Table A2

Risk in lower limb immobilisation

Author, date and countryPatient groupStudy type (level of evidence)OutcomesKey resultsStudy weaknesses
Patil et al, 2007, England100 ambulatory patients immobilised in lower limb cast for conservatively treated ankle fracturesProspective observational cohort (level of evidence 2b)Incidence of DVT on cast removal5/100=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, Netherlands388 ambulatory non-surgical patients in temporary immobilisation following isolated lower limb injuryPrespecified subgroup analysis within systematic review (level of evidence 2a)Incidence of DVT in conservatively treated patients44/388=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, Sweden100 consecutive patients with acute Achilles tendon rupture, of which half were randomised to conservative non-surgical treatmentProspective observational cohort (level of evidence 2b)Colour duplex sonography verified thrombosis in all patients32/95=33.7%Small numbers. Underpowered. Initial thromboprophylaxis for operative patients and then based on surgical preference
Colour duplex sonography verified thrombosis in non-surgical patients18/46=39.1%
PIOPED verified pulmonary embolism in non-surgical patients3/46=6.5%
Healey et al, 2010, New Zealand208 patients with an injury to the tendo Achilles requiring immobilisation in a cast, treated for >1/52 as an outpatientRetrospective audit to identify patients with Achilles injury, followed by cross-reference with VTE database and retrospective medical record review to identify VTE eventsCumulative symptomatic VTE events within the cohort6.3% (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 period1.4%
Proximal DVT within the study period1.9%
Distal DVT within the study period2.9%
  • DVT, deep vein thrombosis; VTE, venous thromboembolism.