- See:
Insertion of Pins for Hip Frx:
- Indications for Closed Reduction and Fixation:
- indications for closed reduction and fixation:
- physiologically young patient: age < 65, working patient, good bone stock;
- demented elderly patient that requires total care;
- adequate
closed reduction w/ no frx comminution or femoral neck defects;
- patient should be aware that with an inadequate closed reduction, then an
open reduction or
hemiarthroplasty will be required;
- Radiographs:
-
accetable reduction parameters:
- Screw Insertion Technique:
-
technique of closed reduction:
-
positioning:
- supine position on the fracture table:
- this is the optimal position for fracture fixation, assuming that a satisfactory reduction is obtained;
- advantage is that it is easy to directed the guide pins into the femoral neck and head, since an AP and surgical lateral flourscopic view can be obtained
w/o having to move the patient's hip;
- disadvantage is that if the reduction slips, it can be difficult to re-reduce the hip while the hip is in the extended position on the fracture table;
- lateral position:
- main advantage is that the fracture table is not required and that hip can be re-reduced if the initial reduction is lost;
- main disadvantage is that the frx reduction may slip as the hip is flexed and externally rotated (for the frog leg lateral view);
-
configuration and number of screws::
-
guide pin insertion point and angle of insertion:
-
depth of guide pin placement:
- under flouroscopy, guide-pin is drilled into place along medial cortex of femoral neck & into head to within 5 mm of subchondral bone;
- cannulated drill is then placed over each pin and drilling carried out to depth of 5 to 10 mm short of the tip of the pin to keep guide wire from coming out;
- length of screws to be implanted is determined by direct measurement of guide pins, which have been inserted just shy of subchondral bone;
- references:
-
Articular penetration is more likely in Garden-I fractures of the hip.
-
screw selection and insertion:
- in very dense bone, a tap should be utilized into femoral head, but generally is only necessary in lateral cortex;
- in most systems there are two screw-thread lengths availabe: short and medium;
- it is essential that all of the screw threads are past the frx site (inorder to achieve compression), and therefore the short threaded screws will often be required;
- screws are then inserted and retightened after any traction that has been placed on the limb has been released;
- inferior screw is placed first, followed by the superior screws;
- guide wire should be removed after screw has passed across fracture to prevent advancing the guide wire into the hip joint;
- screws are tightened simultaneously, to apply uniform compression across frx & to avoid tipping of femoral head into varus angulation;
-
impaction of frx:
- when bone is dense, impaction of frx can be performed after traction is released by applying mallet blows to a
broad bone tamp placed on lateral surface of the proximal femur adjacent to screws;
- following such impaction, the screws should be retightened in hopes of maintaining interfragmentary compression;
-
anterior capsulotomy:
- some surgeons feel that these patients require emergent reduction and pinning along with
capsulotomy (to avoid hematoma and
and increase in intra-articular pressure);
- Post Operative Care:
-
forces acting on the hip joint:
- as noted by KJ Koval et al 1998, elderly patients who are allowed to bear wt as tolerated, will voluntarily limit loading of the injured limb;
- references:
- Postoperative weight bearing after a fracture of the femoral neck or an intertrochanteric fracture.
KJ Koval et al. JBJS. Vol 80-A. No 3. March 1998. p 352.
- Complications:
-
avascular necrosis:
- as pointed out by S.E. Asnis and L.W. Sgaglione (JBJS 1994), patients who develop AVN following hip frxs may continue to maintain high level of function;
-
non-union:
-
subtrochanteric fracture:
- if guide pins are inserted into the lateral cortex at a point below the lesser trochanter a stress riser will be created, risking frx;
- holes at this location have been assoc w/ 20 % prevalence of subtrochanteric frx;
- reference:
Subtrochanteric fracture after cannulated screw fixation of femoral neck fractures: a report of four cases.
Internal fixation of femoral neck fractures. A comparative biomechanical study of Knowles pins and 6.5-mm cancellous screws.
Intracapsular Fractures of the Femoral Neck. Results of Cannulated Screw Fixation.
S.E. Asnis MD and L.W. Sgaglione DrPH JBJS. Vol 76-A No 12, Dec 1994. p 1793-1803.
Screw positions in femoral neck fractures. Comparison of two different screw positions in cadavers.
A comparison of femoral neck fixation with the reconstruction nail versus cancellous screws in anatomic specimens.
Crossed pins vs parallel pins in the treatment of femoral neck fractures.
Fixation of displaced femoral neck fractures. A comparison between sliding screw plate and four cancellous bone screws.
Intracapsular fractures of the neck of femur. Parallel or crossed garden screws?.
Subcapital fractures of the femur. A prospective review.
Intracapsular fractures of the femoral neck. Results of cannulated screw fixation.
Subchondral screw fixation for femoral neck frx
Femoral neck fractures in skeletally mature patients, fifty years old or less. SM Tooke and KJ Favero. JBJS. Vol 67-A. 1985 p 1255-1260.
Internal Fixation Compared with Arthroplasty for Displaced Fractures of the Femoral Neck. A Meta-Analysis.
The complications of displaced intracapsular fractures of the hip. The effect of screw positioning and angulation on fracture healing.
Comparison of Internal Fixation with THR for Displaced Femoral Neck Frx Randomized, Controlled Trial Performed at 4 Years.
Bone grafting in femoral neck fractures: results in 28 cases operated on with multiple pinning and cancellous bone grafting.
Femoral neck fracture fixation with hook-pins. 2-year results and learning curve in 626 prospective cases.
