OPTIONS

Once a diagnosis of SCFE is made, treatment is indicated to prevent slip progression^14–16 and to avoid complications, especially AVN and chondrolysis. Multiple treatment options are available, each having specific advantages and disadvantages. These options are divided into those for patients with stable SCFE and those for patients with unstable SCFE.

Treatment options for a stable SCFE include: (1) in situ stabilization with a single screw^8,9,17-21 or multiple pins^17,22–25; (2) epiphyseodesis^25–30; (3) open reduction with corrective osteotomy through the physis and internal fixation^{18,22,30–39}; (4) basilar neck osteotomy^40–42; (5) intertrochanteric osteotomy^24,42-46; and (6) surgical dislocation of the hip with transphyseal callus removal, reduction, and fixation.^47–51

The treatment of a patient with unstable SCFE is quite controversial. Treatment options include internal fixation with or without reduction and joint decompression, epiphysiodesis, and open reduction with corrective osteotomy through the physis and internal fixation. Considerable discussion has occurred regarding the timing (emergent or urgent reduction vs. elective) of the reduction, the magnitude of reduction (incidental reduction [improvement in the SCFE that occurs with positioning the patient on the operating table] vs. a complete reduction), the role of joint decompression, and the number of internal fixation devices.

LEVELS OF EVIDENCE

The treatment of SCFE has been one of gradual evolution over time. The available studies (Table 32-1) are, at best, Level III; no randomized, controlled studies and few prospective comparative studies involve SCFE. For this reason, I review the few Level III and the most appropriate Level IV series, compare and contrast them regarding long-term outcomes and complications, synthesize the data, and propose as best as possible the optimal treatment of SCFE.

As a background to considering the various different treatments for SCFE, it is first necessary to understand the long-term natural history of the untreated SCFE and the long-term outcomes from SCFEs treated many years ago. The two major concerns in the untreated individual with SCFE are the risk for further progression and the risk for degenerative joint disease in adult life. Few long-term studies of patients with SCFE and even fewer untreated individual are included in these series.^{11,22,52–56} Ordeberg and researchers⁵⁷ studied a series of patients with SCFE without primary treatment 20 to 40 years after diagnosis. Few patients had restrictions in working capacity or social life. However, there was a risk for slip progression as long as the physis remained open.⁵⁸ Carney and coauthors²² reported on 35 patients with SCFE who were initially observed; in 6 hips (17%), gradual progression occurred, with 5 becoming severe. An additional 11 patients had an acute episode superimposed on the chronic SCFE; all progressed to severe displacement and required surgical stabilization.

Howorth⁵⁹ (Level V evidence) states that SCFE is likely the most frequent cause of degenerative joint disease of the hip in middle life, and a common source of pain and disability. This is not necessarily supported by other studies. The number of patients with known SCFE is low (average 5%) in reviewing large series of patients with degenerative joint disease.^60–62 The severity of deformity in the untreated SCFE is known to correlate with the long-term prognosis regarding degenerative joint disease.^{22,52, 54, 56, 63, 64} Oram⁵⁴ reports on 22 patients with untreated SCFEs; patients with moderate SCFEs retained good function for years, whereas patients with severe SCFEs experienced development of degenerative joint disease within 15 years. Jerre^63,64 and Ross and colleagues⁵⁶ report increasingly poor results with longer follow-up periods; many patients responded well early on but experienced development of increasing symptoms and decreasing function with increasing age. Carney and Weinstein⁵² studied the natural history of the untreated, chronic SCFE in 31 hips at an average follow-up period of 41 years. The average Iowa Hip Rating was 92 in the 17 patients with mild SCFE, 87 in the 11 patients with moderate SCFE, and 75 in the 3 patients with severe SCFE. Although a patient with a mild SCFE appears to have a favorable prognosis, patients with moderate and severe SCFE have a high incidence of degenerative joint disease. Poor results, however, can occasionally be seen even with minimal SCFEs.^{11,22, 52, 56} In summary, the natural history of chronic (stable) SCFE is favorable provided that displacement is mild and remains so. Thus, all treatments should stabilize the SCFE and prevent complications.

What are the long-term historical results of treatment? Wilson and coworkers⁶⁵ reviewed 300 hips treated between 1936 and 1960. Good results were seen in 81% of those treated with in situ fixation and in 60% of those with deformity correction. Hall⁵³ reviewed 138 patients; excellent results were seen in 80% of those treated with multiple pin fixation; realignment with osteotomy of the femoral neck resulted in a 38% AVN rate with 36% poor results. Ordeberg and researchers⁶⁶ reviewed 44 patients with untreated SCFE followed for more than 30 years. Symptomatic treatment or fixation in situ gave excellent results, with only 2% needing a secondary reconstructive procedure. Closed reduction or spica cast treatment had a combined rate of AVN and chondrolysis of 13%, with 35% needing a reconstructive procedure; femoral neck osteotomy resulted in a combined rate of AVN and chondrolysis of 30%, with 15% needing a reconstructive procedure.⁵⁷ Carney and coauthors²² report on 155 hips at a mean follow-up of 41 years. Poorer results were associated with more severe slips and realignment; chondrolysis (16%) and AVN (12%) were more common with increasing slip severity. All these long-term studies support the use of in situ fixation as the treatment of choice for SCFE regardless of slip severity. Realignment was associated with significant complications and poorer results. It must be remembered, however, that the surgical fixation techniques and imaging modalities used in these historical series are much different from those currently used.

Stable Slipped Capital Femoral Epiphysis

The incidence rates of AVN range from 0% to 10%, of chondrolysis from 0.8% to 16%, and slip progression from 0.5% to 5.7% (Tables 32-2, 32-3, and 32-4). The lowest rates of AVN, chondrolysis, and slip progression in aggregate are those treated with a single central screw (see Table 32-4). The advantages of single-screw fixation for a patient with a stable SCFE include a high success rate, a low incidence rate of further slippage, and a low incidence rate of complications.^{8,67, 68}

TABLE 32-2 Treatment Outcomes in Stable, Idiopathic Slipped Capital Femoral Epiphysis

TABLE 32-3 Compiled Results of Outcomes for Different Methods of Treatment in Stable Idiopathic Slipped Capital Femoral Epiphysis

TABLE 32-4 Summary of Literature Results in the Treatment of Stable, Idiopathic Slipped Capital Femoral Epiphysis

Epiphysiodesis attempted to avoid the complications associated with internal fixation (unrecognized pin protrusion, damage to the lateral epiphyseal vessels, and hardware failure); however, the fixation provided by the bone graft was less secure than that with internal fixation, having a 5.7% incidence rate of slip progression. As a result of this higher slip progression rate and other disadvantages (blood loss, large scar, long anesthesia time, neck and subtrochanteric fracture), epiphysiodesis is no longer the first choice of treatment for an SCFE.

Osteotomies are used in an attempt to correct the deformity associated with SCFE. The overall incidence rate of both chondrolysis and AVN in 350 cases of physeal/cuneiform osteotomy compiled from the literature was 10%. Because of this high risk for AVN and subsequent poor results in most series, a physeal cuneiform osteotomy is not recommended in the treatment of SCFE. A compensating base-of-neck osteotomy is an attempt to maintain the advantages of a physeal osteotomy (deformity correction) but with a lower risk for AVN. Indeed, the incidence rate of AVN is less with basilar neck osteotomies compared with the cuneiform osteotomy (10% vs. 1%). The intertrochanteric osteotomy is an attempt to improve hip motion, obtain some correction of the deformity (albeit a compensatory correction), and completely avoid AVN. The compiled results demonstrate that AVN still occurs with a 2.2% incidence rate and also carries a significant risk for chondrolysis (11.9%). The results of intertrochanteric osteotomy using the Southwick technique are much poorer than those of in situ single-screw fixation.^{43,44, 69} The simpler Imhäuser flexion intertrochanteric osteotomy^{24,45, 46} has replaced the Southwick osteotomy. Because it is not a valgus, limb-lengthening osteotomy, the increase in joint pressure created by the traditional Southwick osteotomy, a likely cause of chondrolysis, is avoided. When comparing the results (Table 32-5) between the flexion and Southwick types of osteotomies, the rate of AVN and chondrolysis is 2.5% (5/198) and 4.9% (7/142) for the flexion osteotomy and 0% (0/112) and 15.2% (17/112) for the Southwick osteotomy. Although the rate of chondrolysis is lower for the flexion osteotomy, there is an increase in the rate of AVN with the flexion osteotomy.

TABLE 32-5 Comparisons between the Flexion and Southwick Types of Intertrochanteric Osteotomies in the Treatment of Stable, Idiopathic Slipped Capital Femoral Epiphysis

In conclusion, when reviewing all the evidence and published series to date, it is clear that the optimal treatment for the stable, idiopathic SCFE is single central screw fixation (Figs. 32-1 and 32-2).

FIGURE 32-1 The incidence of cumulative complications for various treatment methods in idiopathic, stable slipped capital femoral epiphysis (SCFE), as derived from multiple series in the literature. BNO, basilar neck osteotomy; EPI, epiphysiodesis; ITO, intertrochanteric osteotomy; MPF, in situ multipin fixation; PHYO, physeal/cuneiform osteotomy; SCS, in situ single central screw fixation; SPICA, spica cast.

FIGURE 32-2 The anteroposterior (AP) (A) and frog-lateral (B) radiographs of a child with a right slipped capital femoral epiphysis (SCFE). Treatment was provided by a single central screw in the center of the epiphysis and perpendicular to the physis in both the AP (C) and frog-lateral (D) positions.