Midterm outcome and complications after minimally invasive treatment of displaced proximal humeral fractures in patients younger than 70 years using the Humerusblock

Morphology and novel classification of proximal humeral fractures

Background: The morphology of proximal humeral fractures (PHFs) is complex, and the fixation and selection of implants need to be guided by the fracture type and classification, which requires an accurate understanding of the fracture line. This study had three purposes. 1) Define and analyze the fracture lines and morphological features of all types PHFs by three-dimensional (3D) mapping technology. 2) Determine the osteotomy position of the biomechanical model of the PHFs according to the fracture heat map. 3) Based on the analysis of the pathological morphology and distribution of a large number of consecutive cases of PHFs, propose a novel classification of PHFs. Methods: We retrospectively collected 220 cases of PHFs and generated a 3D fracture map and heat map based on computed tomography (CT) imaging. Through analysis of the fracture morphology of the 220 PHFs, a novel classification was proposed. The primary criterion for staging was the continuity between the humeral head and the greater tuberosity and lesser tuberosity, and the secondary criterion was the relationship between the humeral head segment and the humeral shaft. Results: The fracture line was primarily found around the metaphyseal zone of region of the surgical neck, with the most extensive distribution being below the larger tuberosity and on the posterior medial side of the epiphysis. We suggest that the osteotomy gap should be immediately (approximately 5-10 mm) below the lower edge of the articular surface. The most common type of fracture was type I3 (33 cases, 15.0%), followed by type IV3 fracture (23 cases, 10.4%), and type III2 fracture (22 cases, 10.0%). Interobserver and intraobserver reliability analysis for the fracture classification revealed a k value (95% confidence interval) of 0.639 (0.57-0.71) and 0.841, P < 0.01, respectively. Conclusion: In this study, the fracture line and morphological characteristics of PHFs were clarified in detail by 3D mapping technique. In addition, a new classification method was proposed by analysis of the morphological characteristics of 220 PHFs, A two-part fracture model for PHFs is also proposed.

Effect of humeral rotation on the reliability of radiographic measurements for proximal humerus fractures

BACKGROUND

There are concerns as to the reliability of proximal humerus radiographic measurements, particularly regarding the rotational position of the humerus when obtaining radiographs.

METHODS

Twenty-four patients with proximal humerus fractures fixed surgically with locked plates received postoperative anteroposterior radiographs with the humerus in neutral rotation and in 30° of internal and external rotation. Radiographic measurements for head shaft angle, humeral offset and humeral head height were performed in each humeral rotation position. Intra-class correlation coefficient was used to assess inter-rater and intra-rater reliability. Mean differences (md) in measurements between humeral positions was evaluated using one-way ANOVA.

RESULTS

Head shaft angle demonstrated good-to-excellent reliability; the highest estimates for inter-rater reliability (ICC: 0.85; 95% CI: 0.76, 0.94) and intra-rater reliability (ICC: 0.96; 95% CI: 0.93, 0.98) were achieved in neutral rotation. There were significant differences in measurement values between each rotational position, with mean head shaft angle of 133.1° in external rotation, and increasingly valgus measurements in neutral (md: 7.6°; 95% CI: 5.0, 10.3°; p < 0.001) and internal rotation (md: 26.4°; 95% CI: 21.8, 30.9°; p < 0.001). Humeral head height and humeral offset showed good-to-excellent reliability in neutral and external rotation, but poor inter-rater reliability in internal rotation. Humeral head height was significantly greater using internal compared to external rotation (md: 4.5 mm; 95% CI: 1.7, 7.3 mm; p = 0.002). Humeral offset was significantly greater in external compared to internal rotation (md: 4.6 mm; 95% CI: 2.6, 6.6 mm; p < 0.001).

CONCLUSIONS

Views of the humerus in neutral rotation and 30° of external rotation displayed superior reliability. Differences in radiographic measurement values, depending on humeral rotation views, can make for problematic correlations with patient outcome measures. Studies assessing radiographic outcomes following proximal humerus fractures should ensure standardized humeral rotation for obtaining anteroposterior shoulder radiographs, with neutral rotation and external rotation views likely yielding the most reliable results.

LEVEL OF EVIDENCE

Level IV.

[Fracture analysis, indication for endoprosthesis and implant selection in proximal humeral fractures]

Proximal humeral fractures (PHF) are the third most common fracture in humans and the incidence is increasing. There are basically three treatment strategies: conservative, joint-preserving reconstructive or joint-replacing procedures. In addition to fracture morphology, patient-specific and surgeon-specific factors are particularly important when deciding on treatment. The experience and training of the surgeon also play a decisive role. In the case of joint-preserving treatment, the risk of osteosynthesis failure and of sequelae of the fracture must always be assessed. If conservative or reconstructive treatment methods are not promising, the joint-replacing procedure is the treatment of choice. The anatomical fracture prosthesis is only indicated, if at all, for young patients with a destroyed humeral head with a preserved rotator cuff and large fragments of the tuberosities. In advanced age, the implantation of a reverse endoprosthesis is increasingly used for dislocated, multifragmentary PHF. In both procedures, the anatomical healing of the tuberosities has a significant impact on the functional outcome.

Comparison of Locked Plating of Varus Displaced Proximal Humeral Fractures With and Without Fibula Allograft Augmentation

OBJECTIVE

To compare the clinical and radiographic outcomes between patients treated with fibula allograft-augmented locking compression fixation and patients treated with locking compression fixation alone for 2- and 3-part proximal humeral fractures with varus displacement.

DESIGN

Retrospective review.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

One hundred two patients treated with locking plate fixation ± fibular allograft augmentation confirmed intraoperatively by visual inspection to have varus-angulated, 2- and 3-part proximal humerus fractures with at least 45 degrees of varus angulation at the neck/shaft and at least 1 cm of displacement.

INTERVENTION

Proximal humerus locking plate (PHILOS; Synthes, Paoli, PA) with or without fibula allograft augmentation.

MAIN OUTCOME MEASUREMENTS

Statistical analysis to determine the differences between fractures treated with locking compression fixation ± fibula allograft augmentation regarding complications, shoulder reported outcome measures, and patient ROMs (Visual Analog Score (VAS), Disabilities of the Arm, Shoulder and Hand, and Simple Shoulder Test scores). Medical comorbidities as potential risk factors for complication from surgery were also evaluated.

RESULTS

Of 102 surgical cases, 27 were augmented with fibula allograft and 75 were not. Postoperatively, there were 16 noncatastrophic varus collapses of the fracture, 6 catastrophic varus collapses, and 5 deaths. Addition of fibula allograft did not significantly affect postoperative varus collapse, shoulder ROM, pain, or PROMs.

CONCLUSION

Addition of fibula allograft to patients sustaining varus-angulated, 2- and 3-part proximal humeral fractures conferred no benefit to patient outcomes at our institution.

LEVEL OF EVIDENCE

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

Clinical and Radiographic Outcomes After Surgical Treatment of Proximal Humeral Fractures with Head-Split Component

BACKGROUND

Head-split fractures are a subgroup of proximal humeral fractures in which the fracture line affects the articular surface. Limited data are available regarding outcomes and risk factors for failure following surgical treatment of this rare fracture type.

METHODS

Of 45 patients with head-split fractures identified, a total of 30 (67%) were included in this retrospective study, with a mean follow-up of 49 ± 18 months (range, 12 to 83 months). Of those 30, 24 were treated with open reduction and internal fixation (ORIF), 4 with reverse total shoulder arthroplasty (RTSA), and 2 with hemiarthroplasty. Subjective Shoulder Value, Simple Shoulder Test, Constant score, and biplanar radiographs were assessed. Fracture pattern, quality of reduction, eventual complications, revision procedures, and clinical failure (adjusted Constant score < 40) were analyzed, and risk factors for failure were calculated.

RESULTS

The overall complication rate was 83% (ORIF: 21 of 24 [88%]; RTSA: 3 of 4 [75%]; and hemiarthroplasty: 1 of 2 [50%]). The most common complications following ORIF were humeral head osteonecrosis (42%), malunion of the lesser tuberosity (33%), and screw protrusion (29%), whereas all complications following RTSA were related to tuberosity problems. Revision was performed in 7 of 24 (29%) of initial ORIF patients, and no revisions were performed in RTSA or hemiarthroplasty patients. Four patients (17%) who underwent primary ORIF underwent conversion to RTSA, and 3 patients (12.5%) had screw removal due to penetration. The overall clinical failure rate was 50% (ORIF: 12 of 24 [50%]; RTSA: 1 of 4 [25%]; and hemiarthroplasty: 2 of 2 [100%]). No significant association was found between preoperative factors and clinical failure. ORIF and primary RTSA showed higher average clinical outcome scores than primary hemiarthroplasty and secondary RTSA. In general, patients who required revision had worse Subjective Shoulder Value (p = 0.014), Simple Shoulder Test (p = 0.028), and adjusted Constant scores (p = 0.069).

CONCLUSIONS

Head-split fractures of the humerus treated with ORIF showed high complication and revision rates. RTSA resulted in comparable clinical outcomes and complication rates; however, the complications associated with RTSA were mostly related to tuberosity problems, which in this small series did not require revision. Therefore, RTSA may be the most predictable treatment option for head-split fractures in elderly patients.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete list of levels of evidence.

Classification of proximal humeral fractures based on a pathomorphologic analysis

BACKGROUND

The purpose of this study was to analyze the pathomorphology of proximal humeral fractures to determine relevant and reliable parameters for fracture classification.

METHODS

A total of 100 consecutive acute proximal humeral fractures in adult patients were analyzed by 2 non-independent observers from a single shoulder department using a standardized protocol based on biplane radiographs and 3-dimensional computed tomography scans. A fracture classification system based on the most reliable key features of the pathomorphologic analysis was created, and its reliability was tested by 6 independent shoulder experts analyzing another 100 consecutive proximal humeral fractures.

RESULTS

The head position in relation to the shaft (varus, valgus, sagittal deformity) and the presence of tuberosity fractures showed a higher interobserver reliability (κ > 0.8) than measurements for medial hinge, shaft, and tuberosity displacement, metaphyseal extension, fracture impaction, as well as head-split component identification (κ < 0.7). These findings were used to classify nondisplaced proximal humeral fractures as type 1, fractures with normal coronal head position but sagittal deformity as type 2, valgus fractures as type 3, varus fractures as type 4, and fracture dislocations as type 5. The fracture type was further combined with the fractured main fragments (G for greater tuberosity, L for lesser). Interobserver and intraobserver reliability analysis for the fracture classification revealed a κ value (95% confidence interval) of 0.700 (0.631-0.767) and 0.917 (0.879-0.943), respectively.

CONCLUSION

The new classification system with emphasis on the qualitative aspects of proximal humeral fractures showed high reliability when based on a standardized imaging protocol including computed tomography scans.