Ehlers-Danlos Syndrome: Arthroscopic Management for Extreme Soft-Tissue Hip Instability

Total hip arthroplasty outcomes in Ehlers-Danlos patients: data from the Statewide Planning and Research Cooperative System

INTRODUCTION

Ehlers-Danlos syndromes (EDS) are genetic connective tissue disorders affecting multiple organ systems that frequently result in connective tissue hyperlaxity and early osteoarthritis. Short- and long-term outcomes after primary total hip arthroplasty (THA) in this patient population remain poorly characterised. The primary purpose of this study is to compare postoperative outcomes and survivorship after primary THA in patients with and without EDS.

METHODS

The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried for all patients undergoing primary elective THA between September 2009 and December 2020. Patients with EDS were identified using ICD9 and ICD10 diagnosis codes. Given the relatively low incidence of EDS in this patient population, the cohort was propensity-matched 1:10 to patients without diagnosis of EDS based on demographics characteristics and medical comorbidities as measured by the Elixhauser Comorbidity Index.

RESULTS

A total of 66 THA patients with and 660 without EDS were included in each group after 1:10 propensity-matching. There were no significant differences in baseline characteristics or THA indications. Early postoperative outcomes such as length of hospital stay and discharge disposition were similar. Emergency Room visits and inpatient readmission rates at 3 months postoperatively did not significantly differ between groups. Patients with EDS had a higher overall revision rate compared to those without (15.0% vs. 3.2%, p < 0.001). Revision free survival after primary THA in patients with EDS was significantly lower than those without EDS at 9-year follow-up. Cox proportional hazard regression demonstrated EDS patients had 7-times higher risk of revision (hazard ratio [HR] 7.43; 95% CI, 3.46-16.00; p < 0.001). Lastly, revision due to instability insignificantly trended higher in the EDS cohort (HR 2.29; 95% CI, 0.95-5.49; p = 0.063).

CONCLUSIONS

EDS patients undergoing primary THA have increased rate of all cause revision and demonstrate decreased revision free survival compared to non-EDS THA patients.

10-Year Cumulative Incidence and Indications for Revision Total Joint Arthroplasty for Patients Who Have Ehlers-Danlos syndrome

BACKGROUND

Long-term complications following total joint arthroplasty are not well established for patients who have Ehlers-Danlos syndrome (EDS), a group of connective tissue disorders. This study compared 10-year incidence of revision surgery after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in patients who have and do not have EDS.

METHODS

A retrospective cohort analysis was conducted using a national all-payer claims database from 2010 to 2021 to identify patients who underwent primary TKA or THA. Patients who had and did not have EDS were propensity-score matched by age, sex, and a comorbidity index. Kaplan-Meier analyses and Cox proportional hazard models were utilized to determine the cumulative incidence and risks of revision experienced by patients who have and do not have EDS.

RESULTS

The EDS patients who underwent TKA had a higher risk of all-cause revision (hazard ratio (HR): 1.50, 95% confidence interval (95% CI): 1.09 to 2.07, P < 0.014) and risk of revision due to instability (HR = 2.49, 95% CI: 1.37 to 4.52, P < 0.003). The EDS patients who underwent THA had a higher risk of all-cause revision (HR = 2.32, 95% CI: 1.47 to 3.65, P < 0.001), revision due to instability (HR = 4.26, 95% CI: 2.17 to 8.36, P < 0.001), and mechanical loosening (HR = 3.63, 95% CI: 2.05 to 6.44, P < 0.001).

CONCLUSION

Patients who had EDS were found to have a higher incidence of revision within 10 years of undergoing TKA and THA compared to matched controls, especially for instability. Patients who have EDS should be counseled accordingly. Surgical technique and implant selection should include consideration for increased constraint in TKA and larger femoral heads or dual mobility articulations for THA.

Capsular Repair Versus No Repair After Hip Arthroscopy in Patients Without Dysplasia or Generalized Ligamentous Laxity: A Systematic Review and Meta-analysis

Background

Many recent studies have shown that patients who undergo capsular repair after hip arthroscopy achieve superior clinical outcomes compared with those who do not. However, patients with dysplasia or generalized ligamentous laxity (GLL) were not excluded from most of these studies, which may have affected the outcomes.

Purpose

To determine whether capsular repair influences the outcomes of hip arthroscopy for patients without dysplasia or GLL.

Study Design

Systematic review; Level of evidence, 1.

Methods

Under the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, randomized controlled trials comparing the outcomes of capsulotomy with versus without repair were included, but studies that included patients with dysplasia or GLL were excluded. The study outcomes were patient-reported outcome measures (PROMs) at 6 months and 2 years postoperatively-including the modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), and Hip Outcome Score-Sport-Specific Subscale (HOS-SSS)- and were compared between the repair and no-repair groups. A narrative analysis and meta-analysis were performed to integrate and compare the results of the 2 groups. In the meta-analysis of the outcome measures, studies with significant differences in the preoperative scores between the repair and no-repair groups were excluded because previous studies have shown that these can affect the outcomes.

Results

A total of 761 studies were initially identified, of which 3 were included. Of the 322 included patients, 136 underwent capsular repair, and 186 underwent capsulotomy with no repair. The meta-analysis showed that capsular repair was associated with significantly higher postoperative PROMs: the mHHS at 2 years (P = .03), the HOS-ADL at 6 months (P = .02) and 2 years (P < .0001), and the HOS-SSS at 6 months (P = .02) and 2 years (P = .001).

Conclusion

Capsular repair after hip arthroscopy was associated with superior clinical outcomes when compared with no capsular repair in patients without dysplasia or GLL.

Increased Opioid Use in Patients With Ehlers-Danlos Syndrome Before and After Total Hip Arthroplasty

Background

Ehlers-Danlos syndrome (EDS), a disorder affecting synthesis of collagen, typically presents with chronic pain, hypermobility, and early osteoarthritis. EDS patients undergoing total hip arthroplasty (THA) are at risk of dislocation and revision. Opioid use and impact on outcomes among this population remain unknown.

Methods

A retrospective review was performed with a large national database querying the International Classification of Disease, tenth revision procedure codes identifying 1,244,368 primary THAs from 2015-2020. Two hundred thirty-eight EDS patients underwent THA and were propensity matched with population control based on age, sex, and obesity when comparing opioid prescription. To compare dislocation and revision outcomes, EDS patients were stratified into those receiving opioid prescriptions and those not. Multivariate analysis evaluated the association.

Results

EDS patients were more likely prescribed opioids 90 days before (49.1% vs 34.7.0%, P < .0001) and after THA (59.7% vs 41.2%, P < .0001), with more preoperatively (1163.6 mme ±1562.8, P < .0001) and postoperatively (900.1 mme ±1235.9, P < .0001) than controls. In EDS patients prescribed opioids 90 days before THA, dislocation rate was 12.8% vs 7.1% not prescribed (odds ratio 2.08, 95% confidence interval 0.85-5.1). 14.8% of EDS patients who received opioids 90 days after THA dislocated vs 2.1% not prescribed (odds ratio 8.13, 95% confidence interval 1.87-35.7).

Conclusions

EDS patients are more likely prescribed opioids before and after THA. Opioid prescription was associated with risk of dislocation, though we caution interpretation of causation. However, this suggests that the risks of worse outcomes in EDS patients undergoing THA are multifactorial. We should look at strategies to reduce opioid use prior to THA.

Hip Arthroscopy in Patients With Generalized Joint Hypermobility Yields Successful Outcomes: A Systematic Review

PURPOSE

To evaluate the outcomes of hip arthroscopy in patients with generalized joint hypermobility (GJH).

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. An electronic record search was performed in PubMed, Web of Science, Cochrane Library, and Embase. A 2-stage title/abstract and full-text screening was performed using the following inclusion criteria: (1) observational studies, cohort studies, and randomized controlled trials; (2) describing more than 5 patients with a mean age over 18 years and GJH; (3) undergoing arthroscopy of the hip; (4) reporting patient-reported outcome measures (PROMs), return to sport, or complications/reoperations; and (5) published in English.

RESULTS

Of the 517 articles identified, 10 studies meeting all selection criteria were included. Included studies report significant improvements in a range of different functional and pain-based PROMs. Most patients (25.0%-97.0%) in each study achieved a clinically important improvement postoperatively in at least 1 PROM. No complications were described in any of the 4 studies reporting this metric. One study each found an association between GJH and an increased risk of postoperative deep gluteal syndrome and iliopsoas tendinitis. The rate of revision arthroscopy ranged from 0% to 11.4%, and only 2 patients in a single study of 11 hips required conversion to total hip arthroplasty. No statistically significant differences were reported between patients with and without GJH with respect to any of the described outcomes.

CONCLUSIONS

Patients with GJH may achieve good outcomes following hip arthroscopy with respect to PROMs, perioperative complications, reoperation, and return to sport. With effective labral repair and capsular closure, outcomes achieved in patients with GJH are comparable to those reported in patients without hypermobility.

LEVEL OF EVIDENCE

Level IV, systematic review of level III to IV studies.

Hip Pain and Movement Dysfunction Associated With Nonarthritic Hip Joint Pain: A Revision

The Academy of Orthopaedic Physical Therapy (AOPT), formerly the Orthopaedic Section of the American Physical Therapy Association (APTA), has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). This is an update to the 2014 Clinical Practice Guideline (CPG) for Hip Pain and Movement Dysfunction Associated with Nonarthritic Hip Joint Pain. The goals of the revision were to provide a concise summary of the contemporary evidence since publication of the original guideline and to develop new recommendations or revise previously published recommendations to support evidence-based practice. This current CPG covers pathoanatomical features, clinical course, prognosis, diagnosis, examination, and physical therapy interventions in the management of nonarthritic hip joint pain. J Orthop Sports Phys Ther 2023;53(7):CPG1-CPG70. doi:10.2519/jospt.2023.0302.

Treatment of Hip Microinstability with Arthroscopic Capsular Plication: A Retrospective Case Series

Purpose

Hip microinstability is defined as hip pain with a snapping and/or blocking sensation accompanied by fine anatomical anomalies. Arthroscopic capsular plication has been proposed as a treatment modality for patients without major anatomic anomalies and after failure of properly administered conservative treatment. The purpose of this study was to determine the efficacy of this procedure and to evaluate potential predictors of poor outcome.

Materials and Methods

A review of 26 capsular plications in 25 patients was conducted. The mean postoperative follow-up period for the remaining patients was 29 months. Analysis of data included demographic, radiological, and interventional data. Calculation of pre- and postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis) index was performed. Pre- and postoperative sports activities and satisfaction were also documented. A P<0.05 was considered significant.

Results

No major complications were identified in this series. The mean pre- and postoperative WOMAC scores were 62.6 and 24.2, respectively. The WOMAC index showed statistically significant postoperative improvement (P=0.0009). The mean satisfaction rate was 7.7/10. Four patients with persistent pain underwent a periacetabular osteotomy. A lateral center edge angle ≤21° was detected in all hips at presentation. We were not able to demonstrate any difference in postoperative evolution with regard to the presence of hip dysplasia (P>0.05), probably because the sample size was too small.

Conclusion

Capsular plication can result in significant clinical and functional improvement in carefully selected cases of hip microinstability.

Hip microinstability diagnosis and management: a systematic review

PURPOSE

The purpose of this systematic review is to present the most common causes, diagnostic features, treatment options and outcomes of patients with hip micro-instability.

METHODS

Three online databases (MEDLINE, Embase, and PubMed) were searched from database inception March 2022, for literature addressing the diagnosis and management of patients with hip micro-instability. Given the lack of consistent reporting of patient outcomes across studies, the results are presented in a descriptive summary fashion.

RESULTS

Overall, there were a total of 9 studies including 189 patients (193 hips) included in this review of which 89% were female. All studies were level IV evidence with a mean MINORS score of 12 (range: 10-13). The most commonly used features for diagnosis of micro-instability on history were anterior pain in 146 (78%) patients and a subjective feeling of instability with gait in 143 (81%) patients, while the most common feature on physical examination was the presence of anterior apprehension with combined hip extension and external rotation in 123 (65%) patients. The most common causes of micro-instability were iatrogenic instability secondary to either capsular insufficiency or cam over-resection in 76 (62%) patients and soft tissue laxity in 38 (31%) patients.

CONCLUSION

The most common symptom of micro-instability on history was anterior hip pain and on physical exam was pain with hip extension and external rotation. There are many treatment options and when managed appropriately based on the precise cause of micro-instability, patients may demonstrate improved outcomes.

LEVEL OF EVIDENCE

IV.

What is the utility of hip arthroscopy in patients with joint laxity? A contemporary systematic review of patient-reported and surgical outcomes

INTRODUCTION

The purpose of this study was to systematically review the literature to understand the contemporary outcomes for patients with joint laxity managed with hip arthroscopy.

MATERIALS AND METHODS

A search was performed utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement guidelines. All literature related to joint laxity in hip arthroscopy patients was identified. Inclusion criteria consisted of patient-reported outcomes and Beighton and Horan Joint Mobility Index scoring. Study quality was assessed using the Methodological Index of Non-Randomized Studies criteria.

RESULTS

Seven articles were identified, including 412 patients (416 hips). Patients were predominantly female (range 83-100%). Mean patient age ranged from 13-69 years. Five studies consisting of 370 hips reported a range of 75 to 100% undergoing labral repair, 0 to 13% labral debridement, 0 to 7% labral reconstruction, 43 to 100% capsular closure, 94 to 99% femoroplasty, 3 to 80% rim resection, and 9 to 50% subspine decompression for surgical management. Post-operative follow-up range was 6-99 months. The mean range of improvement in Hip Outcomes Score Activities of Daily Living, Hip Outcomes Score-Sports Subscale, modified Harris Hip Score, Visual Analog Scale, and 12 item Short Form Health Survey were 17.6-31.3, 31.3-35.1, 22.5-53.8, - 2.79-8, and 12.4-16.9 respectively.

CONCLUSION

Generalized ligamentous laxity patients managed with hip arthroscopy were predominantly young women. At short-term follow-up, mean patient-reported outcomes were positive, with improvement postoperatively in activities of daily living, sports, and quality of life.

Effective Management Options for Treatment of Microinstability of the Hip: a Scoping Review

PURPOSE OF REVIEW

To review the recent literature identifying and summarizing the research involving management of microinstability of the hip and highlight new and evolving techniques in its treatment.

RECENT FINDINGS

Recent updates in the understanding of capsular management hip arthroscopy will likely lead to less revision surgery and a decreased incidence of persistent post-operative pain. Repair of residual capsular defects has shown good outcomes with high patient satisfaction. Capsular plication remains the gold standard for hips with increased pain that show signs of capsular laxity/deficiency on exam or imaging. Capsular reconstruction has shown equivalent results to other revision hip arthroscopy procedures with low rates of complications. Ligamentum teres pathology, although rare, should be considered a source of pain, particularly in patients with laxity on exam. In cases where CAM over-resection has occurred, remplissage using allograft is an effective option for restoring the capsular suction seal and stability. Microinstability is increasingly being recognized as a source of post-operative hip pain. Patients with collagen disorders remain a challenging clinical entity with increased rates of complications and post-operative pain. CAM resection should be performed carefully and not disrupt the suction seal but be sufficient to not cause further impingement. Improved evidence including well-designed prospective studies with large sample sizes will determine the future management of this complex problem.

Editorial Commentary: Restoration of Hip Capsular Tension Is More Important Than Repair Construct Configuration

The debate regarding optimal capsular management during hip arthroscopy has been evolving for over 20 years. Femoroacetabular impingement emerged in the arthroscopic world in the early 2000s. However, the ability to address osseous deformities and decompress and/or reshape them was limited by the hip capsular structures and small capsulotomies. Some surgeons attempted to arthroscopically manage these deformities with limited capsulotomies, with not surprisingly limited success. Others made larger capsular windows (capsulectomies) to more accurately manage these deformities but potentially left some patients with varying degrees of iatrogenic microinstability or macroinstability. Over time, an increasing awareness of post-arthroscopy instability in the form of case reports, case series, and backroom chatter among the hip arthroscopy thought leaders brought the idea of routine capsular closure to the forefront. Biomechanical studies defined the role of the hip capsular ligaments, the deficits created with various capsulotomies during surgery, and the ability to restore stability after capsular repair. Clinical studies revealed better outcomes and lower revision rates after capsular repair for subtle osseous and soft-tissue instability, revision cases, and athletes compared with unrepaired capsulotomies. Various capsular repair constructs (side-to-side repairs, capsular shifts, and various suture configurations and suture materials) have been proposed, without evidence to support a superior technique or suture material. In the end, capsular management is an evolving art that takes into account various patient-specific factors (i.e., individual activity requirements, soft-tissue and osseous parameters, and intraoperative impressions) with the end goal of achieving a stable, impingement-free joint. There might be various capsular management roads to travel, but the destination remains the same.

Improvement in pain and patient-related outcome measures following hip arthroscopy in patients with femoroacetabular impingement syndrome and concomitant generalized ligamentous laxity: a systematic review

PURPOSE

Within orthopaedic sports medicine, concomitant ligamentous laxity is often found to be a negative prognostic factor for post-operative outcomes following various procedures. The effect of ligamentous laxity on outcomes following hip arthroscopy remains infrequently reported. Therefore, the purpose of this study is to report on the outcomes of hip arthroscopy for the treatment of femoroacetabular impingement syndrome (FAIS) with concomitant generalized ligamentous laxity (GLL).

METHODS

A systematic search was performed in Medline, EMBASE, CENTRAL, and SPORTDiscus (from inception to April 2021) for studies reporting outcomes following hip arthroscopy for symptomatic FAIS in patients with concomitant GLL.

RESULTS

Six studies representing 213 patients and 231 hips were included. Outcomes of pain and functional scores as measured by VAS, Harris Hip Score, and Hip Disability and Osteoarthritis Outcomes Score were tabulated. A mean improvement of 4.8 on VAS was observed. Improvements of 30.0 on HHS, 33.1 for ssHOS, and 23.9 for ADL-HOS were observed.

CONCLUSION

Hip arthroscopy is an effective method of alleviating pain and improving function with statistically significant improvements in all PROM in patients with concomitant FAIS with GLL.

LEVEL OF EVIDENCE

IV.

PROSPERO REGISTRATION

CRD42021248864.

Editorial Commentary: Hip Joint Laxity, Microinstability, or Instability Require Precise Definition: No Matter What You Call It, It's Here to Stay!

Hip instability has gained recognition as an important cause of hip pathology. Causes include incongruency of the articular surfaces due to dysplasia and/or impingement, joint capsule pathology, labral pathology, ligamentum teres tears, ligamentous laxity, muscular imbalance, and tendon tears. Lacking clearly defined symptoms and tests has hindered identification and treatment of this condition. Furthermore, the relevant literature uses different terms such as hyperlaxity and microinstability to describe this patient population, conveying different messages. However, the different terms convey different messages. Joint hyperlaxity or hypermobility has sometimes been used in reference to the hip; however, these usually refer to a genetic ligamentous and capsular condition affecting collagen structure, such as in Ehlers Danlos Syndrome. More common, and often interchangeable, terms are instability and microinstability. As the authors state in the present study, 'instability' has the advantage of conveying the significant impact the condition has on a patient's life. On the other hand, 'microinstability' may more accurately reflect the vague clinical presentation that we often encounter in the average hip patient with instability. Most patients do not complain of symptoms commonly seen in other joints with "instability," such as giving way, subluxation, and recurrent dislocations. In the hip, the symptoms are generally less tangible, and hence, the term "microinstability" may be more appropriate.

A New Parameter of Hip Instability in Developmental Dysplasia of the Hip (DDH): Teardrop Distance

Background

Hip instability is one of the etiologies of accelerated onset of osteoarthritis in developmental dysplasia of the hip (DDH). There are some radiological parameters for hip instability in hip dysplasia like broken shenton’s line, elevated acetabular index, reduced lateral center edge angle (LCEA), upsloping lateral sourcil. We have discovered a new index of teardrop distance (TD) for assessing instability. Herein, we hypothesized that increased TD could be used as evidence of hip instability in DDH patients, which we verified using TD as an auxiliary diagnostic parameter for DDH, from supine to standing position.

Methods

Female DDH patients undergoing Bernese periacetabular osteotomy (PAO) were enrolled in the DDH group, and normal female volunteers were in the control group. Anteroposterior radiographs of the pelvis in the supine and standing positions were taken, and LCEA, Tönnis angle (TA), sharp angle (SA), and TD were tested using Stata software to analyze the changes between supine and standing anteroposterior pelvic radiographs.

Results

There were 26 female volunteers with 52 hips in the control group: supine TD 6.80 ± 0.98 mm, standing TD 6.65 ± 1.3 mm (P > 0.05). A total of 78 patients with 135 hips were included in the DDH group: supine TD 10.51 ± 3.50 mm, standing TD 10.93 ± 4.23 mm (P < 0.05). In either supine or standing position, TD in the DDH group was significantly wider than that in the control group (P < 0.05). In the DDH group, TD was correlated with TA and LCEA (rp 0.494–0.588, P < 0.05); TD was not correlated with SA, weight, or BMI (P > 0.05). There was a weak correlation between TD difference and standing LCEA (rp −0.276, P < 0.05).

Conclusion

TD > 10 mm was a common imaging feature of DDH. It increased from supine to standing position, thus indicating hip instability in DDH patients. The hip parameters of both positions should be compared, fully considering the factors of hip stability.

Routine Capsular Closure With Hip Arthroscopic Surgery Results in Superior Outcomes: A Systematic Review and Meta-analysis

BACKGROUND

In hip arthroscopic surgery, capsulotomy is performed to improve visualization and allow instrumentation of the joint. Traditionally, the defect has been left unrepaired; however, increasing evidence suggests that this may contribute to persistent pain and iatrogenic capsular instability. Nevertheless, the clinical benefit of performing routine capsular repair remains controversial.

PURPOSE/HYPOTHESIS

We conducted a systematic review and meta-analysis to investigate the effects of routine capsular closure on patient-reported outcomes (PROs), hypothesizing that superior PROs would be observed with routine capsular closure.

STUDY DESIGN

Meta-analysis and systematic review; Level of evidence, 4.

METHODS

A systematic review and meta-analysis was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The terms "hip,""arthroscopy,""capsule,""capsular,""repair," and "closure" were used to query Ovid MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), CINAHL (Cumulative Index to Nursing and Allied Health Literature), SPORTDiscus, and PubMed. Articles with PROs stratified by capsular management were included. Multivariate mixed-effects metaregression models were implemented with study-level random-effects and fixed-effects moderators for capsular closure versus no repair and after controlling for surgical indication and preoperative PROs. The effect of repair on both the postoperative score and the change in scores was evaluated via the Harris Hip Score (HHS)/modified HHS (mHHS), Hip Outcome Score (HOS)-Activities of Daily Living (ADL), and HOS-Sport Specific Subscale (SSS), with a supplemental analysis of additional outcomes.

RESULTS

Of 432 initial articles, 36 were eligible for analysis, with results for 5132 hip arthroscopic procedures. The capsule was repaired in 3427 arthroscopic procedures and unrepaired in 1705. Capsular repair was associated with significantly higher postoperative HHS/mHHS (2.011; SE, 0.743 [95% CI, 0.554-3.467]; P = .007), HOS-ADL (3.635; SE, 0.873 [95% CI, 1.923-5.346]; P < .001), and HOS-SSS (4.137; SE, 1.205 [95% CI, 1.775-6.499]; P < .001) scores as well as significantly superior improvement on the HHS/mHHS (2.571; SE, 0.878 [95% CI, 0.849-4.292]; P = .003), HOS-ADL (3.315; SE, 1.131 [95% CI, 1.099-5.531]; P = .003), and HOS-SSS (3.605; SE, 1.689 [95% CI, 0.295-6.915]; P = .033).

CONCLUSION

This meta-analysis is the largest to date evaluating the effect of capsular closure on PROs and demonstrates significantly higher mean postoperative scores and significantly superior improvement with repair, while controlling for the effects of preoperative score and surgical indication. The true magnitude of the benefit of capsular repair may be clarified by large prospective randomized studies using PRO measures specifically targeted and validated for hip arthroscopic surgery/preservation.

Fluoride increases the susceptibility of developmental dysplasia of the hip via increasing capsular laxity triggered by cell apoptosis and oxidative stress in vivo and in vitro

The etiology of developmental dysplasia of the hip (DDH) is multifactorial, including breech presentation and hip capsular laxity. In particular, hip laxity is the main contributor to DDH by changing the ratio and distribution of collagens. Also, fluoride (F) affects collagens from various tissue besides bone and tooth. To investigate the association of DDH and excessive F intake, we conducted this research in lab on cell and animal model simultaneously. We established animal model of combination of DDH and F toxicity. The incidence of DDH in each group was calculated, and hip capsules were collected for testing histopathological and ultrastructural changes. The primary fibroblasts were further extracted from hip capsule and treated with F. The expression of collagen type I and III was both examined in vivo and in vitro, and the level of oxidative stress and apoptosis was also tested identically. We revealed that the incidence of DDH increased with F concentration. Furthermore, the oxidative stress and apoptosis levels of hip capsules and fibroblasts both increased after F exposure. Therefore, this study shows that excessive F intake increases susceptibility to DDH by altering hip capsular laxity in vivo and in vitro respectively. We believe that F might be a risk factor for DDH by increasing hip laxity induced by triggering fibroblast oxidative stress and apoptosis.

Protocol for a multicenter prospective cohort study evaluating arthroscopic and non-surgical treatment for microinstability of the hip joint

BACKGROUND

Microinstability of the hip joint is a proposed cause of hip pain and reduced function in young individuals. The underlying mechanism is thought to be extraphysiological hip motion due to bony deficiency and/or soft tissue deficiency or decreased soft tissue function. Recently, the condition has gained increased attention, and despite the fact that treatment today includes both non-surgical and surgical approaches, there is limited evidence on diagnostic specificity and treatment effects. The aim of this study is to evaluate clinical outcomes of both non-surgical and surgical treatment for microinstability of the hip joint.

METHODS

A multicenter prospective cohort study is planned to evaluating the outcome of physical therapy aimed at stabilizing the hip joint, as well as arthroscopic plication of the hip joint capsule, if the physical therapy fails. Outcomes will be evaluated using hip-specific patient-reported outcome measures: the short version of the International Hip Outcome Tool and the Copenhagen Hip and Groin Outcome Score, strength and function tests, health-related quality of life as determined using the European Quality of Life-5 Dimensions and the European Quality of Life-Visual Analog Scale, sports activity levels according to the Hip Sport Activity Scale, and reported complications. Patients will be evaluated at 6, 12 and 24 months after each treatment.

DISCUSSION

It is important to evaluate the clinical outcomes of both non-surgical and surgical treatment for suspected microinstability of the hip joint, and the planned prospective evaluation will contribute to the understanding of non-surgical as well as surgical treatment outcomes, including complications.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04934462 . Registered June 22 2021.

Patients With Ehlers-Danlos Syndromes Experience Higher Rates of Prosthetic Dislocation After Total Hip Arthroplasty and Worse Implant Survival at 5 Years

INTRODUCTION

Ehlers-Danlos syndromes (EDS) are genetic connective tissue disorders affecting multiple organ systems that frequently result in connective tissue hyperlaxity and early osteoarthritis. Short- and long-term outcomes after total hip arthroplasty in this cohort remain poorly characterized.

METHODS

Data were abstracted from the 2010 to 2018 PearlDiver Mariner administrative database. Patients with EDS undergoing total hip arthroplasty for osteoarthritis were identified and matched 1:10 to patients without a diagnosis of EDS. Ninety-day incidence of postoperative complications and hospital readmission were identified and compared. Odds of 90-day adverse events were compared using multivariate logistic regression. Finally, 5-year implant survival was compared using a log-rank test. Significance was set at P < 0.005 after Bonferroni correction.

RESULTS

Matching was done for 354 patients with EDS to 3,518 patients without EDS. Patients with EDS had markedly higher rates of periprosthetic dislocation within 90 days of surgery (4.2% dislocation rate in EDS vs. 1.7% in matched control subjects, P = 0.001). On multivariate analysis, patients with EDS continued to have increased odds of dislocation in the 90-day postoperative period (Odds Ratio=2.64, P = 0.001), whereas the rates of the other studied adverse events were not markedly different between groups. At 5 years, 92.7% of patients with EDS and 96.1% of the matched control subjects remained unrevised (significant log rank difference, P = 0.004).

CONCLUSION

Compared with patients without EDS, patients with EDS were found to have a higher rate of perioperative dislocation and markedly lower implant survival at 5 years. These findings are consistent with the increased connective tissue laxity associated with EDS.

Hip Capsular Deficiency-A Cause of Post-Surgical Instability in the Revision Setting Following Hip Arthroscopy for Femoroacetabular Impingement

PURPOSE OF REVIEW

To characterize current concepts in capsular repair and hip instability, and examine findings from biomechanical and clinical studies on hip capsular management strategies as they pertain to hip stability, patient outcomes, and hip arthroscopy failure. Further, we discuss the clinical evaluation and treatment of capsular deficiency.

RECENT FINDINGS

There remains debate regarding the optimal capsular management strategies in hip arthroscopy, particularly concerning the necessity of routine capsular repair. A variety of capsulotomy techniques exist and may be used to access the hip joint. Additionally, a wide variety of techniques are employed to repair the hip capsule. Biomechanical evidence supports capsular closure restores hip joint stability to that of the intact, native state. Several clinical studies in both primary and revision hip arthroscopy settings have demonstrated improved pain and functional outcomes in patients who underwent capsular repair or capsular reconstruction. Studies have shown capsular repair may be especially important in patients with ligamentous laxity and hip dysplasia, and in competitive athletes. Post-surgical hip instability secondary to capsular insufficiency is increasingly recognized as a cause of hip arthroscopy failure. Capsular closure restores native biomechanical stability to the hip joint, and several clinical studies report improved pain and functional outcomes following capsular repair or capsular reconstruction in both the primary and revision hip arthroscopy settings. There remains much to learn regarding capsular hip instability as it relates to optimal capsular management surgical technique, intra-operative capsular management decision-making, clinical diagnosis, and related advanced imaging findings.

Interrater Reliability of the Prone Apprehension Relocation Test

Background:

The Prone Apprehension Relocation Test (PART) augments existing radiographic measures and clinical provocative maneuvers in diagnosing hip instability. One measure of the potential clinical utility of the PART depends on the reproducibility of test results by evaluating providers including physicians, licensed athletic trainers, and physical therapists.

Purpose:

To determine the interrater reliability of the PART among health care providers.

Study Design:

Cohort study (diagnosis); Level of evidence, 3.

Methods:

We retrospectively identified patients in our institution’s hip preservation registry who presented between September 2017 and June 2019 for evaluation of hip pain. Patients included in the study had the PART performed by a single physician as well as 1 of 12 physician extenders (a licensed athletic trainer or a physical therapist). The providers were blinded to the findings of the other examining professional. Interrater reliability was assessed using the Cohen κ (≥0.75 was considered excellent; between 0.75 and 0.40, moderate; and ≤0.40, poor).

Results:

A total of 96 patients (190 hips) were included in this study (61 women and 35 men, average age 32 ± 12.1 years). A total of 23 hips had a positive PART from both examiners. Interrater reliability was excellent between health care professionals for the PART when evaluating the right hip (κ = 0.80), left hip (κ = 0.82), and when combining the results for left and right (κ = 0.81). A subanalysis of patients with a positive PART from both raters demonstrated that 19 of the 23 hips had a lateral center-edge angle >25°.

Conclusion:

Our study demonstrated excellent interrater reliability of the PART, supporting its use in the physical evaluation of painful hips.

Capsular Repair May Improve Outcomes in Patients Undergoing Hip Arthroscopy for Femoroacetabular Impingement: A Systematic Review of Comparative Outcome Studies

PURPOSE

To review the existing literature in order to determine the effect of hip capsule repair on outcomes after hip arthroscopy for femoroacetabular impingement syndrome.

METHODS

This study used Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to find articles by using PubMed and Embase. Included studies were Level I through III studies that focused on patient outcomes as a function of hip capsular treatments: capsulotomy repair, partial repair, plication, and unrepaired capsulotomies. The Methodological Index for Non-randomized Studies was used for quality assessment of clinical outcome studies. After applying inclusion and exclusion criteria, a total of 16 comparative outcome studies evaluating 2,996 hips were included; they evaluated the following capsular management techniques: complete repair (n = 1,112, 37.1%), partial repair (n = 32, 1.1%), plication (n = 223, 7.4%), and unrepaired capsulotomy (n = 1629, 54.4%).

RESULTS

Of the 16 studies, 13 included patient-reported outcome scores (PROs), 3 included imaging outcomes data, and 2 reported on reoperation. Of the studies, 10 directly compared patient-reported outcomes between a capsular repair group and an unrepaired group. Of the 10 studies that directly compared PROs between a group with unrepaired capsulotomy and a group with capsular repair, 8 studies demonstrated statistically significantly better PROs in the repaired group compared to the unrepaired group, and 2 studies found no difference between the groups. Reoperation rates demonstrated mixed results between groups, and no difference was found in regard to imaging outcomes.

CONCLUSIONS

Midterm outcome studies suggest that capsular repair is safe and effective in patients without arthritis who are undergoing hip arthroscopy, and it may result in superior PROs compared with those found after unrepaired capsulotomy. Studies consistently demonstrate similar or superior outcomes in cohorts after capsular repair compared to unrepaired capsulotomy, and no studies reported superior results in unrepaired capsulotomy patients.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through Level III studies.

Editorial Commentary: Psoas Tenotomy in the Setting of a Borderline Dysplastic Hip Risks Iatrogenic Instability: Be Extremely Cautious and Particularly in Athletes

Successful outcomes after psoas tenotomies have been reported and proposed in the setting of recalcitrant internal snapping and psoas impingement. However, case reports citing hip flexion weakness and iatrogenic instability created concern regarding the role for psoas tenotomies. Despite these concerns, some recent studies reporting improved outcomes after endoscopic psoas tenotomies breathe further life into this controversial topic. Psoas tenotomy in the setting of a borderline dysplastic hip likely carries an even greater risk for iatrogenic instability. It might be critical to evaluate for clinical signs and symptoms of instability in addition to radiographic parameters to avoid this potentially devastating complication. In addition, the traditional definition of borderline dysplasia is based on lateral acetabular coverage that might be less important than anterior acetabular coverage and femoral version when contemplating psoas tenotomies on the basis of the dynamic anterior stabilizing effect of the iliopsoas myotendinous unit. Surgeons should also be extremely cautious when considering psoas tenotomy in an athletic population with the potential for persistent weakness and limited data hinting at inferior sports specific outcomes. In the end, it is not clear whether the psoas tenotomy "drives" the improvements seen in some studies, or whether many of these patients ultimately battle their way into a minimally clinically important difference "despite" the psoas tenotomy.

Capsular Management Techniques and Hip Arthroscopy

There has been an increased emphasis on capsular management during hip arthroscopy in the literature in recent years. The capsule plays a significant role in the hip joint stability and studies have demonstrated that capsular closure can restore the biomechanics of the hip back to the native state. Capsular management also affects functional outcomes with capsular repair resulting in better clinical outcomes in some studies. Management of the capsule has evolved in recent years with more surgeons performing routine capsular closure. Management techniques and degree of capsular closure, however, can be quite variable between surgeons. This review will discuss hip capsular anatomy, the importance of the capsule in hip biomechanics, management of the capsule during arthroscopy, and functional outcomes as it relates to the various capsular closure techniques versus leaving the capsulotomy unrepaired.

Hypermobile Disorders and Their Effects on the Hip Joint

Hypermobility, or joint hyperlaxity, can result from inherited connective tissue disorders or from micro- or macrotrauma to a joint. The supraphysiologic motion of the hip joint results in capsuloligamentous damage, and these patients have a propensity to develop femoroacetabular impingement syndrome (FAIS) and labral injury. In this review, the recent literature evaluating the definitions, history, incidence, genetics, and histology of hypermobile disorders is investigated. We then review the clinical evaluation, natural history, and resulting instability for patients presenting with a hypermobile hip. Lastly, treatment options and outcomes will be highlighted.

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.

Mid-Term Outcomes of Combined Hip Arthroscopy and Limited Open Capsular Plication in the Non-Dysplastic Hip

BACKGROUND

Hip microinstability remains poorly-defined but increasingly diagnosed in the setting of borderline dysplasia (LCEA 20-25°), soft tissue laxity, or following unrepaired arthroscopic capsulotomy. While hip microinstability is com-monly treated with arthroscopic capsular plication with short-term outcomes reported, this procedure has been performed open for some time. The purpose of current study was to assess the durability of outcomes of combined arthroscopy and open capsular plication in treating symptomatic hip microinstability at mid-term follow-up.

METHODS

We retrospectively identified hips that underwent combined hip arthroscopy and open capsular plication for symptomatic microinstability between 2008 and 2013. Hips with excessive femoral anteversion (femoral version >35°) or classic acetabular dysplasia (LCEA <20°) were treated with bony reorientation and were not included in the current study. Patient reported outcomes scores were collected preoperatively and at a minimum five year follow-up. Hips that required reoperation or did not meet criteria for minimally clinically important difference (MCID, ≥8 increase in mHHS) or patient acceptable symptom scores (PASS, mHHS) were considered failures.

RESULTS

A total of 27 hips met criteria for inclusion and follow-up was obtained for 22 hips (81.5%) at a mean of 7.1 years. All patients were female with a mean age of 25.9 years and 7 (32%) hips had previous surgery. Patients undergoing the combined procedure improved from a mean baseline mHHS of 55.3±13 to a mean follow-up mHHS of 74.5±20.9 (p<0.001). At midterm follow-up, 54.5% of hips met criteria for PASS and 68.2% of hips met criteria for MCID, with 72.7% of hips meeting criteria for either MCID or PASS. Overall, 10 hips (45%) were considered failures with 6 hips (27%) requiring reoperation and an additional 4 hips (18%) with clinical failure. Hips without previous surgery had a failure rate of 33.3% (5/15) while 71.4% (5/7) of those with previous surgery failed (P=.09).

CONCLUSION

Our study demonstrates a high (45%) rate of reoperations and persistent symptoms in hips with microinstability treated with combined arthroscopy and open capsular plication. Further mid- and long-term studies evaluating soft tissue plication are needed, as well as comparisons with bony procedures in the setting of microinstability are needed.Level of Evidence: III.

Anteroinferior Hip Instability in Flexion During Dynamic Arthroscopic Examination Is Associated With Abnormal Anterior Acetabular Horn

Background:

The stabilization of the femoral head is provided by the distal acetabulum when the hip is in a flexed position. However, the osseous parameters for the diagnosis of hip instability in flexion are not defined.

Purpose/Hypothesis:

To determine whether the osseous parameters of the distal acetabulum are different in hips demonstrating anteroinferior subluxation in flexion under dynamic arthroscopic examination, compared with individuals without hip symptoms. The hypothesis was that the morphometric parameters of the anterior acetabular horn are distinct in hips with anteroinferior instability compared with asymptomatic hips.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 30 hips with anteroinferior instability in flexion under dynamic arthroscopic examination were identified. A control group of 60 hips (30 patients), matched by age and sex, was formed from individuals who had undergone pelvis magnetic resonance imaging (MRI) for nonorthopaedic reasons. Unstable and control hips were compared according to the following parameters assessed on axial MRI scans of the pelvis: anterior sector angle (ASA), anterior horn angle (AHA), posterior sector angle (PSA), posterior horn angle (PHA), acetabular version, lateral center-edge angle, acetabular inclination (Tönnis angle), and femoral head diameter.

Results:

The coverage of the femoral head by the anterior acetabular horn was decreased in unstable hips compared with the control group (mean ASA, 54.8° vs 61°, respectively; P < .001). Unstable hips also had a steeper anterior acetabular horn, with an increased mean AHA compared with controls (52.5° vs 46.8°, respectively; P < .001). An ASA <58° had a sensitivity of 0.8, a specificity of 0.68, a negative predictive value of 0.87, and a positive predictive value of 0.56 for anteroinferior hip instability. An AHA >50° had a sensitivity of 0.77, a specificity of 0.72, a negative predictive value of 0.86, and a positive predictive value of 0.57 for anteroinferior hip instability. There was no statistically significant difference in the mean PSA, PHA, acetabular version, lateral center-edge angle, acetabular inclination, or femoral head diameter between unstable hips and controls.

Conclusion:

Abnormal morphology of the anterior acetabular horn is associated with anteroinferior instability in hip flexion. The ASA and AHA can aid in the diagnosis of hip instability.

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.

Capsular thinning on magnetic resonance arthrography is associated with intra-operative hip joint laxity in women

Hip microinstability is a recognized cause of hip pain in young patients. Intra-operative evaluation is used to confirm the diagnosis, but limited data exist associating magnetic resonance arthrography (MRA) findings with hip microinstability. To determine if a difference exists in the thickness of the anterior joint capsule and/or the width of the anterior joint recess on MRA in hip arthroscopy patients with and without an intra-operative diagnosis of hip laxity. Sixty-two hip arthroscopy patients were included in the study. Two musculoskeletal radiologists blinded to surgical results reviewed the MRAs for two previously described findings: (i) anterior joint capsule thinning; (ii) widening of the anterior joint recess distal to the zona orbicularis. Operative reports were reviewed for the diagnosis of joint laxity. In all patients with and without intra-operative laxity, there were no significant differences with either MRA measurement. However, twenty-six of 27 patients with intra-operative laxity were women compared with 11 of 35 patients without laxity (P < 0.001). In subgroup analysis of women, the intra-operative laxity group had a higher rate of capsular thinning compared with the non-laxity group (85% versus 45%; P = 0.01). A 82% of women with capsular thinning also had intra-operative laxity, compared with 40% without capsular thinning (P = 0.01). There were no differences regarding the width of the anterior joint recess. In this study, there was an association between capsular thinning and intra-operative laxity in female patients. Measuring anterior capsule thickness on a pre-operative MRA may be useful for the diagnosis of hip microinstability.

Arthroscopic Ligamentum Teres Reconstruction: Minimum 2-Year Patient-Reported Outcomes With Subanalysis of Patients With Ehlers-Danlos Syndrome

PURPOSE

To report on minimum 2-year outcomes of patients undergoing arthroscopic ligamentum teres reconstruction (LTR).

METHODS

Our institutional registry was retrospectively reviewed for all patients undergoing LTR between December 2012 and February 2016. LTR was indicated for a fully torn or dysfunctional ligamentum teres with symptomatic multidirectional instability not treatable by osteotomy or capsular plication alone. Demographic data, preoperative clinical and radiographic measures, and intraoperative data were recorded. Patient-reported outcome measures including the modified Harris Hip Score, the Non-Arthritic Hip Score, a visual analog scale score for pain, and patient satisfaction were recorded preoperatively and annually postoperatively. Revision arthroscopies and conversions to total hip arthroplasty were recorded.

RESULTS

Twelve reconstruction procedures were performed in 10 patients during the study period. Minimum 2-year follow-up was available for 9 patients (11 hips). The mean follow-up time was 44.27 months (range, 24-72 months). There were 7 female and 2 male patients, and the mean age was 30.34 years (range, 17.23-43.68 years). Two hips underwent conversion to total hip arthroplasty at a mean of 21.12 months. For the remaining patients, significant improvements were observed in the modified Harris Hip Score (from 44.1 to 71.8), Non-Arthritic Hip Score (from 47.5 to 78.6), and visual analog scale score (from 7.8 to 3.6) (P < .05). The average patient satisfaction rating was 7.88 (range, 4-10). Subanalysis of 5 patients (7 hips) with a diagnosis of Ehlers-Danlos syndrome showed a higher failure rate in this group.

CONCLUSIONS

Although LTRs are indicated and performed only in a select group of patients, the procedure can provide meaningful improvement in patient-reported outcomes, pain reduction, and patient satisfaction. However, most patients undergoing LTR at present have underlying factors that significantly mitigate their prognosis, such as Ehlers-Danlos syndrome or failed previous surgery. Because these patients represent a subset of patients with complex hip pathologies in whom treatment is difficult, the expectations of surgery should be set accordingly.

LEVEL OF EVIDENCE

Level IV, therapeutic study, case series.

Editorial Commentary: "Loose Lips Sink Ships"-But What About "Loose Hips"?

Hip instability continues to be a challenge in hip preservation. Our understanding of the role of osseous anatomy, labral integrity and soft-tissue stabilizers has increased dramatically over the past several decades. Connective-tissue disorders such as Ehlers-Danlos syndrome pose a significant challenge to the management of instability in all joints but particularly in the hip. Ligamentum teres tears have been found to be more common than previously thought, although their significance is still not well understood. In patients with both Ehlers-Danlos syndrome and ligamentum teres tears, reconstruction and capsular plication result in moderate success, but not in all cases.

Primary Total Hip Arthroplasty in Patients With Ehlers-Danlos Syndrome: A Retrospective Matched-Cohort Study

Background

Ehlers-Danlos syndromes (EDSs) are connective-tissue disorders resulting in joint laxity. Soft-tissue stability is a concern in these patients when they undergo total hip arthroplasty (THA). Our purpose was to compare THAs in the population with EDS with a matched control undergoing THA for osteoarthritis.

Methods

Thirteen patients with EDS underwent THA from 1997 to 2017. Matching was 1:3 with a control group of patients who underwent THA for osteoarthritis. Matching was based on the gender, age, and length of follow-up.

Results

We found no difference in demographics or postoperative Harris Hip Scores between the cohorts (P > .05). Two patients (15.4%) with EDS and 2 patients (5.1%) in the control group suffered a dislocation. We found no difference in the reoperation or revision rate between the groups (P = .28).

Conclusion

Patients with EDS have a significant improvement in postoperative Harris Hip Scores after THA. These patients also have a high dislocation rate after surgery, and alternative approaches and technologies such as dual-mobility components should be considered to reduce the rate of dislocation in this population.

Achieving Successful Outcomes of Hip Arthroscopy in the Setting of Generalized Ligamentous Laxity With Labral Preservation and Appropriate Capsular Management: A Propensity Matched Controlled Study

BACKGROUND

Association among generalized ligamentous laxity (GLL), hip microinstability, and patient-reported outcomes (PROs) after hip arthroscopy has yet to be completely established.

PURPOSES

(1) To report minimum 2-year PROs in patients with GLL who underwent hip arthroscopy in the setting of symptomatic labral tears and femoroacetabular impingement syndrome and (2) to compare clinical results with a matched-pair control group without GLL.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from a prospectively collected database were retrospectively reviewed between August 2014 and December 2016. Patients were considered eligible if they received primary arthroscopic treatment for symptomatic labral tears and femoroacetabular impingement. Inclusion criteria included preoperative and minimum 2-year follow-up scores for the following PROs: modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), and visual analog scale for pain (VAS). From the sample population, 2 groups were created: the GLL group (Beighton score ≥4) and the control group (Beighton score <4). Patients were matched in a 1:2 ratio via propensity score matching according to age, sex, body mass index, Tönnis grade, and preoperative lateral center-edge angle. Patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID) for mHHS, Hip Outcome Score-Sports Specific Scale (HOS-SSS), and International Hip Outcome Tool-12 (iHOT-12) were calculated.

RESULTS

A total of 57 patients with GLL were matched to 88 control patients. Age, sex, body mass index, and follow-up times were not different between groups (P > .05). Preoperative radiographic measurements demonstrated no difference between groups. Intraoperative findings and procedures between groups were similar except for capsular treatment, with the GLL group receiving a greater percentage of capsular plications (P = .04). At minimum 2-year follow-up, both groups showed significant improvement in PROs and VAS (P < .001). Furthermore, the postoperative PROs at minimum 2-year follow-up and the magnitude of improvement (delta value) were similar between groups for mHHS, NAHS, HOS-SSS, and VAS (P > .05). Moreover, groups reached comparable rates of MCID and PASS for mHHS, HOS-SSS, and iHOT-12.

CONCLUSION

Patients with GLL after hip arthroscopy for symptomatic femoroacetabular impingement and labral tears may expect favorable outcomes with appropriate labral and capsular management at minimum 2-year follow-up. When compared with a pair-matched control group without GLL, results were comparable for mHHS, NAHS, HOS-SSS, and VAS and reached PASS and/or MCID for mHHS, HOS-SSS, and iHOT-12.

The dimensions of the hip capsule can be measured using magnetic resonance imaging and may have a role in arthroscopic planning

PURPOSE

The purpose of this study was to systematically evaluate the dimensions and thickness of the hip joint capsule. Secondarily, the study assessed whether there were any described correlations between capsule thickness and stability of the hip joint.

METHODS

Four databases (PubMed, Ovid [MEDLINE], Cochrane Database, and EMBASE) were searched from database inception to May 2018, and two reviewers independently and in duplicate screened the resulting literature. Methodological quality of all included papers was assessed using the Methodological index for non-randomized studies (MINORS) criteria. Mean differences were combined in a meta-analysis using a random effects model when possible.

RESULTS

A total of 14 studies (1 level I, 1 level II, 4 level III, 5 level IV) were identified including 796 patients (1013 hips) with a mean age of 39.5 years (range 2-95). Of the included patients, 55.2% were female and they were followed up for a mean of 7.6 months (range 1-12.5 months). The thickness of the capsule was measured in cadaveric specimens, ultrasound, and magnetic resonance imaging (MRI), with MRI measurements reported most consistently and with the least variation. Mean thickness of the anterior capsule in patients without hip disease on MRI ranged from 4.4 and 4.7 mm. Mean thickness of the anterior capsule in patients with FAI ranged between 4.9 and 5.0 mm. Males had significantly thicker capsules than females (mean difference = 1.92 mm, 0.35-3.49, P = 0.02). Clinical laxity of the hip joint, as well as female gender was correlated with thinner anterior joint capsules.

CONCLUSION

The thickness of the anterior hip capsule can be measured consistently using MRI. A thinner anterior capsule may be associated with clinical laxity of the hip joint. The relevance of capsular thickness on postoperative instability following hip arthroscopy is poorly understood and warrants further investigation. The thickness of the anterior hip capsule, as measured on MRI, has the potential to be used as part of the clinical decision-making in capsular management strategies.

LEVEL OF EVIDENCE

IV.

Revision Hip Capsular Repair and Augmentation With a Bioinductive Implant After a Post-arthroscopy Hip Subluxation Event

In the past decade, the number of hip arthroscopy procedures has exponentially increased, primarily for the treatment of femoroacetabular impingement syndrome and labral lesions. As the techniques have evolved, so has the acknowledgment of the potential complications, including iatrogenic instability that may result from soft-tissue laxity, subtle dysplastic morphologies, or residual defects from capsulotomies in which the capsular closure is insufficient. In most cases, direct capsular repair or plication can be performed at the conclusion of the procedure; however, larger defects, poor-quality tissue, or cases of gross ligamentous laxity may require reconstruction or augmentation. In such instances, several options exist. The purpose of this technical note is to describe a capsular repair augmentation with a bioinductive implant during revision hip arthroscopy.

Contributions of the Capsule and Labrum to Hip Mechanics in the Context of Hip Microinstability

Background

Hip microinstability and labral pathology are commonly treated conditions with increasing research emphasis. To date, there is limited understanding of the biomechanical effects of the hip capsule and labrum on controlling femoral head motion.

Purpose/Hypothesis

The purpose of this study was to determine the relative role of anterior capsular laxity and labral insufficiency in atraumatic hip microinstability. Our hypotheses were that (1) labral tears in a capsular intact state will have a minimal effect on femoral head motion and (2) the capsule and labrum work synergistically in controlling hip stability.

Study Design

Controlled laboratory study.

Methods

Twelve paired hip specimens from 6 cadaveric pelvises (age, 18-41 years) met the inclusion criteria. Specimens were stripped of all soft tissue except the hip capsule and labrum, then aligned, cut, and potted using a custom jig. A materials testing system was used to cyclically stretch the anterior hip capsule in extension and external rotation, while rotating about the mechanical axis of the hip. Labral insufficiency was created with a combined radial and chondrolabral tear under direct visualization. A motion tracking system was used to record hip internal-external rotation and displacement of the femoral head relative to the acetabulum in the anterior-posterior, medial-lateral, and superior-inferior directions. Testing variables included baseline, postventing, postcapsular stretching, and postlabral insufficiency.

Results

When comparing the vented state with each experimental pathologic state, increases in femoral head motion were noted in both the capsular laxity state and the labral insufficiency state. The combined labral insufficiency and capsular laxity state produced statistically significant increases (P < .001) in femoral head translation compared with the vented state in all planes of motion.

Conclusion

Both the anterior capsule and labrum play a role in hip stability. In this study, the anterior hip capsule was the primary stabilizer to femoral head translation, but labral tears in the setting of capsular laxity produced the most significant increases in femoral head translation.

Clinical Relevance

This study provides a physiologic biomechanical assessment of the hip constraints in the setting of hip microinstability. It also sheds light on the importance of the hip capsule in the management of labral tears. Our study demonstrates that labral tears in isolation provide minimal changes in femoral head translation, but in the setting of a deficient capsule, significant increases in femoral head translation are seen, which may result in joint-related symptoms.

Anterior Capsule Reconstruction of the Native Hip: A Technique Guide

This is a technique guide for open anterior capsule reconstruction in unstable native hips due to Ehlers-Danlos syndrome. Ehlers-Danlos syndrome is a connective tissue disease that predisposes an individual to hypermobility of their soft tissues and recurrent subluxations and dislocations of their joints. This may lead to constant instability, guarding of the hip, and subsequent arthritic changes and poor quality of life. We demonstrate anterior capsule reconstruction of the hip using an Achilles tendon allograft performed through a direct anterior approach to the hip (Heuter's approach). This technique guide outlines in detail the surgical steps required to accomplish this reconstructive procedure. Furthermore, a narrated surgical video is provided that clearly depicts the anticipated result of the increased constrained provided to the hip from the anterior capsule reconstruction using an Achilles tendon allograft.

The Role of Anterior Capsular Laxity in Hip Microinstability: A Novel Biomechanical Model

BACKGROUND

Hip microinstability is an increasingly recognized source of hip pain and disability. Although the clinical entity has been well described, the pathomechanics of this disease remain poorly understood.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine the role of capsular laxity in atraumatic hip microinstability. Our hypothesis was that cyclic stretching of the anterior hip capsule would result in increased hip range of motion and femoral head displacement.

STUDY DESIGN

Controlled laboratory study.

METHODS

In this study, 7 hip specimens met inclusion criteria (age, 18-46 years). Specimens were stripped of all soft tissue, aligned, cut, and potted by use of a custom jig. A materials testing system was used to cyclically stretch the anterior hip capsule in extension and external rotation while rotating about the mechanical axis of the hip. A motion tracking system was used to record hip rotation and displacement of the femoral head relative to the acetabulum in the anterior-posterior, medial-lateral, and superior-inferior directions. Testing was conducted at baseline, after venting, and after capsular stretching.

RESULTS

With the hip in anatomic neutral alignment, cyclic stretching of the anterior hip capsule resulted in increased hip rotation ( P < .001). Femoral head displacement significantly increased relative to the vented state in the medial-lateral ( P < .001), anterior-posterior ( P = .013), and superior-inferior ( P = .036) planes after cyclic stretching of the anterior hip capsule.

CONCLUSION

The anterior hip capsule plays an important role in controlling hip rotation and femoral head displacement. This study is the first to display significant increases in femoral head displacement through a controlled cyclic stretching protocol of the anterior hip capsule.

CLINICAL RELEVANCE

This study is directly applicable to the treatment of atraumatic hip microinstability. The results quantitatively define the relative importance of the hip capsule in controlling femoral head motion. This allows for a better understanding of the pathophysiological process of hip microinstability and serves as a platform to develop effective surgical techniques for treatment of this disease.

Upsloping lateral sourcil: a radiographic finding of hip instability

While radiographic findings of frank hip dysplasia are well defined, there is a lack of diagnostic criteria for patients with radiographically ‘normal’ hips who have borderline morphologic deficits and clinical instability. In this study, we aim to define and validate a new radiographic finding associated with hip instability known as the upsloping lateral sourcil (ULS). Patients (316) were reviewed for lateral center edge angles, generalized joint laxity assessed with the Beighton Hypermobility Score and the presence of the ULS. The ULS was defined as a caudal-to-cranial inclination of the middle-to-far lateral aspect of the acetabular sourcil with loss of the normal lateral acetabular concavity. The prevalence of the ULS correspondingly increased with the degree of under-coverage as defined by LCEA. Within the normal coverage group, hips with a ULS had smaller LCEAs than those without ULS (29° versus 32°, P < 0.001). Among hips with a ULS, 59.00% had generalized joint laxity. The association between the ULS finding and generalized joint laxity was statistically significant (P < 0.01). The ULS is seen with higher prevalence in patients with clinical hip laxity and radiographically decreasing LCEA and may serve as an adjunctive finding in patients presenting with hip pain and instability. The ULS may help to characterize patients with borderline hip dysplasia and laxity that fall outside conventional imaging criteria for dysplasia.

The Cliff Sign: A New Radiographic Sign of Hip Instability

Background:

The preoperative diagnosis of hip microinstability is challenging. Although physical examination maneuvers and magnetic resonance imaging findings associated with microinstability have been described, there are limited reports of radiographic features. In patients with microinstability, we observed a high incidence of a steep drop-off on the lateral edge of the femoral head, which we have named the “cliff sign.”

Purpose:

(1) To determine the relationship of the cliff sign and associated measurements with intraoperative microinstability and (2) to determine the interobserver reliability of these measurements.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

A total of 115 consecutive patients who underwent hip arthroscopy were identified. Patients with prior hip surgery, Legg-Calve-Perthes disease, fractures, pigmented villonodular synovitis, or synovial chondromatosis were excluded, resulting in the inclusion of 96 patients in the study. A perfect circle around the femoral head was created on anteroposterior pelvis radiographs. If the lateral femoral head did not completely fill the perfect circle, it was considered a positive cliff sign. Five additional measurements relating to the cliff sign were calculated. The diagnosis of microinstability was made intraoperatively by the (1) amount of traction required to distract the hip, (2) lack of hip reduction after initial traction release following joint venting, or (3) intraoperative findings consistent with hip microinstability. Continuous variables were analyzed through use of unpaired t tests and discrete variables with Fisher exact tests. Interobserver reliability (n = 3) was determined for each measurement.

Results:

Overall, 89% (39/44) of patients with microinstability had a cliff sign, compared with 27% of patients (14/52) without instability (P < .0001). Conversely, 74% of patients with a cliff sign had microinstability, while only 12% of patients without a cliff sign had instability (P < .0001). In women younger than 32 years with a cliff sign, 100% (20/20) were diagnosed with instability. No differences were found in any of the 5 additional measurements. Excellent interobserver reliability was found for the presence of a cliff sign and the cliff angle measurement.

Conclusion:

We have identified a radiographic finding, the cliff sign, that is associated with the intraoperative diagnosis of hip microinstability and has excellent interobserver reliability. Results showed that 100% of young women with a cliff sign had intraoperative microinstability. The cliff sign may be useful in the preoperative diagnosis of hip microinstability.

Progressive osteoarthritis during pregnancy several years following hip arthroscopy for femoroacetabular impingement

Case

A 28-year-old with borderline left hip dysplasia who underwent arthroscopic acetabuloplasty, femoral osteochondroplasty, and labral repair for femoroacetabular impingement. She did well for 8 years, though required arthroscopic capsulolabral adhesion release 2 years after the initial procedure. After this period of stability, she developed left hip pain during pregnancy. Radiographs demonstrated progressive osteoarthritis that lead to total hip arthroplasty at age 37.

Conclusion

The physiologic and hormonal changes during pregnancy leading to increased ligamentous laxity may put vulnerable patients with hip dysplasia and iatrogenic instability at increased risk for progression of osteoarthritis.

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.

Do Ligamentum Teres Tears Portend Inferior Outcomes in Patients With Borderline Dysplasia Undergoing Hip Arthroscopic Surgery? A Match-Controlled Study With a Minimum 2-Year Follow-up

BACKGROUND

Arthroscopic surgery in borderline dysplastic hips remains controversial, but the role of the ligamentum teres (LT) has not been studied in this setting.

HYPOTHESIS

Borderline dysplastic patients with LT tears have worse short-term outcomes than those without LT tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected on patients who underwent arthroscopic surgery between February 2008 and April 2014. The inclusion criteria were borderline dysplasia (lateral center-edge angle [LCEA], 18°-25°) and labral tears; arthroscopic treatments including labral preservation and capsular plication; and preoperative patient-reported outcome scores including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale, and visual analog scale for pain. Patients were excluded for preoperative Tönnis osteoarthritis grade >0, workers' compensation claims, previous ipsilateral hip surgery and conditions, or frank dysplasia (LCEA <18°). Patients with LT tears were pair-matched to patients without tears for sex, age at surgery ±10 years, body mass index (<30 kg/m² vs ≥30 kg/m²), labral treatment type, and microfracture.

RESULTS

Of 68 eligible patients, 63 (93%) had a minimum 2-year follow-up, and 30 (48%) had LT tears. Twenty patients in each group were pair-matched. The mean follow-up time was 54.3 months (range, 24.2-83.8 months) for the LT tear group and 38.6 months (range, 24.6-70.6 months) for the control group ( P = .002). Ninety percent were female. There were no significant differences regarding demographics or intra-operative procedures. The LT tear group trended toward lower postoperative mHHS ( P = .09) and NAHS ( P = .09) values. Mean satisfaction was 8.1 for the LT tear group and 7.9 for the control group. Preoperative and follow-up scores were not significantly different between the groups. The LT tear group had 5 revisions, with 1 revision in the control group. Three patients (15%) in the LT tear group underwent total hip arthroplasty (THA); no patients in the control group required THA.

CONCLUSION

In borderline dysplastic patients undergoing hip arthroscopic surgery with labral treatment and capsular plication, LT tears may indicate advanced instability and portend slightly inferior outcomes when compared with a match-controlled group. Borderline dysplastic patients with LT tears may have increased propensities toward revision arthroscopic surgery and conversion to THA. LT tears in these patients may warrant consideration for additional procedures including periacetabular osteotomy and LT reconstruction.

Musculoskeletal Conditions in a Pediatric Population with Ehlers-Danlos Syndrome

OBJECTIVE

To describe musculoskeletal conditions in children with Ehlers-Danlos syndrome (EDS).

STUDY DESIGN

A retrospective medical record review was performed, which evaluated 205 patients with EDS (ages 6-19 years) seen in sports medicine or orthopedic clinic at a large pediatric hospital over a 5-year period.

RESULTS

Female (n = 147) and male (n = 57) patients were identified (mean age 12.7 years). The most common EDS subtype (55.6%) was hypermobility type. Patients had between 1 and 69 visits (median 4), and 764 diagnoses were recorded, most commonly laxity/instability, pain, subluxation, and scoliosis/spinal asymmetry. Nearly one-half of patients (46.8%) received a general diagnosis of pain because no more specific cause was identified, in addition to 8.3% who were diagnosed with chronic pain syndrome. The most common sites of presenting issue were knee (43.4%), back (32.2%), and shoulder (31.2%). Over three-fourths (77.1%) of patients had imaging. Most (88.1%) were prescribed physical therapy and/or other conservative measures, such as rest (40.5%), orthotics (35.6%), and medication (32.2%). Surgery was recommended to 28.8% of the study population.

CONCLUSIONS

Many pediatric and adolescent patients with EDS experience joint pain, instability, and scoliosis, along with other musculoskeletal issues. Despite extensive workup, the etiology of pain may not be identified. Large numbers of office visits, imaging studies, treatment prescriptions, and specialist referrals indicate considerable use of medical resources and highlight a great need for injury prevention and additional study.

Hip arthroscopic capsulotomy techniques and capsular management strategies: a systematic review

PURPOSE

Hip arthroscopy is increasingly used to address hip joint pathology. Iatrogenic instability has been reported as a potential complication, leading to the evaluation of various capsular management strategies. The purpose of this review was to (1) report the techniques used for capsulotomy in hip arthroscopy, (2) understand techniques and indications for capsular closure, and (3) report outcomes based on capsular management strategy.

METHODS

MEDLINE, EMBASE, and PubMed were searched and screened in duplicate for relevant studies. Data regarding patient demographics, indications, surgical technique, rehabilitation strategies, and complication rates were obtained. Study quality was assessed in duplicate using the Methodological Index for Non-Randomized Studies (MINORS) Criteria.

RESULTS

Eighty-two studies of primarily level IV evidence (80 %) and of fair quality involving 4504 patients with a mean age of 35 years old (range 1.2-82 years) were included. Fifty percent of patients were male. Mean follow-up was 24.9 months (range 5 days to 13 years). Of 68 studies reporting capsulotomy technique (only 7 % of all otherwise eligible studies), 55 % performed an interportal capsulotomy while 24 % performed a T-capsulotomy. Of 36 studies reporting capsular management strategy post-arthroscopy, 22 % did not repair the capsulotomy, 6 % routinely performed partial repair, and 50 % performed complete repair. Of three studies (206 patients) directly comparing capsular management strategies, only one study found a statistically significant difference between complete and partial repair on the Hip Outcome Score-Sport Specific Subscale, though this difference was less than the minimal clinically important difference (83.6 versus 87.3). The total rate of reported post-operative dislocation, instability, or instability was 0.3 % (5 patients).

CONCLUSIONS

Technical details regarding capsulotomy and capsular management post-hip arthroscopy are not consistently reported in the literature. Capsulotomies are most often performed using an interportal technique, and more recent studies report routine closure. Overall, post-operative instability is rare and there is no consistent trend for capsular management strategy. Given current evidence, there is little basis on which to establish the relationship between surgical technique and post-operative instability or long-term consequences (e.g., kinematic changes). Thus, while capsular closure/plication may be suitable for specific populations (i.e., dysplasia or laxity), evidence-based indications for capsular repair remain unclear.

LEVEL OF EVIDENCE

Level IV, systematic review of level I-IV Studies.