Yoichi Seto

Bilateral humeral lengthening in achondroplasia

Twenty humeral lengthenings were done on 10 achondroplastic dwarfs using the Ilizarov circular fixator. There were five female and five male patients from 6 years 11 months to 17 years 8 months of age (mean, 12 years 10 months) at the time of the operation. Mean length obtained was 7.8 cm (range, 3.5 cm–10 cm). External fixation time ranged from 105 days to 368 days (mean, 221 days). Healing index averaged 30 days/cm (27 days/cm when two patients with radial nerve palsy were excluded). Two half pins in one patient required replacement. Two humeral fractures occurred, one while in the fixator and the other after removal of the apparatus. Transient radial nerve palsy developed during lengthening in two patients, and lengthening was discontinued. Symptoms of radial nerve palsy resolved completely in both patients, but one patient required an additional surgery to explore the radial nerve for persistent paresthesia of the forearm. Although preexisting loose shoulders deteriorate during lengthening and sometimes cause pain and discomfort, they always resolve spontaneously as lengthening proceeds. Bilateral humeral lengthening was very effective for improving function and overall proportion in patients with achondroplasia.

Arthroscopy for slipped capital femoral epiphysis.

Arthroscopy was performed in five hips with slipped capital femoral epiphysis (SCFE) before pinning in situ. Arthroscopy disclosed erosion of acetabular cartilage in the anterosuperior region and damage to the posterolateral aspect of the acetabular labrum. Cartilaginous erosion and transverse cleft were identified on the anterior surface of the femoral head. These findings support the hypothesis that all pathomechanisms of SCFE are caused by traumatic factors. Arthroscopy for SCFE is also clinically useful in reducing hip pain. Arthroscopy performed simultaneously with pinning in situ can permit early exercise of the joint.

Dislocation and subluxation during femoral lengthening

Femoral lengthening by callus distraction was performed on 26 femurs of 18 patients with various disorders between 1988 and 1992. Age at surgery ranged from 6 to 17 years (13 years on average). The amount of lengthening varied from 2 to 7.5 cm (mean 5 cm). Follow-up evaluation of femoral-head displacement was based on the change of center-edge (CE) angle. The hips were divided into two groups based on the preoperative CE angle; one group consisted of 14 hips with a CE angle > 20 degrees and the other group consisted of 12 hips with an angle of < or = 20 degrees. In the first group, none of the hips deteriorated; however, five of 12 hips in the second group did deteriorate. One hip developed complete dislocation and the other four showed a decrease in the CE angle. Four of five deteriorated hips had a history of congenital dislocation of the hip and the other had multiple epiphyseal dysplasia. In cases in which the CE angle is < or = 20 degrees preoperatively, bony procedures such as innominate osteotomy should precede femoral elongation.

Prediction of reduction in developmental dysplasia of the hip by magnetic resonance imaging.

The acetabular rim of 33 hips in 29 patients with developmental dysplasia of the hip was evaluated using magnetic resonance imaging (MRI). The hips were classified into the following three groups according to the shape of the acetabular rim: 12 hips with sharp acetabular rim (group 1), 13 hips with dysplastic and round acetabular rim (group 2), and eight hips with inverted acetabular rim (group 3). The position of the femoral head with the hip flexed and abducted was also recorded, according to the criteria proposed by Suzuki. They were all treated initially with the Pavlik harness. All group 1 hips were successfully reduced with the Pavlik harness, whereas in group 2 hips, all but three hips were reduced. In all group 3 hips, reduction was not successful. MRI provided useful information regarding the probability of reduction with the Pavlik harness.

Sequential magnetic resonance imaging in slipped capital femoral epiphysis: assessment of preslip in the contralateral hip.

Thirty-three images using magnetic resonance imaging (MRI) in 10 patients with slipped capital femoral epiphysis were evaluated. The MRI of affected hips delineated typical widening of the physis. Sequential MRI demonstrated the process of premature closure of the physis developing from the posterior portion anteriorly. In 4 of the 10 asymptomatic contralateral hips, physeal widening was clearly observed in the center or posteromedial region of the physis on T1-weighted images. We performed prophylactic pinning for the four cases showing physeal widening on MRI, and none of the other cases developed a slip. MRI accurately documented detailed features of slips, as well as physeal changes, and may provide indicative information on prophylactic pinning for contralateral hips.

Three-dimensional spinal deformity in scoliosis associated with cerebral palsy and with progressive muscular dystrophy.

The authors analyzed lateral deviation, anteroposterior deformity, and rotation of the spinal column of 11 patients with scoliosis associated with cerebral palsy (CP) and 11 patients with progressive muscular dystrophy (PMD). There was a correlation between the magnitude of Cobb angle and that of the vertebral rotation in scoliosis associated with both CP and PMD, but the ratio of spinal rotation to Cobb angle in the former was lower than that in the latter. The magnitudes of thoracic kyphosis and of lumbar lordosis were not correlated with Cobb angle in either group, but the sagittal plane deformity in the CP patients was less severe than that in the PMD patients, and the latter demonstrated kyphosis of the lumbar spine and lordosis of the thoracic spine.

Location of the femoral head in developmental dysplasia of the hip: three-dimensional evaluation by means of magnetic resonance image.

By using magnetic resonance imaging, we analyzed the position of the femoral head in 21 hips of 21 infants with developmental dislocation. The femoral head changed its location according to the hip position. In type A dislocation, the head was anterior to the acetabulum when the hip was extended, and it was posterior when the hip was flexed. There was wide contact area between the femoral head and the acetabulum in any hip position. In type B, the head was on the rim of the acetabulum when the hip was extended. When the hip was flexed, the head was on the posterior rim of the acetabulum, and there was no contact between the femoral head and acetabular cartilage. Some heads slipped into the socket with a click phenomenon when the hip was flexed/abducted. In type C dislocation, the head was on the edge of the acetabulum when the hip was extended. When the hip was flexed, the head moved posteriorly, and it was completely out of the socket.

Early characteristic findings in bowleg deformities: evaluation using magnetic resonance imaging.

We used magnetic resonance imaging (MRI) to evaluate bowleg deformities in infancy. Twenty-five tibiae of 13 infants were examined and divided into two groups based on MRI findings: group A had high intensity area in the medial epiphyseal cartilage on T2-weighted images. Group B had depression of medial physis and abnormal signal in the perichondrial region in addition to the epiphyseal lesion. At the final follow-up, all cases in group A demonstrated normal lower leg alignments, whereas five cases in group B showed characteristic roentogenographic findings of Blounts disease. The improvement rate of metaphyseal-diaphyseal angle was correlated with this classification. These findings suggested that abnormal findings in physis and perichondrial region might be preliminary findings in early stage of Blounts disease. The high intensity areas in the medial epiphyseal cartilage were commonly found among the cases with bowing deformities, which suggested that there might be a common pathomechanism between physiologic bowing and infantile Blounts disease.

Surgical Treatment for Permanent Dislocation of the Patella in Adults

Permanent dislocation of the patella in adults is a rare condition that presents with complete irreducible lateral dislocation of the patella, combined with secondary changes, such as valgus deformity and leg-length discrepancy. Because these secondary changes cannot heal spontaneously after skeletal maturation if left untreated, the patients frequently possess pathology not limited to the knee joint and extending to the whole lower extremity, such as malalignment or leg-length discrepancy, that can develop into osteoarthritis of the knee. However, to our knowledge, few surgeons advocate the significance of correcting the malalignment in treating adult patients. We treated a 34-year-old woman with permanent dislocation of the patella in a 2-stage surgery, consisting of first-stage correction of valgus deformity and limb shortening using a Ilizarov external fixator and second-stage realignment of the dislocated patella over the trochlea. A follow-up examination conducted 3 years after the second operation revealed plantigrade gait with normal alignment of the lower extremity without limping and medial thrust. The patella was tracking centrally in the patellofemoral groove. Radiographs showed a neutral mechanical axis of the lower extremity, no evidence of patellar subluxation, and no deteriorating osteoarthritic changes at the tibiofemoral joint. This case highlights the importance of correcting secondary changes, such as valgus deformity and leg-length discrepancy, to reduce the risk of future osteoarthrosis and postoperative dislocation, especially when these deformities are substantial.