• Users Online: 464
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
CASE REPORT
Year : 2021  |  Volume : 7  |  Issue : 2  |  Page : 142-144

Limb lengthening of a rare case of congenital femoral deficiency with an unstable knee


1 Department of Orthopaedic, Hospital da Senhora da Oliveira, Guimarães, Portugal
2 Department of Orthopaedic, Centro Hospitalar Universitário do Porto, Porto, Portugal
3 Department of Orthopaedic, Centro Hospitalar Universitário do Porto; Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal
4 Department of Orthopaedic, Centro Hospitalar Tâmega e Sousa, Penafiel, Portugal

Date of Submission01-Aug-2021
Date of Decision11-Sep-2021
Date of Acceptance18-Nov-2021
Date of Web Publication30-Dec-2021

Correspondence Address:
Dr. Ricardo Marta
Hospital da Senhora da Oliveira, Guimarães
Portugal
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jllr.jllr_23_21

Rights and Permissions
  Abstract 


Congenital femoral deficiency (CFD) is a rare birth defect that is characterized by a short femur, associated with hip and knee deformity, deficiency, or instability. Children with severe CFD may need multiple deformity correction or lengthening procedures to reduce axial malalignment and limb length discrepancy (LLD). During limb lengthening, it can occur knee subluxation or dislocation, a severe treatment-related complication. We report a 15-year-old girl with a CFD with a previous episode of posterior subluxation of the knee during a femoral lengthening using a monolateral external fixator. She had a 13 cm LLD and coxa vara; therefore, it was applied a knee spanning Ilizarov fixator with a double osteotomy of the femur for gradual correction. At 11 months following Ilizarov application, a complete correction was achieved, and the circular fixator was removed. Knee joints of patients with CFD show highly variable grades of instability. Adequate surgical techniques, preventive measures, and early detection of signs of subluxation can lead to good functional results. Femur lengthening with a preventive bridging of the knee with an Ilizarov frame is a safe and effective way of treating patients with CFD.

Keywords: Circular external fixation, congenital femoral deficiency, Ilizarov, knee instability, knee subluxation, limb lengthening


How to cite this article:
Marta R, Campos A, Oliveira A, Carvalho J. Limb lengthening of a rare case of congenital femoral deficiency with an unstable knee. J Limb Lengthen Reconstr 2021;7:142-4

How to cite this URL:
Marta R, Campos A, Oliveira A, Carvalho J. Limb lengthening of a rare case of congenital femoral deficiency with an unstable knee. J Limb Lengthen Reconstr [serial online] 2021 [cited 2022 May 24];7:142-4. Available from: https://www.jlimblengthrecon.org/text.asp?2021/7/2/142/334384




  Introduction Top


Congenital femoral deficiency (CFD) is a rare and complex condition that is frequently associated with other congenital anomalies. CFD may be associated with bowing of the shaft, pseudoarthrosis of the femoral neck, coxa vara, acetabular dysplasia, hypoplasia at the femoral condyle, genu valgum, hypoplastic patella, and absence of the cruciate ligaments.[1] There are variable degrees of severity of dysplasia of the femur.[2],[3] Limb lengthening is an appropriate option when there are mobile hip and knee joints.[4],[5],[6] Children with severe CFD may need multiple deformity correction or lengthening procedures during growth to reduce axial malalignment and leg length discrepancy. Various methods such as monolateral fixators, circular hexapod/Ilizarov fixators, and intramedullary lengthening nails have been developed. During limb lengthening, knee instability due to articular and soft-tissue deficiencies can result in knee subluxation and dislocation, a severe treatment-related complication.[1],[4],[7],[8]


  Case Report Top


A 15-year-old girl presented in 2019 with a shortening of the left limb. On examination, the left femur was short with a full range of movement of ipsilateral hip and knee. There was no history of hip dislocation, and grade 1 laxity was present on Lachman and Drawer tests. On teleroentgenogram of lower limbs, the left femur was shortened by 13 cm as compared to the right without any discrepancy of length in the leg compartment [Figure 1]. There was no other obvious congenital abnormality found in the radiograph. Diagnosis of Congenital Femoral Deficiency was established.[3] When she was 6 years old, it was carried a femoral lengthening with a mid-diaphyseal monofocal osteotomy using a monolateral external fixator. After 2 months of lengthening, a posterior subluxation of the knee was noted, so she removed the monolateral fixator [Figure 2]. Over the next few years, she presented several complications, namely fracture at the osteotomy site, failure of plate osteosynthesis and infection [Figure 3]. Eleven years later, she arrived at our hospital, and it was decided to make another attempt to correct the limb-length discrepancy and the femur deformity. We applied a knee spanning Ilizarov's ring for gradual correction. After 7 days of latent period, lengthening was started at the rate of 1 mm per day with 13 cm of length gained at 3 months [Figure 4]. The patient was allowed partial weight-bearing and walking with crutches during this period. The patient was also advised to do a range of motion (ROM) exercise of the hip. Femoral lengthening requires close follow-up and intensive rehabilitation in order to identify problems and maintain a functional extremity, respectively. Follow-up was every 2 weeks for radiographic and clinical assessment. Clinically, the patient was assessed for hip ROM, knee subluxation, nerve function, and pin sites. Radiographically, the distraction gap length, regenerate bone quality, limb alignment, and joint location were assessed.
Figure 1: Preoperative radiograph showing a 15-year-old girl with congenital femoral deficiency

Click here to view
Figure 2: Posterior subluxation of the knee during a femoral lengthening using a monolateral external fixator when she was 6-years-old

Click here to view
Figure 3: Complications following the removal of monolateral external fixator

Click here to view
Figure 4: Anteroposterior radiograph at 3 months following Ilizarov application

Click here to view



  Results Top


At 11 months following Ilizarov application, a complete correction was achieved, with both limbs of the same size and an improvement of the axial alignment of the left limb [Figure 5]. At this time, the circular fixator was removed. She is very satisfied with the surgery results, presenting a visual analog scale score 1 and a stable and pain-free lower limb, walking without external support. She has no clinical or analytical inflammatory signs.
Figure 5: Anteroposterior and lateral radiographs at 11-month follow-up

Click here to view



  Discussion Top


Almost all CFD can be assumed to have hypoplastic or absent cruciate ligaments with mild to moderate anteroposterior instability. Some also have mediolateral and torsional instability. Despite this, in most cases, the knee tracks normally preoperatively, and there is no need to perform a ligamentous reconstruction. Knee subluxation with lengthening is usually posterior and occurs due to conflict of force vectors at the hip and knee during lengthening. The dislocating forces are exerted by the tight periarticular tissues, mainly the iliotibial tract, which works against the anatomical bony deficiencies and, with its biarticular attachment, can cause knee dislocation.[9] Grill and Dungl reported on 37 patients with CFD, who were treated with femoral lengthening with the Ilizarov frame or monolateral lengthening device.[10] Complications and knee subluxation occurred in 21%. In order to prevent subluxation during lengthening, the knee joint should be bridged by the external fixator. The safest way of lengthening is, therefore, the preventive bridging of the knee with a circular frame. An accurately placed hinge at the center of rotation of the knee between the femoral and tibial frame allows safe lengthening and enables controlled mobilization of the knee joint. Monolateral fixators might give less stability, but with an adequate technique, the knee can be bridged as well. As mild knee subluxation can easily go unrecognized on X-rays, clinical examination and accurate radiographic analysis during bone lengthening are important to detect signs of subluxation of adjacent joints as early as possible. Consequences of subluxation and residual knee flexion deformity can be severe with functional leg length discrepancy, anterior knee pain, and inability to weight bear due to knee instability. Hence, before performing femoral lengthening in CFD, a complete assessment of the risk factors is necessary to avoid knee dislocation. The surgeon should maintain a high index of suspicion and be alert to recognize the symptoms and signs which indicate subluxation during lengthening.


  Conclusion Top


Knee joints of patients with CFD show highly variable grades of instability. Adequate surgical techniques, preventive measures, and early detection of signs of the subluxation can lead to good functional results in patients with CFD. Femur lengthening with a preventive bridging of the knee with an Ilizarov frame is safe and effective.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Sanpera I Jr., Fixsen JA, Sparks LT, Hill RA. Knee in congenital short femur. J Pediatr Orthop B 1995;4:159-63.  Back to cited text no. 1
    
2.
Kalamchi A, Cowell HR, Kim KI. Congenital deficiency of the femur. J Pediatr Orthop 1985;5:129-34.  Back to cited text no. 2
    
3.
Pappas AM. Congenital abnormalities of the femur and related lower extremity malformations: Classification and treatment. J Pediatr Orthop 1983;3:45-60.  Back to cited text no. 3
    
4.
Bowen JR, Kumar SJ, Orellana CA, Andreacchio A, Cardona JI. Factors leading to hip subluxation and dislocation in femoral lengthening of unilateral congenital short femur. J Pediatr Orthop 2001;21:354-9.  Back to cited text no. 4
    
5.
Renzi-Brivio L, Lavini F, de Bastiani G. Lengthening in the congenital short femur. Clin Orthop Relat Res 1990;Jan;(250):112-6.  Back to cited text no. 5
    
6.
Aston WJ, Calder PR, Baker D, Hartley J, Hill RA. Lengthening of the congenital short femur using the Ilizarov technique: A single-surgeon series. J Bone Joint Surg Br 2009;91:962-7.  Back to cited text no. 6
    
7.
Johansson E, Aparisi T. Missing cruciate ligament in congenital short femur. J Bone Joint Surg Am 1983;65:1109-15.  Back to cited text no. 7
    
8.
Paley D, Standard SC. Lengthening reconstruction surgery for congenital femoral deficiency. In: Rozbruch SR, Ilizarov S, editors. Limb Lengthening and Reconstruction Surgery. New York, London: Informa Healthcare; 2007. p. 393-428.  Back to cited text no. 8
    
9.
Fairclough J, Hayashi K, Toumi H, Lyons K, Bydder G, Phillips N, et al. The functional anatomy of the iliotibial band during flexion and extension of the knee: Implications for understanding iliotibial band syndrome. J Anat 2006;208:309-16.  Back to cited text no. 9
    
10.
Grill F, Dungl P. Lengthening for congenital short femur. Results of different methods. J Bone Joint Surg Br 1991;73:439-47.  Back to cited text no. 10
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Case Report
Results
Discussion
Conclusion
References
Article Figures

 Article Access Statistics
    Viewed276    
    Printed4    
    Emailed0    
    PDF Downloaded13    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]