Chronic Pain, Rotator Cuff Tendinitis
Conditions
Keywords
Ketamine, Analgesics, Excitatory Amino Acid Antagonists, Receptors, Glutamate, Shoulder
Brief summary
The hypothesis of the present study is that in patients with rotator cuff tendinopathy a specific pharmacological blocking of peripheral glutamate-receptor N-methyl-d-aspartate receptor type1 (NMDAR) glutamate receptors will result in pain alleviation. Activated NMDAR1 has been demonstrated to be crucial for pain regulation in various pain disorders, and in biopsies from patients with tendinopathy, NMDAR1 was found to be activated. To test this hypothesis a specific NMDA receptor antagonist, ketalar (ketamine), will be injected guided by ultrasound into the subacromial space in patients with rotator cuff tendinopathy, and subsequently the pain response will be assessed.
Interventions
DRUGKetalar
2,5 ml - if well tolerated immediately followed by another 2,5 ml - of an approximately 1 mg/ml ketalar solution (1 ml of ketalar 10 mg/ml + 9 ml of NaCl 9%) injected 2 times with 1-12 weeks between each injection
DRUGNaCl 9%
2,5 ml - if well tolerated immediately followed by another 2,5 ml - of a 9% NaCl solution injected 2 times with 1-12 weeks between each injection
Sponsors
Helse Møre og Romsdal HF
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* diagnosis of rotator cuff tendinopathy by exercise-related shoulder pain with positive impingement tests as described by Hawkins and Neers, and MRI findings consistent with tendinopathy. * Symptom duration at least 1 year to ensure neuronal ingrowth and NMDAR expression
Exclusion criteria
* previous surgery in any shoulder. * previous cortisone use, either as injections or orally * symptoms or signs of cervicobrachialgia or polyneuropathy * full thickness rotator cuff ruptures verified by MRI * primary inflammatory mediated pain, hence, patients with glenohumeral arthrosis, glenohumeral arthritis or systemic disorders predisposing for arthritis * a central component of pain perception manifested by radiating pain in the involved limb; implying worse outcome after subacromial decompression. * pregnancy * breastfeeding * reduced liver function (Increased serum bilirubin, ASAT or ALAT), decompensated heart failure (NYHA class 3-4) * increased intracranial pressure or disease of the central nervous system (CNS) * chronic alcoholism * epilepsy * psychiatric disease, increased intraocular pressure * acute intermittent porphyria * hyperthyroidism * use of thyroid hormones * upper respiratory tract infections * pneumonia * intracranial lesions * acute head injuries * ocular injuries * hydrocephalus * risk factors predisposing for intra-articular bleeding * increased risk of infection
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pain | 30 minutes | Comparison of pain assessed by a visual analogue scale both at rest and abduction, after selective N-methyl-d-aspartate receptor type 1 blocking by ketalar injection subacromially controlled against Ringer acetate injection. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pressure pain tolerance | 30 minutes | Comparison of pressure pain tolerance measured in Lbs/cm3, both at rest and abduction, after selective N-methyl-d-aspartate receptor type 1 blocking by ketalar injection subacromially controlled against Ringer acetate injection. |
| Supraspinatus pressure pain threshold | 30 minutes | Comparison of supraspinatus pressure pain threshold measured in Lbs/cm3, after selective N-methyl-d-aspartate receptor type 1 blocking by ketalar injection subacromially controlled against ringer acetate injection |
Countries
Norway
Outcome results
None listed