No Contribution of Tension-Reducing Rotator Cuff Sutures on Locking Plate Fixation in a 2-Part Proximal Humerus Fracture Model

Risk factors and complications in surgical management of proximal humeral fractures: a retrospective analysis of 132 cases

Proximal humeral fractures (PHF), ranking as the third most common osteoporotic fractures, pose a significant challenge in management. With a rising incidence in an aging population, controversy surrounds surgical versus nonoperative treatments, particularly for displaced 3- and 4-part fractures in older patients. Locking plates (LP) and proximal intramedullary nails (PHN) are primary choices for surgical intervention, but both methods entail complications. This retrospective study of 132 patients undergoing surgery for PHF (LP or PHN) aims to identify risk factors for postoperative complications. Results reveal a 31% complication rate, including secondary loss of reduction (17%) and intra-articular screw penetration (13%). Alcohol abuse emerges as the sole patient characteristic linked to complications. Non-anatomical surgical reduction, calcar comminution, and humeral shaft displacement over 10 mm also contribute to increased risks. LP and PHN show comparable complication rates, aligning with existing literature. The study underscores the pivotal role of achieving anatomical surgical reduction in minimizing complications. Surgical technique, fracture pattern, and patient characteristics significantly influence outcomes. Notably, alcohol abuse surfaces as a critical risk factor. The findings emphasize the importance of a nuanced approach to PHF management, tailoring interventions based on fracture characteristics and patient factors. Future research should explore these aspects, particularly in younger patient populations, to enrich our understanding of surgical outcomes in diverse age groups.

Complications of Locked Plating for Proximal Humeral Fractures in Active Patients in a Level One Trauma Center

Background

The incidence of complications associated with locked plating of proximal humerus fractures (PHF) has been reported in up to 40% of surgeries. This study aimed to analyze the incidence and risk factors of complications and re-intervention associated with locked plating of PHF in a an young active working population.

Methods

This retrospective cohort study included patients indicated for locked plating of displaced PHF at a dedicated workers' accident trauma center. The variables analyzed were patient comorbidities, fracture characteristics, and immediate radiologic surgical outcomes. Postoperative complications and risk factors were determined.

Results

A total of 127 patients with a median follow-up of 31 months and a median age of 52 years were included. The complication and reintervention rates were 13.4% and 12.6%, respectively. The main cause of reintervention was post-traumatic stiffness. The incidence of other complications was 4% screw protrusion, 1.6% avascular necrosis, 1.6% varus collapse. Complications were not associated with age, comorbidity, fracture classification, bone mineral density, Hertel's risk factors, presence of calcar comminution, reduction quality, and calcar screw position.

Discussion

The incidence of complications and reintervention was low. The main cause of reintervention was persistent stiffness, and no risk factors for complications were found in this study.

Suture Augmentation Neutralizes Deforming Muscular Forces in a Simulated 2-Part Osteoporotic Proximal Humeral Fracture Model

OBJECTIVES

To evaluate the contribution that tension-relieving sutures, placed between a proximal humeral locking plate and the rotator cuff muscles, had on preventing varus malalignment in an osteoporotic 2-part proximal humerus fracture model.

METHODS

A 2-part fracture model was created in 8 cadaveric specimens and then fixed with a lateral locking plate. A custom shoulder testing system was used to increase loading through the supraspinatus (SS) tendon to drive varus deformity. Trials were performed with no suture placement; SS only; SS and subscapularis (SB); and SS, SB, and infraspinatus. The primary outcome was contribution of each point of suture fixation to prevention of varus collapse.

RESULTS

Suture augmentation to the SS, SB, and infraspinatus significantly decreased humeral head varus collapse when compared with the plate alone at nearly all loads ( P < 0.05). There were no significant differences in humeral head varus collapse between the 3 suture constructs.

CONCLUSIONS

In our biomechanical evaluation of a simulated osteoporotic 2-part proximal humerus fracture with incompetent medial calcar, tension-relieving sutures placed between a lateral locked plate and the rotator cuff tendons prevented varus malalignment.

Muscular Forces Responsible for Proximal Humeral Deformity After Fracture

OBJECTIVES

To evaluate the contribution of each of the rotator cuff muscles and deltoid to fracture deformity in a 2-part proximal humerus fracture model. Our hypothesis was that superior cuff muscles would have the greatest contribution to coronal plane deformity, whereas muscles with anterior and posterior attachments would have the greatest contribution to axial and sagittal plane deformity.

METHODS

A medial wedge osteotomy was created in 8 cadaveric shoulder specimens. A custom shoulder testing system was used to load each rotator cuff muscle and deltoid under increasing loading conditions. Fracture displacement was measured using a Microscribe digitizing system. The primary outcome was the contribution of each muscle to varus collapse. Secondary outcomes included contributions of each muscle to apex anterior/posterior deformity and humeral head anteversion/retroversion.

RESULTS

Unbalanced loading of the supraspinatus resulted in the greatest varus deformity (34.5 ± 2.3 degrees), followed by the infraspinatus (22.3 ± 3.6 degrees) and subscapularis (21.7 ± 3.1 degree) (P < 0.05). Unbalanced loading of the subscapularis induced the greatest apex posterior (27.5 ± 4.8 degrees, P < 0.05) and retroversion (39.0 ± 5.6 degrees, P < 0.05) deformity, whereas the infraspinatus induced the greatest apex anterior (8.7 ± 3.4 degrees, P > 0.05) and anteversion (17.7 ± 5.7 degrees, P > 0.05) deformity.

CONCLUSIONS

In this proximal humerus fracture model, the supraspinatus was the primary driver of varus deformity, whereas the subscapularis and infraspinatus contributed to apex posterior/retroversion and apex anterior/anteversion, respectively. The subscapularis and infraspinatus are also important secondary drivers of varus deformity. This study establishes a physiologically relevant fracture model that mimics in vivo conditions for future biomechanical testing.

Principles of Locking Plate Fixation of Proximal Humerus Fractures

Proximal humerus fractures are common, particularly in elderly patients and those with osteopenia or osteoporosis. Although nonsurgical management results in satisfactory outcomes for most patients, surgical treatment is indicated in select cases. Despite an increasing trend toward arthroplasty, open reduction and internal fixation of proximal humerus fractures can still provide excellent clinical outcomes. Proper technique for internal fixation of the proximal humerus requires an understanding of osseous and neurovascular anatomy. In particular, understanding reliable regions of biomechanically superior bone can help prevent failure of fixation. Biomechanical studies have shown that locked plating of proximal humerus fractures provides stable fixation. Cadaveric and finite element models underscore the importance of screw placement in the posteromedial metaphysis. When medial column support is challenging to obtain, or when bone quality is poor, augmentation with bone autograft, allograft, and/or synthetic composites can improve the biomechanics of internal fixation constructs. The purpose of this review is to outline the anatomic, biologic, and biomechanical principles of plate fixation for proximal humerus fractures to provide evidence-based recommendations for optimizing fixation and preventing fixation failure.

PHILOS Plate Plus Oblique Insertion of Autologous Fibula for 2-Part Proximal Humerus Fractures With Medial Column Disruption: A Retrospective Study

Introduction:

The aim of this retrospective study was to evaluate the outcomes of older patients with 2-part proximal humerus fractures (PHFs) with medial column disruption stabilized using a proximal humeral internal locking system (PHILOS) plate plus oblique insertion of autologous fibula as a primary procedure.

Materials and Methods:

Data involving 112 patients (112 shoulders) sustaining 2-part PHFs with medial column disruption treated with PHILOS plate plus oblique insertion of autologous fibula as a primary procedure during 2012-2019 were identified. The median follow-up was 36 months (range: 11.2-43.5 months). The primary endpoint was the Constant scores and American Shoulder and Elbow Surgeons (ASES) scores. The secondary endpoint was the main orthopedic complication rate.

Results:

The median Constant and ASES scores were 78 (range, 52-95) and 77 (range, 62-96) at the final follow-up, respectively. The main orthopedic complication rate was 10.7% (12/112). Twelve orthopedic complications in 8 patients were detected, and they involved loss of reduction, varus collapse, aseptic loosening, mal-union, revision, and intolerable shoulder pain. Of these complications, 3 (2.6%) involved loss of reduction, 2 (1.7%) involved varus collapse, 3 (2.6%) involved aseptic loosening, 1 (0.8%) involved mal-union, 2 (1.7%) required revision surgery, and 1 (0.8%) presented intolerable shoulder pain.

Conclusion:

PHILOS plate plus oblique insertion of autologous fibula as a primary procedure may yield good functional outcomes and a low rate of the main orthopedic complications.

Surgical Considerations in the Treatment of Osteoporotic Proximal Humerus Fractures

Proximal humerus fractures in the setting of osteoporosis can be technically challenging. Intraoperative challenges include comminution, thin cortical bone, and crushed cancellous bone that lead to difficulties in obtaining and maintaining a reduction and hardware fixation. Loss of fixation and varus collapse continue to be problems despite the utilization of modern locking plate fixation. A clearer understanding of predictors of fixation failure and the encouraging early results of reverse total shoulder arthroplasty (RTSA) have resulted in increased utilization of RTSA for the primary treatment of proximal humerus fractures.

Biomechanical analysis of plate systems for proximal humerus fractures: a systematic literature review

BACKGROUND

Proximal humerus fractures are the third most common in the human body but their management remains controversial. Open reduction and internal fixation with plates is one of the leading modes of operative treatment for these fractures. The development of technologies and techniques for these plates, during the recent decades, promise a bright future for their clinical use. A comprehensive review of in vitro biomechanical studies is needed for the comparison of plates' mechanical performance and the testing methodologies. This will not only guide clinicians with plate selection but also with the design of future in vitro biomechanical studies. This review was aimed to systematically categorise and review the in vitro biomechanical studies of these plates based on their protocols and discuss their results. The technologies and techniques investigated in these studies were categorised and compared to reach a census where possible.

METHODS AND RESULTS

Web of Science and Scopus database search yielded 62 studies. Out of these, 51 performed axial loading, torsion, bending and/or combined bending and axial loading while 11 simulated complex glenohumeral movements by using tendons. Loading conditions and set-up, failure criteria and performance parameters, as well as results for each study, were reviewed. Only two studies tested four-part fracture model while the rest investigated two- and three-part fractures. In ten studies, synthetic humeri were tested instead of cadaveric ones. In addition to load-displacement data, three-dimensional motion analysis systems, digital image correlation and acoustic emission testing have been used for measurement.

CONCLUSIONS

Overall, PHILOS was the most tested plate and locking plates demonstrated better mechanical performance than non-locking ones. Conflicting results have been published for their comparison with non-locking blade plates and polyaxial locking screws. Augmentation with cement [calcium phosphate or poly(methyl methacrylate)] or allografts (fibular and femoral head) was found to improve bone-plate constructs' mechanical performance. Controversy still lies over the use of rigid and semi-rigid implants and the insertion of inferomedial screws for calcar region support. This review will guide the design of in vitro and in silico biomechanical tests and also supplement the study of clinical literature.

Complications of locked plating for proximal humeral fractures-are we getting any better?

BACKGROUND

Complication rates reported after locking plate fixation of proximal humeral fractures still range up to 40%. Whether modifications of surgical techniques, use of primary shoulder arthroplasty, or a fracture-specific management resulted in decreased complication rates during recent years remains unclear. Therefore, the aim of this long-term observation study was to analyze the incidence of complications and revision surgery after locked plating.

METHODS

Between February 2002 and December 2013, 788 patients (aged 67.4 ± 17.3 years) with displaced proximal humeral fractures were treated with locking plate, primary hemiarthroplasty (HA), or reverse shoulder arthroplasty (RSA). Standardized follow-up included radiographs at 1 day, 6 weeks, and 3, 6, and 12 months. Complications and unplanned revision surgery were prospectively recorded over the complete follow-up.

RESULTS

Of 788 patients, 646 (82%) were treated with locking plate, 82 (10.4%) with HA, and 60 (7.6%) with RSA. Mean follow-up was 14.8 ± 3.8 months. The mean complication rate associated with locked plating was 12.8%, and revision surgery was necessary in 11.6%. Within the last 5 years, the loss of fixation rate markedly decreased from 14.3% to 4.8%; simultaneously, an increased use of RSA was observed.

CONCLUSION

The overall complication rate of locking plate osteosynthesis for proximal humeral fractures has been decreasing considerably within the last years. Among others, this might be due to an increased use of primary RSA for complex fracture types. In addition to a precise surgical technique, choosing the adequate treatment for each individual fracture to avoid complications and revision surgery is of utmost importance.

Biomechanical Contribution of Tension-Reducing Rotator Cuff Sutures in 3-Part Proximal Humerus Fractures

OBJECTIVES

Using a cadaveric 3-part fracture model and cyclic loading protocol, our study objectives were to quantify the stabilizing effect of tension-reducing rotator cuff sutures in terms of fracture displacement across the surgical neck and greater tuberosity compared with a control group in which no sutures were used.

METHODS

Six matched pairs of fresh frozen specimens underwent a standardized, 3-part, proximal humerus fracture and were split into 2 groups. The control group had the fracture fixed with a plate and screw construct only while the experimental group had additional suture fixation through the plate to each rotator cuff tendon. Active abduction through the rotator cuff was simulated for 100, 200, 300, and 400 cycles and to failure at 1000 N. A Mann-Whitney U test compared cyclic displacement of the greater tuberosity and surgical neck fracture gaps and load to failure between the 2 groups.

RESULTS

There was no significant difference (P > 0.05) in fracture gap between fixation methods at the surgical neck at 100 (P = 0.13), 200 (P = 0.07), 300 (P = 0.49), and 400 (P = 0.07) cycles. There was no significant difference (P > 0.05) between fixation methods in the fracture gap at the greater tuberosity at 100 (P = 0.39), 200 (P = 1.00), 300 (P = 0.31), and 400 (P = 0.59) cycles. There was no significant difference (P > 0.5) at 1000 N at the surgical neck (P = 0.70) or the greater tuberosity (P = 0.39).

CONCLUSIONS

Tension-relieving rotator cuff sutures do not add stability to the repair of 3-part proximal humerus fractures. Varus collapse and greater tuberosity displacement are common complications associated with 3-part fractures. No mechanical data exist to demonstrate benefit of adding suture to a plate and screw construct for limiting fracture displacement.