Congenital Hip Dysplasia Research Articles

The role of ultrasonography in the diagnosis of gluteal muscle contracture

To evaluate the use of ultrasonography (US) in the diagnosis of gluteal muscle contracture (GMC) by analysis of its imaging characteristics. Thirty-nine patients suspected of having GMC due to abnormal gait underwent pre-operative US. The diagnosis of GMC was confirmed by surgery in 27 patients. Six patients were diagnosed with congenital hip dysplasia, and the remaining six patients were diagnosed with sciatic nerve damage, post-poliomyelitis sequelae, and myasthenia gravis. For the patients with GMC, US showed muscle thinning and hyperechoic strips (specific for muscular contracture) in the muscles involved. In three patients with GMC, the strips were integrated into muscle bundles, demonstrating both strong and weak sonographic echoes. The sensitivity and specificity of the diagnosis of GMC using the presence of strips were 88.9% and 83.3%, respectively, and using muscle thinning, the sensitivity and specificity were 92.6% and 50%, respectively. The contracture strips, as measured by US, were significantly smaller than the actual measurements at the time of surgery, but there was a significant correlation between the two measurements (r = 0.814, P < 0.01). The highest detection rate of GMC by US was found in the gluteus maximus muscle (91.8%), and the lowest rate was found in the piriformis muscle (52.9%). Ultrasonography is a valuable tool for the diagnosis of GMC, especially for the detection of specific contracture strips in involved muscles. Its role in the pre-operative diagnosis of GMC also provides surgical planning that can guide subsequent treatment.

Neonatal hip dysplasia: Differental diagnosis

Hip dysplasia is the elementary form of the developmental dysplasia of the hip (DDH). The diagnosis may be made by the ultrasound examination (types II a-, II b). The aim of the authors was to define the congenital structural neonatal hip dysplasia, and to differentiate hip hypoplasia, hip dysplasia and teratogenic anomalies. In all the cases, the uniform clinical and ultrasound tests were performed. All the patients were examined in the neonatal period of life (the first six weeks). The following clinical tests were used: Le Damany-Ortolany, Coleman-Barlow-Palmen and Weissman-Strinović. For the ultrasound examination, the Graph's method was used. The investigation was performed in the period 2007-2008. 2,878 neonates were included. The distribution of the sonotypes, according to Graph, was as follows: Ia in 16.17%. Ib in 65.08%; IIa+ in 18.17%, IIc in 0.28%, IId in 0.19%; IIIa in 0.009%, IIIb in 0.02%; and IV in 0.01%. It was found that DDH was 8 times more frequent in girls; located more frequently at the left side than bilaterally. Hip sonoscreening has to be performed in all newborns in the first 72 hours. The suggested follow-up period is six weeks: for the diagnosis--the first three weeks, and for the prevention and treatment--all six weeks.

De Barsy syndrome and ATP6V0A2-CDG

We read with interest the nice review of Morava et al1 on the autosomal recessive cutis laxa syndromes. The authors mention the De Barsy syndrome and state that the genetic background of the De Barsy syndrome has not yet been identified. However, in the paper by Kornak et al2 on impaired glycosylation and cutis laxa caused by mutations in ATP6V0A2 (ATP6V0A2-CDG according to the novel nomenclature3, 4), one of the patients (see patient CoFe in Table 1 of Kornak et al2) shows the full clinical picture of the De Barsy syndrome, including cutis laxa, facial dysmorphy, dwarfism, psychomotor retardation, dystonia, congenital hip dysplasia, and corneal dystrophy necessitating repeated corneal transplantation. These data suggest that a subgroup of patients with De Barsy syndrome5 belongs to the spectrum of ATP6V0A2-CDG. Another cause of De Barsy syndrome has very recently been identified as mutations in PYCR1, coding for a mitochondrial enzyme involved in proline metabolism.6 Therefore, we recommend a systematic screen for ATP6V0A2-CDG and for mutations in PYCR1 in patients with De Barsy syndrome.

Reply to Leao-Teles et al

We appreciate the comments1 on our review on autosomal recessive cutis laxa syndromes,2 especially the novel information on the Portuguese patient CoFe3 (Table 1, Kornak et al), who was diagnosed with a combined N- and O-linked glycosylation disorder and ATP6V0A2-CDG. De Barsy syndrome is a challenging diagnosis, and has overlapping features with ARCL type 2, including cutis laxa, short stature, late closure of the fontanel, congenital hip dysplasia, some aspects of facial dysmorphism and psychomotor retardation.4 Still, dystonic movements and progressive corneal abnormalities are highly suggestive of De Barsy syndrome. So far no cobble-stone-like brain dysgenesis has been observed in De Barsy syndrome patients. Although the clinical differentiation is not always straightforward, progeroid features, the presence of pergamen-like skin and the absence of subcutaneous fat are distinctive.2 Interestingly, some of the patients, recently reported to have PYCR1 mutations, were previously diagnosed with De Barsy syndrome,5 while other De Barsy patients were found to not harbour PYCR1 mutations (unreported data), thus supporting genetic heterogeneity. We would appreciate further description and photo documentation of this unique patient, reported by Leao-Teles, as in our own cohort of six patients with De Barsy syndrome and those studied by Kornak et al (personal communication) none of the children had either N-linked or O-linked glycosylation abnormalities, nor mutations in the ATP6V0A2 gene. Eye anomalies are common in N-glycosylation disorders,6 and strabismus and high myopia have been reported in combined glycosylation disorders.4 The exceptional observation of corneal abnormalities with a movement disorder in association with ATP6V0A2-CDG indeed widens the range of symptoms evoking glycosylation studies in patients with cutis laxa.

Developmental dysplasia of the hip: Is acetabular retroversion a crucial factor?

The objective of this study was to investigate a possible relation between congenital hip dysplasia and acetabular retroversion and to explore the eventual influence of the latter in the surgical decision for periacetabular osteotomy. We assessed the classical morphological characteristics of both hips, with an additional newly described retroversion index. The study was conducted in 174 patients with uni- or bilateral congenital hip dysplasia having undergone unilateral (153 patients) or bilateral (21 patients) periacetabular osteotomy when respectively one or both dysplastic hips remained symptomatic. In the group of operated hips (195 hips in total), 53% of the acetabuli were anteverted, 42% retroverted, and 5% neutral orientations. The group of nonoperated hips (153 hips) included 24% normal hips, 22% hips with normal coverage but retroverted, 35% dysplastic hips with anteverted or neutral orientation, and 19% dysplastic retroverted hips. Comparing the two hips in the subgroup of patients in whom the operated and nonoperated sides were both dysplastic failed to demonstrate statistically significant difference in the mean retroversion index. However, all the other variables measured were significantly different; with the operated side more dysplastic. Comparing the two hips in the other subgroups showed that acetabular retroversion was nearly always bilateral and symmetrical, even in presence of unilateral congenital dysplasia. Our data suggest that the presence of acetabular retroversion is probably independent of the congenital hip dysplasia and that this abnormality seems at best a secondary factor in the appearance of dysplastic hip symptoms. Level IV, retrospective diagnostic study.

Treatment of Congenital Hip Dysplasia in Early Childhood Using Periacetabular and Combined Wire Tunneling Technique

The influence of periacetabular and combined wire tunneling upon hip bones development in congenital hip dysplasia in 34 children, aged 8-36 months, was studied. Evaluation of the treatment results by dynamics of roentgenologic parameters showed that periacetabular and combined wire tunneling possessed a trophostimulating effect. Differentiated application of these techniques enables to avoid radical reconstructive operations on the ilium and femur in the early childhood or to delay their performance.

Comment on: Clinical examination versus ultrasonography in detecting developmental dysplasia of the hip

Dear Editor, We read the article by Dogruel et al. [2], on the clinical examination versus ultrasonography in detecting developmental dysplasia of the hip, with interest. The purpose of this prospective study was to investigate the usefulness of clinical examination in detecting developmental dysplasia of the hip in infants, as defined by hip ultrasonography. This article is important because developmental dysplasia of the hip is a common, treatable disease, in which the most accurate screening procedure is still debatable. The authors concluded that clinical examination did not reliably detect developmental dysplasia of the hip. Ultrasonography is frequently used as a screening tool in clinical practice, but this method can result in false positive results [3]. The American Academy of Pediatrics (AAP) guideline [1] recommends routine screening for developmental dysplasia of the hip through clinical examination by skilled personnel. In doubtful cases referral to an orthopaedic surgeon is useful. In infants with risk factors, irrespective of the results of clinical examination, ultrasonography should be considered. Although ultrasonography is not the gold standard for the diagnosis of developmental dysplasia of the hip, we understand that it was used in this study to compare the results of ultrasonography with clinical examination. However, when we recalculated sensitivity and specificity in the study by Dogruel et al., we found different values (see Table 1). Table 1 Clinical examination versus ultrasonography in terms of numbers of hips defined as normal or pathological (results Dogruel et al. [2]) The sensitivity is 59/208 = 28%, which is the proportion of hips in which a pathological clinical examination was found in infants with pathological ultrasonography (true-positives). The specificity is 6502/6874 = 95%, which is the proportion of hips in which a normal clinical examination and normal ultrasonography were found (true-negatives). The reported 13.68% (59/431), in the article by Dogruel et al. cited as the specificity, is in fact, the predictive value of a positive test, i.e. the percentage of infants with ultrasonography defined dysplasia of the hip with a positive clinical examination. The percentage reported by the authors as sensitivity is, in fact, the prevalence of non-disease (6874/7082 = 97%). These different values may influence the conclusions reached by the study. From the results of the study described by Dogruel et al., we concluded that the sensitivity of clinical examination of the hip in diagnosing congenital hip dysplasia was very low. The question is whether this is due to the index test (the sensitivity of clinical examination is too low) or because of the reference test (ultrasonography used as the gold standard, but known to show false positive results). The specificity of clinical examination (95%) seems quite high. However, this study was performed on healthy infants, with a low a priori chance of 2.9% (208/7082). This percentage however is consistent with other study results. Because of the high negative predictive value (6502/6651 = 97.8%) we conclude that screening by physical examination is useful.

Modifizierte Azetabuloplastik unter Verwendung von bioresorbierbaren Schrauben und lyophilisiertem allogenem Knochen

Various pericapsular procedures are available to surgically improve the acetabular coverage of the femoral head prior to closure of the triradiate cartilage. In this study the acetabuloplasty with the modification according to Westin (Pember-Sal) was applied. Indications for surgery were congenital hip dysplasia or luxation as well as Perthes' disease. To date, the standard procedures for acetabuloplasty include the transplantation of an autologous iliac crest bone graft and the fixation with K-wires. The aim of this study was to investigate if a modification of the operative procedure with the use of resorbable screws and allogenic bone transplants can minimise the operative trauma, avoid a second procedure, and permit MRI follow-ups without increasing the risk of the operation. 15 patients with a mean age of 6.7 years were included in this case series and treated with a modified acetabuloplasty for the indication hip dysplasia or Perthes' disease. The modification of the standard procedure included the transplantation of allogenic bone wedges customised from lyophilised femoral grafts. The fixation was performed with bioresorbable polylactide screws. Clinical and radiographical follow-ups were conducted. Procedure-related complications occurred neither in the intra- nor the postoperative period. The allogenic bone graft was remodelled successively as seen on radiographic controls. Dislocations of the bone wedges were not detectable. Subsiding of the allograft did not occur to a noticeable extent as the acetabular index showed no increase during follow-up. This study presents a gentle method of acetabuloplasty which avoids iliac crest bone harvesting with its known complications as well as a second procedure under anaesthesia for the removal of implants.

Pregnancy Outcomes in Women Exposed to Adalimumab

Purpose: The fully human, anti-tumor necrosis factor monoclonal antibody adalimumab is approved for the treatment of rheumatoid arthritis (RA), psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and psoriasis in the United States, Europe, and elsewhere, as well as for juvenile idiopathic arthritis in the United States. Methods: This report describes preliminary outcomes from an ongoing study of the safety of adalimumab in RA patients during pregnancy conducted by the Organization of Teratology Information Specialists (OTIS). Through a prospective cohort design, women with RA treated with adalimumab during the first trimester of pregnancy were followed for 1-year postpartum. Pregnancy outcomes were compared with those from a disease-matched group of pregnant women with RA who had not been treated with adalimumab during their pregnancies, and a non-diseased group of women who neither had RA nor had been treated with adalimumab. In addition to conducting the cohort study, the OTIS investigators also collected information on adalimumab-exposed pregnancies that did not meet the cohort criteria, but were followed as a case series. The case-series pregnancies are presented separately as they have no comparison group. They include patients treated for diseases other than RA, as well as retrospectively reported outcomes. Results: As of May 15, 2008 (4 years of the study), pregnancy outcomes were available for 126 women in the cohort (Table). Two major structural defects (6.6%) had been reported for 30 women with adalimumab exposure during their first trimesters for whom pregnancy outcomes were known: 1 with undescended testicle and 1 with microcephaly. For 51 pregnancies in the disease-matched comparison group for which pregnancy outcomes were known, 1 fetus (2.0%) was diagnosed with chromosomal abnormalities. Two major structural defects (5.1%) have been reported via 39 pregnancies with known outcomes in the healthy comparison group. In the case-series group (data not included in the Table), of the 66 known outcomes, 7 (10.6%) resulted in major congenital defects — 3 chromosomal anomalies, 1 spina bifida with hydrocephalus, 1 ventricular septal defect, 1 congenital hip dysplasia with inguinal hernia, and 1 congenital hypothyroidism. Of these 66 known outcomes in the case series, 23 had a diagnosis of Crohn's disease.Table: Pregnancy Outcomes in the OTIS Cohort StudyConclusion: Based on these preliminary data, no concerns have been raised regarding increased risks for adverse pregnancy outcomes associated with early pregnancy exposure to adalimumab in the treatment of RA. Firm conclusions await accumulation of sufficient sample size in this prospective cohort study. In Fall 2008, the OTIS cohort study will expand enrollment to include patients with Crohn's disease.

Quality of life evaluation in patients affected by osteoarthritis secondary to congenital hip dysplasia after total hip replacement

BackgroundThe aim of the study was to evaluate the quality of life (QoL) in patients affected by osteoarthritis (OA) secondary to congenital hip dysplasia (CHD) and treated by hip arthroplasty.MethodsWe prospectively treated 40 patients admitted to our hospital between 2001 and 2006. Each patient was asked to answer to two questionnaires: WOMAC and MOS SF-36. Patients were evaluated four months before surgery and once they had achieved postoperative rehabilitation. Pre- and postoperative results were analyzed and compared with the international literature on patients affected by OA and also with a healthy population. ResultsPre- and post-operative results: WOMAC: pain 14.06–0.84; stiffness 4.26–0.52; function 42.68–5.39. SF-36: physical function 18.55–84.52; role physical 28.33–87.10; body pain 23.26–83.39; general health 55.19–81.74; vitality 32.74–72.10; social function 43.55–84.66; role emotional 68.82–93.55; mental health 48.77–79.35. All results were statistically significant.ConclusionsThe study reports an important QoL improvement in patients affected by arthritis secondary to CHD that underwent hip surgery, and underlines differences with respect to primary OA. QoL evaluation cannot replace either clinical and instrumental evaluation or the physician’s experience, but it can give weight to the patient’s expectations, and may be considered an efficient test for medical and surgical treatments.

Röntgenologische Untersuchung der Säuglings- und Kleinkinderhüfte

In the age of sonography, there is increasing disapproval of radiologic examination of the hip in infancy and early childhood. Justifiably, the sonogram has replaced the X-ray in many examinations of the hip joint in infants and small children, thus sparing them radiation exposure. It must be remembered, however, that sonography is primarily a screening method for detecting congenital hip dislocation and dysplasia in infancy. There is still no substitute for radiologic examination of hip joints which require treatment or have been treated. Performance of survey radiograms, and if necessary arthrography, with a specific diagnostic goal permits an interpretation of all pathomorphologic changes associated with hip dislocation in infancy and early childhood. There is no place for computerized tomography in this context. It is still impossible to predict the extent to which, in the future, magnetic resonance imaging, with new coil configurations and shorter examination times, will open a new chapter in hip joint examination.

Früherfahrungen mit der Mini-Hüftgelenkstotalendoprothese (Modell “St. Georg-Mini”) bei Dysplasie-Coxarthrose

The results of 106 patients with osteoarthritis secondary to severe congenital hip dysplasia and dislocations of the hip operated at the Endo-Klinik were evaluated after an average follow up of 21 months. 142 "St. Georg-Mini" total hips were implanted employing Refobacin-Palacos R. The clinical results were graded as "combined performance" which considered hip pain, walking distance, hip mobility and walking aids. In 93% of the cases "combined performance" was improved at follow up and 91.7% of the patients were satisfied with the result. The early (during hospitalization) and late (after discharge from hospital) complication rate which had an influence on the result at follow up was 2.1% (n = 3) and 3.5% (n = 4) respectively. There were no deep infections. An extended indication for total hip arthroplasty also for younger patients with severe osteoarthritis secondary to hip dysplasia is discussed and can be advocated.

Reliabilität der digitalen Messung des AC-Winkels bei der Hüftreifungsstörung an Röntgenaufnahmen zum Gehbeginn

An assessment of the reproducibility of the acetabular index on the basis of anteroposterior radiographs of the pelvis was performed in order to rule out residual dysplasia of the hip in the second year of life. 51 consecutive patients (41 girls, 10 boys) with congenital dysplasia of the hip (35 bilateral, 16 unilateral) were included. Approximately at the time children started walking (mean age: 13.9 months; range: 10 - 22 months), digitised anteroposterior radiographs of the pelvis were recorded. Acetabular indices were measured bilaterally and blinded by two observers (O1 and O2), then classified according to the normal values of the hip joint described by Tönnis et al. (normal = lower single standard deviation [s], light dysplasia = above single standard deviation [s - 2 s] and severe dysplasie = above double standard deviation [2 s]). O2 repeated a second set of observations 6 weeks after the first. 306 values of the acetabular index (O1: 102 values; O2: 204 values) were statistically evaluated. Reliability was expressed by Pearson's correlation coefficient (PCC) and 95 % confidence interval. The rater agreement of the classification into normal values of the hip joint was calculated with the kappa coefficient. The PCC for intraobserver/interobserver reliability was 0.928/0.875. The 95 % confidence interval for intraobserver reliability was +/- 3.1 degrees and for interobserver reliability - 3.1 degrees /+ 5.9 degrees . A comparison of the first series of measurements by O1 with the series of measurements by O2 presented congruence in 66 of 102 hip joints classified according to the normal values of the hip joint as described by Tönnis. In 36 hip joints the classification was deviant, in 15 the classification differed between normal and s, in 21 between s and 2 s. The kappa coefficient of 0.51 showed moderate interobserver agreement. The reproducibility of radiological surveillance in congenital hip dysplasia, approximately to the time children start walking, can be considered as adequate. Correct positioning of the patient and exact definition of radiological landmarks are essential. In spite of good statistical values for reliability, decreasing accuracy in classifying into Tönnis' normal values of the hip joint is seen with increasing degree of dysplasia. In marginal cases, before coming to the decision for operative treatment, a second reading, ideally by the same observer and with a chronological shift, is advisable.

Diagnose und Therapie der Hüftdysplasie des älteren Kindes

Diagnosis of congenital hip dysplasia is based on normal values of the acetabulum, but also criteria such as deficiency of the acetabular rim and an increased distance from the tear drop figure. Instability of the hip joint is seen in arthography. Acetabuloplasty is the way to treat it. Unstable joints will deteriorate, stable ones are frequently improving spontaneously. The technique of open reduction from an inguinal approach medial of the psoas muscle is described. There are many advantages. Simultaneous shortening osteotomy and acetabuloplasty to permit immediate movements out of the hip spica are recommended to avoid stiffening and contractures. Hip dysplasia is corrected by a lateral acetabuloplasty that levers down the acetabular roof in the triradiate cartilage. After consolidation of the cartilage triple pelvic osteotomy for acetabular rotation is the method to correct dysplasia in adolescents and adults. The closer the osteotomies are performed to the hip joint, the better rotation is possible. Our technique has proved successful now in 12 years.

Über das Auftreten der Hüftkopfkernepiphyse bei gesunden Kindern und Kindern mit Hüftdysplasie

In a retrospective study we evaluated 4341 sonographic examinations of 1160 healthy children and 209 children with congenital hip dysplasia with special reference to the appearance of the femoral head epiphysis. In healthy children the epiphysis appeared between the first and seventh month. In more than 95% of the children, the epiphysis was sonographically present after the seventh month. In children with congenital hip dysplasia the first appearance of the femoral hip epiphysis had a retardation of one to two months. In most of the healthy children the epiphysis appeared in the fourth month, and after the ninth month in almost all of the normal hip joints the epiphysis is present. In children with normal hip joint configuration and missing femoral head epiphysis at three months, the final ultrasound examination should not be done before the seventh month. Thus, clinically unnecessary ultrasound examination in 6-week intervals can be reduced.

Experiences with a 3-D ultrasound system in infant hip joints

To test the possibilities of 3-dimensional sonography in diagnosing congenital hip dysplasia. 128 infant hip joints were examined by 4 investigators with different levels of experience. The Kretz Combison 530 machine additionally equipped with an automatic 5 MgHz transducer and volume box system was employed. The average time to determine the standard plane was 21 seconds. The single standard deviation for alpha values in the 3-dimensional system was 3.0 degrees, compared to 1.37 degrees in the conventional system. Observer experience was not a crucial factor. The described 3-dimensional system makes it quicker and simpler to determine the standard plane when evaluating infant hips. The higher standard deviation is possibly caused by the obliquity of the ultrasonic beam. Ossification defects on the acetabular roof are better visualized with this approach than with conventional ultrasound or radiological methods. Even though 3-dimensional ultrasound represents a new approach to infant hips, it seems worthy of rapid development.

Diagnosis of congenital hip dysplasia in the newborn

Background and purpose Screening of newborn infants for congenital hip dysplasia may be done by clinical examination, ultrasound, or radiography—or a combination of these. Studies that have used clinical examination followed by ultrasound imaging for infants with certain risk factors have shown excellent results, but they were performed by very experienced practitioners. We wanted to find out whether the results of such screening would be equally good with less optimal staffing. Thus, we evaluated the real‐life performance of a screening program for detection of congenital hip dysplasia in newborn infants.Subjects and methods We performed a retrospective chart review of all infants (n = 1,983) referred for evaluation for suspected congenital hip dysplasia from one single obstetric hospital, where 19,820 infants had been screened from 1992 through 2001. Infants were referred either because of a positive finding during the Ortolani and Barlow examinations or because of the presence of risk factors.Results The reasons for referral of the 1,983 infants (10% of those examined) were: positive clinical signs in 255 (1.3% of all examined) and risk factors in 1,547 (7.8%), and a combination of both in 114 (0.6%). 67 other infants (0.3%) who had passed the initial pediatric screening were later referred from the local health centers. Finally, 23 of the 1,983 infants were subsequently referred again by their health center for renewed orthopedic evaluation. Of the infants who were treated (298/1,983 = 15% of those referred), those with a pathological examination result were represented proportionately more than infants who were referred because of risk factors (0.8% as opposed to 0.5%). Delayed diagnoses occurred in 1.7/1,000 infantsInterpretation The performance of a screening protocol for congenital hip dysplasia in a real‐life setting involving several physicians both on the pediatric and orthopedic side may not live up to expectations based on the use of such a protocol in an optimized setting. This type of analysis of screening data may serve to pinpoint weaknesses, and thus lead to adjustments that may enhance quality.

The Custom Femoral Component is an Effective Option for Congenital Hip Dysplasia

Although custom-designed femoral prostheses seem more likely to be successful than off-the-shelf components for treatment of patients with osteoarthritis secondary to congenital hip dysplasia, published short-term results of custom stems with a smooth surface or titanium proximal mesh pads are no better than results for off-the-shelf components. To determine whether cementless custom femoral components with sandblasted surfaces provide better results than other custom stems, we prospectively evaluated 77 consecutive patients (99 hips) with a mean age of 54 years who had osteo-arthritis secondary to congenital hip dysplasia. The mean followup was 9 years 3 months. Forty-seven hips were classified as having Crowe Type I deformity, 41 were classified as having Crowe Type II deformity, and 11 were classified as having Crowe Type III deformity. The average Harris hip score was 97.6 points at the last followup. Radiographically, 88 hips (89%) showed bone ongrowth, seven hips (7%) showed stable fibrous fixation, and four hips (4%) showed unstable fixation. There were two intraoperative femoral fractures and varus malpositioning of four stems in the hips with stable fibrous fixation and the unstable hips. One femoral component was revised 6 years postoperatively. Although the anatomic cementless custom-designed femoral components with sandblasted surfaces provided favorable results in patients with Crowe Types I, II, and III deformities, intra-operative technical errors prevented bone ongrowth fixation.

Evaluation of ilial screw loosening after triple pelvic osteotomy in dogs: 227 cases (1991–1999)

To investigate factors influencing screw loosening after triple pelvic osteotomy (TPO) and ischial wire stabilization of the acetabular segment. Retrospective case series. Animals-227 dogs with congenital hip dysplasia or subluxated hip joints. Medical records and radiographs of 227 dogs that underwent 332 TPO procedures were evaluated, and data pertaining to screw type, plate position, sacral screw engagement, use of ischial interfragmentary wires, and pelvic alignment were assessed for associations with screw loosening. Complications developed in 96 of the 332 (29%) procedures. Cancellous screws without sacral engagement were associated with the lowest frequency (6%) of loosening, compared with cancellous and cortical screws engaging the sacrum and cortical screws that did not engage the sacrum. Frequency of screw loosening increased when cortical or cancellous screws engaged the sacrum and when cortical screws were used. In dogs that had surgery bilaterally, the first limb on which TPO was performed had a higher frequency of screw loosening than the second limb. Pelvic alignment loss was greatest (5.4 degrees ) when the 3 most cranial screws were loosened. Loss of pelvic alignment was significantly different between dogs that underwent surgery and had complications and those that underwent surgery and did not have complications in association with loosening of 1, 2, and 3 screws. TPO screw loosening was multifactorial and related to stability of the affected ilium, screw type, and screw position. Placing cancellous screws that do not engage the sacrum in pelvic osteotomy plate positions 1 through 3 may decrease the number of screws that loosen.

HO prevention and the combined therapeutic protocol—do we really need it?

We would like to comment on the article by E.E. Pakos et al. entitled Prevention of heterotopic ossification in high-risk patients with total hip arthroplasty: the experience of a combined therapeutic protocol [5]. First, we would like to congratulate the authors for their contribution to the relevant literature. In the authors’ study, ankylosing spondylitis, hypertrophic osteoarthritis, diffuse skeletal hyperostosis, biochemical factors, male sex and a previous history of heterotopic ossication are defined as risk factors [5]. They also stated that this kind of study (combined radiotherapy and NSAID) has not been done before. They could not find a difference regarding the types of prosthesis, but found a statistically significant incidence of HO in females and in patients of osteoarthritis secondary to congenital hip dysplasia [5]. Heterotopic ossification (HO) is a common problem, especially after total hip replacement (THR) or after fracture treatment around the hip. With a brief literature review, we found studies taking an opposing view to this study in which additional medication to radiotherapy caused no improvement of the clinical outcome [1]. Combined treatments were used post actebular fractures and were found to be effective [4]. The authors stated that male sex is a risk factor, but have found HO to be increased in females. At the end of their study, they did not provide an explanation for this phenomenon. In many studies, HO was found to be more frequent in male and elderly individuals, as well as in patients with primary osteoarthritis [6]. Also in other studies, a high body mass index, low preoperative range of motion, length of operative time and large osteophytes were defined as high risk factors [3]. This could be the reason why HO is more frequent in females in this study (DDH is more frequent and the operative time is lenghtened in these patients) [5]. The author’s study is extremely valuable, but if they had a control group consisting of patients with isolated radiotherapy or an indomethacin group, then the comparison and distinction would be much easier. In some studies, even a single dose application of indomethacin was found to be effective in high-risk patients [2]. Also, this is the cheapest method of prophylaxis [2]. In conclusion, regarding the prosthetic treatment of hip fractures or osteoarthritis, HO risk factors should be clearly identified to decrease morbidity with low costs of prophylaxis. In our clinic, we use the C-reactive protein levels as a postoperative predictor of HO. We also use indomethacine because of its low cost and effectivity, regardless of the HO risk group, with convenience both for HO prophylaxis and for pain control in the postoperative setting.