Injury to the ligamentum teres. Mechanism, findings, and results of treatment

A guide to facilitate the creation of a femoral tunnel for arthroscopic ligamentum teres reconstruction: a three-dimensional computed tomography study

The ideal femoral tunnel passing through the centre of the femoral neck targeted to the footprint of the ligamentum teres (LT) is established during the LT reconstruction surgery with the free-hand technique. We aimed to quantitatively determine the entry site and define the angular orientation of the ideal femoral tunnel with its relevance to the femoral valgus angle (FVA) and the femoral anteversion angle (FAA) to facilitate the creation of an ideal femoral tunnel during the LT reconstruction surgery. A total of 60 randomly selected CT images were obtained to reconstruct three-dimensional femur models. A virtual reamer representing the ideal femoral tunnel was placed in the femur models. The femur length, FVA, FAA, the femoral tunnel anterior angle, the femoral tunnel superior angle and the skin- and bony-entry sites were measured. The femoral tunnel angular orientation was strongly correlated with the FVA and the FAA. Mathematical formulas were defined by which entry site of the reamer and the anterior and superior angulation of the femoral tunnel could be estimated before the surgery. The mean skin-entry site was 67.3 mm distal and 0.1 mm anterior to the centre of the greater trochanter's superior border. The angular orientation of the femoral tunnel using FVA and FAA can be easily estimated using mathematical formulas before LT reconstruction surgery. The entry site and angular orientation of the femoral tunnel described in this study can be used to reduce dependency on the usage of fluoroscopy and the workload on the surgeon during the LT reconstruction surgery.

Hip Dislocation and Subluxation in Athletes: A Systematic Review

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

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

RESULTS

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

CONCLUSION

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

Understanding hip pathology in ballet dancers

PURPOSE

The literature on hip injuries in ballet dancers was systematically evaluated to answer (1) whether the prevalence of morphological abnormalities and pathology of hip injuries in dancers differs from the general population (2) if there are any specific risk factors which contribute to a higher rate of hip injury and (3) what are the outcomes of primary and secondary intervention strategies.

METHODS

A systematic literature search of Medline, EMBASE and the Cochrane Library was undertaken for all literature relating to hip injuries in ballet dancers using the PRISMA guidelines. Reference lists were also searched for relevant literature. Clinical outcome studies, prospective/retrospective case series published between 1989 and October 2021 were included. Review articles (non-original data), case reports, studies on animals as well as book chapters were excluded.

RESULTS

The search yielded 445 studies, of which 35 were included for final analyses after screening. This included 1655 participants, of which 1131 were females. The analyses revealed that damage at the chondrolabral junction and degenerative disease of the hip may develop at a higher rate in ballet dancers than in the general population (odds ratio > 1 in 15/18 cohorts). The intra-articular lesions were more frequently found in postero-superior region of the hip suggesting an alternative impingement mechanism. Furthermore, numerous risk factors specific for hip injury in ballet were highlighted amidst a wide body of literature which consistently reports risk factors for a more generic 'dancer vulnerability'.

CONCLUSION

Ballet dancers may suffer from both higher rates of chondrolabral damage and degenerative disease in their hips. In contrast to other sports, the intra-articular lesions are more frequently found in postero-superior region of the hip. Future research clarifying the prevalence of osseous abnormalities and prevention strategies in dancers may be pivotal in delaying the development of hip disease in this cohort.

LEVEL OF EVIDENCE

Level IV.

The role and clinical relevance of the ligamentum teres: long-term outcomes after hip arthroscopic surgery of cam-type femoroacetabular impingement

We aimed to compare clinical and radiologic outcomes in patients with cam-type femoroacetabular impingement (FAI), with and without a partial ligamentum teres (LT) tear, who underwent hip arthroscopy (HA) with ≥10 years of follow-up. Among the patients who underwent HA for a cam-type FAI diagnosis with a labral tear, 28 patients (28 hips) with a partial LT tear and 87 patients (99 hips) with an intact LT were assigned to Groups A and B, respectively. All patients underwent partial labral debridement and femoroplasty. Debridement and thermal shrinkage were performed for LT tears. The grade of chondral damage was measured intraoperatively. Clinical items were assessed preoperatively and at the last follow-up. Patients’ satisfaction with the surgery and changes in postoperative sports ability in those who had previously been active in sports were assessed at the last follow-up. The Tönnis grade was assessed preoperatively and at the last follow-up for radiologic evaluation. Chondral damage to the acetabular and femoral head detected intraoperatively was significantly different between the groups (P = 0.005 and P &lt; 0.001). At the last follow-up, Group A patients experienced more difficulty performing sports activities than Group B patients (P = 0.056), and significantly, more Group A patients had stopped exercising despite their active participation in sports preoperatively (P = 0.002). Regarding the Tönnis grade, significant differences were found only at the final follow-up (P = 0.020). Patients with partial LT tear showed a higher grade of chondral damage, experienced decreased exercise capacity and had significantly worsened Tönnis grades, suggesting hip osteoarthritis progression compared to those with an intact LT.

Hip Pain: Imaging of Intra-articular and Extra-articular Causes

Hip pain is a common and complex clinical entity. The causes of hip injuries in athletes are many and diverse, requiring efficient, accurate diagnosis for proper management. Imaging is an important step in the clinical evaluation of hip pain, and familiarity with multiple imaging modalities as well as characteristic imaging findings is a helpful tool for sports medicine clinicians. This article discusses imaging recommendations and gives imaging examples of common causes of intra-articular and extra-articular hip pain including femoroacetabular impingement, labral tears, cartilage defects, ligamentum teres injuries, snapping hip syndrome, femoral stress injuries, thigh splints, athletic pubalgia, avulsion injuries, and hip dislocation.

[Direct MR Arthrography of the Hip: Diagnosis and Pitfalls of Acetabular Labral Lesions]

Tearing of the acetabular labrum is a common cause of chronic hip pain. MR arthrography (MRA) of the hip is the imaging procedure of choice for the evaluation of acetabular labrum. Familiarity with the various imaging findings of MRA of the hip allows recognition of normal variants and differentiation from true pathologic conditions. This article comprehensively reviews the technical aspects and interpretation of MRA of the hip. The appearances of normal and abnormal labra in MRA are discussed. Potential pitfalls in labral tear interpretation, such as sulci around the hip, normal variants of the labrum and plicae, and osseocartilaginous and soft tissue lesions identified on MRA of the hip are also described.

Load-deformation properties of the ligament of the head of femur in situ

The ligament of the head of femur (LHF) or ligamentum teres has been reported to tense during hip adduction and also to provide mechanical stability to the joint. LHF injury is more common in females and also in right hip joints compared with left ones. Although this could be due to leg dominance, pelvic size or muscle strength, there is no study that has looked into these differences. This cadaveric biomechanical study aimed to compare potential differences in the mechanical behavior of the LHF between neutral and 20° adducted hip joints, sex, and sides. Tensile tests of the LHF were performed on 25 hip joints (mean age at death of 85.7 ± 7.5 years; 9 females, 4 males; 13 left, 12 right), positioned either neutrally or in adduction. The maximum force required to rupture the ligament, its strain at failure, tensile strength, linear stiffness, and elastic modulus were obtained and statistically compared between analysis groups. The maximum force the LHF could withstand before rupture averaged 57 ± 37 N, strain at failure of 59 ± 33%, tensile strength of 2.9 ± 1.8 MPa, linear stiffness of 5.4 ± 3.5 N/mm, and elastic modulus of 7.2 ± 3.8 MPa. The LHF length at failure was significantly greater in males compared with females (P = 0.02). Irrespective of joint position, there were no statistical differences in the stress-strain properties of the LHF between females and males, or sides. There may be other anatomical, functional, and demographic factors that could render the ligament tissue vulnerable to injury in these groups. Clin. Anat., 33:705-713, 2020. © 2019 Wiley Periodicals, Inc.

The outcome of arthroscopic repair of acetabular labral tears using the iHOT-33

Background

The purpose of this study was to determine patient reported outcome measures (PROMS) after arthroscopic repair of an isolated labral tear using the validated International Hip Outcome Tool (iHOT-33). The iHOT-33 specifically measures (1) symptoms and functional limitations, (2) sport and recreation limitations, (3) job related concerns and social and (4) emotional and lifestyle concerns.

Methods

A retrospective review was performed on 45 procedures in 43 patients between September 2012 and September 2015. Two patients had bilateral isolated labral tears. Patients were excluded if they were younger than 18 years, had prior ipsilateral hip surgery and had radiological or arthroscopic evidence of femoroacetabular impingement (FAI), hip dysplasia or other bony dysmorphism.

Results

Of the 43 patients undergoing arthroscopy there were 29 right and 16 left hips repaired. There were 34 females and 9 males. The mean age at surgery was 37.4 years (range 19–63 years) with a mean follow up of 1.7 years (range 1.0–2.6 years). At follow up the mean total iHOT-33 score improved from 34.1 to 67.3 (p < 0.02). The mean improvement was 33.2 (p = < 0.02). Significant improvements were described in all 4 iHOT-33 sub sections.

Conclusion

The study showed statistically significant favourable outcomes in selected patients with short follow-up for patients that underwent hip arthroscopy for an isolated labral tear using the validated iHOT-33.

Level of Evidence

IV, retrospective non-randomised study.

Non-traumatic ligamentum teres tears: association with MRI morphometry of the hip

BACKGROUND

The ligamentum teres has been recognized as an important stabilizer of the hip.

PURPOSE

We aimed to examine the relationship between non-traumatic ligamentum teres (LT) tear and hip morphometry on magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Fifty patients who had undergone hip MRI were included (27 men, 23 women; average age = 54.0 years). The status of the LT and the morphometric hip parameters were assessed, including acetabular anteversion angle (AAA), acetabular depth (AD), acetabular index (AI), lateral center edge angle (LCEA), and extrusion index (EI). The morphometric hip parameters were compared between groups with one-way ANOVA, Student's t-test, and Mann-Whitney U test.

RESULTS

A decreased acetabular coverage was noted in the severe tear group compared to the normal group, indicated by a significantly larger AD ( P = 0.001) and smaller LCEA ( P = 0.016). There was a statistically significant difference in the AAA, AD, and LCEA between the normal group and the complete tear group; the AAA was significantly larger ( P = 0.031), the AD was significantly larger ( P = 0.01), and the LCEA was significantly smaller ( P = 0.043) in the complete tear group compared to the normal group.

CONCLUSION

There is an association between LT tears and acetabular bony morphology; an insufficient acetabular coverage is associated with complete tear of the LT. As the insufficient acetabular coverage may predispose to ligamentum teres tear, the ligamentum teres should be thoroughly evaluated in those with insufficient acetabular coverage, as a potential cause of hip pain.

Neurovascular structures of the ligament of the head of femur

The ligament of the head of femur (LHF), or ligamentum teres, is believed to provide blood supply to the head of femur and mechanical stability to the hip joint. But these functions in the adult are often debated. The existence and distribution of neurovascular structures within the ligament are not widely documented. This study examined the blood vessels and nervous tissue within the LHF to determine whether the ligament may have a vascular and proprioceptive function at the hip joint. Histological sections from the LHF from 10 embalmed hips (six female, four male; mean age 80.4 ± 8.7 years) were cut at three levels: the foveal attachment, mid-length and its base where it attaches to the transverse acetabular ligament. Sections were stained with haematoxylin and eosin to study general tissue architecture or with von Willebrand factor and neurofilament to identify blood vessels and nervous tissue, respectively. The proportion of the ligament's cross-sectional area occupied by blood vessels was expressed as a vascularity index (VI). Nerve endings within the ligament were identified and morphologically classified. Comparisons between the VI at the three levels, or between the tissue layers of the ligament, were made using 95% confidence intervals; statistical significance was set P < 0.05. The ligament tissue comprised three distinct layers: a synovial lining with cuboidal cells, a sub-synovial zone formed of loose connective tissue and the ligament proper composed of dense collagen bundles. Patent blood vessels and nerve fibres were present both in the sub-synovial zone and the ligament proper; Pacinian corpuscles and free nerve endings were found scattered only in the sub-synovial zone. The VI of the ligament proper at the fovea was significantly higher than its middle (P = 0.01) and basal levels (P = 0.04); it was also higher than that of the sub-synovial layer (P = 0.04). The LHF has three histologically distinct zones, and blood vessels and nerves are distributed both in the sub-synovial layer and ligament proper. Higher vascularity within the ligament proper at its foveal insertion suggests a possible nutritive role of the LHF to the adult head of femur. The presence of nerves and nerve receptors indicates the ligament is involved in the perception of pain and proprioception, thereby contributing to mechanical stability of the joint.

The Expanding Role of Hip Arthroscopy in Modern Day Practice

Over the past decade, hip arthroscopy has become increasingly popular in managing hip conditions in a minimally invasive approach. The development of specialist equipment and training in this field has allowed indications for hip arthroscopy to be extended to a range of conditions. However, the need for special equipment and training has also limited the use of hip arthroscopy to specialized centers. This article will outline the evolution of hip arthroscopy, the pathology of hip conditions, what it has been used for and how this technique has now been extended to help manage these conditions in a minimally invasive approach, limiting the complications of open surgery.

The ligamentum teres femoris in orangutans

OBJECTIVES

It is widely viewed that orangutans lack a ligamentum teres femoris (LTF) inserting on the femoral head because orangutans lack a distinct fovea capitis. Orangutans employ acrobatic quadrumanous clambering that requires a high level of hip joint mobility, and the absence of an LTF is believed to be an adaptation to increase hip mobility. However, there are conflicting reports in the literature about whether there may be a different LTF configuration in orangutans, perhaps with a ligament inserting on the femoral neck instead. Here we perform a dissection-based study of orangutan hip joints, assess the soft tissue and hard tissue correlates of the orangutan LTF, and histologically examination the LTF to evaluate whether it is homologous to that found in other hominoids.

MATERIALS AND METHODS

The hip joints from six orangutans were dissected. In the two orangutans with an LTF passing to the femoral head, the LTF was assessed histologically. Skeletonized femora (n=56) in osteological repositories were examined for evidence of a foveal pit.

RESULTS

We observed an LTF in two of the three infant orangutans but not in the sub-adult or adult specimens. Histological examination of the infant LTF shows a distinct artery coursing through the LTF to the head of the femur. One percent of orangutan femora present with a foveal scar, but no pit, on the femoral head.

DISCUSSION

Despite being absent in adults, the LTF is present in at least some orangutans during infancy. We suggest that the LTF maintains a role in blood supply to the femoral head early in life. Because the LTF can limit hip mobility, this may explain why the LTF may be lost as an orangutan ages and gains locomotor independence. These findings enhance our understanding of orangutan hip morphology and underscore the need for future soft tissue investigations.

Posterior Bony Impingement-Potential Mechanism of Ligamentum Teres Tears

PURPOSE

To describe a potential causal mechanism of ligamentum teres (LT) tears, a specific treatment for posterior impingement of the LT, and to report the minimum 2-year outcome of this treatment.

METHODS

We retrospectively reviewed data collected from 1,251 hip arthroscopies performed by the senior surgeon over a 26-month period. During this time, 424 LT tears were identified including 9 patients with isolated partial LT tears caused by impingement of the LT against a prominent acetabular fossa posterior wall and no other intra-articular pathology. All 9 patients were treated with LT tear debridement and excision of the impinging bony prominence using an arthroscopic burr. Patients were followed with a modified Harris hip score and nonarthritic hip score for a minimum of 24 months (mean, 29 months; range, 24-38 months).

RESULTS

After surgery, all patients returned to their preinjury level of activity. The modified Harris hip score increased from a mean of 58.9 preoperatively (range, 41.8-84.7) to 89.2 (range, 70.3.5-96.7) (P = .02) at a minimum of 2-year follow-up. Similarly, the nonarthritic hip score increased from a mean of 56.2 (range, 35-90) to 91.9 (range, 81.5-98.5) (P = .01) at a minimum of 2 years after surgery. There were no complications associated with the procedure and no revision surgeries performed over the 2-year follow-up.

CONCLUSIONS

LT tears may, very uncommonly, be caused by impingement of the mid-part of the ligament against a prominent posterior acetabular fossa edge. In this group of 9 cases, debridement of the torn ligament segment, in combination with resection of the impinging bone, was associated with marked symptomatic improvement and full return to activities for a minimum of 2 years.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Contribution of the Ligamentum Teres to Hip Stability in the Presence of an Intact Capsule: A Cadaveric Study

PURPOSE

To determine the contribution of the ligamentum teres (LT) to hip stability in the presence of an intact capsule with special attention to the change in range of motion and femoral head translation.

METHODS

Seven fresh-frozen cadaveric pelvises were used. Following visual inspection of the LT at different hip positions, internal rotation angles were measured at 10° of extension and at 0° of flexion, while external rotation was measured at 60°, 90°, and 110° of flexion with different hip abduction angles using electromagnetic motion tracking sensor. Femoral head translations were measured simultaneously. The tests were repeated after resection of the LT. The capsule was left intact for all test conditions. The results were compared between intact and LT resected conditions when torque of 2 and 4 Nm was applied.

RESULTS

Compared with the intact hip, the LT resected hip showed no significant difference when 2 Nm torque was applied in all scenarios. With 4 Nm torque application, significant increase in external rotation was found at 60° and at 90° of flexion (1.7° ± 0.8° and 2.1° ± 1.0°, respectively). Significant difference was also noted at 60°, 90°, and 110° of flexion when the hip was in the adducted position while at 90° in the abducted hip. However, LT resection did not show significant change in internal rotation. There was no significant difference in the translation distance of the femoral head in the intact hip compared with the LT resected hip (0.77-1.11 mm vs 0.79-1.29 mm).

CONCLUSIONS

Our results indicate that within the physiologic range of motion, LT can minimally limit external rotation when the hip is in the flexed position but does not contribute to translation stability.

CLINICAL RELEVANCE

In the hip with intact capsule, LT deficiency can result in a slight increase in range of motion, but its contribution to stability is questionable.

Osseous spurs at the fovea capitis femoris-a frequent finding in asymptomatic volunteers

OBJECTIVE

To investigate the different morphologic types of the fovea capitis femoris and the spectrum of osseous spurs/osteophytes of the fovea in asymptomatic volunteers and patients with hip osteoarthritis.

MATERIAL AND METHODS

Sixty-five patients (mean age 63.6 years) with radiographically confirmed osteoarthritis of the hip and 59 asymptomatic healthy volunteers (mean age 33.9 years) underwent non-contrast MRI of the hip joint. Two radiologists independently evaluated all images. Fovea morphology (standard type, diamond type, flat type, triangular type) as well as the frequency, size and location of spurs/osteophytes of the fovea were assessed. Descriptive and inferential statistics were applied.

RESULTS

The most frequent morphologic type of the fovea capitis femoris was the standard type for both asymptomatic volunteers (average 45%) and patients (average 49%). Osseous spurs were detected in 70% of the asymptomatic volunteers, and 97% of the patients had osteophytes. Spur size at all locations was significantly smaller in asymptomatic volunteers (range 1-2 mm) than osteophyte size in patients (range 1-4 mm) (p ≤ 0.035). In volunteers and patients, the spurs/osteophytes were most frequently located at the anterior border of the fovea capitis femoris.

CONCLUSION

Smaller osseous spurs (<2 mm) at the border of the fovea capitis femoris are very common in asymptomatic volunteers and do not seem to be pathologic.

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.

Sports Injuries about the Hip: What the Radiologist Should Know

Injuries of the hip and surrounding structures represent a complex and commonly encountered scenario in athletes, with improper diagnosis serving as a cause of delayed return to play or progression to a more serious injury. As such, radiologists play an essential role in guiding management of athletic injuries. Familiarity with hip anatomy and the advantages and limitations of various imaging modalities is of paramount importance for accurate and timely diagnosis. Magnetic resonance (MR) imaging is often the modality of choice for evaluating many of the injuries discussed, although preliminary evaluation with conventional radiography and use of other imaging modalities such as ultrasonography (US), computed tomography, and bone scintigraphy may be supplementary or preferred in certain situations. Stress fractures, thigh splints, and posterior hip dislocations are important structural injuries to consider in the athlete, initially imaged with radiographs and often best diagnosed with MR imaging. Apophyseal injuries are particularly important to consider in young athletes and may be acute or related to chronic repetitive microtrauma. Femoroacetabular impingement has been implicated in development of labral tears and cartilage abnormalities. Tear of the ligamentum teres is now recognized as a potential cause of hip pain and instability, best evaluated with MR arthrography. Greater trochanteric pain syndrome encompasses a group of conditions leading to lateral hip pain, with US playing an increasingly important role for both evaluation and image-guided treatment. Muscle injuries and athletic pubalgia are common in athletes. Lastly, snapping hip syndrome and Morel-Lavallée lesions are two less common but nonetheless important considerations. ^©RSNA, 2016.

The reliability of commonly used arthroscopic classifications of ligamentum teres pathology

The importance of the ligamentum teres (LT) in the hip is increasingly being recognized. However, the incidence of LT tears in the literature is extremely variable. Although classification systems exist their reliability in classifying LT pathology arthroscopically has not been well defined. To determine the inter- and intra-observer reliability of two existing classifications systems for the diagnosis of LT pathology at hip arthroscopy. Second, to identify key pathological findings currently not included. Four experienced hip-arthroscopists reviewed 40 standardized arthroscopic videos. Arthroscopic findings of the LT were classified using the Gray and Villar (G&V) and descriptive classification (DC). Reviewers were asked to record other relevant pathology encountered. Inter- and intra-observer reliability was defined using Fleiss-Kappa and Cohen-Kappa statistics. Both classifications demonstrated fair inter-observer reliability. The intra-observer reliability for G&V was moderate-to-substantial and for DC was slight-to-moderate. An absolute agreement rate of 10% (G&V) and 37.5% (DC) was found. Differentiation between normal, and partial or low-grade tears was a common source of disagreement. The prevalence of LT pathology was 90%. Synovitis was the most common diagnostic finding that was not included in either classification system used in this study. Arthroscopic classification of LT pathology using the G&V and the DC demonstrated only fair inter-observer reliability. The major discrepancy in interpretation was between normal, and partial or low-grade tears. The presence of synovitis was not in either classification but was considered an important arthroscopic finding. Thorough arthroscopic scrutiny reveals the prevalence of LT pathology is higher than previously reported.

Quantitative Anatomic Analysis of the Native Ligamentum Teres

Background:

While recent studies have addressed the biomechanical function of the ligamentum teres and provided descriptions of ligamentum teres reconstruction techniques, its detailed quantitative anatomy remains relatively undocumented. Moreover, there is a lack of consensus in the literature regarding the number and morphology of the acetabular attachments of the ligamentum teres.

Purpose:

To provide a clinically relevant quantitative anatomic description of the native human ligamentum teres.

Study Design:

Descriptive laboratory study.

Methods:

Ten human cadaveric hemipelvises, complete with femurs (mean age, 59.6 years; range, 47-65 years), were dissected free of all extra-articular soft tissues to isolate the ligamentum teres and its attachments. A coordinate measuring device was used to quantify the attachment areas and their relationships to pertinent open and arthroscopic landmarks on both the acetabulum and the femur. The clock face reference system was utilized to describe acetabular anatomy, and all anatomic relationships were described using the mean and 95% confidence intervals.

Results:

There were 6 distinct attachments to the acetabulum and 1 to the femur. The areas of the acetabular and femoral attachment footprints of the ligamentum teres were 434 mm² (95% CI, 320-549 mm²) and 84 mm² (95% CI, 65-104 mm²), respectively. The 6 acetabular clock face locations were as follows: anterior attachment, 4:53 o’clock (95% CI, 4:45-5:02); posterior attachment, 6:33 o’clock (95% CI, 6:23-6:43); ischial attachment, 8:07 o’clock (95% CI, 7:47-8:26); iliac attachment, 1:49 o’clock (95% CI, 1:04-2:34); and a smaller pubic attachment that was located at 3:50 o’clock (95% CI, 3:41-4:00). The ischial attachment possessed the largest cross-sectional attachment area (127.3 mm²; 95% CI, 103.0-151.7 mm²) of all the acetabular attachments of the ligamentum teres.

Conclusion:

The most important finding of this study was that the human ligamentum teres had 6 distinct points of attachment on the acetabulum (transverse, anterior, and posterior margins of the acetabular notch and cotyloid fossa attachments: ilium, ischium, and pubis) and 1 on the femur. On the acetabulum, the anterior attachment was substantially larger than the posterior attachment and was located at a mean clock face position of 4:53 o’clock.

Clinical Relevance:

These quantitative descriptions of the ligamentum teres can be used by clinicians to arthroscopically identify the attachments of the ligamentum teres, guiding arthroscopic surgical interventions designed to address ligamentum teres pathology.

Hip arthroscopy complications regarding surgery and early postoperative care: retrospective study and review of literature

PURPOSE

The purpose is to describe the rate of complications in a series of hip arthroscopies performed at our center, as well as perform a systematic review of the current literature in order to compare our outcomes.

METHODS

Two hundred and fifty-eight patients affected of femoroacetabular impingement and treated with hip arthroscopy have been studied. All minor and major complications were studied during the first postsurgery year. Furthermore, a systematic review was performed comparing major and minor complications with our series. Two attending orthopedic surgeons selected the different studies with the same inclusion and exclusion criteria, remaining with 48 studies that have been reviewed and included in the present study.

RESULTS

Mean age was 36.6 years old (SD 17.45), and the ratio men:women was 137:121. The mean complication rate observed was 14.34% (37/258) of global complications. Only three patients showed major complications: femoral neck fracture, septic arthritis and avascular necrosis of the femoral head. Any of these patients had permanent side effects.

CONCLUSIONS

Hip arthroscopy has a low rate of major complications, but a higher number of minor complications that could be avoided with certain preventive measures.

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 ligamentum capitis femoris: anatomic, magnetic resonance and computed tomography study

The objective of the study was to describe the normal anatomy of the ligamentum capitis femoris and to determine the neurovascular structures potentially at risk during its reconstruction. Ten cadaveric specimens of the ligamentum capitis femoris (LCF) were dissected and photographed. Magnetic resonance (MR) and Computed tomography (CT) arthrography evaluation of the anatomy of the LCF in 30 hips were performed to measure length of the ligament and to study the proximity of neurovascular structures. The anatomical study showed that the LCF has a pyramidal structure and a banded appearance. The thickness of the medial wall of the acetabulum 3 mm superior to the inferior acetabular boundary was found to be 6.7 mm (4-9 mm) at point 1 (anterior), 4.1 mm (3-7 mm) at point 2 (central), and 6.5 mm (4-9 mm) at point 3 (posterior). Central anchors or screws were found to lie within 1.7 cm (1.6-1.9 cm) of the external iliac vein and artery. Angulation of anchors in the anterior and posterior columns in the axial plane with respect to acetabular fossa floor (the Optimal Angulation Angle or OAA), is safer (0 to 45º the safest optimal angles). The sagittal angulation created by the safe pathway in the anterior and posterior columns with respect to the plane of the facies lunata in this area was also measured and termed the Optimal Angle of Penetration (OAP) with normal values being: 110º (102-123º) for the posterior column and 90º (85-94º) for the anterior column. Our results suggest that reconstruction of the LCF can be safely performed if these guidelines are followed.

Arthroscopic Treatment of Traumatic Hip Dislocation

Traumatic hip dislocations are high-energy injuries that often result in considerable morbidity. Although appropriate management improves outcomes, associated hip pathology may complicate the recovery and lead to future disability and pain. Historically, open reduction has been the standard of care for treating hip dislocations that require surgical intervention. The use of hip arthroscopy to treat the sequelae and symptoms resulting from traumatic hip dislocations recently has increased, however. When used appropriately, hip arthroscopy is a safe, effective, and minimally invasive treatment option for intra-articular pathology secondary to traumatic hip dislocation.

Hip arthroscopy

Hip arthroscopy is a safe method for treating a variety of pathological conditions that were unknown until a decade ago. Femoroacetabular impingement is the commonest of these pathological conditions and the one with the best results when treated early on. The instruments and surgical technique for hip arthroscopy continue to evolve. New indications for hip arthroscopy has been studied as the ligamentum teres injuries, capsular repair in instabilities, dissection of the sciatic nerve and repair of gluteal muscles tears (injuries to the hip rotator cuff), although still with debatable reproducibility. The complication rate is low, and ever-better results with fewer complications should be expected with the progression of the learning curve.

Groin pain in athletes: a novel diagnostic approach

Groin pain in a performing athlete can be very challenging to diagnose and treat. The differential diagnosis includes intra-articular causes, extra-articular causes and non-musculoskeletal causes. A detailed clinical and radiological assessment of groin pain in this group is critical and can identify the underlying pathology. Diagnostic hip block is a valuable tool to differentiate intra-articular causes from extra-articular causes. Hip arthroscopy can help in identifying some of the elusive intra-articular conditions, which were once undiagnosed and therefore, left untreated, resulting in premature ending of competitive careers. This article attempts to explore current thinking on evaluation of groin pain, particularly in young individuals, and to establish a simple protocol for a clinical and diagnostic approach to this difficult problem.

Ligamentum teres injuries - an observational study of a proposed new arthroscopic classification

Ligamentum teres (LT) Injuries or tears have been said to be a common cause of groin discomfort and pain, and they have been identified in 8–51% of patients undergoing hip arthroscopy. Currently, in the literature there exist three arthroscopic classifications for LT injuries and tears: the first classification was established by Gray and Villar, Botser and Domb proposed the second one which they called a descriptive classification according to the degree of partial thickness LT tears and more recently the last classification by Cerezal et al. (RadioGraphics 2010; 30:1637–51), where they take into account the one by Gray and Villar but adding an avulsion fracture and absence of the LT. We propose a new classification, which also takes into account, observed LT pathologies, as well as the possible pathological mechanism of LT tears, and offer a guide to treatment. This classification is based on direct arthroscopic observation and dynamic rotational maneuvers of the hip under distraction. This classification incorporates those pathologies, which have been observed as a result of this more focused examination of the LT.

Understanding the ligamentum teres of the hip: a histological study

OBJECTIVE

To perform a histological study describing the microstructure of the ligamentum teres of the hip, with special emphasis on the presence of nerve bundles. Our study aims to correlate the microstructure of the ligamentum teres with its postulated functions, allowing greater understanding of its role within the hip joint.

METHODS

Fresh specimens excised intra-operatively in 11 patients undergoing open hip procedures were preserved in formalin and sent to the laboratory for histological analysis by our collaborating pathologist. The specimens were sectioned and stained, and examined under the microscope to look at their microstructure. In addition, a novel staining technique was employed to detect neural elements within the individual specimens .

RESULTS

The ligamentum teres is composed predominantly of a connective tissue matrix of collagen fibers, fibrous and adipose tissue, with an overlying layer of investing synovium. In addition, there are blood vessels of various sizes surrounded by a layer of encircling fat. In all specimens examined, there were nerve bundles of various shapes and sizes, regardless of the age of the patient.

CONCLUSION

The ligamentum teres has both mechanical and biological functions within the hip joint and should no longer be considered a developmental vestige. Where possible, any surgical procedures around the hip joint should aim to limit damage to this structure to minimize any potential loss of function. Level of Evidence Basic Science Study.

Comparison of mechanoreceptor quantities in hip joints of developmental dysplasia of the hip patients with normal hips

BACKGROUND

Joint mechanoreceptors are afferent neural elements involved in pain sensation and tactile sense.

QUESTIONS/PURPOSES

We aimed to detect the free nerve endings (FNE) and other types of mechanoreceptors and to compare their quantities in human hip joint capsule (HJC) and ligamentum capitis femoris (LCF) of babies with developmantal dysplasia of hip (DDH) and intrauterine ex foetuses (control group) to find out whether there is an increase in the amount of mechanoreceptors in hip joint due to the occured anatomical chages.

PATIENTS AND METHODS

We took 15 LCF and HJC biopsies from 15 patients undergoing hip surgery for DDH, and 15 HJC and LCFs from intrauterine ex fetuses. Total of 60 specimens were investigated. The mean age of the babies was 10.3 months (6-18 months) at the time of surgery. Full thickness 1 × 1 cm HJC and LCF portions were taken as biopsy specimens. An immunohistochemical technique was performed for neurogenic protein S-100 and examined under light microscopy.

RESULTS

FNEs were detected in all four different tissues (type IVa). Other types of mechanoreceptors (Type I-II and III) were not detected in any of the specimens. The positive rates of FNE staining in the control group were % 2.60 ± 1.24 for the LCF and % 2.67 ± 1.11 for the HJC respectively and FNE staining in the DDH group were found to be % 2.67 ± 1.11 for the LCF and % 2.73 ± 1.16 for the HJC. We did not find a statistically significant difference in number of FNEs between the specimens of the DDH group and the control group (p>0.05), also there was no statistically significant difference in number of FNEs between the HJC and LCF within each group (p>0.05).

CONCLUSION

Our results suggest that the number of FNEs does not increase in HJC and LCF of DDH patients even though LCF hypertrophy and capsular elongation occurs.

Structural Properties of the Native Ligamentum Teres

Background:

A majority of studies investigating the role of the ligamentum teres (LT) have focused primarily on anatomical and histological descriptions. To date, however, the structural properties of the LT have yet to be fully elucidated.

Purpose:

To investigate the structural properties of the native LT in a human cadaveric model.

Study Design:

Descriptive laboratory study.

Methods:

A total of 12 human cadaveric hemipelvises (mean age, 53.6 years; range, 34-63 years) were dissected free of all extra-articular soft tissues to isolate the LT and its acetabular and femoral attachments. A dynamic tensile testing machine distracted each femur in line with the fibers of the LT at a displacement-controlled rate of 0.5 mm/s. The anatomic dimensions, structural properties, and modes of failure were recorded.

Results:

The LT achieved a mean yield load of 75 N and ultimate failure load of 204 N. The LT had mean lengths of 38.0 and 53.0 mm at its yield and failure points, respectively. The most common (75% of specimens) mechanism of failure was tearing at the fovea capitis. On average, the LT had a linear stiffness of 16 N/mm and elastic modulus of 9.24 MPa. The mean initial length and cross-sectional area were 32 mm and 59 mm², respectively.

Conclusion:

The human LT had a mean ultimate failure load of 204 N. Therefore, the results of this investigation, combined with recent biomechanical and outcomes studies, suggest that special consideration should be given to preserving the structural and corresponding biomechanical integrity of the LT during surgical intervention.

Clinical Relevance:

The LT may be more important as a static stabilizer of the hip joint than previously recognized. Further studies are recommended to investigate the appropriate indications to perform surgical repair or reconstruction of the LT for preservation of hip stability and function.

Nonarthritic hip joint pain

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). The purpose of these clinical practice guidelines is to describe the peer-reviewed literature and make recommendations related to nonarthritic hip joint pain.

Preoperative diagnosis of pathologic conditions of the ligamentum teres: is MRI a valuable imaging modality?

PURPOSE

The purpose of this study was to determine the accuracy of 3-Tesla magnetic resonance imaging (MRI) in detecting ligamentum teres (LT) lesions in patients before they undergo hip arthroscopy for the treatment of femoroacetabular impingement.

METHODS

From 2010 to 2011, data were prospectively collected on all patients presenting for treatment of hip pain. All patients underwent MRI followed by arthroscopic surgery. A radiologist prospectively documented MRI findings, and the surgeon recorded the findings at arthroscopy. Radiologic and surgical data included classification of the LT as not torn, hypertrophic, partially torn, or completely torn. All MR images were read by a single radiologist, and all surgery was performed by a single surgeon. Arthroscopy was considered the diagnostic gold standard.

RESULTS

One hundred forty-two patients with a mean patient age of 35 years (range, 19 to 73 years) met the inclusion criteria. Only one complete LT tear was found in the study. The accuracy of MRI for the diagnosis of LT partial tears was 64%. The sensitivity and specificity of MRI for diagnosing partial tears of the LT were 9% and 91%, [corrected] respectively. The positive predictive value and negative predictive value were 31% and 67%, [corrected] respectively. The sensitivity and specificity of MRI for diagnosing hypertrophic LT were 32% and 78%, respectively.

CONCLUSIONS

In this patient population, MRI demonstrated sensitivity and specificity of 34% and 50%, [corrected] respectively, in identifying any pathologic process of the LT. MRI is capable of ruling out [corrected] partial tears of the LT with high sensitivity (91%) and negative [corrected] predictive value (67%).

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria on basis of consecutive patients with universally applied gold standard.

The ligamentum teres test: a novel and effective test in diagnosing tears of the ligamentum teres

BACKGROUND

A ligamentum teres (LT) injury is a common finding at the time of hip arthroscopic surgery in patients with chronic groin and hip pain; however, LT tears have been difficult to identify before surgery. There have been no unique features identified on history assessment, physical examination, or imaging that reliably identify injuries of the LT preoperatively.

PURPOSE

To report a new clinical examination to assess the presence of an LT tear: the LT test.

STUDY DESIGN

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

METHODS

The study consisted of 75 patients undergoing hip arthroscopic surgery for multiple lesions. Each patient was evaluated by 2 independent examiners using the LT test, leading to a total of 150 tests being performed. The LT test is conducted with the hip flexed at 70° and 30° short of full abduction; the hip is then internally and externally rotated to its limits of motion. Pain on either internal or external rotation is consistent with a positive LT test result. Hip arthroscopic surgery was then performed and all intra-articular abnormalities noted. Arthroscopic images were taken of each LT and examined by a third independent examiner who determined the presence or absence of a tear. Clinical examination findings were compared with the arthroscopic findings to determine the sensitivity, specificity, and positive and negative predictive values. In addition, the presence of intra-articular pathological lesions was compared with the test results to determine if there was a correlation between the presence of an intra-articular pathological abnormality and a positive LT test result.

RESULTS

Of the 150 examinations performed, the test result was positive 55% of the time (77 examinations). The sensitivity and specificity of the test were 90% and 85%, respectively. The positive predictive value was 84%, and the negative predictive value was 91%. The presence of an LT tear, pincer lesion, and labral tear that required repair was associated with a positive LT test result. The κ coefficient for interobserver reliability was .80.

CONCLUSION

The LT test is an effective way of assessing the presence of LT tears with moderate to high interobserver reliability. In addition to an LT tear, the presence of a pincer lesion or labral tear requiring repair are also associated with a positive LT test result.

Review of sport-induced groin injuries

CONTEXT

Groin injuries are among the most common injuries co-existing with sports. The aim of this review was to outline the epidemiology and identify risk factors, as well as examine preventative and interventional measures for reducing the occurrence of this form of injury among athletes.

EVIDENCE ACQUISITION

An electronic, systematic search for relevant keywords, either separately or in combination was sought in the academic scientific databases.

RESULTS

Groin injuries, acute or chronic, consist of a high percentage of injuries that manifest with pain. Despite the specific tendency for injury among some sports, such injuries make up 2-5% of sport-induced injuries. There are few available reports on lower limb injuries, especially groin injuries, in Iran. Numerous factors predispose to groin injuries. A lengthy list of preventive/ treatment measures, from preliminary to sophisticated, have been proposed.

CONCLUSIONS

Although using a programmed strategy designed to decrease the risk of groin injuries by taking a strategic approach to exercise may alleviate complications, in some cases the chronic nature of the injury may threaten the professional life of the athlete. More research is required to plan suitable programs for reducing the risk of this type of injury in athletes.

Emerging intra-articular causes of groin pain in athletes

Groin pain remains one of the most poorly understood conditions in clinical sports medicine. It may be caused by either extra-articular or intra-articular conditions. While extra-articular causes have been extensively studied and reasonably understood, a number of elusive intra-articular causes are emerging, many of which were previously unknown and therefore undiagnosed, leading to premature ending of many competitive careers. This article makes an attempt to look at various, elusive intra-articular causes of groin pain in athletes. This article also analyses the currently available evidence on trends in diagnosis and treatment for these conditions.

Function of the ligamentum teres during multi-planar movement of the hip joint

PURPOSE

The purpose of this study was to describe the orientation of the ligamentum teres and quantify the limb position when the ligamentum teres reached its endpoint during a simulated squat position in human cadavers.

METHODS

Dissection of eight (4 male; 4 female) cadavers resulted in the complete removal of all soft tissue attachment of the femur to the acetabulum, leaving only the ligamentum teres intact. The limb was then moved into combined flexion and abduction of the hip joint to simulate a deep squat position until a ligamentous endpoint of the ligamentum teres was achieved. The orientation of the ligamentum teres in relation to the femoral head was described and the position of the limb relative to the sagittal plane (flexion) and frontal plane (abduction) was quantified. The mean, standard deviation, 95 % confidence intervals, and standard error of the measurement were calculated for the observed angles.

RESULTS

Multi-planar movement of flexion and abduction moved the ligamentum teres into an anterior/inferior position relative to the femoral head and prevented the femoral head from anterior/inferior subluxation. The ligamentum teres endpoint was obtained at a combined average position of 100.6° (range 94°-112°; SD 5.5º; 95 % CI 96º-105º) and 20.0° (range 12°-32°; SD 7.0º; 95 % CI 14º-26º) flexion and abduction angle.

CONCLUSIONS

The ligamentum teres formed a "sling-like" structure to support the femoral head inferiorly as the hip joint was moved into a combined position of flexion and abduction that resembled a squat position. The results help to define a possible role of the ligamentum teres in hip joint stability and possible mechanisms of injury.

A cadaveric model for ligamentum teres function: a pilot study

PURPOSE

Despite the prevalence and clinical consequences of ligamentum teres pathology, its function is poorly understood. The purpose of this study was to help define the role the ligamentum teres may have in hip joint stabilization and determine whether a ball and string model could be used to describe the function of the ligamentum teres.

METHODS

Eight embalmed cadavers were dissected to remove all soft tissue from around the hip, leaving only the ligamentum teres intact. Available hip abduction, adduction, medial rotation, and lateral rotation range of motion were measured for three repeated trials. The position of the ligamentum teres in relation to the femoral head was recorded at the endpoint position of these movements.

RESULTS

An endpoint position as limited by the ligamentum teres for abduction, medial rotation, and lateral rotation was identified at a mean of 73°(SD 11°), 64°(SD 11°), and 58°(SD 10°), respectively. Hip adduction was limited by bony contact and therefore was not measured. The ligamentum teres wrapped around the femoral head to prevent inferior, posterior, and anterior subluxation with abduction, medial rotation, and lateral rotation, respectively. Repeated measures ANOVA indicated no significant difference in endpoint position based on trial number for the three movements (n.s.).

CONCLUSION

The ligamentum teres consistently tightened to limit hip abduction, medial rotation, and lateral rotation. These results support a ball and string model for the femoral head and ligamentum teres. This information could be important for those with hip instability and ligamentum teres pathology.

MR imaging of the hip: pathologies and morphologies of the hip joint, what the surgeon wants to know

MR imaging of the hip is frequently used in symptomatic patients before hip preservation surgery; it is used as a decision-making tool and as a planning tool. The MRI can confirm the preliminary working diagnosis, identify other possible sources of pain, and highlight anatomic areas that are not routinely viewed during surgery. In addition, MR imaging is capable of illustrating normal and abnormal bony morphology of the femur and pelvis; and in the case that arthrography is used, diagnostic injection can be administrated concurrently. This article highlights a surgeon's perspective on the use of MR imaging in the patient with nonarthritic hip pain.

Imaging appearance of the normal and partially torn ligamentum teres on hip MR arthrography

OBJECTIVE

The purpose of this study was to evaluate the MR arthrographic appearance of the normal and partially torn ligament teres and to determine if there are imaging criteria for diagnosing partial tears of the ligamentum teres.

MATERIALS AND METHODS

One hundred sixteen patients underwent preoperative MR arthrography and hip arthroscopy. Each MR examination was evaluated independently by two musculoskeletal radiologists for the following: size and width of the ligamentum teres in the proximal, mid, and distal thirds of the ligamentum teres; overall length of the ligamentum; number of bundles (1-3); signal intensity (SI) within the ligamentum teres (low, intermediate, high); ligamentum teres fibers (normal, attenuated, thickened, wavy); ligamentum teres integrity (not torn, degenerated, frayed, partial tear); and femoral head edema at the ligamentum teres origin. Statistical analysis was performed using the Kruskal-Wallis rank sum test and Fisher exact test.

RESULTS

Twelve of 116 (10%) subjects had partial ligamentum teres tears. One hundred four subjects had an intact ligamentum teres. The average size and width of the intact ligamentum teres was 12.6 × 4.38, 14.9 × 3.5, and 14.3 × 2.7 mm for proximal, mid, and distal, respectively, with an overall length 27.7 mm. It was most common to visualize two bundles in the proximal portion of the normal ligamentum teres (61 and 64/116). Low, intermediate, and high SI was common on all pulse sequences in normal and partially torn ligamentum teres for both readers (p = 0.33-0.84). For reader 1, there was no statistical difference between ligamentum teres fiber appearance in partial tears (p = 0.20). In contrast, reader 2 found partial tears associated with attenuated and wavy appearance (p = 0.003). Reader 1 diagnosed five of 12 (42%), and reader 2 diagnosed eight of 12 (67%) of the partial ligamentum teres tears (p = 0.47 and p = 0.0004). Edema of the femoral ligamentum teres origin was not associated with partial tears (p = 0.33-0.86). Retrospective review revealed that six partial tears had intra substance linear high SI on T2 images and peripheral irregularity, whereas four other tears had high SI within the ligamentum teres fibers without peripheral irregularity.

CONCLUSION

The intact and partially torn ligamentum teres can have similar imaging findings on MR arthrography, making the diagnosis of partial ligamentum teres tears difficult. High SI within the substance of the fibers and irregularity suggest partial tearing; however, further research is warranted.

Risk factors for ligamentum teres tears

PURPOSE

The purpose of this study was to examine the relationship between nontraumatic ligamentum teres (LT) tears and acetabular radiographic architecture.

METHODS

The inclusion criteria for this study were all patients who had anteroposterior pelvis radiographic views and had undergone arthroscopic examination of the LT. The exclusion criteria were Tonnis arthritic grade 3 and traumatic high-energy mechanisms of injury. Radiographic data were measured preoperatively on an anteroposterior pelvis view, including acetabular inclination (AI), lateral center edge (CE) angle, magnitude of cross-over sign, and ischial spine prominence. A Lateral Coverage Index (LCI) was defined as the center edge angle minus acetabular inclination. Hips were divided into 3 groups according to the LCI: (1) high: 34° and above; (2) medium: 19° to 33°; and (3) low: below 19°.

RESULTS

Of the 463 hips (430 patients) included in the study, 226 (49%) had a partial- or full-thickness LT tear. Patients with tears were significantly older than patients without tears (P < .0001), with average ages of 38 and 33 years, respectively. Radiographically, patients with tears had less acetabular retroversion, as reflected by lower ischial spine prominence values and lesser cross-over signs (P = .01 and .0005, respectively). Using the LCI, 115 hips (25%) were classified as high, 236 (50%) as medium, and 114 (25%) as low. Hips with low LCI were 1.74 times more likely to have LT tears than high LCI hips.

CONCLUSIONS

This study found that the presence of LT tears was associated with acetabular bony morphology and age. LT tears were less frequent with high LCI and acetabular retroversion and less frequent in patients younger than 30 years. Further study is needed to establish whether there is a causal relationship between acetabular undercoverage and LT tears and whether LT tears may be a sign of microinstability of the hip.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

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

PURPOSE

The purpose of this study was to investigate whether patients who have undergone surgical hip dislocation with excision of the ligamentum teres exhibited symptoms of a Type I ligamentum teres rupture.

METHOD

A questionnaire was designed to enquire about specific symptoms attributed to Type I injuries (complete rupture) in the literature: gross instability, incomplete reduction, inability to bear weight and mechanical symptoms. 217 consecutive patients were surveyed and 161 patients (75%) returned 168 questionnaires (75%). Mean age was 34 and median follow-up was 51 months (35 to 97).

RESULTS

All patients were able to fully weight bear after surgery while 77% experienced no groin pain and 61% experienced no pain on exercise. 35% of patients experienced popping and locking in their operated hip and 24% had subjective feeling of their hip giving way.

CONCLUSION

Patients who have had surgical excision of the ligamentum teres during open osteochondroplasty for cam deformities do not exhibit symptoms of a Type I ligamentum teres rupture. Our results show that minor instability symptoms may be present but symptoms present more like to Type II (partial) injuries. We propose that Type II injuries be divided into Type IIa; partial tear and Type IIb; iatrogenic rupture.

Arthroscopic ligamentum teres reconstruction using semitendinosus tendon: surgical technique and an unusual outcome

Although the exact biomechanical function of the ligamentum teres (LT) remains unclear, an important role in hip stability has been suggested. In some patients, perhaps because of their specific anatomy or physical activity, it seems to have a major function as a hip stabilizer. Therefore, after a complete LT tear, this group of patients may have persistent hip pain and mechanical symptoms probably related to microinstability and subtle subluxation. We present the case of a female patient with a complete LT tear. This had been treated by debridement and anterior capsule tightening, followed by prolonged rehabilitation. However, she had persistent symptoms. An LT reconstruction with a novel surgical technique was performed. The LT was reconstructed with double-stranded semitendinosus graft. The acetabular end was fixed with 2 anchors, and the femoral end was passed into a bone tunnel and fixed with an interference screw. After surgery, the patient's modified Harris Hip Score and Non-Arthritic Hip Score improved from 53 and 73 to 100 and 95, respectively, at 12 months of follow-up. At repeat arthroscopy 15 months after surgery, it was observed that the graft had resorbed, although the 2 Ticron stitches (Covidien, Mansfield, MA) remained firmly attached and were still acting as a small synthetic ligament.

[Coxarthrosis - a radiological approach and guidelines]

CLINICAL/METHODICAL ISSUE

Coxarthrosis is one of the most frequent indications in radiological practice with a prevalence as high as 8%.

STANDARD RADIOLOGICAL METHODS

Radiography, sonography, computed tomography, magnetic resonance imaging.

METHODICAL INNOVATIONS

Magnetic resonance arthrography for detection of early stages of labral and chondral pathologies as well as detection of osteonecrosis at an early stage.

PERFORMANCE

Czerny C, Hofmann S, Neuhold A et al. (1996) Lesions of the acetabular labrum: accuracy of MR imaging and MR arthrography in detection and staging. Radiology 200(1):225-230. Czerny C, Oschatz E, Neuhold A et al. (2002) [MR arthrography of the hip joint]. Radiologe 42(6):451-456. Kramer J, Breitenseher M, Imhof H et al. (2000) [Diagnostic imaging in femur head necrosis]. Orthopade 29(5):380-388.

ACHIEVEMENTS

Is already established in clinical practice.

PRACTICAL RECOMMENDATIONS

Each modality has relevant indications.

Ligamentum teres: a functional description and potential clinical relevance

PURPOSE

The primary purpose of this study was to investigate the role the ligamentum teres has in providing hip stability using a biomechanical model. The second purpose was to review arthroscopic findings in those with a complete ligamentum teres rupture and question them regarding instability to determine how clinical findings related to the biomechanical model.

METHODS

A string model was created to examine ligamentum teres excursion during various hip positions. A retrospective review of 350 consecutive surgical patients identified 20 subjects with a complete ligamentum teres rupture that was not repaired at the time of surgery.

RESULTS

The model found the ligamentum teres to have the greatest excursion when the hip was externally rotated in flexion (ER/FLEX) and internally rotated in extension (IR/EXT). During operative assessment, it was noted that all 20 subjects had laxity during dynamic impingement testing when their hip was in a position of ER/FLEX. Nine (45%) of the 20 subjects with ligamentum teres rupture were available for follow-up (mean 31 months post-op). Five out of these 9 subjects noted instability: 5 of 9 with squatting (ER/FLEX) and 4 of 9 with crossing one leg behind of the other (IR/EXT). These 5 subjects had osseous risk factors that compromised hip stability including inferior acetabular insufficiency.

CONCLUSIONS

The ligamentum teres may contribute to hip stability when the hip is in ER/FLEX and IR/EXT. Individuals with osseous risk factors for instability, including inferior acetabular insufficiency, may have instability with squatting (ER/FLEX) and crossing one leg behind of the other (IR/EXT).

LEVEL OF EVIDENCE

IV.