A native of North Carolina, Thomas B. Dameron, Jr. (Fig 1) attended the Citadel and the University of North Carolina before receiving his medical degree from Duke University School of Medicine in 1947. After an internship in Baylor University Hospital, Dameron spent some time at the Grady Memorial Hospital in Atlanta before beginning his orthopaedic residency at the Johns Hopkins Hospital. He completed his orthopaedic residency in 1952. After military service in Georgia and Maryland, he opened his practice in Raleigh, NC.
While maintaining an active private practice, Dameron served on the clinical faculty of the orthopaedic services at Duke University and the University of North Carolina. He also was active in the affairs of the Wake Memorial Hospital and the Rex Hospital. Dameron was a member of numerous orthopaedic societies, including the American Orthopaedic Association and has been president of the Southern Medical Association.
The following article called attention to the soft tissue injuries that frequently accompany dislocations of the hip and are responsible for problems during the reduction of hip dislocations.
Leonard F. Peltier, MD, PhD
Posterior dislocation of the hip, unassociated with a fracture, is not usually difficult to reduce if there is adequate relaxation from anaesthesia. When the acetabular labrum is torn and caught between the femoral head and acetabulum, satisfactory closed reduction is impossible.
When a femoral head dislocates posteriorly, it must go through a defect in the capsule between the cartilaginous labrum and the acetabulum or through the bony posterior portion of the acetabulum. When the cartilaginous labrum is separated from the acetabulum by the femoral head, it may be displaced in a manner similar to a bucket-handle tear in a knee meniscus. If the femoral head brings the torn cartilage ahead of it into the acetabulum as it is being reduced, a derangement occurs which prevents anatomical reduction and necessitates surgical intervention.
R.E.W., a white male, thirty years old, was brought to the emergency room on May 18, 1957, after having been injured in an automobile accident. Roentgenograms of his pelvis revealed that the right hip was dislocated posteriorly. The hip was manipulated under spinal anaesthesia. It was noticed that, as the femoral head was replaced in the acetabulum, there was not the usual clunking sound. Furthermore, the hip was relatively unstable and redislocated when flexed to 45 degrees. Roentgenograms made after manipulation revealed that the femoral head was opposite the acetabulum but that the joint space was wider on the right side. It was difficult to get a satisfactory lateral roentgenogram because of the discomfort of the patient and instability of the hip. The femoral head was opposite the acetabulum but was not well seated. Soft-tissue interposition was suspected and operation was performed May 21, 1957.
The hip was approached through a posterior Osborne incision. A T-shaped tear was seen in the capsule. The hip redislocated posteriorly easily. With strong traction on the femur, the cartilaginous labrum could be seen within the joint. It was pulled out to its normal position with a blunt hook. Two holes were then drilled into the acetabulum, and the cartilaginous labrum was sewn to the bone with chromic catgut sutures. After this was done, the hip was stable beyond 90 degrees of flexion. Buck’s traction was applied postoperatively. On the second postoperative night, disorientation caused the patient to remove the traction and get out of bed. This action had no apparent harmful effect on the hip. He was allowed to walk with crutches after three weeks, and began full weight-bearing after six weeks.
The patient returned to work in August 1957 and when last examined on August 23, 1958, was working regularly. He had very little pain and a full range of motion of the hip.
The role of an intervening acetabular labrum preventing reduction of a posterior dislocation of the hip has not been recorded in the English literature except for the report of Paterson. Incarceration of a bone fragment in the acetabulum has long been recognized. It is seldom overlooked on roentgenographic examinations. There is unanimity in recommending operative treatment for this condition. A torn acetabular labrum incarcerated between the joint surfaces is more difficult to diagnose and unless specifically looked for may go untreated.
Paterson stated that in his patient with soft-tissue interposition (Case I), the hip was quite stable. Apparently the hip is less stable if the femoral head does not seat fully into the acetabulum due to a defect in the posterior buttress of the acetabulum, for the patient’s hip redislocated when flexed to more than 45 degrees. After dislocating in this position the femoral head could be brought back into the acetabulum with ease, but the clunk which is characteristic of the dislocated hip was not heard. When this clunk is not heard during the reduction of a dislocated hip an intervening torn acetabular labrum should be suspected and an anteroposterior roentgenogram of the pelvis and both hips obtained.
A difference in the width of the joint spaces suggests soft-tissue interposition. At surgery when the labrum was reattached it seemed to serve a useful purpose in preventing redislocation of the femur. On the second postoperative night this patient sat up, got out of bed, and walked, with no apparent harm to the hip. Although Paterson excised the torn labrum, I feel that this strong structure has an important function and should be replaced if possible.
A tear of the acetabular labrum with interposition following the reduction of posterior dislocation of the hip should be suspected when: (1) the femoral head does not clunk into the acetabulum at the time of the reduction, (2) the hip is unstable after manipulation even though there is no fracture, and (3) the roentgenograms of the pelvis show the femoral head to be resting further from the acetabulum on the affected side than on the non-affected side. The fibrocartilaginous labrum should be reattached to the acetabulum.
Joseph C. McCarthy, MD—Guest Editor