With the rise in healthcare costs and the increasing burden of hospitalization, there is a compelling argument for embracing outpatient total joint arthroplasty. Traditionally, joint replacement procedures have involved lengthy hospital stays and inpatient rehabilitation. However, in recent years, there has been a shift towards shorter hospitalizations due to advancements in surgical techniques, better pain management, and improved postoperative therapy pathways.

Our center's journey in minimally-invasive surgery began in 1996, when we explored techniques to minimize incisions in total hip arthroplasty. Over time, we perfected the approach, reducing the incision size to 6.5-9 cm. We also developed the concept of the "mobile window," allowing surgeons to visualize the surgical anatomy throughout the case. In addition, specialized instruments were created to enhance surgical exposure while minimizing tissue damage.

In a review of our initial experience with the mini-incision posterior approach, we found minimal complications and a significant reduction in patient length of stay, with an average of only 2.89 days. Encouraged by these results, we embarked on the two-incision total hip arthroplasty in 2001. This approach proved to be technically demanding but paved the way for innovative perioperative techniques that facilitated faster recovery and, in some cases, same-day discharge from the hospital.

When comparing the two-incision approach to the mini-posterior approach, we found that the latter offered several advantages, including ease of learning, greater flexibility, reduced blood loss, and the elimination of intraoperative imaging. With these benefits in mind, we started our ambulatory surgical center experience in 2008, aiming to offer same-day outpatient total joint replacement for suitable candidates.

 

Requirements for Outpatient Total Joint Arthroplasty

Creating a Perfect Environment for Ambulatory TJA

In the pursuit of excellence, it is imperative that ambulatory total joint arthroplasty (TJA) be performed in a setting that exudes professionalism and efficiency. That's why we have carefully chosen to conduct our outpatient surgeries in a fully equipped hospital or ambulatory surgical center (ASC). With a dedication to maximizing efficiency, our ASC consists of three state-of-the-art operating rooms where we accommodate two separate surgical teams and anesthesiologists. By running two rooms concurrently, we can perform a maximum of four to five procedures per day, ensuring ample time for patient recovery and physical therapy. Our goal is to discharge patients safely by early evening, allowing them to fully regain their strength and mobility. It is worth noting that, while we have the capabilities to keep patients overnight if necessary, no patient has ever required such extended care. 

A Hub of Comprehensive Services

Our ASC is impeccably equipped to handle any potential complications that may arise during surgery. We prioritize patient safety by providing full-service radiology facilities, equipped with conventional and fluoroscopic capabilities. This ensures that any unforeseen issues can be addressed promptly and effectively. Additionally, we have a dedicated physical therapy unit within the facility, where our patients receive intensive postoperative therapy as soon as sensation and motor strength return to their lower extremities. To maintain the highest level of quality, we have established solid partnerships with multiple vendors who assist us in the timely delivery, maintenance, processing, and servicing of the required equipment and implants for TJA. To further streamline our operations, we have ample storage facilities, a full-service central processing center, and large autoclaves for the necessary sterilization processes. Lastly, we have fostered a collaboration with a blood bank to accommodate patients who wish to predonate autologous blood.

Seamless Postoperative Care

A Major Component of Success

The success of outpatient total hip replacements relies heavily on the coordination of physical therapy and nursing services post-discharge from the ASC. We recognize the crucial role these services play in our patients' recovery, and thus, arrangements are made well in advance through our discharge planner at the ASC. Once patients return home, they commence home physical therapy the day after surgery. This initial therapy continues for approximately one to two weeks before transitioning to outpatient therapy. Throughout the recovery process, patients have immediate access to visiting nurse services. Regular visits from these skilled professionals ensure that patients receive the necessary care and support until it is no longer required.

Ongoing Communication and Support

At the Heart of It All

In the perioperative period, frequent contact between surgeon and patient is imperative. Our commitment to personalized care extends beyond the operating room. It is our routine to personally contact patients the evening of surgery and the following morning to address any concerns and answer questions from patients and their families. Furthermore, patients may visit our office for a wound check on the second postoperative day. Beyond this initial contact, subsequent patient communication is tailored to individual needs, ensuring comprehensive support until the two-week follow-up visit.

Crafting an Ideal Ambulatory Experience

Creating the Perfect Environment

The key to a successful ambulatory surgical experience lies in developing protocols that prioritize patient comfort, early mobilization, swift recovery, and timely discharge. These crucial protocols can be divided into preoperative, perioperative, postoperative, and outpatient stages.

PREOPERATIVE Stage: Setting the Foundation

In the crucial moments before surgery, we employ a meticulously crafted plan to optimize patient outcomes. This includes the implementation of acute normovolemic hemodilution procedures, where a unit of whole blood is taken from the patient in the holding room. To ensure safety and maintain intravascular volume, the removed blood is replaced with normal saline or lactated ringers. Extensive research supports this technique in reducing postoperative transfusions and hypotension. Additionally, patients are provided with carefully curated medications to preemptively manage pain and nausea.

PERIOPERATIVE Stage: Orchestrating Excellence

During the operation itself, we take utmost care to create an environment conducive to a smooth recovery. Our multidisciplinary approach focuses on meticulous attention to detail. To combat postoperative nausea, patients receive metoclopramide, ondansetron, and dexamethasone in the operating room. The administration of appropriate antibiotics before incision and continued throughout recovery plays a crucial role in minimizing infection risks. Foley catheters are not routinely used, thanks to rapid recovery from anesthesia and early mobilization, which has significantly reduced instances of urinary retention. To control volume and prevent hypothermia, patients receive warmed IV fluids and are equipped with a forced air warming device. Furthermore, we utilize anti-embolic stockings and pneumatic compression devices to reduce the risk of venous thromboembolism (VTE). To facilitate rapid motor and sensory recovery, we employ spinal anesthesia, tailored to each patient's needs. Throughout surgery, hypotensive anesthesia is employed to minimize bleeding, and meticulous hemostasis is maintained. At the conclusion of surgery, we infiltrate the periarticular and subcutaneous tissues with a carefully measured solution, aiding in pain management. Additionally, reinfusion drains are routinely utilized as part of our comprehensive blood management protocol.

POSTOPERATIVE Stage: Nurturing Recovery

Following surgery, our patients enter the postoperative phase, where their well-being is our top priority. In the recovery room, patients are kept warm, provided with the previously withdrawn blood for acute normovolemic hemodilution, and, if applicable, their pre-donated autologous blood. Prior to discharge, the reinfusion drain is skillfully removed by our attentive recovery room nurses. Continual intravenous fluid administration is maintained until the patient is able to tolerate sufficient oral intake. Anti-embolic stockings and pneumatic compression devices are essential in preventing venous stasis. Moreover, we employ cryotherapy units or ice to control local swelling and manage postoperative pain and nausea with carefully tailored medications.

AT HOME: A Continuation of Excellence

The transition from the ASC to home is seamlessly executed, ensuring that patients continue to receive exceptional care. Our commitment to ongoing communication is unwavering. Office contact is frequent, ensuring that patients feel supported and have any concerns promptly addressed. To further reinforce this support system, we personally contact patients at home on the evening of surgery and the following morning. Additionally, patients return to the office for a wound check on the second postoperative day. Daily visits from a dedicated visiting nurse ensure progressive recovery and provide direct contact with our office for any concerns. 

Tailored Home Medications

We take great care in prescribing appropriate home medications, ensuring patients have a comprehensive understanding of their treatment plan. This includes postoperative antibiotics, pain medications, thromboprophylaxis, and medications to manage swelling and enhance recovery. Furthermore, comprehensive instructions are provided to guide patients through their recovery journey.

Conclusion: A Journey of Excellence

The journey towards successful outpatient total hip replacement requires careful orchestration of various elements. From the perfectly equipped surgical center to comprehensive postoperative care, each step is thoughtfully designed with our patients' well-being and successful recovery in mind. With a commitment to excellence, personalized care, and ongoing support, we strive to create an attractive and inspiring environment for our patients to embark on their transformative journey towards improved mobility and a pain-free life.               

Surgical Technique: Patient Positioning and Landmarks

The Art of Positioning and Precision

The patient is delicately positioned on a standard operating table, embraced by the whispers of a lateral decubitus position. The surgical side rises towards the heavens, firmly securing the patient's existence with the aid of finely crafted hip holding devices. The pelvis, the sanctuary of balance and motion, rests on this intricate apparatus, allowing for a dance of movement and assessment. A carpenter's level, the maestro of alignment, ensures the harmony between the operative table, the hip positioner, and the sacred floor. With gentle palpation, the frontal plane of the pelvis reveals its secrets, guiding the surgeon towards profound surgical adjustments. A cautionary tale guides their hands, encouraging them to avoid forward rolls that could compromise the exposure and integrity of the acetabular cup. Remember, dear surgeon, the wisdom of the pelvic holding devices, for they enthrall the pelvis in a seductive forward flexion of up to 20 degrees, altering the path towards proper acetabular version.

The Dance of Planning and Precision

In the realm of total hip arthroplasty, precision is a divine dance. It begins with the meticulous preoperative templating, a ritual that invokes the essence of the patient's pelvis and affected hip. The surgeon gazes upon the anterior-posterior and lateral X-rays, unraveling the secrets hidden within. In the realm of minimally invasive THA, the importance of this ritual cannot be understated. The surgeon's biases intertwine with the patient's unique anatomy, resulting in a preoperative plan that aligns the stars of the head center, length, and offset. Like skilled cartographers, reference points are established, guiding the surgeon towards restoring the beauty of length and offset. The lesser trochanter and the superior femoral neck border become beacons of guidance, leading the surgeon towards a precise neck osteotomy. In this journey, the wisdom of standard intraoperative neck cutting guides becomes a trusted companion, ensuring the path towards artistry.

The Artistry of Incision and Exposure

In the realm of minimal incision total hip arthroplasty, the incision becomes a brushstroke of artistry. Its placement is of utmost importance, for it holds the key to visualizing the hidden world within the hip joint. Wide fields are draped, illuminating the bony and soft tissue landmarks that whisper the secrets of the perfect incision location. The high point of the pelvis, where the lumbar paraspinal muscles meet the lateral border of the posterolateral ileum, reveals its sacred presence to those skilled in the art of palpation. A line is drawn, connecting this sacred point to the heart of the greater trochanter, the vessel of movement. This second point becomes a beacon, shining with approximation and promise.

The incision, like a lyrical poem, embraces the greater trochanter in an oblique and parallel caress, revealing an angle of posterior devotion. Its length, a gentle expanse of 7 to 8 centimeters, echoes with the harmonious balance of the incision's distal proximity to the superior edge of the greater trochanter. Its center, slightly posterior to the proximal femur's midline, becomes the beacon of equilibrium, adjusting itself gracefully with the increasing thickness of the lateral adipose tissue. The surgeon, an artist with knowledge and experience, allows the incision's path to meander, harmonizing with the patient's unique skeletal anatomy and body habitus. In the embrace of more adipose tissue, the incision whispers a message of proximal translation, minimizing wound compromise and ensuring the path towards femoral canal exposure. In the realm of Crowe I-II hip dysplasia or the presence of formidable osteophytes, the incision declares its allegiance to distal translation, leading the way towards a breathtaking revelation. And for those in need of substantial lateral subluxation, the incision extends its touch, capturing the entirety of the patient's journey.

Patient Exposure: Unveiling the Hidden World

Once the sacred incision has been brought to life, the symphony of patient exposure commences. The subcutaneous tissue, delicately divided in line with the incision's melody, paves the way towards the deeper layers of truth. The fascia, like a secret treasure, reveals itself as the gluteus maximus fascia and fascia lata are delicately identified. A gentle touch guides the surgeon, reminding them not to undermine the precious adipose tissue, for it holds the vitality of vascularity and protects the sacred harmony of the wound. With grace, the deep fascial structures are unveiled, their fibers parting ways to reveal the grandeur of the gluteus maximus muscle. Should the opening be too tight, the fascial incision extends its embrace, offering an inch of solace to the inferior pole of the skin incision. But fear not, for the extension beyond the proximal pole of the skin incision is a rare necessity, reserving its presence only for the most unique of orchestrations. A modified Charnley retractor steps onto the stage, its design carefully crafted to harmonize with the skin edges and soft tissues. Its elongated arms and radialized blades embrace the shortened incision, offering a visual symphony of maximal visualization and minimal tension. In the realm of adipose abundance or well-developed gluteal musculature, a deeper posterior blade joins the symphony, conducting a concerto of flawless exposure.

Postoperative Journey: Artistry Awakens

As the patient awakens from the embrace of anesthesia, their journey towards authenticity continues. In the realm of a truly ambulatory total hip arthroplasty, the patient is accompanied by attentive nurses and physical therapists. Their hands hold the power to transform pain into healing, nausea into calm, and hypotension into equilibrium. The patient's recovery is carefully nurtured, ensuring that the echoes of discomfort do not progress into a symphony of despair. And so, the patient dances with the physical therapist, guided towards each step of progress. Transfers lead to protected ambulation, blossoming into independent mobility, and conquering the mountains of stairs that await them at home.

At Home: A Symphony of Caring

Once the patient returns to the sanctuary of their own home, the melody of care continues. The office becomes a constant companion, answering the questions that dance within the patient's mind and fostering discussions of care and treatment plans. The surgeon's voice reaches out, calling the patient in the evening and morning after surgery, a reassuring presence in the journey towards recovery. The office orchestrates daily visits from a visiting nurse, nurturing the patient's progress and tending to the delicate surgical dressing. The patient's understanding of postoperative medications is carefully sculpted, weaving a tapestry of knowledge. And so, the patient becomes the conductor of their own healing, guided by the symphony of care.

And so, the journey of total hip arthroplasty unfolds, a symphony of precision and artistry, guided by skilled hands and compassionate hearts. From the operating table to the patient's own home, the dance of healing continues, unveiling the hidden world within the hip joint and restoring the harmony of movement.

 

 

Total Hip Arthroplasty

 

Figure 41.1: Proper placement of incision is critical for mini-incision THA. The incision is generally located just posterior to the mid-portion of the greater trochanter and is angled parallel to a line directed towards the greater trochanter starting approximately two centimeters posterior to the high point of the iliac crest

 

of the acetabular anteversion angle. The superior, anterior and posterior edges of the greater trochanter are next identified. If difficulty is encountered in identifying the greater trochanter, a 20 gauge, 3.5 inch spinal needle may be used to palpate and confirm the precise location of the greater trochanter. A slightly oblique incision is marked, directed parallel to the anteversion angle previously identified. This incision is typically oblique and directed posteriorly 10 degrees to 20 degrees with respect to the long axis of the femur, usually measuring 7 to 8 cm in length with approximately 80% of the incision distal to the superior edge of the greater trochanter. The incision is centered slightly (approximately 5 mm) posterior to the midline of the proximal femur. It is moved posteriorly as the thickness of the lateral adipose tissue increases. One must avoid excessive posterior translation as this will greatly compromise visualization of the anterior acetabulum.

With experience, the location of the incision can be modified based on the patient’s skeletal anatomy and body habitus. In patients who have more adipose tissue, the incision is translated proximally 1 cm to minimize superior wound compromise during femoral canal exposure and preparation. In patients with Crowe I-II hip dysplasia or significant lateral subluxation caused by large medial wall osteophytes, the incision is translated distally. In cases of substantial lateral subluxation, the entire incision may extend distally from the most proximal border of the greater trochanter.

 

PATIENT EXPOSURE

Once the skin incision has been made, the subcutaneous tissue is divided in the line of the incision. The gluteus maximus fascia and fascia lata are identified. It is important to not undermine the adipose tissue off of the deep fascia. Doing so not only places at risk the vascularity of the skin and subcutaneous fat, it also creates a dead space that may allow for the formation of a seroma or hematoma which could compromise the integrity of the wound. These deep fascial structures are incised in the direction of their fibers. The gluteus maximus muscle is bluntly split. If the fascial opening is too tight, the fascial incision may be extended one centimeter distal to the inferior pole of the skin incision. Proximal extension of the fascial incision beyond the proximal pole of the skin incision is rarely required. A modified Charnley retractor designed to minimize tension on the skin edges and soft tissues while providing maximal visualization is then placed into the wound. These modifications include both a lengthened anterior arm as well as radialized blade edges that match the contour of the retracted skin edges of the shortened incision (Fig. 41.2). Occasionally, a deeper posterior blade is necessary for patients with more adipose tissue or well developed gluteal musculature.

 

 

 

Total Hip Replacement in an Ambulatory Surgical Setting

 

Figure 41.2: Modified Charnley retractor with an elongated anterior arm and curved blades to minimize tension on the skin edges

Figure 41.3: The short external rotators and posterior hip capsule are seen posterior to the greater trochanter

 

The surgical hip is brought to a position of neutral to slight extension, gravity assisted adduction, and lightly forced internal rotation. This position places on tension the short external rotators and posterior hip capsule and moves the surgical field well away from the sciatic nerve. The trochanteric bursa, pericapsular fat, short external rotators and posterior hip capsule are not separated from each other during this portion of the dissection. By not surgically separating these structures, the tendons of the piriformis and conjoined tendon of the superior and inferior gemelli and obturator internus tend to remain adherent to the edge of the capsular flap and allow for a more robust closure of this layer at the conclusion of the procedure. The border between the piriformis and gluteus minimus is identified and a Cobb elevator may be placed to gently elevate the posterior edge of the gluteus minimus off of the posterior-superior hip capsule. The tip of the electrocautery is gently bent to facilitate its reach behind the posterior greater trochanter onto the piriformis fossa. The short external rotators and underlying hip capsule are then released as one continuous sleeve from the piriformis fossa and posterior femoral neck with electrocautery (Fig. 41.3). This is done in the standard “hockey-stick” fashion, first along the superior edge of the piriformis tendon from the acetabular rim to the piriformis fossa, and then extending distally to release the conjoined tendon and posterior hip capsule

The hip is atraumatically dislocated posteriorly in slight flexion (approximately 15 degrees), adduction and internal rotation. The location for the femoral neck osteotomy is identified as preoperatively templated and is easily referenced off of either the lesser trochanter or superior neck-greater trochanteric junction. To facilitate visualization of the lesser trochanter the hip is brought into extension and a blunt Cobra retractor may be placed just distal to the lesser trochanter. Occasionally, the upper edge of the quadratus femoris must be released to visualize the upper portion of the lesser trochanter. Care should be taken to avoid releasing more distally into the quadratus femoris as bleeding may be encountered. There should be ample room to place a neck cutting guide if desired.

The femoral neck osteotomy is then made with a reciprocating saw with cutting teeth only on one side (Fig. 41.4A). This is a critical instrument for use in this procedure because its design protects against inadvertent injury to the posterior structures including the sciatic nerve. As the femoral neck is osteotomized from the medial calcar towards the greater trochanter, it is important that the first assistant gradually flexes the hip. This brings the greater trochanter into direct visualization within the mobile window and avoids accidental

 

 

 

 

 

 

Total Hip Arthroplasty

 

Figures 41.4A to C: (A) The femoral neck osteotomy is performed with a single sided reciprocating saw blade to minimize risk to surrounding soft tissues. The first assistant may gently flex the hip during the osteotomy to facilitate visualization of the femoral neck. The osteotomy is opened with hip extension (B) and the femoral head removed (C)

 

trochanteric notching. The vertical limb of the neck cut then is made by starting proximally at the junction of the piriformis fossa and medial boarder of the greater trochanter and extending distally to the previous osteotomy. The hip is then brought back into extension. This generally rotates the femoral head into flexion and exposes the cut cancellous surface of the neck (Fig. 41.4B) facilitating removal of the femoral head which is easily grasped with a bone holding clamp (Fig. 41.4C). Difficulty may be encountered in removing large femoral heads or heads with massive peripheral osteophytes through the incision. In such cases the Charnley retractor may be relaxed or removed in entirety. This usually allows the femoral heads to be removed without need to extend the incision. Occasionally, in cases of severe protrusio or large osteophytes, an in situ femoral neck osteotomy may be necessary. The hip is returned to a neutral position after the femoral head has been removed and the height of the neck osteotomy has been confirmed.

 

ACETABULAR PREPARATION

It is important to understand that all parts of the acetabulum should be easily visualized throughout this procedure through the surgical incision. Using the concept of the mobile

 

 

 

Total Hip Replacement in an Ambulatory Surgical Setting

 

window, different parts of the acetabulum can be highlighted through the differential relaxing and tightening of reciprocal acetabular retractors and by changing the position of the femur. For example, visualization of the anterior acetabulum is facilitated with gentle femoral flexion and slight internal rotation, pressure on the anterior acetabular retractor and relaxation of the posterior retractor while posterior acetabular visualization is facilitated with neutral limb position, relaxation of the anterior acetabular retractor and gentle pressure on the Kocher retracting the posterior capsular flap.

The anterior acetabular retractor is placed first. Many designs of these retractors exist. We prefer a long, curved Homan retractor with a pointed single tip and a radialized blade that fits against the arc of the retracted soft tissues and skin edges (Fig. 41.5A). Self-illuminating retractors may be used to focus light directly into the wound to aid with visualization. The hip is held in slight internal rotation and the anterior acetabular retractor is placed into the acetabulum. The surgical assistant then brings the hip into neutral rotation as the surgeon lifts the tip of the retractor up, through the anterior hip capsule and over the anterior wall and column of the acetabulum so as to retract the proximal femur anterior to the acetabulum.

It is critical to achieve adequate anterior exposure for later stages of acetabular preparation. In large, muscular men, difficulty may be encountered in retracting the proximal femur anteriorly. Inadequate femoral mobilization may result in proximal femoral fracture or anterior acetabular fracture from excessive pressure on the anterior acetabular retractor, eccentric reaming of the posterior acetabulum resulting in compromise of the posterior wall and/or column, or acetabular cup malposition into relative retroversion and/or excessive abduction. In such cases, the superior capsule may be released at the rim of the acetabulum. This usually allows for adequate proximal femoral mobilization. In rare cases where this does not provide adequate visualization, an anterior capsulotomy is performed by directing a scalpel blade, under direct visualization, beginning at the superior pole of the capsulotomy and continuing anteriorly and progressively inferiorly until adequate capsular relaxation is achieved. Generally, by the time an additional 90 degrees of hip capsule has been incised, the femur can be easily retracted anteriorly. Overzealous retraction of the proximal femur should not be necessary if the incision is properly located, the limb and retractors are appropriately positioned, and the capsular tissues sufficiently released.

A second retractor is than placed to retract the inferior hip capsule. We prefer to use a blunt Cobra retractor with a tip bent to 45 degrees (Fig. 41.5A). It is placed from within the acetabulum, deep to the transverse acetabular ligament, through the obturator foramen and

 

 

 

Figures 41.5A and B: (A) A blunt Cobra retractor with a 45 degree tip is placed below the transverse acetabular ligament and an anterior acetabular retractor with a curved blade is used to retract the femur anteriorly. A Kocher is used to control and retract the posterior hip capsule (B) allowing full acetabular visualization

 

 

 

Total Hip Arthroplasty

 

Figure 41.6: Reamer sleeve in place to protect the inferior skin edge during acetabular preparation

 

hooked around the medial acetabular wall. If there are significant inferior acetabular osteophytes extending over or obliterating the transverse acetabular ligament and the inferior introitus to the acetabulum, they are removed with a rongeur or osteotome before the inferior retractor is be placed. A Kocher clamp is then placed on the posterior-superior corner of the capsular flap and is used to retract the posterior capsule during acetabular preparation. This clamp provides excellent visualization of the posterior acetabulum and obviates the need for placement of a large posterior retractor that could place posterior structures including the sciatic nerve at risk. With the anterior Homan retractor, the blunt Cobra retractor, and the Kocher clamp in place full visualization of the acetabulum should be achieved (Fig. 41.5B).

The pulvinar and medial wall osteophytes may be excised using a large curette or rongeur to reveal the true medial wall of the acetabulum. The acetabular labrum is resected by selectively tightening and loosening the anterior and posterior retractors to directly visualize the anterior and posterior components of the labrum. The remaining islands of acetabular cartilage may be removed with a large acetabular curette. The surgical assistant holds the anterior and inferior retractors. The posterior Kocher is controlled by the surgeon. The limb is allowed to lie dependent over the opposite leg. Acetabular reaming is then commenced, generally with the largest reamer that will bottom out in the patient’s socket. During the reaming process it is important to make sure that the reamer handle does not lever on the femur and bias the reamer posteriorly causing eccentric reaming, and ultimately, compromise of the posterior wall and column of the acetabulum. It is also important to ensure that the reamer sleeve is in proper position to protect the skin edge at the inferior pole of the incision (Fig. 41.6). Offset reamers may be used to minimize both soft tissue and bony impingement during acetabular preparation.

When inserting the acetabular component through the incision, the component should be introduced in retroversion so that it is oriented with its internal surface directed posteriorly and its external convex surface directed anteriorly (Fig. 41.7). It then is slid down along the internal radius of the anterior retractor to the level of the acetabulum and then is redirected into its appropriate position. This maneuver of utilizing the external convex geometry of the acetabular shell and orientating it to the internal concave geometry of the Charnley retractor blades is particularly important when inserting large diameter sockets in small incisions and avoids dragging soft tissue into the prosthetic/host bone interface. Before impacting the acetabular component into position great care should be taken to avoid the entrapment of soft tissue between the outer surface of the acetabular component and the prepared acetabular bone to ensure maximal prosthetic-host bone contact for osseousintegration.

 

Total Hip Replacement in an Ambulatory Surgical Setting

 

Figure 41.7: Acetabular component inserted in retroversion to facilitate passage through the incision and surrounding soft tissues

 

 

 

Figures 41.8A and B: A straight acetabular inserter may impinge on the inferior edge of the wound which could cause the cup to be placed in excessive abduction (A). Such impingement may be avoided with the use of an offset acetabular inserter (B)

The acetabular component is inserted with an ideal true abduction angle of 40 to 45 degrees and an ideal true anteversion angle of approximately 20 degrees.

While a standard acetabular inserter may be used with this approach (Fig. 41.8A) it may impinge on the inferior pole of the wound which may bias the final component position into an excessively vertical position. To avoid such impingement, a dogleg acetabular inserter may be utilized (Fig. 41.8B). The midportion of this inserter is designed to avoid soft tissue impingement at the wound edges and may greatly facilitate component positioning. The acetabular inserter is aligned to assure appropriate acetabular abduction and anteversion and is then struck firmly with a mallet to fully seat the cup (Fig. 41.9).

Anterior and inferior peripheral osteophytes are generally removed once the acetabular component has been inserted (Fig. 41.10). A 1.5 cm slightly curved osteotome is used to excise potentially impinging anterior and anteroinferior osteophytes after the acetabular shell has been impacted into position and prior to insertion of modular articular liners. Straight osteotomes generally are used to excise posterior and posteroinferior osteophytes.

 

 

 

Total Hip Arthroplasty

 

Figure 41.9: The cup fully visualized and well seated in the acetabulum

 

 

 

Figure 41.10: Peripheral osteophytes are easily identified and removed with a curved osteotome under direct visualization

 

Visualization and excision of the posterior osteophytes is much easier if left until the trial femoral component is in place and the hip has been reduced as the posterior hip capsule is under tension unveiling these posterior structures.

Acetabular screws may be easily placed through the minimally invasive posterior incision If deemed necessary for additional acetabular fixation. Acetabular screw holes are readily seen, and using standard, flexible drill bits, drill guides, depth gages, and articulating screw drivers, the surgeon should be able to place screws without difficulty (Fig. 41.11).

For hip systems that call for the placement of a modular acetabular liner into the acetabular shell, this liner is now inserted and dialed into appropriate position before engagement into the locking mechanism of the acetabular component. It is important to ensure that no soft tissue is trapped between the acetabular shell and the liner. The liner is then impacted into position and locking is confirmed. The anterior and inferior retractors are removed and the Kocher clamp is removed from the posterior hip capsule.

41

 

 

 

 

 

 

Total Hip Replacement in an Ambulatory Surgical Setting

 

Figure 41.11: For additional fixation, screws may be placed under direct visualization

 

FEMORAL PREPARATION

The Charnley retractor is relaxed prior to preparation of the femur. This functionally lengthens the skin incision and reduces the risk of damage to the superior skin edges during reaming and/or broaching of the femoral canal. The nonoperative extremity is moved under the surgical drapes into a position of flexion with the knee at the edge of the operating table. The surgical assistant then presents the proximal femur into the wound by bringing the leg into a position of hip internal rotation, adduction, and neutral to slight flexion of approximately 10 degrees. The knee of the surgical extremity should sit just posterior to the nonoperative knee which remains flexed on the table. A specially designed femoral elevator is then placed under the anterior surface of the femur and is used to further present the proximal femur into the surgical wound. This retractor has a curved blade that fits within the contour of the superior skin edge. The design of this retractor not only reduces tension on the wound but also facilitates placement of femoral instrumentation while minimizing damage or abrasion to the superior and superoposterior skin edges. If damaged, the compromised skin should be trimmed prior to closure to avoid later wound compromise. With appropriate incision location, leg positioning, and the use of specially designed skin protector/femoral elevators, damage to the wound edges should be extremely rare.

With the proximal femoral elevator held in place by the surgeon or assistant, any remaining fibrous tissue, capsule, or piriformis tendon stump is removed from the area of the piriformis fossa to allow an unobstructed view of the proximal femur. The initial hand reamer or canal finder is positioned centrally and laterally into the cancellous bone of the femoral neck and directed down the femoral canal (Fig. 41.12A). If the body habitus is such that the initial canal finder cannot be passed straight down the femoral canal without impingement on the superior margin of the wound, then the proximal skin incision should be lengthened without hesitation. This is particularly important if a fully coated type of implant is being used so as to avoid skin abrasion and compromise of the wound edges.

A box osteotome or lateralizing reamer is used to remove any remaining lateral femoral neck that may direct the femoral broaches into varus (Fig. 41.12B). The femoral canal is now ready to be reamed and/or broached. Specially designed broach handles that have lower profiles and rounded edges are used to minimize impingement on the posterosuperior edge of the skin incision. However, there still remains a tendency for the proximal pole of the incision to apply a retroverting force onto the broach handle. As such, it is important to maintain rotational control of the broach handle. A Tommy bar may be placed through the

 

 

 

 

 

Total Hip Arthroplasty

 

Figures 41.12A and B: The femoral canal is first entered with a hand awl

(A) and then a box osteotome (B) or lateralizing reamer may be used to remove remaining lateral femoral neck to prevent varus canal preparation

 

 

 

Figures 41.13A and B: To prevent skin abrasion during canal preparation, the broaches are introduced in retroversion (A) until the cutting edges have cleared the superior skin edge and then the broach position is corrected to the appropriate femoral anteversion (B) before host bone is engaged

 

broach handle to maintain appropriate anteversion of the broach during femoral preparation. The avoidance of significant hip flexion during broaching is also important in minimizing impingement of the broach handles on the posterior-superior corner of the incision.

There are several ways in which the proximal pole of the skin incision is protected from broach abrasion during this portion of the procedure. One useful technique is to initially introduce the broach in retroversion (Fig. 41.13A). A major advantage of using a proximally coated, robustly tapered femoral component is that rotation of the rasp during the first several centimeters of its insertion has no effect on the final component interfaces. The broach is inserted in 60 degrees to 90 degrees of retroversion and as soon as its proximal teeth have moved beyond the proximal pole of the skin incision, the broach is rotated into its definitive anteversion (Fig. 41.13B). The proximal femoral elevator is also very useful to protect the superior pole of the wound during femoral canal preparation. The elevator is initially placed in its normal position, parallel to the long axis of the shaft of the femur until the broach has seated below the proximal margin of the skin wound. The elevator is then allowed to slide around the medial femoral neck so that its internal radius is placed between

 

 

Total Hip Replacement in an Ambulatory Surgical Setting

 

Figure 41.14: Modular stem in place prior to placement of modular neck and head

 

the medial edges of the broach/broach handle and the posterosuperior skin edges and thereby protect the proximal posterior corner of the wound from any incidental broach induced abrasion.

The femoral canal is prepared with successively larger broaches until an appropriate sense of fit and fill has been achieved and the broach has been demonstrated to be axially and rotationally stable at the level of the femoral neck osteotomy. In general, this broach should be roughly the same size as that predicted on the preoperative template. Once the definitive broach has been selected, a provisional reduction is performed with the trial femoral neck and head so as to fine tune leg length and offset. We frequently use a stem system that has a modular neck (Fig. 41.14) (Kinectiv Technologies, Zimmer Inc., Warsaw, IN). This design lends itself well to short incision surgery by allowing for seating of the broach and stem without impingement of the neck on the posterior soft tissues. This system also allows for the preparation of the femur independent of the neck. The neck anatomy and head center are then re-established with respect to length, offset and version with modular neck trials. When satisfied with the trial reduction, the trial components are removed, and a D and C curette is lightly applied to the prepared proximal femur to remove any soft tissue that may been inadvertently introduced during the broach process.

The final stem is then opened and pressed down the canal by hand and introduced initially, similar to the broach, in substantial retroversion to allow the neck to clear the posterosuperior skin edge (Fig. 41.15A). On occasion, particularly when placing a femoral component with a long or extended offset neck, difficulty may be encountered in getting the femoral neck to clear the posterosuperior skin edge and fascia. Bringing the limb into neutral abduction as well as extension relaxes the skin and fascia facilitating the reduction of the neck of the femoral component under these layers. For femoral components with modular necks, such maneuvers are rarely necessary as the final neck is placed after the stem is fully seated into the femur. Once the stem has been placed deep to the skin and fascia, final component rotation is achieved and the stem is impacted into final position and axial and rotational stability are confirmed (Fig. 41.15B).

Femoral head trials are then applied sequentially until appropriate leg length and hip joint tension and stability have been achieved. Leg lengths may be assessed using standard techniques including lining up the knees and ankles with the hips in neutral abduction, by push-pull testing to judge head shuck within the acetabulum, or by judging the relationship between fixed points on the proximal femur and pins firmly placed into the pelvis prior to

 

 

 

 

 

Total Hip Arthroplasty

 

Figures 41.15A and B: The femoral component is introduced in retroversion (A) to allow the neck to clear the superior skin edges and is then turned to the appropriate position prior to impaction and final seating of the implant (B)

 

 

 

Figure 41.16: A modified head impactor that avoids soft tissue impingement is used to seat the femoral head

Figure 41.17: Under direct visualization implant position and hip stability and range of motion are confirmed

 

the dislocation of the native hip. It the superior soft tissues prevent easy placement of the head trial on the femoral stem, side mounting head trials may be used as they allow for easier placement of the head trial over the Morse taper. Once the final head length has been selected the Morse taper is presented into the surgical wound with hip adduction, internal rotation, and neutral extension. The taper is cleaned and dried and the femoral head is struck once with a modified, offset head impactor that allows for firm impaction of the femoral head without compromise of the superior skin edges (Fig. 41.16). A final reduction is performed and hip range of motion, stability and leg lengths are confirmed (Fig. 41.17). The periarticular tissues and skin edges are injected with 0.25% marcaine with epinephrine to aide with postoperative analgesia.

 

Total Hip Replacement in an Ambulatory Surgical Setting

 

Figure 41.18: The posterior capsule and short external rotators are repaired to the greater trochanter through drill holes with suture

Figure 41.19: Typical mini-posterior surgical site after wound healing

An enhanced posterior capsular closure is then performed using number 1 Vicryl suture placed in a figure of eight fashion through the posterior-superior hip capsule and piriformis tendon at the point at which the radial and longitudinal portions of the capsulotomy meet. A second suture is placed approximately 1.0 to 1.5 cm distal to this through the posterior limb of the capsule and the conjoined tendon of the superior and inferior gemelli and the obturator internus. Drill holes are then placed through the greater trochanter into the piriformis fossa, taking care that the starting point is at least 1 cm below the tip of the trochanter and 1 cm anterior to the posterior boarder of the trochanter to avoid a stress riser and possible trochanteric fracture. Number 4 (22 gauge) surgical wire is then doubled over and placed through the drill holes to be used as suture passers. The free ends of the suture are then brought through the drill holes and are tied to each other with the limb in neutral rotation and 15 to 20 degrees of abduction (Fig. 41.18). A reinfusion drain is placed and the wound is closed in layers and the final dressing applied (Fig. 41.19).

 

HOW TO START

Patient selection is of paramount importance in beginning outpatient TJA. Patients must have a desire to be part of something new, a paradigm shift in how TJA are performed. They must have a clear understanding of the traditional environment of conventional TJA and how ambulatory surgery differs. We have found that patients who select ambulatory TJA are commonly motivated by a desire to stay out of the hospital and to undergo a rapid recovery program. Many of these patients are looking forward to not playing the part of a “patient” and returning to a normal lifestyle quickly. Patient education is very important and we spend considerable amount of time with each patient describing the procedure, explaining what they can expect and, just as importantly, what is expected of them throughout the perioperative period.8-10 It is imperative to select patients that are healthy and without significant medical comorbidiities that may make recovery difficult or result in perioperative medical complications. Initially, ideal patients to undergo ambulatory TJA are thin, young, and healthy with good bone stock, minimal arthritic deformity, avascular necrosis or Crowe I or II dysplasia. With experience patient selection may expand to include more challenging cases with respect to disease, deformity, and body habitus.

Pathways in the surgeon’s office must be created so that the surgical staff knows how to handle ambulatory patients and meet their unique needs. The anesthesiologists, nurses,

Total Hip Arthroplasty

 

physical therapists and staff at the ambulatory center need to know what is needed and expected of them in order to perform outpatient TJA. This comes through education and taking the time to develop clinical pathways that facilitate rapid patient mobilization and timely discharge from the center. Relationships with vendors must also be developed to ensure that the ASC has an adequate supply of equipment, streamlined instrument trays, and implants so that cases may be performed in an efficient manner.

 

Results                         

We performed our first ambulatory ASC THA on 6/30/2008 and have subsequently performed over 200 outpatient THAs. The age range of our patients is 22-69 with a mean of

54. These patients have a mean of one medical comorbidity with a range of 0-3. Our average surgical time is 43 minutes with a range of 31-68 minutes. We have experienced five major complications. There was one emergency room visit for an over-narcotized patient that required 6 hours of observation and an injection of naloxone, after which they were discharged home. There was one anterior hip dislocation in the recovery room which was immediately discovered. The patient was revised at the ASC that day and discharged home that same evening. There was another anterior dislocation in the first two weeks after surgery that was treated with an isolated cup revision. Two patients were taken to our main hospital for irrigation and debridements at two and three weeks postoperatively for draining hematomas. One patient had positive intraoperative cultures and was treated successfully with six weeks of intravenous antibiotics.

 

Conclusion                        

While the majority of our patients still undergo traditional THA in a hospital setting, ambulatory surgery is becoming an increasing part of our practice as patients are looking for a more rapid, streamlined and efficient total hip replacement. The actual technique that we use is familiar and converting this technique to outpatient surgery should be relatively simple for most surgeons. What is unique is the notion that total hip replacement may be safely and effectively performed on an outpatient basis. However, as cost constraints and patient demand for these procedures increases we predict that ambulatory THA in appropriately selected patients will become more common place.

 

References                       

1. Hartzband MA. Posterolateral minimal incision for total hip replacement: technique and early results. Orthop Clin North Am 2004;35:119-29.

2. Berger RA. Total hip arthroplasty using the minimally invasive two-incision approach. Clin Orthop Relat Res 2003;417:232-41.

3. Berry DJ, Berger RA, Callaghan JJ, Dorr LD, Duwelius PJ, Hartzband MA, Lieberman JR, Mears DC. Minimally invasive total hip arthroplasty. Development, early results, and a critical analysis. Presented at the Annual Meeting of the American Orthopaedic Association, Charleston, South Carolina. J Bone Joint Surg Am 2003;85:2235-46.

4. Archibeck MJ, White RE Jr. Learning curve for the two-incision total hip replacement. Clin Orthop Relat Res 2004;429:232-8.

5. Bal BS, Haltom D, Aleto T, Barrett M. Early complications of primary total hip replacement performed with a two-incision minimally invasive technique. J Bone Joint Surg Am 2005;87: 2432-8.

6. Oishi CS, D’Lima DD, Morris BA, Hardwick ME, Berkowitz SD, Colwell CW Jr. Hemodilution with other blood reinfusion techniques in total hip arthroplasty. Clin Orthop Relat Res 1997;339:132-9.

7. Goodnough LT, Despotis GJ, Merkel K, Monk TG. A randomized tria