Sliding Hip Screwplate in Pathologic Proximal Femur Fractures: Biopsy & Management Dilemmas
Key Takeaway
Biopsying hip metastases before Sliding Hip Screwplate (SHS) fixation involves a complex decision. Definitive tissue diagnosis is crucial for oncologic therapy, but surgical urgency, patient comorbidities, and known primary malignancy status influence timing. This balances diagnostic imperative with immediate fracture stabilization, patient safety, and optimal treatment sequencing.
A 65-year-old female presents with a displaced intertrochanteric hip fracture. She has no known history of malignancy. Her plain radiographs show a classic 31-A2.2 fracture pattern, but there is an area of radiolucency in the intertrochanteric region that appears atypical for simple osteoporosis. The patient is booked for theatre later today. What is your management plan regarding the diagnostic workup?
Candidate: I would be concerned about a pathologic fracture given the atypical radiolucency. I would postpone the surgery to perform a CT of the chest, abdomen, and pelvis to search for a primary malignancy and organize an image-guided core needle biopsy. I would not proceed with fixation until I have a tissue diagnosis.
A failing candidate often says "I would just go ahead and fix it because it's a hip fracture and time is bone," or alternatively, they forget the diagnostic sequence entirely. They fail to acknowledge the risk of treating a potential primary bone sarcoma as a simple metastatic lesion, which could lead to an inappropriate surgical approach (e.g., violating compartments that should have been left for a wide excision).
A high-scoring answer follows a structured, multidisciplinary approach: "In a patient with a suspected pathologic fracture and no known primary, a tissue diagnosis is mandatory prior to definitive fixation. I would 1) Proceed with urgent staging (CT CAP) to identify the primary, 2) Organize an image-guided core biopsy (usually via Interventional Radiology) to differentiate between metastasis, primary bone sarcoma, or benign aggressive pathology, and 3) Discuss the case in a Multidisciplinary Team (MDT) meeting. I would only deviate from this if the patient was haemodynamically unstable or the fracture required emergency stabilization, at which point I would consider an intraoperative frozen section or biopsy, though this is suboptimal compared to pre-operative image-guided sampling."
You have decided to proceed with a Sliding Hip Screw (SHS) for a stable intertrochanteric pathologic fracture. The patient has significant lytic destruction in the femoral head. How do you modify your technique to ensure the construct does not fail?
Candidate: I would use cement augmentation. I would perform a curettage of the tumor bed, inject PMMA cement into the cavity, and then insert the lag screw into the curing cement to improve purchase and reduce the risk of cut-out.
The candidate ignores the "biology vs. mechanics" trade-off. They fail to mention the importance of Tip-Apex Distance (TAD) despite the cement, or they focus only on the hardware and forget to mention that the cement essentially negates the "dynamic" collapsing nature of the DHS, turning it into a static construct.
The ideal answer integrates surgical principles with oncologic safety: "The primary modification is cement augmentation of the femoral head. I would perform an intraoperative curettage of the lytic lesion, then use a controlled technique to inject PMMA into the defect. I would ensure the lag screw is placed with a Tip-Apex Distance (TAD) < 25mm to minimize cut-out risk. I must acknowledge that using cement renders the DHS a static construct, eliminating the 'sliding' mechanism, so I would aim for an anatomical reduction prior to cementing. If the lysis were so extensive that the lateral wall was compromised, I would reconsider the implant choice and likely move to an intramedullary device to better bypass the diseased bone."
