There was a recent study at the Mayo Clinic in Rochester, Minnesota that may have some information to answer your questions. They took a look at the long-term results for patients who were treated for slipped capital femoral epiphysis (SCFE) with in situ pinning.
In situ pinning means to pin the epiphysis “in position” where it has slipped. But it is not put back in its normal anatomic place. So there are some questions about how well this approach works. What happens years down the road when the growth center fuses in a nonanatomic position?
The Mayo surgeons observed that patients who had the in situ pinning still complained of persistent pain, stiffness, and difficulty with movement. This was true even when the slip was considered “mild.” To find out more about why this might be happening, they reviewed the medical records (including X-rays) and telephoned 105 patients who had in situ pinning of the hip as children/teens. Patients were interviewed and completed surveys over the phone answering questions about pain, mental and physical health, and hip stiffness and dysfunction.
They gathered information about patients who had to have further surgery after the pinning procedure. The type of surgeries were reported (femoral osteotomy, surgical hip dislocation, total hip replacement). They also evaluated the data to find risk factors that might predict who would have ongoing pain and disability. Here’s a quick summary of what they found:
A closer look at the data showed no predictive risk factors to help surgeons plan treatment for these patients. They simply don’t know why a mild slip would result in such severe consequences for some patients after in situ pinning but not for all.
On the basis of these results, the Mayo surgeons still use in situ pinning for mild SCFE. They perform the realignment procedures on young adults with disabling symptoms. And they recommend further study to sort out who should have what treatment.
For example, which children will benefit the most from in situ pinning? And who should have surgery early on to correct the deformity? Early reconstructive surgery is designed to prevent disabling hip pain and stiffness from early arthritis. Is there some way to predict early on who might end up with these complications? There is a need to further understand SCFE and the results of current management while developing improved treatment techniques.