Onlay Uncemented Lateralized Reverse Shoulder Arthroplasty for Fracture Sequelae Type 1 with Valgus/Varus Malunion: Deltoid Lengthening and Outcomes

Abstract

The successful treatment of proximal humeral fractures remains challenging for shoulder surgeons, and failure rates are high, regardless of initial treatment. This study aimed to analyze the clinical and radiographic midterm results of onlay lateralized cementless stem reverse shoulder arthroplasty (RSA) in patients with valgus/varus malunion proximal humerus fracture sequelae without metaphyseal osteotomy. We retrospectively studied 35 cases with the diagnosis of fracture sequelae of the proximal part of the humerus with valgus/varus malunion. The mean duration of follow-up was 4.6 years (range, 2 to 7 years), and the mean time between fracture and arthroplasty was 6 years (1 to 32 years). Seventeen patients (48.6%) had initially been treated nonoperatively. The Constant score (CS), active range of motion, and radiographs of the affected shoulders, as well as the acromion to greater tuberosity (AGT) distance and deltoid length (DL), were analyzed before surgery and at their latest follow-up. A total of thirty-three patients (94.3%) rated their outcome as very good or good. Mean CS, forward flexion, and external rotation improved significantly (p < 0.0001), as did internal rotation and pain (p < 0.05). AGT distance significantly increased postoperatively from 14.7 to 43.3 mm, as did DL from 143 to 170 mm (p < 0.05). There was no correlation between the outcomes and valgus/varus deformity, previous surgeries, or AGT distance/DL. A total of four complications occurred (11.4%): two dislocations were detected (5.7%) and successfully revised with a longer cemented stem. Onlay lateralized uncemented stem RSA improves clinical outcomes and decreases complications when treating valgus/varus malunion fracture sequelae, avoiding intraoperative technical challenges, such as tuberosities osteotomy conscious of bone loss and proper deltoid tensioning.

Problems, complications, and reinterventions in 4893 onlay humeral lateralized reverse shoulder arthroplasties: a systematic review (part I—complications)

“…Biomechanically, lack of compressive forces between the glenosphere and humeral socket are the main parameters associated with instability, consequent to a loss of tension of the deltoid and the remaining cuff associated with proximal bone resorption in late dislocations. Small glenoid size, the deltopectoral approach, poor subscapularis muscle condition, revision surgery, younger male patients, association with scapular notching, resorbed tuberosities/proximal bone loss, and inadequate humeral length or version were all reported to be factors relating to higher rates of instability [ 11 , 22 , 65 , 67 , 68 ].…”

Anterior deltoid muscle tension quantified with shear wave ultrasound elastography correlates with pain level after reverse shoulder arthroplasty

“…[26] Since the publication of a study by Ascione et al showing an increased prevalence of scapular spine fractures after RSA with an onlay-design (i.e. with additional lengthening of the arm due to a humeral onlay polyethylene component) everybody should be aware of the risks of overlengthening the arm [27].…”

Problems, complications, and reinterventions in 4893 onlay humeral lateralized reverse shoulder arthroplasties, a systematic review: part II—problems and reinterventions

“…Scapular notching was the most frequently reported problem after the analyzed RSA, even though it did Nevertheless, scapular notching remains a concern of relevance certain etiologies, such as fracture sequelae [57]. Grubhofer et al [33] studied 44 shoulders operated on after failed osteosynthesis of proximal humeral fractures; 41 out of 44 cases (93%) were affected by scapular notching, and it was the only study that reported a stage 4 notching (4 cases).…”