Slipped capital femoral epiphysis or SCFE is the most common adolescent hip disease . It is associated with obesity and has a higher incidence among black, Hispanic and Polynesian racial groups. It develops between 12-16 years in boys and 10-14 years in girls.

Various Modes of Treatment

Treatment of SCFE is aimed at arresting slippage and preventing complications such as avascular necrosis and chondrolysis.

The most widespread treatment for SCFE is percutaneous in situ fixation using a single screw, which has produced good results. This has largely replaced open bone-peg epiphysiodesis with or without corrective femoral osteotomy. This older technique popular in the 1950s and 1960s had the advantage of closing the physis quickly and thus preventing any further displacement of the slipped epiphysis.  It also avoided having to use screws and pins near the joint, as well as obviating screw removal. It fell out of favor largely due to the risk of recurrent slippage.

The most important complication of SCFE in later life is the risk of premature osteoarthritis. This condition manifests only during the fourth or fifth decades, however. For this reason, systematic studies are required to predict the course of events following the onset of this condition.

Another study points out that while in situ pinning produces excellent outcomes in mild to moderate slips even after decades, in terms of radiology and function, open reduction and internal fixation is a better technique for severe slips with regard to long-term outcome. The longest period of follow up covered 41 years, however, and found no significant difference between in situ pinning, spica cast, or femoral osteotomy. Each method had an average incidence of osteoarthritis of almost 30% after 20 years. In contrast, failure to arrest epiphyseal slippage was increased, as was the rate of complications, when bone-peg epiphysiodesis was utilized.

Femoral osteotomy to realign the femoral neck and head has also been inconsistent with respect to results. In addition, the rate of osteoarthritis is higher, about 65% after 28 years of follow up. Another study on moderate to severe slips treated with realignment found that almost 60% of patients eventually required some type of hip fusion or replacement, or suffered severe osteoarthritis.

Prophylactic pinning of the opposite hip has been practiced widely because of the high rate of bilateral SCFE with the second hip becoming symptomatic within 18 months of the first. However, radiographic follow up in one study revealed that only a minute percentage of contralateral hips developed osteoarthritis over the long term. S ome specialists are of the view that this precaution is unnecessary.

Harris Hip Score

Following adequate treatment of SCFE, over 90% of patients reported relief from pain, as well as being able to avoid a total hip replacement. In several studies, the radiographic outcome was found to correlate with patient scores such as the Harris Hip Score (HHS) which reports on daily activities, pain, limping, negotiating stairs, and sitting, as well as clinical examination results measuring the hip range of motion. n one study, no patient developed osteoarthritis if the HHS was 82 or more.

Slip Severity

Following in situ fixation of SCFE, hips with a worse degree of slip at the onset had a more turbulent course than those with mild to moderate slips. This was irrespective of age at the time of operation, gender, the hip affected, the number of pins used or the term of follow up. Thus the greater the severity of the slip, the worse the physical and social functioning, the pain, and the greater the likelihood of total hip replacement or hip fusion, as well as grade 3 osteoarthritis.

Among severe slips, those with chronic slips on which acute symptoms were superimposed had better long-term outcomes compared to those with chronic slips even when they were of the same grade of severity. This suggests that surgery remedies the slip such that the grade improves to a milder one.

However, some other studies have concluded that milder slips were equally prone to bad outcomes with respect to hip joint pain and limitation of movement at this joint. The apparent paradox is explained by one hypothesis that patients with lower grades of slip compensate for the deformity by changing their habits , reducing their quality of life.

Predictive Factors

Some predictive factors have been developed to measure the risk of osteoarthritis, such as:

1. Severe slippage of the epiphysis
2. Reducing displacement in chronic epiphyseal slippage with damage
3. Presence of epiphyseal necrosis
4. Presence of chondrolysis
5. Any major complications of SCFE

In conclusion, early diagnosis with adequate treatment will help to avoid hip problems in later life. The risk of a poor outcome increases with delay in treatment and consequent worsening of the severity of slippage.