Dislocation After Hip Arthroscopy for Cam-Type Femoroacetabular Impingement Leading to Progressive Arthritis: A Case Report

Late post-arthroscopy hip instability. Diagnosis, treatment, and 5-year follow-up: A case report

INTRODUCTION

Hip instability following arthroscopy is a rare complication with a clinical spectrum ranging from gross dislocation (macro-instability) to micro-instability, characterized by pain and limitation for daily activities. Therefore, it should be considered as a potential differential diagnosis in patients experiencing persistent pain after hip arthroscopy.

CASE PRESENTATION

A 41-year-old male presented with a history of anterior hip dislocation and macro-instability symptoms three years post-hip arthroscopy. Magnetic resonance imaging (MRI) revealed a disruption of the anterior hip capsule. The patient initiated physiotherapy and resumed activities, but ten months later, experienced another anterior dislocation. Pain and apprehension during external hip rotation were evident. Three-dimensional computed tomography (CT) indicated irregularities in the anterior and superior margin of the acetabulum, while MRI arthrogram showed a rupture of the anterior capsule and deficiency in the anterior hip ligaments. Open reconstruction of the anterior capsule was performed, resulting in favorable progression over the 5-year follow-up.

DISCUSSION

This case highlights post-arthroscopy hip instability with a delayed presentation, possibly linked to chronic anterior capsule deficiency and inadequate acetabular coverage. Primary capsule repair after hip arthroscopy has proven effective in reducing the occurrence of instability symptoms and reoperations.

CONCLUSIONS

Post-arthroscopic hip instability may manifest immediately after surgery or several years later. Open reconstruction of the anterior capsule emerges as a successful strategy for addressing this complication, demonstrating satisfactory outcomes in a 5-year follow-up.

Patient-Specific Risk Factors Exist for Hip Fractures After Arthroscopic Femoroacetabular Impingement Surgery, But Not for Dislocation—An Analysis of More Than 25,000 Hip Arthroscopies

Purpose

To identify postoperative complications and risk factors associated with hip fracture and dislocation following primary arthroscopic surgical management of femoroacetabular impingement (FAI) syndrome.

Methods

MarketScan was queried to identify patients who underwent FAI surgery from 2007 to 2016. Patients were stratified into 2 groups: acetabuloplasty only or femoroplasty only. A subanalysis of combined acetabuloplasty and femoroplasty also was undertaken. Surgical outcomes were followed postoperatively for 180 days. Multivariate logistic regression was used to control for with an alpha value of 0.05 set as significant.

Results

This study identified 13,809 patients (mean age, 36.3 years) who underwent primary acetabuloplasty or femoroplasty. We also identified 10,026 patients who underwent both procedures. Postoperative complication rates were similar between the cohorts (acetabuloplasty 17.1%, femoroplasty 19.9%, P = .0622). Rates of hip fracture (femoroplasty: 2.4% vs acetabuloplasty: 2.0%, P = .0302) and heterotopic ossification (femoroplasty: 11.3% vs acetabuloplasty: 8.8%, P < .0001) were greater in the femoroplasty-only cohort. Combined acetabuloplasty and femoroplasty was associated with the greatest complication burden of 21.6% (P < .0001). After multivariate regression, differences in age, sex, comorbid status, or procedure type did not influence odds in risk for postoperative hip dislocation. Adjusted data showed that neither femoroplasty nor acetabuloplasty influenced odds of hip fracture (P > .05). Patients who were aged younger than 20 years old were significantly less likely to fracture their hips postoperatively than patients aged 60+ years (odds ratio 0.3, 95% confidence interval 0.1-0.8). Hypertension was independently associated with increased odds of hip fracture (odds ratio 1.7, 95% confidence interval 1.2-3.5).

Conclusions

Older age, male sex, and hypertension all carry increased risk for a hip fracture following acetabuloplasty or femoroplasty. Patient- and procedure-specific factors that could be assessed with this database did not influence risk for hip dislocation.

Level of Evidence

Level III; retrospective comparative observation trial.

Three-Dimensional Magnetic Resonance Arthrography of Post-Arthroscopy Hip Instability Demonstrates Increased Effective Intracapsular Volume and Anterosuperior Capsular Changes

Purpose

To quantify the magnetic resonance arthrography (MRA) capsular morphologic findings associated with postarthroscopy hip instability.

Methods

Among patients with clinically significant iatrogenic hip instability at a single center, patients with preindex and postindex surgery MRAs were identified. These MRAs were compared regarding effective intracapsular volume calculated by semi-automated 3-dimensional pixel intensity region segmentation, 2-dimensional anterior proximal intracapsular area in the femoral neck axial plane reconstruction, maximal anterior fluid pocket depth, capsule retraction distance, and capsular instability grade. Morphological measurements were conducted using Horos image processing software. Paired t-test, paired Wilcoxon signed rank test, and the McNemar test were used for identifying statistical significance.

Results

In 42 patients, mean effective intracapsular volume was significantly greater in the postindex surgery MRAs (19.44 cm³ vs 17.26 cm³; P = .006). Proximal anterosuperior (12-3 o'clock) intracapsular area was also significantly greater after index surgery (2.84 cm² vs 1.43 cm²; P < .001. Proximal anteroinferior (3-6 o'clock) intracapsular area (1.34 cm² vs 0.97 cm²; P = .002), capsule deficiency grade (P < .001), anterior capsule retraction distance (4.83 mm vs 0.34 mm; P < .001), and maximum anterior fluid depth (8.33 mm vs 4.90 mm; P <.001) were also significantly increased after index surgery.

Conclusion

In comparison to the preoperative state, iatrogenic hip instability is associated with MRA findings that include increases in total effective intracapsular volume, proximal anterosuperior and anteroinferior intracapsular cross-sectional area, maximum proximal anterosuperior fluid depth, and capsule retraction distance.

Level of Evidence

Level IV, diagnostic case series.

Capsular Repair During Hip Arthroscopy Demonstrates Restoration of Axial Distraction Resistance in an in Vivo Intraoperative Testing Model

BACKGROUND

Cadaveric models demonstrate that failure of hip capsular repair is dependent on the robustness of the repair construct. In vivo data on capsular repair construct efficacy are limited. We investigated the effect of a figure-of-8 capsular repair on hip distraction resistance relative to native and post-capsulotomy states. We hypothesized that an unrepaired capsulotomy would demonstrate increased axial distraction compared with the native state and that capsular repair would restore distraction resistance to native levels.

METHODS

Patients undergoing primary hip arthroscopy by a single surgeon were prospectively enrolled between March 2020 and June 2020. Prior to any instrumentation, fluoroscopic images of the operative hip were obtained at 12.5-lbs (5.7-kg) traction intervals, up to 100 lbs (45.4 kg). Anterolateral, modified anterior, and distal anterolateral portals were established. Following interportal capsulotomy, labral repair, and osteochondroplasty, fluoroscopic images were reobtained at each traction interval. Capsular repair was performed with use of a figure-of-8 suture configuration. Traction was reapplied and fluoroscopic images were again obtained. Joint distraction distance was measured at each traction interval for all 3 capsular states. Anteroposterior pelvic radiographs were utilized to scale fluoroscopic images to obtain joint space measurements in millimeters.

RESULTS

A total of 31 hips in 31 patients were included. Capsulotomy resulted in significant increases in distraction distance from 25 (11.3 kg) to 100 lbs of traction compared with both native and capsular repair states (all comparisons, p ≤ 0.017). Capsular repair yielded a significantly greater distraction distance compared with the native state at 37.5 lbs (17.0 kg; 5.49 versus 4.98 mm, respectively; p = 0.012) and 50 lbs (22.7 kg; 6.08 versus 5.35 mm; p < 0.001). The mean difference in distraction distance between native and capsular repair states from 25 to 100 lbs of traction was 0.01 mm.

CONCLUSIONS

This in vivo model demonstrates that an unrepaired interportal capsulotomy significantly increases axial distraction distance compared with the native, intact hip capsule. Performing a complete capsular closure reconstitutes resistance to axial distraction intraoperatively. Future research should evaluate the in vivo effects and associated clinical outcomes of other published capsular repair techniques and assess the durability of capsular repairs over time.

Biomechanical Comparison of Capsular Repair, Capsular Shift, and Capsular Plication for Hip Capsular Closure: Is a Single Repair Technique Best for All?

Background:

In hip arthroscopy, the best capsular closure technique to prevent microinstability in some patients while preventing overconstraints in other patients has yet to be determined.

Purpose:

To evaluate the biomechanical effects of capsular repair, capsular shift, and combination capsular shift and capsular plication for closure of the hip capsule.

Study Design:

Controlled laboratory study.

Methods:

Eight cadaveric hips (4 male and 4 female hips; mean age, 55.7 years) were evaluated in 7 conditions: intact, vented, capsulotomy, side-to-side repair, side-to-side repair with capsular plication (interval closure between iliofemoral and ischiofemoral ligaments), capsular shift repair, and capsular shift repair with plication. Measurements, via a 360° goniometer, included internal and external rotation with 1.5 N·m of torque at 5° of extension and 0°, 30°, 60°, and 90° of flexion. In addition, the degree of maximum extension with 5 N·m of torque and the amount of femoral distraction with 40 N and 80 N of force were obtained. Repeated-measures analysis of variance and Tukey post hoc analyses were used to analyze differences between capsular conditions.

Results:

At lower hip positions (5° of extension, 0° and 30° of flexion), there was a significant increase in external rotation and total rotation after capsulotomy versus the intact state (P < .05). At all hip flexion angles, there was a significant increase in external rotation, internal rotation, and total rotation as well as a significant increase in maximum extension after capsulotomy versus capsular shift with plication (P < .05 for all). At all flexion angles, both capsular closure with side-to-side repair (with or without plication) and capsular shift without capsular plication were able to restore rotation, with no significant differences compared with the intact capsule (P > .05). Among repair constructs, there were significant differences in range of motion between side-to-side repair and combined capsular shift with plication (P < .05).

Conclusion:

At all positions, significantly increased rotational motion was seen after capsulotomy. Capsular closure was able to restore rotation similar to an intact capsule. Combined capsular shift and plication may provide more restrained rotation for conditions of hip microinstability but may overconstrain hips without laxity.

Clinical Relevance:

More advanced closure techniques or a combination of techniques may be needed for patients with hip laxity and microinstability. At the same time, simple repair may suffice for patients without these conditions.

Anterior Hip Dislocation After Hip Arthroscopy Complicated by Iliopsoas Bursitis

Hip dislocation after hip arthroscopy is an uncommon postoperative complication. We report a case of a 51-year-old woman who underwent right hip arthroscopy and presented with an anterior hip dislocation on postoperative day five. The index surgery involved capsulotomy, cam lesion debridement, and femoroplasty for an anterosuperior labral tear and cam-type femoroacetabular impingement. The patient underwent an uneventful recovery course until eight weeks postoperatively she developed iliopsoas bursitis. Her symptoms were managed conservatively with activity modification and physical rehabilitation. Complete resolution of symptoms was reported by the six-month follow-up visit, and no further dislocations or instability had been reported at 12 months. Anterior hip dislocation is a rare complication following hip arthroscopy and patients may experience persistent iliopsoas bursitis several months following successful reduction.

Arthroscopic Triple Reconstruction in the Hip Joint: Restoration of Soft-Tissue Stabilizers in Revision Surgery for Gross Instability

Gross hip instability in an active adult with previous normal hip anatomy is usually due to disruption of the static stabilizers of the hip joint. Although such a disruption can result from a high-grade injury, it can be iatrogenic after previous hip arthroscopy. The patient may present with a painful limp and recurrent subluxation sensation in the affected hip joint. Revision hip arthroscopy in this scenario is generally complicated, and it is not uncommon for all the soft-tissue stabilizers to be compromised. The labrum, ligamentum teres (LT), and capsule of the hip joint are often so damaged that reparation is not an option. Reconstruction of the torn LT is an established method to add secondary stability while addressing the labral pathology in the hip joint with microinstability. Concomitant reconstruction of all the static restraints has yet to be described addressing triple instability. This Technical Note presents a stepwise approach, including tips and pearls, for arthroscopic triple reconstruction of the labrum, LT, and capsule. We believe this method is a safe and reproducible way to effectively treat gross hip instability in young patients.

Clinical and Radiographic Presentation of Capsular Iatrogenic Hip Instability After Previous Hip Arthroscopy

BACKGROUND

The clinical and radiographic features of iatrogenic hip instability following hip arthroscopy have been described. However, the prevalence of presenting symptoms and associated imaging findings in patients with hip instability has not been reported.

PURPOSE

To detail the prevalence of clinical and magnetic resonance arthrogram (MRA) findings in a cohort of patients with isolated hip instability and to determine midterm patient-reported outcomes in this patient population.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We retrospectively reviewed patients from 2014 to 2016 who underwent an isolated capsular repair in the revision hip arthroscopy setting. Patients were excluded if they underwent any concomitant procedures, such as labral repair, reconstruction, femoral osteoplasty, or any other related procedure. Several clinical data points were reviewed, including painful activities, mechanical symptoms, subjective instability, Beighton scores, axial distraction testing (pain, toggle, and apprehension), and distractibility under anesthesia. Patient-reported outcomes-including modified Harris Hip Score, Hip Outcome Score-Sports Subscale, Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function Computer Adaptive Test, and a return patient hip questionnaire-were collected pre- and postoperatively. Pre-revision radiographs were obtained, and lateral center-edge angle and alpha angle were measured on anteroposterior and frog-leg lateral views, respectively. Pre-revision MRAs were reviewed and evaluated for capsular changes. Capsular changes were defined as follows: 0, normal; 1, capsular redundancy; 2, focal capsular rent; and 3, gross extravasation of fluid from the capsule.

RESULTS

A total of 31 patients met inclusion criteria (5 male, 26 female; 14 right and 17 left hips). The mean age of patients was 36 years (range, 20-58 years). Overall, 27 (87%) reported hip pain with activities of daily living, and 31 (100%) experienced pain with sports or exercise. In addition, 24 (77%) had at least 1 positive finding on axial distraction testing. All patients had evidence of capsular changes on review of pre-revision MRAs. Out of 31 patients, 23 (74%) were available for follow-up at a minimum of 3.3 years and a mean ± SD of 4.6 ± 0.8 years. On average, modified Harris Hip Score improved by 20.3, Hip Outcome Score-Sports Subscale by 25.1, and PROMIS Physical Function Computer Adaptive Test by 6.4. Additionally, 20 (87%) patients reported improved or much improved physical ability, and 18 (78%) reported improved or much improved pain.

CONCLUSION

The current study suggests that patients with hip instability demonstrate high rates of pain with activities of daily living and exercise, positive findings on axial distraction testing, and evidence of capsular changes on magnetic resonance imaging. Furthermore, these patients improve with revision surgery for capsular repair at midterm follow-up.

An Anatomical Study of the Anterosuperior Capsular Attachment Site on the Acetabulum

BACKGROUND

Despite the fact that many surgeons perform partial capsular detachment from the anterosuperior aspect of the acetabulum to correct acetabular deformities during hip arthroscopy, few studies have focused on whether these detachments influence hip joint stability. The aim of this study was to investigate the capsular attachment on the anterosuperior aspect of the acetabulum. We hypothesized that the attachment on the inferior aspect of the anterior inferior iliac spine (AIIS) is wide and fibrocartilaginous and might have a substantial role in hip joint stability.

METHODS

Fifteen hips from 9 cadavers of Japanese donors were analyzed. Eleven hips were analyzed macroscopically, and the other 4 were analyzed histologically. In all specimens, the 3-dimensional morphology of the acetabulum and AIIS was examined using micro-computed tomography (micro-CT).

RESULTS

Macroscopic analysis showed that the widths of the capsular attachments varied according to the location, and the attachment width on the inferior edge of the AIIS was significantly larger than that on the anterosuperior aspect of the acetabulum. Moreover, the capsular attachment on the inferior edge of the AIIS corresponded with the impression, which was identified by micro-CT. Histological analysis revealed that the hip joint capsule on the inferior edge of the AIIS attached to the acetabulum adjacent to the proximal margin of the labrum. In addition, the hip joint capsule attached to the inferior edge of the AIIS via the fibrocartilage.

CONCLUSIONS

The capsular attachment on the inferior edge of the AIIS was characterized by an osseous impression, large attachment width, and distributed fibrocartilage.

CLINICAL RELEVANCE

It appeared that the capsular attachment on the inferior edge of the AIIS was highly adaptive to mechanical stress, on the basis of its osseous impression, attachment width, and histological features. Anatomical knowledge of the capsular attachment on the inferior edge of the AIIS provides a better understanding of the pathological condition of hip joint instability.

Should the Capsule Be Repaired or Plicated After Hip Arthroscopy for Labral Tears Associated With Femoroacetabular Impingement or Instability? A Systematic Review

PURPOSE

To critically evaluate the existing literature on hip capsule biomechanics, clinical evidence of instability, and outcomes of capsular management to answer the following question: Should the capsule be repaired or plicated after hip arthroscopy for labral tears associated with femoroacetabular impingement or instability?

METHODS

We used PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines to find articles using PubMed and Embase. Included studies were Level I through V studies and focused on hip capsule biomechanics, postarthroscopic instability, and clinical outcomes. Articles were excluded if they discussed treatment of the hip capsule during arthroplasty, dislocations without a history of arthroscopy, and pre-existing conditions. The Methodological Index for Non-randomized Studies (MINORS) was used for quality assessment of clinical outcome studies.

RESULTS

A total of 34 articles were included: 15 biomechanical studies, 9 instability case reports, and 10 outcome studies. There is consensus from biomechanical studies that the capsule is an important stabilizer of the hip and repairing it provides better stability than when unrepaired. Case reports of instability have raised concerns about capsular management during the index procedure to decrease the complications associated with this problem. Furthermore, outcome studies suggest that there may be an advantage of capsular closure versus capsulotomy during hip arthroscopy for nonarthritic patients.

CONCLUSIONS

Short-term outcome studies suggest that capsular closure is safe and effective in nonarthritic patients undergoing hip arthroscopic procedures and may yield superior outcomes compared with unrepaired capsulotomy. Moreover, biomechanical evidence strongly supports the role of capsular repair in maintaining stability of the hip. In patients with stiffness or inflammatory hip disorders, a release may be appropriate. In patients who have signs and symptoms of instability, there is existing evidence that capsular plication may be associated with significant improvement in patient-reported outcomes. Although the multiple procedures performed in combination with capsular treatment present confounding variables, current evidence appears to support routine capsular closure in most cases and to support capsular plication in cases of instability or borderline dysplasia.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

Anterior hip capsuloligamentous reconstruction with Achilles allograft following gross hip instability post-arthroscopy

The increasing use of hip arthroscopy has led to further development in our understanding of hip anatomy and potential post-operative complications. Iatrogenic gross hip instability following hip arthroscopy is a concerning complication described in recent orthopaedic literature. Post-arthroscopy hip instability is thought to be multifactorial, related to a variety of patient, surgical and post-operative factors. Given its infrequency, there is scarcity of literature describing appropriate surgical management and operative technique for addressing this instability. This study reports a case of gross hip instability following hip arthroscopy, describing a novel technique of management through anterior hip capsuloligamentous reconstruction with Achilles tendon allograft. Level of evidence V, Case Study.

Gross Instability After Hip Arthroscopy: An Analysis of Case Reports Evaluating Surgical and Patient Factors

PURPOSE

Gross hip instability is a rare complication after hip arthroscopy, and there is limited literature surrounding this topic. This systematic review investigates cases of gross hip instability after arthroscopy and discusses the risk factors associated with this complication.

METHODS

A systematic search was performed in duplicate for studies investigating gross hip instability after hip arthroscopy up to October 2015. Study parameters including sample size, mechanism and type of dislocation, surgical procedure details, patient characteristics, postoperative rehabilitation protocol, and level of evidence were analyzed.

RESULTS

The systematic review identified 9 case reports investigating gross hip instability after hip arthroscopy (10 patients). Anterior dislocation occurred in 66.7% of patients, and most injuries occurred with a low-energy mechanism. Common surgical factors cited included unrepaired capsulotomy (77.8%) and iliopsoas release (33.3%), whereas patient factors included female gender (77.8%), acetabular dysplasia (22.2%), and general ligamentous laxity (11.1%). Postoperative restrictions and protocols were variable and inconsistently reported, and their relation to post-arthroscopy instability was difficult to ascertain.

CONCLUSIONS

This systematic review discussed various patient, surgical, and postoperative risk factors of gross hip instability after arthroscopy. Patient characteristics such as female gender, hip dysplasia, and ligamentous laxity may be risk factors for post-arthroscopy dislocation. Similarly, surgical risk factors for iatrogenic hip instability may include unrepaired capsulotomies and iliopsoas debridement, although the role of capsular closure in iatrogenic instability is not clear. The influences of postoperative restrictions and protocols on dislocation are also unclear in the current literature. Surgeons should be cognizant of these risk factors when performing hip arthroscopy and be mindful that these factors appear to occur in combination.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Editorial Commentary: Iatrogenic Instability of the Hip: A Perfect Storm

Iatrogenic instability of the hip is likely a perfect storm with enough factors coming together just wrong to create the problem. Capsular neglect is but one potential component. Instability is also just one of a myriad of problems that can be encountered following hip arthroscopy that ranges on a spectrum from too loose to too stiff with numerous reasons in between for incomplete pain relief and residual dysfunction. Proper capsular management does not always mean capsular repair.