Imaging evaluation of the hip after arthroscopic surgery for femoroacetabular impingement

Particularities on Anatomy and Normal Postsurgical Appearances of the Hip

Detailed knowledge of anatomy helps to understand pathologic processes. This article focuses on the anatomy and functionality of the hip, with emphasis on recently studied concepts and anatomic features that have an association with the development of symptoms. The most common anatomic variants posing a challenge for diagnosis and other common findings in asymptomatic patients are reviewed. Good understanding of the different surgical procedures helps in providing as much information as possible to guarantee a favorable outcome, improving prognosis. We review what are the commonly expected postsurgical appearances and the most common postsurgical complications.

The incidence and pattern of iliopsoas tendinitis following hip arthroscopy

BACKGROUND

Iliopsoas tendinitis is a known source of extra-articular hip pain and it has been shown to be a common cause of continued hip pain following total hip arthroplasty. While iliopsoas tendinitis after hip arthroscopy is a well-known phenomenon amongst hip arthroscopists, its presentation, course, and treatment has yet to be elucidated.

METHODS

An IRB-approved chart review was performed of patients undergoing hip arthroscopy for femoroacetabular impingement (FAI) between March 2015 and July 2017. No cases of dysplasia were included. All patients had combined cam/pincer impingement as well as labral pathology. Tendinitis patients were identified. Patient demographics, surgical data, time to onset/diagnosis of iliopsoas tendinitis, treatment (oral anti-inflammatories, corticosteroid injection, physical therapy), and resolution of symptoms were recorded. These cases were age- and sex-matched to a control group that did not develop postoperative iliopsoas tendinitis for comparison. Patient outcomes were measured with the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS) recorded from the preoperative and 1-year postoperative visits.

RESULTS

Of 258 hip arthroscopy cases, 18 cases (7.0%) of postoperative iliopsoas tendinitis were diagnosed under high resolution ultrasound. On average, iliopsoas tendinitis was diagnosed 2.8 ± 1.8 months after surgery. There were no significant differences in age, sex, and BMI between patients that developed IP tendinitis compared to those that did not. No specific procedures were found to be significantly associated with incidence of postoperative IP tendinitis, including capsular closure.18 patients were treated with corticosteroid injection, which provided mild to moderate improvement for 5 (27.8%) patients and completely resolved symptoms for 13 patients (72.2%). Of all 18 patients with postoperative iliopsoas tendinitis confirmed by response to a diagnostic injection, 10 (55.6%) had symptoms improve within 3 months of diagnosis, 2 (11.1%) between 3 and 6 months, 4 (22.2%) between 6 and 12 months, and 2 (11.1%) after 1 year. No patients went on to have surgery for this problem. Patients with iliopsoas tendinitis had lower MHHS (p = 0.04) and NAHS (p = 0.09) scores at their 1-year postoperative visits.

CONCLUSIONS

Iliopsoas tendinitis is a common source of pain following arthroscopic hip surgery and can be effectively diagnosed and treated with ultrasound-guided injection. Therefore, surgeons performing arthroscopic procedures of the hip must remain aware of and include it in their differential when encountering patients with hip flexion pain after surgery. Research should be continued to further evaluate the long-term outcomes and return to sport rates of these patients.

Approach to a Failed Hip Arthroscopy

PURPOSE OF REVIEW

Hip arthroscopy has seen increasing utilization over the last decade. This is largely related to increased recognition and improved techniques for treating femoroacetabilar impingement (FAI). Though hip arthroscopy generally yields favorable outcomes, there are a subset of patients who have residual or recurrent symptoms that require reoperation. The current review discusses an algorithmic approach to evaluating patients following a failed hip arthroscopy including a framework for clinical and radiographic assessment, available treatment options, and associated outcomes in revision surgery.

RECENT FINDINGS

Residual FAI has been demonstrated to be the most common indication for revision arthroscopy. Other indications include residual or recurrent labral pathology, gross instability, microinstability, or adhesions. Appropriate history and imaging are important to determine the cause for residual symptoms. Novel techniques including labral and capsular reconstruction, and modified remplissage procedures have been developed to deal with complex revision cases. Though studies have shown improved outcomes after revision surgery, they have been shown to result in inferior outcomes compared to a matched cohort following primary hip arthroscopy. Management of a failed hip arthroscopy remains a complex problem. Focused history, cross-sectional imaging, and revision hip arthroscopy with novel techniques can improve outcomes, albeit to a lesser extent than patients undergoing successful primary hip arthroscopy. The information provided here can help guide treatment and set appropriate patient expectations for revision surgery.

Understanding a Rare Injury: An Observational Study of Anterior-Superior Hip Dislocations

OBJECTIVE. The goals of this study were to assess the prevalence of anterior hip dislocation and to highlight the distinctive imaging features of anterior-superior hip dislocation. MATERIALS AND METHODS. A retrospective chart review was conducted of all hip dislocations seen at one university hospital from January 2005 to January 2019. The radiology database was queried for all reports of hip or pelvis radiographs with the word "dislocation." Cases of developmental dysplasia of the hip, infection, tumor, arthroplasty, Girdlestone procedure, surgical dislocation, and prior hip surgery were excluded, leaving 237 traumatic hip dislocations. Electronic medical records of the 18 cases of anterior hip dislocation were reviewed to determine the mechanism of injury, treatment, and subsequent outcomes. RESULTS. Among 237 traumatic hip dislocations, 18 (7.6%) were anterior hip dislocations. Among the 18 were three (17%) anterior-superior dislocations and 15 (83%) anterior-inferior dislocations. All anterior-superior dislocations had poor outcomes. One patient had persistent hip pain and instability and underwent follow-up imaging. In one case, MRI performed at the time of injury and 11 months later showed tears of the superior capsule, iliofemoral ligament, and ligamentum teres. The iliofemoral ligament tear did not heal, resulting in a persistent anterior capsule defect, a finding previously associated with instability in patients who have undergone arthroscopic surgery. CONCLUSION. The incidence of anterior hip dislocation was lower than some studies have suggested. Anterior-superior hip dislocation is a rare injury in which ligamentous defects are visualized at MRI and possibly contribute to anterior hip instability and pain.

Refractory pain following hip arthroscopy: evaluation and management

With increased knowledge and understanding of hip pathology, hip arthroscopy is rapidly becoming a popular treatment option for young patients with hip pain. Despite improved clinical and radiographic outcomes with arthroscopic treatment, some patients may have ongoing pain and less than satisfactory outcomes. While the reasons leading to failed hip arthroscopy are multifactorial, patient selection, surgical technique and rehabilitation all play a role. Patients with failed hip arthroscopy should undergo a thorough history and physical examination, as well as indicated imaging. A treatment plan should then be developed based on pertinent findings from the workup and in conjunction with the patient. Depending on the etiology of failed hip arthroscopy, management may be nonsurgical or surgical, which may include revision arthroscopic or open surgery, periacetabular osteotomy or joint arthroplasty. Revision surgery may be appropriate in settings including, but not limited to, incompletely treated femoroacetabular impingement, postoperative adhesions, heterotopic ossification, instability, hip dysplasia or advanced degeneration.