Fixation Of Slipped Capital Femoral Epiphysis Research Articles

Limited angular remodelling after in-situ fixation for slipped capital femoral epiphysis

BackgroundIn Sweden, most children with slipped capital femoral epiphysis (SCFE) are operated on with a single smooth pin or a short-threaded screw, allowing further growth of the femoral neck. Using the Swedish Pediatric Orthopaedic Quality registry, SPOQ, we investigated whether angular remodelling occurs adjacent to the proximal femoral epiphysis after fixation of SCFE using implants, allowing continued growth of the femoral neck.MethodsDuring 2008–2010 a total national population of 155 children were reported to the SPOQ registry. Following our strict inclusion criteria, radiographs of 51 hips were further assessed. The lateral Head Shaft Angle (HSA), the Nötzli 3-point α-angle, the anatomic α-angle, and the Anterior Offset Ratio (AOR) on the first postoperative radiographs and at follow-up were measured to describe the occurrence of remodelling. Slip severity was categorised as mild, moderate or severe according to postoperative HSA.ResultsMean and SD values for the change in HSA were 3,7° (5,0°), for 3-point α-angle 6,8° (8,9°), and anatomic α-angle 13,0° (16,3°). The overall increase in AOR was 0,038 (0.069). There were no significant differences between the slip severity groups.ConclusionsWe found limited angular remodelling after in situ fixation with smooth pins or short threaded screws for SCFE. The angular remodelling and the reduction of the CAM deformity was less than previously described after fixation of SCFE with similar implants. Results about the same magnitude with non-growth sparing techniques suggest that factors other than longitudinal growth of the femoral neck are important for angular remodelling.

The Effect of the Type of Screw Fixation Used in the Treatment of Slipped Capital Femoral Epiphysis.

Background Slipped capital femoral epiphysis (SCFE) remains among the most common hip disorders in the adolescent population. The management of SCFE remains controversial; however, the aim of fixation is to stabilize the physis and prevent further slippage. In situ fixation remains the gold standard; however, in the young population, it can lead to reduced femoral neck growth and complications such as leg length discrepancies. The ideal form of in situ fixation for mild to moderate SCFE would stabilize the slip and allow continued proximal femoral growth. This study aimed to determine if partially threaded screws allowed more neck growth than fully threaded screws. Methods A retrospective review of the radiographs of all patients undergoing in situ fixation for SCFE using partially threaded and fully threaded screws. Measurements included neck length, neck-to-screw ratio, neck shaft angle, neck width, and articular-trochanteric distance. Parameters were compared over a two-year period to determine whether there was any difference in proximal femoral growth between the two types of screws. Results Fully threaded screw neck length increased by 5 mm versus 5 mm for proximally threaded screws (P ≤ 0.001). No significant difference was observed between the two groups with respect to neck width, neck shaft angle, and articular-trochanteric distance. Conclusions No difference was observed in proximal femoral growth. Regardless of which type of fixation is used, neck length continues to increase by approximately 3 mm per year.

Hardware Impingement Is Associated With Shorter Screw Length in Patients Treated With In Situ Screw Fixation for Slipped Capital Femoral Epiphysis: An In Vivo Arthroscopic Evaluation

PurposeTo determine the incidence of screw impingement on dynamic exam during hip arthroscopy in patients undergoing treatment for femoroacetabular impingement after previous slipped capital femoral epiphysis fixation and to evaluate screw characteristics with hardware impingement.MethodsA retrospective review from 2008 to 2020 was performed of slipped capital femoral epiphysis (SCFE) patients that underwent arthroscopy for symptoms of hip impingement. Patients underwent a dynamic exam under direct arthroscopic visualization to assess for sources of impingement, including bony anatomy and fixation hardware. Slip angle was calculated on lateral radiographs prior to arthroscopy, and screw length was noted in the initial operative reports at treatment of SCFE and reported in millimeters. Normality of data was assessed using Shapiro-Wilk tests, with statistical analysis performed using independent sample t-tests, Mann-Whitney U-nonparametric tests, and multivariable logistic regression. An alpha level of <0.05 was used to indicate statistical significance.ResultsThirty-nine hips were included, with 13 (33.3%) having screw impingement on dynamic exam. Slip angle was found to be increased in the screw impingement group (42.4° vs 35.5°; P = .11). Screw length was noted to be significantly shorter in the screw impingement group (53.1 vs 61.6 mm; P = .021). The presence of screw impingement was found to be associated with shorter screw length (β = −0.172, R2 = 0.329; P = .036).ConclusionsShorter screws (55 mm or less) are at greater risk of causing hardware hip impingement after in situ SCFE fixation. When considering hip arthroscopy for the treatment of femoroacetabular impingement in patients with a previous SCFE, hardware impingement and subsequent hardware removal should be considered in hips with shorter screws and in hips that show objective hardware impingement on dynamic exam.Level of EvidenceLevel IV, therapeutic case series.

Integrating Simulation for Developing Slipped Capital Femoral Epiphysis Fixation Skills into an Orthopaedic Surgery Residency Program

Slipped capital femoral epiphysis (SCFE) in pediatric and adolescent patients is a common hip injury treated at tertiary care centers and children’s hospitals. The relatively uncommon nature of SCFE in association with the reliable and reproducible resulting deformity make for the ideal opportunity to supplement orthopedic resident and/or fellow operative experience with simulation training. This approach will allow trainees to develop expert performance and ensure that a benchmark proficiency skill level is attained.

Screw Thread Configuration Has No Effect on Outcomes of In Situ Fixation for Stable Slipped Capital Femoral Epiphysis.

No consensus exists regarding the optimal surgical management of slipped capital femoral epiphysis (SCFE). Treatment goals include avoiding slip progression and sequelae such as avascular necrosis (AVN). Factors associated with surgical implants merit further research. This study investigates the effect of screw thread configuration and the number of screws on surgical outcomes. A total of 152 patients undergoing cannulated, stainless steel, in situ screw fixation of SCFE between January 2005 and April 2018 were included. Procedure laterality, screw number and thread configuration (partially threaded/fully threaded), bilateral diagnosis, Loder classification, final follow-up, patient demographics, and endocrinopathy history were analyzed. Primary outcomes were return to the operating room (ROR), AVN, hardware failure/removal, and femoroacetabular impingement (FAI). Most patients received a single (86.2%), partially threaded (81.6%) screw; most were unilateral (67.8%) and stable (79.6%). Mean follow-up was 2.0±2.7 years, with a 15.8% rate of ROR, 5.3% exhibiting AVN, 6.6% exhibiting FAI, and 9.2% experiencing hardware failure/removal. Number of screws was the sole predictor of ROR [odds ratio (OR)=3.35, 95% confidence interval (CI): 1.18-9.49]. Unstable SCFE increased the odds of AVN (OR=38.44; 95% CI: 4.35-339.50) as did older age (OR=1.43, 95% CI: 1.01-2.03). Female sex increased risk for FAI (OR=4.87, 95% CI: 1.20-19.70), and bilateral SCFE elevated risk for hardware failure/removal versus unilateral SCFE (OR=4.41, 95% CI: 1.39-14.00). Screw thread configuration had no significant effect on any outcome (for each, P ≥0.159). Rates of ROR, AVN, FAI, and hardware failure/removal did not differ between patients treated with partially threaded or fully threaded screws. The use of 2 screws was associated with an increased likelihood of ROR. These findings suggest that screw thread configuration has no impact on complication rates, whereas screw number may be an important consideration in SCFE fixation. Level III-retrospective cohort study.

Development and Validation of SCFE Percutaneous Pinning Surgical Simulation.

In situ screw fixation with a single percutaneously placed femoral screw remains widely accepted for femoral head fixation in adolescent patients with slipped capital femoral epiphysis (SCFE). Given the potential risks involved with this procedure, a simulation whereby surgical skills could be refined before entering the operating room may be of benefit to orthopaedic trainees. We developed a synthetic model for the simulated treatment of SCFE. Five orthopaedic attendings and twenty trainees were recorded performing an in situ percutaneous fixation on the SCFE model. Time, radiation exposure, and final anteroposterior and lateral radiographs of the SCFE model were recorded. After completion, the attendings and trainees answered a Likert-based questionnaire regarding the realism and utility of the simulation, respectively. Two blinded orthopaedic surgeons rated each participant's skill level based on previously described assessment tools, including a Global Rating Scale (GRS) of technical proficiency and radiographic grading index for screw placement. Performance metrics and survey responses were evaluated for construct validity, face validity, and interrater reliability. The attendings demonstrated superior technical proficiency compared with trainees in terms of higher GRS scores (27.9±1.9 vs. 14.7±5.0, P<0.001) and better radiographic grading of screw placement on lateral views (P=0.019). Similarly, compared with the trainees, the orthopaedic attendings demonstrated shorter operative times (11.0±4.1 vs. 14.7±6.2 min, P=0.035) and less radiation exposure (3.7±1.7 vs. 9.5±5.7 mGy, P=0.037). The interrater reliability was excellent for both the GRS scoring (intraclass correlation coefficient=0.973) and radiographic grading (weighted κ=1.000). The attendings and trainees rated the realism and teaching utility of the simulation as "very good," respectively. Our surgical simulation for in situ percutaneous fixation of SCFE represents a valid and reliable measure of technical competency and demonstrates much promise for potential use as a formative educational tool for orthopaedic residency programs. Level II.

Factors Affecting Slip Progression After In Situ Screw Fixation of Stable Slipped Capital Femoral Epiphysis.

Slip progression after in situ fixation of slipped capital femoral epiphysis (SCFE) has been reported as occurring in up to 20% of patients. We review SCFE treated with in situ single screw fixation performed at 2 hospitals over a 15-year period to determine the factors associated with slip progression. This case-control study reviews SCFE treated with in situ single cannulated screw fixation with minimum follow up of 1 year and full closure of the affected physis. Slip progression (failure) was defined as worsening of the Southwick slip angle of 10 or more degrees or revision surgery for symptomatic slip progression. Univariate and multivariate analyses were performed comparing success and failure groups for patient characteristics, screw type and position, and radiographic measurements. Ninety three patients with 108 slips met all criteria, with 15 hips (14%) classified as having slip progression (failure). All failures had 3 threads or fewer across the physis. Five hips had 2 threads across the physis, and 4 of the 5 were classified as failures. Lower modified Oxford bone scores were found in the failure group, though the difference was small (0.9, P=0.013). Failure was also associated with partially threaded screws (P=0.001). Failed hips were associated with lower initial Southwick angles (32.8 degrees) than successful hips (40.4 degrees) (P=0.047). In the stepwise model for multivariate regression, 4 factors were identified as significant, with lower initial number of threads (P<0.0001), mild initial Southwick category (P=0.0050), male sex (P=0.0061), and partially threaded screw type (P=0.0116) predicting failure. This study is the largest to date evaluating risk factors for slip progression after SCFE fixation, and the first to consider revision surgery for symptomatic slip progression. For stable SCFE, we demonstrate that 4 threads across the physis with a fully threaded screw of 6.5 mm diameter or greater was sufficient to avoid slip progression. We provide a risk stratification for progression of slip showing that in some cases 3 threads across the physis may be sufficient. Level III-case-control study.

A Simple Modified Technique for In-Situ Screw Fixation in Slipped Capital Femoral Epiphysis.

In-situ pinning has a definite role in the management of slipped capital femoral epiphysis (SCFE). We describe a modified technique for in-situ screw fixation on a regular radiolucent operating table which avoids certain complications innate with the existing techniques. Sixty consecutive hips which underwent either in-situ fixation for SCFE (28 hips) or prophylactic fixation of the contralateral hip (32 hips) by the modified technique were analysed. The femoral head was divided into three zones (A-central, B-middle, C-peripheral) of equal circles. The zone of the screw was noted in both AP and lateral views. The angle between the physeal line and the screw in AP(SAP) and lateral (Slat) view, and the distance from screw tip to articular surface in both views were measured. In AP view, 55/60 (91.6%) screws were in zone-A, and five were in zone-B. In the lateral view, 56/60 (93.3%) screws were in zone-A, and four were in zone-B. There was no screw placed in zone-C in either of the views. The average deviation was < 15° in AP view and < 7° in lateral view from the ideal placement. The mean distance from the screw tip to the articular margin in AP was 5.15mm and that in lateral was 6.15mm. The interobserver agreement rate was found to be 0.8. No patient had intraoperative breakage of a drill bit or joint penetration, avascular necrosis, chondrolysis or screw-related complications at a minimum follow-up of one year. In-situ pinning on the radiolucent table is safe and has distinct advantages. The modified technique of in-situ screw fixation adds to the safety and accuracy of the procedure. Level IV.

Hip arthroscopy following slipped capital femoral epiphysis fixation: chondral damage and labral tears findings.

PurposeThis study investigated the association between chondrolabral damage and time to arthroscopic surgery for slipped capital femoral epiphysis (SCFE).MethodsThis was a descriptive retrospective study that enrolled patients with SCFE who underwent hip arthroscopy for femoral osteochondroplasty after SCFE fixation. SCFE type, time from SCFE symptom onset or slip fixation surgery to hip arthroscopy and intraarticular arthroscopic findings were recorded. Acetabular chondrolabral damage was evaluated according to the Konan and Outerbridge classification systems. Nested analysis of variance and the chi-squared test were used for statistical analyses.ResultsWe analyzed 22 cases of SCFE in 17 patients (five bilateral). The mean age at the time of hip arthroscopy was 13.6 years-old (8–20), and mean time from SCFE fixation to arthroscopy was 25.1 months (3 weeks to 8 years). Labral frying was present in 20 cases, labral tears in 16 and acetabular chondral damage in 17. The most frequent lesion was type 3 (41%) (Konan classification). Two cases had a grade III and 1 had a grade II acetabular chondral lesion (Outerbridge classification). Positive associations were observed between time from SCFE to hip arthroscopy and hip intraarticular lesions evaluated using Konan (p = 0.004) and Outerbridge (p = 0.000) classification systems. There was no association between SCFE severity (chi-squared = 0.315), stability (chi-squared = 0.558) or temporality (chi-squared = 0.145) type and hip intraarticular lesions.ConclusionA longer time from SCFE symptom onset and fixation to hip arthroscopy is associated with greater acetabular chondrolabral damage.Level of evidenceIV

Proximal Femoral Deformity Following Threaded Prophylactic Fixation for Slipped Capital Femoral Epiphysis: Risk Stratification Using the Modified Oxford Score.

This study assesses the effect of skeletal maturity on the development of iatrogenic proximal femoral deformity following threaded prophylactic screw fixation in patients presenting with unilateral slipped capital femoral epiphysis (SCFE). Children who underwent threaded screw prophylaxis of the uninvolved hip (Group P) and those who were observed with no prophylaxis (Group N) on presentation with unilateral SCFE were compared. Skeletal maturity was assessed with the Modified Oxford Score (MOS). Proximal femoral morphology was characterized by femoral neck length, femoral neck width, neck shaft angle, and trochanteric femoral head overlap percentage (TFHOP). Femoral head deformity at final follow-up was characterized as spherical (Type 1), mildly aspherical (Type 2), or ovoid (Type 3). Analysis of variance and t test were used to compare the groups. Thirty-eight patients in Group P and 17 patients in Group N met inclusion criteria. The average follow-up was 2.6 years. Group P was younger than Group N by an average of 9.6 months (P=0.04), but the MOS for skeletal maturity was not different between groups (P=0.15). Group P had significantly diminished neck length (P=0.008) and significantly increased relative trochanteric overgrowth as evidenced by increased trochanteric femoral head overlap percentage (P<0.001), but there was no difference between groups in neck shaft angle and neck width. No patient in Group N developed femoral head deformity (all Type 1). In Group P, 14 patients (37%) developed Types 2 and 3 deformity. In patients with MOS 16 in Group P, 60% (3/5) developed Type 2 deformity and 40% (2/5) developed Type 3 deformity. In patients with MOS 17 in Group P, 45% (5/11) had Type 2 deformity. Skeletally immature patients with an MOS of 16 and 17 are at high risk for developing the triad of relative trochanteric overgrowth, coxa breva, and femoral head asphericity with prophylactic threaded screw fixation for SCFE. When prophylactic surgery is indicated, consideration should be given to growth friendly fixation strategies to avoid iatrogenic proximal femoral deformity. Level III-therapeutic retrospective comparative study.

The Oxford Spherical Mill for Metaphyseal Debridement in Open Epiphyseal Reduction and Internal Fixation for Slipped Capital Femoral Epiphysis

Slipped capital femoral epiphysis (SCFE) is an adolescent hip disorder characterized by displacement of the proximal femoral epiphysis relative to the metaphysis. The aim of treatment is to stabilize the proximal epiphysis, avoid further displacement and prevent femoral head osteonecrosis. Open reduction and internal fixation is often required to treat chronic and severe SCFE, typically using a Modified Dunn procedure. This allows anterior access to the proximal femur, epiphyseal mobilization and metaphyseal debridement of cervical callus. Debriding the cervical callus concentrically to allow accurate relocation of the epiphysis on the metaphysis can be challenging. This article describes the benefits of using the Oxford Spherical Mill from a partial knee replacement system to assist with metaphyseal debridement during open epiphyseal reduction and internal fixation for SCFE.

The reliability of radiostereometric analysis in determining physeal motion in slipped capital femoral epiphysis in standard uniplanar and low-dose EOS biplanar radiography: a phantom model study.

Physeal closure after slipped capital femoral epiphysis fixation can be difficult to assess on two-dimensional conventional radiographs. Radiostereometric analysis offers improved motion detection over conventional radiography, whereas the EOS biplanar imager provides a means for low radiation weight-bearing images. This phantom study assessed the reliability of measuring motion using radiostereometric analysis in the EOS using a slipped capital femoral epiphysis model. The accuracy and precision were better than 0.09±0.05 mm and 0.20°±0.36° when centered in the imaging space, were within the limits of clinical significance, and were not different from a standard uniplanar radiostereometric system.

Continued Growth of the Femoral Neck Leads to Improved Remodeling After In Situ Fixation of Slipped Capital Femoral Epiphysis.

Globally, the most common method for in situ fixation of slipped capital femoral epiphysis (SCFE) is a threaded screw, which causes physeal arrest. The standard treatment in Sweden is unthreaded fixation using the Hansson hook-pin, which leads to continued growth of the femoral neck. Our purpose was to study remodeling during the remaining growth after fixation with the Hansson hook-pin. We performed a retrospective study of 54 patients with SCFE who were treated with the Hansson hook-pin between 2001 and 2009. The immediate postoperative radiograph and the radiograph taken after physeal closure (mean interval, 34 mo) were analyzed. Three radiographic assessments were used: the head-shaft angle (HSA), the alpha angle (Nötzli), and the displacement from Klein's line. Significant remodeling was detected in all measured parameters. The mean postoperative HSA decreased by 9.0 degrees (P<0.001). The alpha angle improved by a mean of 14.5 degrees (P<0.001). Significant correlations were found between the reduction of the alpha angle and age (P<0.001, R=0.48) and longitudinal growth of the femoral neck (P<0.001, R=0.67). Displacement from Klein's line increased by a mean of 1.6 mm (P=0.006). Unthreaded fixation of SCFE using the Hansson hook-pin leads to substantial remodeling of the femoral neck. The positive correlation observed between the improvement of the alpha angle and femoral neck growth supports the use of a method that allows continuous growth, to reduce the risk of femoroacetabular impingement. Level III-retrospective comparative study.

Continued growth after fixation of slipped capital femoral epiphysis.

PurposeWhen treating slipped capital femoral epiphysis (SCFE), a smooth pin with a hook or a short threaded screw can be used to allow further growth, which could be important to prevent the development of impingement and early arthritis. The purpose of this investigation was to measure growth in three dimensions after fixation of SCFE.MethodsSixteen participants with unilateral SCFE, nine girls and seven boys with a median age of 12.0 years (range 8.4–15.7 years), were included. The slipped hip was fixed with a smooth pin with a hook, and the non-slipped hip was prophylactically pinned. At the time of surgery, tantalum markers were installed bilaterally on each side of the growth plate through the drilled hole for the pin. Examination with radiostereometric analysis (RSA) was performed postoperatively and at 3, 6 and 12 months. The position of the epiphysis in relation to the metaphysis was calculated.ResultsAt 12 months, the epiphysis moved caudally, median 0.16 mm and posteriorly 2.28 mm on the slipped side, in comparison to 2.28 cranially and 0.91 mm posteriorly on the non-slipped side, p = 0.003 and p = 0.030, respectively. Both slipped and non-slipped epiphysis moved medially, 1.52 and 1.74 mm, respectively. A marked variation in the movement was noted, especially on the slipped side.ConclusionsThe epiphysis moved in relation to the metaphysis after smooth pin fixation, both on the slipped side and on the prophylactically fixed non-slipped side, implying further growth. The RSA method can be used to understand remodelling after ‘growth-sparing’ fixation of SCFE.

Unthreaded Fixation of Slipped Capital Femoral Epiphysis Leads to Continued Growth of the Femoral Neck.

The optimal treatment for slipped capital femoral epiphysis (SCFE) remains controversial. In Sweden, the standard treatment is unthreaded fixation over the physis, with the purpose to permit continued growth of the femoral neck. The aim of the present study was to verify and quantify longitudinal growth of the femoral neck after in situ pinning with the Hansson hook-pin. We performed a retrospective study of 54 patients treated with the Hansson hook-pin for SCFE between 2001 and 2009. The immediate postoperative radiograph and the radiograph after physeal closure (mean interval, 34 mo) were analyzed. Because the smooth Hansson hook-pin only has a grip fixation in the epiphysis, the femoral neck growth was determined as the difference in nail protrusion from the lateral cortex between the 2 radiographs. The femoral neck offset was also measured in all radiographs. Significant longitudinal growth occurred both in the slipped and the prophylactically treated contralateral hip by mean 7.1 mm (P<0.001) and 10.0 mm (P<0.001), respectively. There was no difference in growth between genders and no correlation between the amount of longitudinal growth and slip severity (range, 4.0 to 71,6 degrees; mean 27.3 degrees). Young patients (less than 11 y) grew more than older patients (more than 14 y), 12.1 vs. 4.2 mm, P=0.002. The femoral offset increased by mean 16% from mean 30.0 to 35.2 mm (P<0.001). The longitudinal growth of the femoral neck correlated with the increase in femoral offset (R=0.51, P<0.001). Unthreaded fixation of SCFE with the Hansson hook-pin allows continued growth of the femoral neck. The remaining growth enables the patient to achieve an almost anatomic offset of the hip. This is essential to optimize the abduction forces that stabilize the pelvis during gait. Future studies need to establish whether the longitudinal growth also results in improved remodelling of the proximal femur. Level III-retrospective comparative study.

Closed reduction of slipped capital femoral epiphysis

How should we treat acute/unstable slipped capital femoral epiphysis (SCFE) without the development of avascular necrosis (AVN)? To answer this question, we investigated the risk factors of AVN development after SCFE. Seventy-six hips of 64 patients were classified using two kinds of classification systems, Loder's classification based on instability and the conventional classification based on the duration of symptom, because both classifications are related to AVN development. Of 21 unstable SCFEs, seven hips developed AVN. Of 35 hips defined as acute or acute on chronic, nine hips developed AVN. Two stable SCFEs of Loder's classification developed AVN, one was acute and the other was acute on chronic. No hips of chronic SCFE developed AVN. The factor that had influenced AVN development was only closed reduction, whether purposefully or inadvertently, in an acute or unstable SCFE. On the basis of the findings of this study, one should not embark on any modality of closed reduction for an unstable or acute form of SCFE, as there is a high risk for occurrence of AVN. For the same reason, a traction table should not be used for SCFE fixation, so as to avoid an inadvertent reduction or force that can lead to AVN.

Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis

Background and purpose — Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome after fixation of slipped capital femoral epiphysis (SCFE).Methods — We identified 28 patients who were treated with fixation of SCFE from 1991 to 1998. 17 patients with 24 affected hips were willing to participate and were evaluated 10–17 years postoperatively. Median age at surgery was 12 (10–14) years. Clinical examination, WOMAC, SF-36 measuring physical and mental function, a structured interview, radiography, and MRI examination were conducted at follow-up.Results — Median preoperative Southwick angle was 22o (IQR: 12–27). Follow-up radiographs showed cam deformity in 14 of the 24 affected hips and a Tönnis grade > 1 in 1 affected hip. MRI showed pathological alpha angles in 15 affected hips, labral degeneration in 13, and chondrolabral damage in 4. Median SF-36 physical score was 54 (IQR: 49–56) and median mental score was 56 (IQR: 54–58). These scores were comparable to those of a Danish population-based cohort of similar age and sex distribution.Median WOMAC score was 100 (IQR: 84–100).Interpretation — In 17 patients (24 affected hips), we found signs of cam deformity in 18 hips and early stages of joint degeneration in 10 hips. Our observations support the emerging consensus that SCFE is a precursor of cam deformity, FAI, and joint degeneration. Neither clinical examination nor SF-36 or WOMAC scores indicated physical compromise.

Mechanical failure of single cannulated screw fixation of unstable slipped capital femoral epiphysis

Slipped capital femoral epiphysis (SCFE) is a common hip condition in adolescents, most commonly treated with in-situ cannulated screw fixation. We report two cases of cannulated screw failure within the femoral neck following SCFE fixation. To our knowledge, this is the first reported case in the literature of cannulated screw failure within the femoral neck following in-situ screw fixation for unstable SCFE. Level IV.

Implant Failure in Slipped Capital Femoral Epiphysis: A Report of Two Cases.

Slipped capital femoral epiphysis (SCFE) is a common hip disorder in adolescents. The current standard treatment in North America is percutaneous fixation with either a fully threaded or partially threaded cannulated screw1-3. Although several historical references have described implant complications4,5, failure of modern implants is rare. We present two cases of implant failure in SCFE in two adolescents. We found no other recent reports in the literature of broken partially threaded cannulated screws used for fixation of SCFE as occurred in our patients. Both patients and their parents were informed that data concerning their cases would be submitted for publication, and they all provided consent. Case 1. After three weeks of experiencing slowly progressive anterior hip pain, a fourteen-year-old boy had in situ fixation of an unstable right SCFE with a single 6.5-mm partially threaded cannulated screw (Figs. 1-A and 1-B). The initial postoperative course was uneventful. Against the advice of the surgeons, he began participating in contact sports six months after surgery. One month after resuming sports activity, the hip pain returned. Radiographs revealed that the screw was broken in the smooth shaft portion, distal to the physis and distal to the screw-shaft junction (Figs. 1-C and 1-D). No evidence of physiodesis was present. The broken portion of the screw was removed, and a 7.0-mm fully threaded screw was inserted for revision fixation. Six months later, radiographs demonstrated physeal fusion, and the patient was asymptomatic with no hip pain (Figs. 1-E and 1-F). Fig. 1-A Fig. 1-B Figs. 1-A through 1-F Radiographs of Case 1. Figs. 1-A and 1-B Fixation of SCFE with partially threaded cannulated screw. Fig. 1-C Fig. 1-D Figs. 1-C and 1-D One month after return to sports, the broken screw was seen. No …

Wachstum und Deformität nach In-situ-Fixation der Epiphyseolysis capitis femoris

For mild to moderate slipped capital femoral epiphysis (SCFE) in situ fixation is the current treatment standard. However, concerning the implant selection (screw versus k-wires) as well as the prophylactic stabilisation of the non-affected hip, controversies still exist. The aim of this study was to analyse femoral residual growth and femoral deformities after in situ fixation of SCFE either with k-wires or screws. We conducted a retrospective analysis of the radiographs of adolescents treated for SCFE in our department between 01/2003 and 02/2011. To evaluate femoral growth the articulo-trochanteric distance, centro-trochanteric distance, caput-collum-diaphyseal angle, pin-joint ratio and pin-physis ratio were determined. The femoral deformity was assessed by measuring the sphericity of the femoral head. Degenerative changes were evaluated in the final radiographs. Statistical analysis was performed concerning differences between therapeutically and prophylactically treated hips as well as stabilisations with k-wires and screws. A total of 22 patients (female : male = 14 : 8, mean age girls: 11 ± 1 years, boys: 13 ± 2 years) with 26 slipped capital femoral epiphyses was analysed. K-wires were used for fixation in 4 hips each therapeutically and prophylactically, 22 hips with SCFE and 14 non-affected hips were stabilised with screws. Treatment with screws did not lead to significantly earlier physeal closure than k-wire pinning. Regarding the femoral growth parameters a significant decrease in the articulo-trochanteric distance and CCD angle was detectable in all groups. The pin-joint ratio revealed an adequate residual growth in 58 % of the therapeutically and in 72 % of the prophylactically treated hips without significant difference between k-wires and screws. The pin-physis ratio demonstrated similar values. Regarding the femoral deformity the SCFE hips resulted in a significantly reduced sphericity, which remained unchanged during follow-up. The prophylactic stabilisation did not result in any deterioration of sphericity. The results of this study imply that further growth of the proximal femur after insertion of a sliding screw for in situ stabilisation of mild to moderate slipped capital femoral epiphysis does occur. Furthermore, an increase of deformity during follow-up through screw fixation as compared to pinning was not noticed. Hence, the assumption that screw fixation leads to permanent physeal impairment cannot be confirmed. The consideration of these results may be helpful for implant selection as well as indicating prophylactic surgery for non-affected hips.