The effect of active movement of the foot on venous blood flow after total hip replacement

Efficacy and safety of postoperative single-dose anticoagulant treatment in preventing venous thromboembolism after revision hip arthroplasty: a retrospective cohort study

PURPOSE

The purpose of the study is to determine the efficacy and safety of postoperative single-dose anticoagulant treatment in preventing venous thromboembolism (VTE) after revision THA, in comparison with a multiple-dose chemoprophylaxis protocol.

METHODS

We retrospectively compared 295 patients undergoing revision THA who received multiple-dose chemoprophylaxis protocol (40 mg low-molecular-weight heparin once and oral rivaroxaban for 10 days) or single-dose chemoprophylaxis protocol (40 mg low-molecular-weight heparin once) for VTE. The patients in both groups performed active lower limb exercises. Each group was further stratified into subgroups based on the aetiology of revision. The incidence of VTE, wound complications within three months, hidden blood loss (HBL), transfusion rate, and surgical drainage duration were recorded.

RESULTS

The incidence rates of VTE (P = 0.870) did not differ between the two prophylaxis protocols. However, significant differences were observed in wound complications within three months (P = 0.002), HBL (P = 0.015), transfusion rate (P = 0.028). Surgical drainage duration was also shorter in the single-dose chemoprophylaxis group (P = 0.0023). In the subgroup analysis, the use of single-dose chemoprophylaxis protocol cannot significantly reduce HBL and transfusion rate after septic revision THA. The use of multiple-dose chemoprophylaxis protocol (OR = 2.89, P = 0.002) and high BMI (OR = 1.09, P = 0.037) were independent risk factors of wound complications.

CONCLUSIONS

Single-dose chemoprophylaxis protocol effectively and safely prevented VTE after revision THA compared with multiple-dose chemoprophylaxis protocol. The effect in reducing HBL and postoperative transfusion rate was limited in septic revision.

Efficacy of bed exercise in elderly patients after total hip arthroplasty: A retrospective study of 539 patients

The purpose of this study was to observe the necessity of bed exercise therapy in the rehabilitation of elderly patients after hip replacement and to analyze whether bed exercise therapy has an impact on patients' psychological scores, hip function and postoperative complications. From January 2018 to January 2021, a total of 539 patients with end-stage femoral head necrosis or hip osteoarthritis were retrospectively analyzed. According to the method of postoperative rehabilitation exercise, patients were divided into 2 groups: Group A (routine gait) and Group B (bed exercise). There was no significant difference in general information between the 2 groups. There was no significant difference in baseline pain scores between patients in Group A and Group B (25.2 ± 9.6 vs 24.8 ± 10.4, P = .429). However, at 5 weeks post-operatively, the pain scores of patients in Group A were significantly higher than those in Group B (38.6 ± 7.7 vs 34.1 ± 8.1, P = .016). At 17 weeks post-operatively, the difference between Group A and Group B remained (40.9 ± 6.9 vs 37.5 ± 7.5, P = .041). Similar to the pain score, the hip function score compared between the 2 groups was significantly different at 5 weeks (39.7 ± 8.4 in Group A, 45.9 ± 9.2 in Group B, P < .001) and 17 weeks post-operatively (41.5 ± 7.6 in Group A, 47.2 ± 8.8 in Group B, P < .001). At 17 weeks post-operatively, between the 2 groups, only the range of motion (ROM) of abduction showed no significant difference. Patients in Group B exhibited a better ROM in any other movement posture. The results showed that compared with Group A, bed exercise rehabilitation training could reduce the incidence of deep venous thrombosis. This study demonstrates that bed exercise can improve the hip function and quality of life of elderly patients with total hip arthroplasty (THA) at an early postoperative stage. It can reduce the incidence of deep venous thrombosis of the lower limbs after surgery. For these patients, systematic bed exercise rehabilitation training is recommended in the early postoperative period.

A novel device for lower leg intermittent pneumatic compression synchronized with active ankle exercise for prevention of deep vein thrombosis

Objective

Intermittent pneumatic compression devices (IPCDs) and active ankle exercises have been shown to be efficacious in preventing venous thromboembolism (VTE) by increasing venous flow velocity and volume. However, IPCDs are expensive and require electricity; therefore, they cannot be used in the event of power loss. We developed a non-powered device that provides lower leg intermittent pneumatic compression synchronized with AAEs (LISA) and compared its efficacy with AAEs alone in increasing the peak velocity in the femoral vein.

Methods

The study population consisted of 20 healthy younger men and 20 healthy older men who performed AAE every 2 s in a sitting posture under four conditions: AAE with LISA (AAE+LISA), AAE alone (AAE), AAE with IPCD, and AAE with a graduated compression stocking.

Results

The PVs under all conditions were significantly higher than those at rest. The PVs in the AAE+LISA condition were significantly higher than those in the AAE alone condition in both younger and older groups (both p < .001).

Conclusions

AAE with LISA significantly increased the PV, suggesting that LISA might be useful for preventing DVT.

Effects of intermittent pneumatic compression on femoral vein peak venous velocity during active ankle exercise

INTRODUCTION

The risk of developing deep vein thrombosis (DVT) is high even after the period of bed rest following major general surgery including total joint arthroplasty (TJA). Mobile intermittent pneumatic compression (IPC) devices allow the application of IPC during postoperative exercise. Although ambulation included ankle movement, no reports have been made regarding the effects of IPC during exercise, including active ankle exercise (AAE), on venous flow. This study was performed to examine whether using a mobile IPC device can effectively augment the AAE-induced increase in peak velocity (PV).

METHODS

PV was measured by Doppler ultrasonography in the superficial femoral vein at rest, during AAE alone, during IPC alone, and during AAE with IPC in 20 healthy subjects in the sitting position. PV in AAE with IPC was measured with a mobile IPC device during AAE in the strong compression phase. AAE was interrupted from the end of the strong compression phase to minimize lower limb fatigue.

RESULTS

AAE with IPC (76.2 cm/s [95%CI, 69.0-83.4]) resulted in a significant increase in PV compared to either AAE or IPC alone (47.1 cm/s [95%CI, 38.7-55.6], p < 0.001 and 48.1 cm/s [95%CI, 43.7-52.4], p < 0.001, respectively).

DISCUSSION

Reduced calf muscle pump activity due to the decline in ambulation ability reduced venous flow. Therefore, use of a mobile IPC device during postoperative rehabilitation in hospital and activity including self-training in an inpatient ward may promote venous flow compared to postoperative exercise without IPC.

CONCLUSION

Use of a mobile IPC device significantly increased the PV during AAE, and simultaneous AAE with IPC could be useful evidence for the prevention of DVT in clinical settings, including after TJA.

Physical Activity as an Effect Modifier of the Association Between Obesity and Venous Thromboembolism: A Danish Population-Based Cohort Study

Purpose

Obesity is an established risk factor for venous thromboembolism (VTE), while studies on physical inactivity and VTE risk show conflicting results. We examined whether physical activity modified the association between obesity and VTE.

Patients and Methods

We conducted a population-based cohort study by combining data on outcome diagnoses, comorbidities and medication from nationwide registries with self-reported lifestyle data from an extensive Danish lifestyle questionnaire (2001–2015). We computed incidence rates (IRs) and hazard ratios (HRs) of VTE for categories of body mass index (BMI), among the total study population (n=57,523) and for physically active (n=25,387) and inactive individuals (n=30,902) separately.

Results

Obesity (BMI ≥30 kg/m²) was as expected associated with increased VTE risk compared with normal weight (HR 1.62, 95% confidence interval (CI): 1.26–2.09). Independent of BMI category, the rate of VTE was higher for inactive than active individuals. Thus, among obese individuals, the IR per 1000 person-years was 2.03 (95% CI: 1.60–2.57) for inactive and 1.44 (95% CI: 0.97–2.15) for active individuals. In contrast, the HR for VTE comparing obese with normal weight individuals were higher for active (HR 2.19, 95% CI: 1.35–3.58) than inactive individuals (HR 1.36, 95% CI: 1.00–1.84).

Conclusion

Physical activity acts as an effect measure modifier of the association between obesity and VTE. Thus, physical activity reduced the absolute rate of VTE among obese individuals but increased the relative rate of VTE among obese compared with normal weight individuals.

Venous thromboembolism rates after hip and knee arthroplasty and hip fractures

BACKGROUND

The ideal thromboprophylaxis regime following lower limb arthroplasty and proximal femur fractures remains controversial. Guidelines disagree on the type of chemical prophylaxis, its dose or duration. This article describes a method of monitoring venous thromboembolism (VTE) rates following Total Hip (THA), Total Knee Arthroplasty (TKA) and surgery for hip fractures (NOF#).

METHODS

Over 3 years, all patients investigated for VTE were analysed using Picture Archiving Communications System (PACS). All positive scans were then cross-referenced using PACS and local registry data to see if they had undergone THA, TKA or NOF# in the preceding 90 days. Mortality data were obtained from the national administrative database, Hospital Episode Statistics.

RESULTS

Five thousand seven hundred eighty-eight patients underwent investigation for VTE and there were 29 diagnoses of PE and 24 of DVT. There was a 0.77% rate of symptomatic DVT after THA, 0.05% after TKA and 0.55% after NOF #. The rate of confirmed symptomatic PE for THA was 0.46, 0.27% for TKA and 0.96% for NOF #. Mortality at one-year post-THA was 0.6, 0.6% for TKA and 25.9% after NOF#. All patients contacted either remained within the catchment area for the minimum 90 postoperative days or died within the catchment area.

CONCLUSIONS

The 90 day post-operative prevalence of symptomatic VTE of 1.2, 0.3 and 1.5% in THA, TKA and NOF # respectively are similar to other studies using symptomatic and imaging positive VTE as their endpoint. The study uses a method of collecting data which can be utilised in centres where PACS is available.

Effect of resistance of the exercise band on the peak femoral vein velocity during active ankle flexion

Objective

To examine the resistance effect of using an exercise band on the lower extremity venous velocity during active ankle flexion.

Methods

Twenty healthy young adult men performed active ankle flexion every 2 s either with no band or with two exercise bands, marked red and silver in the order of increasing tension. They held the band in its natural length with an elbow in extension and an ankle in maximal dorsiflexion at initiation of each active plantar flexion in each posture. The peak velocity in the right superficial femoral vein was measured in each condition.

Results

Holm’s multiple comparisons revealed significant increases in the mean (individual 95% confidence intervals) peak velocities (cm/s) with no, red, and silver bands (35.8 (28.9–42.7), 46.5 (38.8–54.3), and 56.9 (47.0–66.8), respectively, in the sitting posture, and 50.7 (39.2–62.3), 60.7 (46.8–74.6), and 69.0 (55.3–82.7), respectively, in the supine posture; all p < 0.01).

Conclusion

Resistance with the exercise bands efficiently enhanced the femoral venous velocity during active ankle plantar flexion.

Femoral venous flow velocity during passive ankle exercise in patients with chronic spinal cord injury

[Purpose] We examined the effect of passive ankle exercise on femoral venous flow in paralyzed, atrophied lower legs of patients with chronic spinal cord injury. [Participants and Methods] Ten males with complete spinal cord injury at the T6–12 levels and ten able-bodied males participated in this study. B-mode muscle ultrasound was performed on the medial gastrocnemius muscle to evaluate muscle atrophy. Doppler ultrasound was used to measure the time-averaged mean velocity in the femoral vein at rest and during passive motion of the ankle. [Results] Mean muscle thickness was significantly reduced in the spinal cord injury group, showing a mean value of 67.2% compared with able-bodied participants. No significant differences were observed in the time-averaged mean velocity at rest between the groups, although they were slightly lower in the spinal cord injury group than in the able-bodied group. During passive motion, no significant difference was observed in the time-averaged mean velocity between the groups, although the mean value in those with spinal cord injury was 65.9% that of the able-bodied group. Time-averaged mean velocity increased in both groups, compared with baseline. [Conclusion] Passive ankle exercise increased time-averaged mean velocity in spinal cord injury, but venous blood velocity was reduced in spinal cord injury compared to the able-bodied group. We believe that significant muscle atrophy affected our results in chronic spinal cord injury.

A novel exercise device for venous thromboembolism prophylaxis improves venous flow in bed versus ankle movement exercises in healthy volunteers

PURPOSE

Venous thromboembolism prophylaxis is crucial. To facilitate active ankle movement in postoperative and bedridden patients, we developed a novel leg exercise apparatus (LEX). We investigated the effect of the LEX by comparing increases in lower extremity venous flow during different modes of exercise using the LEX.

METHODS

In eight healthy participants, we measured venous flow volume and velocity in the femoral vein using duplex ultrasonography at 1, 10, 20, and 30 min after completing three modes of 1-min LEX exercises. The exercises involved (1) rapid single motion (ankle dorsi-plantar flexion; 60 cycles/min); (2) slow single motion (30 cycles/min); and (3) slow combined leg motion.

RESULTS

Flow volumes after modes 1, 2, and 3 were 1.63-, 1.39-, and 1.53-fold above baseline at 30 min, respectively. Short periods of rapid single motion, with the LEX, improved postexercise lower extremity venous flow volumes at 30 min and mean venous flow velocity at 20 min, compared to slow single motion exercise. Even at slow speeds, combined-motion improved flow volume compared to single motion.

CONCLUSION

Short periods of rapid single motion exercise, with the LEX, improved postexercise venous flow volumes in the lower extremities at 30 min and mean venous flow velocity at 20 min. These effects were greater than those produced by slow single motion exercises. However, even at slow speeds, combined-motion exercises improved flow volume compared to single motion. Therefore, LEX may prove effective at preventing thromboembolism in postoperative and bedridden patients.

Pilot study evaluating the efficacy of exergaming for the prevention of deep venous thrombosis

OBJECTIVE

Current prophylactic protocols fail to prevent deep venous thrombosis (DVT) in a significant minority of patients, and it remains one of the leading causes of preventable death. We therefore quantified the efficacy of novel game-based exercises (exergaming) to augment femoral venous parameters relative to ankle movement and muscle flexion.

METHODS

Healthy volunteers were recruited to perform a series of ankle and foot exercises using a wireless foot sensor (LEGSys; BioSensics LLC, Watertown, Mass) to navigate a computer cursor sequentially on a screen to the center of 200 circular targets. A single ultrasound technician (W.A.M.) measured each patient's mean flow volume, peak flow velocity, mean flow velocity, and cross-sectional area of the right femoral vein at baseline and obtained immediate postexercise (PEX), 5-minute PEX, and 15-minute PEX measurements. Electromyography (EMG) was performed at baseline and during the exercise. Baseline demographics and medical and surgical comorbidities were also recorded. The primary end point was the difference between baseline and immediate PEX mean flow volume estimates. We secondarily explored the association of baseline characteristics and EMG measurements with femoral vein parameters.

RESULTS

Fifteen healthy subjects (53% male; 28.1 ± 4.6 years) completed the exergaming task within a mean of 4 minutes, 2 ± 21 seconds. Immediately after exercise, the femoral vein mean flow volume, mean velocity, and peak systolic velocity increased by 49%, 53%, and 48%, respectively (P < .02 for each). Mean flow volume and velocity remained significantly elevated 5 minutes after exercise (P < .04 for each). Plantar flexion and dorsiflexion velocities and EMG frequency and intensity were not significantly correlated with PEX mean flow volume estimates (P > .05). Subgroup analysis revealed that women (P < .01) and Hispanics (P < .01) exhibited significantly slower PEX responses. Subjects with the largest improvements in mean flow volume had lower peak plantar flexion velocities (P < .01).

CONCLUSIONS

Exergaming increases mean flow volume, mean flow velocity, and peak systolic velocity within the femoral vein by approximately 50% above baseline. Exergaming represents a novel and potentially attractive method of DVT prevention by augmenting femoral vein mean volume flow and capitalizing on biofeedback. Less forceful but more uniform contractions were found to be most effective at augmenting venous blood flow. Exergaming will require further validation in larger study bases, among patients at higher risk of DVT.

The effect of active toe movement (AToM) on calf pump function and deep vein thrombosis in patients with acute foot and ankle trauma treated with cast - A prospective randomized study

BACKGROUND

Patients with foot and ankle trauma treated with cast are advised to perform toe movements to prevent venous thromboembolism (VTE). Our aim was to determine the effect of active toe movement on asymptomatic deep vein thrombosis (DVT) and venous calf pump function.

METHODS

Patients aged 18-60 years with acute foot and ankle trauma requiring below knee non weight bearing cast were randomized to intervention (regular active toe movement) or control groups (n=100). Patients had bilateral lower limb venous ultrasound to assess for DVT on discharge from clinic. Patients requiring chemical thromboprophylaxis were excluded.

RESULTS

78 completed the study. 27% sustained asymptomatic DVT, with no statistically significant difference in calf pump function or DVT incidence between groups. All DVT's occurred in the injured lower limb.

CONCLUSION

Active toe movement is not a viable strategy for thromboprophylaxis in patients with acute foot and ankle trauma treated with cast.

Intense Triceps Surae Contraction Increases Lower Extremity Venous Blood Flow

Objective

Venous thromboembolism can be prevented by physical prophylaxis, such as active ankle exercise (AAE), in addition to pharmacological treatment. However, the relationship between the intensity of triceps surae (TS) exercise and venous flow is unclear, and physical thromboprophylaxis has not been established for patients with leg cast immobilization. The goals of the current study were to clarify the degree of intensity of TS isotonic contraction required to increase peak blood velocity (PV) in the superficial femoral vein to higher than that at no resistance and to determine if TS isometric contraction can increase PV.

Methods

A prospective, nonrandomized, controlled trial was performed in 20 healthy young adult men. PVs at rest and during one TS isotonic or isometric contraction were measured using Doppler ultrasonography. Isotonic contraction intensity was defined as no resistance with contraction of maximum effort and 25%, 50%, 75%, and 100% of one repetition maximum (1RM). Isometric contraction intensity was defined as 15-35%, 40-60%, 65-85%, and 90-100% of the maximal voluntary contraction.

Results

Isotonic contraction at 75% 1RM (51.4 cm/s [95% CI, 40.1-62.6]) and 100% 1RM (54.9 cm/s [95% CI, 43.1-66.7]) significantly increased PV compared to that with no resistance (41.0 cm/s [95% CI, 32.2-49.8]) (P=0.005, 0.001, respectively). Isometric contraction increased PV significantly at all intensities (all P≤0.002).

Conclusions

Applying resistance at ≥75% 1RM increases venous flow and enhances the effect of AAE with TS isotonic contraction. TS isometric contraction may serve as thromboprophylaxis for patients undergoing leg cast immobilization.

Impact of Active Ankle Movement Frequency on Velocity of Lower Limb Venous Flow following Total Hip Arthroplasty

Background. Although active ankle movement plays a predominant role in mechanical thromboprophylaxis following total hip arthroplasty (THA), the most effective frequency of movement remains unclear. Materials and Methods. In 29 consecutive patients undergoing THA, the velocity of blood flow in the profunda femoris was measured after various frequencies of ankle movement two days after THA using a pulse wave Doppler ultrasound system. To test the interobserver reliabilities for the velocity measured with Doppler ultrasound system, the intraclass correlation coefficient was calculated based on the measurement in 10 limbs of healthy volunteers. Results. At 0, 1, and 2 minutes after ankle movement, the velocity after movement at 60 contractions per minute was significantly faster than that after movement at 40 or 80 contractions per minute (p = 0.0007, repeated-measures analysis of variance). The intraclass correlation coefficient score in two investigators was 0.849 (95% confidence interval, 0.428 to 0.962). Conclusions. Active ankle movement at 60 contractions per minute is recommended in patients receiving THA to obtain optimal venous blood flow.

The use of a novel in-bed active Leg Exercise Apparatus (LEX) for increasing venous blood flow

OBJECTIVE

The incidence of pulmonary embolism (PE) and leg deep vein thrombosis (DVT) has increased in recent years in association with aging and an increase in the number of bedridden individuals. We developed an active in-bed leg exercise apparatus labeled the Leg Exercise Apparatus (LEX) for DVT prevention. We compared the effect of leg exercises performed using the LEX to conventional active ankle exercises on increased blood flow.

MATERIALS & METHODS

The subjects were eight healthy adult volunteers [five men and three women, aged 20-34 (mean 27.0) years]. Subjects performed two types of exercise; exercise 1 consisted of leg exercises using the LEX, while exercise 2 consisted of in-bed active plantar flexion/dorsiflexion exercises without the device. Measurements were taken 1, 5, 10, 20, and 30 minutes after exercise including common femoral vein blood flow, mean blood flow velocity, maximum blood flow velocity, and vessel diameter using Doppler ultrasound. Statistical procedures included timed measurement data analysis using a linear mixed model. A Bonferroni correction was used for multiple comparisons.

RESULTS

Compared to resting levels, blood flow reached a maximum value 1 minute after exercise for both exercise types, with a significantly greater increase after exercise 1 (1.76-fold increase) compared to exercise 2 (1.44-fold increase) (p = 0.005). There was a significant difference (p = 0.03) between the two exercises for all values from 1 minute to 30 minutes following exercise. There was no significant difference between exercises for peak or mean blood flow velocity. Compared to resting levels, blood vessel diameter reached a maximum value of 1.47-fold greater at 5 minutes post-exercise for exercise 1 and a maximum value of 1.21-fold greater at 1 minute post-exercise for exercise 2.

CONCLUSIONS

Exercise using the LEX increased lower leg venous blood flow and vessel diameter. We propose that the LEX may serve as a new DVT prevention tool.

Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

[Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention.

Evaluation of venous return in lower limb by passive ankle exercise performed by PHARAD

This paper presents evaluation of venous return, i.e., blood flow volume of vein (BF), in the lower limb after passive exercise performed by our developed "parallel link type human ankle rehabilitation assistive device (PHARAD)". The PHARAD can perform complex passive exercises (plantar flexion/dorsiflexion, inversion/eversion, adduction/abduction, and combination of these motions) by reproducing input motions of a foot plate that is attached to a sole of foot. The passive exercise can be performed for not only rehabilitation but also prevention of deep vein thrombosis (DVT). In this study, we measured the concentration of Total hemoglobin (Total-Hb) using multi-channel near infra-red spectroscopy (NIRS)-based tissue oximeters and calculated a gradient of Total-Hb during a venous occlusion. We defined the gradient as BF and evaluated BF after 3 min passive exercise performed by the PHARAD comparing to BF of resting. Seven healthy young adult people were recruited for the experiment and we assessed passive exercise, active exercise, and walking. Experimental results show that BF after the passive exercises significantly increases compare to BF of resting and this indicates that passive exercises performed by the PHARAD increases BF and has a potential to prevent DVT.

Passive ankle movement increases cerebral blood oxygenation in the elderly: an experimental study

BACKGROUND

Ankle exercise has been proven to be an effective intervention to increase venous velocity. However, the efficacy of ankle exercise for improving cerebral circulation has not been determined. We hypothesized that ankle exercise in the supine position would be able to increase oxyhemoglobin levels measured at the forehead.

METHODS

Seventeen community-dwelling elderly women participated in this study. We recorded blood pressure, heart rate (HR), and oxyhemoglobin (OxyHb) levels from the participants in the supine position. Participants repeated ankle plantar flexion and dorsiflexion movements for 1 min. Two types of exercise were used: active movement and passive movement. We used two-way analysis of variance to assess the differences in mean arterial blood pressure (MAP), HR, and OxyHb between different exercises (active and passive) and times (before and after exercise).

RESULTS

The HR and MAP increased during active exercise but not during passive exercise. On the other hand, the levels of OxyHb measured at the forehead were elevated during both active and passive exercises. This increase lasted at least 1 min after exercise. There was no significant difference between active and passive exercise with regard to OxyHb; however, a significant difference was observed between before and after exercise (p < 0.05, η(2) G = 0.153).

CONCLUSIONS

The physiological response of OxyHb to ankle exercise was different from that of the other cardiovascular functions. Both active and passive ankle exercises were able to increase cerebral blood oxygenation, whereas the other cardiovascular functions did not respond to passive exercise.

Frequent physical activity may not reduce vascular disease risk as much as moderate activity: large prospective study of women in the United Kingdom

BACKGROUND

Although physical activity has generally been associated with reduced risk of vascular disease, there is limited evidence about the effects of the frequency and duration of various activities on the incidence of particular types of vascular disease.

METHODS AND RESULTS

In 1998, on average, 1.1 million women without prior vascular disease reported their frequency of physical activity and many other personal characteristics. Three years later, they were asked about hours spent walking, cycling, gardening, and housework each week. Women were followed by record linkage to National Health Service cause-specific hospital admissions and death records. Cox regression was used to calculate adjusted relative risks for first vascular events in relation to physical activity. During an average of 9 years follow-up, 49,113 women had a first coronary heart disease event, 17,822 had a first cerebrovascular event, and 14,550 had a first venous thromboembolic event. In comparison with inactive women, those reporting moderate activity had significantly lower risks of all 3 conditions (P<0.001 for each). However, women reporting strenuous physical activity daily had higher risks of coronary heart disease (P=0.002), cerebrovascular disease (P<0.001), and venous thromboembolic events (P<0.001) than those reporting doing such activity 2 to 3 times per week. Risks did not differ between hemorrhagic and ischemic stroke, or between venous thromboembolic events with or without pulmonary embolism.

CONCLUSIONS

Moderate physical activity is associated with a lower risk of coronary heart disease, venous thromboembolic event, and cerebrovascular disease than inactivity. However, among active women, there is little to suggest progressive reductions in risk of vascular diseases with increasing frequency of activity.

Early Mobilization after Free-flap Transfer to the Lower Extremities: Preferential Use of Flow-through Anastomosis

BACKGROUND

Prolonged bed rest and elevation have traditionally been considered necessary after free-flap transfer to the lower extremities. In this retrospective study, we tried to mobilize patients early after free-flap transfer to the lower extremity by means of flow-through anastomosis for both arteries and veins.

METHODS

This study included 13 consecutive patients who underwent immediate free-flap transfer after wide resection of soft-tissue tumors of the lower extremity from March 2012 through July 2013. The defects were above the knee in 5 patients and below the knee in 8 patients. In all patients, flow-through anastomosis was used for both arteries and veins. The patients were mobilized starting on the first postoperative day, and their activities of daily life were gradually expanded, depending on the wound conditions. Postoperative complications and the progression of their activities of daily life were investigated retrospectively.

RESULTS

No anastomotic failure or take back occurred. Partial flap necrosis occurred in 1 patient because of a poor perforator but was unrelated to early mobilization. All patients could move to wheelchairs on the first postoperative day. Within 1 week, 12 of 13 patients could start dangling and 10 of 13 patients could start ambulating.

CONCLUSIONS

This study demonstrates that early mobilization after free-flap transfer to the lower extremity is made possible by flow-through anastomosis for both arteries and veins. Flow-through flaps have stable circulation from the acute phase and can tolerate early dangling and ambulation.

Quantitative index for deciding whether to administer preventive anticoagulant therapy in osteoarthritis patients undergoing total knee arthroplasty

BACKGROUND

The 2008 American Academy of Orthopedic Surgeons recommended that surgeons assess the relative risks of venous thromboembolism and bleeding in patients undergoing total knee arthroplasty (TKA). In this situation, a quantitative index is required for deciding whether to administer preventive anticoagulant therapy for deep venous thrombosis (DVT). In this study, we investigated the risk factors for DVT after TKA.

METHODS

We included 102 patients (122 knees) who underwent primary TKA for osteoarthritis of the knee between October 2007 and March 2010. DVT was evaluated using lower limb venous ultrasonography. Cutoff values for individual risk factors were determined using a receiver-operating characteristic analysis, and the patients were grouped according to the cutoff values; the odds ratios (95% CI) were also investigated. The Wilcoxon signed-rank test and χ² test were also used.

RESULTS

DVT was positive in 25 knees (20.5%). Three risk factors for DVT after TKA were identified: age 76 years or older, preoperative maximum soleus vein (MAX-SV) diameter of 6.0 mm or greater, and preoperative D-dimer value of 1.1 μg/dl or higher. The incidence of DVT was significantly higher in the group with two or more risk factors than in the group with one or no risk factors (p = 0.0001).

CONCLUSIONS

Development of postoperative DVT correlated significantly with the presence of the following risk factors: age 76 years or older, preoperative MAX-SV diameter of 6.0 mm or greater, and a preoperative D-dimer value of 1.1 μg/dl or higher. Considering the risk-benefit ratio, avoiding preventive anticoagulant therapy following TKA can be an option for patients with osteoarthritis with one or no risk factors.

Safety and efficacy of multimodal thromboprophylaxis following total knee arthroplasty: a comparative study of preferential aspirin vs. routine coumadin chemoprophylaxis

Multimodal thromboprophylaxis encompasses preoperative VTE risk stratification, regional anesthesia, mechanical prophylaxis, and early mobilization. We determined if aspirin can be safely used for adjuvant chemoprophylaxis in patients who have a low thromboembolic risk. 1016 consecutive patients undergoing TKA received multimodal thromboprophylaxis. Aspirin was used in 67% of patients and Coumadin 33% (high risk patients, or who were on Coumadin before surgery). This study group was compared to 1001 consecutive patients who received multimodal thromboprophylaxis and routine Coumadin chemoprophylaxis. There was no significant difference in rates of VTE, PE, bleeding, complications, readmission and 90-day mortality between the two groups. There was a significantly higher rate of wound related complications in the control group (p=0.03). Multimodal thromboprophylaxis with aspirin given to the majority of patients at a low VTE risk is safe and effective in patients undergoing primary TKA.

Are current thrombo-embolic prophylaxis guidelines applicable to unicompartmental knee replacement?

Symptomatic and asymptomatic deep-vein thrombosis (DVT) is a common complication of knee replacement, with an incidence of up to 85% in the absence of prophylaxis. National guidelines for thromboprophylaxis in knee replacement are derived from total knee replacement (TKR) data. No guidelines exist specific to unicompartmental knee replacement (UKR). We investigated whether the type of knee arthroplasty (TKR or UKR) was related to the incidence of DVT and discuss the applicability of existing national guidelines for prophylaxis following UKR.

Data were collected prospectively on 3449 knee replacements, including procedure type, tourniquet time, surgeon, patient age, use of drains and gender. These variables were related to the incidence of symptomatic DVT.

The overall DVT rate was 1.6%. The only variable that had an association with DVT was operation type, with TKR having a higher incidence than UKR (2.2% versus 0.3%, p < 0.001). These data show that the incidence of DVT after UKR is both clinically and statistically significantly lower than that after TKR.

TKR and UKR patients have different risk profiles for symptomatic DVT. The risk-benefit ratio for TKR that has been used to produce national guidelines may not be applicable to UKR. Further research is required to establish the most appropriate form of prophylaxis for UKR.

Physical inactivity and idiopathic pulmonary embolism in women: prospective study

OBJECTIVES

To determine the association between physical inactivity (that is, a sedentary lifestyle) and incident idiopathic pulmonary embolism.

DESIGN

Prospective cohort study.

SETTING

Nurses' Health Study.

PARTICIPANTS

69 950 female nurses who completed biennial questionnaires from 1990 to 2008. Main outcome measures The primary outcome was idiopathic pulmonary embolism confirmed in medical records. Multivariable Cox proportional hazards models controlled for age, body mass index (BMI), energy intake, smoking, pack years, race, spouse's educational attainment, parity, menopause, non-aspirin non-steroidal anti-inflammatory drugs, warfarin, multivitamin supplements, hypertension, coronary heart disease, rheumatological disease, and dietary patterns. The primary exposure was physical inactivity, measured in hours of sitting each day. The secondary exposure was physical activity, measured in metabolic equivalents a day.

RESULTS

Over the 18 year study period, there were 268 cases of incident idiopathic pulmonary embolism. There was an association between time of sitting and risk of idiopathic pulmonary embolism (41/104 720 v 16/14 565 cases in most inactive v least inactive in combined data; P<0.001 for trend). The risk of pulmonary embolism was more than twofold in women who spent the most time sitting compared with those who spent the least time sitting (multivariable hazard ratio 2.34, 95% confidence interval 1.30 to 4.20). There was no association between physical activity and pulmonary embolism (P=0.53 for trend).

CONCLUSIONS

Physical inactivity is associated with incident pulmonary embolism in women. Interventions that decrease time sitting could lower the risk of pulmonary embolism.

[What is the interest of early mobilization after total hip arthroplasty? Development of French guidelines for clinical practice]

AIMS

To develop clinical practice guidelines for early mobilisation after total hip replacement (THR).

METHOD

We used the French Society of Physical and Rehabilitation Medicine (Sofmer) methodology, which associates a systematic review of the literature, the collection of information regarding current clinical practice and external review by a multidisciplinary expert panel.

RESULTS

Recommending early mobilisation after THR is not established by a review of the literature. A survey of French clinical practice allows for recommending early mobilisation in the context of complex hip issues. Trials with good methodology must be developed to evaluate the interest of early functional mobilisation corresponding to when patients first stand and take their first steps after surgery. These trials should focus mainly on the final pain, functional status, and reduction of handicap.

[Self-active physical thrombosis prophylaxis in the patients' bed with the Phlebostep: acceptance and measurement of venous blood flow in immobilized patients]

BACKGROUND

Despite the broad use of low molecular weight heparin, deep vein thrombosis is still a relevant risk for immobilized patients in orthopedic surgery. Patients can reduce this risk by active training exercises with a muscle pump. The aim of this study was to test the acceptance and effect of a self-developed training device to accelerate venous return as well as a technical optimization. The device was installed for in-patients in orthopedic and traumatology departments.

PATIENTS AND METHODS

A simple pillow-like device was developed, which can be positioned against the foot end of the patient's bed (Phlebostep). The device gives a sound-based feedback to the patient while pushing actively against it with complete ankle flexion. A digital integrated counter device allows direct feedback to the physician and nursing staff at any time. Initial testing including duplex sonography for venous flow measurements were done on 10 orthopedic in-patients. Prior testing on 7 healthy volunteers was carried out to define the effect of various amounts of pressure on the Phlebostep on the venous blood flow. Additionally, a questionnaire on the general acceptance and user-friendliness was filled out by 84 patients who had used the Phlebostep.

RESULTS

The optimal pressure force was defined as 35 mmHg for further measurements. The venous flow measurements in the 10 postoperative patients revealed an increased venous blood flow in the affected leg by an average of 99.9%. Analysis of the questionnaire from the 84 patients showed a high degree of acceptance.

CONCLUSION

In addition to the technical feasibility, this study showed that use of the Phlebostep resulted on average in a doubling of venous return. The increase of venous flow offers an additional effective device for thrombosis prophylaxis through patient's own active movements and is clearly superior to the use of devices such as antithrombosis stockings alone. The Phlebostep found a high degree of acceptance with the patients.

Simple screening method for deep vein thrombosis by duplex ultrasonography using patients' active maximum ankle dorsiflexion

We hypothesized that venous obstruction by deep vein thrombosis (DVT) only slightly augments venous outflow from lower limbs by active ankle movements. If our hypothesis is true, we thought that we could develop a new screening method for DVT using duplex ultrasonography. Subjects were 22 lower limbs of 11 patients who gave informed consent for venography after total hip or knee arthroplasty. Around postoperative 19.0 days (range 15-32 days), we measured the ratios, called flow ratios, of the peak flow signal with active maximum ankle dorsiflexion and that at rest using duplex ultrasonography in the bilateral femoral veins. On the same day, we then performed bilateral venography. Thrombosis was detected in 5 of the 22 lower limbs. The mean flow ratios with and without DVT were 1.18 (range 1.0-1.3) and 3.31 (range 1.8-4.8), respectively. The flow ratios with DVT were significantly lower than those without DVT. Pain or difficulty performing active maximum ankle dorsiflexion was not observed in any of the operated or unoperated lower limbs during the ultrasound examination. In conclusion, ultrasonographic measurement of flow ratios may become a simple screening method for DVT in lower limbs without the pain or difficulty of performing active maximum ankle dorsiflexion.

Muscle blood flow in response to concentric muscular activity vs passive venous compression

AIM

To measure muscle blood flow (MBF) using photoplethysmography (PPG) following concentric muscular activity of the leg (active treatment) or passive venous compression (passive treatment) with or without venous obstruction.

METHODS

In study A, blood flow in the anterior tibial muscle was measured in 15 healthy subjects with a mean age of 30 years. In study B, blood flow in the gastrocnemius muscle was measured in nine healthy subjects with a mean age of 34 years. Subjects performed concentric muscular activity in one leg. Passive venous compression by a venous foot pump was applied in the contralateral leg.

RESULTS

MBF increased significantly following concentric muscular activity, but not following passive venous compression. MBF decreased in both legs when venous obstruction, induced by a thigh tourniquet, was applied. However, MBF was significantly higher following concentric muscular activity than passive venous compression.

CONCLUSION

We conclude that concentric muscular activity produces higher MBF values than passive venous compression.

A survey of orthopedic surgeons regarding DVT prophylaxis in foot and ankle trauma surgery

This study hypothesized that thromboembolism in patients with foot and ankle trauma is higher than currently recognized, and that prophylaxis varies among surgeons. A questionnaire sent to members of two orthopedic specialty societies surveyed the use of thromboembolic prophylaxis over 1 year. Most did not use preoperative prophylaxis. Postoperatively, 44% of surgeons used prophylaxis, most commonly sequential compression devices and low molecular weight heparin. This survey suggests that thromboembolic prophylaxis is used by < 50% of surgeons treating foot and ankle trauma. The reported cases of thromboembolism in this study underline the need for a prospective investigation.

Effects of ankle exercise combined with deep breathing on blood flow velocity in the femoral vein

Ankle exercises are commonly used to facilitate venous return in the lower extremity and to prevent deep vein thrombosis. Moreover, the respiratory cycle affects venous return. This study examined the effects of ankle exercise combined with deep breathing on the blood flow velocity in the femoral vein. Twenty healthy males (mean age 21.3 years), who had no medical history of lower extremity disease, were recruited for this study. The blood flow velocity in the femoral vein was measured while performing four exercise protocols: quiet breathing while resting (QR), deep breathing (DB), ankle exercise with quiet breathing (AQB), and ankle exercising combined with deep breathing (ADB). Using a Doppler ultrasound with an 8 MHz probe, peak blood flow velocities were collected for a 20 second period at the start of the inspiration phase in each protocol, three times. There were statistically significant differences in the peak blood flow velocity in the femoral vein with the four protocols (p lt 0.001). The mean (SD) peak blood flow velocity in the femoral vein was as follows: QR 10.1 (4.2) cm/sec, DB 15.5 (3.9) cm/sec, AQB 20.7 (6.6) cm/sec, and ADB 26.5 (9.4) cm/sec. Post hoc analyses revealed significant differences between each of the four protocols (p(adj) lt 0.01). The mean peak blood flow velocity in the femoral vein was greatest with the ADB protocol, which implies that the ADB protocol may be useful to prevent the blood stasis in patients at risk of deep vein thrombosis.

Effect of manual lymph drainage after hindfoot operations

BACKGROUND AND PURPOSE

Manual lymph drainage therapy is often prescribed following hindfoot operations. However, the relative efficacy of this treatment component has not yet been determined.

METHOD

A two-group pre-test-post-test study design was used in this preliminary randomized clinical trial of 23 subjects who underwent hindfoot surgery. Patients were randomly assigned into two groups: an intervention group of 11 patients who received standard physiotherapy plus manual lymph drainage; and a control group of 12 patients who received standard physiotherapy but no lymph drainage. The main outcome measure was the percentage reduction in excess limb volume, measured by the water displacement method at the second post-operative day (t1) and at the day of discharge (t2).

RESULTS

Compared to the control group, a significant reduction in post-operative swelling was measured in the intervention group only (p = 0.011).

CONCLUSIONS

Application of lymph drainage techniques after hindfoot operations, in combination with standard physiotherapy exercises, achieves greater limb volume reduction than exercise alone. The present study offers an insight into a treatment that may shorten rehabilitation and thereby control the cost of caring for post-operative treatment complicated by post-operative swelling.

Altered venous function and deep venous thrombosis following proximal femoral fracture

The effect of surgery for femoral neck fracture on lower limb venous blood flow and its relationship to deep vein thrombosis was investigated in 179 patients. Blood flow was measured using strain gauge plethysmography before surgery, in the 1st week after surgery, and at 6 week review. There was a significant reduction in both venous outflow and venous capacitance, affecting both fractured and non-fractured legs but significantly greater in the fractured leg. Venous function remained significantly impaired in both lower limbs 6 weeks after surgery. There was a significant correlation between the reduction in venous function and the development of deep vein thrombosis.

Late occurring clinical deep vein thrombosis in joint-operated patients

In a prospective study of 4,840 patients, we determined the annual incidence of clinical deep vein thrombosis (DVT) in mobilized, discharged orthopedic-operated "high-risk" patients (hip replacement surgery, knee replacement surgery, nailed hip fracture) and assumed "low-risk" patients (diagnostic knee arthroscopy). In addition, the time from the operation to the time when the patients were readmitted with clinically suspected DVT and the distribution of radiologically-confirmed DVT were recorded. Thromboprophylaxis was routinely given for about 10 days to the high-risk groups during the hospital stay but not to patients undergoing knee arthroscopy. During 9 years, the annual incidence of DVT following major procedures was 2.1% (95% CI 1.6-2.6) vs. 0.6% (95% CI 0.2-1.1) after diagnostic knee arthroscopy. Symptoms appeared, on average, 27 (3-150) days after total hip replacement surgery, 36 (3-150) days after nailed hip fracture, 17 (6-30) days after total knee replacement and 1 (1-6) day after knee arthroscopy. In hip-operated patients, 50% of the DVTs were found in the proximal veins vs. 40% following knee arthroplasty.

Thromboprophylaxis in hip arthroplasty. New frontiers and future strategy

Coagulation-related complications are a frequent cause of death following hip replacement surgery. Venographically-proven deep vein thrombosis (DVT) is found in a high frequency. Most cases have no symptoms. Fatal pulmonary embolism (PE) may develop from subclinical thrombi. In addition, arterial thromboses may induce serious cardiovascular events and an unknown number of patients may develop cardiorespiratory insufficiency, due to non-fatal venous PE. Finally, several patients may develop venous insufficiency. Recent prospective double-blind studies have shown that the frequency of deep vein thrombosis increased after hospital discharge in patients undergoing hip replacement surgery. Prolonged thrombo-prophylaxis with low-molecular-weight heparin (dalteparin or enoxaparin) is recommended for at least 5 weeks after the operation.