Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 27, Issue 12, pp 3944–3951 | Cite as

The association between a low critical shoulder angle and SLAP lesions

  • Thilo PatzerEmail author
  • Nina Wimmer
  • Pablo Emilio Verde
  • Martin Hufeland
  • Ruediger Krauspe
  • Hannes Kenji Kubo



To evaluate the critical shoulder angle (CSA), acromion index (AI) and further acromion parameters in patients with isolated SLAP lesions compared with patients without SLAP lesions.


Between 2012 and 2016, the CSA, AI, lateral acromion angle (LAA) and acromion slope (AS) were radiologically examined in consecutive patients > 18 years having had a shoulder arthroscopy with isolated SLAP lesion types II–IV. These were compared to controls without SLAP lesions and without (control group I) or with (control group II) complete supraspinatus tendon (SSP) tears.


75/103 patients with isolated SLAP lesion types II–IV with a mean age of 46.5 years (± 13.0, 18.1–76.3) were analyzed, 61% of them being male. For control, n = 211 consecutive patients (47% male) with an intact SSP and SLAP complex and a mean age of 52.3 years (± 15.0, 18.6–88.4) and n = 115 patients (60% male) with an intact SLAP complex but complete SSP tears, mean age 66.6 years (± 9.3, 44.7–87.9) were examined. The CSA in SLAP patients was 29.6° (± 3.5, 21.0–38.0), 33.8° (± 3.7, 25.1–46.9) in no SLAP and no SSP (p < 0.001) and 36.7° (± 3.6, 29.1–46.6) in no SLAP but SSP (p < 0.001). The area under the curve (AUC) for CSA was 0.83 for SLAP lesions resulting in a probability of 83% for patients with SLAP lesion to be associated with a specific CSA.


Isolated SLAP lesion types II–IV are associated with a low CSA < 30°. The AI, the AS as well as the LAA showed no correlation with SLAP lesions.

Level of evidence

Retrospective comparative study, Level III.


Shoulder arthroscopy SLAP lesion Critical shoulder angle Acromion index Risk factor Overhead sports 



Acromion index


Area under the curve


Acromion slope


Critical shoulder angle


Exempli gratia; for example




Id est; that is to say


Institutional review board


Infraspinatus tendon


Lateral acromion angle


Long head of biceps tendon


Receiving operating characteristic


Superior labrum from anterior to posterior


Subscapularis tendon


Supraspinatus tendon



There is no funding source.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in concordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.


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Copyright information

© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2019

Authors and Affiliations

  • Thilo Patzer
    • 1
    Email author
  • Nina Wimmer
    • 1
  • Pablo Emilio Verde
    • 2
  • Martin Hufeland
    • 1
  • Ruediger Krauspe
    • 1
  • Hannes Kenji Kubo
    • 1
  1. 1.Orthopaedic Department, Shoulder-Elbow-SectionUniversity of DuesseldorfDuesseldorfGermany
  2. 2.Coordination Center for Clinical TrialsUniversity of DuesseldorfDuesseldorfGermany

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