Hip Arthroscopy in Patients With Lower-Extremity Amputations: Patient Positioning and Traction Technique

Abstract

Improved battlefield survival rates have resulted in a significant number of young active patients with lower-extremity amputations. Because of the increased demands placed on their hips, patients with amputations may be more susceptible to the sequelae of hip pathology and femoroacetabular impingement. Arthroscopic management of hip pathology may be successfully performed in patients with ipsilateral, contralateral, or bilateral lower-extremity amputations. We describe our experience in this unique patient population. A technique for secure patient positioning that provides sufficient countertraction in the case of contralateral amputation is described, as is the use of skeletal traction with a temporary external fixator for joint distraction in patients with ipsilateral amputations. Considerations specific to patients with high transfemoral amputations are discussed as well.

Modern body armor technology and improved battlefield care have resulted in the highest combat injury survival rates in history during the conflicts in Iraq and Afghanistan.1, 2 Combat operations have led to a substantial number of young veterans with single- or multiple-limb amputations who remain active because of advances in rehabilitative care and prosthetic technology. Many of these patients—those with transfemoral amputations in particular—rely on their hips to efficiently power gait, thereby preserving independent mobility.

We have treated a small cohort of patients with intra-articular hip pathology in the setting of concomitant ipsilateral or contralateral lower-extremity amputation. As combat-wounded veterans continue to transition to the care of Veterans Administration hospitals and other civilian providers, hip arthroscopists may encounter such patients in their own practices.

Because the symptoms of femoroacetabular impingement frequently worsen in the seated position,³ patients with amputations may be particularly prone to this condition because of the extended daytime hours that may be spent in wheelchairs. The use of manual wheelchairs requires increased hip flexion angles as compared with standard gait, which may further exacerbate hip pain in these patients. For those patients with amputations who are able to use prostheses, efficient balanced ambulation may be compromised by hip pathology, potentially making them more likely to have debilitating gait disturbances. We describe our technique of positioning and joint distraction for hip arthroscopy in patients with amputations and offer an illustrative example of a combat-injured service member with bilateral high transfemoral amputations (Video 1).

Technique

Preoperative planning is critical and allows for an individualized approach to each patient (Table 1). History taking should inquire about the presence of symptomatic neuromas or changes in gait pattern so that concomitant procedures such as neurectomy or myodesis revision may be performed if indicated. Advanced imaging such as magnetic resonance imaging or computed tomography is obtained preoperatively to identify the location of neurovascular structures so that transosseous skeletal traction may be safely applied in the case of ipsilateral amputation. In some patients, prior soft-tissue trauma or surgical transposition has resulted in a nonanatomic location of these structures. Furthermore, any history of wound complications, flap coverage, or painful scarring should be considered because these may influence the planned location of surgical incisions.

Table 1.

Advantages and Disadvantages of Skeletal Traction for Hip Arthroscopy

Advantages

Familiar supine position

Reliable joint distraction

Ease of conversion for concomitant open surgery

Disadvantages

Limited capacity for dynamic impingement examination

Restricted rotation arc may limit peripheral compartment visualization

Additional surgical preparation required

Hip arthroscopy in the supine position as described by Byrd⁴ in 1994 is the preferred position for patients with lower-extremity amputations, particularly those at the transfemoral level. This allows traction to be applied in a longitudinal fashion regardless of limb involvement (i.e., ipsilateral, contralateral, or bilateral amputations) and level (i.e., transfemoral, through-knee, or transtibial).

In the case of a contralateral amputation (i.e., nonoperative extremity) whereby countertraction cannot be applied through a traction boot, a well-leg holder (Well Leg Support; Mizuho OSI, Union City, CA) is used (Fig 1). The patient is positioned, and the nonoperative extremity is secured before placement of the perineal post. To increase friction between the well-leg holder and the patient's residual limb, both are wrapped with Coban self-adherent wrap (3M Nexcare, St. Paul, MN). For a transfemoral amputation, a hip spica technique is used to prevent the residual limb from pulling out of the Coban wrap when traction is applied. A layer of egg crate padding may be placed under the spica portion of the Coban wrap to protect the abdominal skin. The residual limb is then securely taped to the well-leg holder with 3-inch silk or foam tape (Fig 2). The pelvis and torso are likewise secured to the table with tape while direct contact of the adhesive on the skin is avoided. We have found this to provide satisfactory countertraction stability, thus negating the need for skeletal traction in the nonoperative extremity.

Fig 1.

In this case of bilateral high transfemoral amputations, countertraction is provided by securing the torso and nonsurgical (right) residual limb to the traction table. A hip spica Coban wrap is applied over a layer of egg crate. A well-leg holder, also wrapped in Coban wrap, provides increased friction at this interface. The patient is positioned on the table such that the perineal post can later be placed securely without moving the patient.

Fig 2.

The nonsurgical (right) extremity is secured to the well-leg holder with 3-inch tape over the Coban wrap before the perineal post is placed.

For amputation ipsilateral to the site of planned arthroscopy, skeletal traction is used (Fig 3). According to preoperative planning and the location and patency of the neurovascular structures, the traction pin may be placed in any orientation between the coronal and sagittal planes. A centrally threaded 5-mm bicortical pin (Stryker, Kalamazoo, MI) is recommended because of the forces required for adequate hip distraction. For high transfemoral amputations, the unbalanced pull of the iliopsoas and abductor muscle group against the adductors may result in an externally rotated resting position. In this case the extremity will need to be internally rotated at the time of arthroscopy, particularly if a posterolateral portal is planned, so the trajectory of the skeletal traction pin should take this into account. The pin should be placed such that after the femur is appropriately rotated for arthroscopy, the surgeon's hands are minimally impeded by the skeletal traction construct. In addition, the perineal post may impinge on the traction apparatus if it is placed in a transverse plane in patients with high transfemoral amputations; this impingement results in an excessive abduction force vector on the femur. For this reason, we recommend an anterior-to-posterior trajectory using an open incision as needed to protect vital structures when one is placing a traction pin in the subtrochanteric or midshaft region of the residual femur.

Fig 3.

(A) Preoperative anteroposterior radiograph of surgical left hip and (B) intraoperative anteroposterior fluoroscopic image of a 5-mm centrally threaded skeletal traction pin placed in the subtrochanteric region. An oblique trajectory is selected to allow the pin to traverse the sagittal plane once the leg is internally rotated for hip arthroscopy. The pin is placed sufficiently proximal to the distal end of the femur to minimize fracture risk while providing sufficient bone stock to allow internal fixation should a fracture occur.

Because preservation of residual limb length is of critical importance to these patients, the skeletal traction pin should be placed proximal enough to ensure that it does not pull through the end of the bone once traction is applied. This is of particular importance in patients in whom disuse osteopenia may be present because of limited weight-bearing activity. Furthermore, the traction pin should be placed proximal enough to allow sufficient bone stock for open reduction–internal fixation should a fracture through the transosseous stress riser occur.

After sterile placement of the transosseous traction pin in the ipsilateral (operative) residual limb, an external fixator (Hoffmann 2 or 3; Stryker) is constructed (Fig 4). Bars of an appropriate length are selected to allow the fixator to be secured to the traction arm (90° Pin and Wire Holder; Mizuho OSI) on the fracture table (Fig 5). The perineal post is positioned, and distractibility of the hip is confirmed with fluoroscopy. Attention is paid to the rotational orientation of the femur as well as the traction vector to ensure optimal arthroscopic access while using the lowest necessary traction force. Traction is released, the hip is reduced, and the leg is prepared and draped in the standard fashion for hip arthroscopy. The traction pin and external fixator clamps are prepared into the surgical field. After arthroscopy, the skeletal traction pin is removed in a sterile fashion, and all incisions are closed and dressed.

Fig 4.

(A) Lateral and (B) frontal views of external fixation construct used for hip distraction. The torso is secured to the surgical table with 3-inch foam tape placed over the spica wrap.

Fig 5.

Traction apparatus. (A) After the 5-mm centrally threaded transosseous pin is placed, a trapezoidal external fixator is constructed with 8-mm bars. (B) The transverse 8-mm rod of the external fixator is fastened to the 90° pin and wire holder, and (C) this apparatus is secured to the traction unit on the fracture table.

Discussion

We have used the described positioning and traction techniques to successfully perform 5 hip arthroscopies in 5 patients with lower-extremity amputations. Among these 5 patients, of whom 3 had ipsilateral transfemoral amputations, 1 had an ipsilateral transtibial amputation, and 1 had bilateral transfemoral amputations, we have not encountered any complications related to the positioning technique or traction apparatus.

The advantages of the skeletal traction technique for hip arthroscopy ipsilateral to a lower-extremity amputation include the familiarity of supine positioning for many hip arthroscopists, as well as the reliable joint distraction that is achieved (Table 2). Furthermore, for those patients in whom concomitant open surgery is required, conversion is relatively straightforward and in many cases may be performed without changing the patient's position. Limitations specific to this approach are largely related to restricted intraoperative range of motion. Dynamic impingement examination may be limited if the hip cannot be fully flexed, and visibility may be compromised in the peripheral compartment because of the restricted rotational capacity of the external fixator–traction pin construct.

Table 2.

Pearls and Pitfalls Associated With Skeletal Traction for Hip Arthroscopy

Pitfalls	Pearls
Fracture of residual limb long bone	Utilize more proximal location for transosseous pin
Anticipate disuse osteopenia
Soft-tissue complications	Critically evaluate soft-tissue envelope preoperatively
Understand limb coverage surgical history
Neurovascular injury/neuroma	Study local anatomy on advanced imaging preoperatively

Regarding our technique for stabilizing the nonsurgical residual limb in the case of a contralateral (or bilateral) amputation, the main advantage is that it avoids the need for placement of skeletal traction in this extremity. Caution should be used in patients with compromised soft tissue of the contralateral limb or abdomen in whom sheer forces may be harmful. Many of these patients have undergone extensive skin grafting procedures and may be particularly prone to sheer stresses applied across the soft-tissue envelope. In these cases it would be reasonable to consider contralateral skeletal traction to adequately stabilize the patient on the operating table.

Distraction for hip arthroscopy using an external fixator has been described by Flecher et al.⁵; however, in their technique, pins are placed in both the femur and pelvis to avoid the use of a perineal post. The fixator itself is then used to generate joint distraction. This is a different application of the external fixator compared with our description, in which the fixator is used to extend the reach of the traction arm to the patient's shortened residual limb.

Merrell et al.⁶ proposed a technique for hip arthroscopy without a perineal post by which the patient is wrapped in a surgical beanbag, which is then taped to the bed to provide adequate countertraction. In addition, Mei-Dan et al.⁷ have described a technique of hip distraction without a perineal post by placing the surgical table in a 15° to 20° of Trendelenburg position; they have found friction and gravity to provide sufficient countertraction with this surgical setup. We similarly have relied on friction forces to provide countertraction in the case of contralateral amputation when a traction boot cannot be used. However, we have continued to use a perineal post for additional control and recommend against techniques that avoid a perineal post when an amputation of the nonsurgical leg is present. In these cases the post provides an added level of safety should the Coban-tape assembly unexpectedly fail when traction is applied.

Hip arthroscopy may be indicated and successfully performed in patients with lower-extremity amputations regardless of laterality, amputation level, or preference for mobilization using a wheelchair or prosthetic legs. Alternative patient positioning and joint distraction techniques are necessary, such as skeletal traction and temporary external fixation, for amputations ipsilateral to the surgical hip. We have described our experience with these techniques in combat-wounded veterans at our institution.

Supplementary Data

Video 1

Case example of arthroscopic management of left-hip combined-type femoroacetabular impingement in a 28-year-old patient with bilateral high transfemoral amputations. The patient was having groin pain while sitting in his wheelchair, as well as difficulty mobilizing with prostheses because of hip pain and gait disruption. He was secured to the fracture table with the contralateral limb supported by a well-leg holder. After a transosseous traction pin was placed in the ipsilateral subtrochanteric region, an external fixator was constructed and traction applied to the residual limb, allowing for adequate joint distraction and access to intra-articular structures. The patient underwent arthroscopic cam osteoplasty, acetabuloplasty, and labral repair by standard techniques. Representative images of the intra-articular and peripheral compartment pathology as viewed from the anterolateral portal with a 70° arthroscope are included.