Aims. The aim of this study was to inform the epidemiology and treatment of slipped capital femoral epiphysis (SCFE). Methods. This was an anonymized comprehensive cohort study, with a nested consented cohort, following the the Idea, Development, Exploration, Assessment, Long-term study (IDEAL) framework. A total of 143 of 144 hospitals treating SCFE in Great Britain participated over an 18-month period. Patients were cross-checked against national administrative data and potential missing patients were identified. Clinician-reported outcomes were collected until two years. Patient-reported outcome measures (PROMs) were collected for a subset of participants. Results. A total of 486 children (513 hips) were newly affected, with a median of two patients (interquartile range 0 to 4) per hospital. The annual incidence was 3.34 (95% confidence interval (CI) 3.01 to 3.67) per 100,000 six- to 18-year-olds. Time to diagnosis in stable disease was increased in severe deformity. There was considerable variation in surgical strategy among those unable to walk at diagnosis (66 urgent surgery vs 43 surgery after interval delay), those with severe radiological deformity (34 fixation with deformity correction vs 36 without correction) and those with unaffected opposite hips (120 prophylactic fixation vs 286 no fixation). Independent risk factors for avascular necrosis (AVN) were the inability of the child to walk at presentation to hospital (adjusted odds ratio (aOR) 4.4 (95% CI 1.7 to 11.4)) and surgical technique of open reduction and internal fixation (aOR 7.5 (95% CI 2.4 to 23.2)). Overall, 33 unaffected untreated opposite hips (11.5%) were treated for SCFE by two-year follow-up. Age was the only independent risk factor for contralateral SCFE, with age under 12.5 years the optimal cut-off to define ‘at risk’. Of hips treated with prophylactic fixation, none had SCFE, though complications included femoral fracture, AVN, and revision surgery. PROMs demonstrated the marked impact on quality of life on the child because of SCFE. Conclusion. The experience of individual hospitals is limited and mechanisms to consolidate learning may enhance care. Diagnostic delays were common and radiological severity worsened with increasing time to diagnosis. There was unexplained variation in treatment, some of which exposes children to significant risks that should be evaluated through randomized controlled trials. Cite this article: Bone Joint J 2022;104-B(4):519–528

Controversy remains as to whether the contralateral hip should be fixed in patients presenting with unilateral slipped capital femoral epiphysis (SCFE). This study compares the outcomes of those patients who had prophylactic fixation with those who did not. We identified 90 consecutive patients with a mean age of 12.3 years presenting to the study centre with SCFE from a prospective operative database. The patient's notes and radiographs were retrospectively analysed for post-operative complications, re-presentation with a contralateral slip, and the presence of a cam lesion. The mean length of follow-up was 8 years (range 3 to 13). Fifty patients (56%) underwent unilateral fixation and 40 patients underwent bilateral fixation, of which 4 (4%) patients had simultaneous bilateral SCFE and 36 (40%) had prophylactic fixation of the contralateral hip. Twenty-three patients (46%) that underwent unilateral fixation, went onto have contralateral fixation for a further SCFE. Two patients from this group had symptomatic femoracetabular impingement from cam lesions and one patient required a Southwick osteotomy for a severe slip. Five patients (10%) that had unilateral fixation only demonstrated cam lesions on radiographic analysis, being suggestive of an asymptomatic slip. No post-operative complications were observed for the contralateral hip in patients that had prophylactic screw fixation and no cam lesions were identified on radiographic assessment. This study suggests that the contralateral hip in patients presenting with unilateral SCFE should be routinely offered prophylactic fixation to avoid a further slip, which may be severe, and the morbidity associated with a secondary cam lesion

We present the results of a prospective study about twenty-nine patients (thirty-two hips) with unstable slipped capital femoral epiphysis (SCFE), which were treated by indirect reduction and internal fixation of the epi- and metaphysis with 3–4 Kirschner-wires between 1990 – 1999. Methods: The 29 patients with a mean age of 12,9 years were clinically and radiologically evaluated after a mean follow-up of 3 years applying the score of Heymann and Herndon and by different roentgenological parameters (CCD-angle, femoral head diameter, length of the femoral neck and sphericity of the femoral head). Compared to the uninvolved side in unilateral case, which all had prophylactic pinning, all patients showed overall a good subjective and objective outcome. The average slip angle of all 29 unstable SCFE patients (32 hips) was 31° with 19 (59,4%) mild SCFE (< 30°), 7 (21,9%) moderate forms (30–50°) and 6 (18,8%) severe slips (> 50°). Results: According to the classification of Heyman and Herndon we had 18 excellent (62,1%), 9 good (31,1%), 1 fair (3,4%) and 1 poor (3,4%) results. None of the patients developed chondrolysis, but AVN occurred in one patient with complete and in one patient with partial involvement of the femoral head. The mean CCD-angle at the follow-up after skeletal maturity of the affected side was 133,3° in comparison to 135,9° of the non affected hips, indicating only a slight increase of varus position of the femoral neck of at average 2,6°. The mean length of the femoral neck of the affected hips was 64,5 mm in comparison to 70,8 mm of the not affected hips, thus a average difference of 6,3 mm. The neck/shaft-ratio between the affected and the not affected side was 0,88 (0,78 – 1,0). The mean femoral head diameter of the affected hips was 57,1 mm in comparison to 55,4 mm of the non affected hips. The radius quotient (RQ), measuring the relation of the femoral heads between the affected and the not affected hip was at average 103% (min 100 %, max. 114%). The sphericity according to Mose of the 58 hips (29 patients) treated by pinning with K-wires was normal (< 2mm) in 89,7% (52 hips), mild I°-aspheric (2–3mm) in 3,4% (2 hips), moderate II°-aspheric (3–4mm) in 3,4% (2 hips) and severe III°-aspheric (> 4mm) in 3,4% (2 hips). Conclusion: As a standard in our institution we recommend the simultaneous transfixation of the epi- and metaphysis with Kirschner-wires in patients with unstable SCFE as therapeutic method for the involved as well as prophylactic for the uninvolved femoral epiphysis. Implants should not be placed in the anterosuperior quadrant of the femoral head and correct implant position has to be documented by the withdrawl maneouver using image intensifier during surgery. With this technique the slip could efficiently be stabilized, further slippage or any progression could be prevented and remodeling of the joint led to an optimal sphericity and improved femoral neck length at the end of growth, thus improving hip function. The rate of severe complications like AVN and chondrolysis was low in our prospective series (6,8% respectively 0%) compared to other series with different implants (screws, nails). There were no complications like implant failure or problems with hardware removal

Introduction: Prophylactic pinning of an asymptomatic hip in SCFE is controversial. Bone age has been used as evidence of future contralateral slip risk and used as an indication for such intervention. The efficacy of bone age assessment at predicting contralateral slip was tested in this study. Patients and Methods: 18 Caucasian children prospectively had bone age assessment using wrist and hand x-rays when presenting with a unilateral SCFE. Patients and parents were informed about the chance of con-tralateral slip and risks of prophylactic fixation, and advised to attend hospital immediately on development of symptoms in contralateral hip. After in-situ fixation of the affected side prospective monitoring in outpatient department was performed. Surgical intervention was undertaken if the contralateral hip was symptomatic. Results: Three children (2 boys) went on to develop to a contralateral slip at a mean of 20 months from initial presentation. 6 children (5 boys) were deemed at risk of contralateral slip due to a bone age below 12.5 years for boys and 10.5 for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95). The sensitivity and specificity were 33% and 66% respectively. With positive predictive value of 15% and diagnostic efficiency of 61%. Conclusion: Delayed bone age by itself is not a good predictor of future contralateral slip at initial presentation. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. Prospective long term longitudinal study is required

Introduction: Prophylactic pinning of an asymptomatic hip in SCFE is controversial. Bone age has been used as evidence of future contralateral slip risk and used as an indication for such intervention. The efficacy of bone age assessment at predicting contralateral slip was tested in this study. Patients and Methods: 18 Caucasian children prospectively had bone age assessment using wrist and hand x-rays when presenting with a unilateral SCFE. Patients and parents were informed about the chance of contralateral slip and risks of prophylactic fixation, and advised to attend hospital immediately on development of symptoms in contralateral hip. After in-situ fixation of the affected side prospective monitoring in outpatient department was performed. Surgical intervention was undertaken if the contralateral hip was symptomatic. Results: Three children (2 boys) went on to develop to a contralateral slip at a mean of 20 months from initial presentation. 6 children (5 boys) were deemed at risk of contralateral slip due to a bone age below 12.5 years for boys and 10.5 for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95). Conclusion: Delayed bone age by itself is not a good predictor of future contralateral slip at initial presentation. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. Prospective long term longitudinal study is required

Introduction: Prophylactic pinning of an asymptomatic hip in SCFE is controversial. Bone age has been used as evidence of future contralateral slip risk and used as an indication for such intervention. The efficacy of bone age assessment at predicting contralateral slip was tested in this study. Patients and Methods: 18 Caucasian children prospectively had bone age assessment using wrist and hand x-rays when presenting with a unilateral SCFE. Patients and parents were informed about the chance of con-tralateral slip and risks of prophylactic fixation, and advised to attend hospital immediately on development of symptoms in contralateral hip. After in-situ fixation of the affected side prospective monitoring in outpatient department was performed. Surgical intervention was undertaken if the contralateral hip was symptomatic. Results: Three children (2 boys) went on to develop to a contralateral slip at a mean of 20 months from initial presentation. 6 children (5 boys) were deemed at risk of contralateral slip due to a bone age below 12.5 years for boys and 10.5 for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95). The sensitivity and specificity were 33% and 66% respectively. With positive predictive value of 15% and diagnostic efficiency of 61%. Conclusion: Delayed bone age by itself is not a good predictor of future contralateral slip at initial presentation. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. Prospective long term longitudinal study is required

Methods. A retrospective review of 80 patients with unilateral slipped capital femoral epiphysis from 1998–2012 was undertaken to determine the outcome of the unaffected hip. All patients were treated with either prophylactic single Richards screw fixation or observation of the uninvolved hip and were followed up for at least 12 months. The unaffected hip of 44 patients (mean age 12.6 years, range 9–17) had simultaneous prophylactic fixation and 36 patients (mean age 13.4 years, range 9–17.4) were managed with observation. Results. Sequential slip of the unaffected hip was noted in 10 patients (28 per cent) in the observation group and only in 1 patient (2 per cent) in the group managed with prophylactic fixation. A Fisher's exact test showed significantly high incidence of sequential slip in unaffected hips when managed with regular observation (p-value 0.002). Only 3 cases had symptomatic hardware on the unaffected side after prophylactic fixation with one requiring revision of the metal work; one had superficial wound infection treated with antibiotics. No cases had AVN or chondrolysis. Conclusion. Simultaneous prophylactic fixation of the unaffected hip significantly reduces the incidence of sequential slip in unilateral SCFE with minimal complications. Level of evidence. III

Unrecognized pin penetrance in the treatment of SCFE by percutaneous pinning has been shown to be under-reported with serious long-term sequelae. The purpose of this study was to use post-operative CT to determine the true position of the screw tip when compared to intra-operative x-rays. Twenty-four patients were offered post operative CT scans in the acute and clinic setting. Intra-operative plain films (AP and lateral) were compared to post operative CT scans (coronal and axial) to determine. the distance of the screw tip from the particular surface of the hip joint,. the number of screw threads across the physis and. the three dimensional placement of the screw tip in the femoral head relative to the physis. The positions of a total of 38 screws were measured. Plain x-rays where shown to consistently underestimate the distance to the articular surface. There were significant differences in the distance to the articular surface in the AP (5.5 mm) vs. coronal (3.4 mm) and lateral (4.7 mm) and vs. axial CT (4.1 mm) planes (p < 0.01). The average number of screw threads across the articular surface on the lateral x-ray was 6.7 vs. 8.1 in the coronal CT (p< 0.05). Four of the screws were shown to penetrate the joint surface in CT not shown on plain film. This study has found that CT scans show screws are closer to the joint surface in the axial and coronal plane on CT when compared to plain x-ray in the AP and lateral plane. CT scans also show that there are more screw threads across the epiphysis than shown on plain x-ray. Placement of the screw within specific quadrants of the femoral head was found to be similar on CT and x-ray. CT scans identified pin penetrance not seen on intra-operative images

Anatomic reduction (subcapital re-alignment osteotomy) via surgical hip dislocation – increasingly popular. While the reported AVN rates are very low, experiences seem to differ greatly between centres. We present our early experience with the first 29 primary cases and a modified fixation technique. We modified the fixation from threaded Steinman pins to cannulated 6.5mm fully-threaded screws: retrograde guidewire placement before reduction of the head ensured an even spread in the femoral neck and head. The mean PSA (posterior slip angle) at presentation (between 12/2008 and 01/2011) was overall 68° (45–90°). 59% (17/29) were stable slips (mean PSA 68°), and 41% (12/29) were unstable slips unable to mobilise (mean PSA 67°). The vascularity of the femoral head was assessed postoperatively with a bone scan including tomography. The slip angle was corrected to a mean PSA of 5.8° (7° anteversion to 25° PSA). We encountered no complications related to our modified fixation technique. All cases with a well vascularised femoral head on the post-operative bone scan (15/17 stable slips and 8/12 unstable slips) healed with excellent short term results. Both stable slips with decreased vascularity on bone scan (2/17, 12%) had been longstanding severe slips with retrospectively suspected partial closure of the physis, which has been described as a factor for increased risk of avascular necrosis (AVN). One of these cases was complicated by a posterior redislocation due to acetabular deficiency. In the unstable group, 4/12 cases (33%) had avascular heads intra-operatively and cold postoperative bone scans, 3 have progressed to AVN and collapse. Anatomic reduction while sparing the blood supply of the femoral head is a promising concept with excellent short term results in most stable and many unstable SCFE cases. Extra vigilance for closed/closing physes in longstanding severe cases seems advisable. Regardless of treatment, some unstable cases inevitably go on to AVN

In situ fixation of mild slips of the slipped capital femoral epiphysis (SCFE) is a safe and reliable method of treatment. Hardware failure and fractures are reported at the time of pin retrieval. Difficulty in removing these pins is well reported. Major problems can be expected when arthroplasty is necessary years later, if the pins are still inside the proximal femur. Hence we have come up with a novel technique to remove these pins during Primary Total hip arthroplasty.

The hip is exposed through posterior approach, dislocated and the neck is then cut at the usual site. It is then segmented in both sagittal and coronal planes into approximately eight to ten pieces and removed piecemeal. The pins are thus exposed, cleared of any bony debris and hammered retrograde.

By using our simple and novel technique to remove these pins we feel it avoids unnecessary trauma to the outer cortex of femur and also reduces the operating time significantly.

Introduction and Objective. Slipped Capital Femoral Epiphysis (SCFE) is one of the most common hip disorders in children and is characterized by a proximal femoral deformity, resulting in early osteoarthritis. Several studies have suggested that SCFE patients after in situ fixation show an altered gait pattern. Early identification of gait alterations might lead to earlier intervention programs to prevent osteoarthritis. The aim of this study is to analyse gait alterations in SCFE patients after in situ fixation compared to typically developed children, using the Computer Assisted Rehabilitation Environment (CAREN) system. Materials and Methods. This is a cross-sectional, multi-center case-control study in the Netherlands. Eight SCFE patients and eight age- and sex-matched typically developed were included from two hospitals. Primary outcomes were kinematic parameters (absolute joint angles), studied with gait analysis using statistical parametric mapping (SPM). Secondary outcomes were spatiotemporal parameters, the Notzli alpha angle, muscle activation patterns (EMG), and clinical questionnaires (VAS, Borg CR10, SF-36, and HOOS), analyzed using non-parametric statistical methods. Results. Patients (mean BMI=28±9 kg/m. 2. ) showed altered gait patterns, with significantly increased external hip rotation and decreased downward pelvic obliquity during the pre-swing phase of the gait cycle compared to typically developed (mean BMI=22±3 kg/m. 2. ). Walking speed, cadence, % stance time, and step length were reduced in SCFE patients. Coefficient of variances of cadence, stance time, and step length were increased. Patients had a mean alpha angle of 64, SD=7.9. Clinical questionnaires showed that general health (SF-36) was 80±25, energy/fatigue (SF-36) was 67±15, pain (VAS) was 0±1.5, and total HOOS score was 85±18. Conclusions. SCFE patients after in situ fixation appear to have developed a compensation mechanism, showing slight alterations in gait parameters, good general health, little functional limitations of the hip, and no self-reported pain. Cam deformities, altered joint loading, and this compensation mechanism might influence long-term early osteoarthritis. BMI reduction should be implemented in care plans, as obesity might also play a role in unfavorable long-term outcomes

Slipped capital femoral epiphysis (SCFE) is traditionally treated with in situ fixation using a threaded screw, leading to physeal arrest while stabilizing the femoral head. Recently, there has been interest in alternative methods of fixation for SCFE, aiming to allow growth and remodelling of the femoral neck postoperatively. One such option is the Free Gliding SCFE Screw (Pega Medical), which employs a telescopic design intended to avoid physeal compression. The objective of this study is to evaluate radiographic changes of the proximal femur following in situ fixation using the Free Gliding SCFE Screw. This study retrospectively evaluated 28 hips in 14 consecutive patients who underwent in situ hip fixation using the Free Gliding SCFE Screw between 2014 and 2018. Initial postoperative radiographs were compared to last available follow-up imaging. Radiographic assessment included screw length, articulotrochanteric distance (ATD), posterior sloping angle (PSA), alpha angle, head-neck offset (HNO) and head-shaft angle (HSA). Of the 28 hips reviewed, 17 were treated for SCFE and an additional 11 treated prophylactically. Average age at surgery was 11.7 years, with an average follow-up of 1.44 years. Screw length increased by 2.3 mm (p < 0.001). ATD decreased from 25.4 to 22.2 mm (p < 0.001). Alpha angle decreased from 68.7 to 59.8 degrees (p = 0.004). There was a trend towards an increase in HNO (p = 0.07). There was no significant change in PSA or HAS. There were three complications (two patients with retained broken guide wires, and one patient requiring screw removal for hip pain). With use of the Free Gliding SCFE Screw, there was evidence of screw expansion and femoral neck remodelling with short-term follow-up. More research is required to determine the long-term impact of these changes on hip function, and to aid in patient selection for this technology

The risk of AVN is high in Unstable Slipped Capital Femoral Epiphysis (SCFE) and the optimal surgical treatment remains controversial. Our AVN rates in severe, unstable SCFE remained unchanged following the introduction of the Modified Dunn Procedure (MDP) and as a result, our practice evolved towards performing an Anterior Open Reduction and Decompression (AOR) in an attempt to potentially reduce the “second hit” phenomenon that may contribute. The aim of this study was to determine the early surgical outcomes in Unstable SCFE following AOR compared to the MDP. All moderate to severe, Loder unstable SCFEs between 2008 and 2022 undergoing either an AOR or MDP were included. AVN was defined as a non-viable post-operative SPECT-CT scan. Eighteen patients who underwent AOR and 100 who underwent MPD were included. There was no significant difference in severity (mean PSA 64 vs 66 degrees, p = 0.641), or delay to surgery (p = 0.973) between each group. There was no significant difference in the AVN rate at 27.8% compared to 24% in the AOR and MDP groups respectively (p = 0.732). The mean operative time in the AOR group was 24 minutes less, however this was not statistically significant (p = 0.084). The post-reduction PSA was 26 degrees (range, 13–39) in the AOR group and 9 degrees (range, -7 to 29) in the MDP group (p<0.001). Intra-operative femoral head monitoring had a lower positive predictive value in the AOR group (71% compared to 90%). Preliminary results suggest the AVN rate is not significantly different following AOR. There is less of an associated learning curve with the AOR, but as anticipated, a less anatomical reduction was achieved in this group. We still feel that there is a role for the MDP in unstable slips with a larger remodelling component

Despite recent advances in the management of slipped capital femoral epiphysis (SCFE), controversy remains about the treatment of choice for unstable slips. Surgical dislocation and open reduction has the advantage of identifying and preserving the blood supply of femoral head thereby potentially reducing the risk of avascular necrosis, (AVN). There is large variation in the literature from several small series about reported AVN rates ranging from two to 66% for unstable SCFE treated with surgical dislocation. The aim of our study was to analyze our experience with acute open reduction and internal fixation of unstable acute and unstable acute on chronic slips using the technique of surgical dislocation described by Professor Reinhold Ganz. A retrospective review of 11 patients (12 hips) treated by surgical dislocation, reduction and pinning as the primary procedure for unstable acute and unstable acute on chronic SCFE in a tertiary referral children's hospital was undertaken. This represents the entire series treated in this manner from September 2007 to January 2018. These procedures were performed by a team of Orthopaedic surgeons with significant experience performing surgical dislocation of the hip including patients with chronic SCFE, Perthes' disease, impingement and acetabular fractures. Demographic data, intraoperative records, postoperative notes and radiographs including details of subsequent surgery were reviewed. There were seven boys and four girls with mean age of 13.4 years, range 11 to 15 years at the time of surgical dislocation. Out of 12 hips, two had acute unstable slip while the remaining 10 had acute on chronic unstable slip. Six patients had good or excellent results. The remaining six patients developed AVN of which three patients had total hip replacement at six months, 17 months and 18 months following primary procedure. Seven patients required more than one operation. Three patients lost their correction and required re fixation despite surgical dislocation, reduction and fixation being their primary procedure. This series demonstrates a high percentage of AVN (50%) in severe unstable SCFE treated with surgical dislocation despite careful attention to retinacular flap development and intra operative doppler studies. This is in direct contrast to our experience with subcapital reorientation with surgical dislocation in stable slips where excellent results were achieved with a low rate of AVN. Pre-operative imaging with MRI and perfusion studies may identify where ischemia has occurred and might influence operative treatment. Based on our results, we do not recommend routine use of surgical dislocation in unstable SCFE. This technique requires further scrutiny to define the operative indications in unstable SCFE

Slipped capital femoral epiphysis (SCFE) is associated with a spectrum of proximal femoral deformity and femoroacetabular impingement (FAI). Little attention has been given, however, to the possible effect of SCFE on remaining hip growth. Our observation that some acetabula in hips with SCFE have various dysmorphology led us to evaluate the growth of the hip in our patients with SCFE. We performed an IRB-approved retrospective study of our intramural SCFE database which identified 108 hips with unilateral SCFE, at least 2 years of radiographic followup, and closure of triradiate cartilage, greater trochanter and proximal femoral physis. The contralateral non-SCFE hip was used as control. Average age at presentation was 12.3 y. 49 patients were male, 59 female. Statistically significant differences were noted between SCFE and control hip both at both presentation and last followup(FU): Mean LCEA lower in SCFE hip at presentation by 0.97 degree; increasing to 4.36 degrees at last FU(p<0.0001). No difference noted in mean Tonnis roof angle at presentation, but at last FU SCFE hips had mean roof angle difference of 3.2 degrees higher than control(p<.0001). In some of our SCFE patients, acetabular deformity has impacted treatment. Ongoing studies may clarify risk factors for the development of problematic acetabular deformity associated with SCFE and perhaps allow prevention of secondary acetabular deformity

Background. Slipped capital femoral epiphysis (SCFE) creates a complex deformity of the hip that can result in cam type of femoroacetabular impingement (FAI), which may in turn lead to the early development of osteoarthritis of the hip. The purpose of this study was to evaluate the existing literature reporting on the efficacy of hip arthroscopic treatment of patients with FAI secondary to SCFE. Methods. A systematic computer search was conducted based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using Embase, PubMed (Medline), and Cochrane Library up to November 2019. Data such as patient demographics, surgical outcomes and complications that described arthroscopic surgery following FAI secondary to SCFE were retrieved from eligible studies. Two authors independently reviewed study inclusion and data extraction with independent verification. Results. Following filtration, seven studies were included in this review comprising 96 patients (100 hips). The mean age was 14.9 years (SD, 2.7), and 54.2% of the cases were male. Eighty seven percent patients had undergone previous procedures at the first diagnosis of SCFE. Slip severity at the time of performing hip arthroscopy was mild for 54%, moderate for 31% and severe deformity for 15%. The mean alpha angle corrections was 32.0° (SD, 6.0°), and the mean improvement of internal rotation angle at 90° flexion was 23.6° (sd, 9.5°). ModifiedHarris Hip Scores (mHHS) was most reported (n = 3 studies; 38 hips) of the clinical outcomes, and the mean improvement of mHHS was 22.0 (sd, 3.6). Complication rates were 10%, and revision rate was 6.0%. Conclusion. Patients with FAI secondary to SCFE undergoing arthroscopic treatment demonstrate improved improvement in clinical outcome, rotation of the hip and correction of the alpha angle. It remains to be seen whether this eventually leads to prevention of OA and avoiding arthroplasty in this group of patients

Prophylactic fixation of the contralateral hip in cases of unilateral slipped capital femoral epiphysis (SCFE) remains contentious. Our senior author reported a 10 year series in 2006 that identified a rate of subsequent contralateral slip of 25percnt; when prophylactic fixation was not performed. This led to a change in local practice and employment of prophylactic fixation as standard. We report the 10 year outcomes following this change in practice. A prospective study of all patients who presented with diagnosis of SCFE between 2004 and 2014 in our region. Intra-operative complication and post-operative complication were the primary outcomes. 31 patients presented during the study period: 16 male patients and 15 female patients. The mean age was 12.16 (8–16, SD 2.07). 25 patients had stable SCFE and 5 had unstable SCFE. Stability was uncertain in 1 patient. 25 patients had unilateral SCFE and 6 had bilateral SCFE. 24 patients who had unilateral SUFE had contralateral pinning performed. 1 unilateral SCFE did not have contralateral pinning performed as there was partial fusion of physis on contralateral side. In the hips fixed prophylactically there was 1 cases of transient intraoperative screw penetration into the joint and 1 case of minor wound dehiscence. There were no cases or chondrolysis or AVN. There were no further contralateral slips. This change in practice has been adopted with minimal complication. The fixation of the contralateral side is not without risk but by adopting this model the risk of subsequent slip has been reduced from 25percnt; to 0percnt;

INTRODUCTION. Childhood diseases involving the proximal femoral epiphysis often cause abnormalities that can lead to end-stage arthritis at a relatively young age and the need for total hip arthroplasty (THA). The young age of these patients makes hip resurfacing arthroplasty (HRA) an alternative and favorable option due to the ability to preserve femoral bone. Patients presenting with end-stage hip arthritis as sequelae of childhood diseases such as Legg-Calves-Perthes (LCP) and slipped capital femoral epiphysis (SCFE) pose altered femoral anatomy, making HRA more technically complicated. LCP patients can result in coxa magna, coxa plana and coxa breva causing altered femoral head-to-neck ratio. There can also be acetabular dysplasia along with the proximal femoral abnormalities. SCFE patients have altered femoral head alignment. In particular, the femoral head is rotated medially and posteriorly, reducing the anterior and lateral offset. Additionally, many of these patients have retained hardware, making resurfacing more complicated. We report findings of a cohort of patients, with history of either LCP or SCPE who underwent HRA to treat end-stage arthritis. METHODS. Data was retrospectively collected for patients who had HRA for hip arthritis as a result of either LCP (n=67) or SCFE (n=21) between 2004 and 2014 performed by two surgeons. Demographic information, clinical examination and improvement was collected pre and postoperatively. Improvement was determined using Harris Hip Scores (HHS) and UCLA activity scores. Anteroposterior radiographs were measured pre and postoperatively to determine leg length discrepancy. Radiographs were inspected postoperatively for radiolucent lines, implant loosening and osteolysis. Kaplan-Meier survivorship for freedom from reoperation for any reason was calculated. Paired student t-tests were used to compare groups. RESULTS. The average age at the time of surgery was 44 years (11.8–68), with an average follow-up of 3.7 years (.22–11.2). Retained hardware was present in a total of 5 patients, 1 LCP and 4 SCFE. Preoperative HHS was 58.3 (33–83), which increased significantly to 94.9 (55–100) at the most recent postoperative timepoint (p<.0001). The most recent UCLA activity score was 7 (1–10). Average leg length discrepancy preoperatively was 7.5mm (0–20), which significantly improved to 0.6mm (0–7.5) postoperatively (p<.0001). At most recent follow-up, metal ion testing revealed median chromium level of 2.3 parts per billion (ppb, 1–7.7) and median cobalt level of 1.5 (0–9.2). There were three failures in the group with 1 LCP due to instability at 2.7 years, and 2 SCFE due to femoral neck fracture at 1 month in one and clinical failure due to unexplained pain at 5.5 years in one. Revision surgery was done in 2 patients, 1 LCP and 1 SCFE. Radiographic examination of all non-failure HRA patients revealed implants to be in good alignment with no indication of implant loosening at the most recent postoperative timepoint. Kaplan-Meier survivorship for freedom from revision was 96.2 at 5 years. CONCLUSION. The findings demonstrated increase in functional outcomes in patients who underwent HRA for osteoarthritis associated with LCP and SCFE. There was no increase in complications including femoral neck fracture or implant loosening despite technical challenges of the procedure

Aims. Slipped capital femoral epiphysis (SCFE) is one of the most common hip diseases of adolescence that can cause marked disability, yet there is little robust evidence to guide treatment. Fundamental aspects of the disease, such as frequency, are unknown and consequently the desire of clinicians to undertake robust intervention studies is somewhat prohibited by a lack of fundamental knowledge. Methods. The study is an anonymized nationwide comprehensive cohort study with nested consented within the mechanism of the British Orthopaedic Surgery Surveillance (BOSS) Study. All relevant hospitals treating SCFE in England, Scotland, and Wales will contribute anonymized case details. Potential missing cases will be cross-checked against two independent external sources of data (the national administrative data and independent trainee data). Patients will be invited to enrich the data collected by supplementing anonymized case data with patient-reported outcome measures. In line with recommendations of the IDEAL Collaboration, the study will primarily seek to determine incidence, describe case mix and variations in surgical interventions, and explore the relationships between baseline factors (patients and types of interventions) and two-year outcomes. Discussion. This is the first disease to be investigated using the BOSS Study infrastructure. It provides a robust method to determine the disease frequency, and a large unbiased sample of cases from which treatment strategies can be investigated. It may form the basis for definitive robust intervention studies or, where these are demonstrated not to be feasible, this may be the most robust cohort study

Purpose. Slipped capital femoral epiphysis (SCFE) is the most common hip disorder in children 9–15 years old. The epidemiology for SCFE in the total population of Sweden has not yet been described. Methods. In a prospective cohort study, we analysed pre- and postoperative radiographs and medical records for all children treated for SCFE in Sweden 2007–2013, and noted demographic data, severity of slip, and surgical procedures performed. Results. We identified 379 Swedish children with primary SCFE 2007–2013; 162 girls, median age 12 (7–15) years, and 217 boys, median age 13 (4–17) years. The cumulative incidence was 45.8/100 000 for girls and 58.2/100 000 for boys. As an initial symptom, 66% of the children had hip/groin pain and 12% knee pain. At first presentation, 7% of the children had bilateral SCFE. Prophylactic fixation was performed in 43% . Of the remaining children, 21% later developed a contralateral slip. Fixation with implants permitting further growth of the femoral neck was used in 90% of the children. Femoral neck osteotomy was performed for 11 hips. Of 34 treating hospitals, only three treated > 3 children with SCFE annually. Conclusions. The cumulative incidence 2007–2013 in the total population in Sweden showed a mild increase for girls. The male-to-female ratio was lower than previously described for Sweden. Prophylactic fixation was performed in 43% of the children. Fixation with an implant that allows further growth was used for 90% of the children. Most hospitals in Sweden treat < 2 children annually