Risk in lower limb immobilisation
| Author, date and country | Patient group | Study type (level of evidence) | Outcomes | Key results | Study weaknesses |
|---|---|---|---|---|---|
| Patil et al, 2007, England | 100 ambulatory patients immobilised in lower limb cast for conservatively treated ankle fractures | Prospective observational cohort (level of evidence 2b) | Incidence of DVT on cast removal | 5/100=5% (95% CI 1% to 9%) | 72% patients were fully weight bearing within the plaster. Duration of time in cast ranged from 3 to 7 weeks |
| Testroote et al, 2008, Netherlands | 388 ambulatory non-surgical patients in temporary immobilisation following isolated lower limb injury | Prespecified subgroup analysis within systematic review (level of evidence 2a) | Incidence of DVT in conservatively treated patients | 44/388=11.3% (no CIs provided) | Included studies which excluded those patients at high risk of VTE—likely underestimating incidence. No distinction made between proximal/distal DVT and symptomatic/asymptomatic DVT |
| Nilsson-Helander et al, 2009, Sweden | 100 consecutive patients with acute Achilles tendon rupture, of which half were randomised to conservative non-surgical treatment | Prospective observational cohort (level of evidence 2b) | Colour duplex sonography verified thrombosis in all patients | 32/95=33.7% | Small numbers. Underpowered. Initial thromboprophylaxis for operative patients and then based on surgical preference |
| Colour duplex sonography verified thrombosis in non-surgical patients | 18/46=39.1% | ||||
| PIOPED verified pulmonary embolism in non-surgical patients | 3/46=6.5% | ||||
| Healey et al, 2010, New Zealand | 208 patients with an injury to the tendo Achilles requiring immobilisation in a cast, treated for >1/52 as an outpatient | Retrospective audit to identify patients with Achilles injury, followed by cross-reference with VTE database and retrospective medical record review to identify VTE events | Cumulative symptomatic VTE events within the cohort | 6.3% (95% CI 3.4% to 10.5%) | Patients with follow-up outside district excluded. 20% cohort underwent some form of surgical intervention throughout the study period |
| Confirmed pulmonary embolism within the study period | 1.4% | ||||
| Proximal DVT within the study period | 1.9% | ||||
| Distal DVT within the study period | 2.9% |
DVT, deep vein thrombosis; VTE, venous thromboembolism.