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1.
Neuropediatrics ; 52(5): 383-389, 2021 10.
Article in English | MEDLINE | ID: mdl-33511594

ABSTRACT

BACKGROUND: Cerebral palsy (CP) is the most common motor impairment in childhood and often accompanied by a broad spectrum of comorbidities. Data are sparse concerning visual impairment (VI) and functional classification among CP children. OBJECTIVE: The objective of this study was to analyze the prevalence of VI among children with CP and to investigate a possible association between VI and Gross Motor Function Classification System (GMFCS) and the Bimanual Fine Motor Function (BFMF). METHODS: In this hospital-based study, records of 200 children with CP aged 2 to 17 years were reviewed. RESULTS: Overall, VI was found in 59.5% of children with CP. Prevalence of VI was higher when compared with non-CP children. A correlation between GMFCS as well as BFMF and severity of VI was found. Children with severe CP were at greater risk for severe VI, especially cerebral VI compared with children with mild CP. CONCLUSION: VI is a significant problem in children with CP and is correlated with motor function. Children with CP should undergo detailed ophthalmologic and orthoptic assessment to enable early intervention.


Subject(s)
Cerebral Palsy , Adolescent , Cerebral Palsy/complications , Cerebral Palsy/epidemiology , Child , Child, Preschool , Comorbidity , Humans , Severity of Illness Index , Vision Disorders/epidemiology , Vision Disorders/etiology
2.
Arch Orthop Trauma Surg ; 140(11): 1837-1845, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32951060

ABSTRACT

PURPOSE: Polyethylene (PE) wear remains a common reason for revision surgery following total hip arthroplasty (THA). An established treatment method is isolated liner exchange in a well-fixed acetabular cup and entails a known high risk of hip dislocation after revision surgery. The purpose of this retrospective study was to determine the rate of hip dislocation after liner exchange. METHODS: Patients were included if (1) the PE liner was removable, (2) the acetabular shell was stable with acceptable orientation, (3) no osteolysis around the acetabular cup was found and (4) no dislocation of the THA occurred before revision surgery. We reviewed medical histories and performed radiological measurements using Einzel-Bild-Röntgen-Analyse (EBRA) software. EBRA measurements and statistical investigations were performed by two independent investigators. RESULTS: A total of 82 patients were included in our study. Mean follow-up was six (range: 3.6-9.9) years. In 13 (15.8%) patients THA dislocations occurred at a mean postoperative period of 20.2 (range: 1-44) weeks after revising the PE liner. This is equivalent to an absolute risk increase of 16% after revision surgery, which results in a number needed to harm of 6. This means that every sixth patient with isolated liner exchange can expect to experience dislocation due to wear. CONCLUSION: In conclusion, isolated exchange of the polyethylene liner because of wear showed a high risk of dislocation and further cup revision. Our results suggest that the threshold for revising well-fixed components in the case of liner wear should be lowered. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: Number: 20140710-1012 and Date: 2016-03-09.


Subject(s)
Arthroplasty, Replacement, Hip , Hip Dislocation , Hip Prosthesis/adverse effects , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Hip/instrumentation , Hip Dislocation/epidemiology , Hip Dislocation/etiology , Humans , Polyethylene/therapeutic use , Prosthesis Design , Prosthesis Failure , Retrospective Studies
3.
Bone Joint J ; 100-B(10): 1399-1404, 2018 10.
Article in English | MEDLINE | ID: mdl-30295526

ABSTRACT

AIMS: The purpose of this study was to analyze the incidence of the different ultrasound phenotypes of developmental dysplasia of the hip (DDH), and to determine their subsequent course. PATIENTS AND METHODS: A consecutive series of 28 092 neonates was screened and classified according to the Graf method as part of a nationwide surveillance programme, and then followed prospectively. Abnormal hips were followed until they became normal (Graf type I). Type IIb hips and higher grades were treated by abduction in a Tübinger orthosis until normal. Dislocated hips underwent closed or open reduction. RESULTS: Overall, 90.2% of hips were normal at birth. Type IIa hips (8.9%) became normal at a median of six weeks (interquartile range (IQR) 6 to 9). Type IIc and IId hips (0.67%) became normal after ten weeks (IQR 7 to 13). There were 19 type lll and eight type lV hips at baseline. There were 24 closed reductions and one open reduction. No late presentations of DDH were detected within the first five years of life. CONCLUSION: The incidence of DDH was eight per 1000 live births. The treatment rate was 1% (n = 273). The rate of first operations on the newborn hip was 0.86, and rate of open surgery was 0.04. The cumulative rate of open surgery was 0.07. The authors take the view that early identification and treatment in abduction of all dysplastic hips in early childhood reduces the rate of open reduction and secondary DDH-related surgery later in life. Cite this article: Bone Joint J 2018;100-B:1399-1404.


Subject(s)
Hip Dislocation, Congenital/diagnostic imaging , Neonatal Screening/methods , Austria/epidemiology , Female , Follow-Up Studies , Hip Dislocation, Congenital/epidemiology , Hip Dislocation, Congenital/therapy , Humans , Incidence , Infant, Newborn , Male , Prospective Studies , Ultrasonography
4.
J Child Orthop ; 12(4): 296-301, 2018 Aug 01.
Article in English | MEDLINE | ID: mdl-30154918

ABSTRACT

PURPOSE: To summarize recent developments and provide recommendations as to whether universal or selective programmes are advisable. METHODS: A literature review was performed and preference given to studies with higher levels of evidence. All programmes reviewed included clinical screening. RESULTS: Recent studies underline the need for high quality screening programmes to promote the early detection of developmental dysplasia of the hip (DDH). A small number of cases may be missed clinically but with universal ultrasound screening programmes the late presentation rates appear to be virtually zero. Contemporary studies show treatment rates with universal screening programmes which are now lower than those with selective ultrasound. There is little agreement over the criteria used for selective programmes. Alternative outcome measures, such as the first operation rate or the percentage undergoing major (open) surgery are both lowest with universal ultrasound screening programmes. Furthermore, a significant reduction in the rate of surgery for DDH later in life was seen after the introduction of universal ultrasound screening, whereas the defined criteria for selective screening may not detect the majority of patients who require late surgery. Abduction bracing with modern orthoses is associated with a zero rate of avascular necrosis (AVN), whereas closed reduction techniques have an overall risk of 10%. CONCLUSION: On clinical grounds, if future studies confirm that hip abduction in flexible orthoses is not associated with AVN, it may be time for a paradigm shift of screening for DDH towards a universal ultrasound protocol. The costs associated both with each type of screening programme and with the management of late presenting cases are also important but may be secondary to clinical benefit.

5.
Orthopade ; 44(11): 909-13, 2015 Nov.
Article in German | MEDLINE | ID: mdl-26395449

ABSTRACT

BACKGROUND: An acute ligament rupture of the lateral ligament complex of the ankle joint is treated without surgery. Treatment failure may lead to a chronically unstable situation of the ankle joint, in which case surgery is an effective procedure for stabilizing the ruptured ligaments. Anatomical reconstruction is the best operative technique if the ligament tissue is of good quality. METHOD: In our video we demonstrate a new possibility for the positioning of an anchor to tighten the calcaneo-fibular ligament. Modified Broström repairs are described in the literature in which the calcaneo-fibular ligament is released and reattached to the fibula to tighten it. We present the option to release the ligament at the calcaneus and reattach it using a suture anchor. This offers the advantage of preventing the possible dislocation of the peroneal tendons.


Subject(s)
Ankle Joint/surgery , Calcaneus/surgery , Joint Instability/surgery , Lateral Ligament, Ankle/surgery , Plastic Surgery Procedures/methods , Suture Techniques , Chronic Disease , Humans , Minimally Invasive Surgical Procedures/methods , Treatment Outcome
6.
Orthopade ; 43(7): 603-10, 2014 Jul.
Article in German | MEDLINE | ID: mdl-25100286

ABSTRACT

BACKGROUND: Spina bifida is associated with congenital deformities, such as kyphosis, spinal malformations, teratological hip dislocations, clubfeet, vertical talus and also with acquired deformities due to muscle imbalance and impaired biomechanics. The degree of the acquired deformities and the mobility of the patient depend on the level of the spinal lesion. DIAGNOSTICS: Neurological symptoms are mostly asymmetric and there is an inconsistent correlation between the anatomical level of the lesion and muscle function. Deficits of sensation are usually one to two levels lower than the motor level. An exact neurological diagnosis should not be made before the second or third year of life and an early prognosis about walking ability should be avoided. The level L3 and therefore function of the quadriceps is a functional milestone after which modified independent ambulation with the use of ankle foot orthoses (AFO) and crutches is possible. THERAPY: The basic principle is to support verticalization and gait even when loss of ambulation is later expected. It is also important to support and maintain sitting ability for high lesions, if necessary with correction of the spinal deformity. Findings in gait analysis have shifted the focus of treatment from radiological criteria to functional improvement, thus maintenance of the flexibility of the hip is the main goal of hip surgery. Reduction of the hip often leads to stiffness and has a high redislocation rate. Clubfoot deformities should be treated early and foot arthrodesis and stiffness have to be avoided. Another focus is the prevention of joint contracture by early prophylactic treatment. CONCLUSION: The purpose of management is to maximize the functional potential of the child. Subjective well-being, absence of pain, mobility and socialization are the main goals. This does not necessarily imply ambulation; nevertheless, verticalization and associated orthotic management is one major objective of the orthopedic management of spina bifida.


Subject(s)
Spinal Dysraphism/surgery , Child , Child, Preschool , Clubfoot/diagnosis , Clubfoot/surgery , Contracture/diagnosis , Contracture/physiopathology , Contracture/surgery , Female , Gait Disorders, Neurologic/diagnosis , Gait Disorders, Neurologic/physiopathology , Gait Disorders, Neurologic/surgery , Hip Dislocation, Congenital/diagnosis , Hip Dislocation, Congenital/physiopathology , Hip Dislocation, Congenital/surgery , Humans , Infant , Infant, Newborn , Neurologic Examination , Posture/physiology , Pregnancy , Prenatal Diagnosis , Prognosis , Quality of Life , Range of Motion, Articular/physiology , Spinal Dysraphism/diagnosis , Spinal Dysraphism/physiopathology
7.
J Bone Joint Surg Br ; 93(8): 1126-30, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21768641

ABSTRACT

Between 1978 and 1997 all newborns in the Austrian province of Tyrol were reviewed regarding hip dysplasia and related surgery. This involved a mean of 8257 births per year (7766 to 8858). Two observation periods were determined: 1978 to 1982 (clinical examination alone) and 1993 to 1997 (clinical examination and universal ultrasound screening). A retrospective analysis compared the number and cost of interventions due to hip dysplasia in three patient age groups: A, 0 to < 1.5 years; B, ≥ 1.5 to < 15 years; and C, ≥ 15 to < 35 years. In group A, there was a decrease in hip reductions from a mean of 25.2 (SD 2.8) to 7.0 (SD 1.4) cases per year. In group B, operative procedures decreased from a mean of 17.8 (SD 3.5) to 2.6 (SD 1.3) per year. There was a 75.9% decrease in the total number of interventions for groups A and B. An increase of €57,000 in the overall cost per year for the second period (1993 to 1997) was seen, mainly due to the screening programme. However, there was a marked reduction in costs of all surgical and non-surgical treatments for dysplastic hips from €410,000 (1978 to 1982) to €117,000 (1993 to 1997). We believe the small proportional increase in costs of the universal ultrasound screening programme is justifiable as it was associated with a reduction in the number of non-surgical and surgical interventions. We therefore recommend universal hip ultrasound screening for neonates.


Subject(s)
Hip Dislocation, Congenital/diagnostic imaging , Neonatal Screening/economics , Austria/epidemiology , Cost-Benefit Analysis , Female , Health Care Costs/statistics & numerical data , Hip Dislocation, Congenital/economics , Hip Dislocation, Congenital/epidemiology , Hip Dislocation, Congenital/surgery , Humans , Infant, Newborn , Male , Neonatal Screening/methods , Orthopedic Procedures/economics , Orthopedic Procedures/statistics & numerical data , Orthopedic Procedures/trends , Physical Examination/economics , Retrospective Studies , Ultrasonography/economics
8.
J Child Orthop ; 5(5): 343-9, 2011 Oct.
Article in English | MEDLINE | ID: mdl-23024725

ABSTRACT

PURPOSE: Evaluation of the advantages and limitations of the Taylor Spatial Frame (TSF) with regard to the healing index (HI), distraction-consolidation time (DCT), accuracy of correction complications, and cost of the device. METHODS: Comparison of results with the traditional Ilizarov apparatus and a unilateral Orthofix fixator in a consecutive patient series with 135 bony deformity corrections. RESULTS: The HI did not differ significantly between all three fixators and was 57 days/cm for all patients. The DCT was significantly shorter for the TSF (148 days) compared to the Ilizarov fixator (204 days) and the Orthofix device (213 days). The accuracy of deformity correction was higher for the TSF than the other devices. The mean values of the measured angles after correction did not differ, but the variance of the results was the lowest. Also, the total rate of complications was considerably lower for the TSF. The Orthofix device showed a high rate of angular deformity during treatment, whereas both ring fixators had a relatively higher number of pin-related problems. CONCLUSIONS: The findings in our patient series suggest the use of the Orthofix apparatus for simple lengthening over short to median distances and the Ilizarov device for the correction of simple bony deformities and pure lengthening over long distances. The TSF allows multiplanar corrections and lengthenings without complex modifications of the device. But, due to the remarkably higher costs, it has not yet been established as our routine device. LEVEL OF EVIDENCE: Level IV-case series. Therapeutic Study-Investigating the Results of Treatment.

9.
Int Orthop ; 32(5): 611-7, 2008 Oct.
Article in English | MEDLINE | ID: mdl-17579861

ABSTRACT

Periacetabular osteotomy (PAO) is a well established method to treat hip dysplasia in the adult. There is, however, a lack of information on the subjective outcome of patients with complications after PAO. The purpose of this study was therefore to assess the influence of complications on the patients' post-operative wellbeing and function: 60 PAOs on 50 patients were investigated retrospectively after a mean follow-up of 7.4 years. The patients' self-reported assessment of health and function was evaluated by the Medical Outcomes Short Form-36 (SF-36) and the Western Ontario and McMaster Universities (WOMAC) questionnaires at last follow-up. Forty healthy persons served as a control group. Of the 60 interventions 13 had no complications. Minor complications occurred in 25 (41%) and in 22 (37%) at least one major complication occurred. SF-36 summary measure was 76.4 for PAO patients and 90.3 for the control group. Mean WOMAC score was 25.1. Patients with major complications had a similar subjective outcome as patients with minor or without complications, but persistent dysaesthesia due to lateral femoral cutaneous nerve dysfunction led to a worse subjective function. Lesions of the lateral femoral cutaneous nerve have much greater influence on patients' self-assessed functional outcome after PAO than previously reported and greater attention has to be given to this supposedly minor complication.


Subject(s)
Hip Dislocation/surgery , Pelvic Bones/surgery , Acetabulum/surgery , Adolescent , Adult , Child , Female , Health Status Indicators , Humans , Male , Middle Aged , Osteotomy , Patient Satisfaction , Young Adult
10.
Orthopade ; 35(7): 791-7, 2006 Jul.
Article in German | MEDLINE | ID: mdl-16586056

ABSTRACT

BACKGROUND: In a 28-year-old male who had suffered an olecranon fracture, delayed diagnosis was made of epithelioid sarcoma in the left upper extremity. Radical tumor resection was carried out which included removal of the entire elbow joint. MATERIAL AND METHODS: The amputated hand with the distal one-third of the forearm was replanted at the upper arm. It was important to ensure that all tendinous structures of the forearm were attached to the three muscles of the upper arm and the nerves of the distal forearm with the nerves of the upper arm, which are incongruent in diameter with the former. Details of the operation are given below. RESULTS: The anatomic peculiarities involved in this form of replantation, the early intensive therapy, reintegration of the replanted hand in the body scheme, and the usability of such a shortened extremity are described and the extremely good functional results documented in numbers and figures.


Subject(s)
Hand Transplantation , Neoplasms, Connective Tissue/surgery , Plastic Surgery Procedures/methods , Recovery of Function , Sarcoma/surgery , Transplantation, Heterotopic/methods , Upper Extremity/surgery , Adult , Humans , Male , Treatment Outcome
11.
Arch Orthop Trauma Surg ; 126(6): 387-93, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16557367

ABSTRACT

The aim of the present in vitro study was to evaluate migrational characteristics of cementless primary hip arthroplasty stems in combination with a diameter 50 mm head (hemiarthroplasty) and a diameter 28 mm head in and with a polyethylene cup (total hip arthroplasty) in fresh-frozen human specimens. Two different types (Endo SL, FMT) were implanted into seven pairs of fresh-frozen human femoral specimens. The implanted stems were combined with a diameter 50 mm head (hemiarthroplasty) on one side and with a polyethylene cup and a 28 mm head (total hip arthroplasty) on the other side. Dynamic mechanical loading was applied for 50,000 cycles while recording relative motions between stem and bone stock using a 3-D motion analysis system. The Endo SL stem showed a significantly higher amplitude of relative motion in all translational and rotational components regardless of the head used. In both stem types a strong tendency for higher axial migration with the diameter 50 mm head in comparison to the THA head was found. The lowest axial migration was found in the FMTstem in combination with the small head and a PE cup. The highest axial migration was found in the Endo SL stem combined with the diameter 50 mm head. Our results indicate that the head might play an important role for axial migration of cementless stems.


Subject(s)
Arthroplasty, Replacement, Hip/instrumentation , Hip Prosthesis , Prosthesis Failure , Biomechanical Phenomena , Humans , In Vitro Techniques , Motion , Prosthesis Design
12.
Arch Orthop Trauma Surg ; 126(6): 380-6, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16557369

ABSTRACT

Aim of the present study was to evaluate migration rates of cementless primary hemiarthroplasty in acute femoral neck fractures. In a longitudinal, prospective study 46 patients were treated by cementless hemiarthroplasty. Clinical follow up was correlated with the EBRA-FCA method. In 30% of all patients stem migration amounted to more than 2 mm; further, these patients were seen to have a high level of activity. A high degree of migration in more than 30% of all patients requires critical scepticism toward further use of the investigated cementless stem as hemiarthroplasty. According to literature, migration of more than 2 mm suggests a high probability of early aseptic loosening. In patients with a low degree of activity good results could be observed; nevertheless, in patients with a high level of activity the combination of the investigated cementless stem with a solid fracture head cannot be recommended.


Subject(s)
Arthroplasty, Replacement/methods , Femoral Neck Fractures/surgery , Prosthesis Failure , Aged , Aged, 80 and over , Arthroplasty, Replacement/instrumentation , Female , Humans , Longitudinal Studies , Male , Middle Aged , Motor Activity , Prospective Studies , Treatment Outcome
13.
J Bone Joint Surg Br ; 87(6): 762-9, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15911655

ABSTRACT

Malposition of the acetabular component is a risk factor for post-operative dislocation after total hip replacement (THR). We have investigated the influence of the orientation of the acetabular component on the probability of dislocation. Radiological anteversion and abduction of the component of 127 hips which dislocated post-operatively were measured by Einzel-Bild-Röentgen-Analysis and compared with those in a control group of 342 patients. In the control group, the mean value of anteversion was 15 degrees and of abduction 44 degrees. Patients with anterior dislocation after primary THR showed significant differences in the mean angle of anteversion (17 degrees), and abduction (48 degrees) as did patients with posterior dislocation (anteversion 11 degrees, abduction 42 degrees). After revision patients with posterior dislocation showed significant differences in anteversion (12 degrees) and abduction (40 degrees). Our results demonstrate the importance of accurate positioning of the acetabular component in order to reduce the frequency of subsequent dislocations. Radiological anteversion of 15 degrees and abduction of 45 degrees are the lowest at-risk values for dislocation.


Subject(s)
Acetabulum/pathology , Arthroplasty, Replacement, Hip/methods , Hip Dislocation/prevention & control , Postoperative Complications/prevention & control , Adult , Aged , Aged, 80 and over , Arthroplasty, Replacement, Hip/adverse effects , Cementation , Female , Hip Dislocation/etiology , Hip Prosthesis , Humans , Male , Middle Aged , Prosthesis Failure , Risk Factors
14.
J Bone Joint Surg Br ; 87(5): 741-4, 2005 May.
Article in English | MEDLINE | ID: mdl-15855382

ABSTRACT

Studies on the migration of an implant may be the only way of monitoring the early performance of metal-on-metal prostheses. The Ein Bild Roentgen Analyse--femoral component analysis (EBRA-FCA) method was adapted to measure migration of the femoral component in a metal-on-metal surface arthroplasty of the hip using standard antero-posterior radiographs. In order to determine the accuracy and precision of this method a prosthesis was implanted into cadaver bones. Eleven series of radiographs were used to perform a zero-migration study. After adjustment of the femoral component to simulate migration of 3 mm the radiographs were repeated. All were measured independently by three different observers. The accuracy of the method was found to be +/- 1.6 mm for the x-direction and +/- 2 mm for the y-direction (95% percentile). The method was validated using 28 hips with a minimum follow-up of 3.5 years after arthroplasty. Seventeen were sound, but 11 had failed because of loosening of the femoral component. The normal (control) group had a different pattern of migration compared with that of the loose group. At 29.2 months, the control group showed a mean migration of 1.62 mm and 1.05 mm compared with 4.39 mm and 4.05 mm in the failed group, for the centre of the head and the tip of the stem, respectively (p = 0.001). In the failed group, the mean time to migration greater than 2 mm was earlier than the onset of clinical symptoms or radiological evidence of failure, 19.1 versus 32.2 months (p = 0.001) and 24.8 months (p = 0.012), respectively. EBRA-FCA is a reliable and valid tool for measuring migration of the femoral component after surface arthroplasty and can be used to predict early failure of the implant. It may be of value in determining the long-term performance of surface arthroplasty.


Subject(s)
Arthroplasty, Replacement, Hip/methods , Hip Prosthesis , Adult , Aged , Bone Diseases/surgery , Cadaver , Equipment Failure Analysis/methods , Female , Femur/surgery , Hip Joint/surgery , Humans , Joint Diseases/surgery , Male , Middle Aged , Prosthesis Design , Prosthesis Failure , Reproducibility of Results , Software
15.
Int Orthop ; 29(1): 14-7, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15490162

ABSTRACT

We implanted 71 metal-backed, porous-coated, hemispheric, press-fit Duraloc-100 cups in 68 consecutive patients. In 61 patients, the femoral stem was a cementless Spotorno and in ten a cemented Lubinus SP II. A 28-mm Biolox ceramic head was used with both stems. After an average follow-up of 4 (3.7-5.9) years, we examined 67 hips. Radiolucencies were described in three zones according to DeLee and Charnley, and migration was measured on serial radiographs using the computer-assisted EBRA method. Total migration of more than 1 mm within the first 2 years occurred in 22/62 cups. Nine cups showed more than 1.5 mm total migration within the first 2 years and more than 2 mm within the whole period. The presence of post-operative radiolucencies correlated significantly with a total migration value of more than 2 mm within the first 2 years (p=0.02). Post-operative radiolucencies in zone 1 correlated with a total migration value of more than 2 mm within the first 2 years (p=0.027) and more than 2.5 mm within the whole period (p=0.051). These correlation values might reflect the quality of operative technique, particularly reaming, and implant selection.


Subject(s)
Hip Prosthesis , Osteoarthritis, Hip/diagnostic imaging , Osteoarthritis, Hip/surgery , Adult , Aged , Arthroplasty, Replacement, Hip , Chi-Square Distribution , Female , Follow-Up Studies , Foreign-Body Migration/diagnostic imaging , Humans , Male , Middle Aged , Prosthesis Design , Prosthesis Failure , Radiography , Statistics, Nonparametric
16.
Clin Orthop Relat Res ; (412): 103-10, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12838059

ABSTRACT

In a prospective randomized study, 32 metal-on-metal prostheses and 29 ceramic-on-polyethylene prostheses of similar design were implanted in 59 patients. Radiolucency, cup migration, wear, and function were examined after a minimum of 2 years followup (followup rate, 87%). The purpose of the current study was to evaluate whether higher frictional torque of metal-on-metal will lead to a higher rate of early metal-on-metal cup loosening. A computer-assisted method was used for wear and migration measurements of the acetabular component. Metal-on-metal prostheses migrated in a craniocaudad direction significantly less than ceramic-on-polyethylene prostheses. The mean total migration for both types of prostheses exceeded 1.5 mm at 2 years. Clinically, no difference between the two prostheses regarding activity, pain, or range of motion was found at 2 years. As migration of metal-on-metal prostheses was not higher in comparison with ceramic-on-polyethylene prostheses, the expected higher frictional torque of metal-on-metal prostheses did not increase migration during short-term followup. The different debris produced by both bearings did not influence the short-term results of this study, but might cause different long-term results.


Subject(s)
Ceramics , Hip Prosthesis , Metals , Polyethylene , Prosthesis Failure , Aged , Equipment Failure Analysis/methods , Female , Follow-Up Studies , Hip Joint/diagnostic imaging , Humans , Male , Middle Aged , Prospective Studies , Prosthesis Design , Radiography , Range of Motion, Articular
17.
J Bone Joint Surg Br ; 83(5): 767-71, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11476320

ABSTRACT

Our aim was to determine whether tantalum m arkers improved the accuracy and/or precision of methods for the measurement of migration in total hip replacement based on conventional measurements without mathematical correction of the data, and with Ein Bild Roentgen Analyse - Femoral Component Analysis (EBRA-FCA) which allows a computerised correction. Three observers independently analysed 13 series of roentgen-stereophotogrammetric-analysis (RSA)-compatible radiographs (88). Data were obtained from conventional measurements, EBRA-FCA and the RSA method and all the results were compared with the RSA data. Radiological evaluation was also used to quantify in how many radiographs the intraosseous position of the bone markers had been simulated. The results showed that tantalum markers improve reliability whereas they do not affect accuracy for conventional measurements and for EBRA-FCA. Because of the danger of third-body wear their implantation should be avoided unless they are an integral part of the method.


Subject(s)
Equipment Failure Analysis , Hip Prosthesis , Photogrammetry , Postoperative Complications/diagnostic imaging , Radiographic Image Interpretation, Computer-Assisted , Tantalum , Computer Simulation , Follow-Up Studies , Humans , Mathematical Computing , Predictive Value of Tests
18.
J Bone Joint Surg Br ; 81(2): 266-72, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10204933

ABSTRACT

Several methods of measuring the migration of the femoral component after total hip replacement have been described, but they use different reference lines, and have differing accuracies, some unproven. Statistical comparison of different studies is rarely possible. We report a study of the EBRA-FCA method (femoral component analysis using Einzel-Bild-Röntgen-Analyse) to determine its accuracy using three independent assessments, including a direct comparison with the results of roentgen stereophotogrammetric analysis (RSA). The accuracy of EBRA-FCA was better than +/- 1.5 mm (95% percentile) with a Cronbach's coefficient alpha for interobserver reliability of 0.84; a very good result. The method had a specificity of 100% and a sensitivity of 78% compared with RSA for the detection of migration of over 1 mm. This is accurate enough to assess the stability of a prosthesis within a relatively limited period. The best reference line for downward migration is between the greater trochanter and the shoulder of the stem, as confirmed by two experimental analyses and a computer-assisted design.


Subject(s)
Arthrography/methods , Arthroplasty, Replacement, Hip , Femur Head/diagnostic imaging , Hip Joint/diagnostic imaging , Hip Prosthesis/standards , Acetabulum/diagnostic imaging , Biomechanical Phenomena , Hip Joint/surgery , Humans , Observer Variation
19.
J Bone Joint Surg Br ; 81(2): 273-80, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10204934

ABSTRACT

We report the ten-year results for three designs of stem in 240 total hip replacements, for which subsidence had been measured on plain radiographs at regular intervals. Accurate migration patterns could be determined by the method of Einzel-Bild-Roentgen-Analyse-femoral component analysis (EBRA-FCA) for 158 hips (66%). Of these, 108 stems (68%) remained stable throughout, and five (3%) started to migrate after a median of 54 months. Initial migration of at least 1 mm was seen in 45 stems (29%) during the first two years, but these then became stable. We revised 17 stems for aseptic loosening, and 12 for other reasons. Revision for aseptic loosening could be predicted by EBRA-FCA with a sensitivity of 69%, a specificity of 80%, and an accuracy of 79% by the use of a threshold of subsidence of 1.5 mm during the first two years. Similar observations over a five-year period allowed the long-term outcome to be predicted with an accuracy of 91%. We discuss the importance of four different patterns of subsidence and confirm that the early measurement of migration by a reasonably accurate method can help to predict long-term outcome. Such methods should be used to evaluate new and modified designs of prosthesis.


Subject(s)
Arthrography/methods , Arthroplasty, Replacement, Hip , Femur Head/diagnostic imaging , Hip Joint/diagnostic imaging , Hip Prosthesis/standards , Acetabulum/diagnostic imaging , Biomechanical Phenomena , Equipment Design , Equipment Failure , Follow-Up Studies , Hip Joint/surgery , Humans , Prognosis
20.
J Bone Joint Surg Br ; 81(1): 51-3, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10068002

ABSTRACT

We carried out 71 primary total hip arthroplasties using porous-coated, hemispherical press-fit Duraloc '100 Series' cups in 68 consecutive patients; 61 were combined with the cementless Spotorno stem and ten with the cemented Lubinus SP II stem. Under-reaming of 2 mm achieved a press-fit. Of the 71 hips, 69 (97.1%) were followed up after a mean of 2.4 years. Migration analysis was performed by the Ein Bild Rontgen Analyse method, with an accuracy of 1 mm. The mean total migration after 24 months was 1.13 mm. Using the definition of loosening as a total migration of 1 mm, it follows that 30 out of 63 cups (48%) were loose at 24 months.


Subject(s)
Foreign-Body Migration , Hip Prosthesis , Osteoarthritis, Hip/surgery , Prosthesis Failure , Adult , Aged , Female , Humans , Male , Middle Aged
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