Surgical treatment of slipped capital femoral epiphysis (SCFE) by Dunn procedure modified by Ganz: a systematic review

Modified Dunn Procedure for Open Reduction of Chronic Slipped Capital Femoral Epiphysis

Background

Abnormal femoral head anatomy following moderate-to-severe slipped capital femoral epiphysis (SCFE) can lead to femoroacetabular impingement and premature osteoarthritis4-10. Surgical correction at the deformity site through capital reorientation has the potential to fully ameliorate this but has traditionally been associated with high rates of osteonecrosis11-15. The modified Dunn procedure has the potential to restore anatomy in hips with SCFE while protecting the blood supply to the femoral head.

Description

A surgical dislocation of the hip is performed according to the technique described by Ganz et al.16. The remaining posterosuperior portion of the greater trochanter is trimmed to the level of the femoral neck by subperiosteal bone removal performed in an inside-out manner. The periosteum of the femoral neck is gradually elevated. The resulting soft-tissue flap, consisting of the retinaculum and external rotators, holds the blood vessels supplying the epiphysis. The femoral epiphysis is pinned in situ (in unstable cases) with threaded Kirschner wires, the ligamentum teres is transected, and the femoral head is dislocated. With the femoral neck exposed, the epiphysis is gradually mobilized from the metaphysis, allowing exposure of the residual femoral neck and inspection of any posteroinferior callus. To avoid tension on the retinacular vessels during reduction of the epiphysis, the posterior neck callus is completely excised. The remaining physis is removed with use of a burr while holding the epiphysis stable. The epiphysis is gently reduced onto the femoral neck, avoiding tension on the retinacular vessels. If tension is noted, the femoral neck is rechecked for residual callus, which is excised. If no callus is found, the neck may be carefully shortened in order to minimize tension. Epiphyseal fixation is achieved with use of a 3-mm fully threaded wire inserted antegrade through the fovea to the lateral cortex below the greater trochanter. A second wire is inserted retrograde under fluoroscopy. After reducing the hip, the capsule is closed and the greater trochanter is reattached with use of 3.5-mm cortical screws.

Alternatives

Alternatives include nonoperative treatment, in situ fixation (e.g., pinning or screw fixation), gentle closed reduction with pinning, and triplanar trochanteric osteotomy (e.g., Imhauser or Southwick osteotomies).

Rationale

In situ pinning of mild-to-moderate, stable SCFE yields good long-term results with low rates of osteonecrosis9. Treatment of higher-grade SCFE without reduction aims to avoid osteonecrosis and assumes that the proximal femoral deformity will remodel; however, the head-neck offset will remain abnormal, risking impingement and early-onset osteoarthritis5,8. The procedure described in the present article allows anatomic reduction of the epiphysis with a low risk of osteonecrosis. Surgical dislocation of the hip16 with development of an extended retinacular soft-tissue flap17 provides extensive subperiosteal exposure of the circumferential femoral neck and preserves the vulnerable blood supply to the epiphysis18. The Dunn subcapital realignment procedure15 with callus removal and slip angle correction allows anatomic restoration of the proximal femur.

Expected Outcomes

Reported results of various centers performing the procedure vary greatly with regard to the number of hips treated and the follow-up time. Most studies have been retrospective and have lacked a control group. The reported risk of osteonecrosis ranges from 0% to 25.9%19, with the wide range most likely because of the challenging nature of the technique, the low number of cases per surgeon, and the long learning curve associated with the procedure. In centers with extensive experience in pediatric hip-preserving surgery, the reported rate of osteonecrosis is low3. Studies with mid to long-term follow-up have shown no conversion to total hip arthroplasty3,20,21, but residual deformities can persist, and subsequent surgery is possible.

Important Tips

Extensive experience in surgical hip dislocation and retinacular flap development is a prerequisite for successful outcomes and low rates of osteonecrosis.Sufficient callus and physeal remnant resections are needed to avoid tension on the retinacular vessels during epiphyseal reduction.The skin incision should be centered over the greater trochanterThe Gibson interval must be carefully prepared for adequate release and to avoid injury.Tension on the periosteal flap should be avoided to prevent stress on the retinacular vessels.

Acronyms and Abbreviations

AP = anteroposteriorAVN = avascular necrosis (i.e., osteonecrosis)CI = confidence intervalCT = computed tomographyK-wire = Kirschner wireMRI = magnetic resonance imagingOA = osteoarthritisSHD = surgical hip dislocationTHA = total hip arthroplastyVTE = venous thromboembolism.

Slipped capital femoral epiphysis in an adolescent with congenital adrenal hyperplasia: A case report

In previous reports, hypothyroidism, hypopituitrism, and hypogonadism were common endocrine causes of SCFE, but this is the first time that congenital adrenal hyperplasia has been observed. As such, patients who have undergone long-term endocrine treatment for congenital adrenal hyperplasia could potentially be subjected to a higher risk for SCFE.

The evolution of surgical hip dislocation utilization and indications over the past two decades: a scoping review

PURPOSE

To assess the evolution of surgical hip dislocation (SHD) utilization over the past 20 years, concentrating mainly on the patients' population (adults vs. paediatric), the hip conditions treated using this approach, and reporting on complications of this procedure.

METHODS

This scoping review was conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. A PubMed database search was performed using specific search terms for articles related to SHD published between January 2001 and November 2022.

RESULTS

Initial search revealed 321 articles, of which 160 published in 66 journals from 28 countries were eligible for final analysis. The number of publications increased by 10.2 folds comparing the period from 2001 to 2005 with 2018 to 2022. USA and Switzerland contributed to more than 50% of the publications. Case series studies represented the majority of publications (65.6%). Articles including adult patients represented 73.1% of the publications while 10% were on paediatric patients; however, there was 14 folds increase in publications on paediatric patients comparing the first with the last five years. Managing non-traumatic conditions was reported in 77.5% of the articles, while traumatic conditions in 21.9%. Femoroacetabular impingement (FAI) was the most treated non-traumatic condition reported in 53 (33.1%) articles. In contrast, femoral head fractures (FHF) were the most treated traumatic condition, which was reported in 13 articles.

CONCLUSION

The publications on SHD and its usage for managing traumatic and non-traumatic hip conditions showed an increasing trend over the past two decades from worldwide countries. Its use in adult patients is well established, and its utilization in treating paediatric hip conditions is becoming more popular.

A Delphi consensus study on the treatment of slipped capital femoral epiphysis: Considerable consensus in mild and moderate slips and limited consensus in severe slips

Purpose

The aim of this expert consensus study was to establish consensus on the treatment of different types of slipped capital femoral epiphysis and on the use of prophylactic screw fixation of the contralateral unaffected side.

Methods

In this study, a four-round Delphi method was used. Questionnaires including all possible theoretical slip scenarios were sent online to 14 participants, experienced in the field of children's orthopedics and in the treatment of hip disorders in children.

Results

In-situ fixation was considered to be the first treatment choice in all types of mild slip scenarios and in moderate, stable ones. Performing in-situ fixation was not favored in moderate, unstable, and in all severe slip scenarios. In moderate to severe, unstable slip scenarios, there was consensus on the use of gentle closed or open reduction and internal fixation. Any consensus was not established in the optimal treatment of severe, stable slips. There was also consensus on the use of prophylactic screw fixation of the contralateral side in case of co-existing endocrine disorder and younger age.

Conclusions

The establishment of consensus on the treatment of all types of slipped capital femoral epiphysis even among the experienced surgeons does not seem to be possible. The severity of the slip and stability of the slip are the primary and secondary determinants of the surgeons' treatment choices, respectively. In-situ fixation is still the preferred treatment option in several slip types. Gentle capital realignment by closed or open means is recommended in displaced, unstable slips. Prophylactic screw fixation of the contralateral side is indicated under certain circumstances.

Level of evidence

level V.

Changing Treatment Philosophy of Slipped Capital Femoral Epiphysis (SCFE) after Introduction of the Modified Dunn Procedure (MDP): Our Experience with MDP and Its Complications

BACKGROUND

The modified Dunn procedure (MDP) has become popular during the last 16 years to treat severely displaced slipped capital femoral epiphysis (SCFE) while "in situ" pinning (ISP) has remained valid to treat mild to moderate SCFE, although the indication limit of the Southwick angle (SA) has not yet been established for either procedure. In this context, we reviewed two cohorts of patients with SCFE, one treated by ISP and the other by MDP. We also tried to better elucidate the etiopathogenesis of hip instability, a severe complication of MDP.

METHODS

Fifty-one consecutive patients with 62 hips affected by SCFE were treated by us from 2015 to 2019: 48 hips with a SA ≤ 40° had ISP while 14, with the SA > 40°, had MDP. The latter also had a CT scan to better investigate the SCFE morphology. Results were assessed using the Harris Hip Score.

RESULTS

The mean length of follow up of the two cohorts was 5.4 years (range: 3 to 8 years). Of the 35 hips operated by ISP with a full follow-up evaluation, 30 had an excellent or good result, 3, fair, and 2, poor. Of the 14 hips that underwent MDP, 11 had an excellent or good result, 1, fair, and 2, poor. A CT scan showed femoro-acetabular incongruency in two unstable hips following MDP.

CONCLUSIONS

We performed ISP in chronic SCFE with the SA ≤ 40° and MDP in acute and chronic SCFE with the SA > 40°, with satisfactory results. In both acute-on-chronic and chronic long-lasting SCFE with severe displacement, planned for MDP, a CT scan should be carried out to evaluate possible femoro-acetabular incongruency that may cause hip instability.