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Arthroscopic hip preservation surgery
Published in K. Mohan Iyer, Hip Preservation Techniques, 2019
Loss of labral function, either via tear or debridement, may induce hip microinstability, subluxation, or dislocation. Breakage of the labral fluid seal is the rationale behind loss of joint stability.9,10 Labral preservation, particularly with larger tears, may be important for maintaining hip stability.11 The ligamentum teres connects the center of the femoral head to the acetabular fossa, and lesions of the ligamentum teres are being increasingly recognized as a cause of persistent hip pain, particularly due to microinstability.
Advances in Hip Arthroscopy
Published in K. Mohan Iyer, Hip Joint in Adults: Advances and Developments, 2018
Under the influence of joint compression in a neutral hip position, the acetabular labrum continues to resist femoral head dislocation despite detachment from the acetabular rim. A radial tear in the acetabular labrum decreases adjacent labral strain, but removal of 2 cm or more of the acetabular labrum is needed before hip stability decreases [10]. Loss of labral function, either via tear or via debridement, may induce hip microinstability, subluxation or dislocation. Breakage of the labral fluid seal is the rationale behind loss of joint stability [9]. This may occur in hips with FAI or dysplasia during flexion and rotational manoeuvres. Although the majority of labral tears occur in the presence of osseous pathology, they may also occur without any obvious bony pathomorphology in patients performing certain sports or activities or in patients with iliopsoas impingement. Labral preservation, particularly with larger tears, may be important for maintaining hip stability [11]. Ligamentum teres connects the centre of the femoral head to the acetabular fossa. Lesions of the ligamentum teres are being increasingly recognised as a cause of persistent hip pain, particularly due to microinstability.
Lower Limb
Published in Harold Ellis, Adrian Kendal Dixon, Bari M. Logan, David J. Bowden, Human Sectional Anatomy, 2017
Harold Ellis, Adrian Kendal Dixon, Bari M. Logan, David J. Bowden
These two views, anterior and posterior, show the general principles of the pelvic girdle well. Note how the femoral head (two-thirds of a hemisphere) is much better contained within the acetabular fossa than the humeral head, thereby providing stability at the expense of mobility. The obliquity of the acetabulum means that the femoral head can just be seen on the anterior view, but not posteriorly.
Comparison of the accuracies of computed tomography-based navigation and image-free navigation for acetabular cup insertion in total hip arthroplasty in the lateral decubitus position
Published in Computer Assisted Surgery, 2021
Masahiro Hasegawa, Shine Tone, Yohei Naito, Hiroki Wakabayashi, Akihiro Sudo
The hips were divided into two groups based on the registration points for image-free navigation (Image free Hip 6.0 navigation system, Brainlab). In Group I, the ipsilateral ASIS and the spinous process of the L5 vertebra were registered in 31 hips before November 2014. In Group II, bilateral ASIS points were registered in 32 hips after December 2014. A reference array was fixed onto the iliac spine on the treated side using two 4 mm Schanz screws. In Group I, the patient positioner was placed at a location that ensured free access to the spinous process of the L5 vertebra, which was used as a reference point on the mid sagittal plane. After the preparation of the patient, the L5 landmark was digitized through the drapes. The ASIS on the treated side was re-acquired to exactly reproduce the point acquisition process for a clinical setup performed in the lateral decubitus position. The distance between the ASIS was measured and entered onto the system. In Group II, the treated ASIS and non-treated ASIS were acquired on the tissue according to this pelvic reference in a semi-sterile environment, i.e. the area around the pelvic reference array was draped, whereas the other areas remained non-sterile. After the acquisition of these landmarks, the pointer was discarded and the patient was finally prepared according to the standard surgical procedure in a lateral decubitus position. After removal of the femoral head, the acetabular fossa and the acetabular cavity were digitized. Additionally, a point directly located at the anterior side of the acetabular rim (anterior rim point) was acquired. After inserting the cup, the final cup orientation was verified by the navigation system, and the navigation system recorded the final cup orientation [19].
Deviation of cup alignment from target angle during press-fit insertion
Published in Computer Assisted Surgery, 2018
Yingyong Suksathien, Jithayut Sueajui, Urawit Piyapromdee
A right-handed surgeon (YS) with 20 years’ experience performing THA conducted all operations. Two small pins were inserted into the ipsilateral Anterior Superior Iliac Spine (ASIS) through a stab incision. The navigation tracker was attached to the pin adaptor and the bony landmarks (ASIS of both sides and pubic symphysis) were determined and digitalized with a metal pointer to define Anterior Pelvic Plane (APP) as the reference plane for the cup inclination and anteversion. We performed a modified Hardinge’s approach in all patients. After removal of the femoral head, the deepest point of the acetabular fossa was registered as an additional reference point. Then, by using the trial cup, the native inclination and anteversion angles of the acetabulum were determined. During reaming, the position of the reamer was acquired by the navigation system and the operating surgeon was provided with real-time information about the resulting position of the reamer (medialization, cranialization and antero-posterior direction) and its orientation (inclination and anteversion angles) in relation to APP as well as the native acetabulum. After reaching the design reaming size, the femoral stem was prepared and the stem anteversion angle was evaluated and recorded. The final cup was implanted and the operating surgeon was provided with real-time information about the cup position and orientation. Cup inclination angle was aimed at 40 degrees in all cases and the anteversion was aimed as individual native anteversion angle in each case, then we recorded the combined anteversion angle. The final cup was aligned at target angles in both inclination and anteversion, the tracker was detached from the insertion handle and the surgeon inserted the cup with hammer blows until it was seated completely. The tracker was attached again to display both inclination and anteversion angles and these angles were recorded. The surgeon was allowed to correct the cup orientation if there was any variation from target angle outside the Lewinnek’s safe zone [8] in each case, 40° ± 10° and 15° ± 10° for inclination and anteversion respectively. After finishing the cup, the femoral stem was inserted and the joint was reduced. Patients’ age, gender, diagnosis, side of operation, cup size, and number of supplemental screws were recorded as demographic data. Deviated Inclination Angles (DIA) and Deviated Anteversion Angles (DAA) in each case were calculated.