Rapid Prototyping 3D Model in Treatment of Pediatric Hip Dysplasia: A Case Report

BACKGROUND

Rapid prototyping is an emerging technology that integrates common medical imaging with specialized production mechanisms to create detailed anatomic replicas. 3D-printed models of musculoskeletal anatomy have already proven useful in orthopedics and their applications continue to expand.

CASE DESCRIPTION

We present the case of a 10 year-old female with Down syndrome and left acetabular dysplasia and chronic hip instability who underwent periacetabular osteotomy. A rapid prototyping 3D model was created to better understand the anatomy, counsel the family about the problem and the surgical procedure, as well as guide surgical technique. The intricate detail and size match of the model with the patient's anatomy offered unparalleled, hands-on experience with the patient's anatomy pre-operatively and improved surgical precision.

CONCLUSIONS

Our experience with rapid prototyping confirmed its ability to enhance orthopedic care by improving the surgeon's ability to understand complex anatomy. Additionally, we report a new application utilizing intraoperative fluoroscopic comparison of the model and patient to ensure surgical precision and minimize the risk of complications. This technique could be used in other challenging cases. The increasing availability of rapid prototyping welcomes further use in all areas of orthopedics.

Alumina Delta-on-Highly Crosslinked-Remelted Polyethylene Bearing in Cementless Total Hip Arthroplasty in Patients Younger than 50 Years

BACKGROUND

The purpose of this retrospective study was to determine the clinical and radiographic results, prevalence of polyethylene wear and osteolysis, and fracture of alumina delta ceramic femoral head or highly crosslinked, remelted polyethylene (HXLPE) liner associated with the use of alumina delta ceramic femoral head-on-HXLPE bearing in cementless total hip arthroplasty in patients younger than 50 years.

METHODS

We reviewed the cases of 119 patients (130 hips) who underwent a cementless total hip arthroplasty using alumina delta ceramic-on-HXLPE bearing when they were 50 years or younger at the time of surgery. The most common diagnoses were osteonecrosis (51%) and osteoarthritis secondary to developmental dysplastic hip (39%). Osteolysis and polyethylene wear rates were evaluated with use of radiography and computed tomography. In addition, prevalence of fracture of alumina delta ceramic head and polyethylene line was documented. The mean follow-up was 8.3 years (range, 7-9 years).

RESULTS

The mean Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index score, University of California, Los Angeles activity score were 94 points, 14 points, and 8.1 points, respectively, at the final follow-up. No patient had thigh pain. All acetabular components and all but one femoral components were well fixed. The mean annual penetration rate of femoral head was 0.022 ± 0.003 mm/year. No hip had osteolysis or ceramic head or HXLPE liner fracture.

CONCLUSION

Our average 8.3-year results with the use of alumina delta ceramic-on-HXLPE bearing in the patients younger than 50 years suggest that cementless acetabular and femoral components provide a high survival rate without evidence of osteolysis or ceramic head or AXLPE liner fracture.

Reducing the failure rate of hip resurfacing in dysplasia patients: a retrospective analysis of 363 cases

BACKGROUND

Arthritis secondary to developmental hip dysplasia often mandates implant surgery at a relatively young age. Hip resurfacing arthroplasty (HRA), compared with standard stemmed total hip arthroplasty (THA), affords a more active lifestyle including extreme-motion activities but stimulates concerns pertaining to implant failure.

METHODS

We addressed the primary modes of failure through a series of interventions, including a new guideline for achieving proper implant alignment through intraoperative x-rays. We then compared two sequential cohorts in a single-surgeon practice: patients with developmental dysplasia who underwent HRA before (Group 1; 121 hips in 105 patients) and after (Group 2; 242 hips in 210 patients) June 2008, at which time the four interventions were all in place.

RESULTS

Implants in Group 2 failed less frequently within two years (0.8 % vs. 6.6 %, p = 0.002) and were more likely to have projected seven-year Kaplan-Meier survivorship (99 % vs. 89 %, p < 0.0001 by log-rank test). Patients in Group 2 were more likely to have normal metal ion levels (77 % vs. 56 %, p = 0.0008) and optimum metal ion levels (99 % vs. 86 %, p = 0.0008). Patients in Group 2 also benefited from a 19-min decrease in mean operation time, a 45 % decrease in mean estimated blood loss, and a 0.9-day decrease in mean hospital stay (p < 0.0001 in each instance).

CONCLUSIONS

We believe the interventions reported here, combined with sufficient surgeon experience and properly designed implants, afford patients with mild developmental dysplasia a more active lifestyle with favorable implant survival.

How Often Does Femoroacetabular Impingement Occur After an Innominate Osteotomy for Acetabular Dysplasia?

BACKGROUND

Femoroacetabular impingement is increasingly recognized as a cause of hip pain but its incidence after an innominate osteotomy for the correction of acetabular dysplasia has not been determined. This information would be essential for the orthopaedic surgeon because it has the potential to produce a poor outcome in the long term when trying to balance acetabular instability and overcorrection.

QUESTIONS/PURPOSES

The purposes of our study were (1) to determine the frequency with which clinically relevant femoroacetabular impingement (FAI) occurs after an innominate osteotomy for the treatment of acetabular dysplasia; (2) to determine risk factors for the development of FAI; and (3) to compare postoperative radiographic and clinical outcomes in patients having undergone an innominate osteotomy for the correction of acetabular dysplasia both with and without FAI.

METHODS

This was a retrospective review of 154 hips (132 patients) that had undergone an innominate osteotomy for acetabular dysplasia and were evaluated at a minimum followup of 10 years (mean = 12 years). Mean age at the time of surgery was 3 years, 114 hips had a concomitant open reduction, and 54 hips also had femoral shortening. One hundred eight hips had a Salter osteotomy and 46 had a Pemberton osteotomy. Radiographs were analyzed to determine the lateral center-edge angle (CE angle) and the presence of a crossover sign. The diagnosis of FAI was established when the CE angle was greater than 40°, there was a positive crossover sign, and the patient had groin pain when flexing the hip less than 90°. Comparisons between nonparametric variables were performed with a Mann-Whitney's U test. Categorical variables were compared with a chi-square test. Change in acetabular index (correction) was dichotomized considering 20° of correction as the cutoff point. Association is presented as odds ratio (95% confidence interval), and logistic regression was performed.

RESULTS

According to our criteria, 18 of 154 hips had FAI (12%). Of the 18 patients with FAI, 10 had undergone a Pemberton osteotomy (10 of 46 [22%]) and eight a Salter osteotomy (eight of 108 [7%]). A change in the postoperative acetabular index greater than 20° was associated with a greater likelihood of developing FAI. The mean postoperative acetabular index was lower for the group with FAI, for whom it was 20°, compared with the group without FAI, for whom it was 27° (p = 0.04). The mean Iowa Hip Score for the group with FAI was 85, whereas for those without FAI, it was 93 (p = 0.03).

CONCLUSIONS

FAI is not common after an innominate osteotomy for the treatment of acetabular dysplasia; however, overcorrection is related to a higher incidence. When FAI is present, it can affect the outcome. Overcorrection should be avoided when performing an innominate osteotomy for the treatment of acetabular dysplasia because it can create iatrogenic FAI and have an adverse effect on outcome.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Curtain osteophytes are one of the risk factors for the poor outcome of rotational acetabular osteotomy

PURPOSE

Rotational acetabular osteotomy (RAO) is one of the surgical procedures for painful dysplastic hips. Although several risk factors for poor outcome of RAO have been reported, the presence of a curtain osteophyte in the acetabulum has not been evaluated as a possible risk factor. This study aimed to analyze the risk factors affecting the outcome of RAO and to clarify whether curtain osteophytes are one of the risk factors.

METHODS

We retrospectively analyzed 87 hips in 78 patients with a mean age of 36 (range, 13-54) years. The mean follow-up period was 8.3 (range, 2.1-19.5) years. The radiographic severity of osteoarthritis was classified into four stages: pre-arthrosis, initial stage, advanced stage, and terminal stage. The Japanese Orthopaedic Association (JOA) hip score was used for clinical evaluation. Poor outcome was defined as a hip with a JOA score < 80 points or terminal-stage osteoarthritis at final follow-up. Several factors were evaluated by logistic regression analysis.

RESULTS

At final follow-up, ten hips had a JOA score < 80 and nine hips had progressed to terminal-stage osteoarthritis. Since five hips had a JOA score < 80 as well as terminal-stage osteoarthritis, a total of 14 hips were determined to have poor outcome. An additional ten years of age at surgery, pre-operative minimal joint space < 2 mm, presence of a curtain osteophyte, and fair/poor congruency in abduction were identified as significant risk factors for poor outcome of RAO.

CONCLUSIONS

Hips with curtain osteophyte should be evaluated carefully before RAO.

Developmental Dysplasia of Spastic Hip in Children with Cerebral Palsy in Southern India

We studied the proportion of developmental dysplasia of spastic hip in children with cerebral palsy. Children with cerebral palsy aged 2-12 years were enrolled. Migration percentage was measured on pelvic radiographs. Hip dysplasia was seen in 15 (12.7%) children.

[Surgical treatment for osteoarthritis secondary to Crowe type IV developmental dysplasia of hip in adults]

OBJECTIVE

To investigate the mothod and therapeutic efficacy of total hip anthroplasties (THA) for osteoarthritis secondary to Crowe type IV developmental dysplasia of hip in adults.

METHODS

From May 2006 to December 2013, THA was performed on 15 adult patients (17 hips) with Growe type IV acetabular dysplasia, including 13 females and 2 males, with a mean age of 30.9 years old (22 to 58 years old) and an average preoperative Harris score of (34.0 ± 6.5) points. Traction of the affected limb was not performed before surgery. After extensive release and lengthening of soft tissues, sub-trochanteric osteotomy of the femur was performed, hip joint center was rebuilt and the abduction function was restored.

RESULTS

The patients were followed up with a mean period of 33 months (ranged from 6 months to 5 years). The postoperative Harris score was 85.0 ± 7.3,higher than the preoperative score. The extended length of limb ranged from 1.6 to 5.4 cm, with a mean of (3.42 ± 0.65) cm. The shortening and malformation of the affected limb were corrected in the most patients,with the difference in length of the two legs less than 1.5 cm. After surgery, 1 patient experienced partial sciatic nerve injury, which was largely recovered after 3 months of conservative treatment. One patient experienced complete sciatic nerve injury, which was partially recovered after 6 months of conservative treatment; a foot-drop varus deformity was formed in the distal end of the affected limb, which was improved after tendon transposition and transplantation. Joint pain was relieved, and the joint function was restored significantly. Over the follow-up period, no severe complications such as dislocation, infection, prosthesis loosening, or subsiding occurred.

CONCLUSION

Satisfactory efficacy can be achieved for adult Growe type IV acetabular dysplasia associated with osteoarthritis by THA, with proper soft tissue release and lengthening, sub-trochanteric osteotomy of femur, joint functional restoration, appropriate choice of prosthesis, and careful protection of nerves and vessels.

Common questions about developmental dysplasia of the hip

Developmental dysplasia of the hip is a common musculoskeletal condition in newborns. Infants with developmental dysplasia of the hip, whether treated or untreated, have a higher incidence of early-onset hip osteoarthritis in adulthood. Evidence to support universal screening by physical examination or ultrasonography is limited and often conflicting. The U.S. Preventive Services Task Force found insufficient evidence that screening for developmental dysplasia of the hip prevents adverse outcomes. Physical examination screening is recommended by the American Academy of Pediatrics and the Pediatric Orthopaedic Society of North America. These organizations recommend use of the Ortolani and Barlow maneuvers to screen infants up to three months of age. Several recent studies support starting assessment for limited hip abduction at eight weeks of age, which is the most sensitive test for developmental dysplasia of the hip from this age on. Infants with overtly dislocated or dislocatable hips should be referred to an orthopedist on a priority basis at the time of diagnosis. Infants with equivocal hip examination findings at birth can be reexamined in two weeks. If there is subluxation or dislocation at the follow-up examination, referral should be made at that time. If the examination findings are still equivocal, the infant can undergo ultrasonography of the hips or be reexamined every few weeks through the first six weeks of life. Although equivocal findings commonly resolve spontaneously, infants with persistent equivocal findings of developmental dysplasia of the hip longer than six weeks should be evaluated by an orthopedist. Treatment generally involves flexion-abduction splinting. The benefits of treatment are unclear, and there are risks to treatment, most notably an increased occurrence of avascular necrosis of the femoral head.

Total hip arthroplasty for Crowe IV hip without subtrochanteric shortening osteotomy -a long term follow up study

BACKGROUND

Several authors reported encouraging results of total hip arthroplasty (THA) for Crowe IV hips performed using shortening osteotomy. However, few papers have documanted the results of THA for Crowe IV hips without shortening osteotomy. The aim of the present study was to assess the long term-results of cemented THAs for Crowe group IV hips performed without subtrochanteric shortening osteotomy.

METHODS

We have assessed the long term results of 27 cemented total hip arthroplasty (THA) performed without subtrochanteric osteotomy for Crowe group IV hip. All THAs were performed via transtrochanteric approach.

RESULTS

After a mean follow-up of 10.6 (6 to 17.9) years, 25 hips (92.6%) had survived without revision surgery and survivorship analysis gave a survival rate of 96.3% at 10 years with any revision surgery as the end point. Although mean limb lengthening was 3.2 (1.0 to 5.1) cm, no hips developed nerve palsy. Complications occurred in four hips, necessitating revision surgery in two. Among the four complications, three involved the greater trochanter, two of which occurred in cases where braided cables had been used to reattach the greater trochanter.

CONCLUSIONS

Although we encountered four complications, including three trochanteric problems, our findings suggest that THA without subtrochanteric shortening osteotomy can provide satisfactory long-term results in patients with Crowe IV hip.

Developmental dysplasia of the hip: diagnosis and management to 18 months

Developmental dysplasia of the hip represents a spectrum of disease ranging from transient neonatal instability to established dislocation. It is accepted that female sex, breech presentation, and family history are risk factors for the disease. Early diagnosis by clinical examination or ultrasound imaging is emphasized, with splint treatment ideally commencing by 6 weeks of age. Treatment using the Pavlik harness is successful in up to 90% of patients. Ultrasound imaging is the gold standard for monitoring a patient during harness wear. Failed splintage or late presentation usually necessitates surgical intervention depending on the patient's age and the severity of the hip dysplasia and displacement.

Surgical treatment of developmental dysplasia of the hip

Ideally, developmental dysplasia of the hip is treated early in childhood by nonsurgical methods. If these methods are ineffective, surgical reduction in a nonambulating child is required. A young child (age 6 to 18 months) who requires surgical reduction can be treated by formal anterior open reduction or by the medial Ludloff approach to the hip. Additional bony procedures are usually not required in these young patients. Delayed diagnosis is still common, requiring surgical reduction for children of walking age. These older children usually require formal open reduction (anterior approach) plus an associated bony osteotomy (acetabular, proximal femoral, or, in some cases, both types of osteotomies) to better stabilize the hip. The addition of a proximal femoral derotational shortening osteotomy for open reduction in older children was first used in children older than 3 years, but now it is commonly used in children as young as 2 years. This osteotomy decreases the forces on the reduced hip and minimizes the chances for redislocation and osteonecrosis. In all surgical procedures for developmental dysplasia of the hip, the surgeon must avoid too great a focus on bony osteotomies because the management of soft-tissue abnormalities is critical in achieving a stable reduction.

[Three-dimensional finite element analysis of acetabular prosthesis in an adult patient with total flip arthroplasty for high dislocation]

OBJECTIVE

To observe stress distributions around the acetabular prosthesis and the bones of a patient who underwent total hip arthroplasty (THA).

METHODS

Finite element analysis (FEA) was performed with an osteoarthritis patient who underwent THA for her secondary hip high dislocations: Scenario A--deepened acetabulum at the true acetabulum with a small 44 mm cup; Scenario B--structural bone graft at lateral acetabular with a 48 mm cup; Scenario C--place tantalum metal acetabular reconstruction at the lateral acetabular with a 48 mm cup; Scenario D--the normal side of the hip. According to the Wasielewski methods, acetabular was divided into four zones, in the same way on the lining surface. Ten points were taken in each zone for measuring the Von Mises stress values.

RESULTS

Scenario A generated significantly greater stress values in the bones in zone one than the other three scenarios. Significantly greater stress was also found in the inner surface of polyethylene over all of the four zones under scenario A compared with those of the scenario B and C, especially in zone one and two. The cup initial micro-mobility for scenario A was 49. 18 microm, 19 times of that of scenario B and 8 times of that of scenario C.

CONCLUSION

(1) Deepened acetabulum with small cup can cause stress concentration in the acetabular bones and liner, leading to large cup initial micro-mobility. (2) Acetabular lateral structural bone grafting and placement of tantalum metal reconstruction have better biomechanical properties, which can enable the use of bigger cups.

[Radiological characteristics of leg length discrepancy and knee varus/valgus deformity among unilateral developmental hip dislocation patients]

OBJECTIVE

To observe the leg length discrepancy and accompanied knee varus/valgus deformity in matured patients with unilateral dislocation of the hip.

METHODS

From March 2011 to December 2012, 28 patients who had unilateral dislocation of hip (Hartofilakidis classification II 17 cases and III 11 cases) were involved in this study.There were 6 male patients and 22 female patients, the age of the patients were 13.4-66.2 years, with mean age of 29.8 years. The standing anteroposterior full leg length X-ray films were obtained. Leg length discrepancy, the length of the femur, the length of the tibia and identified the varus/valgus knee deformities were measured. Statistical analysis was performed. A student's t test for paired samples was done for comparison of the parameters in the same patient between dislocated and undislocated leg, and the χ(2) test were used to assess valgus and varus knees, leg length discrepancy in high dislocation and low dislocation groups.

RESULTS

Seventeen (60.7%) cases had longer femur length on the dislocated side than that on the undislocated side (t = 1.328, P = 0.197), with the maximum lengthening of 32.7 mm and a mean lengthening of 9.5 mm. Twenty-one (75.0%) cases had longer tibia length on the dislocated side (t = 3.039, P = 0.006), with a maximum lengthening of 10.9 mm and a mean lengthening of 4.5 mm. Twenty (71.4%) cases had longer relative leg length on the dislocated side (t = 2.451, P = 0.022), with a maximum lengthening of 25.0 mm and a mean lengthening of 9.4 mm. On the dislocated side of the leg, the degree of valgus angle was 3° ± 4°,while on the undislocated side, that was -3° ± 4°(t = 5.642, P = 0.000). On the dislocated side, 12 cases (42.9%) were of valgus deformities and 1 case was of varus deformity. On the contralateral side, 15 cases of varus deformities (53.6%) and 1 case of valgus deformity were observed(χ(2) = 18.139,P = 0.000).

CONCLUSIONS

Most dislocated legs are longer in length than the contralateral side, both femur and tibia have also lengthened accordingly. Many knees on the dislocated side present valgus deformity, half of the knees on the contralateral side present varus deformity.

Klippel-Trenaunay syndrome in combination with congenital dislocation of the hip

Klippel-Trenaunay syndrome (KTS) is a rare and sporadic disorder characterized by the triad of capillary malformations, venous varicosities, and limb hypertrophy. The clinical manifestations of KTS are heterogeneous. In this report, we present a unique case of KTS in combination with congenital dislocation of the hip (CDH) in a 4-day-old female neonate. The patient had a widespread port-wine stain surrounded by regions of unaffected skin in a mosaic pattern, cutaneous hemangioma on the upper lip, left-sided hemihypertrophy involving the entire body, and also evidence of left CDH (based on the results of a physical examination and radiographic interpretation). We present this case for the rarity of presentation, discuss the relationship between KTS and CDH, and the treatment options available with a brief review of the literature.

Physical activity level improves after periacetabular osteotomy for the treatment of symptomatic hip dysplasia

BACKGROUND

Hip pain secondary to acetabular dysplasia can prevent participation in recreational activities.

QUESTIONS/PURPOSES

We retrospectively evaluated the physical activity level and pain after periacetabular osteotomy (PAO) for the treatment of symptomatic hip dysplasia.

METHODS

Forty-seven female and four male patients with a mean age of 27 years underwent a PAO. Physical activity (UCLA) and pain (WOMAC) were assessed preoperatively, at 1 year, and at minimum 2 years postoperatively. Multivariable linear regression identified substantial, independent factors associated with postoperative activity level.

RESULTS

The UCLA activity scores were on average higher at 1 year and remained higher at minimum 2 years when compared with preoperative scores. Mean postoperative WOMAC pain scores assessed at 1 year and at least 2 years were lower than mean preoperative scores. Age and preoperative physical activity level were strong independent predictors for activity level at 1 year and at minimum 2 years after surgery. Postoperative pain level was a moderate predictor for the level of activity at minimum 2-year followup.

CONCLUSIONS

Physical activity level improves after PAO. Younger age and higher activity levels before surgery and lower level of pain after surgery are predictive factors for postoperative level of activity in the short term. The data presented here may be useful to counsel the active young adult with symptomatic hip dysplasia about the improvement of level of activity to be expected after PAO.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Imaging hip dysplasia in the skeletally mature

Hip disorders in the young adult manifest along a continuum that ranges from an excessively constrained, impinging joint, to an overly shallow, unstable hip. Knowledge of simple measures on plain radiographs can aid in efficient and accurate identification of mechanically compromised hips that may be at risk for premature OA. Improvements in joint-preserving surgery have shown promise in delaying or preventing progression of articular degeneration; thus, timely diagnosis is important. Once a diagnosis is established, specialized imaging can be individualized to supplement surgical planning, assess the degree of cartilage damage, and facilitate discussion regarding the prognosis of hip-preserving procedures.

Short-term outcome among term singleton infants with intrapartum oligohydramnios

AIM

To evaluate rates of early short-term neonatal complications among term singleton newborn infants with oligohydramnios.

METHODS

Retrospective data were collected on 456 term infants with prenatal diagnosis of oligohydramnios and on matched controls, including information on maternal condition and on infant perinatal complications.

RESULTS

Infants in the study group were born with lower birthweight and were SGA compared with those in the control group. Rates of renal malformations were significantly higher in the study group compared with the controls (15-3.3% and 3-0.7%, respectively; p = 0.007). Among the severe oligohydramnios subgroup (Amniotic Fluid Index <2), renal anomalies were even more prevalent compared to other infants with oligohydramnios and to the controls (6-9.8%, 9-2.3% and 3-0.7%, respectively; p < 0.001). The incidence of skeletal deformities (developmental dislocation of hip and torticollis) was higher among the study group.

CONCLUSION

Term infants with oligohydramnios that was detected near birth are associated with a greater prevalence of renal malformations (mostly mild hydronephrosis) as well as congenital torticollis and developmental dislocated hips compared with controls. Postnatal renal evaluation should be considered in infants with severe oligohydramnios.

Patterns of joint damage seen on MRI in early hip osteoarthritis due to structural hip deformities

OBJECTIVE

The aim of this study was to evaluate differences in damage patterns assessed using magnetic resonance imaging (MRI) between hips with femoroacetabular impingement (FAI) and developmental dysplasia of the hip (DDH) as well as to correlate MRI findings with delayed Gadolinium enhanced MRI of cartilage (dGEMRIC) and with patient pain.

DESIGN

This retrospective study included 40 patients (mean age 28.6 ± 11.2 years) who underwent dGEMRIC and morphological MRI of the hip. Twenty-one hips with FAI and 19 with DDH were investigated. A self-developed morphological grading (MRI score) and dGEMRIC evaluation were done on seven radial reformats obtained from an isotropic 3D True-fast imaging with steady state precession (FISP) sequence and an isotropic T1-mapping sequence. The observed damage patterns were summed up into sub-scores and a total MRI score.

RESULTS

Labrum damage, paralabral cysts, and acetabular rim bone cysts were more common in DDH patients than in FAI patients. No significant differences were seen in the occurrence of cartilage damage, bone cysts, or osteophytes. In DDH (but not in FAI), the dGEMRIC index demonstrated a tendency for lower values in areas next to cartilage defects. There was no association between labrum damage and dGEMRIC index. A moderate correlation was seen between Western Ontario and McMaster Universities (WOMAC) pain score and cartilage damage, paralabral cysts, and the total MRI score.

CONCLUSIONS

This study confirms a higher prevalence of labrum damage but not cartilage damage in patients with DDH in comparison to patients with FAI. In addition, our data suggests an association of cartilage damage and paralabral cysts with patient reported pain.

Assessment of adult hip dysplasia and the outcome of surgical treatment

Hip dysplasia and hip joint deformities in general are recognized as possible precursors of osteoarthritic development. Early and correct identification of hip dysplasia is important in order to offer timely joint preserving treatment. In the contemporary literature, several controversies exist, and some of these were the focus of this doctoral thesis. Categorized into subjects, the major findings and their possible importance are listed below. DIAGNOSTIC ASSESSMENT OF HIP DYSPLASIA: A multi-observer study quantified the variability of different methods for diagnostic assessment of hip dysplasia and osteoarthritis and resulted in general recommendations regarding diagnostic assessment of hip dysplasia. Pelvic tilt was shown to differ significantly between the supine and weight-bearing positions in patients with dysplastic hip joints. This is a finding that adds controversy to the application of neutral pelvic positioning during assessment of hip deformities because pelvic tilt affects the appearance of acetabular version. Weight-bearing assessment of acetabular version showed the presence of retroversion in 33% of dysplastic hips. The establishment of retroversion as a rather frequent entity in dysplastic hips is contradictory to the historical finding that hip dysplasia is characterized by insufficient anterior and lateral coverage. In general, the findings have important implications for orthopedic surgeons and radiologists dealing with diagnostic assessment of painful hips in young adults, and for surgeons planning and performing joint-preserving periacetabular osteotomies. ASSESSMENT OF ACETABULAR LABRAL TEARS IN HIP DYSPLASIA: The roles of ultrasound and clinical tests in acetabular labral tear diagnostics were established. After overcoming an initial learning curve, ultrasound investigation was highly reliable in diagnosing labral tears, whereas only a positive impingement or FABER test was reliable in identifying a labral tear. It seems that non-invasive and rapid ultrasound examination performed by an experienced examiner can potentially alter the traditional diagnostic algorithm in which magnetic resonance arthrography remains the gold standard. PERIACETABULAR OSTEOTOMY FOR SURGICAL TREATMENT OF HIP DYSPLASIA IN ADULTS: Encouraging hip joint survival and clinical outcome were reported at medium-term follow-up after periacetabular osteotomy. The small number of studies reporting the outcome beyond a 5-year follow-up is in contrast to the wide application of the periacetabular osteotomy. The performed analysis of predictors of conversion to total hip replacement following periacetabular osteotomy documented the importance of different biomechanical and degenerative factors. Knowledge about factors predicting early conversion to total hip replacement has the potential to refine patient selection and to improve treatment by periacetabular osteotomy. Cartilage thickness was documented to be preserved up to 2,5 years after periacetabular osteotomy. All but 1 hip joint had acetabular labral tears, thus indicating that the presence of labral tears does not accelerate cartilage degeneration after periacetabular osteotomy.

[Simple Pemberton's ilium osteotomy and combined unter-trochanter derotation-varisation osteotomy for developmental dysplasia of the hip]

OBJECTIVE

To retrospectively compare the therapeutic effects of simple Pemberton's ilium osteotomy and combined unter-trochanter derotation-varisation osteotomy for developmental dysplasia of the hip (DDH).

METHODS

Clinical data of 141 DDH patients who received either simple Pemberton's ilium osteotomy (n=57; 12 male and 45 female; age range 3-8 years) or combined unter-trochanter derotation-varisation osteotomy (n=84; 15 male and 69 female; age range 4-9 years) from January 2004 to January 2009 were collected. Postoperative complications, Severin's radiological outcomes and therapeutic outcomes as evaluated by Mcay criteria were compared between the two groups 2 years after operation.

RESULTS

The patients in simple Pemberton group were followed-up for 30-52 months (mean 38 months) and the patients in the combination group were followed-up for 32-51 months (mean 37 months). There were 7 cases of dislocation, 4 cases of avescular necrosis of femoral head and 5 cases of joint stiffness in simple Pemberton group vs 0 case of dislocation, contraction of the limb and ANFH,2 cases of joint stiffness in the combination group. Two years after surgery, the result as evaluated by McKay criteria was excellent in 27 cases, good in 18 cases and fair in 12 cases in simple Pemberton group vs. 52, 25 and 7 cases in the combination group. The overall clinical outcome in the combination group was better than that in simple Pemberton group. Severin X-ray evaluation showed excellent in 27 cases, good in 15 cases and fair in 15 cases in simple Pemberton group vs. 53, 22 and 9 cases in the combination group,indicating that the overall result in the combination group was better than that in simple Pemberton group.

CONCLUSION

The overall clinical outcome of the combination group is better than that of simple Pemberton group in the treatment of pediatric DDH, especially in reducing postoperative complications and functional recovery. The patients in the combination group reported a higher postoperative satisfaction as compared with those in simple Pemberton group.

The 15° face-changing acetabular component for treatment of osteoarthritis secondary to developmental dysplasia of the hip

We report the use of a 15° face-changing cementless acetabular component in patients undergoing total hip replacement for osteoarthritis secondary to developmental dysplasia of the hip. The rationale behind its design and the surgical technique used for its implantation are described. It is distinctly different from a standard cementless hemispherical component as it is designed to position the bearing surface at the optimal angle of inclination, that is, < 45°, while maximising the cover of the component by host bone.

Use of multislice computed tomography in radiological treatment of patients with hip pathology

In this paper we are presenting the application of Multislice CT Scan (MSCT) as a part of radiological treatment in a female patient with avascular necrosis of head and neck of the right femur, which occurred as a consequence of developmental hip dysplasia. The left hip joint of the patient was previously replaced by a prosthetic implant.

Macrocephaly with multiple epiphyseal dysplasia: a second example of Al Gazali-Bakalinova syndrome?

Four individuals from one consanguineous family affected with macrocephaly, multiple epiphyseal dysplasia and distinctive facies were presented by Al Gazali and Bakalinova in 1998 (1) as a distinct clinical entity. To the best of our knowledge, no other similarly affected family has been presented in the literature. Here, we present an affected macrocephalic male, from a consanguineous family, with facial anomalies, cranial MRI findings and multiple epiphyseal dysplasia findings. We believe this is the second family with a similar clinical spectrum and the same inheritance pattern as those of the family presented by Al Gazali and Bakalinova. Pectus carinatum, hip dislocation and a history of prenatal polyhydramnios have been noted as additional findings in our patient.

[Talus partitus. A case report]

An ankle bone consisting of several fragments is a rare anatomical variant of the talus, in the literature described as talus partitus or frontal split. On radiographs or CT scans it presents as two or more relatively large fragments. The term talus partitus is sometimes incorrectly used for an accessory bone that occasionally develops behind the ankle bone and is called os trigonum. Talus partitus is an unusual developmental anomaly in which the talus is partitioned although it ossifies from a single centre. The cause of its split has not been explained although this may also be due to a previous unrecognized injury. In the Slovak medical literature no report of this anomaly has been found. Here we resent the case of a 30-year-old man in whom the ankle bone split was an incidental finding. This patient also had ipsilateral developmental dysplasia of the hip. This is the first report of a patient with the two concurrently found anomalies.