Arthur Lignel1, Julien Berhouet2, Marc-Alexandre Loirat3, Philippe Collin4, Hervé Thomazeau3, David Gallinet5, Pascal Boileau6, Luc Favard5. 1. CHU Pontchaillou, 35000 Rennes, France. Electronic address: arthur.lignel@chu-rennes.fr. 2. CHU de Tours, 37000 Tours, France. 3. CHU Pontchaillou, 35000 Rennes, France. 4. CHP de Saint-Grégoire, 35760 Saint-Grégoire, France. 5. Upper Limb Orthopedic Surgery University, 25000 Besançon, France. 6. CHU de Nice, 06000 Nice, France.
Abstract
INTRODUCTION: Reverse shoulder arthroplasty (RSA) is a key tool in the orthopedic trauma surgeon's arsenal, especially when faced with a proximal humerus fracture in older patients. However, few studies have focused on the glenoid side of RSA in this indication as the implant is placed in a generally healthy scapula. HYPOTHESIS: Glenoid implants for RSA after trauma are well positioned and do not often cause complications. MATERIAL AND METHODS: Retrospective multicenter study of 513 patients who underwent RSA because of a proximal humerus fracture. The mean follow-up was 55 months. Radiographs were used to assess the height and tilt of the glenoid implant, along with the development of scapular notching or loosening. The clinical outcomes were determined based on the Constant score. RESULTS: At the last follow-up, 44% of shoulders had scapular notching, 7% of which were severe (stages 3-4). This notching was progressive, with two resulting in loosening. The rate of severe notching was higher in patients with a high glenoid implant (62.5% vs. 42.3%, p=0.03) or glenosphere with superior tilt (58.3% vs. 37.8%, p=0.02). Nine patients had confirmed loosening and 63 had potential loosening. This was more common in cases with superior tilt (9.3% vs. 0.4%, p<0.001). Patients with a high glenoid implant had a lower Constant score (57 vs. 45, p<0.001). There fewer cases of severe notching when a lateralized glenoid implant was used (0% vs. 7%, p<0.05) and/or the humeral implant had a smaller neck-shaft angle (implants<155°: 3% vs. implants at 155°: 8.5%, p=0.03). DISCUSSION AND CONCLUSION: Glenoid loosening and severe scapular notching are related to poor positioning and/or incorrect orientation of the glenosphere. Implant selection is important, as there is little to no notching when less-angled humeral implants and lateralized glenoid implants are used. LEVEL OF EVIDENCE: IV.
INTRODUCTION: Reverse shoulder arthroplasty (RSA) is a key tool in the orthopedic trauma surgeon's arsenal, especially when faced with a proximal humerus fracture in older patients. However, few studies have focused on the glenoid side of RSA in this indication as the implant is placed in a generally healthy scapula. HYPOTHESIS: Glenoid implants for RSA after trauma are well positioned and do not often cause complications. MATERIAL AND METHODS: Retrospective multicenter study of 513 patients who underwent RSA because of a proximal humerus fracture. The mean follow-up was 55 months. Radiographs were used to assess the height and tilt of the glenoid implant, along with the development of scapular notching or loosening. The clinical outcomes were determined based on the Constant score. RESULTS: At the last follow-up, 44% of shoulders had scapular notching, 7% of which were severe (stages 3-4). This notching was progressive, with two resulting in loosening. The rate of severe notching was higher in patients with a high glenoid implant (62.5% vs. 42.3%, p=0.03) or glenosphere with superior tilt (58.3% vs. 37.8%, p=0.02). Nine patients had confirmed loosening and 63 had potential loosening. This was more common in cases with superior tilt (9.3% vs. 0.4%, p<0.001). Patients with a high glenoid implant had a lower Constant score (57 vs. 45, p<0.001). There fewer cases of severe notching when a lateralized glenoid implant was used (0% vs. 7%, p<0.05) and/or the humeral implant had a smaller neck-shaft angle (implants<155°: 3% vs. implants at 155°: 8.5%, p=0.03). DISCUSSION AND CONCLUSION: Glenoid loosening and severe scapular notching are related to poor positioning and/or incorrect orientation of the glenosphere. Implant selection is important, as there is little to no notching when less-angled humeral implants and lateralized glenoid implants are used. LEVEL OF EVIDENCE: IV.