Introduction

Hip arthroscopy has been described as part of treatment regimens for hip trauma and related sequelae for decades, but the role of hip arthroscopy for this application has expanded rapidly during recent years. As early as 1931, Burman noted a role for a form of hip arthroscopy for loose body or fragment removal. The role for surgical debridement of the hip expanded substantially with the observation that loose bodies were ubiquitous with hip fracture dislocations. Epstein advised that all hip fracture–dislocations should be treated with debridement in an attempt to delay the appearance of traumatic arthritis and to minimize its severity. He advocated open debridement rather than arthroscopic debridement. The prevalence of loose bodies after injury to the hip and their impact on the development of hip joint arthrosis certainly contributed to the imperfect long-term results of dislocations and fractures around the hip joint (Figures 24-1 and 24-2). Until recently, loose bone and cartilage fragments were almost always retrieved with open arthrotomy. Advances in arthroscopic tools and techniques have made arthroscopic loose-body removal highly efficient. Arthroscopy advantages include diminished blood loss, smaller incisions, decreased recovery time, reduced potential for neurovascular damage, and decreased disruption of capsuloligamentous structures. Indications for arthroscopic debridement after trauma have been extended to include the extraction of bullets, the removal of broken hardware from the joint, and joint lavage for the treatment of infection or contamination in association with bullet fragments passing through the bowel and communicating with the hip joint.

Figure 24–1 A 31-year-old male who sustained a femoral head fracture and hip dislocation that were treated with open reduction and internal fixation 6 months earlier. Persistent groin pain was relieved with intra-articular anesthetic. A hypertrophied and inflamed labrum is evident.

Figure 24–2 Another view of the same patient shown in Figure 24-1. Femoral head chondrolysis is evident. Intervention was limited to labral debridement, chondroplasty of the femoral head, and lavage.

The arthroscopic treatment of acetabular labral pathology most typically involves atraumatic tears or labral disease associated with impingement or hip dysplasia. Isolated cases of traumatic labral pathology have been reported since 1959, when Dameron described a bucket-handle tear of the acetabular labrum that prohibited the reduction of a posterior dislocation of the hip that subsequently required open repair. Labral injury has more recently been described as a relatively common but previously poorly recognized phenomenon in association with acetabular fractures. Ganz described reproducible labral pathology in 14 patients with displaced transverse acetabular fractures who had been treated with open reduction and internal fixation. The labrum was partially or completely detached from the superior acetabular rim in all cases. In this series, an avulsed portion of the labrum was left if it was stable and undamaged, resected if it was unstable and damaged, and repaired if it was unstable but intact or attached to a bony fragment. Ganz proposed arthrotomy at the time of acetabular fracture fixation to search for associated intracapsular injuries in displaced transverse acetabular fractures and to treat injuries accordingly. In the case of acetabular fractures, multiple authors have identified reduction as the most important factor for avoiding the development of arthrosis and for obtaining a good clinical outcome, but they have noted that even anatomic fracture reduction fails to guarantee excellent outcomes. It is likely that additional factors such as chondral damage at the time of injury, loose fragments, and labral injuries all contribute to the patient’s final long-term outcome (Figures 24-3 and 24-4).

Figure 24–3 A 28-year-old female who sustained a displaced both-column acetabular fracture at the age of 19 years. She had a gradual onset of groin pain over the previous year, with nonspecific findings of magnetic resonance imaging and pain relief with intra-articular anesthetic injection. Extensive fibrillation and cartilage loss on the femoral head are seen.

Figure 24–4 Another view of the same patient shown in Figure 24-3. There is a small anterior labral tear. The labral tear and the femoral head were debrided.

Indications

Brief history and physical examination

Patients with high-energy trauma require more urgent and comprehensive treatment than patients who have experienced lower-energy or focal trauma to the hip. The initial evaluation of a patient with high-energy trauma is based on the Advanced Trauma Life Support protocol and includes the “ABCs”—airway, breathing, and circulation—of the primary survey. The treatment of high-energy trauma patients is directed by general surgical colleagues with prompt cooperation from orthopedic surgeons. Standard radiographic trauma series include an anteroposterior pelvic radiograph, an anteroposterior chest radiograph, and a lateral cervical spine radiograph. The orthopedic examination includes the palpation of the spine and all extremities to look for crepitance, deformity, open injuries, and dislocation. A high index of suspicion for a posterior hip dislocation is maintained when a patient presents with a shortened extremity with the affected hip held in flexion, abduction, and internal rotation. Alternatively, an anterior dislocation leaves the hip in extension and neutral or slight abduction. The examiner must complete a thorough trauma evaluation, because 95% of patients with a hip dislocation have at least one other organ-system injury. Of the patients who have high-energy hip dislocations, 15% have abdominal injuries, 21% have thoracic injuries, 21% have craniofacial injuries, 24% have closed head injuries, and 33% have other orthopedic injuries.

Imaging and diagnostic studies

An anteroposterior pelvic radiograph is a routine part of the evaluation of a traumatically injured patient. If there is a disruption of the anterior or posterior pelvic ring, then the evaluation routinely includes pelvic inlet and outlet views. Similarly, if an associated acetabular fracture is present or suspected, radiographic evaluation should include the 45-degree oblique views described by Judet and Letournel. The closed reduction of a dislocated hip must be confirmed by a repeat anteroposterior pelvic radiograph. Follow up studies should also include pelvic computed tomography (CT) scans with 1.5-mm cuts through the acetabulum to search for loose bodies, to assess acetabular fractures, and to evaluate the reduction status of associated femoral head fractures. Final complete radiographs should include a dedicated hip series as well as full-length views of the ipsilateral femur to evaluate for associated fractures. In the case of gunshot wounds, metallic markers should be placed at all identifiable entrance and exit wounds to facilitate an understanding of the bullet’s trajectory. Radiographs and CT scans may not reliably demonstrate loose bodies within the hip joint. In a series of 36 patients who were treated with arthroscopy, Mullis and Dahners found loose bodies in 33 patients, including 7 out of 9 patients who had no loose bodies seen on preoperative radiographs or CT scans with 3-mm cuts.

Labral tears are best evaluated with magnetic resonance arthrography. Typically, labral tears associated with high-energy trauma have not been routinely addressed or even recognized acutely unless they are specifically sought intraoperatively during open fracture fixation. Thus, magnetic resonance arthrograms may be most frequently indicated for traumatically injured patients who continue to have unexplained pain during convalescence. Labral injuries have been demonstrated in association with acetabular fractures, and traumatic labral pathologies should be addressed. The extent to which minor labral injuries associated with high-energy trauma will become symptomatic or contribute to arthrosis remains unknown.

Surgical technique

The patient can be placed supine or in a lateral position, depending on surgeon preference. Because one must take into consideration other injuries of the traumatized patient (e.g., spine injury) when positioning him or her, a supine position is often required. By contrast, an obese patient’s pannus may interfere with the maneuverability of arthroscopic equipment if he or she is in the supine position, so a lateral position should be considered for these individuals. A standard fracture table or a custom distraction device is necessary to distract the joint space. In our practice, we prefer to use a commercially available distraction device system that accommodates hip arthroscopy. Distractor systems must possess a stable distraction mechanism and a well-padded perineal post; most described complications encountered with hip arthroscopy are neuropraxias caused by compression against an underpadded post or by distraction, especially if it is prolonged. In addition, the perineal post must be offset laterally against the medial thigh of the operative leg to achieve a sufficient vector to distract the hip joint. The hip is slightly abducted and flexed to relax the anterior hip capsule. Both feet are generously padded and securely placed into the foot holders. Fluoroscopy is introduced from the nonoperative side of the patient before the sterile preparation of the injured extremity to confirm the ability to distract the joint. Approximately 50 lb of traction is needed to distract the hip joint; however, less force may be needed for the distraction of recently injured hips with traumatic capsular disruptions.