Is malunion of the greater tuberosity after reverse shoulder arthroplasty in patients with complex proximal humerus fracture associated with worse clinical outcomes? A prospective cohort study.

PURPOSE: To assess patient outcomes following reverse shoulder arthroplasty in patients with complex proximal humerus fracture and the clinical implications of greater tuberosity malunions. METHODS: This prospective study included 56 patients who underwent RSA (DELTA XTEND™, DePuy Synthes, Warsaw, IN, USA) to treat proximal humerus fractures. We used a standardized suture technique to reattach the tuberosities. Demographic, comorbidity, and radiological parameters were collected. Assessments at 2-year follow-up (n = 49) are given as follows: range of motion (ROM), pain level, Constant Murley scores (CS), subjective shoulder value (SSV), and tuberosity healing. RESULTS: Anatomic tuberosity healing was achieved in 31 (55%) patients (group 1), 14 (25%) had a malunion (group 2), and complete migration occurred in 11 (20%) (group 3). No statistically significant differences between groups 1 and 2 were detected: CS (p = 0.53), SSV (p = 0.07), ROM (forward flexion (FF) p = 0.19, internal rotation (IR) p = 0.34, and external rotation (ER) p = 0.76). Group 3 had poorer outcomes (median [IQR]) than group 1: CS (59 [50-71]) vs. 72 [65-78]), FF (120 [100-150]) vs. 150 [125-160] and ER (- 20 [- 20 to 10] vs. 30 [20-45], respectively. Three complications (group 1) occurred: one-stage revision after low-grade infection, haematoma due to early rivaroxaban intake, and open reduction and internal fixation for acromion insufficiency fracture. No patients showed signs of stem or glenoid loosening after 2 years. CONCLUSION: Cases with complete superior migration experienced poorer clinical outcomes than those with anatomic healing. Despite a relatively high malunion rate, the outcomes were not significantly worse in these patients compared to anatomically healed GT cases.

Limited reliability of grading scapular notching according to Nerot-Sirveaux on anteroposterior radiographs.

INTRODUCTION: Incidences of scapular notching (SN) in reverse shoulder arthroplasty (RSA) range between 0% and 96%, and controversy remain as to its relevance for patient outcome. We assessed the reliability of scapular notching (SN) grading based on the Sirveaux classification system using anteroposterior radiographs. MATERIALS AND METHODS: 206 RSA procedures with 5-year postoperative anteroposterior shoulder radiographs were classified independently by seven assessors according to Sirveaux (session 1). After a review meeting, three assessors re-classified the radiographs along with quality criteria (session 2). SN grading by the majority of assessors was taken as the reference. Classification interobserver reliability was analyzed using Kappa statistics. RESULTS: The incidence of SN was estimated at 53% and 37% at the first and second sessions, respectively. Interobserver reliability Kappa coefficients resulting from the first and second sessions were 0.27 and 0.43, respectively. Case selection based on radiographic quality criteria did not improve SN grading reliability in the second session. CONCLUSION: Agreement between individual surgeons was low when grading SN in RSA according to Sirveaux using anteroposterior radiographs. Consensus among several assessors may increase reliability in research settings.

Effect of plane of arm elevation on glenohumeral kinematics: a normative biplane fluoroscopy study.

BACKGROUND: Understanding glenohumeral motion in normal and pathologic states requires the precise measurement of shoulder kinematics. The effect of the plane of arm elevation on glenohumeral translations and rotations remains largely unknown. The purpose of this study was to measure the three-dimensional glenohumeral translations and rotations during arm elevation in healthy subjects. METHODS: Eight male subjects performed scaption and forward flexion, and five subjects (three men and two women) performed abduction, inside a dynamic biplane fluoroscopy system. Bone geometries were extracted from computed tomography images and used to determine the three-dimensional position and orientation of the humerus and scapula in individual frames. Descriptive statistics were determined for glenohumeral joint rotations and translations, and linear regressions were performed to calculate the scapulohumeral rhythm ratio. RESULTS: The scapulohumeral rhythm ratio was 2.0 ± 0.4:1 for abduction, 1.6 ± 0.5:1 for scaption, and 1.1 ± 0.3:1 for forward flexion, with the ratio for forward flexion being significantly lower than that for abduction (p = 0.002). Humeral head excursion was largest in abduction (5.1 ± 1.1 mm) and smallest in scaption (2.4 ± 0.6 mm) (p < 0.001). The direction of translation, as determined by the linear regression slope, was more inferior during abduction (-2.1 ± 1.8 mm/90°) compared with forward flexion (0.1 ± 10.9 mm/90°) (p = 0.024). CONCLUSIONS: Scapulohumeral rhythm significantly decreased as the plane of arm elevation moved in an anterior arc from abduction to forward flexion. The amount of physiologic glenohumeral excursion varied significantly with the plane of elevation, was smallest for scaption, and showed inconsistent patterns across subjects with the exception of consistent inferior translation during abduction.

Factors influencing intra-articular fluid temperature profiles with radiofrequency ablation.

BACKGROUND: Radiofrequency ablation devices are being used increasingly in arthroscopic surgery. However, there are concerns that excessive temperatures may damage the articular cartilage. The purpose of this study was to investigate the temperature profiles that occur within the glenohumeral space with the use of one commercially available radiofrequency ablation probe. METHODS: Ten fresh-frozen human cadaver shoulder specimens were used. Intra-articular temperatures were measured at different time intervals over a two-minute period at a distance of 1, 3, 5, and 10 mm away from the probe. The radiofrequency probe was activated throughout the range of machine power settings, and irrigation fluid flow was varied (no flow, a flow at 60 mm Hg without suction, and a flow at 60 mm Hg with suction). RESULTS: Temperatures deleterious to articular cartilage chondrocytes (i.e., those in excess of 50 degrees C) were seen with an increased duration of application, a decreased distance between the thermometer and the probe, and a decreased irrigation fluid flow rate. The highest recorded irrigation fluid temperature reached >80 degrees C after two minutes in a no-flow setting. The flow rate was found to be the most significant predictor of intra-articular temperature profiles. The various machine power settings had no apparent influence on temperature, meaning that higher probe settings are not necessarily associated with higher temperature profiles. CONCLUSIONS AND CLINICAL RELEVANCE: These results demonstrate the importance of the management of the irrigation fluid flow rate across the joint during arthroscopic procedures that involve radiofrequency ablation. Even short intervals of limited flow could lead to supraphysiological temperature profiles and potentially to cartilage damage.