Safety and efficacy of intraarticular hip injection using anatomic landmarks

This study tests the hypotheses that the hip can be injected safely and reliably, using anatomic landmarks, without fluoroscopic guidance. Fifteen human cadavers (30 hips) were injected, each receiving one anterior hip injection and one lateral hip injection with methylene blue dye. Anatomic dissections were done on all 30 specimens to determine the rate of success and the proximity of the needle to the neurovascular structures about the hip with each approach. Neither the anterior nor the lateral injection approach, using published techniques based on anatomic landmarks, was sufficiently reliable to recommend for clinical use without radiographic guidance; the anterior approach was successful in only 60% of injections, and the lateral technique was successful in 80% of injections. In addition, the anterior approach, which is recommended in more reference works than any other approach, resulted in significantly more risk to the femoral nerve than did the lateral approach. The needle pierced or contacted the femoral nerve in 27% of anterior injections and was within 5 mm of the femoral nerve in 60% of anterior attempts. The anterior injection approach also resulted in needle placements significantly closer to the femoral artery and the lateral femoral cutaneous nerve than did the lateral approach. Using the lateral approach, the needle was never within 25 mm of any neurovascular structure in any injection. Some form of radiographic or sonographic guidance is recommended for needle placement during hip injections and aspirations; the lateral approach for needle placement seems safer than the anterior approach, with respect to the possibility of neurovascular injury.     

Prediction of the location of the centre of rotation of the hip joint external landmarks

AIM: The object of this study was to develop a new method to predict the location of the centre of rotation of the hip joint reasonably accurately. METHOD: We collected the coordinates of palpable bony landmarks in 50 patients, 25 males and 25 females, using CT scans to predict the physiological location of the centre of the hip joint centre. RESULTS: The centre of the hip was located, on average, at 12% (+/- 2.9) of the inter-ASIS (anterior superior iliac spine) distance medial, 33% (+/- 3.9) distal and 19% (+/- 2.7) posterior to the anterior superior iliac spine (ASIS). CONCLUSION: Knowledge of the physiological centre of rotation of the hip may be useful in navigation of the cup in total hip arthroplasty.     

Using intraoperative pelvic landmarks for acetabular component placement in total hip arthroplasty

Dislocation after total hip arthroplasty is frequently due to acetabular malpositioning. Positioning of the acetabular component using anatomical landmarks may reduce the incidence of dislocation from improper acetabular orientation. The pelvis provides 3 bony landmarks (ilium, superior pubic ramus, and superior acetabulum), which, when used to define a plane, allows cup orientation in abduction and version. Landmarks evaluated in 24 cadaveric acetabuli allowed slightly increased abduction and anteversion of the cup, compared with native acetabuli. Six hundred seventeen primary total hip arthroplasties were performed between 1996 and 2003 using this technique. Mean cup abduction was 44.4 degrees with 13.2 degrees of anteversion. This technique allows satisfactory reproducible cup orientation based on individual pelvic morphology. Review of patient outcome data suggest high patient satisfaction and lower dislocation rate without additional equipment, time, or cost.     

Are anatomic landmarks reliable in determination of fusion level in posterolateral lumbar fusion?

STUDY DESIGN: Determination of the fusion level by direct observation and palpation of anatomic landmarks is compared with the finding obtained from a lateral intraoperative radiograph. OBJECTIVES: To assess the reliability of the use of intraoperative anatomic landmarks in determination of the fusion level. SUMMARY OF BACKGROUND DATA: Accurate determination of the level to be fused in noninstrumented posterolateral fusion is crucial. No studies are available in which the value of direct observation and palpation of the anatomic landmarks in determination of the fusion level has been assessed. METHODS: Eighty patients who underwent posterolateral fusion without instrumentation in the lumbosacral spine were included in this study. During surgery, first, the cephalad transverse process at the desired level to be fused was determined by direct observation and palpation of the anatomic landmarks; second, a metal mark was placed beneath the cephalad transverse process at the level determined by anatomic landmarks. This was followed by a lateral radiograph. The consistency and discrepancy between the use of the anatomic landmarks and lateral radiography in determining the desired fusion level were recorded. RESULTS: The fusion level determined by direct observation and palpation of the anatomic landmarks was accurate in 76 (95%) cases. In the remaining four cases, intraoperative x-rays determined that the selection of the cephalad transverse process for fusion was one level too high in three cases and one level too low in the other case. All errors in determination of the level to be fused occurred in patients who had extensive laminectomy at L4-S1. CONCLUSIONS: Determination of fusion level by direct observation and palpation of the anatomic landmarks is not reliable in patients who have had or require decompressive procedures. A lateral radiograph should be routinely obtained for accurate identification of the level to be fused.     

Localization of the arcuate line from surface anatomic landmarks: a cadaveric study

The arcuate line is a relevant structure when reconstructing the abdominal wall after rectus abdominis musculocutaneous flap harvest. Its location is classically taught to be half the distance from the pubic symphysis to the umbilicus, but recent anatomic literature provides evidence to the contrary. Better understanding of the relationship between the arcuate line and surface anatomic landmarks could facilitate better preoperative planning when harvesting a rectus abdominis musculocutaneous flap. A total of 32 arcuate lines were dissected in 18 cadavers, and the location was correlated to various surface anatomic landmarks. The arcuate line was found to lie at 74.6% of the distance from the pubic symphysis to the umbilicus, and 32.7% of the distance from the pubic symphysis to the xiphoid. This location was 1.8 +/- 1.7 cm superior to the level of the anterior superior iliac spines (ASIS). This study provides further support for the finding in the anatomic literature that the arcuate line is substantially more superior than classically described. This knowledge may prove useful in preoperative planning of rectus abdominis musculocutaneous flap harvest.     

Radiographic determination of the anatomic hip joint center: A cadaver study

We studied 31 human pelvic cadaver specimens with 57 intact hip joints. The teardrop, which represents the inferior portion of the acetabular notch, was identified as also was the center of rotation in the articulating femoral head. The pelvic height and the horizontal and vertical distances between the acetabular notch and the hip joint center were measured. We found the center of rotation of the hip joint to be 13 percent of the pelvic height lateral and 7 percent of the pelvic height superior to the teardrop. No sex difference was found.     

Accuracy of determination of the hip centre in navigated total knee arthroplasty

AIM: In navigated knee arthroplasty the hip centre is determined by rotary motion of the femur (pivoting). The accuracy of this functional hip centre determination in vivo is unclear. In the following paper the accuracy of pivoting in the determination of the hip centre was examined. METHODS: Navigated (TC-PLUS, Solution, PLUS Orthopedics) total knee arthroplasty (PI Galileo, PLUS Orthopedics) was performed on 25 patients with primary arthritis of the knee joint. The position of the femoral component and the hip centre were postoperatively determined by computer tomography. Through comparison with the intraoperatively documented data, the deviation of the pivoted from the true hip centre in the frontal and sagittal planes was calculated. The degree of arthritis of the hip was determined on plain radiographs according to Kellgren. RESULTS: The mean deviation was determined to 1.0 +/- 0.7 degrees in the frontal plane and 2.5 +/- 1.6 degrees in the sagittal plane (p = 0.002). This corresponds to a mean overall deviation of 20 +/- 10 mm. The data were continuously, non-parametrically distributed without any outliers. A great range of motion (ROM) in the frontal as well as sagittal planes during pivoting resulted in a less accurate determination of the hip centre. There was no correlation to the degree of arthritis of the hip. CONCLUSION: The results indicate a recommendable ROM during pivoting for maximal accuracy of hip centre determination of 20 to 30 degrees in the sagittal plane and 30 to 40 degrees in the frontal plane. Arthritis of the hip is not a contraindication for functional determination of the hip centre.     

Transverse anatomic landmarks for the A1 pulley of the thumb

Background  

Triggering of the thumb is a common entity resulting in pain and disability. Operative management requires accurate knowledge of the pulley system for proper release of the A1 pulley. The purpose of this study was to predict the location of the A1 pulley with surface anatomic landmarks while avoiding injury to the neurovascular bundles and the critical oblique pulley.     

Anatomic landmarks of the glossopharyngeal nerve: a microsurgical anatomic study

OBJECTIVE: Compared with other lower cranial nerves, the glossopharyngeal nerve (GPhN) is well hidden within the jugular foramen, at the infratemporal fossa, and in the deep layers of the neck. This study aims to disclose the course of the GPhN and point out landmarks to aid in its exposure. METHODS: The GPhN was studied in 10 cadaveric heads (20 sides) injected with colored latex for microsurgical dissection. The specimens were dissected under the surgical microscope. RESULTS: The GPhN can be divided into three portions: cisternal, jugular foramen, and extracranial. The rootlets of the GPhN emerge from the postolivary sulcus and course ventral to the flocculus and choroid plexus of the lateral recess of the fourth ventricle. The nerve then enters the jugular foramen through the uppermost porus (pars nervosa) and is separated from the vagus and accessory nerves by a fibrous crest. The cochlear aqueduct opens to the roof of this porus. On four sides in the cadaver specimens (20%), the GPhN traversed a separate bony canal within the jugular foramen; no separate canal was found in the other cadavers. In all specimens, the Jacobson's (tympanic) nerve emerged from the inferior ganglion of the GPhN, and the Arnold's (auricular branch of the vagus) nerve also consisted of branches from the GPhN. The GPhN exits from the jugular foramen posteromedial to the styloid process and the styloid muscles. The last four cranial nerves and the internal jugular vein pass through a narrow space between the transverse process of the atlas (C1) and the styloid process. The styloid muscles are a pyramid shape, the tip of which is formed by the attachment of the styloid muscles to the styloid process. The GPhN crosses to the anterior side of the stylopharyngeus muscle at the junction of the stylopharyngeus, middle constrictor, and hyoglossal muscles, which are at the base of the pyramid. The middle constrictor muscle forms a wall between the GPhN and the hypoglossal nerve in this region. Then, the GPhN gives off a lingual branch and deepens to innervate the pharyngeal mucosa. CONCLUSION: Two landmarks help to identify the GPhN in the subarachnoid space: the choroid plexus of the lateral recess of the fourth ventricle and the dural entrance porus of the jugular foramen. The opening of the cochlear aqueduct, the mastoid canaliculus, and the inferior tympanic canaliculus are three landmarks of the GPhN within the jugular foramen. Finally, the base of the styloid process, the base of the styloid pyramid, and the transverse process of the atlas serve as three landmarks of the GPhN at the extracranial region in the infratemporal fossa.     

The effect of pelvic movement on the accuracy of hip centre location acquired using an imageless navigation system

Objective  

The aim of this study was to assess the accuracy of an imageless navigation system in localising the hip centre and to evaluate the effect of pelvic movement on the accuracy of hip centre acquisition.     

Influence of anatomic landmarks in the virtual environment on simulated angled laparoscope navigation

Background  

The aim of this study is to investigate the influence of the presence of anatomic landmarks on the performance of angled laparoscope navigation on the SimSurgery SEP simulator.