Arthroscopy After Traumatic Hip Dislocation: A Systematic Review of Intra-articular Findings, Correlation With Magnetic Resonance Imaging and Computed Tomography, Treatments, and Outcomes

Femoroacetabular Variations Are Predisposing Factors for Traumatic Posterior Hip Dislocation

BACKGROUND

Although high-energy trauma mechanisms are generally considered to cause traumatic posterior hip dislocations, femoroacetabular variations are assumed to contribute to low-impact hip dislocations. Thus, the present study aimed to identify morphologic femoral and acetabular risk factors that may also contribute to posterior hip dislocations in high-energy trauma mechanisms.

METHODS

The acetabular and femoral morphology of 83 hips with a traumatic posterior dislocation following a high-energy trauma mechanism were analyzed and matched to a control group of 83 patients who sustained high-energy trauma without a hip injury. The lateral center-edge angle, acetabular index, acetabular depth/width ratio, cranial and central acetabular version angles, and the anterior and posterior acetabular sector angles were measured on computed tomography to quantify femoroacetabular impingement (FAI) morphology, acetabular version, and coverage. The caput-collum-diaphyseal angle and the alpha angles in the coronal and axial planes were measured to detect cam-type FAI deformity. A receiver operating characteristic curve was utilized to determine threshold values for an increased risk of hip dislocation.

RESULTS

Acetabular retroversion and posterior acetabular undercoverage were significantly increased in patients with hip dislocations compared with controls (p < 0.001). The central acetabular version angle and posterior acetabular sector angle that indicated an increased risk of hip dislocation were ≤9° and ≤90°, respectively. Cam-type FAI deformity and coxa valga were significantly increased in the dislocation group (p < 0.001). The anterolateral alpha angle that indicated an increased dislocation risk was ≥47°.

CONCLUSIONS

Acetabular retroversion, posterior acetabular undercoverage, and cam-type FAI morphology may be risk factors contributing to traumatic posterior hip dislocation in high-energy trauma mechanisms.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Surgical Technique: Arthroscopic Reduction and Fixation of Partial Posterior Wall Acetabular Fractures

Partial posterior wall fractures are usually fixed with open reduction-internal fixation through an open posterolateral approach, but when the fragment may be fixed without a plate (with screws only), reduction and fixation may also be achieved via hip arthroscopy with the patient in the prone position. This article presents all the surgical steps to perform this procedure.

Hip Capsulolabral Complex: Anatomy, Disease, MRI Features, and Postoperative Appearance

The hip is a uniquely constrained joint with critical static stability provided by the labrum, capsule and capsular ligaments, and ligamentum teres. The labrum is a fibrocartilaginous structure along the acetabular rim that encircles most of the femoral head. Labral tears are localized based on the clock-face method, which determines the extent of the tear while providing consistent terminology for reporting. Normal labral variants can mimic labral disease and can be differentiated by assessment of thickness or width, shape, borders, location, and associated abnormalities. The Lage and Czerny classification systems are currently the most well-known arthroscopic and imaging systems, respectively. Femoroacetabular impingement is a risk factor for development of labral tears and is classified according to bone dysmorphisms of the femur ("cam") or acetabulum ("pincer") or combinations of both (mixed). The capsule consists of longitudinal fibers reinforced by ligaments (iliofemoral, pubofemoral, ischiofemoral) and circular fibers. Capsular injuries occur secondary to hip dislocation or iatrogenically after capsulotomy. Capsular repair improves hip stability at the expense of capsular overtightening and inadvertent chondral injury. The ligamentum teres is situated between the acetabular notch and the fovea of the femoral head. Initially considered to be inconsequential, recent studies have recognized its role in hip rotational stability. Existing classification systems of ligamentum teres tears account for injury mechanism, arthroscopic findings, and treatment options. Injuries to the labrum, capsule, and ligamentum teres are implicated in symptoms of hip instability. The authors discuss the labrum, capsule, and ligamentum teres, highlighting their anatomy, pathologic conditions, MRI features, and postoperative appearance. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Clinical Outcomes and Associated Pathologies Following Pediatric Traumatic Hip Dislocations: A Systematic Review of the Literature

INTRODUCTION

Pediatric traumatic hip dislocations are a rare condition that can have devastating short and/or long-term outcomes and associated pathologies (APs), including associated injuries (AIs) and long-term adverse events (LTAEs), with negative long-term sequelae. Currently, there are little data that exist on the rate of APs, with the most notable being avascular necrosis (AVN), for pediatric traumatic hip dislocations. The purpose of this systematic review is to evaluate the outcome relative frequency of dislocation direction, reduction type, and rate of APs for traumatic hip dislocations in the pediatric population.

METHODS

A systematic review on the topic of traumatic hip dislocations in the pediatric population was performed using PubMed, ScienceDirect, Web of Science, CINAHL, and MEDLINE databases from database inception to March 30, 2023. Inclusion criteria was full-text English articles, addressed traumatic hip dislocations, and pediatric patients (<18 y old).

RESULTS

A total of 24 articles (n=575 patients) met final inclusion criteria from a total of 219 articles retrieved from the initial search. For the average age of the included patients with reported age (n=433 patients), the frequency weighted mean was 9.50 years±1.75 years with a frequency weighted mean follow-up time of 74.05 months ±45.97 months (n=399 patients). The most common dislocation direction was posterior (86.4%), the most common treatment type was closed reduction (84.5%), AVN was the most common type of LTAEs (15.5% of APs), and labral/capsular injuries and acetabular fractures were the most common type of AIs (14.0% and 9.4% of APs, respectively). There were a combined total of 414 APs (72%) out of 575 total patients.

CONCLUSION

Pediatric traumatic hip dislocations are associated with a high rate of AIs and LTAEs (72%, 414 APs out of 575 patients). AVN, labral/capsular injuries, and acetabular fractures are the most common APs after pediatric traumatic hip dislocations. Pediatric hip dislocations are usually posterior and commonly managed through closed reduction.

LEVEL OF EVIDENCE

III, Systematic Review.

Evaluating the utility of post-reduction imaging for simple hip joint dislocations: Is computed tomography always necessary?

Introduction

Following closed reduction of hip dislocations, computed tomography (CT) is considered standard of care to identify occult fractures or intra-articular loose bodies that may be missed on X-ray. The purpose of this study was to evaluate the sensitivity of post-reduction X-rays and the usefulness of subsequent post-reduction CT imaging.

Methods

All patients presenting to our hospital system for traumatic hip dislocations from 2013 to 2022 were retrospectively reviewed. Participants were included if they had a simple dislocation of a native hip, underwent closed reduction, and received post-reduction X-ray and CT imaging. A sensitivity analysis was performed for the detection of associated fractures and intraarticular loose bodies by post-reduction X-ray, using CT as a reference standard.

Results

Thirty-five subjects with a mean age of 26 years were included. Post-reduction CT revealed 6 fractures and 3 loose bodies, whereas post-reduction X-ray identified 3/6 (50%) fractures and 3/3 (100%) loose bodies. Four cases received operative management, all of which were identified by X-ray. Post-reduction X-ray had a sensitivity of 67% for identifying pathology that was subsequently found on CT, and a sensitivity of 100% for identifying pathology requiring surgery. Of the 13 cases with pre-reduction CT scans, none had new findings identified on post-reduction CT.

Conclusions

Post-reduction X-rays are effective in the evaluation of acute pathology associated with closed reduction of traumatic hip dislocations, especially for cases requiring operative management. Our findings suggest that if a fracture or loose body was not identified on post-reduction X-ray, a post-reduction CT added no value in surgical decision-making and was not necessary.

Effect of Vacuum Sealing Drainage on Soft Tissue Injury of Traumatic Fracture and Its Effect on Wound Recovery

Purpose

The current work is mainly to explore the effect of vacuum sealing drainage (VSD) on soft tissue injury (STI) caused by traumatic fractures (TFs) and its effect on wound recovery.

Methods

We first selected 90 patients with TF STI from May 2019 to May 2021, of which 40 patients (control group) received routine treatment, and the other 50 patients (observation group) were treated with VSD. The curative effect, rehabilitation (changing dressing frequency, healing time, and hospitalization time), pain severity, patient comfort, and complications were evaluated and compared.

Results

The observation group exhibited a higher total effective rate, lower dressing change frequency, complication rate, and shorter healing time and hospital stay than the control group, which are statistically significant. Statistically milder pain sensation and better patient comfort were also determined in the observation group.

Conclusions

VSD is effective and safe in the treatment of TF-induced sexually transmitted infections, which can effectively accelerate wound recovery while reducing pain sensation and improving patient comfort, with clinical promotion value.

Hip Dislocation and Subluxation in Athletes: A Systematic Review

BACKGROUND

Hip dislocation is a rare occurrence during sports but carries serious implications for athletes.

PURPOSE

To systematically review treatment strategies and outcomes for hip dislocation in athletes, with the ultimate goal of providing sports medicine physicians with the information necessary to appropriately treat and counsel patients sustaining this injury.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

PubMed, MEDLINE, and Embase were searched for studies relating to hip instability and athletics from January 1, 1989 to October 1, 2019. Abstracts and articles were evaluated on the basis of predefined inclusion and exclusion criteria. Inclusion criteria were the following: (1) data from ≥1 patients, (2) native hip dislocation or subluxation occurring during sports, (3) patients aged at least 10 years, and (4) written in English. Exclusion criteria were (1) patients younger than 10 years; (2) nonnative or postoperative hip dislocation or subluxation; (3) a native hip injury without dislocation or subluxation; (4) patients with dislocation or subluxation secondary to neuromuscular, developmental, or syndromic causes; (5) dislocation or subluxation not occurring during sports; (6) patients with physeal fractures; or (7) review articles or meta-analyses. Data were recorded on patient demographics, injury mechanism, treatment strategies, and clinical and radiographic outcomes. Where possible, pooled analysis was performed. Studies were grouped based on reported outcomes. Meta-analysis was then performed on these pooled subsets.

RESULTS

A total of 602 articles were initially identified, and after screening by 2 reviewers, 27 articles reporting on 145 patients were included in the final review. There were 2 studies that identified morphological differences between patients with posterior dislocation and controls, including decreased acetabular anteversion (P = .015 and .068, respectively), increased prevalence of a cam deformity (P < .0035), higher alpha angles (P≤ .0213), and decreased posterior acetabular coverage (P < .001). No differences were identified for the lateral center edge angle or Tonnis angle. Protected postreduction weightbearing was most commonly prescribed for 2 to 6 weeks, with 65% of reporting authors recommending touchdown, toe-touch, or crutch-assisted weightbearing. Recurrence was reported in 3% of cases. Overall, 4 studies reported on findings at hip arthroscopic surgery, including a 100% incidence of labral tears (n = 27; 4 studies), 92% incidence of chondral injuries, 20% incidence of capsular tears, and 84% incidence of ligamentum teres tears (n = 25; 2 studies). At final follow-up, 86% of patients reported no pain (n = 14; 12 studies), 87% reported a successful return to play (n = 39; 10 studies), and 11% had radiographic evidence of osteonecrosis (n = 38; 10 studies).

CONCLUSION

Various treatment strategies have been described in the literature, and multiple methods have yielded promising clinical and radiographic outcomes in patients with native hip dislocation sustained during sporting activity. Data support nonoperative treatment with protected weightbearing for hips with concentric reduction and without significant fractures and an operative intervention to obtain concentric reduction if unachievable by closed means alone. Imaging for osteonecrosis is recommended, with evidence suggesting 4- to 6-week magnetic resonance imaging and follow-up at 3 months for those with suspicious findings in the femoral head.

Minimally invasive removal of intra-articular hip fragments under navigation guidance

The interposition of foreign bodies between the femoral head and the acetabulum represents a danger to the articular cartilage with a definite progression to osteoarthritis. Their removal is necessary and usually involves two surgical techniques: by open arthrotomy or under arthroscopy. The present article proposes a new surgical technique allowing the removal of intra-articular foreign bodies from the hip by a minimally invasive approach and aCT-guided navigation system. This technique is a good alternative that overcomes some shortcomings of other minimally invasive techniques, which struggle to access the fragment. It can also avoid specific complications of these procedures, such as the risk of abdominal compartment syndrome with arthroscopy, in the case of an associated acetabulum fracture.

Traumatic Hip Dislocations in Major Trauma Patients: Epidemiology, Injury Mechanisms, and Concomitant Injuries

Introduction: Traumatic hip dislocations (THDs) are severe injuries associated with considerable morbidity. Delayed recognition of fracture dislocations and neurovascular deficits have been proposed to cause deleterious long-term clinical outcomes. Therefore, in this study, we aimed to identify characteristics of epidemiology, injury mechanisms, and associated injuries to identify patients at risk. Methods: For this study based on the TraumaRegister DGU^® (January 2002–December 2017), the inclusion criterion was an Injury Severity Score (ISS) ≥9 points. Exclusion criteria were an isolated head injury and early transfer to another hospital. The THD group was compared to a control group without hip dislocation. The ISS and New ISS were used for injury severity and the Abbreviated Injury Scale for associated injuries classification. Univariate and logistic regression analyses were performed. Results: The final study cohort comprised n = 170,934 major trauma patients. We identified 1359 individuals (0.8%) with THD; 12 patients had sustained bilateral hip dislocations. Patients with THD were predominantly male (79.5%, mean age 43 years, mean ISS 22.4 points). Aortic injuries (2.1% vs. 0.9%, p ≤ 0.001) were observed more frequently in the THD group. Among the predictors for THDs were specific injury mechanisms, including motor vehicle accidents (odds ratio (OR) 2.98, 95% confidence interval (CI) 2.57–3.45, p ≤ 0.001), motorcycle accidents (OR 1.99, 95% CI 1.66–2.39, p ≤ 0.001), and suicide attempts (OR 1.36, 95% CI 1.06–1.75, p = 0.016). Despite a lower rate of head injuries and a comparable level of care measured by trauma center admission, both intensive care unit and total hospital stay were prolonged in patients with THD. Conclusions: Since early diagnosis, as well as timely and sufficient treatment, of THDs are of high relevance for long-term outcomes of severely injured individuals, knowledge of patients at risk for this injury pattern is of utmost importance. THDs are frequently related to high-energy mechanisms and associated with severe concomitant injuries in major trauma patients.

Arthroscopic Treatment of Acetabular Rim Fracture after Traumatic Posterior Hip Dislocation: A Case Series Study

Objective

To investigate the clinical and radiographic short‐term results of arthroscopic treatment for posterior labrum tears with an attached bony fragment after traumatic posterior hip dislocation.

Methods

Between July 2014 and May 2019, a consecutive series of nine patients diagnosed with a posterior labrum tear with an attached bony fragment after traumatic posterior hip dislocation were treated by hip arthroscopic techniques. The patients had been injured in traffic accidents (n = 6) or high falls (n = 3). All patients were provided primary treatment at the emergency department of our institution, and then were transferred to our department for arthroscopy. Demographic data (e.g. gender, age, etc), intraoperative findings, the preoperative and postoperative multiple clinical scores and radiological results were subsequently assessed. Visual analogue scale for pain (VAS) and modified Harris hip scores (mHHSs) were measured and compared before surgery, and at the last follow‐up.

Results

A total of nine patients were enrolled, all of them were male, with a mean age at surgery of 32.2 ± 5.6 years (range, 22–65 years). The patients were followed‐up for an average of 26.5 ± 4.1 (range, 24 to 50 years). During the arthroscopic surgery, all patients had labral tears with posterior acetabular rim fracture. All patients had loose osteochondral fragments. Five had partial or complete tears of ligamentum teres. Two patients had osteochondral damage. Two had capsular rupture. Postoperative X‐ray films and three dimension computed tomography (3D‐CT) showed satisfactory reduction of posterior acetabular wall fractures. The mHHS before surgery and at 1 year and 2 years after surgery were 51.8 ± 4.3, 81.8 ± 2.0 and 87.5 ± 1.9 respectively; VAS scores were 5.6 ± 0.5, 1.3 ± 0.3 and 0.7 ± 0.3 respectively. As compared with the condition before surgery, there was a significant improvement in the mHHS and VAS scores at 1 year and 2 years after surgery (P < 0.01). There was no significant improvement in the mHHS and VAS scores between 1 year and 2 years after surgery (P < 0.05). At the final follow‐up, all patients had regained full range of motion (ROM) and were satisfied with the results. None of the patients showed signs of heterotopic ossification, avascular necrosis or progression of osteoarthritis of the hip joint.

Conclusion

Traumatic dislocation is accompanied by a variety of intra‐articular hip joint pathologies. Managing posterior acetabular rim fracture after traumatic posterior hip dislocation using arthroscopic reduction and fixation with anchors is a safe and minimally invasive option and delays the progression of traumatic osteoarthritis.

Indications and Outcomes After Ligamentum Teres Reconstruction: A Systematic Review

Purpose

To systematically review the literature to better understand the current indications for ligamentum teres reconstruction (LTR), current graft and acetabular fixation options used, patient-reported outcomes after LTR, and incidence of complications and reoperations after LTR.

Methods

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. All literature related to LTR published prior to July 2020 was identified. The inclusion criteria consisted of investigations reporting on human patients with pathology of the ligamentum teres who underwent LTR, including mentions of the indications, graft type, acetabular fixation method, postoperative patient-reported outcome scores, and incidence of complications and reoperations.

Results

Seven studies comprising 26 patients (28 hips) were included. The most commonly reported indication for LTR was persistent pain and instability after failed prior hip arthroscopy (68%, 19 of 28 hips). The mean postoperative modified Harris Hip Score, Non-arthritic Hip Score, and visual analog scale score all showed improvement when compared with preoperative values. A total of 2 complications occurred. Complication rates ranged from 0% to 100% in included case reports and 0% to 11% in included case series. A total of 9 reoperations were performed. Reoperation rates ranged from 0% to 100% for case reports and 18% to 100% for case series. Reoperation rates ranged from 33% to 100% in studies with patients receiving acetabular fixation using anchors versus 0% to 22% in studies performing LTR with buttons. Reoperation rates in athletic patients and patients with Ehlers-Danlos syndrome ranged from 0% to 100% and 0% to 50%, respectively.

Conclusions

The main indication for LTR was persistent hip or groin pain and instability after a prior hip arthroscopy. The short-term postoperative modified Harris Hip Score, Non-arthritic Hip Score, and visual analog scale score after LTR showed favorable outcomes. However, reoperations after LTR were not uncommon.

Level of Evidence

Level V, systematic review of Level IV and V studies.

Hip Instability in the Athlete: Anatomy, Etiology, and Management

In this review, the recent literature evaluating the anatomic considerations, etiology, and management options for athletes with hip instability are investigated. Studies on the osseous, chondrolabral capsuloligamentous, and dynamic muscular contributions to hip stability are highlighted. Microinstability, iatrogenic instability, and femoroacetabular impingement-induced instability are discussed with a focus on demographic and outcomes research in athletes. Surgical techniques including both open and arthroscopic approaches are additionally evaluated.

Role of arthroscopy for the diagnosis and management of post-traumatic hip pain: a prospective study

The current published literature regarding the role of hip arthroscopy in the diagnosis and management of post-traumatic hip pain is still limited. Therefore, we conducted the present prospective study to determine the value of hip arthroscopy in the diagnosis and management of various causes of hip pain after traumatic conditions. The present study included a prospective cohort of 17 patients with symptomatic post-traumatic hip pain. It was conducted between July 2013 and May 2018. The mean age was 22 (19-29) years and the mean follow-up was 24 (r: 7-36) months. Prior to surgery, every eligible patient underwent assessment of functional status using the Modified Harris Hip Score, Oxford hip score (OHS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. All patients underwent arthroscopic management for their diagnosed pathologies. The most commonly encountered diagnosis was labral tear (58.8%), followed by ligamentum teres tear (35.3%) and loose intra-articular fragments (29.4%). In addition, 52.9% of the patients had associated CAM lesion and 11.8% had associated Pincer lesion. The mHSS, OHS and WOMAC score showed significant improvement in the post-operative period (P < 0.001), all the 17 patients had 100% Patient Acceptable Symptomatic State; only one patient did not achieve minimal clinical importance difference. One case underwent labral debridement for failed labral repair (5.8%), another patient developed maralgia paraesthetica (5.8%). In conclusion, hip arthroscopy is a useful and effective minimally invasive procedure for the diagnosis and management of selected patients with post-traumatic hip pain. Moreover, hip arthroscopy was safe technique with no reported serious adverse events.

CLINICAL RELEVANCE of the LIGAMENTUM TERES: A LITERATURE REVIEW

Background

The ligamentum teres (LT) continues to be a structure of debate and interest. Previously thought of as a vestigial structure, an awareness of LT pathology and its potential importance has increased with the expansion of hip arthroscopy.

Purpose

To provide a comprehensive literature synthesis on the LT and provide clinicians with the most current research regarding the LT and its anatomical features, functional relevance, prevalence of injury, risk factors for injury, clinical presentation, and treatment for pathology.

Methods

A systematic literature search was conducted using Medline/PubMed, CINAHL/EBSCO, and Cochrane/Wiley databases/platforms using the following search terms: ligament, ligament teres, hip, femur, femoral head, round ligament.

Results

This search yielded 1284 articles of which 44 met the inclusion/exclusion criteria and contributed to this manuscript. Information on the LT was summarized into the following areas: anatomy, function, injury prevalence, risk factors, mechanism of injury, duration of symptoms, clinical presentation (symptoms, range of motion, functional limitations, special testing), imaging, and treatment.

Conclusions

The results of this review supported the following: 1) the LT has a function in restraining hip rotation range of motion; 2) the prevalence of LT pathology in any given population may be largely dependent on the severity of bony deformity (either femoroacetabular impingement(FAI) or dyplasia) and activity level; 3) older age and acetabular bony deformity (either FAI or dyplasia) are risk factors for generalized LT pathology; 4) unique signs and symptoms are difficult to identify because LT pathology rarely occurs in isolation and is likely the end-stage consequence of other hip pathology; 5) the presence of LT pathology may negatively affect an individual's ability to function; and 6) surgical debridement is recommend for pain relief of partial LT tears with reconstruction possible for complete LT tears when complaints of instability are noted.

Level of Evidence

3.

A Systematic Summary of Systematic Reviews on the Topic of Hip Arthroscopic Surgery

BACKGROUND

There is a rapidly growing body of literature on the topic of hip arthroscopic surgery.

PURPOSE

To provide an overall summary of systematic reviews published on the indications, complications, techniques, outcomes, and information related to hip arthroscopic surgery.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of all hip arthroscopic surgery-related systematic reviews published between January 2000 and May 2018 was performed using PubMed, MEDLINE, and the Cochrane Library. Narrative reviews and non-English articles were excluded.

RESULTS

A total of 837 articles were found, of which 85 met the inclusion criteria. Included articles were summarized and divided into 6 major categories based on the subject of the review: femoroacetabular impingement (FAI), non-FAI indications, surgical technique, outcomes, complications, and miscellaneous.

CONCLUSION

A summary of systematic reviews on hip arthroscopic surgery can provide surgeons with a single source for the most current synopsis of the available literature. As the prevalence of orthopaedic surgeons performing hip arthroscopic surgery increases, updated evidence-based guidelines must likewise be advanced and understood to ensure optimal patient management.

Is It Safe to Perform an Early Arthroscopy After a Traumatic Hip Dislocation With an Associated Pelvic Ring Injury? Report of Our Technique

Hip arthroscopy is useful in the treatment of several intra-articular pathologies, however, its use in high-energy hip and pelvis injuries raises concerns about fluid extravasion and stability of the pelvic ring. We present our arthroscopic surgical technique (initial access to the peripheral compartment) to remove intra-articular loose bodies and treat associated lesions, as well as our concerns with the technique, in case of a traumatic hip dislocation associated with a contralateral pelvic ring injury.

Editorial Commentary: Safe Innovation? Arthroscopy After Traumatic Hip Dislocation

Hip arthroscopy can be helpful relative to conventional imaging when diagnosing (and treating) intra-articular injuries after a hip dislocation, but more evidence is required before adopting this approach diagnostic and therapeutic strategy.