A Novel Classification in Calcific Tendinitis of the Shoulder: Evaluating MRI Localization and Related Treatment Strategies

Introduction

Calcific tendinopathy (calcific tendinitis) associated with calcific deposits in the shoulder is a common disorder of the rotator cuff tendons. It accounts for up to 7% of all painful shoulders, with the highest prevalence recorded in the fourth and sixth decades. Although the chemical composition of the deposits has been extensively studied across different stages of the disease, the pathogenesis and the factors inducing deposit resorption remain largely unclear. Despite the self-limiting nature of calcific tendinitis, surgical intervention may be required in persistent cases. Surgical treatment primarily involves debridement of the calcific deposit and tendon repair if cuff integrity is compromised. Based on current understanding, calcific tendinitis can be regarded as a form of tendinopathy within the spectrum of rotator cuff tendon disorders.

To date, numerous classification systems have been defined in the literature to characterize calcific deposits in the shoulder. These classifications are based on pathogenesis (Uhthoff-Loehr Classification), plain radiographic imaging(Gärtner-Hayer Classification), and ultrasound imaging (Chiou and Scofienza Classifications). However, none of these systems are directly related to clinical practice or correlate with treatment modalities.

The study aims to establish a novel classification system, based on MRI findings, that is easy to understand and apply, and directly consistent with management options (surgical/conservative). In this study, the aim is to organize the calcific tendinitis patients the investigators have followed according to the system that is recently defined and to evaluate the concordance between the applied treatment modalities and the localization determined by the novel classification.

Materials and Methods

MRI scans, treatment protocols, and operative notes (for those who underwent surgery) of all calcific tendinitis patients followed at the American Hospital and Koç University Hospital since 2004 will be reviewed. Patients will be divided into five groups in the new classification based on the localization of the calcific deposit on MRI. These groups, determined by the location of the calcific deposit, are defined as:

Extratendinous group (E): Calcific deposit located outside the tendon. Intratendinous Articular group (Ta): Calcific deposit located within the tendon, closer to the articular (joint) side.

Intratendinous Bursal group (Tb): Calcific deposit located within the tendon, closer to the bursal side.

Complete Intratendinous group (Tc): Calcific deposit completely encompassing the inside of the tendon.

Intraosseous group (I): Calcific deposit extending into the bone.

To select patients, the MRI scans of all calcific tendinitis cases who presented to and were followed at VKV American Hospital and Koç University Hospital between 2004 and 2025 will be reviewed and grouped according to the aforementioned classification. The operative reports of the patients who were operated on will be examined to determine the surgical procedure performed, and the hospital records of the non-operative patients will be reviewed to determine the conservative treatment methods applied. Patients whose MRI imaging and clinical records are inaccessible or who have conditions precluding clinical evaluation will be excluded from the study. All included patients will be compiled according to the specified classification system. The treatment modalities applied to the patients will be included in the data set, and the relationship between the classification groups and the applied treatment method will be evaluated.

• Conservative non-surgical treatment (Other): Non surgical conservative treatment consist of all the treatment modalities e.g. analgesic treatment (NSAIDs, paracetamol...), ice packaging, movement restriction, resting etc.
• Debridement (Procedure): Debridement intervention can be described as a surgical intervention, which includes debridement of the calcification deposit.
• Side to side repair (Procedure): After the surgical debridement of the deposit, sometimes there is a rotator cuff defect. Side to side repair group consist of the cases when the defect is repaired side to side primarily.
• Anchor Fixation (Procedure): Anchor fixation group consist of the cases when the rotator cuff defect cannot be repaired side to side, and the surgeon managed the defect by fixating it to the bone with an anchor.

Primary outcomes

• Change from Baseline in American Shoulder and Elbow Surgeons (ASES) Score at 12 Months [From preoperative assessment (baseline) to 12 months post-operation]: The ASES score is a standardized shoulder assessment form. It consists of a patient self-evaluation section (visual analog scale for pain and instability) and a daily function assessment section. The score ranges from 0 to 100, where 0 indicates the worst possible outcome and 100 indicates the best possible outcome.

Secondary outcomes

• Change from Baseline in Subjective Shoulder Value (SSV) at 12 Months [From preoperative assessment (baseline) to 12 months post-operation]: The Subjective Shoulder Value (SSV) is a patient-reported outcome measure where the patient assesses the value of their shoulder expressed as a percentage of an entirely normal shoulder. The scale ranges from 0% to 100%, where higher percentages indicate better shoulder function.

Sex: All

Inclusion Criteria

* Patients who underwent surgical treatment for calcific tendinitis
* Presence of single or multiple calcific deposits within the rotator cuff tendons

Exclusion Criteria

* History of prior ipsilateral shoulder surgery for indications other than calcific tendinitis
* Revision surgery for calcific tendinitis
* Incomplete clinical documentation or unavailable MRI data

• Results publication: Seyahi A, Demirhan M. Arthroscopic removal of intraosseous and intratendinous deposits in calcifying tendinitis of the rotator cuff. Arthroscopy. 2009 Jun;25(6):590-6. doi: 10.1016/j.arthro.2008.12.024. PMID 19501287
• Results publication: Birsel O, Caliskan E, Eren I, Yuruk B, Ozben H, Demirhan M. The impact of acromial morphology on the localization and size of calcific tendonitis in the rotator cuff. Acta Orthop Traumatol Turc. 2024 Nov 8;58(5):263-268. doi: 10.5152/j.aott.2024.24035. PMID 39560675
• Results publication: Caliskan E, Eren I, Aslan L, Koyuncu O, Seyahi A, Demirhan M. Intraosseous calcific tendinitis of the rotator cuff yields similar outcomes to those of intratendinous lesions despite worse preoperative scores. Knee Surg Sports Traumatol Arthrosc. 2022 Jul;30(7):2485-2491. doi: 10.1007/s00167-022-06870-2. Epub 2022 Jan 19. PMID 35044474

• Mehmet S Demirhan, Medical Doctor, Principal investigator, Koc University Hospital