Similar femoral growth and deformity with one screw versus two smooth pins for slipped capital femoral epiphysis

Temporal trends in surgical implants for in situ fixation of stable slipped capital femoral epiphysis

Stable slipped capital femoral epiphysis (SCFE) is a pediatric hip disorder managed with in situ fixation of the proximal femoral epiphysis, otherwise known as 'pinning the hip'. The objective of this study was to characterize how the choice of implant for in situ fixation of stable SCFE has changed over time. A systematic review of publications concerning in situ fixation of stable SCFE from January 1993 to November 2021 was conducted. The change in the type, diameter, and number of implants used in publications over time and the age of their respective patient cohorts was evaluated. A total of 207 articles met inclusion criteria. There was an increase in publications using cannulated screws over time ( P  = 0.0113). As the yearly percentage of publications using threadless non-cannulated implants decreased ( P  = 0.0309), the percentage using cannulated screws increased ( P  = 0.0047). Single-implant fixation also increased ( P  = 0.0409). While there was no difference in the rate of increase of implants < 7 mm or ≥ 7 mm in diameter ( P  = 0.299), patients with larger-diameter implants were, on average, older than patients with smaller-diameter implants ( P  = 0.0462). In general, the age of patients undergoing in situ fixation of stable SCFE has not changed ( P  = 0.595). Irrespective of patient-specific considerations, single cannulated screws have become the implant of choice for in situ fixation of stable SCFE. There has not been a consensus on the optimal implant diameter; instead, patient-specific considerations are of paramount importance in this decision.

The Free-Gliding screw for slipped capital femoral epiphysis : is it safe, does it glide, and does age matter?

AIMS

Fixation techniques used in the treatment of slipped capital femoral epiphysis (SCFE) that allow continued growth of the femoral neck, rather than inducing epiphyseal fusion in situ, have the advantage of allowing remodelling of the deformity. The aims of this study were threefold: to assess whether the Free-Gliding (FG) SCFE screw prevents further slip; to establish whether, in practice, it enables lengthening and gliding; and to determine whether the age of the patient influences the extent of glide.

METHODS

All patients with SCFE who underwent fixation using FG SCFE screws after its introduction at our institution, with minimum three years' follow-up, were reviewed retrospectively as part of ongoing governance. All pre- and postoperative radiographs were evaluated. The demographics of the patients, the grade of slip, the extent of lengthening of the barrel of the screw and the restoration of Klein's line were recorded. Subanalysis was performed according to sex and age.

RESULTS

A total of 19 hips in 13 patients were included. The mean age of the patients at the time of surgery was 11.5 years (9 to 13) and the mean follow-up was 63 months (45 to 83). A total of 13 FG SCFE screws were used for the fixation of mild or moderate SCFE, with six contralateral prophylactic fixations. No hip with SCFE showed a further slip after fixation and there were no complications. Lengthening occurred in 15 hips (79%), with a mean lengthening of the barrel of 6.8 mm (2.5 to 13.6) at final follow-up. Remodelling occurred in all hips with lengthening of the barrel. There was statistically more lengthening in patients who were aged < 12 years, regardless of sex (p = 0.002).

CONCLUSION

The FG SCFE screw is effective in preventing further slip in patients with SCFE. Lengthening of the barrel occurred in most hips, and thus allowed remodelling. This was most marked in younger children, regardless of sex. Based on this study, this device should be considered for use in patients with SCFE aged < 12 years instead of standard pinning in situ.Cite this article: Bone Joint J 2023;105-B(2):215-219.

[Femoroacetabular impingement syndrome in adolescents-How to adivse? How to treat?]

Hintergrund

Das Femoroazetabuläre Impingement-Syndrom (FAIS) ist eine relevante Ursache für Leistenschmerzen beim Jugendlichen. Insbesondere sind Sportler betroffen.

Ziel der Arbeit

Die Arbeit soll einen evidenzbasierten Hintergrund für Beratung und Therapie des FAIS beim Adoleszenten bieten.

Material und Methoden

Anhand der aktuellen Literatur wurde eine Übersicht zu Prävalenz und Pathogenese, Abklärung und Diagnostik sowie therapeutischen Empfehlung des FAIS beim Adoleszenten erarbeitet.

Ergebnisse und Diskussion

Das FAIS beim Jugendlichen betrifft vor allem sportlich aktive Patienten. Bestimmte Sportarten begünstigen die Entstehung eines FAIS. Cam-Impingement, Pincer-Impingement und kombiniertes FAIS sind die häufigsten Entitäten in dieser Altersgruppe. Die Cam-Morphologie entsteht kurz vor Schluss der proximalen Femurwachstumsfuge. Beim Cam-Impingement muss die Epiphyseolysis capitis femoris (ECF) von der primären Cam-Morphologie unterschieden werden. Die ECF verlangt eine rasche operative Versorgung mit Stabilisierung der Epiphyse, während das primäre Cam-Impingement elektiv abgeklärt werden kann und ein konservativer Behandlungsversuch sinnvoll ist. Schäden an Labrum und Knorpel werden regelhaft beobachtet. Eine systematische radiologische Abklärung mittels Projektionsröntgen und MRT ist obligat, um einen adäquaten Therapieplan zu entwickeln. Bei jugendlichen Patienten mit FAIS sollte immer ein konservativer Therapieversuch erfolgen. Ist dieser nicht erfolgreich, ist die operative Sanierung mit Hüftarthroskopie indiziert. Die postoperativen Ergebnisse zeigen bei Jugendlichen sehr gute Erfolge mit rascher Besserung der Beschwerden, geringen Komplikationen und einer hohen „Return-to-sport“-Rate.

Outcomes of distally un-threaded screw fixation of slipped capital femoral epiphysis at skeletal maturity: a matched cohort study

The most common treatment for slipped capital femoral epiphysis worldwide is in situ fixation with a threaded screw. Un-threaded screws are designed to prevent slip progression without hindering residual growth of the proximal femur. This study aimed to compare growth, remodelling and long-term outcomes after fixation with un-threaded screws and a matched cohort of patients treated with a standard screw. Six patients (nine hips) treated with un-threaded screws and 16 patients (21 hips) treated with standard screws matched for age, skeletal maturity, sex and Southwick angle were recruited. Clinical records were reviewed for patient demographics, medical history and complications. Radiographs were reviewed for residual growth and time to physeal closure. Growth velocity was calculated. Absence of cam deformity signified complete remodelling. Clinical assessment was graded from excellent to poor and patient-reported outcomes were recorded. There was significantly more growth recorded in the un-threaded screw group in femoral neck length (7.6 mm, P = 0.003), articulo-lesser trochanter distance (5.3 mm, P = 0.028), pin-joint ratio (7.439%, P = 0.006) and pin-physis ratio (8.244%, P = 0.001). The probability of revision operations due to ongoing growth was higher in this group (risk ratio: 6.57, P = 0.0008). Time to physeal closure was not significantly different, but growth velocity was significantly higher in the un-threaded group. The lower probability of cam deformity was not significant. Functional and clinical results were not significantly different at average 11.2 years' follow-up. Un-threaded screws allow for significantly more growth than standard threaded screws. The un-threaded screw could not be recommended due to the higher re-operation rates, without any proven benefit.

[Fixation techniques for slipped capital femoral epiphysis : Principles, surgical techniques, and complications]

The purpose of this review is to present the pros and cons as well as the surgical techniques of conventional implants used for fixation of slipped capital femoral epiphysis (SCFE). Worth mentioning are K‑wires, Hansson pins, transfixing screws, and gliding screws. We searched PubMed for "ECF" and "SCFE" in combination with "in situ fixation," "pin," "wire," "screw," and "nail." We considered Johansson nail, Knowles pin, and Nyström nail to be obsolete and of historical interest only. We noticed a trend from absolute stability towards some form of dynamic fixation over time, likely related to considerations of growth disturbance of the proximal femur and also the inherent potential for remodeling with time.