Hip Joint Space Research Articles

Long-term outcome of undisplaced fatigue fractures of the femoral neck in young male adults

The incidence and long-term outcome of undisplaced fatigue fractures of the femoral neck treated conservatively were examined in Finnish military conscripts between 1970 and 1990. From 106 cases identified, 66 patients with 70 fractures were followed for a mean of 18.3 years (11 to 32). The original medical records and radiographs were studied and physical and radiological follow-up data analysed for evidence of risk factors for this injury. The development of avascular necrosis and osteoarthritis was determined from the follow-up radiographs and MR scans. The impact of new military instructions on the management of hip-related pain was assessed following their introduction in 1986. The preventive regimen (1986) improved awareness and increased the detected incidence from 13.2 per 100,000 service-years (1970 to 1986) to 53.2 per 100,000 (1987 to 1990). No patient developed displacement of the fracture or avascular necrosis of the femoral head, or suffered from adverse complications. No differences were found in MRI-measured hip joint spaces at final follow-up. The mean Harris Hip Score was 97 (70 to 100) and the Visual Analogue Scale 5.85 mm (0 to 44). Non-operative treatment, including avoidance of or reduced weight-bearing, gave favourable short- and long-term outcomes. Undisplaced fatigue fractures of the femoral neck neither predispose to avascular necrosis nor the subsequent development of osteoarthritis of the hip.

A computer-based image analysis method for assessing the severity of hip joint osteoarthritis

A computer-based image analysis method was developed for assessing the severity of hip osteoarthritis (OA). Eighteen pelvic radiographs of patients with verified unilateral hip OA, were digitized and enhanced employing custom developed software. Two ROIs corresponding to osteoarthritic and contralateral-physiological radiographic Hip Joint Spaces (HJSs) were determined on each radiograph. Textural features were extracted from the HJS-ROIs utilizing the run-length matrices and Laws textural measures. A k-Nearest Neighbour based hierarchical tree structure was designed for classifying hips into three OA severity categories labeled as “Normal”, “Mild/Moderate”, and “Severe”. Employing the run-length features, the overall classification accuracy of the hierarchical tree structure was 86.1%. The utilization of Laws’ textural measures improved the system classification performance, providing an overall classification accuracy of 94.4%. The proposed method maybe of value to physicians in assessing the severity of hip OA.

Clinical results of femoral head replacements for femoral intertrochanteric fractures in the elderly

目的 将高龄股骨转子间骨折的人工股骨头置换术与高龄股骨颈骨折行人工股骨头置换术的临床结果相比较,探讨人工股骨头置换术治疗高龄股骨转子间骨折的经验、适应证以及早中期随访结果.方法 对1996年8月～2002年4月间行人工股骨头置换术治疗的80岁以上新鲜的40例股骨转子间骨折和45例股骨颈骨折高龄患者进行回顾性分析,将随访结果进行比较和评估,并进行统计学分析.结果 两组随访时间均为3～7年,转子间骨折组平均4.6年,股骨颈骨折组平均5.5年.两组在住院时间、术中出血量、术后引流量、术后扶拐下地时间和术后早期并发症等方面比较,差异无显著性意义(P＞0.05).转子间骨折组比股骨颈骨折组手术时间长,术后出现双下肢不等长的可能性高,差异有显著性意义(P＜0.05).末次随访的Harris髋关节评分,两组比较差异无显著性意义(P＞0.05).术后并发症情况:在深静脉血栓、髋关节间隙变化、疼痛、假体柄松动下沉等方面,两组比较差异无显著性意义(P＞0.05).两组假体翻修率差异无显著性意义(P＞0.05),均未见因髋臼磨损而发生髋臼内陷甚至中心性脱位.结论 使用标准骨水泥型股骨假体,股骨转子间骨折行人工股骨头置换术取得了与股骨颈骨折行人工股骨头置换术相同的临床效果。

Osteoarthritis severity of the hip by computer-aided grading of radiographic images

A computer-aided classification system was developed for the assessment of the severity of hip osteoarthritis (OA). Sixty-four radiographic images of normal and osteoarthritic hips were digitized and enhanced. Employing the Kellgren and Lawrence scale, the hips were grouped by three experienced orthopaedists into three OA-severity categories: Normal, Mild/Moderate and Severe. Utilizing custom-developed software, 64 ROIs corresponding to the radiographic Hip Joint Spaces were manually segmented and novel textural features were generated. These features were used in the design of a two-level classification scheme for characterizing hips as normal or osteoarthritic (1st level) and as of Mild/Moderate or Severe OA (2nd level). At each classification level, an ensemble of three classifiers was implemented. The proposed classification scheme discriminated correctly all normal hips from osteoarthritic hips (100% accuracy), while the discrimination accuracy between Mild/Moderate and Severe osteoarthritic hips was 95.7%. The proposed system could be used as a diagnosis decision-supporting tool.

The relationship between acetabular retroversion and osteoarthritis of the hip

Excessive acetabular cover secondary to a retroverted acetabulum causes pincer impingement, which may cause early osteoarthritis of the hip. Our aim was to determine if there was a relationship between acetabular version and osteoarthritis of the hip. Using image processing and analysis software we studied 117 CT images of the hip in patients aged less than 65 years who had undergone a CT virtual colonoscopy. The mean CT joint space of the 18 hips with acetabular retroversion was narrower compared with the 99 hips with normal acetabular alignment (p < 0.0001). A correlation of r = 0.46 (p < 0.01) was found between right hip acetabular version and the mean right hip joint space and of r = 0.31 (p = 0.02) between left hip acetabular version and the mean left hip joint space. Acetabular retroversion is associated with radiological evidence of osteoarthritis of the hip. An understanding of the mechanical basis of osteoarthritis of the hip allows early treatment of the underlying structural abnormality and prevents progression of the degenerative condition.

Assessing hip osteoarthritis severity utilizing a probabilistic neural network based classification scheme

A computer-based classification system is proposed for the characterization of hips from pelvic radiographs as normal or osteoarthritic and for the discrimination among various grades of osteoarthritis (OA) severity. Pelvic radiographs of 18 patients with verified unilateral hip OA were evaluated by three experienced physicians, who assessed OA severity employing the Kellgren and Lawrence scale as: normal, mild/moderate and severe. Five run-length, 75 Laws’ and 5 novel textural features were extracted from the digitized radiographic images of each patient's osteoarthritic and contralateral normal hip joint spaces (HJSs). Each one of the three sets of textural features (run-lengths, Laws’ and novel features) was separately utilized for assigning hips into the three OA severity categories, by means of a probabilistic neural network (PNN) classifier based hierarchical tree structure. The highest classification accuracy (100%) for characterizing hips as normal, of mild/moderate or of severe OA was obtained for the novel textural features set. Additionally, the novel textural features were used to design a mathematical regression model for providing a quantitative estimation of OA severity. Measured OA severity values, as expressed by HJS-narrowing, correlated highly ( r = 0.85, p < 0.001) with the predicted values by the mathematical regression model. The proposed system may be valuable in OA-patient management.

Correlates of knee pain in older adults: Tasmanian older adult cohort study

To describe the association between chondral defects, bone marrow lesions, knee and hip radiographic osteoarthritis (OA), and knee pain. Knee pain was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index. T1- and T2-weighted fat saturation magnetic resonance imaging was performed on the right knee to assess chondral defects and subchondral bone marrow lesions. Radiography was performed on the right knee and hip and scored for radiographic OA. Body mass index (BMI) and knee extension strength were measured. A total of 500 randomly selected men and women participated. The prevalence of knee pain was 48%. In multivariable analysis, prevalent knee pain was significantly associated with medial tibial chondral defects (odds ratio [OR] 2.32, 95% confidence interval [95% CI] 1.02-5.28 for grade 3 versus grade 2 or less; OR 4.93, 95% CI 1.07-22.7 for grade 4 versus grade 2 or less), bone marrow lesions (OR 1.44, 95% CI 1.04-2.00 per compartment), and hip joint space narrowing (OR 1.36, 95% CI 1.07-1.73 per unit), as well as greater BMI and lower knee extension strength. It was not significantly associated with radiographic knee OA. These variables were also associated with more severe knee pain. In addition, there was a dose response association between knee pain and number of sites having grade 3 or 4 chondral defects (OR 1.39, 95% CI 1.12-1.73 per site), with all subjects having knee pain if all compartments of the knee had these defects. Knee pain in older adults is independently associated with both full and non-full-thickness medial tibial chondral defects, bone marrow lesions, greater BMI, and lower knee extension strength, but is not associated with radiographic knee OA. The association between radiographic hip OA and knee pain indicates that referred pain from the hip needs to be considered in unexplained knee pain.

Quantitative assessment of hip osteoarthritis based on image texture analysis

A non-invasive method was developed to investigate the potential capacity of digital image texture analysis in evaluating the severity of hip osteoarthritis (OA) and in monitoring its progression. 19 textural features evaluating patterns of pixel intensity fluctuations were extracted from 64 images of radiographic hip joint spaces (HJS), corresponding to 32 patients with verified unilateral or bilateral OA. Images were enhanced employing custom developed software for the delineation of the articular margins on digitized pelvic radiographs. The severity of OA for each patient was assessed by expert orthopaedists employing the Kellgren and Lawrence (KL) scale. Additionally, an index expressing HJS-narrowing was computed considering patients from the unilateral OA-group. A textural feature that quantified pixel distribution non-uniformity (grey level non-uniformity, GLNU) demonstrated the strongest correlation with the HJS-narrowing index among all extracted features and utilized in further analysis. Classification rules employing GLNU feature were introduced to characterize a hip as normal or osteoarthritic and to assign it to one of three severity categories, formed in accordance with the KL scale. Application of the proposed rules resulted in relatively high classification accuracies in characterizing a hip as normal or osteoarthritic (90.6%) and in assigning it to the correct KL scale category (88.9%). Furthermore, the strong correlation between the HJS-narrowing index and the pathological GLNU (r = -0.9, p<0.001) was utilized to provide percentages quantifying hip OA-severity. Texture analysis may contribute in the quantitative assessment of OA-severity, in the monitoring of OA-progression and in the evaluation of a chondroprotective therapy.

Falls risk is associated with pain and dysfunction but not radiographic osteoarthritis in older adults: Tasmanian Older Adult Cohort study

To describe the association between knee and hip radiographic osteoarthritis (ROA), a measure of knee pain, stiffness and functional ability and objectively measured physiological falls risk predictors. Cross-sectional, population-based study of 850 randomly selected men and women aged 50-80 years (mean 62.5, SD 7.4). Falls risk (Z score) was determined objectively with the short form Physiological Profile Assessment (PPA). Two observers assessed knee and hip ROA using the Altman atlas. Pain, stiffness and functional ability were assessed using the Western Ontario McMasters Osteoarthritis index (WOMAC). Overall, the study population was at a mild risk of falling. In multivariable analysis, the WOMAC function and pain score were significantly associated with reaction time, balance, proprioception, knee extension strength, and edge contrast sensitivity. Stiffness was associated with knee extension strength and edge contrast sensitivity. Males had a dose response association between the global WOMAC score and falls risk (r=0.17, P<0.001). Those who reported a global WOMAC score of 50 and above had a higher risk of falling compared to those with a score below 50 (Z score: 0.53 vs 0.14, P<0.001). Hip joint space narrowing (JSN) was significantly associated with knee extension strength (r=-0.10, P=0.003), however, no other significant associations were observed between ROA and falls risk predictors. Self-reported functional ability and pain, and to a lesser extent, stiffness (but not knee and hip ROA), have a modest but independent association with physiological predictors of falls risk.

Cancellous bone changes in hip osteoarthritis: a short-term longitudinal study using fractal signature analysis

To quantify changes to the trabecular structure in the femoral heads of patients with hip osteoarthritis (OA). Patients with OA (n=14; F=7), mean (standard deviation age) 50.6 (10.1) years, had macroradiographs at approximately x4 magnification at baseline and 18 months later using a standardized protocol. Following digitization, computerized measurement was obtained of minimum hip joint space width and fractal signature analysis (FSA) measured longitudinal changes separately in the principal compressive (vertical) and horizontal trabeculae at the region of interest within the centre of the head. The patient group had mean annual rate of joint space narrowing of 0.14+/-0.36 mm/yr. FSA detected no significant changes in horizontal trabeculae, whereas the larger principal compressive (vertical) trabeculae (0.96 mm to 1.02 mm) increased significantly in thickness and the fine to medium trabeculae (0.18 mm to 0.54 mm) decreased significantly in number. The increased thickness of the larger trabeculae within the compressive structural element of the femoral head is a response to the increase in stress associated with an overall loss of trabeculae in this region, suggesting the presence of an osteoporosis within the femoral head in OA patients.

P243 The hip joint space width is in relation with the acetabular roof shape: The shorter the roof, the thicker the joint space

P243 The hip joint space width is in relation with the acetabular roof shape: The shorter the roof, the thicker the joint space

Factors influencing hip joint space in asymptomatic subjects: A survey of 4151 subjects of the Copenhagen City Heart Study: The Osteoarthritis Substudy

Objective The aims of the study were to investigate the distribution of hip joint space width (JSW) in asymptomatic subjects without radiologic evidence of degeneration, and investigate the influence of age, sex, physical parameters, occupational activity, and smoking on JSW. Materials and methods The distribution of minimum JSW was determined in hip joints in standardized, weight-bearing pelvic radiographs of the Copenhagen City Heart Study: The Osteoarthritis Substudy cohort of 4151 subjects. Asymptomatic subjects without radiologic osteoarthritis were included (1018M/1554F). Occupational exposure to repeated daily lifting, smoking, and physical parameters were registered for each individual. Results Overall, female minimum JSW was significantly smaller compared with male JSW ( P<0.0001). Female minimum JSW decreased significantly with age ( P<0.0001), while male minimum JSW remained relatively unaltered throughout life ( P right=0.19; P left=0.18). Minimum JSW correlated positively with height, weight, and BMI, as did femoral head radius. Multiple logistic regression analysis revealed significant influence of sex and age on minimum JSW in females only. Positive or adverse effects of cigarette smoking on hip JSW were not documented. Type and duration of occupational exposure to repeated daily lifting did not affect hip JSW significantly. Conclusion Minimum JSW decreased progressively with age in women, while it was unaltered in men. A history of smoking or different occupational exposure to repeated daily lifting did not influence minimum hip JSW significantly. Differences in body mass index, height or weight did not significantly influence minimum hip joint JSW.

The relationship of hip joint space to self reported hip pain: A survey of 4.151 subjects of the Copenhagen City Heart Study: the Osteoarthritis Substudy

Objectives (1) To evaluate the effect of pelvic orientation on measurements of hip joint space widths (JSW) in cadaver pelvic radiographs, thereby validating the pelvic radiographs of the Copenhagen City Heart Study: The Osteoarthritis Substudy (CCHS III) cohort of 4.152 subjects, and (2) to investigate the relationship between minimal JSW and self reported hip pain of the cohort. Methods (1) Cadaver pelves and proximal femora of one male and one female donor were mounted in holding devices permitting independent rotation (total arc of 42°), and inclination/reclination (total arc of 24°). At each 3° increment an anteroposterior radiograph was recorded. Measurements of JSW were performed. (2) Self reported recurrent pain in or around the hip joint during 12 months prior to baseline examinations, and minimum JSW in pelvic radiographs of the cohort were registered. Relationships between minimum JSW and self reported pain were investigated. Results (1) Measurements of hip JSW in cadaver radiographs were not influenced significantly by rotation. Measurements of JSW were inconclusively influenced by varying inclination/reclination. (2) Minimum JSW ≤ 2.0 mm was significantly associated to self reported pain in or around the hip joint in both sexes. Conclusion Measurements of minimum hip JSW did not seem to be significantly influenced by varying spatial orientation of the pelvis during X-ray recordings. An inclusion criteria of minimum JSW ≤ 2.0 mm designating definite degenerative pathology in hips will be used by the current authors in future studies.

Gait analysis in an osteoarthritis patient with restoration of the hip joint space following contralateral total hip arthroplasty: a case report

We present the case of a patient who, after undergoing unilateral total hip arthroplasty (THA), achieved pain reduction in the contralateral hip accompanied by restoration of the radiographic joint space. We conducted gait analysis to clarify the dynamic factors affecting the natural course of osteoarthritis (OA). Our findings revealed that the patient walked with exaggerated adduction of the hip following the contralateral THA, causing substantial regeneration of joint loading.

HIP PAIN IN A MIDDLE AGED MALE

HISTORY A 50 year old white male presented to the office with a 3 month history of progressive right hip pain. He first noticed the pain when he was playing volleyball in a pool. The pain was located in the right lateral hip with radiation to the lateral thigh, anterior hip, and groin. These symptoms initially improved slightly, but worsened slightly with white water rafting and substantially after playing basketball. He denied any falls or direct trauma to the hip. He denied low back pain, paresthesias, weakness, and loss of bowel or bladder function. The pain was increased with cough and sneeze. He had no fevers, chills, night sweats, or weight loss. He had mild night pain associated with movement, but the pain did not awake him. No other joint problems. He had previously been diagnosed with referred pain secondary to lumbar radiculopathy. He had no relief with PT and Prednisone. An MRI of the lumbar spine was normal. He had no personal or family history of gout, lupus, or symptoms suggestive of inflammatory arthropathies. PHYSICAL EXAMINATION He ambulated with a marked limp. Flexion was to within four inches of the floor with restricted extension. Neurological exam, including straight leg raise, motor, sensation, and reflexes, was normal. Hip exam revealed marked pain with log rolling. Quadrant test was significantly positive. His ROM showed reduced flexion, internal and external rotation associated with marked pain. DIFFERENTIAL DIAGNOSIS Hip osteoarthritis Avascular necrosis Septic arthritis of the hip Trochanteric bursitis Occult hip fracture Malignancy TESTS AND RESULTS X-ray of the hip showed no acute bony abnormality or joint space narrowing. MRI showed a uniformly abnormal appearance of the bone marrow in the right femoral head, femoral neck, and inter-trochanteric region. This was a homogenous abnormality with diminished signal on T1 weighted images and increased signal on T2 images. There were no focal areas of marrow abnormality. Trace effusion. No fracture. Hip joint spaces were relatively well maintained. The left femoral head was normal in appearance. Adjacent soft tissues were normal. FINAL/WORKING DIAGNOSIS Idiopathic Transient Osteoporosis of the Hip TREATMENT AND OUTCOME Treatment is supportive with pain control and avoidance of provoking factors. The patient's symptoms are improving with indomethacin. Expect spontaneous resolution over a period of months.

Significance of Laboratory and Radiologic Findings for Differentiating Between Septic Arthritis and Transient Synovitis of the Hip

Although significant differences exist in the methods of treatment and prognoses of septic coxitis and transient synovitis in children complaining of acute hip pain, similar symptoms are present in these two diseases at the early stages, and differential diagnosis is difficult. To differentiate between these two diseases, the authors evaluated the clinical, serologic, and radiologic findings and tried to determine factors that could be used as diagnostic criteria. The authors performed a retrospective study by evaluating medical records, plain hip radiographs, and clinical findings in 97 patients with transient synovitis and 27 patients with septic arthritis. Univariate analysis showed significant differences in body temperature, serum WBC count, and ESR and CRP levels of the two patient groups. Plain radiographs showed a displacement or blurring of periarticular fat pads in all patients with acute septic arthritis, and multivariate regression analysis showed that body temperature >37 degrees C, ESR >20 mm/h, CRP >1 mg/dL, WBC >11,000/mL, and an increased hip joint space of >2 mm were independent multivariate predictors of acute septic arthritis. The authors conclude that the independent multivariate predictors are effective indices for the differential diagnosis of acute septic coxitis and transient synovitis.

Age and sex differences in hip joint space among asymptomatic subjects without structural change: implications for epidemiologic studies.

The prevalence of hip osteoarthritis (OA) increases significantly with age. Although it is not clear whether joint space loss at the hip is a feature of normal aging or a reflection of the OA process, epidemiologic criteria for OA are based on narrowing alone. The aim of this study was to determine whether changes in joint space width occur with age, and whether there are sex differences, in asymptomatic subjects without hip OA. We identified a total of 1,806 subjects who had undergone intravenous urography between 1994 and 1996 and sent a questionnaire to the 1,527 of these subjects who were alive in 1998; 1,031 replies (68%) were received. All radiographs were read by an observer blinded to age, sex, and pain status. Individual radiographic features of OA (narrowing, osteophyte, sclerosis, and cysts) were graded, and an overall qualitative grade was allocated, according to a standard atlas. Minimum joint space width (JSW) was measured by metered caliper to within 0.1 mm. A total of 276 women (mean age 63 years) and 257 men (mean age 64 years) were identified who had never had hip pain (defined as having ever had pain on most days for at least 1 month) and who had no evidence of either joint space narrowing or osteophyte (grade 0, no structural changes). The minimum JSW in either hip was tabulated according to age. JSW measurement was reproducible (95% confidence limits of agreement) to within +/-0.5 mm. At all ages, men had larger JSW than women (3.85 mm in women, 4.19 mm in men, mean difference 0.34 mm; 95% confidence interval [95% CI] 0.24, 0.44). A significant decline in JSW with age was seen in women, with a mean difference between ages 45-54 and 75-84 years of 0.36 mm (95% CI 0.15, 0.58; P = 0.001). No significant change in JSW with age was seen in men (mean difference 0.16 mm; 95% CI -0.11, 0.43). Analysis of an additional 64 women and 61 men who were without hip pain and had overall qualitative grade 1-2 changes gave similar results. Implementing these results to alter the threshold for definition of hip OA in women from < or =2.5 mm to < or =2.2 mm reduced the prevalence of hip OA from 10.6% to 5.6%. These sex differences in joint space have significant implications in terms of the major emphasis on joint space narrowing in definitions of hip OA. Women also have a significant progressive decline in joint space with age that is not seen in men. This suggests that in women, loss of cartilage may be an age-related phenomenon that is independent of other aspects of structural change. Consideration should be given to the development of sex-specific definitions of hip "OA."

Two cases of osteochondromatosis which developed in the iliopectineal bursa of an osteoarthritic hip

Two osteoarthritis patients had osteochondromatosis in the iliopectineal bursa which communicated with the hip joint space. They received surgical resection of the cystic mass and total hip arthroplasty and had good clinical outcomes. The authors consider that these patients' osteochondromatosis was a secondary development on the synovium of the iliopectineal bursa due to chronic inflammation caused by osteoarthritis.

Measurement of the radiological hip joint space width. An evaluation of various methods of measurement

Objective To determine the most relevant method of measurement of the radiographic hip joint space width (JSW).Design Seventy hips were examined from 36 patients of the ECHODIAH study having had one to four X-rays of the pelvis during the 3-year course of the study. Minimum interbone distance (MIDc), mean width of both the whole joint space (MJSWL) and a region of interest of the joint space (MJSWroi) were measured using computerized analysis of digitized radiographs. MID was also measured using a graduated eyepiece (MIDge). Reproducibility of the measurement was assessed by the intraclass coefficient of correlation. Sensitivity to change was evaluated by the standardized response mean.Results The intraobserver intraclass coefficient of correlation of MIDc and MJSWroi was 0.98 and 0.94, respectively. The mean value°S.D. of MJSWL, MJSWroi, MIDc and MIDge was 3.3°0.9, 2.6°0.9, 2.4°0.9 and 2.6°1.2mm, respectively. MIDge was significantly larger than MIDc (mean difference: 0.21°0.62mm,P 0.001), in both normal and osteoarthritic hips. However, the difference between MIDge and MIDc varied largely when considering topography of femoral head migration. Whatever the method was, a significant (P 0.001) mean decrease of nearly 0.5mm was found in osteoarthritic hips over the 3 year follow-up. The standardized response mean for MJSWL, MJSWroi, MIDge and MIDc was 0.73, 0.75, 0.79 and 0.85, respectively. Superiority of MIDc, in term of sensitivity to change, was mainly seen in osteoarthritic hips showing a superomedial or a concentric migration of the femoral head.Conclusion Minimum interbone distance measured with a computer assisted method is suggested as the most suitable method for the evaluation of hip osteoarthritis (OA) progression.

A 5-year randomized controlled, double-blind study of glycosaminoglycan polysulphuric acid complex (Rumalon®) as a structure modifying therapy in osteoarthritis of the hip and knee

Objective To determine the structure (disease) modifying effect of a glycosaminoglycan polypeptide association complex (GP-C; Rumalon®) in patients with knee and hip osteoarthritis (OA).Methods Double-blind, randomized, placebo-controlled five-year study. Primary assessment criterion was change in radiographic joint space width between baseline and follow-up at 5 years. Secondary outcome criteria included Lequesne algofunctional index (LAI), pain on passive motion and consumption of non-steroidal antiinflammatory drugs (NSAIDs). The patients received 10 courses of injections of placebo or GP-C 2ml intramuscularly in 5 years (two courses each year). Each course included 15 injections administered twice weekly.Results There were 277 patients with knee OA and 117 patients with hip OA. Control and GP-C treated groups were comparable as to sex, age, duration of disease, body weight, X-ray stage and value of LAI at the baseline. Knee joint space at 5 years decreased 0.37±0.08 (mean±standard deviation) mm for GP-C and 0.42±0.08mm for placebo groups (P=0.68). Hip joint space at 5 years decreased 0.21±0.08mm for GP-C and 0.22±0.08mm for placebo groups (P=0.53). In a subset of patients with hip OA, Kellgren–Lawrence≥2 and JSW≥1mm, there was a trend in favor of GPC for lower joint space narrowing in 5 years (P=0.11). In addition, there were no statistical differences between the treatment groups in LAI, pain on passive motion and consumption of NSAIDs. Side-effects after GP-C (14.5%) were rare, mild and not more frequent than in the placebo group (15%).Conclusion We were not able to demonstrate a structure modifying effect of GP-C in OA of the hip or knee. Radiographic progression of OA in both knee and hip OA was lower than expected in both study groups.