Orthonotes
by the.bonestories
Menu
Stable: intact posteromedial buttress; Unstable: posteromedial comminution, reverse obliquity, subtrochanteric extension. Stable → DHS; Unstable → cephalomedullary nail/fixed-angle device.
10 AI-generated high-yield questions by our AI engine
Intertrochanteric (IT) femur fractures are extracapsular fractures occurring between the greater and lesser trochanters of the proximal femur. They are among the most common fractures in the elderly, representing approximately 45–50% of all hip fractures (alongside femoral neck fractures), with an annual incidence of approximately 200 per 100,000 population in patients over 65 years. Because they are extracapsular, blood supply to the femoral head is preserved and avascular necrosis is rare — the primary complications are non-union (uncommon with modern implants) and implant failure from poor fixation in osteoporotic bone. The Evans and Evans-Jensen classifications are the most clinically used systems for intertrochanteric fractures, grading stability and directly guiding implant selection.
| Evans Type | Description | Posteromedial Cortex | Stability | Jensen Modification | Implant |
|---|---|---|---|---|---|
| Type I (Undisplaced) | A two-part intertrochanteric fracture with NO displacement; the fracture line is complete but the fragments are not displaced; the posteromedial cortex is intact; the fracture is in a stable configuration without any component displacement | INTACT | STABLE — intact posteromedial cortex; the fracture can be impacted under load; excellent healing potential | Jensen Type 1 (two fragments, undisplaced) | Dynamic Hip Screw (DHS) — the sliding mechanism of the DHS allows controlled dynamic compression as the patient weight-bears; with intact medial cortex, the femoral head slides down the screw and impacts with the shaft → stable impacted fracture |
| Type II (Displaced stable) | A two-part intertrochanteric fracture with displacement; the fracture is displaced but can be reduced to a stable configuration; the posteromedial cortex is intact (or can be restored to bony contact after reduction); after reduction, the medial cortex provides bony support | INTACT OR RESTORABLE — can be brought back to cortical contact with reduction; the key is that after anatomical reduction, the medial cortex contacts and the fracture can be impacted | STABLE AFTER REDUCTION — once reduced, the intact or restored medial cortex provides stability; the DHS dynamic compression mechanism functions properly with cortical support | Jensen Type 2 (two fragments, displaced) | DHS — dynamic hip screw; the anatomical reduction ensures the medial cortex is in contact before screw insertion; the DHS provides dynamic compression along the femoral neck axis; anatomical reduction is critical to achieve the stable configuration |
| Type III (Unstable — posteromedial comminution) | A three-part fracture with POSTEROMEDIAL COMMINUTION — a separate lesser trochanter fragment (the posteromedial cortex) is detached, creating a third fragment; the medial cortex is disrupted; even after reduction, there is no medial bony support for the DHS to compress against | DISRUPTED — the lesser trochanter (which represents the posteromedial cortex) is detached as a separate fragment; there is no posteromedial bony contact after fracture reduction | UNSTABLE — without medial cortical support, the femoral head and neck tend to `ride up` on the DHS screw (the screw cuts out medially through the femoral head), or the shaft medialises under the condyle plate; DHS is biomechanically disadvantaged for Type III — however, many UK centres still use DHS for Type III with careful reduction technique and achieve adequate results | Jensen Type 3 (three fragments — lesser trochanter is the third fragment) | INTRAMEDULLARY (IM) hip nail (cephalomedullary nail — Gamma nail, PFNA, TFN-ADVANCED) is increasingly preferred for Evans Type III because: the nail provides medial support within the medullary canal; the cephalic screw or blade is placed in the femoral head with greater angular stability; the biomechanics do not rely on medial cortical support from the posteromedial wall; modern IM nails are more forgiving than DHS for unstable patterns |
| Type IV (Unstable — greater + lesser trochanter) | A four-part fracture with separate greater trochanter AND lesser trochanter fragments in addition to the main proximal and distal fragments; the posteromedial cortex is disrupted (lesser trochanter separated) AND the greater trochanter is also separated; the entire intertrochanteric region is comminuted | COMPLETELY DISRUPTED — both trochanters are separated; no posterolateral or posteromedial bony support | VERY UNSTABLE — four-part fracture with no inherent bony stability; the femoral head and neck are completely freed from the shaft by loss of both trochanters; high risk of varus collapse and screw cut-out | Jensen Type 5 (four-part — greater + lesser trochanter + two main fragments) | IM hip nail preferred; the angular stability of the cephalic blade/screw provides better resistance to varus collapse than DHS in this highly comminuted pattern; proximal femoral arthroplasty (endoprosthesis) may be considered for very elderly frail patients with severe osteoporosis |
| Reverse Oblique | A SPECIAL UNSTABLE PATTERN — the fracture line runs from SUPEROMEDIAL to INFEROLATERAL (the opposite obliquity to a stable intertrochanteric fracture); the fracture line is perpendicular to or reversed relative to the standard intertrochanteric pattern; this is NOT a standard Evans type but is a distinct and important unstable pattern; the shaft tends to displace MEDIALLY and the neck tends to displace laterally (the opposite deformity to standard IT fractures) | DISRUPTED in a specific way — the proximal fragment (neck + head) tends to abduct while the shaft medialises | HIGHLY UNSTABLE — the DHS is CONTRAINDICATED for reverse oblique fractures; when the DHS collapses (slides), the fracture DISPLACES rather than compressing (the sliding action of the DHS allows the shaft to medialise rather than the fracture to compress); this is the most important practical management distinction | NOT classified in Evans-Jensen but identified on X-ray by the reversed obliquity; Jensen also noted this as a distinct pattern | IM hip nail is the ONLY appropriate implant — the nail maintains the medullary alignment and prevents medial shaft displacement; DHS is contraindicated; this is a classic exam question: `which intertrochanteric fracture pattern is a contraindication to DHS? = Reverse oblique` |
| Implant | Indications | Contraindications | Key Advantage |
|---|---|---|---|
| Dynamic Hip Screw (DHS) | Evans Types I and II (stable intertrochanteric fractures); stable fracture patterns where medial cortical contact is achievable | REVERSE OBLIQUE (absolute contraindication); subtrochanteric extension; Evans Type III/IV (relative contraindication — many centres use DHS but IM nail is preferred); ipsilateral femoral shaft fracture | Well-studied; extramedullary; easier to remove; good outcomes for stable fractures; the lateral plate provides a moment arm that resists varus; the sliding mechanism allows dynamic compression and cortical impaction |
| IM Hip Nail (Gamma, PFNA, TFN) | Unstable intertrochanteric fractures (Evans III/IV); reverse oblique (mandatory); subtrochanteric fractures; any IT fracture where DHS is contraindicated; periprosthetic fractures; pathological fractures | Very medially displaced shaft (canal cannot be entered easily); severe ipsilateral femoral deformity; infection at nail entry site | Intramedullary load-sharing reduces bending moment on the implant; less reliance on medial cortical support; cephalic blade (PFNA) provides rotational stability in the femoral head; shorter operative time for experienced surgeons; allows earlier weight-bearing for unstable patterns |
10 AI-generated high-yield questions by our AI engine