Treatment of cephalotuberosity fractures in elderly patients treated by reverse shoulder prosthesis: a study of functional results in relation to deltoid tension

Influence of humeral lengthening on clinical outcomes in reverse shoulder arthroplasty

BACKGROUND

Deltoid tensioning secondary to humeral lengthening after reverse shoulder arthroplasty (RSA) is commonly theorized to be crucial to improving range of motion (ROM) but may predispose patients to acromial/scapular spine fractures and neurologic injury. Clinical evidence linking patient outcomes to humeral lengthening is limited. This study assesses the relationship between humeral lengthening and clinical outcomes after RSA.

METHODS

A single institution review of 284 RSAs performed in 265 patients was performed. Humeral lengthening was defined as the difference in the subacromial height preoperatively to postoperatively as measured on Grashey radiographs. The subacromial height was measured as the vertical difference between the most inferolateral aspect of the acromion and the most superior aspect of the greater tuberosity. The relationship between humeral lengthening and clinical outcomes was assessed on a continuous basis. Secondarily, clinical outcomes were assessed using a dichotomous definition of humeral lengthening (≤25 vs. >25mm) based on prior clinical and biomechanical work purporting a correlation with clinical outcomes. Improvement exceeding the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) for ROM and outcome scores after RSA were also compared.

RESULTS

Humeral lengthening demonstrated a nonlinear relationship with postoperative ROM, clinical outcome scores, and shoulder strength and their improvement preoperatively to postoperatively. Furthermore, there were minimal differences in ROM measures, outcome scores, and shoulder strength when stratified using the dichotomous definition of humeral lengthening. No difference in the proportion of patients exceeding the MCID or SCB when stratified by humeral lengthening ≤25 vs. >25mm was found. There was no difference in humeral lengthening in patients with versus without complications.

CONCLUSION

No clear relationship between humeral lengthening and clinical outcomes was identified. The previously purported 25mm threshold for humeral lengthening did not predict improved patient outcomes. Outcomes after RSA are multifactorial; the relationship between humeral lengthening and outcomes is likely confounded by other patient and surgical factors.

LEVEL OF EVIDENCE

IV; Case Series.

Intra- and Inter-rater Reliability of Postoperative Radiographic Analysis of Reverse Shoulder Arthroplasty in 49 Shoulders After Proximal Humerus Fracture

Introduction

The lateralization shoulder angle (LSA), the distalization shoulder angle (DSA) and the new "pentagon" concept are tools used in scheduled shoulder surgery to evaluate the positioning of reverse shoulder arthroplasty (RSA) implants. There is no information on the intra- and inter-rater reliability of these tools in the context of RSA for a proximal humerus fracture. The first hypothesis was the high reliability of the intra- and inter-rater analysis of the LSA and DSA angles. The second hypothesis was the reproductibility of the pentagon based on LSA and DSA analysis.

Methods

Forty-nine patients were evaluated retrospectively with a minimum of 2 years radiological follow-up after RSA surgery. Tuberosity healing was evaluated using an AP radiograph of the shoulder and their location analyzed within the said "pentagon" defined by the LSA/DSA angles and the maximum lengthening recommended.

Results

The intra-rater analysis found strong to an almost perfect agreement for the LSA and DSA. The agreement was moderate to strong for the pentagon. The inter-rater analysis found a fair agreement for the LSA and moderate agreement for the DSA and pentagon.

Conclusion

The LSA/DSA is used in patients undergoing RSA for glenohumeral OA. In this context, the tuberosities were intact and certain complications inherent to RSA for humeral fracture were not present. The population studied here (RSA after fracture) creates an interpretation bias due to the difficulty in analyzing tuberosity position.

Level of Evidence

4, retrospective study.

Does healing of both greater and lesser tuberosities improve functional outcome after reverse shoulder arthroplasty for fracture? A retrospective study of twenty-eight cases with a computed tomography scan at a minimum of one-year follow-up

PURPOSE

Reverse shoulder arthroplasty (RSA) is often indicated in elderly patients with displaced proximal humerus fractures (PHF). The rate of greater tuberosity (GT) healing varies from 37 to 90% in this population. The aim of this study was to assess greater and lesser tuberosity (LT) fixation and healing on CT scan after RSA for PHF. Our hypothesis was that both GT and LT healing leads to better functional results after RSA for fracture.

METHODS

Our retrospective cohort consisted of 28 patients treated with an RSA for a four-part PHF during the inclusion period. The mean age at surgery was 77 years. Clinical examination and CT scan were performed at a minimum one year follow-up to assess tuberosity position and healing.

RESULTS

The GT healed in 22 patients (78.5%), the LT in 24 patients (87.5%) and both tuberosities were healed in 20 patients (71.5%). Constant score was significantly improved with GT, LT and both tuberosity healing (p = 0.05, p = 0.04 and p = 0.02 respectively). Motion in anterior elevation was improved with GT and both tuberosity healing (p = 0.01 and p = 0.04 respectively). Motion in external rotation was improved with GT and both tuberosity healing (p = 0.01 and p = 0.02 respectively).

CONCLUSION

GT and LT healing was associated with better functional results and active motion. Anatomical reduction and consolidation of both tuberosities is beneficial with a cumulative effect for functional recovery.

Tuberosity union in patients with proximal humerus fractures treated with reverse shoulder arthroplasty: a technical note and exploratory analysis

PURPOSE

The use of reverse shoulder arthroplasty (RSA) to treat complex humerus fractures is increasing, especially in older, osteoporotic patients. Refixation and tuberosity healing are needed to achieve an optimal range of motion (ROM), external rotation, active forward elevation, and patient satisfaction. Proper healing has been reported, however, in only 40-84% of cases. Our study's aim was to describe a simple, reproducible fixation technique designed to improve tuberosity healing.

METHODS

We included 30 patients with acute proximal humerus fractures undergoing RSA (Global Unite Reverse Fracture, DePuy Synthes, Warsaw, IN, USA) with tuberosity reattachment. The humerus stem was cemented in 24 cases. A standardized suture technique with two fiber tapes was used to reattach tuberosities. Clinical and radiological parameters, which were collected one year post-operatively, included ROM, pain level, Constant scores, subjective shoulder value (SSV), and tuberosity healing.

RESULTS

The mean age of the patients was 79.3 years (± 7; range 65-92), and the tuberosity healing rate was 90.0% (27 of 30). Two patients showed migration (one nonunion, one malunion), and another had complete resorption after an initial period of proper healing. Radiolucent lines around the humerus stem occurred in one case, and three patients had scapular notching. The mean SSV was 86% (± 11; range 60-100), the Constant score was 72 (± 10.3; range 48-92), the active forward flexion was 140° (± 14.3; range 115-165), and external rotation was 23° (± 16.5; range 0-50).

CONCLUSIONS

This reattachment technique, which is simple and reproducible, achieved a higher tuberosity healing rate than previously published rates.