Problem of Off screw in Trochanteric Fractures Nailing скачать в хорошем качестве

Problem of Off screw in Trochanteric Fractures Nailing

A non-central (eccentric) screw position in proximal femur nailing—especially the cephalic screw/blade used in intramedullary devices like PFNA, TFNA, Gamma nail—can compromise stability and increase risk of cut-out, non-union, or implant failure. Here are the main causes of a non-central screw in proximal femur nailing: 🔧 1. Improper Entry Point A too anterior or posterior entry leads to malalignment of the nail, affecting screw trajectory. Common when entry is off the tip of the greater trochanter or not aligned with the femoral canal. 📐 2. Incorrect Nail Positioning Malpositioned nail (valgus/varus tilt, rotational malalignment) alters the path of the cephalic screw. Medial or lateral malalignment shifts the screw off-center in the femoral head. 🔍 3. Poor Intraoperative Imaging Inadequate use of fluoroscopy or failure to get true AP and lateral views of the femoral head. Parallax errors can make the screw appear central when it is not. 🎯 4. Inaccurate Targeting Jig or Malfunction Targeting device may be: Incorrectly assembled Loose or bent Mismatched with nail model Leads to deviation in the drill guide axis and screw placement. 🔄 5. Failure to Adjust for Patient Anatomy Not accounting for anteversion, neck-shaft angle, or head size. Especially important in osteoporotic or deformed femurs, or after previous failed fixations. 🔩 6. Drift During Drilling Skiving of the drill bit on sclerotic bone or soft osteoporotic bone leads to off-track drilling. Also occurs if the guide sleeve is not firmly held against the lateral cortex. ⏱ 7. Haste or Lack of Experience Inadequate surgical planning or rushed screw insertion can result in a suboptimal trajectory. More common in early learning curve or unfamiliarity with the specific implant. 🛠 8. Implant Design Constraints Some systems offer limited screw trajectory options, especially if using a short nail or non-adjustable jig. 🔚 Consequences of Non-central Screw Risk of cut-out, especially in osteoporotic bone Rotational instability of head–neck fragment Non-union or implant failure ✅ Prevention Tips Use true orthogonal fluoroscopic views Verify entry point and nail alignment Double-check jig assembly and fit Ensure screw tip is center–center or inferior–center on AP/lateral Consider 3D navigation or intraoperative CT in complex cases IF NOTHINGS WORKS, USE MY TIP !!