Functional results and unfavorable events after treatment of proximal humerus fractures using a new locking plate system.

BACKGROUND: Proximal humerus fractures are often treated with a fixed-angle titanium plate osteosynthesis. Recently, plates made of alternative materials such as carbon fibre-reinforced polyetheretherketone (CFR-PEEK) have been introduced. This study presents the postoperative results of patients treated with a CFR-PEEK plate. METHODS: Patients with proximal humerus fractures treated with a CFR-PEEK plate (PEEKPower™ Humeral Fracture Plate (HFP)) were included. In follow-up examination, age and gender adjusted Constant-Murley Score (ACS), Subjective Shoulder Value (SSV), Quick Disabilities of the Arm, Shoulder and Hand Score (QDASH) and pain score (Visual Analog Scale (VAS)) were analyzed. General condition at follow-up was measured by European Quality of Life 5 Dimensions 3 Level Version (EQ-5D-3L). Range of motion was recorded. In addition, radiographs at follow-up, unfavorable events and revision rate were analyzed. RESULTS: In total, 98 patients (66.0 ± 13.2 years, 74 females, 24 males) were reexamined. Mean follow-up was 27.6 ± 13.2 months. There were 15 2-part, 28 3-part and 55 4-part fractures. The functional scores showed good results: SSV 83.3 ± 15.6%, QDASH 13.1 ± 17.0 and ACS 80.4 ± 16.0. A 4-part-fracture, head split component, nonanatomic head shaft reposition and preoperative radiological signs of osteoarthritis were significant negative predictors for poorer clinical scores. Unfavourable events were observed in 27 patients (27.6%). Revision surgery was performed in 8 (8.2%) patients. Risk factors for an unfavourable event were female gender, age of 50 years and older, diabetes, affected dominant hand, 4-part fracture, head split and preoperative radiological signs of osteoarthritis. CONCLUSION: There are several advantages of the CFR-PEEK plate (PEEKPower™ Humeral Fracture Plate (HFP)) such as the polyaxial screw placement and higher stability of locking screws. In summary, the CFR-PEEK plate osteosynthesis is a good alternative with comparable clinical results and some biomechanical advantages. Proximal humerus fractures show good clinical results after treatment with a CFR-PEEK plate. The revision rate and the risk of unfavorable events are not increased compared to conventional titanium plate osteosynthesis. LEVEL OF EVIDENCE: IV.

VEGF-D-mediated signaling in tendon cells is involved in degenerative processes.

Vascular endothelial growth factor (VEGF) signaling is crucial for a large variety of cellular processes, not only related to angiogenesis but also in nonvascular cell types. We have previously shown that controlling angiogenesis by reducing VEGF-A signaling positively affects tendon healing. We now hypothesize that VEGF signaling in non-endothelial cells may contribute to tendon pathologies. By immunohistochemistry we show that VEGFR1, VEGFR2, and VEGFR3 are expressed in murine and human tendon cells in vivo. In a rat Achilles tendon defect model we show that VEGFR1, VEGFR3, and VEGF-D expression are increased after injury. On cultured rat tendon cells we show that VEGF-D stimulates cell proliferation in a dose-dependent manner; the specific VEGFR3 inhibitor SAR131675 reduces cell proliferation and cell migration. Furthermore, activation of VEGFR2 and -3 in tendon-derived cells affects the expression of mRNAs encoding extracellular matrix and matrix remodeling proteins. Using explant model systems, we provide evidence, that VEGFR3 inhibition prevents biomechanical deterioration in rat tail tendon fascicles cultured without load and attenuates matrix damage if exposed to dynamic overload in a bioreactor system. Together, these results suggest a strong role of tendon cell VEGF signaling in mediation of degenerative processes. These findings give novel insight into tendon cell biology and may pave the way for novel treatment options for degenerative tendon diseases.

Proximal humeral fracture morphology in patients with advanced cuff tear arthropathy: an observational study in a surgically treated cohort.

BACKGROUND: In the presence of cuff tear arthropathy (CTA), joint kinematics is alternated and fracture configuration might be different. The purpose of this study was to identify fracture patterns in patients with advanced CTA to facilitate recognition and treatment. METHODS: Radiographs and computed tomography scans of all patients undergoing surgical treatment for a proximal humeral fracture (PHF) in our institution during a 5-year period were retrospectively analyzed. Fracture pattern according to the AO-OTA and Resch classification and the presence of CTA were evaluated. Glenoid configuration according to Walch, fatty atrophy of the supraspinatus muscle and the centrum-collum-diaphyseal (CCD) angle were analyzed. RESULTS: A total of 574 out of 713 patients were included. Twenty-three patients (4%) with a mean age of 82 ± 8 years showed advanced CTA with acetabularization of the acromion (≥ stage 3 according to Hamada/Fukuda). There were exclusively valgus fractures with a mean CCD angle of 158° ± 18°. Patients with CTA ≥ grade 3 had a nearly twofold greater risk (risk ratio: 1.8; confidence interval (CI): 95% 1.6-1.9; p < 0.0001) of sustaining a valgus fracture compared to patients without or with CTA < grade 3. The risk for a tuberosity fracture was nearly twofold greater in patients without or with mild CTA (risk ratio: 1.68; confidence interval (CI): 95% 1.17-2.40; p = 0.0046) compared to those with advanced CTA. CONCLUSION: In advanced CTA, a predominantly valgus fracture pattern can be observed. In addition, fractures of the greater tuberosity were significantly less frequent and were rarely displaced. Up to date, no classification system for PHF has been developed in the setting of CTA although it might indicate a different treatment, and therefore, recognition is crucial. However, when present, this changes the fracture pattern and ability to treat the fracture as the rotator cuff can no longer be utilized as a means of reducing the fragments.

Severe Heterotopic Ossification with Proximal Entrapment of the Ulnar Nerve following Primary Anterior Shoulder Dislocation.

Heterotopic ossifications (HO) in the shoulder are rare. The effectiveness of conservative treatment is limited, and therefore, symptomatic cases are usually treated surgically. However, there are no guidelines for the surgical treatment of HO. Herein, we report the case of a 45-year-old man with severe HO and proximal entrapment of the ulnar nerve following primary anterior shoulder dislocation without concomitant injuries (e.g., fracture and rotator cuff tears). Surgical intervention was indicated, including resection of HO and neurolysis of the brachial plexus. Nine months after surgery, the patient presented with restored shoulder function, pain relief, and good patient satisfaction. The case shows that the ulnar nerve can also be impaired due to HO following shoulder dislocation.

Proximal humeral fracture morphology in patients with advanced osteoarthritis: An observational study in a surgically treated cohort.

BACKGROUND: Several factors affect proximal humeral fracture (PHF) morphology. In the presence of glenohumeral osteoarthritis (GOA), the joint kinematics is alternated which might influence fracture configuration. The purpose of this study was to identify fracture patterns in patients with advanced osteoarthritis to facilitate recognition and treatment. METHODS: In this retrospective analysis, and computed tomography (CT) scans of all patients undergoing surgical treatment for a PHF during a 5-year period were analyzed. Fracture pattern according to the AO Foundation/Orthopaedic Trauma Association (AO-OTA) classification and the presence of GOA were evaluated. In addition, critical shoulder angle (CSA), glenoid configuration, and glenoid inclination (GI) were measured. RESULTS: Of the 713 patients, 574 met the inclusion criteria. A total of 166 patients showed radiological signs of GOA (28.9%). Advanced GOA (stage 2 or 3) was identified in 23 patients (4.0%). In this group, the mean age was 77 ± 10 years, mean CSA was 28.8 ± 4.2°, and the mean GI was 19.0 ± 7.8°. All fractures were extra-articular metaphyseal fractures (5 A2, 11 A3, 7 B1.1). Patients with advanced GOA had more than threefold risk (risk ratio 3.2; confidence interval 95% 2.80-3.74; p < 0.0001) for sustaining a metaphyseal fracture. In patients with GOA grade 1 compared to patients with no radiographic signs of GOA, this could not be observed. CONCLUSION: Patients experiencing PHF with radiological signs of advanced GOA have a higher risk of sustaining a metaphyseal fracture compared to individuals with the absence of or mild GOA. To date, no classification system for PHFs takes preexisting osteoarthritis into account, although it might indicate a different treatment and therefore the recognition is crucial.

Tuberosity healing improves functional outcome following primary reverse shoulder arthroplasty for proximal humeral fractures with a 135° prosthesis.

INTRODUCTION: Reverse shoulder arthroplasty (RSA) is a common treatment for proximal humeral fractures (PHFs) in the elderly. This study evaluates the influence of tuberosity healing (TH) on functional outcome following a 135° humeral inclination RSA for PHFs. METHODS: Retrospectively, all patients with an acute PHF treated with a 135° humeral inclination RSA at four centers during a three-year period were followed up. Constant score (CS), TH and glenoid notching were analyzed. RESULTS: Sixty-four of 100 patients (64%) with a mean age of 76 ± 7 years were available for follow-up at 22 ± 8 months. The mean-adjusted CS was 72%. TH of the greater tuberosity (GT) was 77% and resulted in significantly improved forward flexion (128° vs. 92°; p = 0.003), external rotation (33° vs. 17°; p = 0.03) and adjusted CS (78% vs. 54%, p < 0.005). GT healing rate was 86% with neutral, 70% with lateralized and 33% with an inferior eccentric glenosphere. TH of the lesser tuberosity was 79%. There was 8% complication and 3% revision rate; implant survival was 100%. CONCLUSION: RSA with 135° humeral inclination for PHFs leads to good functional outcome, reproducible results and a high rate of TH. The short-term revision rate is low. TH is associated with improved ROM and functional outcome. LEVEL OF EVIDENCE: III.

Global Responses of Il-1ß-Primed 3D Tendon Constructs to Treatment with Pulsed Electromagnetic Fields.

Tendinopathy is accompanied by a cascade of inflammatory events promoting tendon degeneration. Among various cytokines, interleukin-1ß plays a central role in driving catabolic processes, ultimately resulting in the activation of matrix metalloproteinases and a diminished collagen synthesis, both of which promote tendon extracellular matrix degradation. Pulsed electromagnetic field (PEMF) therapy is often used for pain management, osteoarthritis, and delayed wound healing. In vitro PEMF treatment of tendon-derived cells was shown to modulate pro-inflammatory cytokines, potentially limiting their catabolic effects. However, our understanding of the underlying cellular and molecular mechanisms remains limited. We therefore investigated the transcriptome-wide responses of Il-1ß-primed rat Achilles tendon cell-derived 3D tendon-like constructs to high-energy PEMF treatment. RNASeq analysis and gene ontology assignment revealed various biological processes to be affected by PEMF, including extracellular matrix remodeling and negative regulation of apoptosis. Further, we show that members of the cytoprotective Il-6/gp130 family and the Il-1ß decoy receptor Il1r2 are positively regulated upon PEMF exposure. In conclusion, our results provide fundamental mechanistic insight into the cellular and molecular mode of action of PEMF on tendon cells and can help to optimize treatment protocols for the non-invasive therapy of tendinopathies.