Hip stability after ligamentum teres resection during surgical dislocation for cam impingement

Ligamentum Teres Tears and Increased Combined Anteversion Are Associated With Hip Microinstability in Patients With Borderline Dysplasia

PURPOSE

To investigate the differences in the prevalence of ligamentum teres (LT) tears and other radiographic measurements in borderline dysplasia of the hip (BDDH) with/without microinstability and to evaluate the associations between these imaging findings and the prevalence of microinstability in patients with BDDH.

METHODS

This was a retrospective study of symptomatic patients with BDDH (18° ≤ lateral center-edge angle <25°) treated with arthroscopy in our hospital between January 2016 and December 2021. These patients were divided into the BDDH with microinstability (mBDDH) group and the stable BDDH (nBDDH) group. The radiographic parameters associated with hip joint stability, such as the state of LT, acetabular versions, femoral neck version, Tönnis angle, combined anteversions, and anterior/posterior acetabular coverage, were reviewed and analyzed.

RESULTS

There were 54 patients (49 female/5 male, 26.7 ± 6.9 years) in the mBDDH group and 81 patients (74 female/7 male, 27.2 ± 7.7 years) in the nBDDH group. The mBDDH group had greater LT tear (43/54 vs 5/81) and general laxity rates, increased femoral neck version, acetabular version and combined anteversion (52.4 ± 5.9 vs 41.5 ± 7.1 at 3-o'clock level) than the nBDDH group. Binary logistic regression showed that LT tears (odds ratio 6.32, 95% confidence interval 1.38-28.8; P = .02; R2 = .458) and combined anteversion at the 3-o'clock level (odds ratio 1.42, 95% confidence interval 1.09-1.84; P < .01; R2 = .458) were independent predictors of microinstability in patients with BDDH. The cutoff value of combined anteversion at 3-o'clock level was 49.5°. In addition, LT tear was correlated with increased combined anteversion at 3-o'clock level in patients with BDDH (P < .01, η2 = 0.29).

CONCLUSIONS

LT tears and increased combined anteversion at the 3-o'clock level on the acetabular clockface were associated with hip microinstability in patients with BDDH, suggesting that patients with BDDH and LT tears might have a greater prevalence of anterior microinstability.

LEVEL OF EVIDENCE

Level III, case‒control study.

Open and arthroscopic management of femoroacetabular impingement: a review of current concepts

Femoroacetabular impingement (FAI) is a common femoral and/or acetabular abnormality that can cause progressive damage to the hip and osteoarthritis. FAI can be the result of femoral head/neck overgrowth, acetabular overgrowth or both femoral and acetabular abnormalities, resulting in a loss of native hip biomechanics and pain upon hip flexion and rotation. Radiographic evidence can include loss of sphericity of the femoral neck (cam impingement) and/or acetabular retroversion with focal or global overcoverage (pincer impingement). Operative intervention is indicated in symptomatic patients after failed conservative management with radiographic evidence of impingement and minimal arthritic changes of the hip, with the goal of restoring normal hip biomechanics and reducing pain. This is done by correcting the femoral head-neck relationship to the acetabulum through femoral and/or acetabular osteoplasty and treatment of concomitant hip pathology. In pincer impingement cases with small lunate surfaces, reverse periacetabular osteotomy is indicated as acetabular osteoplasty can decrease an already small articular surface. While surgical dislocation is regarded as the traditional gold standard, hip arthroscopy has become widely utilized in recent years. Studies comparing both open surgery and arthroscopy have shown comparable long-term pain reduction and improvements in clinical measures of hip function, as well as similar conversion rates to total hip arthroplasty. However, arthroscopy has trended toward earlier improvement, quicker recovery and faster return to sports. The purpose of this study was to review the recent literature on open and arthroscopic management of FAI.

Hip preservation surgery and the acetabular fossa

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells.

Cite this article: Bone Joint Res 2020;9(12):857–869.

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.

Ligamentum teres reconstruction: indications, technique and minimum 1-year results in nine patients

Ligamentum teres (LT) tear is a recognized cause of hip pain. Debridement of tears and capsule plication has shown satisfactory results. However, a group of patients with complete tears do not improve after debridement and physiotherapy. The purpose of this work was to describe the senior author's technique and clinical results for the early series of LT reconstructions. Retrospective analysis of prospectively collected data. Patients who underwent isolated LT reconstruction between 2013 and 2018. All the patients had previous debridement of a completely torn LT, capsule plication and rehabilitation. Patients who had any other associated procedure during LT reconstruction surgery and dysplastic acetabular features were excluded. Demographic and clinical data was reviewed. Complications, type of graft and modified Harris hip scores (mHHSs) were recorded preoperatively and at 1-year follow-up. Fifteen LT reconstructions were performed during the study period. Six were excluded (as they had additional procedures performed during surgery) and nine patients aged a mean 30 (range: 22-48) years old were included. The patients had a mean of 2 (range: 1-4) prior surgeries. At minimum 12 months (range: 12-24) 9/9 patients reported reduction of pain and instability symptoms with mHHSs of 84.2 (73.7-100) versus 51.7 (36.3-70.4) preoperatively (P = 0.00094). Three patients (of the total cohort of 15) underwent second-look arthroscopy (11-22 months after reconstruction). None of these patients underwent total hip replacement at a mean of 4 (range: 1-6) years. Arthroscopic LT reconstruction improved function and pain in patients with persistent pain and instability after resection of the LT.

CLINICAL RELEVANCE of the LIGAMENTUM TERES: A LITERATURE REVIEW

Background

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Level of Evidence

3.

[Surgical hip dislocation : Current status in the treatment of femoral acetabular impingement]

INTRODUCTION

Surgical hip dislocation (SHD) in the therapy of femoral acetabular impingement (FAI) has been mostly replaced by minimally invasive techniques. Nevertheless, in the circumstances of complex FAI types and combined impingement located in inaccessible areas of the hip, SHD is an option to reach those deformities. The advantage of the complete overview of the hip joint enables the circumferential therapy of bony deformity, but at the expense of higher invasivity. In the literature there is still a lack of mid to long-term studies of SHD to determine the overall treatment outcome. Therefore, the aim of this study is to evaluate the treatment outcome, risks and complications of SHD in FAI therapy within a mid-term follow-up.

METHODS

A total of 43 patients (mean follow-up 54 months.) with combined ventral and dorsal impingement who undertook SHD were retrospectively reviewed. Outcome parameters were range of motion (ROM), the Harris hip score (HHS), the hip outcome score (HOS), the activity level, pain, complications, conversion to total hip arthroplasty (THA) and patient specific surveys. Additionally, radiographs and the influence of preoperative osteoarthrosis were evaluated.

RESULTS

We were able to demonstrate a significant increase of ROM, HHS (69 → 80 Pkt.; p < 0.05), hip function and a decrease in pain level. The return to sport rate was 81%, but in most cases the patients had to reduce the intensity or change to a low impact sport activity. Overall, 75% were satisfied with the treatment outcome. The alpha angle improved from 70 to 45° (p < 0.05). Patients with preoperatively advanced hip osteoarthrosis showed no decent improvement of hip function. Conversion to THA was necessary in 36% of cases. The complication rate was about 13%.

CONCLUSION

SHD is successful in the treatment of combined ventral and dorsal impingement within a mid-term follow-up. The improvement of hip function and the reduction of pain symptoms is possible. In case of a manifest arthrosis an indication for SHD is no longer reasonable.

Atraumatic Hip Instability

Atraumatic hip instability is an increasingly recognized source of pain and hip dysfunction. It can result from numerous causes, including femoroacetabular impingement, prior trauma, injury to the capsuloligamentous structures, and idiopathic etiologies. Occult hip instability can be a challenging diagnosis that requires careful attention to, and interpretation of, history, physical examination, and radiographic imaging findings. Iatrogenic hip instability is a potential complication of both open and arthroscopic hip-preserving surgical procedures that can have catastrophic results. Atraumatic hip instability is a pathologic entity that can be successfully addressed with open and arthroscopic procedures.

The role of the ligamentum teres in the adult hip: redundant or relevant? A review

The ligamentum teres (LT) has traditionally been described as a redundant structure with no contribution to hip biomechanics or function. There has been renewed interest in the LT as a source of hip pathology due to the high prevalence of LT pathology observed at the time of hip arthroscopy. The LT acts a secondary stabilizer to supplement the work of the capsular ligaments and works in a sling-like manner to prevent subluxation of the hip at the extremes of motion. The presence of free nerve endings within the LT indicates a definite role in pain generation, with the LT undergoing various mechanical and histological adaptations to hip pathology.

A Modification of the Dunn Osteotomy With Preservation of the Ligamentum Teres

BACKGROUND

We aimed to determine if a modified Dunn osteotomy could be safely performed without surgical dislocation and consequent preservation of the ligamentum teres.

METHODS

All patients undergoing a modified Dunn osteotomy for a slipped capital femoral epiphysis over an 8-year period were included in this study, and all had a severe slip with an open physis.

RESULTS

The modified Dunn procedure was performed on 34 hips in 34 patients. The mean age was 13.1 years (range, 11 to 16 y) with a mean follow-up time of 54 months (range, 15 to 102 mo). All slips were severe (grade 3) with a mean slip angle of 73.2 degrees (range, 60 to 90 degrees). Nineteen slips were stable and 15 were unstable. Of the unstable slips, the average time from initial presentation to the emergency department until surgery was 9.4 days (range, 2 to 42 d). Excluding 1 patient who developed complete collapse of the femoral head (NAHS 56), the average Nonarthritic Hip score was 98 (range, 93.7 to 100). Four (11.8%) patients developed avascular necrosis of the femoral head, of which 3 were unstable slips.

CONCLUSIONS

A modified Dunn osteotomy with preservation of the ligamentum teres allows an excellent restoration of the anatomic alignment of the femoral head and neck. Rates of AVN are not increased compared with other techniques of subcapital osteotomy but this complication cannot be eliminated particularly in patients with unstable slips.

LEVEL OF EVIDENCE

Level III.

Editorial Commentary: Ligamentum Teres Tears and Femoroacetabular Impingement: Complex Coexistence of Impingement and Instability

In a large Level IV case series of 2,213 hip arthroscopies with the diagnosis of femoroacetabular impingement, the intraoperative status of the ligamentum teres (LT) was recorded as normal in 11%, frayed and/or partially torn in 88%, and completely torn in 1.5% of hips. Although specific physical examination maneuvers for detecting LT tears were not available early in the study period, thus limiting a detailed assessment of such tests, the authors identified that female gender, a lower lateral center edge angle, a higher Tonnis angle, and capsular laxity were all associated with complete LT tears. This study further supports the complex coexistence of impingement and instability.

Atraumatic tears of the ligamentum teres are more frequent in professional ballet dancers than a sporting population

OBJECTIVES

To compare the frequency of atraumatic ligamentum teres (LT) tear in professional ballet dancers with that of athletes, and to determine the relationship with clinical and imaging findings.

METHODS

Forty-nine male and female professional ballet dancers (98 hips) and 49 age and sex-matched non-dancing athletes (98 hips) completed questionnaires on hip symptoms and physical activity levels, underwent hip rotation range of movement (ROM) and hypermobility testing, and 3.0-Tesla magnetic resonance imaging (3 T MRI) on both hips to detect LT tears, acetabular labral tears, and articular cartilage defects, and to measure the lateral centre edge angles (LCE).

RESULTS

A higher frequency of LT tear was found in dancers (55 %) compared with athletes (22 %, P = 0.001). The frequency and severity of LT tears in dancers increased with older age (P = 0.004, P = 0.006, respectively). The Hip and Groin Outcome Score (HAGOS) pain scores or hip rotation ROM did not differ significantly among participants with normal, partial, or complete tears of LT (P > 0.01 for all). Neither the frequency of generalised joint hypermobility (P = 0.09) nor the LCE angles (P = 0.32, P = 0.16, left and right hips respectively) differed between those with and those without LT tear. In most hips, LT tear co-existed with either a labral tear or a cartilage defect, or both.

CONCLUSION

The higher frequency of atraumatic LT tears in professional ballet dancers suggests that the LT might be abnormally loaded in ballet, and caution is required when evaluating MRI, as LT tears may be asymptomatic. A longitudinal study of this cohort is required to determine if LT tear predisposes the hip joint to osteoarthritis.

The capsular ligaments provide more hip rotational restraint than the acetabular labrum and the ligamentum teres : an experimental study

In this in vitro study of the hip joint we examined which soft tissues act as primary and secondary passive rotational restraints when the hip joint is functionally loaded. A total of nine cadaveric left hips were mounted in a testing rig that allowed the application of forces, torques and rotations in all six degrees of freedom. The hip was rotated throughout a complete range of movement (ROM) and the contributions of the iliofemoral (medial and lateral arms), pubofemoral and ischiofemoral ligaments and the ligamentum teres to rotational restraint was determined by resecting a ligament and measuring the reduced torque required to achieve the same angular position as before resection. The contribution from the acetabular labrum was also measured. Each of the capsular ligaments acted as the primary hip rotation restraint somewhere within the complete ROM, and the ligamentum teres acted as a secondary restraint in high flexion, adduction and external rotation. The iliofemoral lateral arm and the ischiofemoral ligaments were primary restraints in two-thirds of the positions tested. Appreciation of the importance of these structures in preventing excessive hip rotation and subsequent impingement/instability may be relevant for surgeons undertaking both hip joint preserving surgery and hip arthroplasty.

Cite this article: Bone Joint J 2015; 97-B:484–91.

Ligamentum teres injuries of the hip: a systematic review examining surgical indications, treatment options, and outcomes

PURPOSE

Hip arthroscopy is becoming a common technique for the diagnosis and treatment of ligamentum teres pathologic conditions. This systematic review aims to determine the indications/contraindications, treatments, and surgical outcomes for management of ligamentum teres injuries.

METHODS

We searched EMBASE, MEDLINE, and PubMed databases from 1946 to November 28, 2013 for all relevant English articles pertaining to surgical treatment of the ligamentum teres. A hand search of the reference sections of included articles was performed, and all relevant articles were systematically screened in duplicate, with agreement and descriptive statistics presented.

RESULTS

We identified 1,016 studies, 9 of which (4 case series and 5 case reports) met our eligibility criteria. These studies had a total of 87 patients (89 hips) who had undergone either arthroscopic debridement (81 patients, 83 hips) or reconstruction with autografting, allografting, or synthetic grafting (6 patients) of a torn ligamentum teres. Major qualifications for surgery included persistent hip pain despite conservative treatment and mechanical symptoms or instability symptoms (e.g., clicking or locking). Advanced arthritis (i.e., radiographic joint space < 2 mm) was the only reported contraindication. Patients were followed postoperatively for 1.5 to 60 months and were assessed using subjective methods (i.e., modified Harris Hip Score [mHHS] and Non-Arthritic Hip Score [NAHS]). Overall, both debridement and reconstruction improved the condition of patients, with a 40% increase in reported postoperative functional scores as well as a reported 89% of patients who were able to return to regular activity/sport.

CONCLUSIONS

Ligamentum teres debridement is indicated for short-term relief of hip pain caused by partial-thickness tears (type 2) failing conservative management, whereas reconstruction with autografts, allografts, or synthetic grafts may be indicated for type 1 (full-thickness) ligamentum teres tears that are deemed "reparable," cause instability, have failed previous debridement, or a combination of these conditions.

LEVEL OF EVIDENCE

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

The ligamentum teres-its increasing importance

The ligamentum teres (LT) has attracted much greater interest over recent years due to the increased use of hip arthroscopy. There have been advancements in our understanding of the LT's biomechanical function and its role in hip and groin pain. Our ability to suspect LT tears by clinical examination and imaging has improved. Publications by many authors concerning LT tear treatment and outcomes continue to increase. This manuscript is a review of the function, mechanism of injury, clinical assessment, imaging, arthroscopic assessment, treatment, outcomes, reconstruction, and unusual conditions of the LT.

High affinity recognition of a Phytophthora protein by Arabidopsis via an RGD motif

The RGD tripeptide sequence, a cell adhesion motif present in several extracellular matrix proteins of mammalians, is involved in numerous plant processes. In plant-pathogen interactions, the RGD motif is believed to reduce plant defence responses by disrupting adhesions between the cell wall and plasma membrane. Photoaffinity cross-linking of [125I]-azido-RGD heptapeptide in the presence of purified plasma membrane vesicles of Arabidopsis thaliana led to label incorporation into a single protein with an apparent molecular mass of 80 kDa. Incorporation could be prevented by excess RGD peptides, but also by the IPI-O protein, an RGD-containing protein secreted by the oomycete plant pathogen Phytophthora infestans. Hydrophobic cluster analysis revealed that the RGD motif of IPI-O (positions 53-56) is readily accessible for interactions. Single amino acid mutations in the RGD motif in IPI-O (of Asp56 into Glu or Ala) resulted in the loss of protection of the 80-kDa protein from labelling. Thus, the interaction between the two proteins is mediated through RGD recognition and the 80-kDa RGD-binding protein has the characteristics of a receptor for IPI-O. The IPI-O protein also disrupted cell wall-plasma membrane adhesions in plasmolysed A. thaliana cells, whereas IPI-O proteins mutated in the RGD motif (D56A and D56E) did not.