Treatment of intertrochanteric fracture with the Gamma AP locking nail or by a compression hip screw - a randomised prospective trial

Abstract Objective When a hip screw needs to be changed, choosing between the conventional (C-type) and helical blade (H-type) types is difficult. In this biomechanical study, we compared these two screw types relative to the type of the initial screw used. Methods C- or H-type screws were inserted (leading screw) in three types of polyurethane bone models (Sawbone, Pacific Research Laboratories, Inc., Washington, USA: 130 × 180 × 40 mm) of different bone mineral densities (pounds per cubic feet [PCF] 5, 80 kg/m3; PCF 10, 160 kg/m3; and PCF 15, 240 kg/m3), and then successively or alternately inserted (following screw) after the leading screw removal. An original model (original C and H) of a leading screw without removal was created as a control. The strengths of resistance to pullout (PO) and rotational stress were measured. For each experimental condition, there were 30 experimental models. Results The original C screw was superior in PO strength, and the original H-type screw was superior in rotational strength. When the C- or H-type screw was the leading screw, using the C-type screw again as the following screw (C1-C2, H1-C2) showed the greatest resistance to PO, and using the H-type screw as the following screw (C1-H2, H1-H2) showed superior resistance to rotational strength. However, the rotational strength of the C2 screw decreased by more than 50% compared with that of the original C screw. Moreover, the PO and rotational strengths of the H2 screw decreased to less than 30% overall compared with those of the original H screw. Conclusion The H-type screw should be used for second-time screw insertion procedures in cases where it is difficult to choose between PO and rotational strengths.

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A study to assess proximal femoral nailing versus dynamic hip screw device in surgical management of intertrochanteric fractures: a comparative study

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20184719 ◽

2018 ◽

Vol 5 (1) ◽

pp. 23

Author(s):

E. S. Radhe Shyam ◽

K. Ashwin

Keyword(s):

Functional Outcome ◽

Intertrochanteric Fracture ◽

Trochanteric Fracture ◽

Dynamic Hip Screw ◽

Proximal Femoral Nail ◽

Technical Failure ◽

Intertrochanteric Fractures ◽

Femoral Nail ◽

Fracture Management ◽

Hip Screw

Background: The incidence of inter trochanteric fracture is expected to have doubled by 2040. Inter trochanteric fractures account for about 45% to 50% of all hip fractures in the elderly populationand out of these, near about 50% to 60% are classified as unstable intertrochanteric fractures. The goal of treatment is restoring mobility safely and efficiently, while minimizing the risk of medical complications and technical failure. This study as performed to assess functional outcome with dynamic hip screw and proximal femoral nail in intertrochanteric fracture management.Methods: It was prospective observational study done for a period of 1year from January 2016-January 2017 among patients who attended OPD or emergency department with intertrochanteric fracture. Two different implants were used dynamic hip screw (DHS) and proximal femoral nail (PFN).Results: Excellent results in functional outcome was more in case of PFN (66.6%) compared to DHS (50%). The type of trauma in DHS group was road traffic accident in 38.8%, domestic fall in 50% and others such as assault was in 11.1% while in PFN group intertrochanteric fracture was seen in 61.1% due to domestic fall.Conclusions: The functional outcome was more better with proximal femoral nail (PFN) compared to dynamic hip screw (DHS). Therefore, proximal femoral nail (PFN) should be preferred for management of intertrochanteric fractures.

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Measuring Intertrochanteric Fracture Stability with a Novel Strain-Sensing Sliding Hip Screw

10.1101/2020.09.04.20183251 ◽

2020 ◽

Author(s):

Nathan T. Carrington ◽

Paul W. Millhouse ◽

Caleb J. Behrend ◽

Thomas B. Pace ◽

Jeffrey N. Anker ◽

...

Keyword(s):

Finite Element ◽

Fracture Healing ◽

Bone Healing ◽

Revision Surgery ◽

Intertrochanteric Fracture ◽

Strain Sensing ◽

Sliding Hip Screw ◽

The Status ◽

Fracture Models ◽

Hip Screw

Background: Bone healing after internal fixation of intertrochanteric hip fractures is difficult to monitor with radiography, particularly with internal fixation implants such as the sliding hip screw (SHS). In this study, we evaluate a robust, user-friendly device to non-invasively determine the loading on the screw implant. This will allow clinicians to better monitor the status of bone healing and take preventative steps if complications occur. Methods: A novel strain-sensing sliding hip screw (SS-SHS) was designed and refined using a finite element model of a simple intertrochanteric fracture and a standard SHS implant. The SS-SHS houses an internally fixed indicator rod, whose position relative to the screw body can be viewed on plain film radiographs to measure screw bending. Screw bending was assessed in an intact femur and an unstable A1 intertrochanteric fracture using a finite element computational model and compared with experimental axial loading of a femoral Sawbones composite and human cadaveric femur specimens. Indicator rod position relative to the screw was visually tracked using plain radiographs at each load state. Results: The indicator rod was found to displace linearly in response to implant strain in the unstable fracture. This movement was consistently visible and measurable using radiography throughout loading cycles across the mechanical and cadaveric fracture models. Sensor movement was not detected in healed fracture models. The slope of the curve was approximately equal in the computations, composite and cadaveric models (0.08 μm/N, 1.0 μm/N, 0.08 μm/N, respectively). The noise level was approximately 25 N in the composite model and 63 N in the cadaveric specimen and this was sufficient to see 1/10th of body weight or more for an 80 kg patient which is likely good enough to track fracture healing. Conclusions: In current practice, clinicians must carefully monitor their patients for signs of implant failure after surgery. However, by the time signs of failure are apparent, it is often too late to avoid revision surgery. This device enables clinicians to quantitatively track fracture healing, and better communicate the process to the patient. Clinicians can also take preventive measures with at-risk patients before revision surgery is needed, thus reducing mortality risks. Clinical Relevance: By augmenting an existing SHS system with an indicator rod, crucial information on the status of fracture healing can be ascertained from follow-up radiographs already taken with no additional risk to the patient.

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