BACKGROUND: Cotyloplasty is a technique that involves making a perforation of the medial wall of a shallow acetabulum and then inserting an acetabular cup with the medial aspect of its dome beyond the Kohler line. The purpose of this study was to evaluate the results of cementless total hip arthroplasty (THA) using cotyloplasty with focusing on the amount of medial cup protrusion. METHODS: Sixteen hips with insufficient acetabulum in sixteen patients were treated by cementless THA using cotyloplasty. The average patient age was 47 years. The diagnoses included dysplastic hip (12) and infection sequelae (4). All the patients were followed up for at least 2 years. Clinically, the Harris hip scores were assessed and radiologically, the amount of cup protrusion, the hip center movement and cup fixation were evaluated. RESULTS: The average Harris hip score improved from 57 to 94 postoperatively. The average proportion of cup surface beyond the Kohler line was 44.1% and the hip centers were medialized by an average of 23 mm. Stable fixation of the acetabular cup was achieved in all the cases except one. In this one case, migration of the cup was detected 2 weeks postoperatively and a reoperation was performed. CONCLUSIONS: Using cotyloplasty, good coverage of the acetabular cup was obtained without a block bone graft, and the hip joint centers were medialized. However, the safety margin for the amount of protrusion should be established.
Acetabulum/*pathology/radiography/*surgery ; Adult ; Arthritis, Infectious/complications/pathology ; *Arthroplasty, Replacement, Hip ; Female ; Hip Dislocation, Congenital/pathology/surgery ; Hip Joint/radiography ; *Hip Prosthesis ; Humans ; Male ; Middle Aged

BACKGROUND: Total hip arthroplasty (THA) for severe developmental dysplasia of the hip (DDH) is a technically demanding procedure for arthroplasty surgeons, and it is often difficult to reduce the hip joint without soft tissue release due to severe flexion contracture. We performed two-stage THAs in irreducible hips with expected lengthening of the affected limb after THA of over 2.5 cm or with flexion contractures of greater than 30 degrees in order to place the acetabular cup in the true acetabulum and to prevent neurologic deficits associated with acute elongation of the limb. The purpose of this study is to evaluate the outcomes of cementless THA in patients with severe DDH with a special focus on the results of two-stage THA. METHODS: Retrospective clinical and radiological evaluations were done on 17 patients with Crowe type III or IV developmental DDH treated by THA. There were 14 women and 3 men with a mean age of 52.3 years. Follow-ups averaged 52 months. Six cases were treated with two-stage THA followed by surgical hip liberalization and skeletal traction for 2 weeks. RESULTS: The mean Harris hip score improved from 40.9 to 89.1, and mean leg length discrepancy (LLD) in 13 unilateral cases was reduced from 2.95 to 0.8 cm. In the patients who underwent two-stage surgery, no nerve palsy was observed, and the single one-stage patient with incomplete peroneal nerve palsy recovered fully 4 weeks postoperatively. CONCLUSIONS: The short-term clinical and radiographic outcomes of primary cementless THA for patients with Crowe type III or IV DDH were encouraging. Two-stage THA followed by skeletal traction after soft tissue release could provide alternative solutions to the minimization of limb shortenings or LLD without neurologic deficits in highly selected patients.
Adult ; Aged ; Arthroplasty, Replacement, Hip/*instrumentation/*methods ; Female ; Femur/radiography/surgery ; Hip/radiography/surgery ; Hip Dislocation, Congenital/pathology/radiography/*surgery ; Hip Joint/pathology/radiography/surgery ; Hip Prosthesis ; Humans ; Ilium/radiography/surgery ; Male ; Middle Aged ; Orthopedic Fixation Devices ; Retrospective Studies ; Traction

Adolescent ; Child ; Female ; Hip Dislocation, Congenital ; diagnostic imaging ; pathology ; surgery ; Humans ; Male ; Osteotomy ; methods ; Pelvic Bones ; surgery ; Radiography

BACKGROUND: Some dysplastic hips with favorable radiographic parameters fail to develop normally, suggesting that we should consider cartilaginous or soft tissue structures for further information regarding the condition of the hip. The purpose of this study was to provide a clear definition of concentric reduction in developmental dysplasia of the hip (DDH) based on magnetic resonance imaging (MRI), and to determine how radiographic and MR-based parameters could be used together to treat dysplastic hips. METHODS: We studied range of motion (ROM)-MRI of 25 patients with unilateral hip dysplasia (mean age at the time of MR imaging, 44.1 months). Each ROM-MRI consisted of a set of bilateral hip scans in the following positions: neutral; abduction; abduction- internal rotation; abduction-internal rotation-flexion; and adduction. Before MR scanning, the 25 patients received the following primary treatments: closed reduction (n = 15; at a mean age of 14.5 months); and open reduction (n = 10; at a mean age of 10.0 months). The following new parameters appear to be useful in treating DDH: 1) the labral angle, the angle the labrum makes with the acetabulum; 2) the uncorrected labral deformity (ULD), the "residual deformity" (deflection of the labrum) when the affected labrum is freed from pressure in abduction; and 3) the zone of compressive force (ZCF), the region of the acetabulum through which the body weight acts on the femoral head. RESULTS: A concentrically-reduced hip is one in which the labrum points downward in the neutral position, at the same angle as that of the normal side; and in which the ZCF is zone 3, the inner acetabular zone as defined herein. The ULD and the ZCF may be determined precisely as we have done, or the physician may simply observe the changes in the orientation of the labrum and compare the changes qualitatively to the unaffected side, and likewise for the medial joint space. CONCLUSIONS: Detailed analysis of the labrum as permitted by ROM-MRI, together with acetabular index and other parameters measured from radiographs, provides important information for physicians treating childhood hip dysplasia.
Child, Preschool ; Female ; Hip Dislocation, Congenital/*diagnosis/physiopathology/radiography/surgery ; Hip Joint/pathology/physiopathology/radiography ; Humans ; Infant ; *Magnetic Resonance Imaging ; Male ; Range of Motion, Articular

BACKGROUNDTreating developmental dysplasia of the hip is often challenging. The difficulties include not only the hip surgery itself but also the treatment of the associated lower-limb valgus deformity. However, there have been very few studies on such deformity in patients with developmental hip dysplasia. In this study, we investigated the prevalence and severity of lower-limb valgus deformity, along with the relationship between the severity of valgus deformity and mechanical alterations of the hip or the ipsilateral knee.

METHODSTwo hundred and six affected lower limbs of 116 adult patients with untreated developmental dysplasia of the hip were included in the study, grouped according to the severity of hip dysplasia. Each study participant's radiographs were measured to quantitatively evaluate the mechanical axis deviation of the lower limb, and further to evaluate the prevalence and severity of the lower-limb valgus deformity. Some mechanical alterations of the hip and the ipsilateral knee were also measured on the radiographs.

RESULTSOf the affected lower limbs, 14.1% had valgus deformities. Study participants with Crowe type III hip dysplasia had the most severe deformity and the highest prevalence of deformity. Severity of valgus deformity had a strong positive correlation with the lateral migration of the femoral head but not with the superior migration. A decreased lateral distal femoral angle contributed to the lower-limb valgus deformity, and the lateral distal femoral angle had a strong negative correlation with the severity of valgus deformity.

CONCLUSIONSHip dysplasia is commonly associated with lower-limb valgus deformity, and the severity of the lower-limb valgus deformity is mostly affected by lateral migration but not superior migration of the femoral head. The valgus deformity may originate mainly in the distal femur, in addition to the hip joint itself. These findings can be taken into account when planning to treat the patients with hip dysplasia.

Adolescent ; Adult ; Aged ; Female ; Femur Head ; diagnostic imaging ; pathology ; surgery ; Hallux Valgus ; diagnostic imaging ; pathology ; surgery ; Hip Dislocation, Congenital ; diagnostic imaging ; pathology ; surgery ; Hip Joint ; diagnostic imaging ; pathology ; surgery ; Humans ; Joint Deformities, Acquired ; diagnostic imaging ; pathology ; surgery ; Male ; Middle Aged ; Radiography ; Young Adult