A pilot study was performed to investigate the feasibility of a large randomized controlled trial (RCT) to assess the effects of hyperbaric gaseous cryotherapy (HGC) on the change in knee flexion range of motion in the first two days after total knee arthroplasty.
Background: After total knee arthroplasty (TKA), patients can be discharged from hospital as early as two days after surgery. However, patients often do not achieve functional knee flexion range of motion (ROM) in the first postoperative days. Early application of hyperbaric gaseous cryotherapy (HGC) at the operated knee within an hour after surgery and the next postoperative days might increase ROM by reducing inflammation, edema and pain. However, it is unclear whether such early application of HGC is feasible. Moreover, there is no data to allow calculation of the sample size required to conduct a randomized controlled trial to compare the effects of HGC to those of conventional cryotherapy on the increase of knee flexion in the first two days after TKA. Objectives: To investigate the feasibility of applying HGC within an hour after TKA and twice a day the next postoperative days. To collect data on changes in knee flexion ROM in the first two postoperative days to calculate the sample size required for a large randomized controlled trial. To compare the effects of HGC to those of conventional cryotherapy on changes in knee flexion ROM in the first two postoperative days. Design: A prospective, single-blinded, randomized, controlled pilot trial. Setting: Orthopedic postoperative unit in an acute care hospital. Interventions: Patients were randomly allocated to either hyperbaric gaseous cryotherapy (intervention group) or the ice bag cryotherapy (control group). In each group, participants received the specific cryotherapy intervention at the operated knee within an hour after the surgery (day 0) and twice the next two postoperative days (day 1 and day 2). Outcome measures: Feasibility measures included the rate of eligible patients who were willing to participate, attrition, adherence to interventions and presence of adverse effects. Active and passive knee flexion range of motion (ROM) and knee pain intensity at rest were evaluated on postoperative days 1 and 2. Change in active and passive knee flexion ROM and in knee pain intensity at rest from postoperative day 1 to day 2 were assessed. Length of hospital stay was collected.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
65
In the intervention group, participants received hyperbaric gaseous cryotherapy delivered with a Cryoton ™ device (Cryonic Médical, Salins-les-Bains, France) within an hour after the surgery and two times per day the next postoperative days. The tip of the nozzle was kept 10-15 cm above the dry skin as the gaseous CO2 was sprayed on three zones of 5 cm by 10 cm (medial, lateral and posterior, respectively) using a slow and regular sweeping movement for approximately 30 seconds after a skin temperature of 2°C is reached.
In the control group, participants received two 20-minute treatments of cryotherapy within an hour after the surgery and two times per day the next postoperative days. Cryotherapy was performed using an ice bag that was applied directly on the anterior aspect of the knee. The ice bag is a square latex bag of 30 cm by 30 cm filled with crushed ice and wrapped in a thin pillow case. The treatment assessor applied the intervention in a standardized manner by ensuring that the knee was fully extended while covering the surgical incision and both lateral and medial aspects of the knee with the iced bag.
Changes in active and passive knee flexion ROM measured by analysis.
The primary outcomes were changes in active and passive knee flexion ROM from postoperative day 1 to day 2. This outcome was calculated as the difference in active and passive ROM between day 2 and day 1
Time frame: Between post-operative day 1 and 2
Active and passive knee flexion ROM measured using goniometry.
Active and passive knee flexion ROMs were measured with a long-arm (35 cm) goniometer featuring a 360º and two 180º scales, with 1º increments that read in opposite directions (Baseline 360° 14" Goniometer, Fabrication enterprises Inc., NY, USA). Knee ROMs were measured in sitting position because levels of agreement between observers are higher in sitting position than in supine position.
Time frame: During the first 2 days after surgery.
Knee pain measured by visual analog scale.
Scale from 0 to 10 cm on a ruler where 0 represented no pain and 10 represented the worst pain imaginable.
Time frame: During the first 2 days after surgery.
Change in pain from postoperative day 1 to day 2 measured by analysis of variation of the recorded pain between data of day2 and day 1 (Knee pain measured by visual analog scale)
Calculated as the difference of pain between day 2 and day 1.
Time frame: Between day 1 and 2.
Feasibility was assessed by analysis of presence of adverse effects.
Determine if the patients where having or not adverse during thier stay.
Time frame: Participants will be followed for the duration of hospital stay, an expected average of 3 days.
Feasibility was assessed by adherence to the intervention (attrition).
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Determine if the patients where adhering to treatment (drop-off).
Time frame: Participants will be followed for the duration of hospital stay, an expected average of 3 days.
Length of the stay in hospital ward was measured by the length(in days) of inpatient episode of care.
Length of stay in hospital ward.
Time frame: Participants will be followed for the duration of hospital stay, an expected average of 3 days.