Methods

Design: Randomized trial.
Method of randomization: 121 patients were randomly allocated in the order in which they had been hospitalized.
Method of allocation: 121 patients were randomly allocated in the order in which they had been hospitalized.
Blinding of outcomes assessors: Not described.

Participants

Source population: Not described.
Sample size:
The calf‐thigh pump group: 58,
The plantar pump group: 63.
Subject selection:
Inclusion: Patients who had undergone THA.
Exclusion: Patients with a history of DVT, pulmonary embolism, congestive heart failure, venous insufficiency, or the presence of a malignant tumor.
Mean age:
The calf‐thigh pump group: 61.36,
The plantar pump group: 62.21.
Gender (%):
Males: 18, females: 103.
The calf‐thigh pump group: 86.2% female,
The plantar pump group: 84.1% female.

Interventions

Type of IPC devices used:

The calf‐thigh pump group: Medomer Automatic Air Massager (Nitto Kohki, Tokyo, Japan),
The plantar pump group: A‐V impulse system (Orthofix Vascular Novamedix, Andover, UK).
Interventions: Immediately after the operation, all patients were fitted with either a plantar pump or a calf‐thigh pump. The fitting time for both groups was 4 hours per day over a period of 21 days in all patients. No anticoagulant drugs or antiembolism stockings were used.

Outcomes

Outcomes included in this review:

1. Symptomatic DVT or PE;

2. Edema.

Other outcomes: D‐dimer level.

Notes

The edema was evaluated by the changes in the circumference of the thigh and lower leg. The circumferences of the thigh and the lower leg were measured at 6 a.m. on the day of the operation and again at the same time on days three, seven, 14 and 21 postoperatively. The postoperative measurements were compared to the preoperative measurements, taken as 100%.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

High risk

121 patients who had undergone THA were randomly allocated in the order in which they had been hospitalized.

Allocation concealment (selection bias)

High risk

121 patients who had undergone THA were randomly allocated in the order in which they had been hospitalized.

Blinding of participants and personnel (performance bias)
All outcomes

High risk

Complete blinding of treatment is impossible for patients and investigators.

Blinding of outcome assessment (detection bias)
All outcomes

High risk

There is no evidence that outcome assessors were blinded during the conduct and analysis of the study.

Incomplete outcome data (attrition bias)
All outcomes

High risk

The increased ratio of the circumference of the thigh and the lower leg were shown by figures and the standard deviations were not provided.

Selective reporting (reporting bias)

Unclear risk

No description of the protocol was registered.

Other bias

Low risk

The two study groups were matched with regard to gender, age, leg operated on, duration of the operation, and body mass index.