Non-removable plaster cast, removable leg brace or mold that has kept you from moving your leg within the last month

The impact of risk assessment on the implementation of venous thromboembolism prophylaxis in foot and ankle surgery

Nikiforos Pandelis Saragas ¹, Paulo Norberto Faria Ferrao ², Evanthia Saragas ³, Barry F Jacobson ⁴

PMID: 24796824. DOI: 10.1016/j.fas.2013.11.002

Abstract

Background: The purpose of this prospective study was to determine whether the more frequently quoted procedure and patient specific risk factors have any impact in the implementation of venous thromboembolism (VTE) prophylaxis following foot and ankle surgery.

Methods: Two hundred and sixteen patients were included in the study. A variety of operative procedures was carried out with the common denominator being a below knee cast for at least 4 weeks and nonweightbearing for an average of 6 weeks in 130 patients. The remainder of the patients (88) had hallux surgery not requiring a cast and were allowed to weightbear. No patient received any form of thromboprophylaxis postoperatively. All patients were subjected to compression ultrasonography for deep vein thrombosis (DVT) between 2 and 6 weeks postoperatively.

Results: There was a 5.09% incidence of VTE (0.9% pulmonary embolism) overall. As no VTE (neither DVT nor pulmonary embolus) developed in the hallux subgroup, i.e. patients not requiring immobilization and were allowed to weightbear, the incidence of VTE in the cast/nonweightbearing group was 8.46%. The results are descriptive and only statistically analyzed where possible, as the sample size of the VTE group was small. There was no significant difference in number of risk factors and no association between gender in the VTE and non VTE groups. 90.9% of patients in the VTE group had a total risk factor score of 5 or more and 73.7% of patients in the non VTE group had a total risk factor score of 5 or more. The average timing to the diagnosis of VTE in this current study was 33.1 days.

Conclusions: In view of the unacceptable incidence of VTE and the average total risk factor score of 5 or more (for which thromboprophylaxis is recommended) in the majority of the patients, the authors feel that the routine use of thromboprophylaxis in foot and ankle surgery requiring nonweightbearing in combination with short leg cast immobilization, is warranted. This prophylaxis should continue until the patient regains adequate mobility either by weightbearing (in or out of the cast) or removal of cast immobilization (weightbearing or nonweightbearing), usually between 28 and 42 days.

Reference:

Foot Ankle Surg. 2014 Jun;20(2):85-9. doi: 10.1016/j.fas.2013.11.002. Epub 2013 Nov 14.

Pharmacological thromboprophylaxis to prevent venous thromboembolism in patients with temporary lower limb immobilization after injury: systematic review and network meta-analysis

Daniel Horner ^1 2, John W Stevens ², Abdullah Pandor ², Tim Nokes ³, Jonathan Keenan ³, Kerstin de Wit ⁴, Steve Goodacre ²

PMID: 31654551. PMCID: PMC7028118. DOI: 10.1111/jth.14666

Abstract

Background: Thromboprophylaxis has the potential to reduce venous thromboembolism (VTE) following lower limb immobilization resulting from injury.

Objectives: We aimed to estimate the effectiveness of thromboprophylaxis, compare different agents, and identify any factors associated with effectiveness.

Methods: We undertook a systematic review and network meta-analysis (NMA) of randomized trials reporting VTE or bleeding outcomes that compared thromboprophylactic agents with each other or to no pharmacological prophylaxis, for this indication. An NMA was undertaken for each outcome or agent used, and a series of study-level network meta-regressions examined whether population characteristics, type of injury, treatment of injury, or duration of thromboprophylaxis were associated with treatment effect.

Results: Data from 6857 participants across 13 randomized trials showed that, compared with no treatment, low molecular weight heparin (LMWH) reduced the risk of any VTE (odds ratio [OR]: 0.52; 95% credible interval [CrI]: 0.37-0.71), clinically detected deep vein thrombosis (DVT) (OR: 0.39; 95% CrI: 0.12-0.94) and pulmonary embolism (PE) (OR: 0.16; 95% CrI: 0.01-0.74), whereas fondaparinux reduced the risk of any VTE (OR: 0.13; 95% CrI: 0.05-0.30) and clinically detected DVT (OR: 0.10; 95% CrI: 0.01-0.86), with inconclusive results for PE (OR: 0.40; 95% CrI: 0.01-7.53).

Conclusions: Thromboprophylaxis with either fondaparinux or LMWH appears to reduce the odds of both asymptomatic and clinically detected VTE in people with temporary lower limb immobilization following an injury. Treatment effects vary by outcome and are not always conclusive. We were unable to identify any treatment effect modifiers other than thromboprophylactic agent used.

J Thromb Haemost. 2020 Feb;18(2):422-438. doi: 10.1111/jth.14666.Epub 2019 Dec 1.

The effect of ankle joint immobilization on lower limb venous flow

Johnathan D Craik ¹, Amanda Clark ², James Hendry ², Andrea H Sott ², Paul D Hamilton ²

PMID: 25249319. DOI: 10.1177/1071100714552823

Abstract

Background: Below-knee cast immobilization is associated with an increased risk of developing deep vein thrombosis secondary to venous stasis. We investigated the effect of weight-bearing in a below-knee cast or pneumatic walking boot on lower limb venous blood flow.

Methods: Duplex ultrasonography was used to measure venous blood flow in the popliteal vein of 10 healthy volunteers. Venous blood flow was measured while at rest, ambulating non-weight-bearing, partial weight-bearing, and full weight-bearing. Measurements were performed without ankle joint immobilization, with the ankle immobilized in a neutral cast, and with the ankle immobilized in a pneumatic walking boot in both neutral and equinus.

Results: There was no significant reduction in venous blood flow measurements between full weight-bearing without ankle joint immobilization and full weight-bearing in a neutral cast or neutral pneumatic walking boot. However, venous blood flow was reduced when partial weight-bearing (50%) and when full weight-bearing in a pneumatic walking boot in equinus.

Conclusion: These results demonstrate that venous blood flow returned to normal levels when the subjects were permitted to fully bear weight in below-knee casts or walking boots, provided that the ankle joint was not in equinus.

Clinical relevance: Weight-bearing status and ankle joint position should be appreciated during decisions for the provision of chemical thromboprophylaxis.

Reference:

Foot Ankle Int.  2015 Jan;36(1):18-23.

 doi: 10.1177/1071100714552823. Epub 2014 Sep 23.