Table 1

Continuum of rotator cuff pathology, with imaging findings, clinical presentations and management options

State	Underloaded tendon	Normal tendon	Underloaded/normal tendon overload	Reactive tendinopathy (acute phase)	Tendon disrepair (subacute to chronic phase)	Degenerated tendon (chronic phase)
Imaging	Essentially normal tendon	Normal tendon	Oedematous tendon	Oedematous tendon	Oedematous tendon	Neovascularity possible – less likely with an increase in size of tear
	Asymptomatic degeneration and tears may be present	Asymptomatic degeneration and tears may be present	Asymptomatic degeneration and tears may be present	Neovascularity possible	Neovascularity possible	Bursal involvement (evidenced by effusion) possible
	Increasing with age	Increasing with age	Increasing with age	Bursal involvement (evidenced by effusion) possible	Bursal involvement (evidenced by effusion) possible	Large PTT to FTT present involving the rotator cable (may or may not be a cause of pain if present)
				Hypoechoic areas may be present in grey scale (may or may not be cause of pain and symptoms)	Degeneration to small PTT present (may or may not be cause of pain and symptoms)	Fat infiltration may be evident in muscle in CT/MRI
Cause	Suboptimal mechanical stress (stress shielding)	Appropriate mechanical stress	Tendon mechanically overloaded	Tendon mechanically overloaded by surpassing physiological capacity of (1) normal tendon or (2) chronically unloaded tendon	Substantial tendon overload and incomplete healing	Substantial tendon overload and areas of partial- to full-thickness tears
	Increase in MMP1 and MMP13	Normal tensile and compressive properties	May be beneficial or may lead to reactive tendinopathy	No certainty where pain is coming from	No certainty where pain is coming from	No certainty where pain (if present) is coming from
	Due to chronic suboptimal tenocyte stimulation
Clinical	Pain-free and suboptimal shoulder function	Pain-free normal shoulder movement and function	Pain-free shoulder function may be normal or suboptimal	Pain increases with activity	Pain increased with activity	Painful to pain-free shoulder movement
				Persistent pain and night pain suggest bursal involvement	Persistent pain and night pain suggest bursal involvement	Passive movement greater than active movement
Management	Reload tendon in controlled and graduated manner	Maintain physical activity	Reload tendon in controlled and graduated manner	Relative rest Decrease tendon loading by controlling activity level to VAS pain 1.2/10(?)	Reduce pain	Reduce pain
	Increase tendon loading in controlled and graduated manner		Biomechanical unloading interventions Taping(?) Exercise(?)	Relative rest(?) Modalities(?) (US, laser, ESWT, magnetism) Taping(?) Manual therapy(?) Guided injection(?) Response to shoulder symptom assessment procedure(?) GTN patches(?)	Relative rest(?) Modalities(?) (US, laser, ESWT, magnetism) Taping(?) Manual therapy(?) Guided injection(?) Response to shoulder symptom assessment procedure(?) GTN patches(?)
				Reduce pain	Reduce neovascularity	Reduce neovascularity
				Relative rest(?) Modalities(?) (Laser, magnetism) Taping(?) Manual therapy – cervicothoracic spine/upper quadrant(?) Guided analgesic±CS injection(?) (primarily for pain control, CS may decrease cell proliferation and protein production) Response to shoulder symptom assessment procedure(?)	Ice/cryotherapy(?) Heat/thermal modalities(?) Guided sclerosant injections(?) ESWT(?) Exercise (eccentric)(?)	Ice/cryotherapy(?) Heat/thermal modalities(?) Guided sclerosant injections(?) ESWT(?) Exercise (eccentric)(?)
				Reduce swelling Produced by ↑tenocyte activity leading to ↑volume of ground substance. Aggrecan key protein responsible for tendon swelling Ibuprofen – inhibits aggrecan and downregulates cellular response. Has no detrimental effect on tendon repair(?) Ice/cryotherapy(?) – decrease in cell metabolism
				Exercise No high-load elastic or eccentric exercise(?)	Exercise Reload tendon using a supervised graduated exercise programme Control VAS pain to 1–2/10 Eccentric exercise therapy Include manual therapy Include exercise to depress humeral head(?)	Exercise Reload tendon using a supervised graduated exercise programme Control VAS pain to 1–2/10 Eccentric exercise therapy Include manual therapy Include exercise to depress humeral head(?) Specialised exercise programme for large to massive RC tendon tears(?) Stimulation of cellular activity US(?), heat/thermal therapy(?), laser(?), magnetic therapy(?)
				No exercise that involves energy storage and release(?)
				Concentrate on rhythmical arm movements (?) (short lever if required)
				Nutritional supplements/dietary changes(?)	Nutritional supplements/dietary changes(?)	Nutritional supplements/dietary changes(?)
					Surgery Lavage(?) Bursectomy(?) Bursectomy+acromioplasty(?) Repair(?) – important to consider amount of muscular fat infiltration prior to repair	Surgery Lavage(?) Bursectomy(?) Bursectomy+acromioplasty(?) Repair(?) – important to consider amount of muscular fat infiltration prior to repair
				The future Pharmacological modification of cytokines/MMP/TIMP/ADAMTS activity(?)	The future Pharmacological modification of cytokines/MMP/TIMP/ADAMTS activity(?) Stem cells(?) Platelet-rich plasma injections(?)	The future Pharmacological modification of cytokines/MMP/TIMMP/ADAMTS activity(?) Stem cells(?) Platelet-rich plasma injections(?) Tendon grafts(?)The future

ADAMTS, a disintegrin and metalloproteinase with thrombospondin motifs; CS, corticosteroid; ESWT, extracorporeal short-wave therapy; FTT, full-thickness tear; GTN, glyceryl trinitrate; MMP, matrix metalloproteinase;
PTT, partial-thickness tear; RC, rotator cuff; TIMPs, tissue inhibitors of MMP; US, ultrasound; US, therapeutic ultrasound; VAS pain, visual analogue scale for pain; ↓, decrease; ↑, increase; ?, uncertainty – research required.