Studying the long-term outcomes in developmental infant hip dislocation.

Currently the aims for treatment for late-detected developmental hip dislocation are to obtain proper alignment with good femoral head coverage and to avoid complications. In the past, closed reduction with or without traction was common however more open reductions are being performed today. Both closed and open reductions are often followed up by femoral and pelvic osteotomies. This recent study by Terjesen et al aimed to provide more information about the fifty-year outcome of adults who were treated as children for late-detected developmental dislocation of the hip. There have been no studies with this duration of follow-up and it may provide further ideas about what factors at diagnosis might help predict the long-term outcome.

This study looked at seventy-one patients (ninety hips) that were treated between 1958 and 1962 by one group of orthopedists. The patient ages ranged from two months up to five years old at the time of diagnosis. Every patient was treated with open reduction of skin traction at the facility, and the average time in traction was thirty-three days. Following traction a bilateral hip spica cast was applied which effectively casted the hips, knees and feet in slight flexion and abduction. The patients were in the spica cast for a mean time of nine and a half months. After this, further treatments included open reductions (five hips at a mean age of 25.4 months), derotational femoral osteotomy (fifty-four hips within three years of the initial traction treatment), and further reconstructive surgery after the first three years (thirty hips at a mean age of eleven years old); indicating that it was common for there to be an open reduction performed in addition to the conservative traction and spica cast treatment. Total hip replacement is also common later in life for these patients. At the time of this fifty-year follow-up study twenty-six percent of the hips had been replaced.

Interesting findings from this study include a strong association between the results of x-ray and the patient reported functional outcomes. Residual subluxation is seen in this study as a risk factor for the development of osteoarthritis, and one debatable point is how to treat such hips. It has been shown in other studies that without surgical correction such hips will eventually develop arthritis. And it remains the current policy of this particular group of orthopedists to perform a pelvic osteotomy for patients who are under ten to mitigate this risk as best possible.

Over the years the common treatment for late-detected hip dislocations remains closed reduction with traction. However a shorter time period is used and there is no longer routine femoral derotation. This has changed in the past fifty years due to various reasons, including inconvience for the families and fewer beds in the facility. The consequence of this shorter traction period has been that open reduction surgery has become much more common.

The most useful observation made from this retrospective study is the significant improvement in outcomes, both as observed on x-ray and by patient report, if the diagnosis was made before the age of one and a half years (eighteen months). Of the patients who were younger than eighteen months, only nine percent developed arthritis, whereas if the patients were older, forty nine percent developed arthritis. This is a pretty strong argument that if such diagnosis is made before eighteen months, the more conservative treatment may be quite effective.