Slipped Upper Femoral Epiphysis (SCFE) is an orthopedic pathology caused by sliding of the superior femoral epiphysis on femoral neck through the physeal plate [1Peck DM, Voss LM, Voss TT. Slipped Capital Femoral Epiphysis: Diagnosis and Management. Am Fam Physician 2017; 95(12): 779-84.
[PMID: 28671425] ]. It is a common pathology of the hip in school aged children and adolescents occurring often during sport, accidental fall and after a trivial trauma. Anatomically, there is a shift of the femoral neck in the anterolateral direction, while the head remains fixed in the acetabulum. It is only later that the femoral head will be pushed by the neck of the femur towards the back and the bottom. Therefore, we talk about SCFE in varus [2Loder RT, Skopelja EN. The epidemiology and demographics of slipped capital femoral epiphysis. ISRN Orthop 2011; 2011: 486512.
[http://dx.doi.org/10.5402/2011/486512] [PMID: 24977061] ]. Occasionally, a valgus is observed when the proximal femoral epiphysis slips laterally and posteriorly [3Shank CF, Thiel EJ, Klingele KE. Valgus slipped capital femoral epiphysis: prevalence, presentation, and treatment options. J Pediatr Orthop 2010; 30(2): 140-6.
[http://dx.doi.org/10.1097/BPO.0b013e3181d076b6] [PMID: 2017 9561] ]. The incidence of the pathology varies from one region to another [2Loder RT, Skopelja EN. The epidemiology and demographics of slipped capital femoral epiphysis. ISRN Orthop 2011; 2011: 486512.
[http://dx.doi.org/10.5402/2011/486512] [PMID: 24977061] ]. A systematic review published in 2011 gives an incidence of 0.33 / 100,000 to 24.58 / 100,000 adolescents aged 8 to 15 years [2Loder RT, Skopelja EN. The epidemiology and demographics of slipped capital femoral epiphysis. ISRN Orthop 2011; 2011: 486512.
[http://dx.doi.org/10.5402/2011/486512] [PMID: 24977061] ]. There is a racial disparity with relatively high prevalence rates observed among Polynesians (5.6%) and black Americans (3.9%); Hispanics (2.5%) and Caucasians (1.0%). Few data has been found in the literature about an estimate of prevalence or incidence in sub-Saharan Africa (SSA) [2Loder RT, Skopelja EN. The epidemiology and demographics of slipped capital femoral epiphysis. ISRN Orthop 2011; 2011: 486512.
[http://dx.doi.org/10.5402/2011/486512] [PMID: 24977061] ].

Classically, SCFE affects an obese adolescent who most often consults for hip pain or sometimes knee pain associated with a walking disorder occurring in a non-traumatic context [4Perry DC, Metcalfe D, Costa ML, Van Staa T. A nationwide cohort study of slipped capital femoral epiphysis. Arch Dis Child 2017; 102(12): 1132-6.
[http://dx.doi.org/10.1136/archdischild-2016-312328] [PMID: 2866 3349] ]. Generally, isolated knee pain as the presenting initial complaint has been observed to be a significantly missed diagnosis with consequent diagnostic delay [4Perry DC, Metcalfe D, Costa ML, Van Staa T. A nationwide cohort study of slipped capital femoral epiphysis. Arch Dis Child 2017; 102(12): 1132-6.
[http://dx.doi.org/10.1136/archdischild-2016-312328] [PMID: 2866 3349] ]. There is variability in diagnostic accuracy between health practitioners [5Lam A, Boenerjous SA, Lo Y, et al. Diagnosing slipped capital femoral epiphysis amongst various medical specialists. J Child Orthop 2018; 12(2): 160-6.
[http://dx.doi.org/10.1302/1863-2548.12.170200] [PMID: 29707055] ]; the highest diagnostic accuracy found in radiologists (84% to 92%); orthopedic surgeons (80% to 88%) and pediatricians (48% to 78%). A study published in Denmark showed a diagnostic delay in 67% of patients when the initial consultation was made by a general practitioner or a resident physician [6Pihl M, Sonne-Holm S, Christoffersen JK, Wong C. Doctor’s delay in diagnosis of slipped capital femoral epiphysis. Dan Med J 2014; 61(9): A4905.
[PMID: 25186544] ]. All these elements mentioned above are factors that contribute to explain the diagnostic delay observed in the developed as well as developing countries. Delayed management leads to long-term complications such as avascular necrosis and early degenerative joint disease [7Marlon JA. Slipped Capital Femoral Epiphysis : a case report 2003; 20-3.]. In these countries, the financial cost is also a factor to consider. Once diagnosed, management should be instituted in an orthopedic unit.

We report here a case of a 10-year-old girl with a chronic non-traumatic pain of the right thigh. This case highlights the difficulty in the diagnosis and management of SCFE in Low and Middle-Income Countries (LMICs).

A 10-year-old girl, black African was referred to the orthopedic department of the National Social Insurance Fond hospital in Yaounde, Cameroon by a pediatrician for investigation of a persistent non-traumatic thigh pain of sudden onset for which she had been followed-up for 12 six months.

She complained for a year of a spontaneous pain of the right mid-thigh of insidious onset associated with a limping gait. The pain was permanent, rated at 5/10 on the visual analogue scale without any radiation. No notion of neither fever nor night sweats was associated with this pain, which was temporarily relieved by Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). After consulting several general practitioners and two pediatricians, a total of four plain x-rays of the thigh and an ultrasound were requested and showed no abnormal finding. Lastly, a pelvic and thigh MRI carried out revealed a SCFE before her referral. Her past history was remarkable for no chronic pathology, no sickle cell disease, and she was premenarche.

At the initial physical examination, she was fully conscious, oriented in time, place and person. Her anthropometric parameters were: a height of 130 cm, a BMI of 20 kg /m². There was no fever. The right lower limb was in abduction with slight external rotation spontaneously on inspection. A right amyotrophic was noted with a difference of one cm diameter compared to the contralateral thigh. She had no shortening. On palpation, there was no tenderness of the thigh, but tenderness on palpation of the right groin. During mobilization of the right hip, there was a limitation of the internal rotation and an increase in external rotation. There was also a limitated painful flexion of the hip. Examination of the underlying and contralateral joints was normal. Also, she had a limping gait in external rotation of the lower right limb. The rest of the general examination was normal.

An MRI requested in our health centre revealed a shift of the right femoral head, equalled to the upper third of the metaphysis with a tilt angle of 40°, there was oedema of the femoral metaphysis, and a liquid effusion of the right hip joint (Fig. 1). Hence, we made the diagnosis of a stage 2 right SCFE.

Fig. (1) MRI findings: A: Coronal view; B: Axial view.

Fig. (2) Post operative radiographs: A: Day 1; B: 6th Month; C: 12th month.

After obtaining the consent of the parents, the child underwent surgery under general anesthesia. The surgical technique chosen was open reduction and internal fixation using three pins. The postoperative course was uneventful. At Day 2 post-operation, we started the isometric mobilization of the limb. On Day 4, we started the weight bearing with axillary crutches. We discharged the patient on the day 6 post operation without any sign of surgical site infection. Full weight bearing was allowed after 6 weeks period. Clinical and radiological check-ups were one at one month, six months and one year postoperatively showed good outcome with a satisfactory bone fusion (Fig. 2). Hence, the pins were removed after one year of fixation. Her clinical examination and radiological follow-up three years after removal of the pins were satisfactory with no particular signs of complications (avascular necrosis, chondrolysis, and femoral acetabular impingement) or signs of contralateral involvement.

Hip disorders in children are frequent reasons for pediatric consultations. The causes are multiple, benign most often. But they can be severe, or functional disabling [8Karkenny AJ, Tauberg BM, Otsuka NY. Pediatric Hip Disorders: Slipped Capital Femoral Epiphysis and Legg-Calvé-Perthes Disease. Pediatr Rev 2018; 39(9): 454-63.
[http://dx.doi.org/10.1542/pir.2017-0197] [PMID: 30171056] ]. SCFE, also called upper femoral epiphysis (SUFE), is a common cause of pediatric hip disorders characterized by a displacement of the femoral head (epiphysis) on the femoral neck due to weakness in the hypertrophic zone of the growth plate. The etiology of the pathology responsible for the slip is unknown to date. However, some predisposing factors reported include obesity [10Marquez D, Harb E, Vilchis H. Slipped capital femoral epiphysis and hypothyroidism in a young adult: a case report. J Med Case Reports 2014; 8: 336.
[http://dx.doi.org/10.1186/1752-1947-8-336] [PMID: 25304936] ], male gender, history of radiation, renal insufficiency, endocrine disorder [9Loder RT, Wittenberg B, DeSilva G. Slipped capital femoral epiphysis associated with endocrine disorders. J Pediatr Orthop 1995; 15(3): 349-56.
[http://dx.doi.org/10.1097/01241398-199505000-00018] [PMID: 7790 494] ], especially hypothyroidism [10Marquez D, Harb E, Vilchis H. Slipped capital femoral epiphysis and hypothyroidism in a young adult: a case report. J Med Case Reports 2014; 8: 336.
[http://dx.doi.org/10.1186/1752-1947-8-336] [PMID: 25304936] ] or growth hormone deficiency [10Marquez D, Harb E, Vilchis H. Slipped capital femoral epiphysis and hypothyroidism in a young adult: a case report. J Med Case Reports 2014; 8: 336.
[http://dx.doi.org/10.1186/1752-1947-8-336] [PMID: 25304936] ]. In the present case, her diagnosis was missed and overlooked my several clinicians due to the rarity of SCFE, lack of prevalence studies in SSA, occurring in a female gender, whereas, the literature reports a prediction for the male gender. This cumulated to her delay in diagnosis and management. Early diagnosis of SCFE is often challenging, particularly if the patient presents initially with unspecific symptoms such as mild weakness, easy fatigability, or a limping gait with groin pain [11Busch MT, Morrissy RT. Slipped capital femoral epiphysis. Orthop Clin North Am 1987; 18(4): 637-47.
[PMID: 3313166] ]. On the other hand, the onset of illness may be abrupt due to large amount of epiphyseal displacement, where the patient is often in severe pain and is unable to walk. If the pain is mild and chronic, it is common for families to first resort to automedication with analgesics, hence, delaying seeking medical consultation and consequently late diagnosis and treatment [11Busch MT, Morrissy RT. Slipped capital femoral epiphysis. Orthop Clin North Am 1987; 18(4): 637-47.
[PMID: 3313166] ]. A similar scenario was observed in the present case, where the patient presented with long standing moderate hip pain of one year duration temporarily relieved by NSAIDs. Our findings corroborate with those of Green et al. [12Green DW, Reynolds RAK, Khan SN, Tolo V. The delay in diagnosis of slipped capital femoral epiphysis: a review of 102 patients. HSS J 2005; 1(1): 103-6.
[http://dx.doi.org/10.1007/s11420-005-0118-y] [PMID: 18751817] ], who found a 52% incidence of missed diagnosis for SCFE by primary care physicians, despite 60% having a hip and/or groin for close to 1 year after consultation

The outcome and prognosis of SCFE depends on early recognition, hence, preventing progression to a severe slip, avascular necrosis,and chondrolysis [13Kocher MS, Bishop JA, Weed B, et al. Delay in diagnosis of slipped capital femoral epiphysis. Pediatrics 2004; 113(4): e322-5.
[http://dx.doi.org/10.1542/peds.113.4.e322] [PMID: 15060261] ]. This is quite challenging because about 20% of children present with benign musculoskeletal pain at some time in their lives, Consequently, the diagnosis of SCFE can be missed or delayed especially when there is a lack of a leading history and specific physical findings [14Rogers MJ, Wainwright AM, Wilkinson NMR. Acute painful joints. Paediatr Child Health 2010; 20: 51-7.
[http://dx.doi.org/10.1016/j.paed.2009.09.017] ].

Several clinical classifications of SCFE are found in the literature. In the current practice, Fahey O'Brien has established a classification based on the duration of symptoms [15Odent T, Pannier S, Glorion C. Épiphysiolyse fémorale supérieure Datatraitesap14-40309 [Internet]. [cité 26 oct 2018]; Disponible sur: http://www.em-consulte.com/en/article/38660
[http://dx.doi.org/10.1016/S0246-0521(06)40309-0] ]. Therefore, we distinguish the acute form that have symptoms of less than three weeks duration; acute-on-chronic form and the chronic form if the symptoms last for more than three weeks. The clinical findings on limp inspection are shortening, and amyotrophy whose form varies according to the chronicity of the symptoms (Table 1). SCFE can also be classified according to the degree of stability of epiphysiolysis [16Loder RT, Richards BS, Shapiro PS, Reznick LR, Aronson DD. Acute slipped capital femoral epiphysis: the importance of physeal stability. J Bone Joint Surg Am 1993; 75(8): 1134-40.
[http://dx.doi.org/10.2106/00004623-199308000-00002] [PMID: 8354 671] ]. A stable SCFE if the patient can still walk and bear weight with or without crutches and unstable if the patient is immobilized, unable to walk. According to this description, it was in our case a girl who had chronic symptoms of more than 6 months duration. Her radiologic classification, was a stable epiphysiolysis. Indeed, the unstable form increases the risk of avascular necrosis by 9.4 times compared to the stable form [17Tosounidis T, Stengel D, Kontakis G, Scott B, Templeton P, Giannoudis PV. Prognostic significance of stability in slipped upper femoral epiphysis: a systematic review and meta-analysis. J Pediatr 2010 oct; 157(4): 674‑80-80.e1.].

Table 1
Clinical presentation according to the duration of the symptoms.

Table 2
Sensibility and specificity of imaging diagnostic test.

The diagnosis is confirmed by imaging studies, with x-ray as the first intention. Bilateral hip radiographs on anterior-posterior and Frog-leg views are generally sufficient to establish the diagnosis and to look for complications (avascular necrosis and chondrolysis). The profile view (Frog-leg) is useful at the early stage in search of a mild slip that may go unnoticed at the frontal view. It is therefore the first examination to be performed in case of hip pain or limp in the child [8Karkenny AJ, Tauberg BM, Otsuka NY. Pediatric Hip Disorders: Slipped Capital Femoral Epiphysis and Legg-Calvé-Perthes Disease. Pediatr Rev 2018; 39(9): 454-63.
[http://dx.doi.org/10.1542/pir.2017-0197] [PMID: 30171056] ]. Several signs were described on the radiographs to establish the diagnosis (Table 2). We quote the Klein's line, the modified Klein's line, the white metaphyseal sign, and the S-sign. The Klein line is a line tangent to the upper edge of the femoral neck. Indeed, in the case of SCFE, this line fails to intersect the lateral part of the proximal epiphysis. This classic definition using the Klein line showed a low sensitivity (40.3%) in diagnosing SCFE [18Green DW, Mogekwu N, Scher DM, Handler S, Chalmers P, Widmann RF. A modification of Klein’s Line to improve sensitivity of the anterior-posterior radiograph in slipped capital femoral epiphysis. J Pediatr Orthop 2009; 29(5): 449-53.
[http://dx.doi.org/10.1097/BPO.0b013e3181aa20cd] [PMID: 1956 8015] ]. According to Rebish et al. [19Rebich EJ, Lee SS, Schlechter JA. The S Sign: A New Radiographic Tool to Aid in the Diagnosis of Slipped Capital Femoral Epiphysis. J Emerg Med 2018; 54(6): 835-43.
[http://dx.doi.org/10.1016/j.jemermed.2018.01.023] [PMID: 2955 0284] ], in a more recent study published in 2018, diagnostic accuracy is best when combining the Klein's line and S-sign. Despite the need of a plain x-ray to confirm the diagnosis of SCFE, the radiographic diagnostic findings can be misread by inexperienced health personnel [14Rogers MJ, Wainwright AM, Wilkinson NMR. Acute painful joints. Paediatr Child Health 2010; 20: 51-7.
[http://dx.doi.org/10.1016/j.paed.2009.09.017] ], as seen in our patient in whom a total of four x-rays of the hip were requested and the radiographic diagnosis missed each time.

CT and MRI scans be used when radiographs are inconclusive and SCFE is still suspected [20Thawrani DP, Feldman DS, Sala DA. Current Practice in the Management of Slipped Capital Femoral Epiphysis. J Pediatr Orthop 2016; 36(3): e27-37.
[http://dx.doi.org/10.1097/BPO.0000000000000496] [PMID: 2592 9770] ]. MRI may be used to assess blood supply of the femoral epiphysis; therefore, it can reveal head avascular necrosis and chondrolabral damage. However, the high cost of these examinations is often a deplored obstacle to timely diagnosis of this condition in our resource-poor settings. Imaging, including radiography, can also be used to classify the patient according to the stage of severity of SCFE (Table 3). These classifications have an impact on the choice of the therapeutic modality and the prognosis (Table 3). Chronic evolution, unstable form, severe displacement are independent factors of poor prognosis in terms of Avascular necrosis (AVN) [21Ulici A, Carp M, Tevanov I, Nahoi CA, Sterian AG, Cosma D. Outcome of pinning in patients with slipped capital femoral epiphysis: risk factors associated with avascular necrosis, chondrolysis, and femoral impingement. J Int Med Res 2018; 46(6): 2120-7.
[http://dx.doi.org/10.1177/0300060517731683] [PMID: 29210310] ], chondrolysis, osteoarthritis or FAI.

The treatment of this pathology is essentially surgical. It aims to stabilize the proximal epiphysis in order to stop the progression of sliding and avoid complications [22Gutman IM, Gilbert SR. Trends in slipped capital femoral epiphysis: is the rate declining? J Child Orthop 2018; 12(5): 428-33.
[http://dx.doi.org/10.1302/1863-2548.12.180081] [PMID: 30294366] ]. It depends on the stability and the degree of severity of the slip [23Wright J, Ramachandran M. Slipped Capital Femoral Epiphysis: The European Perspective. J Pediatr Orthop 2018; 38(Suppl. 1): S1-4.
[http://dx.doi.org/10.1097/BPO.0000000000001161] [PMID: 2987 7936] ]. In stable forms [24Naseem H, Chatterji S, Tsang K, Hakimi M, Chytas A, Alshryda S. Treatment of stable slipped capital femoral epiphysis: systematic review and exploratory patient level analysis. J Orthop Traumatol 2017; 18(4): 379-94.
[http://dx.doi.org/10.1007/s10195-017-0469-4] [PMID: 28831651] ], in situ pinning with a single crew is the surgical fixation technique mostly used by orthopedic surgeons according to a survey conducted by Wight [23Wright J, Ramachandran M. Slipped Capital Femoral Epiphysis: The European Perspective. J Pediatr Orthop 2018; 38(Suppl. 1): S1-4.
[http://dx.doi.org/10.1097/BPO.0000000000001161] [PMID: 2987 7936] ]; especially when it is a mild to moderate stable form. In unstable forms, there is no consensus in the management regarding delay and therapeutic options [24Naseem H, Chatterji S, Tsang K, Hakimi M, Chytas A, Alshryda S. Treatment of stable slipped capital femoral epiphysis: systematic review and exploratory patient level analysis. J Orthop Traumatol 2017; 18(4): 379-94.
[http://dx.doi.org/10.1007/s10195-017-0469-4] [PMID: 28831651] ].The treatment differs according to the specialized hospitals, or even within the same structure. Therefore, the therapeutic options vary according to the stage of severity, the approach, the possibility of reduction, the type of implants, the duration of evolution of symptoms before management. Regarding the timing of the treatment, a systematic review and meta analysis [25Alshryda S, Tsang K, Chytas A, et al. Evidence based treatment for unstable slipped upper femoral epiphysis: Systematic review and exploratory patient level analysis. Surgeon 2018; 16(1): 46-54.
[http://dx.doi.org/10.1016/j.surge.2016.04.001] [PMID: 27255978] ] showed an avascular necrosis rates of 6%, 52% and 7% when the interventions were performed within 24 hours, between 24 and 72 hours, and after 72 hours after the onset of symptoms respectively. Table 4 presents the different therapeutic options with prognosis in patients with a stable or unstable form.

In our clinical case, the treatment option chosen was in situ fixation with 3 pins. Post operative radiographs performed did not reveal any signs in favor of complications. Osteonecrosis or avascular necrosis was suspected in case of collapse of the femoral head, sclerosis, and cyst formation. Chondrolysis when there is narrowing of the femoroacetabular space; and Femoroacetabular Impingement (FAI) when we see an abnormal contact between the proximal femoral metaphysis and the acetabular rim [26Kienstra A, Macias CG. Evaluation and management of slipped capital femoral epiphysis (SCFE). In: Up To Date. Waltham, MA: UpToDate Inc. 2018 [cité 11 nov 2018]. Disponible sur: https://www. uptodate.com]. Prophylactic treatment of the contralateral side is also a therapeutic option although it can lead to complications. The elements to be taken into account are [27Hansson G, Nathorst-Westfelt J. Management of the contralateral hip in patients with unilateral slipped upper femoral epiphysis: to fix or not to fix--consequences of two strategies. J Bone Joint Surg Br 2012; 94(5): 596-602.
[http://dx.doi.org/10.1302/0301-620X.94B5.28322] [PMID: 2252 9076] ]: an atypical presentation, the severity of slippage on the sick side, the risk of losing sight of the patient during the follow up. All these elements must be weighed with the risks of complications inherent to the treatment: chromolysis, avascular necrosis, postoperative infections and the risk of fracture.

Table 3
Stage of severity and prognosis.

Table 4
Therapeutic options for stable and unstable SCFE.

SCFE is a pathology of the adolescent occurring during his pubertal growth spurt. It is most often a child with chronic pain, partial or complete functional impotence of the affected limb and with a diagnostic delay. This delay in diagnosis coupled with the high cost of surgical treatment in low-income countries are obstacles to the management of this pathology.