How to Perform Hip Hemiarthroplasty Using the Hardinge Approach

Patient Positioning, Anesthesia, and Preparation

• The patient is positioned in a lateral decubitus position with the affected hip facing upward.

• The pelvis is stabilized in a neutral position, avoiding tilting, using supports anteriorly and posteriorly.

• After hip dislocation, the lower leg is placed anteriorly in a sterile bag, requiring space in front of the patient.

• Either general or spinal anesthesia can be used.

Landmarks and Incision Site

To be able to dislocate the hip anteriorly, broach the femur, and implant the components via the Hardinge approach, a correctly placed skin incision is necessary.

The skin incision is placed by the location of the greater trochanter.

1. The anterior edge, tip, and posterior edge of the greater trochanter and the femoral shaft are palpated and marked.

2. The anterior superior iliac spine, ASIS, is palpated and marked for overall orientation of the pelvic position.

3. The incision is planned at the midline of the lateral surface of the greater trochanter or slightly anterior in the AP direction.
   
   The hip is later dislocated anteriorly by external rotation. The incision must be positioned to allow this. If placed too posteriorly, reaching the anterior structures becomes difficult.
   
   

4. The incision begins approximately 5 cm proximal to the trochanter tip to allow hip dislocation and adequate working space for instruments. However, extending further proximally risks injury to the superior gluteal nerve coursing under the gluteus medius muscle.
   
   The incision extends distally in line with the femoral shaft, ending approximately 10 cm inferior to the trochanter tip to allow adequate distal exposure for femoral preparation.
   
   

Skin Incision and Advancing to Fascia Lata

1. The skin is incised with a scalpel according to the planned line, advancing through the skin layer into the subcutaneous tissue. There are no critical structures directly beneath the skin at this level.

2. Hemostasis is secured with diathermy.

3. Subcutaneous tissue is incised with a scalpel or diathermy, and retractors are placed to improve visibility if needed.

4. In cases with thicker subcutaneous tissue, the greater trochanter can be palpated to maintain orientation and intended direction toward its lateral surface.

5. With the fascia visible throughout the length of the incision, the subcutaneous layer may be slightly mobilized from the fascial surface to facilitate later fascial closure.

Opening the Fascia and Placing the Charnley Retractor

1. The greater trochanter is palpated to confirm the fascial incision site on its lateral surface, approximately midline or slightly anterior in the AP direction.

2. The fascia is incised with a scalpel or electrocautery to create an initial opening.

3. The gluteus maximus muscle fibers are visible posteriorly beneath the fascia and can be bluntly separated.

4. The fascia opening is extended distally and proximally with scissors in line with the skin incision to match the incision’s length.

5. Underlying muscle fibers are separated bluntly, advancing toward the lateral greater trochanter. Typically, some bursal tissue is present in this layer.

6. When the fascial opening is complete and the lateral part of the greater trochanter is visible, a Charnley retractor is placed at mid-wound level.
   
   The sciatic nerve runs deep and posterior in the modified Hardinge approach and is typically not endangered. Nevertheless, the posterior retractor blade is kept superficial, at the fascial level.
   
   

7. The lateral surface of the greater trochanter is now exposed. The gluteus medius tendon attachment is visible beneath the overlying bursal tissue.

Detaching the Gluteus Medius and Minimus

The gluteus medius and minimus are partially released from the anterior trochanter to expose the joint capsule. The posterior muscle attachment is preserved for abductor function. Proximal dissection is limited to 3–5 cm above the trochanter to protect the superior gluteal nerve.

1. The bursa overlying the muscle is opened first to expose the gluteus medius tendon beneath.

2. The greater trochanter is palpated to define the incision site of the gluteus medius tendon insertion: at the midline or slightly anterior of the greater trochanter lateral surface.

3. Incising down to bone level from the tip of trochanter to the vastus lateralis insertion level.
   
   The anterior gluteus medius tendon is elevated as a flap along the trochanter surface.
   
   

4. External rotation of the hip allows the medius flap to be lifted anteriorly, improving exposure.

5. The retractor is repositioned to allow the incision to continue superiorly toward the acetabulum.

6. Proximal to the trochanter tip, the gluteus medius muscle is split bluntly in line with its fibers. The dissection must not extend too far proximally, 3–5 cm, to preserve the superior gluteal nerve running between the gluteus medius and minimus.

7. The Charnley retractor can be placed deeper to hold the detached medius tendon aside. The gluteus minimus is released from its femoral insertion, in line with the medius release.

8. With both muscles detached, a retractor can be set to hold the minimus aside. The joint capsule is exposed.

Opening the Joint Capsule

The joint capsule, including its thick integrated anterior ligaments, is opened to expose the femoral neck and allow dislocation.

1. A T-shaped incision extending along the anterior greater trochanter edge and longitudinally toward the acetabulum provides adequate access.

2. The capsule is incised along the edge of the greater trochanter using a scalpel or electrocautery. This forms the horizontal limb of the T-incision.

3. A longitudinal cut extends toward the acetabulum, forming the vertical limb of the T. The incision can be extended to the acetabular labrum, which should be preserved.

4. The femoral neck is visible underneath the capsule layer.

Dislocating the Hip

With displaced fractures, direct dislocation of the neck and head might not be possible. In those cases, an initial neck cut can be made prior to dislocation to remove the head. With impacted fractures, or in an intact case like this, dislocation of the head and neck together can be done at this stage.

1. Flexion, external rotation, and traction are applied to the femur, dislocating the head from the acetabulum and bringing the tibia toward the floor. The lower leg is then positioned into a sterile bag.

2. Retractors are placed above and below the femoral neck for exposing the neck for resection and for soft tissue protection during sawing. They are introduced along the bone, staying inside the capsule, to avoid damaging the deeper structures.

Resecting the Femoral Neck

The goal is to resect the femoral neck at the pre-planned level, typically referenced to the lesser trochanter. This determines prosthesis depth and directly affects leg length and offset.

1. Leg position is confirmed with the tibia toward the floor. Retractors are in place to protect the medial soft tissues during sawing.

2. The resection level follows preoperative templating. The greater trochanter tip is palpated to identify the gluteus medius attachment. This must not be violated.

3. A firm two-handed grip controls the saw. Full power is applied before contacting bone. The resection angle should be perpendicular to the femoral neck axis, avoiding additional tilting of the saw blade.

4. The superior portion is cut first. The saw is then redirected to the inferior side. On the medial side, the saw tip must not advance too deep. A blunt retractor protects the soft tissues.

5. The cut can be completed with an osteotome following the saw plane, without leveraging against the greater trochanter.

6. Bone forceps are applied to grasp the head. Any remaining capsule attachments are freed to detach the head completely.

7. Lastly, the head diameter is measured to guide the prosthetic head sizing.

Opening the Femoral Canal

The goal is to establish lateral entry to the femoral canal, setting the correct orientation for broaching and preventing varus malpositioning of the stem.

1. Leg position is checked. The tibia pointing toward the floor provides a constant reference for hip rotation.

2. A curved retractor is placed under the femur to elevate it, improving access for canal preparation.

3. The junction between the neck and greater trochanter is cleared of remaining tissue to expose the lateral border of the resection level, which will be used as a landmark for the entry point.

4. The box osteotome is positioned at the lateral border of the resection. The goal is to establish an entry point laterally that allows neutral stem alignment. A medial canal entry site makes varus alignment more likely, which can result in an undersized stem and early loosening.

5. The canal is opened with controlled mallet strikes, directed along the axis of the femur, just deep enough to create a passage.

6. With the entry established, a canal finder is inserted laterally and advanced in line with the shaft without levering against bone.

7. The area is cleared of debris. With the canal open and lateral entry established, broaching can proceed.

Broaching the Canal

The goal is to shape the canal for secure stem fixation with correct depth, alignment, and rotation.

Depending on prosthesis design, typical broaching-related risks are the stem ending up too high or in varus. When broaching, the implant-specific manufacturer’s instructions should be followed.

1. Leg position is confirmed and the correct side rasp is selected, starting with the smallest size.

2. The rasp is inserted laterally and kept against the greater trochanter along the femoral axis.
   
   Starting the broaching medially makes varus malposition and an undersized stem more likely.
   
   

3. This implant system has built-in anteversion, meaning that the correct neck anteversion is achieved by aligning the rasp with the calcar. Some systems may require anteversion to be estimated and set intraoperatively.

4. Working the rasp back and forth against the lateral wall maintains lateral positioning and widens the proximal canal laterally.

5. Controlled mallet strikes are used when advancing the rasp deeper. Excessive force can cause fractures, especially in osteoporotic bone.

6. The rasp is advanced toward the resection level, then withdrawn. This continues until the rasp sits at the intended depth.

7. When the rasp reaches the wanted depth but still rotates in the canal, the next size is selected.
   
   The process is repeated with each larger rasp until rotational stability is achieved at the intended depth, confirmed against the templated stem size.
   
   

8. The final broach size will be rotationally stable on the planned depth level. The sound of hitting the broach with a mallet will also change when it is in contact with the cortical bone. The handle is removed.

9. With this model, the actual prosthesis stem will be one size smaller to allow space for cement.

10. The cut surface is cleaned, and the calcar area is inspected for fissures. The collar of the prosthesis rests here, transferring load directly to bone. If fractured, this support is lost and stem subsidence may occur.

11. Lastly, the resection surface is reamed to achieve an even plane for the collar. The reamer is placed over the broach and rotated while maintaining the resection angle. Excessive pressure is avoided in osteoporotic bone. A freely swiveling reamer confirms the surface is prepared.

12. The canal is now shaped for secure stem fixation: the rasp is stable at the resection level, laterally positioned to avoid varus, and aligned with the calcar for correct anteversion. The calcar appears intact with no fractures identified.

Trialing the Components

The goal of trialing is to verify that the selected prosthetic components restore optimal hip function before final implantation. This includes confirming appropriate leg length and offset, assessing stability through full range of motion, and ensuring proper soft tissue tension to prevent both dislocation and impingement.

1. According to the preoperative plan, a trial neck with the predetermined angle and size is selected and inserted onto the trial stem.

2. The trial neck height relative to the trochanter tip level can be assessed at this point.
   
   This should correspond to the planned center of rotation level relative to the trochanter tip in the preoperative templating.
   
   

3. A trial head is selected based on the measurement of the resected femoral head and inserted onto the trial neck.

4. Before reduction, the acetabulum is inspected with a finger to ensure no bone fragments or tissue have fallen into it, interfering with the reduction.

5. The retractor is removed to allow access for hip reduction. A clamp is applied to hold the anterior capsule edge clear, preventing tissue interposition during reduction.

6. The hip is reduced by guiding the prosthetic head into the acetabulum with the head impactor while the assistant applies longitudinal traction and internal rotation to the femur.

7. A systematic assessment now verifies leg length and offset restoration through soft tissue tension testing and muscle alignment, along with stability and range of motion.
   
   The hip is taken through extension and flexion to confirm adequate

   range of motion without restriction.
   
   Internal rotation is tested to confirm the hip does not dislocate posteriorly.
   
   External rotation is tested to confirm anterior stability.
   
   

8. Soft tissue tension is assessed with lateral traction or pull. The hip should demonstrate slight movement in flexion and minimal movement in extension. Excessive tightness can restrict movement and predispose to dislocation, while excessive laxity risks instability.

9. An additional verification method is to assess whether the gluteus medius tendon aligns properly with its anatomical position on the greater trochanter, without significant mismatch. Proper alignment indicates appropriate offset and component sizing.

10. With the trial components verified as satisfactory, the hip is dislocated with external rotation and longitudinal traction. The trial head, neck, and stem are removed.

11. Following trial reduction, the calcar region is inspected once more carefully for any fissures or fractures.

12. With the final component specifications verified through trialing, preparation for cementing can begin.

Preparations for Cementing

Once cement mixing begins, working time is limited. Therefore, preparatory steps and instrument verification must be done in advance.

1. A cement restrictor plug is inserted into the medullary canal to prevent cement from migrating too far distally. Plug size is determined using trial plugs, and the depth of insertion is determined by measuring the plug inserter against the final stem to position it 1 to 2 centimeters deeper.

2. Gauze packs are placed in the acetabulum to protect it in case of cement overflow. Cement that inadvertently enters the acetabulum is difficult to remove and interferes with articulation.

3. Before mixing cement, all necessary components and instruments are verified and positioned within reach.

4. With the instruments and components ready, cement mixing can begin while the femoral canal is irrigated and dried.

Cementing and Implanting the Components

1. The bone cement is mixed until homogeneous and loaded into the cement gun.

2. The leg is held by the assistant with the tibia pointing toward the floor, maintaining external femoral rotation, and the retractor is positioned to elevate the femur for proper canal access.

3. The tip of the cement gun is inserted to the bottom of the femoral canal, filling the canal from bottom to top.

4. After cement insertion, a brief waiting period allows the cement to reach optimal consistency for stem insertion, typically around 2 minutes, varying with cement type and room temperature. Readiness can be assessed by touch: the cement should no longer adhere to a gloved finger.

5. The stem is advanced carefully, maintaining lateral positioning to avoid varus malpositioning, and controlling rotation to preserve the built-in anteversion of this model.

6. The stem is advanced fully until it reaches the predetermined depth.

7. Large bone-holding forceps can be applied to hold the stem in position while the cement sets.

8. Excess cement is removed from around the stem while still soft to prevent hardened fragments from causing impingement.

9. Setting time varies by cement type and room temperature but is typically 11 to 12 minutes. The leftover cement from mixing can serve as an indicator. Hardening is confirmed when tapping it against a metal surface produces a sharp click, indicating complete setting.

10. When the cement is hardened, the gauze packs are removed and the acetabulum is palpated to confirm it is clear.

11. The joint capsule edges are grasped with forceps on both sides of the incision to prevent capsular tissue from becoming interposed during reduction.

12. The final femoral head component is positioned and seated firmly with an impactor and mallet.

13. With the components fully assembled, the hip is ready for reduction and final stability testing.

14. The prosthesis is now fully implanted and the joint is stable. The surgical field can be irrigated before proceeding with wound closure.

Closure

Closure aims to secure the gluteus medius for abductor function and achieve hemostasis at all levels. The other layers to close are the capsule, fascia, subcutaneous tissue, and skin.

1. The capsule is closed securely by reapproximating both components of the inverted T-shaped incision using strong absorbable braided sutures, for example size 2.

2. Secure reattachment of the gluteus medius to the anterior greater trochanter is critical to restore hip abduction strength. This is achieved by suturing the tendon through bone tunnels. Two transosseous tunnels are created through the anterior greater trochanter.

3. Strong non-absorbable braided suture is used for tendon-to-bone fixation. The suture is passed through the tendon and transosseous tunnel twice to reinforce fixation. Both sutures are placed before tying to allow optimal tension adjustment.

4. Then, additional sutures are placed distally and proximally to close remaining gaps.

5. The fascia is closed inferiorly with interrupted absorbable sutures.
   
   The superior muscular portion can be closed with continuous absorbable suture.
   
   

6. The subcutaneous layer is closed with continuous absorbable suture to eliminate dead space.
   
   Approximation is achieved without excessive tension.
   
   

7. The skin is closed with either interrupted sutures or skin staples according to preference.