Evaluation of Risk of Lag Screw Cut Out in Unstable
Muhammad Khan Pahore, Muhammad Ayub Laghari, Asad Ullah Makhdoom,Mehtab Pirwani, Irshad Ahmed Bhutto, Prof. Abdul Rehman Shaikh.
OBJECT: To evaluate the risk of lag screw cut out in unstable intertrochanteric fractures.
MATERIAL & METHODS: This study was conducted in the Department of Orthopedic Surgery
and Traumatology (DOST) Liaquat University of Medical & Health sciences Jamshoro from
January 2006 to December 2009. Unstable intertrochanteric fractures type A2 & A3 of AO
classification fixed with DHS in stable (anatomic & wayn county) reduction, were included in
study. All patients were assessed on six months follow up x-rays for cut out failure in different
positions for placement of screw in femoral head. For placement of screw, femoral head was
divided in 9 columns/zones on antero-posterior & lateral plane x-rays.
RESULTS: Out of total 66 study subjects 45 (68.1%) were males and 21 (31.8%) were females, 56
(84.8%) were of A2 and 10 (15.2%) of A3 type. Mean age was 65.41 years. Forty (60.6%) patients
were fixed in anatomical reduction and 26 (39.3%) in wayn county reduction. The screw placement
was 24 (36.3%) in central central, 9 (13.6%) in central inferior, 17 (25.7%) in posteriorinferior
and 16 (24.2%) in remaining off central (unsatisfactory) zones. The cut out was in 2 patients
( 8.3% ) in central-central , 0% in central inferior position , 3 patients (17.6%) in posterior
inferior and 4 patients (25%) in remaining off central zones (all cut out were in superior zones of
CONCLUSION We conclude that placement of lag screw in inferior on AP and central on lateral
view in femoral head gives excellent results after achieving stable reduction, having maximum
bone to plow for cut out. But it is difficult and time consuming so if it is aimed in lower half on
AP and central on lateral view in femoral head it will give better results.
Key words: lag screw; femoral head; cut out failure; unstable intertrochanteric fractures;