32 Vol. 15 No. 1 February 2003 BIOMECHANICAL ANALYSIS OF KNEE OSTEOARTHRITIS PATIENTS AFTER THE TREATMENT OF GLUCOSAMINE PEI-HSI CHOU 1, SHEN-KAI CHEN 1, YOU-LI CHOU 2 SIU-WAI LEE 2, FONG-CHING Su, TING-SHENG LIN department of Orthopedic Surgery, Kaohsiung Medical University, Kaohsiung 2 lnstitute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan ABSTRACT Osteoarthritis (OA) encompassed a large and heterogeneous number of disorders affecting joints and bones, hones, which culminate in a joint failure. In general, OA can be he defined as a degenerative disease characterized by biomechanical and architectural deteriorations of the articular cartilage. After the age of 60 years, more than 80% of the people have radiological signs ofoa in the knee, and 20% of the people suffer from pain and movement limitations. Currently used pharmacologic treatments, including acetaminophen and nonsteroidal anti-inflammatory drugs, do not slow or reverse the degenerative process in osteoarthritis. Glucosamine, a chondro-protective substance, has recently received a great deal of attention from the public as a potential treatment of osteoarthritis, prompting healthcare professionals to investigate its clinical usefulness and potential for adverse effects. Improvement in the symptoms of osteoarthritis associated with the use of glucosamine has been observed in clinical trials. The purpose of this study was to better define the efficacy of these chondroprotective agents in treating OA. The short term and long term results were evaluated with pain score, and the most importantly, we proposed to objectively evaluate the muscle strength, and the joint motion with gait and sit-to-stand analysis. These data will warrant a better understanding of the efficacy of these chondro-protective agents in treating osteoarthritic patients. Biomed Eng Appl Basis Comm, 2003 (February); 15: 32-37. Keywords: gait, glucosamine, muscle strength, osteoarthritis, sit-to-stand chair and climbing stairs. The main pathology of OA 1 nvtronilptiolv would appear to be the progressive and/or active dete- 1. Ill 1RUUUL 1 IKJiy rioration of the articular cartilage of the joint. Drugs for the treatment of OA have been classified as symp- Osteoarthritis(OA) is one of the most prevalent tom-modifying drugs and also as structure-modifying diseases in the elderly. OA of the knee is particularly drugs. Several short-term to medium-term clinical tridebilitating as this joint is stressed in many of the ac- als in OA have shown the significant symptomtivities of daily living such as walking, rising from a modifying effect of glucosamine sulphate and its good safety profile. The OA patients on placebo had a pro- Received: Oct. 30,2002; Acceped: Dec. 15, 2002 gressive joint-space narrowing loss after 3 years, but Correspondence: You-Li Chou, Ph.D., Professor no significant joint-space loss in the OA patients on Institute of Biomedical Engineering, National Cheng glucosamine sulphate[l]. OA patients have a poorer Kung University, No. 1 University Road, Tainan 701, flexibility in both the affected and unaffected legs and Taiwan demonstrate significantly less knee angular velocity E-mail: ylchou@mail.ncku.edu.tw and knee range of motion during gait[2]. Long- 32
BIOMEDICAL ENGINEERING- APPLICATIONS, BASIS & COMMUNICATIONS duration walking in the elderly obese will lead to quadriceps fatigue. Changes in the gait pattern due to fatigue will lead to altered knee kinematics at heel-strike and consequently decreased shock absorption, which could cause articular cartilage degeneration[3].in patients with knee OA, the tibia femoral knee angle and adduction moment may not persist because subjects may adapt their gait to decrease pain and loads[4]. Furthermore it has been shown that the external knee adduction moment in an OA population is greater than that observed in normal, higher magnitudes of the external adduction moment may lead the development and progression of medial compartment OA[5]. Subjects with OA and a higher body mass index have a lower knee extensor moment, the female subjects had significantly greater knee flexion and a greater knee extensor moment[6]. In sit-to-stand analysis, The elders tended to flex the trunk more and at a higher velocity, thus gaining a higher momentum. Elders rotated the body forward and started elevation, young individuals rotated and raised in a synergetic manner[7]. Quadriceps strength, knee pain, and age are more important determinants of functional impairment in elderly subjects, maximum peak torque loss of knee flexors and extensors was found in both patient groups with respect to controls by isokinetic test[8]. Patients with knee OA have reduced functional capacity and muscle function, muscle strength, endurance and contraction speed were significantly decreased with the respect control group[9].biomechanical measures have often been used to quantify kinematic and kinetic patterns of lower limb and joint movement for functional activities such as gait, sit-to-stand. The propose of this study was to examine the differences in gait characteristics, sit-to-stand mechanics and the isokinetic knee strength with symptomatic OA of the knee after six month treatment with glucosamine. 2. METHOD 2.1 Subjects There were 10 volunteer subjects diagnosed with knee OA(Grade II and 11 1), 8 females and 2 males, included in this investigation. Mean (SD) age, height and weight data were 60.7 years (3.9 years), 157 cm (6.5 cm) and 70.4 kg (11.3 kg). 2.2 Gait Analysis The study was based on the model of the individual joint as a perfect ball and socket joint. The gait laboratory in which this study was carried out was equipped with a motion analysis system which included six charge coupled device cameras, two video processors, a SUN workstation, and fifteen retroreflective markers (Helen Hayes Simplified Marker Set). The trajectory data of the markers were recorded at a 60 Hz sampling rate. A low-pass Butterworth filter smoothed raw data from the three-dimensional video with a cut-off frequency of 6 Hz. The kinematic and kinetic data were calculated by software OrthoTrak IV. Five trials were recorded for each subject, and walking with their most comfortable speed. 2.3 Sit-to-Stand Analysis All subjects performed five trials of a STS task from a adjustable chair. One foot was placed on force plate, which the ground reaction forces were recorded at 60 Hz. Movement of lower extremity was recorded at 60 Hz using a video camera. A total of 5 retroreflective spherical markers were applied on anatomical landmarks. The markers were attached on the skin surface, one each at the space between the second and third metatarsal bones, lateral malleolus, fibula head, greater trochanter and the acromion process. Each subject was tested with barefoot and the height of the chair was adjusted as high as knee-heel height. The subject performed the STS movement at a self-selected comfortable speed with the arms folded in front of the body. 2.4 Isokinetic Strength Test After completion of the anthropometric measures, an isokinetic strength test was administered for knee flexion and extension using Kin-Corn dynamometer. Before testing, a warm-up was provided to habit the testing equipment. Subjects wore a double shoulder seat belt to stabilize the upper body. The distal ends of the thigh and shank were strapped to the seat and the dynamometer arm. Resting interval of 60s between each trial. The lever arm of the dynamometer aligned with the knee joint center. The biomechanical measurement included the knee flexor (hamstring) and the extensor (quadriceps) muscle strength of concentric contraction at 30 deg/s and 60 deg/sec. 2.5 Statistical Analysis One way ANOVA of the repeated measured and Post Hoc test were used to investigate whether there were any differences in gait sit-to-stand and muscle strength parameters among the four groups. Differences were considered significant when the P value was less than 0.05. 3. RESULTS 33 3.1 Gait Analysis There were significant differences among the four groups in velocity, cadence, step length and stride length (Table 1). In velocity, the Post-6 group walked with the fastest speed (112.3 cm/sec), following by the group Post-3 (97.0 cm/sec) and Post-1 (90.2 cm/sec). The Post-6 also walked with the maximal ca- -33-
34 Vol. 15 No. 1 February 2003 4 Post-1 Post-3 Post-6 Fig. 1 Maximum joint angle of ankle in the horizontal 70 so 45. j/ Pro Post-1 Post-3 T Post-6 Fig. 2 Maximum joint angle of knee in the Sagittal dence(107.9 steps/min) and had the maximum stride length (134.6 cm)and step length(69.4cm).the ankle's angle at heel strike in the horizontal plane of group Pre (10.81 ' ) were significantly greater than that of the other group(figure 1). The knee's angle at swing phase in the" sagital plane(figure 2) of group Pre (48.21 ` ) was significantly less than that of group post- 1( 52.32 ` ),Post-3(58.13 ) and Post-6(67.1 ` ). All OA subjects have knee varus, but before and after treatment of glucosamine, there was no significant differences among the four groups(figure 3). In the kinetic analysis, the knee's extension moment at a stance phase of group Post-6 (0.87 N*m/kg) was significantly greater than that of group Pre and group Post-I (Figure 4). 3.2 STS Analysis Add 30 20 26-24- 22-20- Is - Is - 14-12 t0 8 6 4 2 0 Abd -4J Pre Post-1 Post-3 ----- Post-6 0 20 40 60 50 100 120 140 % of Gait Cycle Fig. 3 Maximum joint angle of knee in the frontal 0.9. 0.0 0.7 c E 0.6 0 rc 0.5 4t 0.4 0.3 0.2 0.1 Pro Post-1 Post-3 Post-6 Fig. 4. Maximum joint moment of knee in the sagittal The hip joint reached the maximal flexion angle at the end of the forward leaning phase. The maximal flexion angle of the hip was the largest for the Pre group while rising from the adjustable chair. Significant differences were found between four groups (p<0.05). The maximal flexion angle of the knee also occurred at the end of the forward leaning phase. There were no significant differences among the four groups. The maximal dorsiflexion angle of the ankle was not significantly different among the four groups (Table 2). Maximal flexion moments of the hip, knee and maximal dorsiflexion moment of the ankle occurred at the beginning of the extension phase (Table 3). Group Post-6 had lower maximal flexion moments of the hip than other groups. The differences of maximal hip flexion moment were significant among the -34-
BIOMEDICAL ENGINEERING- APPLICATIONS, BASIS & COMMUNICATIONS 35 30 deg/sec ipre! Post-1! Post-3 I Post-6 380 360 340 320 300 280 260 240 220 200 180 160-140- 120-100- 80-60 40-20 30 deg/sec m.m mm Pre 77///, Post-1 KSS Post-3 Post-6 60 deg/sec flexor(con) 30 deg/sec 320 300 280 260-240 220 200 180 160 140 120-100 80 60 40 20 60 deg/sec I 1 FFfffRlPre 77///, Post-1 8SS5 Post-3 WS Post-6 rttt^pre Y7//L Post-1 S\SS5 Post-3 i Post-6 I i Fig. 5 Ioskinetic concentric strength data for the knee extensor and flexor four groups. The maximal knee moment occurred in Post-6 group. The maximal knee moments between Post-6 group and Pre group are significantly different (p<0.05). Fig. 6 Total work data for the knee extensor and flexor 3.3 Muscle Strength The results of the maximal isokinetic concentric strength for knee extensor (quadriceps) and flexor -35-
36 Vol. 15 No. 1 February 2003 Table 1. Spatial Temporal Parameters N=10 Pre Post-1 Post-3 Post-6 Velocity (cm/sec)* 81.7 ± 8.9 90.2± 12.9 97.0 ±15.0 112.3±12.2 Cadence (steps/mm n) 88.5 ±9.3 92. 9±10.1 98.2 ±13.6 107.9±11.6 Step length (cm)* 55.0±6.54 58.8± 3.87 62.2 ±1.81 69.4±5.7 Stride length (cm)* 110.8±5.9 114.6 ±4.3 122.7 ±5.3 134.6±5.4 Step width (cm) 14.5 ±1.8 13.6 ±1.9 12.7 ±2.6 12.9±2.1 Table 2. Maximum joint angle of STS cycle N=10 Pre Post-1 Post-3 Post-6 Max angle of hip* 104.6±5.8 98.4±3.7 88.6±4.6 84.3±4.9 Max angle of knee 78.9±6.0 81.9 ±4.9 79.1±8.3 78.2±6.4 Max angle of ankle 14.6±3.48 15.1±3.3 14.4 ±3.06 14.2±3.28 Table 3 Maximum joint moment of STS cycle N=10 Pre Post-I Post-3 Post-6 Max moment of hip* 0.048±0.014 0.041±0.011 0.040-±0.007 0.037±0.027 Max moment of knee* 0.029±0.016 0.030±0.007 0.036±0.005 0.045±0.021 Max moment of ankle 0.024 ± 0.005 0.020 ± 0.007 0.014 ± 0.008 0.017±0.003 (hamstring) were shown in Figure 5 and the total work were shown in Figure 6. The OA subjects' knee extensor and flexor muscle strength was significantly increased after the treatment of glucosamine and the total work in post-group was increased or significantly greater than that in pre-group. 4. CONCLUSION With the context of this study, the following conclusions are in order: (1) After six months treatment of glucosamine, the articular pain disappearanced or reduced. (2) Glucosamine can improve the joint function and the muscle strength at the knee with osteoarthritis. (3) Medium-term clinical trials of six months in osteoarthritis patients have shown the significant symptom modifying effect of glucosamine and its good safety profile. REFERENCE 1. Messier SP, Loeser RF, Hoover JL, Semble EL, Wise CM.: Osteoarthritis of the knee : effects on gait, strength, and flexibility. Arch Phys Med Rehabil 1992; 73:29-36 2. Reginster JY, Deroisy R, Rovati LC, Lee RL, Lejeune E, Bruyere 0, Glacovelli G, Henrotin Y, Dacre JE, Gossett C : Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomized, placebo-controlled clinical trial. The Lancet. 2001;357:27. 3. Syed IY. Davis BL.: Obesity and osteoarthritis of the knee : hypothesis concerning the relationship between ground reaction forces and quadriceps fatigue in long-duration walking. Medical hypothesis 2000;54:1825. 4. Hurwitz DE, Summer DR, Andriacchi TP, Sugar -36-
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