of the Hip and Femoral Shaft

Fig. 22.1

(a) AP x-ray of a posterior dislocation of the left hip with fracture of the posterior wall. (b) Postreduction x-rays show concentric reduction of femoral head, but the posterior wall fragment remains displaced. Further management depends on clinical stability

A hip that re-dislocates at 45° flexion or less usually indicates a sizeable fracture of either the posterior wall or femoral head. Large posterior wall fragments should be fixed (see Chap. 21). Large femoral head fragments—from the weight-bearing area, between 10 and 2 o’clock—should be fixed, or otherwise excised, along with the ligamentum teres. Ideal fixation is with two lag screws starting from the femoral neck. For small fragments, a screw head can be countersunk below the articular surface or small threaded K-wires cut flush with the articular surface. The hip is reduced and assessed for stability and the posterior capsule repaired. If stable a non-weight-bearing gait with range of motion starts early and continues for 6–8 weeks. In selected cases, 2–3 weeks of traction may be beneficial. In theory, surgery is indicated for an unstable hip with more than 2–3 mm of residual displacement of the posterior wall or dome fragment. But this is only true if appropriate resources are available; otherwise, the patient is best treated conservatively as outlined above.

The incidence of AVN increases with the duration of the dislocation, but the correlation with time is inconstant [1]. If the dislocation is relatively fresh, the patient usually presents with only mild discomfort at rest, pain on passive motion, shortening, and inability to bear weight. AVN may or may not be present or visible on x-rays at this time.

Potential benefits of regaining length and the ability for painless ambulation by an open reduction must be weighed against risks of creating or exacerbating AVN or neurovascular injury. Open reduction is not indicated if the head is already deformed.

For long-standing dislocations with severe shortening, and no evidence of AVN, it is safer to put the patient in skeletal traction for 2 weeks and evaluate the position of the head on pelvis x-ray. Or, perform a complete hip release, and place the patient in straight leg skeletal traction, with the added risks of a second anesthetic or infection. A successful reduction may still lead to AVN or a painful, stiff hip. Unless arthroplasty is available, fusion and Girdlestone excisional arthroplasty (see Chap. 41) are the only other surgical options. Patients seen after 6 months have adapted to a large extent and should be left alone (Fig. 22.2).

../images/270913_2_En_22_Chapter/270913_2_En_22_Fig2_HTML.png — Fig. 22.2

Chronic obturator dislocation with neoacetabulum. The patient walked with an abduction contracture and relative shortening, but no pain

Anterior Hip Dislocations

These are much less common than posterior dislocations (Fig. 22.3). The hip is usually slightly flexed, abducted, and externally rotated, with the femoral head often palpable in the groin. Closed reduction is by traction in the axis of the dislocation, followed by internal rotation and extension. The hip should be examined for stability in extension and if unstable needs treatment in flexion. Joint incongruity or retained fragments are treated as described above for posterior dislocations.

../images/270913_2_En_22_Chapter/270913_2_En_22_Fig3_HTML.png — Fig. 22.3

(a) The shortened, externally rotated right leg in an anterior dislocation of the hip caused when the farmer slipped and hyperextended his right leg 5 days before. (b) Pre- and postreduction x-rays of the pelvis

Stable hips can be placed in skin traction for comfort for a few days, avoiding external rotation. Instability in extension is usually due to an associated fracture, with or without fragment entrapment. An open reduction through an anterior approach is indicated, but fixing a fractured anterior wall or column is technically more demanding than the posterior wall, sometimes requiring a separate ilioinguinal approach.

Fractures of the Proximal Femur

The incidence of these fractures in austere environments is increasing as populations age [2]. They are challenging and remain “unsolved fractures” due to lack of fluoroscopy and fracture tables, delayed presentation, poor implants, and few viable alternatives such as prosthetic replacement [3]. Painful nonunions condemn the patient to use walking aids or a wheelchair.

Femoral Neck Fractures

Intracapsular fractures are associated with varying degrees of compromise to the femoral head circulation. Valgus impaction or undisplaced fractures (Garden 1 and 2) have a better prognosis of healing and less incidence of AVN than fractures with varus or total displacement (Garden 3 and 4). Nonoperative management of fractures impacted in valgus can be considered, but all other fresh fractures are candidates for internal fixation, particularly in younger patients.

If fluoroscopy and a fracture table are available, percutaneous compression screw fixation is routine. With fluoroscopy but no fracture table, percutaneous treatment is still possible with a radiolucent table and good assistants by slightly elevating the patient’s involved buttock on a cushion so that the femoral neck is roughly parallel to the ground. One scrubbed assistant provides traction on the leg, while an unscrubbed assistant gives countertraction over the contralateral shoulder via a folded sheet passed under the patient, between the legs and over the perineum. The difficulty with this technique is the lack of lateral projection, requiring the surgeon to go by feel along the anterior neck to determine reduction and implant placement.

Regular short-threaded 6.5-mm cancellous screws can be used when cannulated screws are unavailable. Over-drill the lateral cortex with a 4.5-mm drill bit, and advance the blunt tip of a K-wire in a push-pull fashion. This maximizes the tactile information as one crosses the fracture and prevents neck perforation. Positioning and depth can be assessed on a through-table AP view. A second or third K-wire should be inserted parallel to the first, replacing the wires one by one with screws. Even divergent screws will provide some compression. Fluoroscopy will confirm that the construct moves as a unit, supplemented with a partial frog-leg position or a portable lateral.

When no intraoperative x-rays are available or the fracture is so old that it cannot be reduced closely, the only surgical option is an open reduction through an anterior approach. The anterior neck is rarely comminuted, making the reduction assessable both visually and palpably. A 3.2-mm drill bit can be advanced blindly in the axis of the neck, and parallel to the floor, in a push-pull fashion as described above to a depth as measured on the pre-op x-ray. A second drill bit of equal length is helpful in determining the screw length and is used to drill a second path parallel to the first. The screw is inserted with the first drill bit still in place to prevent the head from spinning. The two screws are compressed, and the construct is tested for stability in movement with no adventitious grinding sensation. A third screw is an option, but the risks of misplacement are higher with this blind technique.

Established painful nonunions without AVN and head deformity may benefit from open reduction, curettage, and compressive fixation, with or without a Judet/Myers procedure (see Chap. 41) [4]. An alternative, especially for neck fractures presenting after 10 days at which point an open reduction may cause more harm than good, is an extra-articular valgus osteotomy at or below the level of the lesser trochanter, to avoid the risk of iatrogenic AVN. Our choice is a 10–20° valgus correction that when fixed with a 135°-degree blade plate, a sliding hip screw, a cephalic nail, or regular short-threaded screws should allow compression at the nonunion and the osteotomy with weight bearing. Temporarily pinning the head to the acetabulum before reaming and tapping avoids spinning the proximal fragment (https://www.youtube.com/watch?v=TAuZTqAAt9g).

When available, hemiarthroplasty is the treatment of choice for nonunion. If degenerative changes in the acetabulum are already present, it should be reamed to subchondral bone and to the size of the selected prosthetic head. When head sizes are limited, reaming to the next size up is a better alternative than using a too small head. Total hip arthroplasty is rarely available and affordable.

Many elderly, low-demand patients with months-old fractures do well with the use of a walking aid, and the western surgeon needs to resist his or her training reflexes and avoid surgery based on x-rays and ingrained habits rather than the patient’s needs.

Intertrochanteric (Pertrochanteric) Fractures

These fractures are extracapsular and less likely to develop AVN. They are common insufficiency fractures in the elderly, but significant energy is required for a similar fracture in young adult bone. Patients present with pain, shortening, and external rotation of the limb. Nonoperative management with skeletal traction is usually successful in treating this fracture but requires 6–8 weeks of bed rest before patients can be mobilized without significant discomfort and often leads to malunion with shortening, varus, and rotation. Complications related to bed rest may require earlier mobilization at 3–4 weeks, with an increased incidence of malunion or nonunion. It is not easy to find the delicate balance between what is best for the fracture and best for the patient. Patients who present late may benefit from a shoe lift, as most patients accommodate well to the malunion.

Where fluoroscopy, fracture table, and appropriate implants are available, treatment is closed reduction and internal fixation with a sliding hip screw device or a cephalic nail. Cephalic nails are mechanically better for unstable fractures—those with posterior-medial comminution. Nails with larger proximal diameters risk added comminution at the entry site, making trochanteric entries preferred to piriformis fossa entry.

The proximal locking screws of an antegrade SIGN nail can engage the head and neck fragment of more stable intertrochanteric fractures with the added stability of directed screws running up into the head and neck (Fig. 22.4). SIGN’s hip fracture implant and instruments increase the precision of screw placement and give the construct added robustness (Fig. 22.5). (SIGN Hip Construct SHC System Operative Guide PDF available from SIGN Fracture Care International https://signfracturecare.org/).