Interventional procedure consultation document

Open reduction of slipped capital femoral epiphysis

The capital femoral epiphysis is part of the rounded end (ball) at the top of the thigh bone (femur), which fits into the socket of the hip joint. During growth this can slip from its normal position, causing pain, limping and deformity. Open reduction is a surgical operation to fix the slipped epiphysis back in its correct position.

The National Institute for Health and Care Excellence (NICE) is examining open reduction of slipped capital femoral epiphysis and will publish guidance on its safety and efficacy to the NHS. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of specialist advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about open reduction of slipped capital femoral epiphysis.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website.

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination, advance equality of opportunity, and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 2 September 2014

Target date for publication of guidance: 26 November 2014

 

 

 

1                      Provisional recommendations

1.1                  The evidence on efficacy of open reduction of slipped capital femoral epiphysis is adequate. With regard to safety there is a risk of avascular necrosis. Therefore this procedure should only be used with special arrangements for clinical governance, consent and audit or research.

1.2                  Clinicians wishing to undertake open reduction of slipped capital femoral epiphysis should take the following actions.

·      Inform the clinical governance leads in their NHS trusts. Specifically, local governance arrangements should ensure that the procedure is performed only by clinicians with appropriate training and experience.

·      Ensure that patients and their parents or carers understand the potential outcomes of having or not having the procedure, in particular the risk of avascular necrosis and its consequences. In addition, the use of NICE’s information for the public [[URL to be added at publication]] is recommended.

·      Audit [URL to audit tool to be added at publication] and review clinical outcomes of all patients having open reduction of slipped capital femoral epiphysis (see section 7.1).

1.3                  Training and experience are important in preserving the blood supply to the femoral head. When the procedure is performed with surgical dislocation of the hip, clinicians should undertake their initial procedures with an experienced colleague or mentor.

1.4                  Patient selection may be complex and specialists should consider, discuss with clinical colleagues and record the balance between the potential benefits and risks of this procedure for each patient.

1.5                  Further research into open reduction of slipped capital femoral epiphysis should clearly describe details of clinical presentation (e.g Loder classification), the degree of slips, and the surgical technique; including whether surgical dislocation of the hip was performed. Outcomes from two years onwards should include degree of correction, occurrence of avascular necrosis and need for subsequent hip surgery (and its timing), especially the need for total hip replacement.

 

 

 

 

2                      Indications and current treatments

2.1                  The capital femoral epiphysis forms part of the ball-and-socket joint of the hip. In children and adolescents the ball and shaft of the femur are connected by a layer of soft cartilage, known as the growth plate, which allows for growth and hardens at adulthood. A slipped capital femoral epiphysis results in the displacement of the femoral head, usually posteriorly and inferiorly in relation to the femoral neck and within the confines of the acetabulum. This can cause knee and/or hip pain, limping and significant deformity.

2.2                  Treatment options depend on the severity of the slip. Treatment of mild to moderate slips usually involves percutaneous in-situ fixation, with or without prophylactic pinning of the contralateral hip using cannulated screws or Kirschner wires. For more severe slips, treatment options include open epiphysiodesis (fixation of the growth plate using a bone graft) combined with early intertrochanteric osteotomy to allow a full range of hip movement, or closed reduction and in-situ fixation with cannulated screws or Kirschner wires.

 

 

 

 

 

3                      The procedure

3.1                  Open reduction of slipped capital femoral epiphysis aims to relocate the capital femoral epiphysis and centre its position in the acetabulum, while minimising the risk of avascular necrosis by preserving blood vessels to the epiphysis.

3.2                  The procedure can be performed in a variety of ways, but there are 2 fundamental approaches. One approach (the Dunn approach) does not involve surgical dislocation of the hip. In the other approach (termed the Bernese or modified Dunn approach), the hip is dislocated during the procedure (Ganz surgical dislocation). This is done to create an extended retinacular flap, to provide extensive subperiosteal exposure of the circumference of the femoral neck, and thereby protect the blood supply to the epiphysis, minimising the risk of avascular necrosis.

3.3                  With the patient under general anaesthesia, an anterior or anterolateral approach is used to expose the hip and a capsulotomy is performed; at this stage, the hip may be dislocated surgically. A section of bone is then removed from the metaphysis of the femoral neck. Reduction is performed by adducting and rotating the limb, realigning the epiphysis in its normal position in the acetabulum. The realigned femoral neck is then secured with 1 or 2 cannulated screws or Kirschner wires.

 

 

 

 

 

4                      Efficacy

This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview [add URL].

4.1                  In a case series of 40 patients treated by open reduction with dislocation, mean Merle d’Aubigné–Postel scores for hip function (ranging from 3 to 18 with higher scores indicating better outcomes) were 17.8 and 17.7 for treated hips and untreated contralateral hips respectively, at mean follow-up of 5.4 years (no p values reported).

4.2                  In a case series of 28 patients treated by open reduction with dislocation, mean improvements in Hip Disability and Osteoarthritis Outcome Scores (ranging from 0 to 100 with higher scores indicating better outcomes) for pain, other symptoms, activities of daily living and quality of life were 78.6, 78.0, 78.5 and 74.8 respectively, for patients with unstable slips at mean follow-up of 38.6 months (p values <0.001). In patients with stable slips, mean improvements in Hip Disability and Osteoarthritis Outcome Scores for pain, other symptoms, activities of daily living, sports and quality of life were 45.7, 48.6, 40.9, 58.1 and 51.4 respectively (p values <0.001).

4.3                  In a case series of 110 patients (115 hips) treated by open reduction without dislocation, ‘good’ results for subjective, clinical and radiological outcomes were reported in 89% (62/70), 84% (59/70) and 71% (50/70) of hips, respectively, in hips with chronic slips and open growth plates at mean follow-up of 12 years and 11 months. In the same study ‘good’ results for subjective, clinical and radiological outcomes were reported in 74% (28/38), 71% (27/38) and 55% (21/38) of hips, respectively, in hips with acute-on-chronic slips at mean follow-up of 12 years and 11 months. In hips with chronic slips and partially fused growth plates, ‘good’ subjective, clinical and radiological results were reported in 29% (2/7), 14% (1/7) and 14.3% (1/7) of hips respectively.

4.4                  In a case series of 65 patients (66 hips) treated by open reduction without dislocation, 46% (22/48) of patients had equal leg lengths at minimum follow-up of 10 years.

4.5                  In a case series of 23 patients treated by open reduction with dislocation, mean preoperative slip angles were 47.6° whereas mean postoperative slip angles were 4.6° (p<0.0001). In the same study the mean degrees of flexion were 107.3° in treated hips and 114.8° in contralateral hips that were prophylactically pinned, at mean follow-up of 29 months (p value not significant). The mean degrees of internal rotation in treated hips and contralateral hips were 37.8° and 35.6° respectively at mean follow-up of 29 months (p value not significant).

4.6                  Specialist advisers listed key efficacy outcomes as gait parameters, pain scores, satisfactory radiological features (Stulberg I/II), incidence of salvage procedures, prevention of secondary arthritis, and a lack of leg length discrepancies.

 

 

 

 

5                      Safety

This section describes safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview [add URL].

5.1                  Avascular necrosis without chondrolysis was reported in 3% (2/70) of hips with chronic slips and open growth plates, 16% (6/38) of hips with acute-on-chronic slips, and 14% (1/7) of hips with chronic slips and fused growth plates, in a case series of 110 patients (115 hips) treated by open reduction without dislocation. In the same study avascular necrosis plus chondrolysis was reported in 1% (1/70) of hips with chronic slips and open growth plates, 8% (3/38) of hips with acute-on-chronic slips, and 14% (1/7) of hips with chronic slips and fused growth plates. Chondrolysis alone was reported in 7% (5/70) of hips with chronic slips and open growth plates, 3% (1/38) of hips with acute-on-chronic slips, and 43% (3/7) of hips with chronic slips and fused growth plates.

5.2                  Avascular necrosis was reported in 12% (2/17) of patients with unstable slips and 0% of patients with stable slips in the case series of 28 patients treated by open reduction with surgical dislocation.

5.3                  Osteoarthritis was reported in 40% (19/48) of hips at mean follow-up of 16 years in the case series of 65 patients (66 hips) treated by open reduction without dislocation: 19% (9/48) of hips developed grade I osteoarthritis, 6% (3/48) developed grade II osteoarthritis and 15% (7/48) developed grade III osteoarthritis.

5.4                  Implant-associated problems, in hips with severe slipped capital femoral epiphysis, were reported in 46% (10/22) of hips treated by open reduction without dislocation and 0% of hips treated by epiphysiodesis plus osteoplasty, in the non-randomised comparative study of 48 patients (53 hips): 4 patients had penetration of the joint surface by 1 or more pins, 4 had lateral pin discomfort, 1 had pin loosening and surgeons were unable to remove a pin from the hip of 1 patient. The timings of these complications were not reported.

5.5                  Reoperation, 6 to 8 weeks after surgery, was needed in 8% (3/40) of patients because of breakage of screw or wire fixations in the case series of 40 patients treated by open reduction with dislocation.

5.6                  Permanent partial paralysis of the sciatic nerve was reported in 1 patient in the case series of 65 patients (66 hips) treated by open reduction without dislocation.

5.7                  Wound infections were reported in 3% (2/66) of hips in the case series of 65 patients (66 hips) treated by open reduction without dislocation.

5.8                  Delayed union of the femoral neck was reported in 8% (3/40) of patients in the case series of 40 patients treated by open reduction with dislocation. No further details were provided.

5.9                  Heterotrophic ossification was reported in 8% (3/40) of patients in the case series of 40 patients treated by open reduction with dislocation. No further details were provided.

5.10               Specialist advisers listed stiffness and fracturing around implants as anecdotal adverse events and highlighted non-union of the femoral neck as a theoretical adverse event.

 

 

 

 

6                      Committee comments

6.1                  The Committee noted that different techniques have been used to perform open reduction of slipped capital femoral epiphysis. It was advised that the procedure has evolved over the years with a particular view to reducing the risk of avascular necrosis.

 

 

 

 

7                      Further information

7.1                  This guidance requires that clinicians undertaking the procedure make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
June 2014

 

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