Hemostatic parameters in patients with spinal cord injury in subacute and chronic phase of the rehabilitation.

Objective: The goal of this study was to measure hemostatic markers after SCI.Design: Assesing changes in coagulation and fibrynilitic system in SCI patients in different time post injury to Cross-sectional study.Setting: Rehabilitation Department of the Bydgoszcz University Hospital, Poland from 2011 to 2017.Participants: SCI patient during acute and chronic rehabilitation (N = 88).Outcome Measures: Assesing following parameters: platelet counts and levels of D-dimer, antithrombin III (ATIII), tissue factor (TF), tissue factor pathway inhibitor (TFPI) and the inflammatory marker, C-reactive protein (CRP).Interventions: Eighty-eight SCI patients were divided into three groups based on the time elapsed from injury: group I (three weeks to three months), group II (three to twelve months) and group III (more than twelve months). All patients underwent ultrasonography (US) to detect acute or chronic recanalized deep vein thrombosis (DVT). Platelet counts and levels of D-dimer, ATIII, TF, TFPI and CRP were assessed. TF and TFPI levels were measured in the control group of forty healthy individuals without SCI, the rest of the parameters were compared to laboratory norms.Results: D-dimer levels were significantly higher in group I compared to group II (P = .0002) and group III (P < .001). Group II had higher D-dimer levels than group III (P = .032). TFPI levels were higher in group II compared with group III (P = .0041) and control group (P = .000033). TF was significantly higher in all the SCI groups compared with the control group (P < .001).Conclusions: D-dimer and TF levels were still elevated twelve months after SCI. TF levels were also elevated over 12 months after inury. The results may indicate that sub-acute and even chronic SCI patients have disturbed coagulation and fibrynolitic system.

Prospective evaluation of muscle strength and spine joint motility of patients who underwent surgery for colorectal cancer by open and laparoscopic methods.

INTRODUCTION: The current trend in oncological surgery is to minimize its degree of invasiveness while maintaining a satisfactory survival rate. Surgical treatments within the large intestine are applied through traditional open surgery (OS) or laparoscopic surgery (LS). AIM: The purpose of this nonrandomized, prospective, single-centered clinical examination was to compare motility within the spine joints and evaluate abdominal muscle strength of patients who underwent LS or OS for colorectal cancer. MATERIAL AND METHODS: Seventy-two patients were included in the study. Open surgery was applied to 35 patients and LS was applied to 37 patients. Motility range of the thoracic and lumbar spine, muscle strength of abdominal muscles, and pain evaluation by the Visual Analogue Scale (VAS) of the studied group were evaluated twice (on the day of admission to the ward and on the fifth day after the surgery). RESULTS: Both types of surgical intervention resulted in a decrease of the rectus abdominis and abdominal oblique muscle strength as well as a decrease of the range of thoracic and lumbar spine joint motility (p < 0.001). In the first research period, no statistically significant differences of tested parameters between the groups were found. In the second period, patients who underwent LS achieved better results within the extension of lumbar spine section (p = 0.0339), rectus abdominis strength (p = 0.0105), and left abdominal oblique muscles (p = 0.004). CONCLUSIONS: Both types of surgical intervention (LS and OS) result in reduction of spine joint motility range and abdominal muscle strength. Laparoscopic surgery disrupts the spine joint motility and abdominal muscle strength to a lesser extent than OS.

Modulatory effect of laser irradiation on mastoparan-7-induced contraction.

Mastoparan-7 activates guanine nucleotide-binding proteins (G-proteins) and stimulates both apoptosis and increases in cytoplasmic calcium concentration and may induce smooth muscle contraction. The primary aim of the present study was to evaluate the modulatory effect of laser stimulation on vascular smooth muscle contraction induced by direct stimulation of G-protein with mastoparan-7. Experiments were performed on isolated and perfused tail arteries of Wistar rats. Contraction force in the model was measured by increased levels of perfusion pressure with a constant flow. Irradiation treatment was applied directly to the blood vessels. The laser was applied in increasing doses of 10 mW (E=1.8 J), 30 mW (E=5.5 J) and 110 mW (E=19.8 J). Time of exposure was 3 min for each irradiation. In the laser-stimulated arteries, a significant and dose-dependent decrease was observed. The half maximal effective concentration values were 4.43±2.2x10-8, 2.4±0.56x10-7, 3.2±0.72x10-7 and 7.7±0.3x10-7 M/l in the control and 10, 30 and 110 mW laser irradiation groups, respectively. Significant (P<0.001) changes were identified for all laser treatment groups in comparison with the control. When analyzing the function of calcium ion (Ca2+) stores was analyzed, a significant inhibition of influx from both intra- and extracellular Ca2+ stores was observed. The results from the present study suggested that contraction induced by direct activation of G-protein with mastoparan-7 may by effectively inhibited by laser radiation, and that the effect was associated with an inhibition of Ca2+ influx from both intracellular and extracellular Ca2+ stores.

Prospective evaluation of the quality of life of patients undergoing surgery for colorectal cancer depending on the surgical technique.

PURPOSE: Monitoring of the quality of life of patients in addition to satisfactory survival indexes in order to choose an optimal treatment method is a trend in contemporary oncological surgery. The goal of the study was to prospectively evaluate the quality of life of patients treated for colorectal cancer depending on the type of surgical technique (open surgery (OS) vs. laparoscopic surgery (LS)). METHODS: The quality of life was evaluated thrice in the study groups (on the day of admission to the ward (I), 6 months (II), and 18 months after the procedure (III)). The following questionnaires were used in this evaluation: QLQ-C30 European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, QLQ-CR29 Quality of Life Questionnaire (module-colorectal cancer), and Acceptance of Illness Scale (AIS). RESULTS: Sixty-seven patients completed this prospective clinical cohort study (LS-32; OS-35). The QLQ-C30 questionnaire demonstrated improvement in functional scales among patients treated with LS technique (p < 0.05) as well as with regard to overall quality of life 6 months after surgery (p < 0,001), while at 18 months postsurgery, statistically significant differences were noted for physical function (p = 0.001) and overall quality of life (p < 0.0001). AIS scale analysis demonstrated that patients treated with laparoscopy were characterized by better acceptance of illness (p < 0.05). Statistically significant differences between OS and LS groups were noted based on the QLQ-CR29 questionnaire with regard to the following scales: body image (p = 0.041) and body mass problem (p = 0.024)-patients treated with LS technique had better scores. CONCLUSIONS: Laparoscopic surgery gives patients a chance for better quality of life.

Ultrasound therapy: Dose-dependent effects in LBP treatment.

BACKGROUND: Low back pain (LBP) affects most people at least once in their lives. OBJECTIVE: To evaluate the efficacy of ultrasound therapy (UD) in patients with LBP receiving two different treatment dosages. METHODS: The study design was a randomized prospective study. Patients were subjected to UD for two weeks. All persons in the study were evaluated at the Outpatient Rehabilitation Clinic at the Antoni Jurasz University Hospital in Bydgoszcz, Poland. Inclusion criteria were lumbosacral pain lasting more than 8 weeks, signs of osteoarthritis on imaging studies, and ages30-65 years. Exclusion criteria were radicular pain, nonmechanical causes of pain, contraindications for UD, or the patient received other LBP therapy during the study. The Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RM), and Visual Analog Scale (VAS) were used to evaluate the results. RESULTS: For both groups, the ODI scores were significantly reduced by 13.7% and 8.84%, the RM scores decreased by 3.37 points and 3.59 points, and pain remissions on the VAS scale were 20.28 mm and 16.31 mm (p< 0.05). CONCLUSION: UD decreased patients' disability levels and pain intensity. However, effective ultrasound parameters must be determined because of the wide dosage variations.

Assessment of quality of life in women five years after breast cancer surgery, members of Breast Cancer Self-Help Groups - non-randomized, cross-sectional study.

AIM OF THE STUDY: To assess the quality of life in patients treated for breast cancer who were 5 years after diagnosis and were active members of Breast Cancer Self-Help Groups. MATERIAL AND METHODS: The study had a non-randomized, cross-sectional design. We enrolled 167 women who were more than 5 years after mastectomy and were active members of Breast Cancer Self-Help Groups (group A1). As a control group we enrolled 117 women after mastectomy - not members of such support groups (group A2). For the evaluation of the quality of life in both groups we used the following standardized questionnaires - EORTC QLQ-C30 and EORTC QLQ-BR23 as well the Mini-MAC scale for the assessment of strategies of coping with disease. RESULTS: Based on QLQ C30 scores, group A1 had better emotional functioning (p = 0.0005) and a higher general quality of life (p = 0.0259), whereas group A2 had better role functioning (p = 0.0042). Based on QLQ BR23 scores, there were statistically significant differences in body image (p = 0.0366) and life perspectives (p = 0.0313) in favor of group A1. In the control group, there was a greater use of destructive coping strategies and anxious preoccupation (p = 0.1957). CONCLUSIONS: Membership in Amazon groups improves functioning in breast cancer patients that can also extend into a five-year period after treatment completion.

Foot posture in female patients 5 years after breast-conserving surgery: a case-control study.

PURPOSE: Along with the improvement in the outcomes of breast cancer treatment being observed in the recent years, long-term studies to assess distant adverse effects of the treatment have become increasingly important. The objective of this study was to assess the foot posture in patients subjected to breast-conserving therapy. The assessment was made 5 years after the surgical procedure. METHODS: 116 female patients (mean age of 58.75 years) were qualified into a case-control study. Foot posture on the operated breast side (F1) as well as on the contralateral side (F2) was evaluated using a computer-based foot analysis tool as an extension of projection moiré-based podoscopic examination. Comparisons were made for the following parameters: limb load, L-foot length, W-foot width, L/W-Wejsflog index, ALPHA-hallux valgus angle, BETA-little toe varus angle, GAMMA-heel angle, KY-Sztriter-Godunov index, CL-Clarke's angle, HW-heel width. RESULTS: Five years after BCT, patients placed higher load on the foot on the side of the healthy breast (p = 0.0011). No statistically significant differences were observed between F1 and F2 with respect to other foot posture parameters (p > 0.05). No statistically significant differences were observed in foot posture parameters in patients having undergone BCT + ALND (axillary lymph node dissection) procedure as compared to patients subjected to BCT + SLNB (sentinel lymph node biopsy) procedure (p > 0.05). CONCLUSIONS: No changes in foot posture were observed in patients 5 years after the BCT procedure. The type of the surgical procedure related to the lymph nodes within the axillary fossa has no effect on changes in foot posture.

Analysis of Undesirable Sequelae of Sentinel Node Surgery in Breast Cancer Patients - a Prospective Cohort Study.

Use of sentinel lymph node biopsy limits the frequency and severity of sequelae of surgical treatment. However, the procedure itself may not be completely free of complications. The goal of this work was to analyze prospectively the occurrence of undesirable sequelae in patients undergoing sentinel lymph node biopsy as an isolated intervention in the axillary fossa. This prospective observational study was conducted on a group of 104 women. Patients were examined on five occasions: one day before the procedure, one day after the procedure, one month, three months, and six months after the procedure. At every stage of the study they were assessed for tactile sensation, range of motion in the shoulder joint, upper limb circumference, sensation abnormalities, winged scapula sign, and pain severity according to Visual Analogue Scale (VAS). In the study group we observed statistically significant differences, such as limited mobility in the shoulder joint (p ≤ 0.01), gradual increase in limb circumference on the operated side (p < 0.01) and pain (p ≤ 0.01). Despite relatively low invasiveness of the procedure, sentinel lymph node biopsy is not entirely devoid of the risk of undesirable sequelae.

The influence of low level laser irradiation on vascular reactivity.

PURPOSE: The mechanism of action of low level laser irradiation on tissues is unclear. Authors of publications present the positive clinical impact of low and medium power laser irradiation on vascular reactivity. The purpose of this study was to analyze the role of vascular endothelium in laser-induced constricted by endothelin-1 and phenylephrine. MATERIALS AND METHODS: Experiments were performed on isolated and perfused rat tail arteries of weighing 250-350g male Wistar rats. Contractility of arteries as a response to endothelin-1 and phenylephrine was measured after exposure to laser stimulation (10, 30 and 110mW). RESULTS: Laser irradiation inhibits vascular smooth muscle contraction induced by endothelin-1 and an alpha-adrenergic receptor agonist, phenylephrine proportionally to the laser power. Concentration-response curves were shifted to the right with significant reduction in maximal response. Laser irradiation at the power of 10mW, 30mW, and 110mW reduced the maximum response of arteries stimulated with phenylephrine sequentially to 88%, 72%, and 52%. Similar findings were observed during stimulation of endothelin-1. Laser irradiation at the power of 10mW, 30mW and 110mW resulted in maximal response respectively reduced to 94%, 62% and 38%. CONCLUSION: Our results strongly suggest that during low level laser irradiation vascular smooth muscle cells reactivity is reduced, this effect is present in arteries with normal endothelium. The mechanism of action of laser biosimulation on tissues is unclear. Authors of publications present the positive clinical impact of low level laser irradiation on vascular reactivity.

Evaluation of distant sequelae of breast cancer treatment among patients after breast-conserving surgery depending on the type of intervention in the axillary fossa.

AIM OF THE STUDY: The goal of this work was to assess upper-limb sequelae among patients undergoing breast-conserving therapy (BCT) for breast cancer 5-6 years after the surgical procedure. MATERIAL AND METHODS: A controlled clinical study was conducted on 128 patients who had undergone surgery 5-6 years prior. BCT + ALND (axillary lymph node dissection) was performed in 58 patients and 69 underwent BCT + SLND (sentinel lymph node dissection). Patients declared active participation in physiotherapy. The following parameters were assessed in studied subjects: range of motion in the shoulder joint, superficial sensation, upper limb circumference, skin sensation, and presence of winged scapula sign. RESULTS: Five to six years after BCT, patients who had undergone BCT + ALND presented with significantly poorer outcomes concerning upper limb range of motion on the operated side compared to the BCT + SLND group with regard to the following features: flexion (p = 0.00004), external rotation (p = 0.0292), and internal rotation (p = 0.0448). However, no statistically significant differences were noted between compared groups with regard to upper limb circumference and sensation disturbances. Statistically significant differences between limb on the operated side (operated limb - OL) vs. contralateral limb (healthy limb - HL) were noted in the BCT + SLND group with regard to the range of motion in extension (p = 0.0004), external rotation (p = 0.0055), and internal rotation (p < 0.0001), as well as the occurrence of winged scapula sign (p < 0.0001) and sensation disturbances (p < 0.0001). CONCLUSIONS: Our study demonstrated that both procedures are not free of distant sequelae, although the BCT + ALND group is more frequently affected.

Evaluation of changes to foot shape in females 5 years after mastectomy: a case-control study.

PURPOSE: The aim of this study was to evaluate changes in foot shape of women 5 years after undergoing breast amputation. METHODS: Evaluation of foot shape was performed using a non-invasive device for computer analysis of the plantar surface of the foot. Obtained results were compared between feet on the healthy breast side (F1) and on the amputated breast side (F2). RESULTS: 128 women aged 63.60 ± 8.83, 5-6 years after breast amputation were enrolled in this case-control study. Weight bearing on the lower extremity on the amputated breast side (F1) compared with the healthy breast side (F2) showed statistically significant differences (p < 0.01). Patients put more weight onto the healthy breast side. No statistically significant difference was found with regard to F1 and F2 foot length (p = 0.4239), as well as BETA (p = 0.4470) and GAMMA (p = 0.4566) angles. Highly statistically significant differences were noted with respect to foot width, ALPHA angle, and Sztriter-Godunov index-higher values were observed on the healthy breast side (p < 0.001). Highly statistically significant differences were also noted while comparing Clark's angles, higher values being observed on the operated breast side (p < 0.001). CONCLUSIONS: Differences in foot shape on the healthy breast side and amputated breast side constitute a long-term negative consequence of mastectomy, and can be caused by unbalanced weight put on feet on the healthy breast side compared to the amputated breast side.

Systematic review and meta-analysis of randomized controlled trials assessing safety and efficacy of posterior pericardial drainage in patients undergoing heart surgery.

OBJECTIVES: To investigate the potential beneficial effects of posterior pericardial drainage in patients undergoing heart surgery. METHODS: Multiple online databases and relevant congress proceedings were screened for randomized controlled trials assessing the efficacy and safety of posterior pericardial drainage, defined as posterior pericardiotomy incision, chest tube to posterior pericardium, or both. Primary endpoint was in-hospital/30 days' cardiac tamponade. Secondary endpoints comprised death or cardiac arrest, early and late pericardial effusion, postoperative atrial fibrillation (POAF), acute kidney injury, pulmonary complications, and length of hospital stay. RESULTS: Nineteen randomized controlled trials that enrolled 3425 patients were included. Posterior pericardial drainage was associated with a significant 90% reduction of the odds of cardiac tamponade compared with the control group: odds ratio (95% confidence interval) 0.13 (0.07-0.25); P < .001. The corresponding event rates were 0.42% versus 4.95%. The odds of early and late pericardial effusion were reduced significantly in the intervention arm: 0.20 (0.11-0.36); P < .001 and 0.05 (0.02-0.10); P < .001, respectively. Posterior pericardial drainage significantly reduced the odds of POAF by 58% (P < .001) and was associated with significantly shortened (by nearly 1 day) overall length of hospital stay (P < .001). Reductions in postoperative complications translated into significantly reduced odds of death or cardiac arrest (P = .03) and numerically lower odds of acute kidney injury (P = .08). CONCLUSIONS: Posterior pericardial drainage is safe and simple technique that significantly reduces not only the prevalence of early pericardial effusion and POAF but also late pericardial effusion and cardiac tamponade. These benefits, in turn, translate into improved survival after heart surgery.

The Effect of Two Different Cognitive Tests on Gait Parameters during Dual Tasks in Healthy Postmenopausal Women.

INTRODUCTION: The paper aims to evaluate the influence of two different demanding cognitive tasks on gait parameters using BTS SMART system analysis. PATIENTS AND METHODS: The study comprised 53 postmenopausal women aged 64.5 ± 6.7 years (range: 47-79). For every subject, gait analysis using a BTS SMART system was performed in a dual-task study design under three conditions: (I) while walking only (single task), (II) walking while performing a simultaneous simple cognitive task (SCT) (dual task), and (III) walking while performing a simultaneous complex cognitive task (CCT) (dual task). Time-space parameters of gait pertaining to the length of a single support phase, double support phase, gait speed, step length, step width, and leg swing speed were analyzed. RESULTS: Performance of cognitive tests during gait resulted in a statistically significant prolongation of the left (by 7%) and right (by 7%) foot gait cycle, shortening of the length of steps made with the right extremity (by 4%), reduction of speed of swings made with the left (by 11%) and right (by 8%) extremity, and reduction in gait speed (by 6%). CONCLUSIONS: Performance of cognitive tests during gait changes its individual pattern in relation to the level of the difficulty of the task.

The Assessment of the Magnitude of Frontal Plane Postural Changes in Breast Cancer Patients After Breast-Conserving Therapy or Mastectomy - Follow-up Results 1 Year After the Surgical Procedure.

Breast cancer is the most common malignancy in Polish women. Management of breast cancer includes surgical treatment as well as adjuvant chemotherapy, radiotherapy, hormonal therapy, and combination regimens. One of the adverse consequences of oncological management of breast cancer may involve changes in frontal plane body posture. The objective of the study was to assess the frontal plane body posture changes in women treated for breast cancer. A prospective study including 101 of female breast cancer patients subjected to surgical treatment in the period from October 2011 to October 2012 (mastectomy was performed in 51 cases while breast conserving therapy was administered in the remaining 50 cases). The body posture in the frontal plane was assessed using the computer-assisted postural assessment system with Moiré fringe analysis. No statistically significant differences were observed in pre-operational postural parameters of interest. Exam II revealed highly significant differences in SLA values; results suggesting more pronounced dysfunction were observed in the MAS group. Exam III revealed highly significant differences in PIA, SH, SD and SLA values; results suggesting more pronounced dysfunction were observed in the MAS group. Undesirable postural changes occur both in women who were treated with radical mastectomy and in those who underwent breast-conserving surgery; breast-conserving surgery is associated with decreased severity in postural abnormalities.

Deep venous thrombosis in patients with chronic spinal cord injury.

CONTEXT/OBJECTIVE: Deep venous thrombosis (DVT) is a well-known complication of an acute spinal cord injury (SCI). However, the prevalence of DVT in patients with chronic SCI has only been reported in a limited number of studies. The aim of our study was to examine the prevalence of DVT in patients with SCI beyond three months after injury. DESIGN: Cross-sectional study. SETTING: Rehabilitation Department at the Bydgoszcz University Hospital in Poland. PARTICIPANTS: Sixty-three patients with SCI that were more than 3 months post injury. The patients, ranging in age from 13 to 65 years, consisted of 15 women and 48 men; the mean age of the patients was 32.1 years. The time from injury varied from 4 to 124 months. OUTCOME MEASURES: Clinical assessment, D-dimer and venous duplex scan. RESULTS: The venous duplex scan revealed DVT in 5 of the 63 patients. The post-injury time in four of the patients varied between 4 and 5 months; one patient was 42 months post-injury. CONCLUSION: DVT occurred in patients with chronic SCI, mainly by the 6th post injury month.

The influence of a ten-week Nordic walking training-rehabilitation program on the level of lipids in blood in overweight and obese postmenopausal women.

[Purpose] The aim of this study was to evaluate the effect of a ten-week Nordic Walking (NW) rehabilitation program on chosen anthropometric parameters and the level of basic lipids in overweight and obese postmenopausal women's blood. [Subjects and Methods] The subjects were 32 women aged 50-68 (average: 59.7 ± 5.9 years). The study was carried out following a non-randomized model and entailed NW rehabilitation 5 times a week, which lasted for 10 weeks, as well as a low-calorie 1,500 kcal diet. The therapeutic results of the study were measured through changes in anthropometric and biochemical parameters. The results were subjected to a statistical analysis. [Results] After 10 weeks of NW rehabilitation it was observed that participants lost weight and their body mass index dropped. Additionally, whereas levels of total cholesterol, LDL and triglycerides dropped, and the level of HDL increased. [Conclusion] Rehabilitation carried out according to the NW model resulted in statistically significant changes in basic lipids in blood which, considerably increased the percentage of persons who achieved the recommended level of blood lipids. Obese persons were characterised by a smaller rehabilitation weight loss. More intense workouts and cooperation with a dietician are required.

Effects of Nordic Walking and Pilates exercise programs on blood glucose and lipid profile in overweight and obese postmenopausal women in an experimental, nonrandomized, open-label, prospective controlled trial.

OBJECTIVE: Cardiometabolic effects of physical exercise depend on its intensity, duration, and type. The aim of this study was to compare the effects of two exercise models, Nordic Walking (NW) and Pilates, on postmenopausal women. METHODS: The study comprised 196 overweight or obese women: 20 were advised to maintain their previous level of physical activity (control group) whereas the others started either an NW exercise program (n = 88) or a Pilates exercise program (n = 88). Blood was collected twice for testing: before the program commenced and after it had ended. RESULTS: Of the 196 women who enrolled in the study, 147 (75%) completed the study; among those women, 69 (47%) completed a 10-week NW exercise program, 58 (39%) completed a 10-week Pilates exercise program, and 20 (14%) were in the control group. After 10 weeks, women in the NW group showed a significant reduction in body weight (6.4%), body mass index (6.4%), blood glucose (3.8%), total cholesterol (10.4%), non-high-density lipoprotein (HDL) cholesterol (16.7%), low-density lipoprotein cholesterol (12.8%), and triglycerides (10.6%), as well as an increase in HDL cholesterol (9.6%). Significantly smaller-although still favorable-changes, except for glucose and HDL cholesterol levels, were observed in the Pilates group (decreases of 1.7%, 1.7%, 1.6%, 5.3%, 8.3%, 7.5%, and 6% and an increase of 3.1%, respectively). Nevertheless, at the end of the study, the percentage of women with target concentrations of the lipid fractions had significantly increased in both exercise groups. No significant changes in the studied parameters were found in the control group. On multiple regression analysis, type of exercise program was an independent predictor of amplitude changes in most of the studied parameters. CONCLUSIONS: Exercise training in accordance with the NW model causes statistically and clinically more significant changes in glucose and basic blood lipid levels than do Pilates and dietary intervention alone.

The Probable Explanation for the Low Friction of Natural Joints.

The surface of an articular cartilage, coated with phospholipid (PL) bilayers, plays an important role in its lubrication and movement. Intact (normal) and depleted surfaces of the joint were modelled and the pH influence on the surface interfacial energy, wettability and friction were investigated. In the experiments, the deterioration of the PL bilayer was controlled by its wettability and the applied friction. The surrounding fluid of an undamaged articular cartilage, the synovial fluid, has a pH value of approximately 7.4. Buffer solutions were formulated to represent the synovial fluid with various pH values. It was found that the surface interfacial energy was stabilised at its lowest values when the pH varied between 6.5 and 9.5. These results suggested that as the PL bilayers deteriorated, the hydration repulsion mechanism became less effective as friction increased. The decreased number of bilayers changed the wettability and lowered PL lubricant properties.