The role of continuous passive motion (CPM) versus no-CPM in the treatment of frozen shoulder: A systematic review and meta-analysis

BackhroundsFrozen shoulder or adhesive capsulitis is a condition defined as a gradual developmentof restrictions of active and passive shoulder motions without significant radiologicalfindings other than osteopenia. Frozen shoulder is categorized into two groups, primary(or idiopathic) and secondary that is more prevalent and is associated with conditions suchas diabetes mellitus surgery, trauma, thyroid disease, prolonged immobilization, stroke,autoimmune disease and etc.1,2Its prevalence in Caucasian populations is estimated to be between 2 and %5. It occursmainly in fifth and sixth decades of life and a onset before 40 is rare; women are morecommonly affected than men.3 It occurs predominantly unilateral and the non-dominantshoulder is more likely to be affected and in 6 to 17 percent of patients the other shoulderbecomes involved within five years. 4,5Currently, there is no consensus as to which is the most efficient treatment. The goals inthe treatments are to restore motion, improve shoulder function and to provide pain relief.MethodsFollowing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) guideline, we searched in MEDLINE, MEDLINE preprints, SCOPUS, EMBASE, andthe Cochrane Central Register of Controlled Trials (CENTRAL) for all published clinical studieson the use of continuous passive motion (CPM) for the treatment of frozen shoulder. Wealso crossed checked the bibliographies referenced in the studies identified in the primarysearch. [Figure 1]Eligibility criteriaResults Study characteristics We included 4 studies for data extraction comprising of 208 patients divided into 105 patients treated with the CPM and 103 patients in the controlgroup without utilizing the CPM. The mean age was 61 in 3 studies6,16,17, with one studynot mentioning their patients age18, and the mean follow-up was 18.3 weeks in total.ConclusionsIn two studies both groups showed significant decrease in all measured parameters in the lastfollow-up comparing to the first visit. but no significant difference within groups, except theCPM group had a lower VAS score than the control group with a statistical significance. 6,18In another study all evaluation criteria (including ROM, VAS, SPADI and constant score) wereimproved in both groups. But by the fourth and fifth week there was a statistical differencebetween groups in VAS, SPADI, constant score, abduction, flexion, internal and externalrotation, all in favor of the CPM group. 17In one study, which was conducted for 6 months, both groups were improved in all outcomemeasures but in the end there was no statistical difference in pain and disability and ROMmeasures between groups. 16