ISAKOS: 2023 Congress in Boston, MA USA

2023 ISAKOS Biennial Congress ePoster

 

Risk Factors For Abduction Notching After Reverse Total Shoulder Arthroplasty

Hyeon Jang Jeong, MD, PhD, Seongnam-Si, Gyeonggi-do KOREA, REPUBLIC OF
Sang Woo Kim, MD, Seoul KOREA, REPUBLIC OF
Sung-Min Rhee, MD, Seoul, Seoul KOREA, REPUBLIC OF
Ji Hyun Yeo, MD, Hanam KOREA, REPUBLIC OF
Yoo-Sun Won, MD, Seongnam KOREA, REPUBLIC OF
Jae Woo Park, MD, Seongnam KOREA, REPUBLIC OF
Seok Won Lee, MD, Seongnam KOREA, REPUBLIC OF
Myung Jae Hyun, MD, Seongnam KOREA, REPUBLIC OF
Joo Han Oh, MD, PhD, Seongnam-Si, Gyeonggi-do KOREA, REPUBLIC OF

Seoul National University Bundang Hospital, Seongnam, KOREA, REPUBLIC OF

FDA Status Not Applicable

Summary

Abduction notching correlated with patients’ anatomical characteristics and the degree of lateralization during reverse total shoulder arthroplasty. To prevent abduction notching, surgeons should adjust the implant’s degree of lateralization according to patients’ anatomical characteristics.

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Abstract

Background

Scapular notching is a well-known postoperative complication of reverse total shoulder arthroplasty (RTSA). However, abduction notching (AbN), a subacromial erosion caused by repeated abduction impingement after RTSA, has not been previously reported in a clinical setting. Therefore, this study aimed to assess the risk factors and functional outcomes of AbN after RTSA.

Methods

We retrospectively reviewed the medical records of 125 patients who underwent RTSA with the same design and had at least two years of follow-up between March 2014 and May 2017. AbN was defined as subacromial erosion observed at the final follow-up but not on the X-ray three months after surgery. Radiologic parameters representing the patient's native anatomy and degrees of lateralisation and/or distalisation during surgery were evaluated using preoperative and three months postoperative X-rays. The visual analogue scale of pain (pVAS), active range of motion (ROM), and American Shoulder and Elbow Surgeons (ASES) score were assessed preoperatively and at the final follow-up to evaluate the functional outcomes of AbN.

Results

AbN occurred in 12.8% (16/125) of enrolled patients during the study period. Preoperative centre of rotation-acromion distance (CAD) (p = 0.009) and postoperative humerus lateralisation offset (HL), which evaluated the degree of lateralisation after RTSA (p = 0.003), were risk factors for AbN. The preoperative CAD and postoperative HL cutoff values were 14.0 mm and 19.0 mm, respectively. The pVAS (p = 0.01) and ASES score (p = 0.04) at the final follow-up were significantly worse in patients with AbN.

Conclusions

Abduction notching correlated with patients’ anatomical characteristics and the degree of lateralisation during RTSA. To prevent abduction notching, surgeons should adjust the implant’s degree of lateralisation according to patients’ anatomical characteristics.