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Frozen Shoulder

Adhesive capsulitis management: diagnostic criteria, systemic risk factors (diabetes/thyroid), and the transition from conservative therapy to hydrodilatation or manipulation.

38 citationsUpdated Jun 2026

For patients: a plain-language version of this topic is available. See the patient guide.

Overview

Frozen shoulder is a painful global restriction of glenohumeral movement, active and passive, in the absence of a structural lesion that explains it. The clinical entity is not in doubt. What is in doubt is almost everything that is traditionally taught about it: that it passes through three discrete stages, that it is reliably self-limiting, that it resolves completely, and that treatment should be selected by stage. Each of those propositions traces to a small number of mid-twentieth-century papers whose methods do not support them, and the best modern evidence either fails to confirm them or contradicts them outright [1][2][4].

The practical consequences are large. If the condition is not dependably self-limiting, "wait and it will pass" is not a neutral option. If the stages cannot be assigned reliably, stage-based treatment algorithms are built on sand. And if — as the UK FROST trial found — early structured physiotherapy with an injection, manipulation under anaesthesia and arthroscopic capsular release all land within a few points of each other at one year, then the choice between them turns on cost, risk and patient preference rather than on efficacy [16].

This page sets out what the evidence actually supports, and is explicit about where it runs out.

The three-stage model: where it came from, and why it does not hold

The freezing / frozen / thawing model is usually attributed to Reeves in 1975 [2]. Its provenance is worth knowing. Codman coined "frozen shoulder" in 1934 to describe what he took to be a degenerative cuff disorder; Neviaser proposed "adhesive capsulitis" in 1945 on the basis of ten surgical cases with microscopic capsular degeneration. Reeves then proposed the three-phase natural history after — in Wong's words — "mistakenly combining citation information for Neviaser's 1953 partial rotator cuff tear and 1945 adhesive capsulitis articles" [1]. The companion claim that the condition resolves completely comes from Grey in 1978 [3], characterised by Wong as "a one-page cohort study without reported methods or objective measures" [1].

Three specific problems undermine the model.

The stages may be an artefact of Reeves' own protocol. Reeves rested his patients' arms in slings for up to nine months. As Wong puts it: "After placing the painful shoulders in slings for up to 9 months, the shoulders were unsurprisingly found to be in a phase of stiffness. When movement was subsequently allowed, stiffness began to subside in what was dubbed the 'recovery' phase" [1]. A treatment protocol that immobilises and then mobilises will generate a stiffening-then-loosening curve in almost any shoulder.

The predicted recovery pattern does not occur. Wong screened 508 citations and included seven studies (234 subjects, 239 shoulders). None showed the slow-early, faster-late trajectory the model predicts. The opposite was found: "moderate-quality evidence from three randomised controlled trials with longitudinal data demonstrated that most improvement occurred early, not late" [1]. Wong graded the evidence for both limbs of the theory — progression through phases, and complete recovery without treatment — as very low quality, and recommended that reference to it "should be discontinued" [1].

The phases were never discrete, even as originally described. Reeves' own durations overlap: 10–36 weeks painful, 4–12 months stiff, 5–26 months recovery [1]. Even the sympathetic reviews concede "three overlapping phases" [6]. And the thawing figure has drifted in the secondary literature — 5–26 months in the primary source, but 12–42 months in three widely-read reviews [6][13][14][11], all citing back toward Reeves. This is precisely the citation drift Wong indicts, and it means the numbers quoted to patients about how long the "thawing phase" lasts may have no primary source at all.

To this can be added a mechanistic problem: part of the measured restriction is not capsular. In two small series of patients listed for capsulotomy, passive range improved dramatically under general anaesthesia — abduction gains of 44–83° in one series, and 55° of abduction with 25° of external rotation in the other [11]. If a substantial share of the "frozen" restriction abolishes with anaesthesia, then clinical range of motion — the variable the stages are defined by — is not a clean readout of capsular pathology.

Does stage predict treatment response? This is the question that would justify stage-based algorithms, and there is exactly one study addressing it directly. In 146 patients undergoing manipulation, outcomes were compared across four "stages" — but those stages were defined purely by patient-reported duration of pain (0–3, 3–9, 9–15 and over 15 months), with no examination, imaging or arthroscopic input at all [35]. The authors' conclusion, that manipulating before reaching stage 4 may give better outcomes, is really a statement about operating before 15 months. A duration threshold is a useful thing to know, but it is not a validated pathological stage.

The vocabulary itself tells the story. The consensus definition of frozen shoulder — the one obtained by surveying the specialist community — does not contain the word "stage" even once [8].

What to do instead. The defensible replacement is not another staging system but a description of the trajectory: most recovery happens early and then plateaus, and the plateau may be permanent [1]. Clinically, distinguishing a pain-predominant from a stiffness-predominant presentation is more useful than assigning a numbered stage, and is the language UK FROST adopted [16].

Natural history: what the evidence actually shows

The single most-quoted reassurance — that frozen shoulder resolves on its own — deserves close reading, because the same dataset supports two very different numbers.

Vastamäki reviewed roughly 15,000 outpatient records, identified 231 patients with idiopathic frozen shoulder, and reported that 94% of the untreated group "recovered to normal levels of function and motion without treatment" at a mean of 9 years (range 2–27) [4]. Two caveats change the complexion of that figure:

  • "Recovered" means within 10° of the other shoulder in each of three planes — not restoration of normal absolute range, and referenced against a contralateral shoulder that had itself been frozen in 18 of 103 patients [4].
  • The 94% is of the 51 untreated completers, not of the 231 identified. Most of the original cohort chose treatment or did not participate, commonly citing "poor physical condition". Re-analysing on an intention-to-treat basis, Wong put the proportion returning to full function without treatment at 26% [1].

Vastamäki's own detail also qualifies the headline: only 51% were entirely pain-free at rest, at night and on exertion; 24% had a Constant–Murley score below 80; and 20% were not satisfied [4]. Median symptom duration was 15 months untreated and 20 months after non-operative treatment, with 14% and 29% respectively exceeding two years [4].

The wider literature disagrees violently, and Vastamäki says so twice — of the discrepancy with Reeves, "We cannot explain this difference" [4]. Across the series he tabulates, the proportion left with measurable restriction ranges from 10% to 90%, and Reeves' own five-to-ten-year figures were 39% full recovery, 54% clinical limitation without functional disability and 7% functional limitation [4][6]. Shaffer found half of 61 patients still had pain or stiffness at a mean of seven years [6][14]. UK FROST's background states that "even after an average of ≥ 4 years from onset, around 40% of patients can have mild to severe symptoms" [16].

Wong's summary is the honest one: no included study "documented an objectively measured return to normal range of motion of the shoulder" [1].

The largest long-term series puts numbers on the residue. Of 269 shoulders in 223 patients followed a mean of 4.4 years from onset (range 2–20 years), 59% were near normal, 35% had mild-to-moderate symptoms and 6% had severe symptoms — so 41% had ongoing symptoms, of which 94% were mild and pain was the commonest complaint [34]. The most important observation in that paper is not the proportion but the shape of the curve: near-normal shoulders predominated only after three years, leading the authors to conclude that "symptoms improve in the first 3 years from onset and that this improvement then ceases" [34]. Recovery does not merely take a long time; at some point it stops.

"Supervised neglect" deserves the same scepticism. The systematic review that reported it as the best-performing conservative option rests that finding on a single study, allocated by calendar period rather than randomised, assessed by a single unblinded assessor, with the longest follow-up of any included trial, and with range-of- motion figures back-converted from a functional score rather than measured [5]. The authors themselves decline to endorse it without a fair comparison, and their recommendation of record is physiotherapy [5].

Pathophysiology

The mainstream account is a pathological process of synovial inflammation followed by capsular fibrosis, with the cause unknown [14]. Histologically there is fibroblastic and myofibroblastic proliferation laying down a dense type I and type III collagen matrix which subsequently contracts, accompanied by mast cells, macrophages, T and B lymphocytes and raised IL-1β, IL-6, IL-8, TNF-α and matrix metalloproteinases [6][11][13][14]. The MMP:TIMP ratio has been reported as almost ten times lower than in controls [11]. Alarmins (HMGB1, IL-33, S100A8/9) are elevated and associate with neo-innervation and patient-reported pain [11].

Two observations argue that this is not simply a local capsular disease:

  • It behaves like a fibromatosis. The resemblance to Dupuytren's disease is close enough that Bunker proposed the shoulder lesion is a fibromatosis, and the matrix metalloproteinase inhibitor marimastat induces conditions resembling both [13].
  • It has a systemic genetic architecture. A genome-wide association study identified five loci and, by Mendelian randomisation, found type 1 diabetes to be causal (OR 1.03, 95% CI 1.02–1.05, p = 3×10⁻⁶). The evidence for type 2 diabetes was weaker and did not replicate (OR 1.10, 95% CI 0.99–1.22, p = 0.07). The authors also report no evidence that obesity is causal — the observational obesity association disappeared once diabetes was accounted for (adjusted BMI OR 1.03, 95% CI 0.97–1.09) — and conclude that diabetes influences risk "through glycemic rather than mechanical effects" [12].

The anatomical focus is the rotator interval — the coracohumeral ligament in particular, whose thickening and shortening is the principal restraint to external rotation, with contracture spreading to the whole capsule in more advanced disease [5][11]. Mapping contracture to lost movement: antero-superior capsule (rotator interval, superior glenohumeral and coracohumeral ligaments) restricts external rotation in adduction; antero-inferior capsule restricts external rotation in abduction; posterior capsule restricts internal rotation [13].

What it looks like at arthroscopy. The joint is small — a volume of 3–4 mL against a normal 10–15 mL — with a thickened capsule that is difficult to penetrate and navigate [7]. The striking feature is angiogenesis, most marked in the rotator interval adjacent to the base of the long head of biceps, appearing in the infraglenoid recess as radially aligned vessels Bunker describes as a "lava flow"; as the disease becomes stiff and contracted the angiogenesis declines and a thick white scar becomes visible and palpable within the capsule, sometimes covering the top edge of subscapularis [7]. There is loss of the axillary fold and a tight anterior capsule, with mild or moderate synovitis and no adhesions [6]. "Adhesive capsulitis" is therefore a misnomer, and capsular thickening independent of adhesions has been identified as a primary restriction to movement [1].

Nomenclature and definition

There is no validated diagnostic criterion set. Diagnosis remains clinical, "without formally adopted criteria", and no clinical identifier proposed by expert consensus has been validated for early disease [1].

A consensus definition does exist, obtained by surveying the American Shoulder and Elbow Surgeons membership (190 of 211 responded): "Frozen shoulder is a condition characterized by functional restriction of both active and passive shoulder motion for which radiographs of the glenohumeral joint are essentially unremarkable except for the possible presence of osteopenia or calcific tendonitis" [8]. Agreement was 82% for the definition and 85% for the primary/secondary split, but only 66% for subdividing secondary disease into intrinsic, extrinsic and systemic types [8]. This is a definition arrived at by agreement, not validated against an external standard — and the Gwark data above show what happens when it is tested [9].

Bunker has argued the name should change to contracture of the shoulder [7]. His logic is worth following because it is also a diagnostic argument. Only two pathologies restrict passive external rotation: damage to the joint surface (arthritis, head-splitting fracture, locked dislocation — all of which have an abnormal radiograph), and contracture of the ligaments. If passive external rotation is restricted and the radiograph is normal, the condition "can only be due to contracture of the ligaments" [7]. He notes that "adhesive capsulitis" has "no adhesive nor adhesions", that the French "capsulite rétractile" describes a capsule that is contracted rather than retracted, and that on the evidence capsular contracture accounts for only about 5% of shoulder disease — making frozen shoulder "an overused as well as misused term" [7].

Whatever term is used, the clinically important discipline is Dias's: "In clinical practice, the tendency is to label any patient with a stiff, painful shoulder as a case of frozen shoulder. This should be resisted" [6].

Clinical presentation

The presentation is insidious shoulder pain, severe and characteristically worse at night, followed by progressive global stiffness. The pathognomonic finding is near-complete loss of passive external rotation [6]; loss of passive as well as active movement is what separates frozen shoulder from a painful arc or cuff weakness. UK FROST's operational definition — passive external rotation less than 50% of the opposite side, with normal radiographs — is a practical entry criterion [16].

Peak age is the mid-fifties and onset before 40 is uncommon [6]. Women are affected more often than men, and the non-dominant and left shoulders slightly more often than the dominant and right [6][11]. Prevalence is usually quoted at 2–5%, though the only figure attributed to a named prospective population-based design is a 3-year incidence of about 1% [1][13][14]. Bilateral involvement occurs in 6–17%, usually within five years and typically after the first shoulder has settled [6].

Associations to ask about. Diabetes is the strongest — quoted at 10–36%, with type 1 disease of long duration carrying the highest risk, and glycaemic control acting as a dose-response variable [6][11][14]. Also thyroid disease (especially hypothyroidism), Dupuytren's disease, hyperlipidaemia, cardiac and pulmonary disease, Parkinson's disease, and onset after cardiac surgery, catheterisation, neurosurgery or radical neck dissection [6][14]. Comorbidity is reported in 85% of patients, with 37.5% having more than three [11].

What must be excluded. Radiographs are normal in frozen shoulder and exist to exclude other causes — glenohumeral arthritis, locked posterior dislocation, and destructive lesions. Post-traumatic stiffness is maximal at the start and lessens, the opposite of the frozen shoulder pattern; disuse stiffness lacks the pain; and complex regional pain syndrome, septic arthritis, tuberculosis and tumour can all masquerade as a stiff painful shoulder [6][13].

Investigations

Frozen shoulder is a clinical diagnosis and imaging is confirmatory or exclusionary rather than diagnostic.

  • Radiographs should be normal; their role is exclusion [6].
  • Ultrasound can demonstrate coracohumeral ligament thickening and rotator interval changes, and is useful for excluding cuff pathology.
  • MRI may show thickening of the capsule and coracohumeral ligament, but Dias's observation that it "may show a slight thickening" is the appropriate register [6]. MRI findings should not displace clinical judgement in prognosis or treatment selection.

Can imaging assign a stage? Only partly. A state-of-the-art review found that T2 signal hyperintensity and axillary capsule thickening are characteristic of the early stages, but concluded that "MRI alone cannot completely define the disease stage" [10]. Even individual signs are contested — the association between subcoracoid fat obliteration and stage is described as controversial, with no conclusion possible as to whether it reflects inflammation or fibrosis [10]. The frequently repeated claim that arthroscopic stage correlates with clinical examination and histology rests on a single uncited secondary sentence [6], and the arthroscopic system described has four stages against the clinical model's three — the two have never been reconciled.

Can two clinicians agree on a stage? Nobody has published the measurement. The authors of the consensus definition concede the point themselves: "Our initial analysis of reliability has shown good results, yet sufficient data are not available to confirm this aspect of the classification. There is clearly a limitation of this exercise" [8]. The "initial analysis" referred to is never presented — no numbers, no method, no kappa. A classification in near-universal clinical use has, on this evidence, never been shown to be reproducible.

How reliably can "primary" be diagnosed at all? This is the more troubling question. When 168 patients carrying a clinical diagnosis of primary frozen shoulder — made on examination, history and normal radiographs using the Zuckerman and Rokito criteria — were systematically investigated with blood tests and MRI, only 5 patients (3.0%) remained classifiable as primary. The other 97% had previously undiagnosed systemic abnormality, intra-articular pathology, or both: dyslipidaemia in 88.7%, thyroid abnormality in 25.6%, diabetes in 9.5%, and an intra-articular lesion on MRI in 48.2% (most often a supraspinatus tear, 31.5%) [9]. On that evidence, "primary" frozen shoulder is substantially a diagnosis of insufficient investigation, which is worth remembering before attributing a stiff shoulder to an idiopathic process.

Treatment

Principles

Three things are reasonably well established. First, an intra-articular corticosteroid injection produces a real and clinically meaningful improvement in pain and function over the first 6–12 weeks, and is the only intervention in a 65-study review to clear both statistical significance and a pre-specified minimal clinically relevant difference [15]. Second, that advantage is short-lived, and by 4–6 months most interventions are indistinguishable [15]. Third, at one year the three secondary-care options tested head to head — early structured physiotherapy with injection, manipulation, and arthroscopic release — differ by less than the minimal clinically important difference [16].

A humbling pair of numbers should temper any injection-first enthusiasm. In Challoumas's own subgroup analyses, an intra-articular placebo beat no treatment by −1.6 VAS points, and adding a home exercise programme to placebo or no treatment gained −1.4 VAS points — both larger than the −1.0 point advantage of real steroid over control at 8–12 weeks [15].

Intra-articular corticosteroid

Against no treatment or placebo, steroid improved pain by −1.4 VAS points at 2–6 weeks and −1.0 at 8–12 weeks, with function effect sizes of 0.6 at both timepoints — all clinically as well as statistically significant, and confirmed on trial sequential analysis [15]. External rotation gains were statistically significant but below the 10° threshold (4.7° and 6.8°) [15]. By 4–6 months, mid-term pain was no different from control, and the only surviving differences fell below the review's own clinical threshold [15]. Long-term data were inadequate to analyse at all [15].

Site matters less than expected: subacromial administration "appeared to be as efficacious as" intra-articular, with the differences favouring the intra-articular route falling below clinical thresholds [15]. Moving the needle further away does not help either — in a randomised trial using an identical injectate, an ultrasound-guided suprascapular nerve block was, if anything, slightly worse than an intra-articular injection on 2 of 20 outcomes and better on none [20].

Challoumas's recommendation is to offer steroid at first contact together with a home exercise programme, explicitly against the stepped approach of starting with physiotherapy [15]. Note that this recommendation is strongest for symptoms of less than one year's duration, which is where most trial patients sat [15].

Physiotherapy

The evidence here is weaker than its ubiquity suggests, and the detail matters.

Physiotherapy without an injection is inferior to an injection early on. The Cochrane review's headline comparison found manual therapy plus exercise achieved 26 points less pain improvement and 25 points less function improvement than glucocorticoid injection at seven weeks, with global treatment success 46% versus 77% (NNT 4) [17]. Those differences were gone by 6–12 months [17].

Adding physiotherapy to an injection adds little that patients notice. Cochrane found no clinically important benefit over injection alone [17]; Challoumas found the added value confined to early external rotation (+11.6°) with nothing at 8–12 weeks or 4–6 months [15].

No trial has compared manual therapy plus exercise against placebo or no treatment at all [17]. This is the structural gap that makes any disease-modification claim unsupportable.

Intensity and technique appear not to matter. This is the most useful finding for counselling patients and physiotherapists, and it is consistent across three comparisons. End-range, high-grade mobilisation versus pain-free, low-grade mobilisation showed no significant difference on any of 17 outcomes at 6 or 12 months [17]. Frequency of end-range mobilisation (more than twice weekly versus weekly versus less) produced differences in abduction of 0.6–7.1°, all crossing zero [17]. Head-to-head comparisons of technique — anterior versus posterior glide, PNF versus conventional exercise, dumbbell versus bare-handed — were almost all non-significant [17]. Equally, there is no evidence of harm from working at end range: pain and night-pain outcomes were essentially identical between high- and low-grade arms [17].

Individual techniques do not rescue it. Adding sustained inferior-capsule traction to conventional mobilisation gave a 0.5-point VAS advantage but no difference in flexion or abduction gain (p = 0.36 and 0.55) over two weeks, with no adverse events [30]. Neuromuscular exercise on a motorised platform outperformed strengthening on pain, flexion and external rotation at 8 weeks, but in 40 early-stage non-diabetic patients with no function measure and no follow-up [31]. A sham-controlled trial of strictly pain-free scapular mobilisation and posterior capsule stretch added to injection and exercise reported large benefits to 6 months, but its sham arm also improved substantially, and the authors themselves note this "suggests that FS may resolve naturally following an [injection] without additional targeted treatment" [33].

There is a worthwhile irony in UK FROST here. Its early structured physiotherapy arm was described as including hands-on mobilisation "increasingly stretching into the stiff part of the range", but its own delivery log records manual mobilisation in only 11–27% of those patients and supervised stretching in a single patient [16]. What was actually delivered, and what performed within a few points of surgery at one year, was overwhelmingly education, a steroid injection, supervised gentle active exercise and a graduated home programme.

Hydrodilatation

The evidence is genuinely contradictory, and the two meta-analyses do not even share studies.

  • Challoumas found that adding arthrographic distension to steroid improved short-term pain (−0.9 and −0.8 VAS, high certainty) but not function or external rotation — and both pain effects fall below the 1-point clinical threshold [15].
  • Poku found the mirror image: no pain benefit at either timepoint, but passive external rotation improved (SMD 0.43 early, 0.68 late) with an early disability gain [18]. Poku's own verdict is that "its clinical relevance remains unclear" [18].
  • Chen reported a significant pooled pain benefit, but the subgroup that actually isolates hydrodistension without an added manipulation is non-significant (−0.51, 95% CI −1.27 to 0.26), and heterogeneity ran at 97–99% [19].

Poku and Chen share zero included trials — they synthesise disjoint literatures, so they are not two independent confirmations of anything [18][19].

Practical points: injectate volume ranged from 9 to 100 mL across studies and its effect could not be assessed; most "hydrodilatation" arms contain steroid, so the comparison is usually steroid plus volume versus steroid; and capsular rupture is a mechanistic hypothesis, not a measured predictor of outcome [18]. Reported complications are mostly transient (flushing, depigmentation, post-injection pain, vasovagal syncope, a few hours of sensory and motor loss) but include two glenohumeral joint infections [18].

UK FROST did not include a hydrodilatation arm because only 5% of clinicians used it at design stage; an informal re-survey found 52 of 78 respondents now do, and a three-arm trial of hydrodilatation versus physiotherapy-with-steroid versus manipulation-with- steroid is the trial's top research recommendation [16].

Manipulation under anaesthesia

Manipulation emerged from UK FROST as the most cost-effective option, at an ICER of £6,984 per QALY and an 86% probability of being cost-effective at £20,000 [16]. It produced the most QALYs overall [16].

Adding a steroid injection to the manipulation speeds up the first week or two but changes nothing by 3 and 6 months. In a propensity-matched cohort, the only surviving SPADI benefit was pain at one week; external rotation was better by 4.6° at two weeks and 5.4° at four weeks; global impression of change was equivalent at 4 weeks, 3 months and 6 months [21]. Dislocation occurred in 1 of 141 (0.7%), with no fracture or nerve injury [21].

Recurrent stiffness after manipulation is the main limitation, quoted at 3–40%, with repeat manipulation required in 17.8% of one 730-patient series and 36% versus 15% in diabetic versus non-diabetic shoulders [14].

Arthroscopic capsular release

Against manipulation, arthroscopic release does not deliver clinical superiority. A meta-analysis of 8 comparative studies (768 patients) found equivalent pain relief at 3 and 6 months, equivalent ASES and Constant scores, and equivalent forward flexion and external rotation at every timepoint. Release was statistically better for pain beyond 12 months by 0.44 VAS points — below the 1.4-point threshold — and carried roughly four times the odds of a severe complication (2.37% vs 0.51%; OR 4.14, 95% CI 1.01–16.94) [22]. The authors' conclusion is that "ACR fails to provide clinical superiority over MUA for the treatment of refractory FS" [22].

UK FROST found the same pattern from the other direction: release was worse than both comparators at 3 months (−4.72 OSS points versus physiotherapy, −3.36 versus manipulation), caught up by 6 months, and was ahead of physiotherapy by 3.06 points at 12 months — again below the 5-point threshold [16]. It generated 8 of the 10 serious adverse events, cost £1,734 more than physiotherapy, and returned an ICER above £100,000 per QALY [16]. Its one genuine advantage is definitiveness: 4% needed further treatment, against 7% after manipulation and 15% after physiotherapy [16].

Uncontrolled series report excellent results — Kanbe's 267 shoulders reached a mean ASES of 97.8 at 5 years with a deliberately partial release sparing the infero-posterior capsule [25]; Ziegenfuss's 51 full-thickness 360° releases matched the patient's own contralateral shoulder on every plane at 24 months with no complications [27]; Smith's 136 patients achieved a mean 16 days to good pain relief with 99% saying they would recommend it [23]. These cannot be compared with each other: they differ in severity, aetiology mix, scoring instrument and rehabilitation intensity.

Extent of release — better evidenced than often assumed, and it does not favour going bigger. A systematic review and meta-analysis of 18 studies (629 patients, 811 shoulders) compared anterior-inferior release, anterior-inferior-posterior release, and 360° release. It concluded that less extensive releases gave better functional and pain scores, that adding a posterior release yields early internal rotation which is not sustained (though flexion gains are), and that a complete 360° release "may not provide any further benefit". Complication rates did not differ between the three techniques [36].

Two Level I randomised trials test the posterior extension directly. Kim found no benefit (ASES 91.3 vs 79.5, p = 0.12; forward flexion 145.2° vs 143.3°, p = 0.28) [37]. Chen found extended inferior glenohumeral ligament release gave faster early recovery — abduction 154° vs 119° at six weeks (p < 0.05) — but no difference at 6 or 12 months, at a power of over 0.9 [38]. Kanbe deliberately spares the infero-posterior capsule to protect stability and the axillary nerve [25], while Ziegenfuss and Chiu deliberately release it — and all three report no axillary nerve injury and no dislocation [25][27][28]. Notably, Ziegenfuss's own 12-month figures were "consistent with" a published partial-release series [27].

Aetiology affects outcome, but modestly. Idiopathic disease did best in Galasso's 78-patient series, with idiopathic aetiology independently associated with a higher postoperative Constant score. The raw gap was 90.0 (idiopathic) versus 88.2 (post-operative) and 88.7 (post-traumatic), against a mean improvement of 53–59 points in every group — a difference well below the Constant MCID [26]. All three groups did well.

Timing. The threshold for calling conservative treatment failed varies threefold across series, from 3 months to 9 [22][24][26][28]. No study in this evidence base compared early against late release. Smith found no correlation between symptom duration and 12-month Oxford score (r = −0.07) and operated on night pain alone "regardless of the duration of symptoms" [23]. Against that, Kanbe found longer preoperative duration predicted more severe biceps–coracohumeral adhesion (p = 0.0012), which in turn predicted worse 5-year outcome [25]. Skaliczki's negative finding is the most policy-relevant: total symptom duration was "not influenced by the type of treatment" [24].

Diabetes

The evidence is genuinely split and should be presented to patients as such.

Kanbe found diabetes the dominant risk factor for the severe-adhesion phenotype (OR 6.97, 95% CI 2.35–20.66), with diabetes prevalence rising from 14.2% to 44.4% across severity types, and the severe type reaching only ASES 91.2 versus 99.3 [25]. Smith found no difference in patient-reported outcomes but markedly worse objective end range — 48% versus 79% regaining flexion beyond 160° (p < 0.01) — and made the point that end range may not matter to an inactive older patient but matters to an active fifty-year-old [23]. Galasso and Skaliczki found no association with outcome at all [24][26]. UK FROST, which stratified randomisation by diabetes, found no significant treatment-by-diabetes interaction, though diabetic patients did worse in all arms [16].

None of these papers reports glycaemic outcomes after steroid injection. One study systematically withheld steroid from patients with a fasting glucose ≥ 8.0 mmol/L, so it cannot speak to safety in poorly controlled diabetes [21].

Coexisting rotator cuff tear

Where a repairable cuff tear coexists with a stiff shoulder, the stiffness does not need treating first. In a 212-patient cohort, single-stage manipulation plus rotator interval and capsular release plus cuff repair produced motion and pain equal to non-stiff repairs by two years, though Constant and ASES scores remained a few points lower [29]. The striking finding was healing: the retear rate was 5.3% in the frozen shoulder group versus 12.3% without (p = .013), plausibly because early motion is limited by the stiffness [29]. Counsel the patient that the first year will be slower and stiffer — 50% versus 39% stiff at one year — but that the tendon is more than twice as likely to be healed [29].

Complications

  • Manipulation: dislocation 0.7% in one 141-patient series [21]; humeral fracture, brachial plexus traction injury, cuff and labral tears reported elsewhere [18]. In UK FROST, 1% of the manipulation arm had a serious adverse event [16].
  • Arthroscopic release: severe complications 2.37% versus 0.51% for manipulation (OR 4.14) [22]; 4% serious adverse event rate in UK FROST, including septic arthritis, anaesthetic events and one likely dislocation [16][22]. Axillary nerve injury is the specific concern with inferior release, and is avoided by staying within about 10 mm of the glenoid rim, working under direct vision, and positioning the arm to displace the nerve [26][27][28].
  • Steroid injection: transient flushing, skin depigmentation, menstrual disturbance, post-injection pain; septic arthritis is rare but reported [16][18].
  • Hydrodilatation: as above, including two joint infections across the pooled series [18].
  • Physiotherapy: no serious adverse events attributable in UK FROST [16]; Cochrane found no difference in adverse events versus injection (RR 1.07) with all events minor [17].
  • Recurrence and contralateral disease: 17% of released patients lose some of the initial gain and 5–10% deteriorate to the point the release is considered unsuccessful [32]. After release, 53% of Smith's patients reported contralateral symptoms at some point and 32% needed treatment for the other shoulder [23].

Recovery and prognosis

Be honest and unhurried. The realistic account is that most people improve substantially, that most of that improvement happens in the first few months and then plateaus, and that a meaningful minority are left with something — 40% with mild to severe symptoms beyond four years by UK FROST's reckoning [16], 41% with ongoing symptoms at a mean 4.4 years in the largest case series [17], and half still reporting pain or stiffness at seven years [6][14].

After release, most of the range is regained early: patients typically reach their final range by 4–6 weeks, and there is little improvement after 12 weeks [25][32]. Return to work in Smith's series was 39% at one week and 69% by three weeks [23]; Galasso's cohort returned to work at a mean of 2.0 months [26].

Post-operative rehabilitation is unstandardised. There are no accepted guidelines, the extent of practice variation has never been documented, and the only comparative trial — 41 patients after hydrodilatation — found no difference between supervised physiotherapy and a home exercise programme [32]. Practice strongly favours starting within 24–48 hours [32]. Willmore's argument is worth weighing: the "hit them quick and hit them hard" philosophy after release "has perhaps been given more credence than it deserved given the evidence base" [32].

Key Evidence

  • [L1] No evidence supports progression through recovery phases to full resolution without treatment; most improvement occurs early, not late, and no study documented an objectively measured return to normal range. [1] (10.1016/j.physio.2016.05.009)
  • [L1] None of early structured physiotherapy with steroid, manipulation, or arthroscopic release was clearly superior at 12 months; manipulation was most cost-effective (£6,984/QALY), release carried the highest risk and cost. [16] (10.3310/hta24710)
  • [L1] Intra-articular corticosteroid was the only intervention to clear both statistical and clinical thresholds for short-term pain and function; the benefit is largely gone by 4–6 months. [15] (10.1001/jamanetworkopen.2020.29581)
  • [L1] Arthroscopic release offers no clinical superiority over manipulation, with a ~4-fold higher odds of severe complication (2.37% vs 0.51%). [22] (10.1111/os.14077)
  • [L1] End-range high-grade mobilisation is no better and no worse than pain-free low-grade mobilisation on any outcome at 6 or 12 months; no trial has compared manual therapy plus exercise against no treatment. [17] (10.1002/14651858.CD011275)
  • [L4] The widely quoted 94% spontaneous recovery figure counts only untreated completers; on an intention-to-treat basis it falls to approximately 26%, and only 51% were fully pain-free at a mean 9 years. [4][1] (10.1007/s11999-011-2176-4)
  • [L1] Genome-wide association implicates five loci; Mendelian randomisation shows type 1 diabetes is causal (OR 1.03) while obesity is not, implying a glycaemic rather than mechanical mechanism. [12] (10.1371/journal.pgen.1009577)
  • [L5] The authors of the consensus definition concede that "sufficient data are not available to confirm" the reliability of the classification; no published study has measured inter-observer agreement on clinical stage. [8] (10.1016/j.jse.2010.07.008)
  • [L1] Adding arthrographic distension to steroid improves short-term pain below the clinical threshold without improving function or rotation; the two hydrodilatation meta-analyses share no studies and disagree on which domain benefits. [15][18][19] (10.1093/bmb/ldad018)
  • [L3] Where a repairable cuff tear coexists with frozen shoulder, single-stage release and repair equalises motion by 2 years and more than halves the retear rate (5.3% vs 12.3%). [29] (10.1177/2325967120934449)
  • [L3] Diabetes predicts the severe biceps–coracohumeral adhesion phenotype (OR 6.97) and worse objective end-range recovery, though several series find no effect on patient-reported outcome. [25][23] (10.1186/s13018-018-0758-5)
  • [L4] Of 168 patients clinically diagnosed with primary frozen shoulder, only 3.0% remained so classified once blood tests and MRI were done; 97% had undiagnosed systemic abnormality and/or intra-articular pathology. [9] (10.5397/cise.2018.21.2.82)
  • [L5] T2 hyperintensity and axillary capsule thickening mark the early stages, but MRI alone cannot completely define the disease stage. [10] (10.1016/j.xrrt.2024.05.002)
  • [L5] The pathology is a ligamentous contracture rather than adhesion or capsulitis; "contracture of the shoulder" has been proposed as the accurate term. [7] (10.1111/j.1758-5740.2009.00007.x)

  • [L5] There are no accepted guidelines for rehabilitation after release, and the only comparative trial found supervised physiotherapy no better than a home programme. [32] (10.1177/1758573220965870)

  • [L3] At a mean 4.4 years, 41% of 269 shoulders still had symptoms; near-normal shoulders predominated only after 3 years, the authors concluding that improvement "then ceases". [34] (10.1016/j.jse.2007.05.009)

See Also

References

[1] Wong CK, Levine WN, Deo K, Kesting RS, Mercer EA, Schram GA, et al. Natural history of frozen shoulder: fact or fiction? A systematic review. Physiotherapy. 2017;103(1):40-7. DOI: 10.1016/j.physio.2016.05.009

[2] Reeves B. The natural history of the frozen shoulder syndrome. Scand J Rheumatol. 1975;4(4):193-6. DOI: 10.3109/03009747509165255

[3] Grey RG. The natural history of "idiopathic" frozen shoulder. J Bone Joint Surg Am. 1978;60(4):564. DOI: 10.2106/00004623-197860040-00029

[4] Vastamäki H, Kettunen J, Vastamäki M. The natural history of idiopathic frozen shoulder: a 2- to 27-year followup study. Clin Orthop Relat Res. 2012;470(4):1133-43. DOI: 10.1007/s11999-011-2176-4

[5] Lubis AMT, Hartanto BR, Kholinne E, Deviandri R. Conservative treatment for idiopathic frozen shoulder: is supervised neglect the answer? A systematic review. Acta Orthop Traumatol Turc. 2022;56(5):340-6. DOI: 10.5152/j.aott.2022.21376

[6] Dias R, Cutts S, Massoud S. Frozen shoulder. BMJ. 2005;331(7530):1453-6. DOI: 10.1136/bmj.331.7530.1453

[7] Bunker T. Time for a new name for frozen shoulder — contracture of the shoulder. Shoulder Elbow. 2009;1(1):4-9. DOI: 10.1111/j.1758-5740.2009.00007.x

[8] Zuckerman JD, Rokito A. Frozen shoulder: a consensus definition. J Shoulder Elbow Surg. 2011;20(2):322-5. DOI: 10.1016/j.jse.2010.07.008

[9] Gwark JY, Gahlot N, Kam M, Park HB. Is the frozen shoulder classification a reliable assessment? Clin Shoulder Elb. 2018;21(2):82-6. DOI: 10.5397/cise.2018.21.2.82

[10] Tamai K, Hamada J, Nagase Y, Morishige M, Naito M, Asai H, et al. Can magnetic resonance imaging distinguish clinical stages of frozen shoulder? A state-of-the-art review. JSES Rev Rep Tech. 2024;4(3):365-70. DOI: 10.1016/j.xrrt.2024.05.002

[11] de la Serna D, Navarro-Ledesma S, Alayón F, López E, Pruimboom L. A comprehensive view of frozen shoulder: a mystery syndrome. Front Med (Lausanne). 2021;8:663703. DOI: 10.3389/fmed.2021.663703

[12] Green HD, Jones A, Evans JP, Wood AR, Beaumont RN, Tyrrell J, et al. A genome-wide association study identifies 5 loci associated with frozen shoulder and implicates diabetes as a causal risk factor. PLoS Genet. 2021;17(6):e1009577. DOI: 10.1371/journal.pgen.1009577

[13] Uppal HS, Evans JP, Smith C. Frozen shoulder: a systematic review of therapeutic options. World J Orthop. 2015;6(2):263-8. DOI: 10.5312/wjo.v6.i2.263

[14] Cho CH, Bae KC, Kim DH. Treatment strategy for frozen shoulder. Clin Orthop Surg. 2019;11(3):249-57. DOI: 10.4055/cios.2019.11.3.249

[15] Challoumas D, Biddle M, McLean M, Millar NL. Comparison of treatments for frozen shoulder: a systematic review and meta-analysis. JAMA Netw Open. 2020;3(12):e2029581. DOI: 10.1001/jamanetworkopen.2020.29581

[16] Brealey S, Northgraves M, Kottam L, Keding A, Corbacho B, Goodchild L, et al. Surgical treatments compared with early structured physiotherapy in secondary care for adults with primary frozen shoulder: the UK FROST three-arm RCT. Health Technol Assess. 2020;24(71):1-162. DOI: 10.3310/hta24710

[17] Page MJ, Green S, Kramer S, Johnston RV, McBain B, Chau M, et al. Manual therapy and exercise for adhesive capsulitis (frozen shoulder). Cochrane Database Syst Rev. 2014;2014(8):CD011275. DOI: 10.1002/14651858.CD011275

[18] Poku D, Hassan R, Migliorini F, Maffulli N. Efficacy of hydrodilatation in frozen shoulder: a systematic review and meta-analysis. Br Med Bull. 2023;147(1):121-47. DOI: 10.1093/bmb/ldad018

[19] Chen T, Li W, Zhong Y, Chen T, Shi X. Efficacy of hydrodistension for frozen shoulder: a systematic review and meta-analysis. Medicine (Baltimore). 2024;103(22):e38388. DOI: 10.1097/MD.0000000000038388

[20] Lin YT, Kuo YC, Wu XN, Liu YF, Hsieh LF. Comparison of the efficacy of ultrasound-guided suprascapular nerve blocks and intraarticular corticosteroid injections for frozen shoulder: a randomized controlled trial. Pain Physician. 2024;27(6):415-24.

[21] Song C, Song C, Li C. Outcome of manipulation under anesthesia with or without intra-articular steroid injection for treating frozen shoulder: a retrospective cohort study. Medicine (Baltimore). 2021;100(13):e23893. DOI: 10.1097/MD.0000000000023893

[22] Zhao Y, Yang T, Feng C, Li L, Pang L, Zhao S. Arthroscopic capsular release versus manipulation under anesthesia for refractory frozen shoulder: a systematic review with meta-analysis. Orthop Surg. 2024;16(7):1517-29. DOI: 10.1111/os.14077

[23] Smith CD, Hamer P, Bunker TD. Arthroscopic capsular release for idiopathic frozen shoulder with intra-articular injection and a controlled manipulation. Ann R Coll Surg Engl. 2014;96(1):55-60. DOI: 10.1308/003588414X13824511650452

[24] Skaliczki G, Kovács K, Antal I, Sallai I, Kovács B, Nyőgér Z, et al. Arthroscopic capsular release is more effective in pain relief than conservative treatment in patients with frozen shoulder. BMC Musculoskelet Disord. 2024;25(1):145. DOI: 10.1186/s12891-024-07275-7

[25] Kanbe K. Clinical outcome of arthroscopic capsular release for frozen shoulder: essential technical points in 255 patients. J Orthop Surg Res. 2018;13(1):56. DOI: 10.1186/s13018-018-0758-5

[26] Galasso O, Mercurio M, Luciano F, Mancuso C, Gasparini G, De Benedetto M, et al. Arthroscopic capsular release for frozen shoulder: when etiology matters. Knee Surg Sports Traumatol Arthrosc. 2023;31(11):5248-54. DOI: 10.1007/s00167-023-07561-2

[27] Ziegenfuss B, Italia K, Stalin KA, Whitehouse S, Gupta A, Cutbush K. The clinical course and outcomes following arthroscopic frozen shoulder 360 release. JSES Int. 2024;8(6):1196-206. DOI: 10.1016/j.jseint.2024.07.006

[28] Chiu CH, Sheu H, Chen P, Berco D, Chan YS, Chen AC. Arthroscopic pan-capsular and transverse humeral ligament release with biceps tenodesis for patients with refractory frozen shoulder. Medicina (Kaunas). 2022;58(12):1712. DOI: 10.3390/medicina58121712

[29] Jeong JY, Shim SB, Hong JH, Im W, Lee SM, Yoo JC. Effect of preoperative frozen shoulder on clinical outcomes after arthroscopic rotator cuff repair. Orthop J Sports Med. 2020;8(7):2325967120934449. DOI: 10.1177/2325967120934449

[30] Paul A, Rajkumar JS, Peter S, Lambert L. Effectiveness of sustained stretching of the inferior capsule in the management of a frozen shoulder. Clin Orthop Relat Res. 2014;472(7):2262-8. DOI: 10.1007/s11999-014-3581-2

[31] Wang L, Yu G, Zhang R, Wu G, He L, Chen Y. Positive effects of neuromuscular exercises on pain and active range of motion in idiopathic frozen shoulder: a randomized controlled trial. BMC Musculoskelet Disord. 2023;24(1):50. DOI: 10.1186/s12891-023-06173-8

[32] Willmore EG, Millar NL, van der Windt D. Post-surgical physiotherapy in frozen shoulder: a review. Shoulder Elbow. 2022;14(4):438-51. DOI: 10.1177/1758573220965870

[33] Nambi G, Alghadier M, Ebrahim EE, Eltayeb MM, Sobeh DE, Aldhafian OR, et al. Efficacy of MRI and clinical findings of lidocaine injection combined with manual therapy in frozen shoulder — a prospective, randomized, single-blinded, sham-controlled trial. PLoS One. 2025;20(8):e0328783. DOI: 10.1371/journal.pone.0328783

[34] Hand C, Clipsham K, Rees JL, Carr AJ. Long-term outcome of frozen shoulder. J Shoulder Elbow Surg. 2008;17(2):231-6. DOI: 10.1016/j.jse.2007.05.009

[35] Liu H, Cai H, Xu J, Jiang Y. Releasing forces in adhesive capsulitis are important indicators of shoulder stiffness and postoperative function. Clin Orthop Relat Res. 2025;483(6):1033-46. DOI: 10.1097/corr.0000000000003365

[36] Sivasubramanian H, Chua CXK, Lim SY, Manohara R, Ng ZWD, Prem Kumar V, et al. Arthroscopic capsular release to treat idiopathic frozen shoulder: how much release is needed? Orthop Traumatol Surg Res. 2021;107(1):102766. DOI: 10.1016/j.otsr.2020.102766

[37] Kim YS, Lee HJ, Park I. Clinical outcomes do not support arthroscopic posterior capsular release in addition to anterior release for shoulder stiffness. Am J Sports Med. 2014;42(5):1143-9. DOI: 10.1177/0363546514523720

[38] Chen J, Chen S, Li Y, Hua Y, Li H. Is the extended release of the inferior glenohumeral ligament necessary for frozen shoulder? Arthroscopy. 2010;26(4):529-35. DOI: 10.1016/j.arthro.2010.02.020

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