title: Medium-term natural history of subacromial impingement syndrome.
abstract: BACKGROUND
  We evaluated the factors that affect the natural course of subacromial impingement syndrome in patients without rotator cuff tears.
  
  
  METHODS
  In total, 63 patients were included. During the first evaluation, we recorded each patient's age, gender, profession, body mass index (BMI), hand dominance, alcohol and tobacco consumption, comorbidities, causative event of pain, presence of a functional limitation, duration of symptoms, shoulder scores (American Shoulder and Elbow Surgeons [ASES], Constant-Murley, and visual analog scale), history of subacromial steroid injections, and magnetic resonance imaging (MRI) classification. A subacromial lidocaine injection test was performed to confirm the diagnosis, and patients were initially treated conservatively. Of the 63 patients, 7 underwent a subsequent surgical procedure. We recalled the patients and questioned them about recurrences. According to their answers, the patients were grouped as follows: group 1, no recurrence; group 2, relapsing course; and group 3, chronic course. We compared the groups regarding the factors proposed to affect the course of the disease.
  
  
  RESULTS
  The mean follow-up time was 8.45 ± 0.9 years. There were no significant differences regarding gender, profession, hand dominance, alcohol consumption, smoking, comorbidities, causative event of pain, visual analog scale score, or history of subacromial steroid injections between groups. The patients in group 1 were significantly younger than those in group 2 (P = .038). The mean BMI value of the group 1 patients was significantly lower than that of the group 3 patients (P = .034). Patients with a functional limitation besides pain tended to have a relapsing course. The Constant-Murley and ASES scores were significantly higher for patients in group 1 than for patients in group 2 (P = .024 and P = .041, respectively). The duration of symptoms was significantly shorter (<3 months) in group 1 (P = .001). Most of the patients in group 1 had reversible changes on MRI (P = .038).
  
  
  CONCLUSIONS
  In our study, younger age, lower BMI, more functional capacity, a shorter symptomatic period, reversible changes on MRI, and higher Constant and ASES scores at the first evaluation were good prognostic factors.
authors.affiliation: Department of Orthopaedics and Traumatology, Ceylanpinar State Hospital, Şanlıurfa, Turkey. Electronic address: drsemaertan@gmail.com.
authors.forename: Sema
authors.initials: S
authors.lastname: Ertan
authors.affiliation: Department of Hand Surgery, Faculty of Medicine, Mersin University, Mersin, Turkey.
authors.forename: Egemen
authors.initials: E
authors.lastname: Ayhan
authors.affiliation: Department of Orthopaedics and Traumatology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Mehmet F
authors.initials: MF
authors.lastname: Güven
authors.affiliation: Department of Orthopaedics and Traumatology, Faculty of Medicine, Istanbul Bilim University, Istanbul, Turkey.
authors.forename: Hayrettin
authors.initials: H
authors.lastname: Kesmezacar
authors.affiliation: Department of Physical Medicine and Rehabilitation, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Kenan
authors.initials: K
authors.lastname: Akgün
authors.affiliation: Department of Orthopaedics and Traumatology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Muharrem
authors.initials: M
authors.lastname: Babacan
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011379:Prognosis; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000601:surgery; D012720:Severity of Illness Index; D019534:Shoulder Impingement Syndrome / Q000503:physiopathology* / Q000601:surgery; D020069:Shoulder Pain / Q000503:physiopathology*
keywords: Subacromial impingement; affecting factors; natural course; rotator cuff; shoulder impingement