Proximal humeral bone defect in reverse shoulder arthroplasty combined with latissimus-dorsi transfer is not related with a poor outcome

Abstract

Background: Reverse total shoulder arthroplasty (RSA) associated with modified L'Episcopo (isolated LD) or L'Episcopo (combined TM and LD) procedures had been confirmed to effectively overcome the expected external rotation deficit in patient with postero-superior massive cuff tear and teres minor deficiency. The objective of this study was to evaluate the radiological bony lesions of the lateral proximal humerus following RSA combined with tendon transfer, and to determine whether these bony lesions affect the clinical outcome.

Material and methods: A retrospective review of 24 RSAs (mean age 68.71 years, range 52-83) associated with modified L'Episcopo procedure (9) and L'Episcopo procedure (15) was performed. X-rays were assessed for lateral cortex lesions and were categorized into either intact, irregular or complete lytic appearances. In addition, signs of stem loosening were assessed. Clinical outcome measures included range of motion, SSV, VAS, and Constant-Murley scores.

Results: With a mean follow-up of 44.71 months (12-97; SD 27.42), eight (33.3%) patients demonstrated intact lateral cortex, eight (33.3%) irregular and eight (33.3%) lytic lesions. 40% of cemented stems demonstrated a deformed cortex compared to 74% of cementless stems. Radiolucent lines were detected in one cemented stem (p=0.046). GT resorption (p=0.147), condensations lines (p=0.449) and spot weld (p=0.342), appeared exclusively in non-cemented stem. Postoperatively all patients (24) demonstrated significant improvements in all clinical and functional parameters. A comparison between patient with (Group 2, 16 patients) and without bony lesions (Group 1, 8 patients) revealed no significant differences in functional scores and range of motion: Constant (p=0,61), VAS (p=0,61), SSV (p=0,66) and external rotation (p=0,34).

Conclusion: At short-term follow-up, RSA combined with L'Episcopo or modified l'Episcopo procedure resulted in high incidence (67%) of lateral proximal humerus lesions. Radiolucent lines were noted in cemented stems whereas, signs of stress shielding and GT resorption appeared in non-cemented stems. Yet, no case of humeral loosening was detected and these lesions did not seem to affect the clinical outcome. The use of cemented straight standard-length humeral stems should be positively considered in RSA associated with LD\TM tendon transfer.

Level of evidence: IV; retrospective study.

Keywords: Bone lesion; External rotation; L’Episcopo; Radiological outcome; Reverse shoulder arthroplasty; Tendon transfer.