Korean J Sports Med.  2025 Mar;43(1):41-45. 10.5763/kjsm.2025.43.1.41.

Can It be Said that this Case Confirmed the Phenomenon of Subacromial Suture Knot Impingement after Arthroscopic Rotator Cuff Repair?: A Case Report

• Kim SH
• Choi SW
• Park SH
• Park YB

• KMID: 2565716
• DOI: http://doi.org/10.5763/kjsm.2025.43.1.41

Abstract

Rotator cuff tears are common shoulder injuries, particularly in older adults. Arthroscopic rotator cuff repair (ARCR) is the preferred treatment due to its successful outcomes, but complications like suture knot impingement may arise. Knot impingement, although rare, can lead to subacromial bone erosion and persistent pain. The condition remains under-reported, and direct evidence linking knot impingement to subacromial erosion is scarce. A 63-year-old woman presented with progressively worsening shoulder pain and restricted range of motion, 10 years after undergoing ARCR. Clinical assessment indicated subacromial impingement with positive Neer, Hawkins test results and reduced shoulder mobility. Arthroscopic evaluation revealed suture knots embedded in the subacromial bone, directly causing erosion. This is the first case to confirm through arthroscopy that subacromial bone erosion resulted from knot impingement. This case emphasizes the importance of follow-up and highlights the need to consider alternative suture techniques to avoid complications like knot impingement. Surgeons should be vigilant in minimizing risks associated with suture materials and techniques to improve long-term outcomes for patients undergoing ARCR.

Keyword

Knot impingement; Subacromial erosion; Arthroscopic rotator cuff repair; Shoulder

Figure

• 

  Fig. 1 Plain radiographs of the right shoulder. (A) Anteroposterior and (B) 20° caudal tilting view.

• 

  Fig. 2 Initial T2-weighted coronal magnetic resonance imaging showing irregular subacromial bone erosion (arrows) and rotator cuff retear (arrowhead).

• 

  Fig. 3 Findings during arthroscopy. (A) Suture knot near the musculotendinous junction from the single-row repair. (B) Wire of suture knot attached to the subacromial bone surface. (C) Erosion and suture embedded in the subacromial bone surface. (D) Suture penetrating the bone, visible even after partial cortical bone removal. (E) Post-bridge repair for rotator cuff retear.

• 

  Fig. 4 Plain radiographs of the right shoulder 1 year after surgery. (A) Anteroposterior and (B) 20° caudal tilting view.

Reference

1. Minagawa H, Yamamoto N, Abe H, et al. 2013; Prevalence of symptomatic and asymptomatic rotator cuff tears in the general population: from mass-screening in one village. J Orthop. 10:8–12. DOI: 10.1016/j.jor.2013.01.008. PMID: 24403741. PMCID: PMC3768248.

2. Prabhakar A, Kanthalu Subramanian JN, Swathikaa P, Kumareswaran SI, Subramanian KN. 2022; Current concepts on management of cuff tear. J Clin Orthop Trauma. 28:101808. DOI: 10.1016/j.jcot.2022.101808. PMID: 35402155. PMCID: PMC8983388.

3. Dey Hazra RO, Ernat JJ, Rakowski DR, Boykin RE, Millett PJ. 2021; The evolution of arthroscopic rotator cuff repair. Orthop J Sports Med. 9:23259671211050899. DOI: 10.1177/23259671211050899. PMID: 34901288. PMCID: PMC8652190.

4. Marrero LG, Nelman KR, Nottage WM. 2011; Long-term follow-up of arthroscopic rotator cuff repair. Arthroscopy. 27:885–8. DOI: 10.1016/j.arthro.2011.02.019. PMID: 21620635.

5. Sethi PM, Noonan BC, Cunningham J, Shreck E, Miller S. 2010; Repair results of 2-tendon rotator cuff tears utilizing the transosseous equivalent technique. J Shoulder Elbow Surg. 19:1210–7. DOI: 10.1016/j.jse.2010.03.018. PMID: 20675153.

6. Mihata T, Watanabe C, Fukunishi K, et al. 2011; Functional and structural outcomes of single-row versus double-row versus combined double-row and suture-bridge repair for rotator cuff tears. Am J Sports Med. 39:2091–8. DOI: 10.1177/0363546511415660. PMID: 21785001.

7. Gülecyüz M, Bortolotti H, Pietschmann M, et al. 2016; Primary stability of rotator cuff repair: can more suture materials yield more strength? Int Orthop. 40:989–97. DOI: 10.1007/s00264-015-3012-3. PMID: 26442512.

8. Rhee YG, Cho NS, Parke CS. 2012; Arthroscopic rotator cuff repair using modified Mason-Allen medial row stitch: knotless versus knot-tying suture bridge technique. Am J Sports Med. 40:2440–7. DOI: 10.1177/0363546512459170. PMID: 23002202.

9. Ide J, Karasugi T, Okamoto N, Taniwaki T, Oka K, Mizuta H. 2015; Functional and structural comparisons of the arthroscopic knotless double-row suture bridge and single-row repair for anterosuperior rotator cuff tears. J Shoulder Elbow Surg. 24:1544–54. DOI: 10.1016/j.jse.2015.03.015. PMID: 25940379.

10. Kim SJ, Kim SH, Moon HS, Chun YM. 2016; Footprint contact area and interface pressure comparison between the knotless and knot-tying transosseous-equivalent technique for rotator cuff repair. Arthroscopy. 32:7–12. DOI: 10.1016/j.arthro.2015.07.004. PMID: 26382638.

11. Kim DH, Jeon JH, Choi BC, Cho CH. 2022; Knot impingement after arthroscopic rotator cuff repair mimicking infection: a case report. World J Clin Cases. 10:5097–102. DOI: 10.12998/wjcc.v10.i15.5097. PMID: 35801024. PMCID: PMC9198891.

12. Park YE, Shon MS, Lim TK, Koh KH, Jung SW, Yoo JC. 2014; Knot impingement after rotator cuff repair: is it real? Arthroscopy. 30:1055–60. DOI: 10.1016/j.arthro.2014.04.091. PMID: 24908257.

13. Bakhsh W, Nicandri G. 2018; Anatomy and physical examination of the shoulder. Sports Med Arthrosc Rev. 26:e10–22. DOI: 10.1097/JSA.0000000000000202. PMID: 30059442.