Neurobionplus
Home About Journal AHEAD OF PRINT Current Issue Back Issues Instructions Submission Search Subscribe Blog    
Login 

Users Online: 4146 
Print this page  Email this page Small font sizeDefault font sizeIncrease font size 
 


 
 Table of Contents    
LETTER TO EDITOR  
Year : 2011  |  Volume : 45  |  Issue : 6  |  Page : 583-584
Femoral tunnel-interference screw divergence in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: A comparison of two techniques


1 Department of Orthopedic Surgery, Lady Hardinge Medical College, New Delhi, India
2 Department of Orthopedic Surgery, Maulana Azad Medical College & Associated Lok Nayak Hospital, New Delhi, India

Click here for correspondence address and email

Date of Web Publication4-Nov-2011
 

How to cite this article:
Sabat D, Arora S. Femoral tunnel-interference screw divergence in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: A comparison of two techniques. Indian J Orthop 2011;45:583-4

How to cite this URL:
Sabat D, Arora S. Femoral tunnel-interference screw divergence in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: A comparison of two techniques. Indian J Orthop [serial online] 2011 [cited 2019 Aug 18];45:583-4. Available from: http://www.ijoonline.com/text.asp?2011/45/6/583/87145
Sir,

We read the article "Femoral tunnel-interference screw divergence in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: A comparison of two techniques" [1] with great interest.

We would like to congratulate the authors for excellent work. This is a randomized controlled study (level II); but a prior power analysis has not been done. The exclusion criteria for patient's selection and the demographic comparison of the two groups are also missing. Interestingly, the authors have evaluated 82 cases those were selected consecutively and randomized over 4 years; but no drop out or loss to follow-up has been reported. The authors have also not mentioned any complication or failure of treatment. However, [Figure 1] [1] clearly shows an anteriorly placed tunnel on the femoral side, the complication which has been overlooked.

In the operative procedure; the authors state that the guide wire for femoral tunnel was kept 7 mm anterior to the posterior edge of lateral femoral condyle using a femoral offset of 6 mm. How this can be made possible? Again the femoral tunnel was dilated till 9 mm. Using a 6-mm femoral offset is risky as there would be only 1.5 mm of bone behind the tunnel after reaming with 9-mm reamer. At least 2 mm of bone behind the tunnel is recommended to prevent blow out. The authors should also mention the size and make of the screws along with the manufacturer details as in all cases the bone plug and the tunnel diameter was kept constant.

The statistical test used to compare Lysholm's score is also not mentioned. Statistical analysis of the results has not been mentioned in terms of calculated P-value for Lysholm's score and k-value should have been mentioned for intraobserver variation. Merely stating a significant difference was found or not, may not make a reader wise all the times.

All the patients were divided into four groups according to the screw divergence angle; but the clinical data was not analyzed within these groups using Lysholm's score.

There is discrepancy of data in the tables. In [Table 3], [1] group 2 shows grade 4 divergence in two cases with IKDC grade A and B in one case each. But [Table 2] [1] shows only one case with grade 4 divergence. The version of IKDC score used is missing. Since the IKDC grade has been mentioned in the results, the authors must have the data of laxity measurement as this is an integral part of IKDC score. This data of clinical laxity may have been analyzed to find any correlation with screw divergence.

The authors claim this study to be the first study comparing the two methods of screw insertion. However, we point out few studies for authors' appraisal which have probably been missed from the discussion. Hackl et al.,[2] (2000) reported the use of a central portal to decrease screw divergence. In a cadaveric study, they concluded that using a central portal and flexing the knee by 35-40° more, the screw divergence can be minimized in both sagittal and coronal planes. Dworsky et al.,[3] in a clinical study of 72 cases, concluded that screw divergence of <30° does not seem to have a significant effect on the clinical outcome if the fixation strength at time of operation is tested and found to be adequate. These important issues are missing from the discussion.

Omission of coronal plane screw divergence (in the antero-posterior view of the knee) is a big drawback of the study. The factor weakens the study to a great extent. The authors explain that the tunnel outline is not always visible on postoperative AP radiographs. It is true only for the immediate postoperative radiographs. But the tunnel outline becomes visible afterwards in the follow-up in 3-6 months of surgery due to development of a sclerotic zone at the perimeter of the tunnel. Although some tunnel widening may have set in, the axis of the tunnel and the screw may easily be measured.

Lastly, the current trend is anatomical ACL reconstruction, in which the femoral tunnel is made at the footprint. So a low or accessory anteromedial (AM) portal is used to make the femoral tunnel preparation and fixation. This method obviates the problem of screw divergence. [4] Also significantly earlier return to run, greater range of motion, Lachman test values and KT-1000 arthrometer measurements in 1-2 year follow-up have been reported with the AM portal technique. [5]

 
   References Top

1.Pandey V, Acharya K, Rao S, Rao S. Femoral tunnel-interference screw divergence in anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: A comparison of two techniques. Indian J Orthop 2011;45:255-60.  Back to cited text no. 1
[PUBMED]  Medknow Journal  
2.Hackl W, Benedetto KP, Hoser C, Künzel KH, Fink C. Is screw divergence in femoral bone-tendon-bone graft fixation avoidable in anterior cruciate ligament reconstruction using a single-incision technique? A radiographically controlled cadaver study. Arthroscopy 2000;16:640-7.  Back to cited text no. 2
    
3.Dworsky BD, Jewell BF, Bach BR Jr. Interference screw divergence in endoscopic anterior cruciate ligament reconstruction. Arthroscopy 1996;12:45-9.  Back to cited text no. 3
[PUBMED]    
4.Harner CD, Honkamp NJ, Ranawat AS. Anteromedial portal technique for creating the anterior cruciate ligament femoral tunnel. Arthroscopy 2008;24:113-5.  Back to cited text no. 4
[PUBMED]    
5.Alentorn-Geli E, Lajara F, Samitier G, Cugat R. The transtibial versus the anteromedial portal technique in the arthroscopic bone-patellar tendon-bone anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2010;18:1013-37.  Back to cited text no. 5
[PUBMED]  [FULLTEXT]  

Top
Correspondence Address:
Dhananjaya Sabat
Department of Orthopedic Surgery, Lady Hardinge Medical College, New Delhi-110 001
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0019-5413.87145

Rights and Permissions



This article has been cited by
1 Authorsę reply
Pandey, V., Acharya, K.V., Rao, S.K., Rao, S.P.
Indian Journal of Orthopaedics. 2011; 45(6): 584-585
[Pubmed]



 

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


 
    References
 

 Article Access Statistics
    Viewed1154    
    Printed55    
    Emailed0    
    PDF Downloaded88    
    Comments [Add]    
    Cited by others 1    

Recommend this journal