.

Results

The interobserver agreement analysis showed the following kappa-values: κ = 0.362 and κ = 0.306 for experts and residents (3D-models); κ = 0.240 and κ = 0.221 (X-ray); κ = 0.233 and κ = 0.123 (Tomography) and κ = 0.321 and κ = 0.160 (Holography), for experts and residents respectively. Moreover, residents and specialists were discordant in the treatment indication using Tomography as a diagnostic method (p = 0.003). The same was not seen for the other diagnostic methods (p > 0.05).

Conclusions

Three-dimensional models showed, overall, the highest interobserver agreement (experts versus residents in orthopedics) for the choice of treatment of proximal humerus fractures compared to X-ray, Tomography, and Holography. Agreement in the choice of treatment among experts that used Tomography and Holography as diagnostic methods were two times higher compared to residents.

Trial registration

Registered in Brazil Platform under no. CAAE 12273519.7.0000.5505.