Evidence Based etiology and Treatment of Frozen shoulder Jerod Miler

Frozen Shoulder Etiology and Pathology1 The precise cause of frozen shoulder is still unclear. Typically thought of as an inflammatory disorder Thought process is that some insult to the capsuloligamentous complex initiates a runaway cycle of inflammation and subsequent fibrosis. Patients with frozen shoulder exhibit elevated levels of cytokines, an important part of the inflammatory process.

Frozen Shoulder Etiology and Pathology1 The idea inflammation idea has been challenged Multiple studies found no significant evidence of inflammatory cells in tissue samples. Some investigators have visually seen and described synovitis, while others have found angiogensis and even evidence of nerve propagation.

Classification of Frozen Shoulder1,2 JOSPT has two classification systems for patient’s with frozen shoulder. Degrees of irritability High, Intermediate, and low Stages of frozen shoulder progression Pre-adhesive, Adhesive, Frozen, and Thawing phases

Irritability Levels

High Irritability1,2 High pain levels 7+/10 pain reported Constant night and/or resting pain High levels of disability reported on outcome measures Pain occurs before end-range in both AROM and PROM AROM is less than PROM due to pain

Intermediate Irritability1,2 Patient reports 4-7/10 pain ranges Intermittent night and/or resting pain Moderate levels of disability reported on outcome measures Pain occurs at end-range of movements AROM is similar to PROM

Low Irritability1,2 Minimal levels of pain reported No night or resting pain Outcomes measures report low level of disability Pain occurs with overpressure past end-range AROM is the same as PROM

Stages of Frozen Shoulder

Stage 1: Pre-adhesive Stage1 Duration: 0-3 months Pain with active and passive ranges of motion Limitations begin to manifest at end-range flexion, abduction, IR, and ER Patient’s are often misdiagnosed with shoulder impingement. Only slight limitations of ROM when patient is under anesthesia Synovitis is typically seen during arthroscopy.

Stage 2: Freezing Stage1 Duration of 3-9 months Chronic pain with active and passive range of motion ROM deficits in flexion, abduction, IR, and ER are significant ROM is essentially the same when under anesthesia as when the patient is awake. During arthroscopy, capsule is found to be tight, with rubbery end-feel.

Stage 3: Frozen Stage1 Duration 9-15 months Minimal pain except at very end-range of motion. Significant ROM loss with ridged end-feel. ROM is the same under anesthesia as when awake. Arthroscopic findings No hypervascularity, remnants of fibrotic synovium, diminished capsular volume, capsule is thick and full of scar tissue.

Stage 4: Thawing Stage1 15-24 month duration Minimal pain Severe capsular restriction but ROM can gradually increase due to lack of pain.

Evidence of Treatment Methods

Stretching Exercises Stretching exercises do affect pain and increase ROM May not be more beneficial than other methods No consistent evidence has determined the optimal duration, intensity, and frequency for stretching interventions2 JOSPT recommendations state that stretching intensity should be related to irritability level Low duration, low intensity, pain free AAROM with high irritability Longer duration, higher intensity for low irritability1 Poorer outcomes are paired with stretching beyond painful limits2 JOSPT recommendation level: B, moderate evidence

Joint Mobilizations There is some evidence that it may help improve outcomes Little evidence to prove efficacy over other interventions May be used to increase physiological motions at the GH2 Recommendations are similar to stretching Low-grade (I &II) should be used during high irritability High-grade (III&IV) should be used during low irritability JOSPT recommendation level: C, weak evidence

Patient Education The insidious nature of frozen shoulder can be hard for patients to understand and can be frightening to them. Adequate descriptions and explanations of the stages of the pathology can help adequately prepare them for their long recovery process. Physical therapists are recommended to: Explain the process and stages of frozen shoulder Promote activity modifications of functional, pain-free motion. Explain the matching of treatment intensity to irritability levels JOSPT recommendation level: B, moderate evidence

Modalities Heating and electrical modalities theoretically have applicable effects on pain for this population Difficult to assess individual efficacy of each modality Usually applied to adjuncts of other treatments Ultrasound Evidence is mixed on the efficacy1,2

Modalities cont. Superficial heat TENS concurrent with stretching Has been shown to relax muscles and in theory could help with muscle guarding1 More recent studies have shown no improvements for target population Short wave diathermy showed more promising outcomes2 TENS concurrent with stretching May be used to blunt pain response in irritable patients1,2 JOSPT recommendation level: C, weak evidence

Corticosteroid Injection Administered to blunt inflammation of frozen shoulder Some studies hint that muscle guarding may be primary mechanism for ROM restriction in early cases Research shows that patients that receive intra-articular corticosteroid injections in conjunction with mobility and stretching showed the best short term outcomes Correlation less strong for long term JOSPT recommendation level: A, strong evidence

Proposed Treatment Guidelines1,2 High Irritability Mod. Irritability Low Irritability Modalities Heat/Ice/Electrical stimulation Heat/Ice/Electrical Stimulation None Activity Modification Yes ROM/stretch Short duration (3-5s) pain-free passive AAROM Short duration (5-15s) passive, AAROM, and AROM End range/overpressure, increased-duration, cyclic loading Manual Low-grad mobilization Low to high-grade mobilization High-grade mobilization/sustained hold Strengthening Low to high resistance end-ranges Functional activities Basic High demand Patient education Other Intra-articular steroid injections

Questions

References Kelley M, McClure P, Leggin B. Frozen Shoulder: Evidence and a Proposed Model Guiding Rehabilitation. Journal Of Orthopaedic & Sports Physical Therapy [serial online]. n.d.;39(2):135-148. Available from: Science Citation Index, Ipswich, MA. Accessed July 11, 2016 Kelley, Martin J., et al. "Shoulder pain and mobility deficits: adhesive capsulitis: clinical practice guidelines linked to the International Classification of Functioning, Disability, and Health from the Orthopaedic Section of the American Physical Therapy Association." Journal of Orthopaedic & Sports Physical Therapy 43.5 (2013): A1-A31.