2.21 Late acetabular reconstruction

10.1055/b-0035-121673

2.21 Late acetabular reconstruction

Manyi Wang, Xinbao Wu, Shiwen Zhu

1 Introduction

Letournel and Judet [1] divided acetabular fracture surgery into three categories based on time of injury: within 3 weeks (21 days), 3 weeks to 4 months, and longer than 4 months. Surgery performed 3 weeks after fracture is significantly more difficult because of the amount of soft-tissue scarring around the fracture site [2]. If surgery is performed more than 4 months after fracture, formation of scar tissue and callus and other anatomical challenges adversely affect the quality of reconstruction. In addition, patient prognosis at this time usually is poor [3].

Delayed acetabular reconstruction is associated with many challenges. Because of the well-established network of trauma centers in developed countries, treatment of acetabular fractures is now seldom delayed. Among developing countries these networks are improving; therefore, most acetabular fractures can be treated early. Thus, the experience of delayed treatment for acetabular fractures is becoming a lost skill. The current literature lacks robust evidence to show that delayed operative care is effective, so there is no consensus on the best treatment options for the neglected acetabular fracture.

The prognosis mainly depends on factors, such as the quality of reduction, patient age, concomitant femoral head injury, sciatic nerve palsy, postoperative heterotopic ossification (HO), and osteonecrosis of the femoral head [2–5]. Surgical delay also plays an important role [6–9]. Johnson et al [3] reported that anatomical reduction was achieved in only 52% of patients who underwent surgery 21 days after injury. Deo et al [9] summarized the experience of 1,266 patients from multiple centers between 1991 and 2006, reporting that satisfactory reduction was difficult to achieve if the interval between injury and surgery was more than 11 days. Kumar et al [8] summarized 73 consecutive cases of acetabular fractures and found that the hip function in the group treated more than 2 weeks after injury was lower than that of those treated within 2 weeks but the difference was not statistically significant. Deo et al [9] reported that 91% of patients with excellent or good function had surgery within 14 days, and in 78% of patients with fair function, surgery had been delayed for more than 14 days. Among the 161 patients followed up by Briffa et al [10], more than half who had surgery 8.4 days following injury had a poor result.

2 Indications

Johnson et al [3] reviewed 207 acetabular fractures for which treatment was delayed and concluded that despite difficulties associated with this delay, the results were more encouraging than first believed. They reported a significant rate (65.5%) of good to excellent results. Delayed surgical treatment has been reported to be more beneficial than nonoperative treatment in cases of severe fracture displacement, young age, and a timeframe between injury and treatment of less than 120 days [2]. Careful preoperative planning and adequate surgeon experience are essential factors.

Even for delayed acetabular fracture the value of other reconstructive techniques should not be forgotten. Total hip arthroplasty (THA) has been proven to be a successful definitive treatment for patients with posttraumatic osteoarthritis after acetabular fracture. Previous open reduction and internal fixation, however, can affect the results of late THA. Ranawat et al [11] concluded that abnormal anatomical structure after acetabular fracture usually is responsible for subsequent THA failure. Lai et al [12] reported a positive relationship between anatomical restoration of the hip center and primary fracture treatment, but not fracture pattern in patients who underwent late THA following acetabular fracture. Bony defect was present in 32% of the ORIF group while 67% was noted in the conservative group.

Both malunion with obvious displacement and nonunion should be considered indications for late reconstruction or revision surgery. Acetabular nonunion tends to occur in transverse fractures and its associated patterns [3, 13]. Clinically, pain and clicking (ie, bony crepitus due to nonunion), physical examination, and review of x-rays and computed tomographic (CT) images will confirm the diagnosis.

3 Surgical treatment: potential problems

As with all surgical treatments the surgeon must be aware of the potential problems when planning and executing a difficult surgical procedure. Irregular anatomical morphology, soft-tissue contracture, HO, acetabular defect, and retained metal are potential problems that the surgeon must consider in the preoperative planning. These problems make the surgical exposure and scar tissue release more challenging. Moreover, the anatomical landmarks become indistinguishable because of callus formation and scar tissue surrounding the fracture site. This fact makes the ability to achieve an anatomical reduction difficult. All these problems result in the following: significant prolong surgical time, increase intraoperative blood loss, postoperative hematoma formation resulting in an increased risk of infection, a complicated postoperative and rehabilitation course, and possibly increased patient mortality.

4 Surgical algorithm

The aim of delayed surgical management for acetabular fractures is the same as for immediate management: to reconstruct the articular surface, stabilize fracture fragments, restore hip range of motion, and relieve pain.

For acetabular fractures in which treatment occurs within 120 days from injury, well-identified indications and a carefully selected surgical plan helps to achieve satisfactory reduction, which usually leads to relatively satisfactory results. However, be cautious when considering open reduction techniques for patients in whom management has been delayed for more than 120 days [14]. The patient must know the limitations of the surgical treatment and the surgeon must understand the limitations of what can be achieved with this type of care. After a thorough and intense study of the x-rays and understanding what is the agreed outcome for both patient and surgeon, the surgeon will develop a preoperative plan outlining what can be achieved and by what techniques.

4.1 Approach

Solid knowledge of acetabular anatomy and experience with all available approaches are essential for late reconstruction of the acetabulum. Along with the traditional ilioinguinal and Kocher-Langenbeck approaches, the combined anteroposterior approach is often used. For patients with severe contracture and significantly displaced fracture malunion, an extended Kocher-Langenbeck or triradiate approach may be required [13], and intraoperative trochanteric osteotomy or surgical hip dislocation may improve access to the acetabulum [15].

Delayed surgical management for acetabular fractures differs radically from that for diaphyseal fractures. To achieve satisfactory reduction of acetabular fractures, a combined approach typically is required to fully expose the fracture site, which inevitably increases surgical risks. Osteotomy is sometimes necessary for patients with severe fracture malunion.

The primary fracture type mostly drives the surgical approach for delayed management. For both-column fractures, a combined approach is recommended. For simple fracture types, such as posterior column, posterior wall, and posterior column plus posterior wall, the Kocher-Langenbeck approach accommodates both the reduction and fixation procedures; however, for patients with severe soft-tissue contracture, trochanteric osteotomy may be required for adequate exposure. Use of a prone position improves visualization of the exposure for both the surgeon and the assistant, simplifying the operation, whereas use of the lateral decubitus position should be considered in the event that intraoperative hip dislocation is necessary for reduction of the joint. The ilioinguinal approach can be used for anterior column and anterior wall fractures; however, these two fracture types are seldom encountered in delayed management. Johnson et al [3] reported on 188 patients who underwent delayed treatment of acetabular fracture; only 9 (< 5%) had anterior column and anterior wall fractures.

The extended iliofemoral approach that was first introduced by Letournel [1] has been recommended for delayed reconstructions of many complex fracture patterns particularly where an intraarticular reduction is anticipated [3]. Mayo et al [16] reported that in 23% of patients undergoing revision of acetabular fracture, the extended iliofemoral approach was used. This approach has met with some resistance because of adverse events such as infection, joint stiffness, abductor weakness, and HO [17–20].

Some authors [21, 22] argued that the combined approach offers more advantages for delayed treatment of complex acetabular fractures. The combined approach preserves the abductor muscle and provides simultaneous anterior and posterior reduction and fixation. The authors also pointed out the drawbacks of this approach, which include the need for two teams of surgeons, prolonged operating time, and increased blood loss.

Wang et al [2] proposed “floating” the patient between prone and supine on the operating table when using a combined approach. In this situation the patient can be switched between positions, which require only one team to perform the operation. This approach also provides better intraoperative visualization to ensure thorough release of both anterior and posterior scar tissue. The quality of the reduction is improved by an operation performed from both anterior and posterior sides. Thus, the most common approaches for delayed reconstruction will be either the combined approach or the extended iliofemoral approach.

4.2 Surgical technique

Interfragmentary release is the key for delayed treatment of acetabular fractures. Review of preoperative imaging studies helps distinguish the relationship between callus and normal bone. Intraoperatively, soft tissue and callus must be cleared until the fracture line is identified, after which the fragments can be gradually released and reduced to their original anatomical position.

For column fractures, the fracture gap must be cleared of interpositional scar tissue, callus, and surrounding soft tissue. With posterior column fractures ( Fig 2.21-1 ), malrotation usually is difficult to correct because of contracture of the sacrotuberous and sacral spine ligaments. Use of the Kocher-Langenbeck approach with trochanteric osteotomy expands the exposure range by rotating the abductors and the vastus lateralis muscle flap anteriorly to protect the hip capsule and soft-tissue attachment on the posterior wall fracture fragment. These soft-tissue attachments will also help in determining the correct position of these fragments.

In severe malunions, an osteotomy along the healed original fracture site is required for reduction. Extraarticular osteotomy is used to correct malrotation, angulation, and shortening deformities, whereas intraarticular osteotomy with preservation of the cartilage is primarily used to achieve anatomical reduction of the articular surface. For example, treatment of an acetabular fracture in a patient with a pelvic injury was delayed for 8 months because a life-saving treatment was required for a severe abdominal injury. A combined approach consisting of intraarticular and extraarticular osteotomy was used, with excellent results at follow-up ( Fig 2.21-2 ).

**Fig 2.21-1a–e** A 26-year-old woman was involved in a traffic injury while 8 months pregnant. To avoid radiation damage to the fetus, she refused x-ray examination until 5 months after injury. a The delayed posterior column fracture associated with femoral head dislocation was confirmed when she was sent to our institution. b During surgery the scar tissue inside the acetabular fossa was cleaned, the sacrotuberous and sacral spine ligament were released until the posterior column was freely mobile. **c–e** AP pelvis and Judet x-rays demonstrating an almost anatomical reduction.

For posterior wall defects, THA should be considered for older patients with damage to the weight-bearing surface of the femoral head. For young, active patients with no damage to the femoral head, the posterior wall can be reconstructed using autograft harvested from the posterior superior iliac crest ( Fig 2.21-3 ).

Both-column fractures often require simultaneous anterior and posterior exposure. For delayed acetabular fracture surgery, the most difficult step is to determine and correct rotational displacement. Simultaneous anterior and posterior exposure via extended iliofemoral or combined approach allows for a comprehensive release, simplifying intraoperative management compared with use of a single ilioinguinal or Kocher-Langenbeck approach. With the combined approach and the floating position, preoperative sterilization and draping are performed only once and the patient’s position can be changed intraoperatively at the surgeon’s convenience. For example, this both-column fracture of previous fixation failure was successfully revised via a combined approach ( Fig 2.21-4 ). For delayed treatment of acetabular fracture associated with pelvic injury, the advantages of a combined approach are greater: simultaneous exposure of the pubic symphysis and acetabular fragments, complete release, and simplified reduction and fixation ( Fig 2.21-5 ).

Only gold members can continue reading. Log In or Register to continue