[Research progress in treatment of proximal humeral fracture with fibular allograft and locking plate]

Treatment of proximal humeral fractures accompanied by medial calcar fractures using fibular autografts: A retrospective, comparative cohort study

BACKGROUND

Severe proximal humerus comminuted fractures are often accompanied by medial calcar comminuted fractures and loss of medial support, which are important factors that lead to internal fixation failure. The appropriate treatment for proximal humerus comminuted fractures has not been established. Therefore, this study assessed the outcomes of using a fibular autograft with locking plates to treat severe proximal humerus comminuted fractures.

AIM

To investigate the outcomes of using a fibular autograft with locking plates to treat severe proximal humerus comminuted fractures.

METHODS

This retrospective, comparative cohort study included two groups of patients. Group 1 comprised 22 patients and group 2 comprised 25 patients with complete follow-up data. Group 1 was treated with a fibular autograft with open reduction and locking plates to enable internal fixation. Group 2 was treated with open reduction and locking plates to enable internal fixation. The intraoperative blood loss volume from the shoulder wound, operative time, shoulder wound pain, bone fracture healing time, Constant-Murley score of the shoulder joint, preoperative Holden walking function score, Mallet score of the shoulder joint, and humeral neck-shaft angle during surgery of the two groups were compared, and the differences were analysed using an independent sample t-test.

RESULTS

Group 1 had a shorter mean operative time than group 2 (2.25 ± 0.30 h vs 2.76 ± 0.44 h; P = 0.000). Group 1 had a lower shoulder wound pain score on the first day after surgery than group 2 (7.91 ± 1.15 points vs 8.56 ± 1.00 points; P = 0.044). Group 1 had a shorter fracture healing time than group 2 (2.68 ± 0.48 mo vs 3.64 ± 0.64 mo; P = 0.000). Group 1 had higher Constant-Murley scores of the shoulder joint at 3, 6, and 12 mo after surgery than group 2 (76.64 ± 4.02 points vs 72.72 ± 3.02 points, 86.36 ± 3.53 points vs 82.96 ± 3.40 points, and 87.95 ± 2.77 points vs 84.68 ± 2.63 points, respectively; P = 0.000, 0.002, and 0.000, respectively). Group 1 had higher Mallet scores of the shoulder joint at 3, 6, and 12 mo after surgery than group 2 (10.32 ± 0.57 points vs 9.96 ± 0.54 points, 13.36 ± 1.00 points vs 12.60 ± 0.87 points, and 13.91 ± 0.75 points vs 13.36 ± 0.70 points, respectively; P = 0.032, 0.007, and 0.013, respectively).

CONCLUSION

Using locking plates with a fibular autograft can recreate medial support, facilitate fracture healing, and improve shoulder function; therefore, this may be an effective treatment option for severe proximal humerus comminuted fractures.

[Three-dimensional finite element analysis of exo-cortical placement of humeral calcar screw for reconstruction of medial column stability]

Objective

To explore the biomechanical stability of the medial column reconstructed with the exo-cortical placement of humeral calcar screw by three-dimensional finite element analysis.

Methods

A 70-year-old female volunteer was selected for CT scan of the proximal humerus, and a wedge osteotomy was performed 5 mm medially inferior to the humeral head to form a three-dimensional finite element model of a 5 mm defect in the medial cortex. Then, the proximal humeral locking plate (PHILOS) was placed. According to distribution of 2 calcar screws, the study were divided into 3 groups: group A, in which 2 calcar screws were inserted into the lower quadrant of the humeral head in the normal direction for supporting the humeral head; group B, in which 1 calcar screw was inserted outside the cortex below the humeral head, and the other was inserted into the humeral head in the normal direction; group C, in which 2 calcar screws were inserted outside the cortex below the humeral head. The models were loaded with axial, shear, and rotational loadings, and the biomechanical stability of the 3 groups was compared by evaluating the peak von mises stress (PVMS) of the proximal humerus and the internal fixator, proximal humeral displacement, neck-shaft angle changes, and the rotational stability of the proximal humerus. Seven cases of proximal humeral fractures with comminuted medial cortex were retrospectively analyzed between January 2017 and December 2020. Locking proximal humeral plate surgery was performed, and one (5 cases) or two (2 cases) calcar screws were inserted into the inferior cortex of the humeral head during the operation, and the effectiveness was observed.

Results

Under axial and shear force, the PVMS of the proximal humerus in group B and group C was greater than that in group A, the PVMS of the internal fixator in group B and group C was less than that in group A, while the PVMS of the proximal humerus and internal fixator between group B and group C were similar. The displacement of the proximal humerus and the neck-shaft angle change among the 3 groups were similar under axial and shear force, respectively. Under the rotational torque, compared with group A, the rotation angle of humerus in group B and group C increased slightly, and the rotation stability decreased slightly. All the 7 patients were followed up 6-12 months. All the fractures healed, and the healing time was 8-14 weeks, with an average of 10.9 weeks; the neck-shaft angle changes (the difference between the last follow-up and the immediate postoperative neck-shaft angle) was (1.30±0.42)°, and the Constant score of shoulder joint function was 87.4±4.2; there was no complication such as humeral head varus collapse and screw penetrating the articular surface.

Conclusion

For proximal humeral fractures with comminuted medial cortex, exo-cortical placement of 1 or 2 humeral calcar screw of the locking plate outside the inferior cortex of the humeral head can also effectively reconstruct medial column stability, providing an alternative approach for clinical practice.