Mathematical estimation of stress distribution in normal and dysplastic human hips

Mavčič, Blaž; Pompe, Borut; Antolič, Vane; Daniel, Matěj; Iglič, Aleš; Kralj‐Iglič, Veronika

doi:10.1016/s0736-0266(02)00014-1

Cited by 95 publications

(45 citation statements)

References 29 publications

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“…The mechanical parameters were estimated from AP pelvic radiographs with a previously developed analytical three-dimensional model (Iglič et al 1993a, b, Ipaveč et al 1999, Mavčič et al 2002) that corresponds to the static one-legged stance. The one-legged stance is considered to be the representative position for slow gait, as the most frequent activity in everyday life (McLeish and Charnley 1970).…”

Section: Clinical Radiographic and Mechanical Evaluationmentioning

confidence: 99%

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7–15-year follow-up of 26 hips

et al. 2005

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Background The Bernese periacetabular osteotomy is used in dysplastic hips to increase the load-bearing area of the hip and to prevent osteoarthritis.The aim of our work was to determine the contact hip stress before and after the osteotomy and to compare the relief of stress with the long-term radiographic and clinical outcome.Patients and methods We followed 26 dysplastic hips (26 patients) for 7-15 years after the index operation. Clinical evaluation was based on the WOMAC score, osteoarthrosis was evaluated with the Tönnis classification, the angles of lateral (CE) and anterior (VCA) femoral coverage were measured, and biomechanical parameters were studied.Results Periacetabular osteotomy increased the mean CE from 15° to 37°, and the mean VCA from 22° to 38°. The mean normalized peak contact stress was reduced from 5.2 to 3.0 kPa/N. Four hips required total hip arthroplasty after an average of 4.5 years, 8 hips showed considerable arthrosis progression, and 14 hips had no or mild arthrosis at follow-up. Preoperative WOMAC score, preoperative Tönnis grade and postoperative normalized peak contact stress were the most important predictors of outcome.Interpretation The Bernese periacetabular osteotomy improves the mechanical status of the hip. Long-term success depends on the grade of arthrosis preoperatively and on the magnitude of operative correction of the contact hip stress.

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Section: Clinical Radiographic and Mechanical Evaluationmentioning

confidence: 99%

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7–15-year follow-up of 26 hips

et al. 2005

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“…The peak contact stress was determined with the HIP-STRESS method based on a 3-D mathematical model of the resultant hip joint force in the one-legged stance [14] and of the contact stress [15,25]. The HIPSTRESS method can be applied by using data from anteroposterior pelvic radiographs as an input.…”

Section: Methodsmentioning

confidence: 99%

“…The error in estimating the peak contact stress due to estimated error in determination of geometrical parameters amounts to approximately 10% The differences between proportions of female hips, right-sided hips, and asymptomatic hips at followup and hips with THA at followup were tested with Fisher's exact test; values of continuous numeric variables are reported as mean ± standard deviation followed by range in the parentheses and significance with the two-sided unpaired Student's t-test; the Kellgren-Lawrence grade at followup is reported for 23 hips in the study group and six hips in the control group with available radiographs. [25]. We manually measured the following radiographic parameters from anteroposterior pelvic radiographs [25]: the interhip distance (l), the pelvic height (H), the pelvic width laterally from the femoral head center (C), the coordinates of the insertion point of abductors on the greater trochanter (point coordinates T x and T z in the frontal plane), the radius of the femoral head (r), and the Wiberg center-edge angle (0 CE ).…”

Section: Methodsmentioning

confidence: 99%

“…[25]. We manually measured the following radiographic parameters from anteroposterior pelvic radiographs [25]: the interhip distance (l), the pelvic height (H), the pelvic width laterally from the femoral head center (C), the coordinates of the insertion point of abductors on the greater trochanter (point coordinates T x and T z in the frontal plane), the radius of the femoral head (r), and the Wiberg center-edge angle (0 CE ). The 3-D reference coordinates of the muscle attachment points were taken from Dostal and Andrews [8] and adjusted by linear scaling with regard to the radiographic pelvic parameters (l, C, H, T x , T z ) for each individual hip.…”

Section: Methodsmentioning

confidence: 99%

“…Peak contact stress in the hip has been compared between different groups of patients with developmental dysplasia of the hip to evaluate outcomes of surgical procedures [12,37]. These and other experimental studies [29,36] and clinical reports [13,25] confirm patients with hip dysplasia have higher contact stress than healthy subjects.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Cumulative Hip Contact Stress Predicts Osteoarthritis in DDH

Mavčič

Iglič

Kralj‐Iglič

et al. 2008

Clinical Orthopaedics &Amp; Related Research

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Hip stresses are generally believed to influence whether a hip develops osteoarthritis (OA); similarly, various osteotomies have been proposed to reduce contact stresses and the risk of OA. We asked whether elevated hip contact stress predicted osteoarthritis in initially asymptomatic human hips. We identified 58 nonoperatively treated nonsubluxated hips with developmental dysplasia (DDH) without symptoms at skeletal maturity; the control group included 48 adult hips without hip disease. The minimum followup was 20 years (mean, 29 years; range, 20-41 years). Peak contact stress was computed with the HIPSTRESS method using anteroposterior pelvic radiographs at skeletal maturity. The cumulative contact stress was determined by multiplying the peak contact stress by age at followup. We compared WOMAC scores and radiographic indices of OA. Dysplastic hips had higher mean peak contact and higher mean cumulative contact stress than normal hips. Mean WOMAC scores and percentage of asymptomatic hips in the study group (mean age 51 years) were similar to those in the control group (mean age 68 years). After adjusting for gender and age, the cumulative contact stress, Wiberg center-edge angle, body mass index, but not the peak contact stress, independently predicted the final WOMAC score in dysplastic hips but not in normal hips. Cumulative contact stress predicted early hip OA better than the Wiberg center-edge angle.

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Finite element prediction of cartilage contact stresses in normal human hips

Harris

Anderson

Henak

et al. 2011

Journal Orthopaedic Research

183

169

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Our objectives were to determine cartilage contact stress during walking, stair climbing and descending stairs in a well-defined group of normal volunteers and to assess variations in contact stress and area among subjects and across loading scenarios. Ten volunteers without history of hip pain or disease with normal lateral center-edge angle and acetabular index were selected. Computed tomography imaging with contrast was performed on one hip. Bone and cartilage surfaces were segmented from volumetric image data, and subject-specific finite element models were constructed and analyzed using a validated protocol. Acetabular contact stress and area were determined for seven activities. Peak stress ranged from 7.52±2.11 MPa for heel-strike during walking (233% BW) to 8.66±3.01 MPa for heel-strike during descending stairs (261% BW). Average contact area across all activities was 34% of the surface area of the acetabular cartilage. The distribution of contact stress was highly non-uniform, and more variability occurred among subjects for a given activity than among activities for a single subject. The magnitude and area of contact stress were consistent between activities, although inter-activity shifts in contact pattern were found as the direction of loading changed. Relatively small incongruencies between the femoral and acetabular cartilage had a large effect on the contact stresses. These effects tended to persist across all simulated activities. These results demonstrate the diversity and trends in cartilage contact stress in healthy hips during activities of daily living and provide a basis for future comparisons between normal and pathologic hips.

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Mathematical estimation of stress distribution in normal and dysplastic human hips

Cited by 95 publications

References 29 publications

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7–15-year follow-up of 26 hips

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7–15-year follow-up of 26 hips

Cumulative Hip Contact Stress Predicts Osteoarthritis in DDH

Finite element prediction of cartilage contact stresses in normal human hips

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