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.

We aimed to investigate the clinical consequences of intraoperative acetabular fractures. Between 2003 and 2012, a total of 3391 cementless total hip arthroplasties (THA) were performed at the Dept. of Orthopaedics, Innsbruck Medical University. Of those, a total of 160 patients underwent a CT scan within 30 days postoperatively. The scans of 44 patients were not suitable for analyse due to thick scan layers. Of the remaining 116 patients, 76 had a fracture. Reasons for CT-scans were suspected bleeding, hip pain, abdominal symptoms, etc.

The fractures included 59 isolated acetabular fractures, the rest of fractures was in the superior or inferior pubic ramus or the tuber ischiadicum.

Four cases out of the 59 acetabular fractures underwent revision surgery due to periprosthetic joint infection after 0, 2, 10 and 23 months. Four patients underwent revision due to cup loosening after 13 and 14 days as well as after 16 and 24 months. Of those, three showed a central acetabular fracture with protrusion.

In 33 of the remaining 51 patients, a minimum of 3 x-rays was available for migration analysis with EBRA. In 6 patients, the x-rays were not comparable to each other. The 27 remaining acetabular fractures were categorised according to AO classification in 62A1 (1; posterior wall), 62A2 (16; posterior column), 62A3 (6; anterior wall), and others (4). Four hips showed initial migration of more than 3 mm in the first 6 months. One had a central fracture, and was lost for follow-up after 8 months. Two had an anterior column fracture and showed no further migration after 6 months. One showed also a radiolucency of more than 2 mm in all 3 zones and was lost for follow-up.

We conclude that intraoperative acetabular fractures occur more often than we expected. Fractures of the acetabular ring involving one column do not seem to compromise the long-term stability of the implant. Central fractures required revision or showed loosening proved by high cup migration.

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.

Objective: The aim of this study was to show the effect of a universal (all neonates) ultrasound screening in newborns on the incidence of operative treatment of hip dysplasia.

Materials: A retrospective study was performed and all newborns of the county Tyrol (Austria) between 1978 and 1998 (8257 births / year ((range: 7766 – 8858)) were reviewed regarding hip dysplasia and following hip surgeries. Between 1978 and 1983 clinical examination alone was performed to detect hip dysplasia. Between 1983 and 1988 an ultrasound screening programme according to Graf was initiated in our county. Between 1988 and 1998 ultrasound screening was performed in all newborns. Hence two observation periods were determined: 1978–1983 and 1993–1998. The time period between 1983 and 1993 was excluded to minimize bias and learning curve regarding the initiation of the ultrasound screening programme. A retrospective comparative analysis of the two observation periods regarding surgical treatment and costs caused by hip dysplasia was performed. During the observation period indication for surgery did not change, however new treatment techniques were introduced. Patients with neuromuscular and Perthes diseases were excluded. According to age dependent surgical procedures three patient samples were determined: Group A: 0–1.5 years, Group B: 1.5–15 years and Group C: 15–35 years.

Results: Comparison of the two observation periods showed no influence on the number of interventions for dysplastic hips in group C (pelvic osteotomies and VDROs). In group A, a decrease of hip reductions was seen from 25.6±3.2 to 7.0± 1.4 cases per year. In group B, there was a decrease of operative procedures for dysplastic hips from 18.0±3.2 to 3.4±1.3 interventions per year. Since the introduction of universal hip ultrasound screening the decrease of the total number of interventions for all groups was 78.6%. Comparison of costs of the two observation periods showed an increase of all costs caused by DDH and CDH of 57.000 euro/ year for the time period between 1993 and 1998 which was mainly caused by the ultrasound screening programme. There was a significant reduction of costs regarding operative and non operative treatment for dysplastic hips from 410.000 euro (1978–1983) to 117.00 euro (1993–1998).

Conclusion: Initially there were higher costs caused by the screening method, but on the other hand total number and costs for operative and nonoperative treatment of dysplastic hips were significantly reduced by the universal ultrasound screening programme. In our mind patient’s and family distress and pain related to interventions performed for CDH and DDH justify the slight increase of costs caused by the universal screening programme. We therefore recommend universal hip ultrasound screening for neonates.

After catastrophic failure of first generation, joint replacement as treatment option for ankle osteoarthritis is undergoing a revival with improved second generation designs. Short to mid-term results reportedly equal those of ankle arthrodesis in terms of complications and revision, but preserving joint motion and protecting neighbouring midfoot joints from overuse and consecutive osteoarthritis. However, most reports derive from developers centres excluding the learning curve. We present clinical results and subjective outcome of an initial patient series undergoing ankle replacement in an independent centre.

From January 2004 to January 2008 a Hintegra^® prosthesis was implanted in 39 consecutive patients (41 ankles), average age 60.7 years (range 36.6–85.0), 13 males and 25 females. Repeated clinical follow up was done for an average of 2.2 years (range 0.5–4.3). All patients whose operation had been more than 0.7 years before were sent the FAOS (Foot and Ankle Outcome Score) in order to record the subjective outcome. Pre-operative diagnoses were posttraumatic osteoarthritis in 26 cases (63.4%), primary osteoarthritis in 9 cases (22%) and rheumatoid arthritis in 6 cases (14.6%).

Clinical examination did not show significant improvement of mean range of motion, dorsiflexion and plantarflexion compared with the preoperative status. The change in motion highly correlated with the preoperative mobility (r=0,8; p< 0.001): patients with the largest preoperative range of motion were the ones to lose most mobility, whereas patients with low preoperative motion gained mobility. About 60% of the patients achieved 25° to 30° total range of motion regardless of their preoperative mobility. Early postoperative complications occurred in 14 patients (34.1%). In all five subclasses of the FAOS a significant improvement was achieved within the observation period. Reduction of pain had the greatest impact on the improvement of quality of life, whereas change in mobility did not have any influence.

Joint replacement is a valuable treatment option for ankle osteoarthritis. There are however a series of early complications and restrictions of subjective outcome a surgeon has to be aware of when selecting an individual patient for ankle replacement. Further studies are needed to detect in which cases arthrodesis or prosthesis is preferable.

Periacetabular osteotomy (PAO) is a well established method to treat hip dysplasia in the adult. There are, however, a number of complications associated with this procedure as well as a time related deterioration in the grade of osteoarthritis that can influence the long term result. It is essential that patients are fully informed as to the effectiveness of PAO, the likelihood of complications and their influence on the subjective outcome prior to giving consent for surgery. Generic outcome measures offer the opportunity to determine treatment efficacy and the influence on the outcome by complications.

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 SF-36 and the WOMAC questionnaires at last follow-up. 40 healthy persons served as a control group.

The centre-edge angle improved from a mean of 8.7° to 31.5°. The weight bearing surface improved from a mean lateral opening of 8.7° to 4.2°. The degree of osteoarthritis improved in one case, remained unchanged in 20 and deteriorated in 17. There was a tendency of higher CE-angles towards a higher rate of deterioration, indicating that overcorrection may increase osteo-arthritic degeneration. 13 of the 60 interventions had no complications. Minor complications occurred in 25 (41%) interventions 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. The severity of ectopic bone formation, incidence of postoperative peroneal nerve dysfunction and delayed wound closure did not influence the subjective result. Patients with major complications had a similar subjective outcome as patients with minor or no complications, but persistent dysesthesia due to lateral femoral cutaneous nerve dysfunction led to a worse subjective function as assessed with the WOMAC score.

Study Design. Retrospective clinical and radiographic review of patients after Bernese periacetabular osteotomy for symptomatic congenital hip dysplasia. Introduction. The Bernese periacetabular osteotomy for the treatment of symptomatic congenital hip dysplasia is known to be a complex operative procedure. Several authors reported significant percentages of peri- and postoperative complications.

Objective.The aim of our study was to reveal whether the incidence as well as the grade of complications affect the postoperative outcome which was determined by the short form (SF) 36 and the Western Ontario McMasters osteoarthritis (WOMAC) questionnaires.

Methods. A consecutive series of 50 patients with 60 hips operated between 1988 and 2000 were investigated retrospectively with a mean follow up period of 32 months.

Results. With an incidence of 30% a lesion of the lateral cutaneus nerve occurred. In 10% a peroneal nerve palsy was diagnosed immediate postoperatively, with 4% persistent neurological deficit presented at one year follow up. Several other minor and major complications occurred with an overall complication rate of 68%. According to the severity of complications two groups of patients were identified. Statistical analysis did not reveal any difference between the results of the SF-36 (p=0.2) and WOMAC (p=0.09) questionnaires. Radiological analysis revealed a deterioration of osteoarthritis in 32% of our patients. These patients predominantly judged their postoperative results poor to fair (r=0.71). 76% rated the operation as successful and 64% would have surgery again. The subjective estimation of patients health status postoperatively was significantly reduced compared to an age matched healthy reference group (p=0.0001).

Conclusion. Despite the high incidence of complications 76% of the patients rated the operation as successful. 32% of the patients faced a deterioration of osteoarthritis. The postoperative results after Bernese periacetabular osteotomy are rather more influenced by the progression of osteoarthritis than by the occurrence of perioperative complications.

The implementation of standards for deformity correction planning of axial deformities and leg length discrepancy in paediatric orthopaedics and posttraumatic cases have improved the results of postoperative alignment and joint orientation. A variety of externally and internally applicable devices have been developed for limb lengthening and deformity correction. One of the most recent developments is the Taylor Spatial Frame Fixator based on a hexapod system and a computer software for deformity correction. But little is published about clinical results using this sophisticated technique and its possible advantages over other traditional unilateral fixators or ring systems. In times of difficulties financing our health care systems, a surgeons choice for a comparatively costly system should be based on qualified data. The aim of the present study was to compare the results of deformity correction and limb lengthening using a Taylor Spatial Frame with those of other ring fixators or unilateral systems.

Between 1996 and 2004, 72 deformity corrections and/or limb lenghtenings have been performed on 52 patients with the unilateral Orthofix system (n=32), the Ilizarov system (n=22) and the TSF device (n=18). Statistical analysis showed a direct correlation between the healing index and the age at operation, as well as between the lengthening distance and the rate of complications. There were no significant differences of the healing index between all three fixators and the number of complications between the Ilizarov and TSF device, but the unilateral Orthofix fixator showed significantly more axial deviations during distraction osteogenesis.

The Taylor Spatial Frame is easier to handle than the Ilizarov fixator but did not show superior results in clinical use.

Component migration after THR is directly correlated with loosening and reported to be predictive for the long-term survival rate. In literature, four different patterns of stem-migration are reported. Likewise, periprothetic osteolytic zones indicate the risk of loosening and revision in the further course. Nevertheless, little is known about the distinguish migration behaviour between cemented and uncemented stems throughout the process of loosening. The aim of this study was to evaluate the influence of cementing on migration behaviour of loose femoral components after THR. A total of 207 stem-revisions have been performed at our institution between 1996 and 2001. Only patients with aseptic loosening after primary hip replacements were included in the present study. Thus, 75 patients had to be excluded due to other reasons for loosening. Migration analysis was done with the EBRA-FCA method (Einzel-Bild-Röntgen-Analyse, Femoral Component Analysis). In addition, a radiographic analysis was performed following Gruen et al. For migration analysis, a minimum of four x-rays per series are required. Hence, another 72 patients had to be excluded due to insufficient x-ray documentation. A total of 40 cemented (Group A) and 20 uncemented (Group B) femoral components could be analysed. There were no significant differences between the two groups with regard to age (60 years for Group A, 56 years for Group B), gender or side. Mean number of radiographs per series was 7.2 for Group A and 7.9 for Group B respectively. Mean stem survival differed between the two groups (11.3 years for Group A and 8.8 years for Group B), but without statistical significance (T-Test: p> 0.05). Differences in migration behaviour and distinct types of loosening after cemented and uncemented total hip replacement will be presented.

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° and of abduction 44°. Patients with anterior dislocation after primary THR showed significant differences in the mean angle of anteversion (17°), and abduction (48°) as did patients with posterior dislocation (anteversion 11°, abduction 42°). After revision patients with posterior dislocation showed significant differences in anteversion (12°) and abduction (40°).

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° and abduction of 45° are the lowest at-risk values for dislocation.

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.

Aims: A review of the existing literature is presented and compared with the results of a cohort study. These data are compared with the natural course of fracture healing. Methods: In a prospective cohort study 56 patients with nonunions and 14 patients with delayed unions after fracture or osteotomy were treated with shock wave therapy and followed for 2 years or to consolidation. These results and the previous data were assembled and were compared with the results of three studies on the natural course of fracture healing. Results: Consolidation was seen in 56% of patients with nonunions after a mean of 5.2 months, and in 93% of patients with delayed unions. The success rate of shock wave therapy was strongly associated with the time between primary diagnosis and shock wave therapy. Discussion: The success rate in the own cohort was quite similar to the results reported in the literature, after 3 months 52%, 41%, 19%, 40% or 25%, and 41%, 67%, 61% or 38% after 6 months respectively. At 12 months, healing occurred in up to 80%. The fractures were usually immobilised until union was assessed. It is not likely that a single intervention of shock wave therapy causes effects that last for several months. The results were compared with the natural course of fracture healing, also showing a time dependend healing rate. Conclusion: A considerable part of the effect of shock wave therapy may be attributed to the natural course of fracture healing, where healing is seen even after 6 or 12 months. Only a randomised study will be able to show whether shock wave therapy has any effect on fracture healing.

Aims: Postoperative dislocation of the implant is still an unsolved problem in THR. Malposition of the socket is reported to be one major risk factor. The aim of this study was to investigate the inßuence of cup orientation on the probability of postoperative prosthetic dislocation. Methods: The orientation of the socket was studied in 137 patients with postoperative dislocations, and compared with a control group (n=342). The EBRA-method (Ein-Bild- Roentgen-Analyse) was used to determine anteversion and inclination angles of the cups. A previous study showed that the precision of the method for measuring these parameters was ± 1degree (SD 0.33). Results: Mean values for the orientation of the prosthetic cup in the control group was 44¡ for inclination and 15¡ for anteversion. Patients with anterior dislocations after primary hip replacements showed signiþcant differences of the mean inclination (48¡, Mann-Whitney-Test: p=0.045) and anteversion angle (17¡, p=0.015). For posterior dislocations, mean inclination was 42¡ (p=0.277) and anteversion 11¡ (p=0.002) respectively. After revision hip arthroplasty, only patients with posterior dislocation of the implant showed signiþcant differences of the cup orientation (inclination: 40¡, p=0.03; anteversion:12¡,p=0.017). Conclusions: The results demonstrate the importance of accurate positioning of the socket to minimise the risk of subsequent dislocation. An anteversion of 15¡ and an inclination of 44–45¡ has the lowest at risk for dislocation.

Aims: Nonunion still remains a major complication after skeletal trauma or elective surgery. In the last decade, extracorporeal shock wave therapy has become a common tool for treatment of nonunions and was even referred to as treatment of þrst choice for this condition. But so far, no prospective, randomised trial was conducted to show efþciency of this form of treatment. Methods: This study was performed to determine the value of extracorporeal shock wave therapy for the treatment of nonunions. Previous published results in literature and own clinical results of 73 consecutive patients with nonunions, treated with extracorporeal shock waves, were analysed and confronted with natural history of union. Results: Concordant to literature, union was achieved in more than 55% of treated patients; better results were achieved for hypertrophic type of nonunion (61.8%). Mean time between shock wave therapy and bony consolidation was 5.3 months, ranging from 1 to 16.5 months. Conclusions: No study could prove efþciency of extracorporeal shock wave therapy on bone healing. Clinical studies, reporting acceleration of union after application of shock waves, rather seem to misinterpret natural history of union. No evidence is given for treatment of pseudarthroses with extracor-poreal shock waves. A randomised prospective clinical trial with control group has to be performed to take a þnal decision about this indication for extracorporeal shock wave therapy.

Our aim was to determine whether tantalum markers 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.

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.

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.

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 Röntgen 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.