The contralateral slip

Does Prophylactic Pinning Affect the Proximal Femur Morphology in Slipped Capital Femoral Epiphysis?

Background

The role of prophylactic pinning of the contralateral hip in unilateral SCFE is well established in patients with risk factors for developing contralateral slip. The effect of prophylactic pinning on the growth and morphology of the hip is not well documented in the literature. We aimed to study the effect of prophylactic pinning on the residual growth and morphology of the proximal femur.

Materials & Methods

The institutional database was searched for all unilateral SCFE cases for the period 2011 to 2020. A total of 171 unilateral SCFE cases were identified. All the radiographs were scanned and those patients who had follow-up X-rays till skeletal maturity were included in the study. Prophylactic pinning was performed using 6.5 mm fully threaded cancellous screws in supine position on a radiolucent table. The following radiological parameters were measured on the post-operative X-rays and at skeletal maturity: (i) neck length (NL), (ii) neck-shaft angle (NSA), (iii) femoral offset (FO), (iv) articulo-trochanteric distance (ATD) and (iv) tip-apex distance (TAD) by two different observers.

Results

The mean age of the cohort was 13.7 years. ATD decreased from the mean value of 25.67 mm in post-operative radiographs to 20.84 mm in final follow-up radiographs. The NL, FO, and TAD were found to be increasing with age with mean final follow-up values of 55.35 mm, 41.41 mm, and 6.19 mm respectively compared to post-operative mean values of 50.95 mm, 37.4 mm, and 4.69 mm. There was no significant change in the neck-shaft angle. The mean post-operative NSA was 132.9° and it was 131.8° at final follow-up radiographs.

Conclusion

Prophylactic pinning in unilateral SCFE does not stop the growth of the proximal femur completely. The ATD decreases in all the patients with prophylactic screw fixation probably due to the discrepancy in growth between the trochanteric apophysis and proximal femoral physis. The clinical effects of this subtle change in the morphology of the proximal femur need further investigation.

Level of Evidence

Level IV Case series.

Prophylactic fixation of the unaffected contralateral side in children with slipped capital femoral epiphysis seems favorable: A systematic review

BACKGROUND

Slipped capital femoral epiphysis (SCFE) occurs in adolescents and has an incidence of around 10 per 100000 children. Children presenting with a unilateral SCFE are 2335 times more likely to develop a contralateral SCFE than the general population. Prognostic factors that have been suggested to increase the risk of contralateral slip include a younger patient, an underlying endocrine disorder, growth hormone use and a higher radiographic posterior sloping angle. However, there is still much debate on the advantages and disadvantages of prophylactic fixation of the unaffected side in an otherwise healthy patient.

AIM

To investigate the risk rate of contralateral SCFE and assess the (dis)advantages of prophylactic fixation of the contralateral hip.

METHODS

A systematic literature search was performed in the Embase, Medline, Web of Science Core Collection and Cochrane databases. Search terms included ‘slipped capital femoral epiphysis,’ ‘fixation,’ ‘contralateral,’ and derivatives. The eligibility of the acquired articles was independently assessed by the authors and additional relevant articles were included through cross-referencing. Publications were considered eligible for inclusion if they presented data about otherwise healthy children with primarily unilateral SCFE and the outcomes of prophylactically pinning their unaffected side, or about the rates of contralateral slips and complications thereof. The study quality of the included articles was assessed independently by the authors by means of the methodological index for non-randomized studies criteria.

RESULTS

Of 293 identified unique publications, we included 26 studies with a total of 12897 patients. 1762 patients (14%) developed a subsequent symptomatic contralateral slip. In addition, 38% of patients developed a subsequent slip on the contralateral side without experiencing clinical symptoms. The most outspoken advantage of prophylactic fixation of the contralateral hip in the literature is prevention of an (asymptomatic) slip, thus reducing the increased risk of avascular necrosis (AVN), cam morphology and osteoarthritis. Disadvantages include an increased risk of infection, AVN, peri-implant fractures, loss of fixation as well as migration of hardware and morphologic changes as a consequence of growth guidance. These risks, however, appeared to only occur incidentally and were usually mild compared to the risks involved with an actual SCFE.

CONCLUSION

The advantages of prophylactic pinning of the unaffected side in otherwise healthy patients with unilateral SCFE seem to outweigh the disadvantages. The final decision for treatment remains to be patient-tailored.

Is There an Optimal Recovery Step Landing Zone Against Slip-Induced Backward Falls During Walking?

Recovery stepping in response to forward slips has the potential to not only rebuild the base of support to prevent backward falling, but also provide extra limb support to prevent downward falling. Hence, recovery stepping is often necessary for fall prevention following an unexpected slip. However, less is known about whether recovery foot placement could affect the likelihood of recovery following a slip. The purpose of this study was to determine whether there is an optimal recovery landing zone within which older adults have a higher likelihood of recovery. 195 participants experienced a novel, unannounced forward slip while walking on a 7-m walkway. The center of mass (COM) stability (computed from its position and velocity), vertical limb support (computed from change in hip kinematics), and recovery limb joint moments (computed from joint kinematics and ground reaction force) in the sagittal plane were analyzed. The results showed that a longer distance between recovery foot landing position and the projected COM position at recovery foot touchdown (relative recovery step placement) was conducive to stability improvement but adverse to limb support enhancement, and vice versa for a shorter distance. Relative recovery step placement could predict the recovery likelihood with an accuracy of 67.3%, and the recovery rate was greater than 50% when the distance between recovery foot and COM is less than 0.3 × foot length. This study also found more posterior stepping could be attributed to insufficient ankle plantar flexor and hip flexor moments in the pre-swing phase, while more anterior stepping was induced by insufficient hip and knee extensor moments in the following swing phase.

Capsulotomy in Unstable Slipped Capital Femoral Epiphysis and the Odds of AVN: A Meta-analysis of Retrospective Studies

BACKGROUND

Unstable slipped capital femoral epiphysis (SCFE) may lead to avascular necrosis (AVN) in up to 60% of patients. The aim of this study was to assess the best clinical evidence to determine the effect of capsular decompression (CD) on odds of AVN in unstable SCFE.

METHODS

Medline, Embase, and Cochrane databases were systematically searched for comparative studies investigating AVN rates in unstable SCFE treated with or without CD (aspiration, percutaneous, or open). Quality was evaluated by the Newcastle Ottawa Scale. A comparative analysis with pooled effect estimates using random-effects modeling was calculated. Secondary analysis pooled AVN rates from both comparative studies and case series.

RESULTS

Comparative analysis included 17 retrospective studies with 453 hips (201 with CD, 252 without CD). Thirty-four of 201 (17%) hips with CD developed AVN, while 67 of 252 (27%) hips without CD developed AVN. The odds of AVN for patients treated with or without CD [odds ratio=0.80, 95% confidence interval (CI): 0.48-1.35] was not statistically different. Subanalysis on patients treated with in situ pinning or positional reduction and pinning showed no difference in AVN rates with or without CD (odds ratio=0.97, 95% CI: 0.44-2.10). In the secondary analysis of 17 comparative studies and 23 case series, the average rate of AVN was 17%, 0.17 (95% CI: 0.13-0.23) for patients treated with CD (60/447 hips) and 28%, 0.28 (95% CI: 0.22-0.35) for patients treated without CD (129/464 hips).

CONCLUSIONS

There was no statistically significant decrease in odds of AVN with CD. However, studies were limited by their retrospective nature and inadequate documentation of CD techniques; the majority lacked femoral head blood flow monitoring to demonstrate adequate decompression. Future prospective studies with carefully documented complete decompression may help to elucidate the effect of CD on AVN risk. Although there was no statistically different odds of AVN with or without CD, even this large meta-analysis was underpowered, and one cannot conclude that there was truly no difference in odds of AVN without an appropriately powered study. Therefore, we recommend routine CD for all unstable SCFEs pending additional research, as CD adds little to the surgical procedure and may minimize the risk of a devastating insult to the femoral head.

Outcomes after slipped capital femoral epiphysis: a population-based study with three-year follow-up

PURPOSE

To evaluate outcomes three years after treatment for slipped capital femoral epiphysis (SCFE): development of avascular necrosis (AVN), subsequent surgery, hip function and the contralateral hip.

METHODS

This prospective cohort study included a total national population of 379 children treated for SCFE between 2007 and 2013. A total of 449 hips treated for SCFE and 151 hips treated with a prophylactic fixation were identified. The Barnhöft questionnaire, a valid patient-reported outcome measure (PROM), was used.

RESULTS

In all, 90 hips had a severe slip, 61 of these were clinically unstable. AVN developed in 25 of the 449 hips. Six of 15 hips treated with capital realignment developed AVN. A peri-implant femur fracture occurred in three slipped hips and in two prophylactically pinned hips. In three of these five hips technical difficulties during surgery was identified. In 43 of 201 hips scheduled for regular follow-up a subsequent SCFE developed in the contralateral hip. Implant extraction after physeal closure was performed in 156 of 449 hips treated for SCFE and in 51 of 151 prophylactically fixed hips. Children with impaired hip function could be identified using the Barnhöft questionnaire.

CONCLUSION

Fixation in situ is justified to remain as the primary treatment of choice in SCFE. Overweight is more common in children with SCFE than in the average population. Prophylactic fixation is a safe procedure when performed using a correct technique. The number of patients who developed AVN after capital realignment is of concern. We recommend rigorous follow-up of both hips, including PROM evaluation, until physeal closure.

LEVEL OF EVIDENCE

II - prospective cohort study.

Severity of Asynchronous Slipped Capital Femoral Epiphyses in Skeletally Immature Versus More Skeletally Mature Patients

BACKGROUND

Routine prophylactic screw fixation for skeletally immature patients with slipped capital femoral epiphysis (SCFE) continues to be debated. The purpose of this study was to assess the slip severity of a second SCFE in skeletally immature versus more mature patients and determine necessity of contralateral hip prophylactic screw fixation.

METHODS

All patients treated for SCFE at 3 pediatric hospitals over a 10-year time period (January 1, 2002 to December 31, 2011) were evaluated. Patients were included if they had a unilateral SCFE and a contralateral asynchronous SCFE, and were divided into immature (Oxford triradiate score 1) versus more mature (Oxford triradiate score 2 and 3) groups. Data evaluation included age, time between slips, body mass index, Southwick angles of first then second SCFEs, and follow-up duration.

RESULTS

There were a total of 45 patients: 16 patients in the skeletally immature and 29 patients in the more mature group. Average age at first SCFE in immature patients was 10.9 years and in more mature patients 12.1 years (P=0.70). Age at second SCFE in immature patients was 11.5 years and in more mature patients 13.0 years (P=0.023). Average time between SCFEs was 6.6 months for immature and 11.4 months for more mature patients (P=0.093). Southwick angles for immature patient first and second SCFEs were 25 and 12.9 degrees, respectively, and for more mature patient first and second SCFEs were 31 and 21 degrees, respectively. Southwick angles were higher at first and second slips in the more mature group, significant only at the second slip (P=0.032). SCFE severity at initial event was predictive of severity of second SCFE regardless of maturity (P=0.043). Regression analysis of slip severity against multiple patient factors demonstrated triradiate score was not a factor assessing subsequent SCFE magnitude (P=0.099).

CONCLUSIONS

There was no significant difference between first and second SCFEs regardless of skeletal maturity but severity of initial SCFE did correlate with severity of the second SCFE. Deciding not to prophylactically pin an unaffected hip does not lead to worse deformity if a second SCFE occurs in skeletally immature or more mature patients, unless the initial event is severe. Prophylactic pin fixation in skeletally immature patients should occur as a shared decision between patient, guardians, and treating surgeon.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Outcome of the unaffected contralateral hip in unilateral slipped capital femoral epiphysis: a report comparing prophylactic fixation with observation

This was a retrospective review of 80 patients with unilateral slipped capital femoral epiphysis treated with either prophylactic fixation or observation. The unaffected hip of 44 patients (mean age 12.6 years) were subjected to simultaneous prophylactic fixation and 36 patients (mean age 13.4 years) were managed by observation. Fisher's exact test showed a significantly high incidence of sequential slip of unaffected hips in the observation group in comparison with prophylactic fixation (P=0.002). No cases had avascular necrosis or chondrolysis. Prophylactic fixation significantly reduces the incidence of sequential slip. It outweighs the minimal surgical risks compared with its benefit in the prevention of further sequential slip.

Prophylactic pinning for slipped capital femoral epiphysis: does it affect proximal femoral morphology?

This study was designed to determine whether prophylactic pinning of the unaffected hip in unilateral slipped capital femoral epiphysis affects the proximal femoral morphology. Twenty-four hips prophylactically pinned were compared with 26 cases observed. The articulotrochanteric distance (ATD) and the trochanteric-trochanteric distance (TTD) were measured. Postoperative radiographs were compared with final follow-up radiographs. The final TTD : ATD ratio was higher (P=0.048) in the pinned group, suggesting relative coxa vara/breva. There was a smaller difference between the two hips in the prophylactically pinned group (0.7) as opposed to those observed (1.47). Prophylactic pinning does not cause growth to stop immediately but alters the proximal femoral morphology.

Slipped capital femoral epiphysis

Controversy remains whether the contralateral hip should be fixed in patients presenting with unilateral slipped capital femoral epiphysis (SCFE). This retrospective study compares the outcomes and cost of those patients who had prophylactic fixation with those who did not.

Between January 2000 and December 2010 a total of 50 patients underwent unilateral fixation and 36 had prophylactic fixation of the contralateral hip. There were 54 males and 32 females with a mean age of 12.3 years (9 to 16). The rate of a subsequent slip without prophylactic fixation was 46%. The risk of complications was greater, the generic health measures (Short Form-12 physical (p < 0.001) and mental (p = 0.004) summary scores) were worse. Radiographic cam lesions in patients presenting with unilateral SCFE were only seen in patients who did not have prophylactic fixation. Furthermore, prophylactic fixation of the contralateral hip was found to be a cost-effective procedure, with a cost per quality adjusted life year gained of £1431 at the time of last follow-up.

Prophylactic fixation of the contralateral hip is a cost-effective operation that limits the morbidity from the complications of a further slip, and the diminished functional outcome associated with unilateral fixation.

Cite this article: Bone Joint J 2015;97-B:1428–34.

Persisting growth after prophylactic single-screw epiphysiodesis in upper femoral epiphysis

BACKGROUND

Prophylactic fixation of the contralateral hip in cases of slipped upper femoral epiphysis is controversial. Therefore, using a single-cannulated screw has been widely accepted. However, differing reports exist on the occurrence of persisting growth after prophylactic epiphysiodesis. The aim of this retrospective study was to evaluate the presence of persisting growth of the upper femoral epiphysis after prophylactic fixation.

METHODS

From 2006 until 2009, 11 children underwent prophylactic pinning using a single-cannulated 6.5-mm cancellous screw. Time to fusion, persisting growth, and overgrowing of the screw were measured on plain radiographs taken postoperatively and at least after the growth plate was fused.

RESULTS

All patients except 1 (91%) showed a persisting growth of the epiphysis, and in 2 cases a hardware replacement was necessary. The mean increase of the femoral neck length was 8.2% (SEM 1.46%). Mean follow-up was 37 months (range, 12 to 49 mo). All patients had a Risser sign grade 0 at the time of surgery, and equal or less than grade 3, when the growth plate was fused.

CONCLUSIONS

Despite previous reports that a prophylactic fixation using a single-cannulated cancellous screw is unproblematic and safe, we showed that in our series growth persistence was the rule and in some cases the physeal overgrowth necessitates a hardware replacement. Careful follow-up until fusion of the growth plate should be recommended.

What is the best evidence for the treatment of slipped capital femoral epiphysis?

BACKGROUND

There are many different treatment methods for slipped capital femoral epiphysis (SCFE). It was the purpose of this study to review the results from the literature for different methods of SCFE treatment and on the basis of level of evidence determine the current best evidence treatment.

METHODS

A systematic review of the literature was undertaken. Treatment results were grouped into 2 categories. The first was all methods without surgical hip dislocation, and the second was all methods in which surgical dislocation was used.

RESULTS

For stable SCFEs without surgical dislocation, the best recommended treatment (mostly level IV) recommends in situ single screw fixation over multiple pin fixation, epiphysiodesis, osteotomy, or spica cast. For the unstable SCFEs without surgical dislocation (all level IV), the best recommended treatment is urgent reduction with decompression and internal fixation. For both stable and unstable SCFEs, the short-term small series in the literature (all level IV) does not demonstrate an advantage or improvement in outcomes compared with in situ single screw fixation for stable SCFE and urgent reduction, decompression, and internal fixation in unstable SCFEs.

CONCLUSIONS

A systematic review of the literature recommends on the basis of level of evidence that the best treatment for a stable SCFE is single screw in situ fixation and for unstable SCFEs urgent gentle reduction, decompression, and internal fixation.

LEVEL OF EVIDENCE

Level IV, systematic review of level IV studies.

Management of the contralateral hip in patients with unilateral slipped upper femoral epiphysis: to fix or not to fix--consequences of two strategies

In the majority of patients with slipped upper femoral epiphysis only one hip is involved at primary diagnosis. However, the contralateral hip often becomes involved over time. There are no reliable factors predicting a contralateral slip. Whether or not the contralateral hip should undergo prophylactic fixation is a matter of controversy. We present a number of essential points that have to be considered both when choosing to fix the contralateral hip prophylactically as well as when refraining from surgery and instead following the patients with repeat radiographs.

COMPARISON OF THE FEMORAL HEAD HEIGHT/NECK LENGTH RATIO BETWEEN THE UNAFFECTED HIP OF PATIENTS WITH A UNILATERAL SLIPPED FEMORAL HEAD AND THE HIPS OF INDIVIDUALS WITHOUT A SLIPPED FEMORAL HEAD

Objective – To compare the head/neck ratio on the contralateral side of patients with a unilateral slipped capital femoral epiphysis (SCFE) with control individuals. Methods – Seventeen patients who were followed up at the Department of Orthopedics and Traumatology, Federal University of São Paulo, Brazil, between 1985 and 2007, were assessed. The control group consisted of 34 individuals from the same place who were matched for gender and age, with a history of trauma that necessitated pelvic radiography. The femoral head height and femoral neck measurements were made using simple pelvic radiography in accordance with the criteria of Bleck (1983), on both sides in the control group and on the contralateral hip in the patients. Nonparametric statistics were used, with a p-value ≤ 0.05. Results – There was no difference in the distribution of age, gender, body mass index and bone age between the groups. The head/neck ratio on the right and left side in the controls did not differ (p = 0.64). However, the head/neck ratio from the contralateral hip of the patients with SCFE was significantly lower than that of the control group (p = 0.00). Conclusion – The significantly lower head/neck ratio in the patients with epiphysiolysis could be indicative of a risk of SCFE.

Prognostic significance of stability in slipped upper femoral epiphysis: a systematic review and meta-analysis

OBJECTIVE

To examine associations of major complications after surgical treatment of slipped upper femoral epiphysis (SUFE) with condition- and treatment-related risk factors.

STUDY DESIGN

This systematic review and meta-analysis of observational studies used an electronic literature search of Embase and Medline supplemented by a manual search of bibliographies. The studies enrolled children and adolescents with SUFE, defined stable and unstable disease, and reported at least 3 primary endpoints: avascular necrosis (AVN), chondrolysis, and reoperation. Random-effects meta-regression analysis was performed when possible.

RESULTS

The weighted risk for AVN, derived from intercept-only meta-regression, was estimated as 5.3% (95% confidence interval [CI], 3.4%-7.2%). Patients with unstable slips had a 9.4-fold greater risk of developing AVN. Instability proved to be an independent predictor for AVN. The weighted risk of chondrolysis was 0.8% (95% CI, 0.2%-1.4%), associated with unstable slips and osteotomies. The risk of reoperation was estimated at 5.5% (95% CI, 1.7%-9.3%). Loss of fixation was the primary reason for reoperation.

CONCLUSIONS

Current evidence indicates that unstable slips are at a significantly higher risk for AVN than stable slips, regardless of the attempted surgical approach. Little clinical information is available regarding chondrolysis and reoperation in relation to the stability of the physis.

Review of the Management Outcome of Slipped Capital Femoral Epiphysis and the Role of Prophylactic Contra-lateral Pinning Re-examined

Introduction: Slipped capital femoral epiphysis is the most common hip problem in the adolescent age group. It can involve both hips, presenting itself bilaterally at first presentation or sequentially. The overall incidence of bilateral disease is variable, but the risk of occurrence is higher when there is underlying endocrinopathy, renal disease and obesity. Materials and Methods: Amongst the 36 cases (44 hips) of slipped capital femoral epiphysis that we had, there were 8 cases of bilateral disease, of which 3 were bilateral sequential slips. A retrospective review of all case records and X-rays was done. Results: According to Aadalen’s criteria, the results were excellent or good in 37 hips, fair in 3 hips, and poor in 2 hips. Two patients were considered as treatment failure because of avascular necrosis. The incidence of bilateral slipped capital femoral epiphysis was 22.2%. The overall average age was 11.4 years. All cases of sequential involvement presented within 15 months of the initial slip. One patient had hypothyroidism (who also had a positive family history for slipped capital femoral epiphysis), while 91.6% were above the 75th percentile for weight. There was no statistically significant difference in age, sex, race, body mass index (BMI) and weight percentile distribution between patients with unilateral and bilateral disease. Conclusion: Satisfactory outcomes can be expected in most patients treated for slipped capital femoral epiphysis. The risk of avascular necrosis is higher in unstable slips. The role of prophylactic contra-lateral pinning should be restricted to patients with hypothalamic-pituitary-ovarian axis disease, especially hypothyroidism. Key words: Asian, Bilateral, Hypothyroidism

Screw placement in slipped upper femoral epiphysis: is good the enemy of better?

Introduction and aims A single hip screw is the recommended method of fixation for slipped upper femoral epiphysis (SUFE). Current practice favours the placement of the screw in the centre of the femoral head on both anteroposterior and lateral planes to avoid the risks of chondrolysis and avascular necrosis (AVN). We investigated the correlation between different positions of the screw in the femoral head and the prevalence of AVN, chondrolysis, late slippage and the time to epiphyseal closure. Methods The clinical notes and radiographs of 38 consecutive patients (61 hips) who underwent single screw fixation for SUFE were evaluated retrospectively with a mean follow-up of 36 months. Two-way ANOVA and the post hoc test was performed to analyse the correlation between the different variables and the outcome at the 5% level of significance. Results There were 16 acute slips, 18 chronic slips and ten acute-on-chronic slips. Seventeen slips were treated prophylactically. Mild slip was encountered in 39 hips, moderate slip in four and severe slip in one. The central-central position was only achieved in 51% of cases. The most significant results of the study were as follows: (1) no significant difference between the time to epiphyseal closure and the position of the screw, and (2) no late slippage or chondrolysis was observed in our series. Conclusion Our results showed that the positioning of the screw other than in the centre of the femoral head has the ability to provide physeal stability and has no correlation with the timing to closure of the epiphysis and the risk of avascular necrosis or chondrolysis. We therefore recommend that other positions be considered if the "optimal central-central position" is not initially achieved - specifically for the treatment of mild slip - as the potential hazards from several attempts to achieve the optimum position outweigh the benefits.