Morphometric Study Of Distance Between Posterior Superior Iliac Spine And Ischial Tuberosity Of The Human Hip Bone

Objective: To do study the distance between Posterior superior Iliac Spine and Ischial tuberosity (PSIS-IT) of human hip bone for determination of sex. Methods: The study comprised unpaired 272adult human hip bones of known sex. The posterior superior iliac spine and ischial tuberosity were identified in all the hip bones and a slidingcaliper was used to measure the distance between them. Results: The raw data obtained was statistically analyzed. Range, mean, standard deviation and standard error of mean were determined for parameter. Conclusion: It was observed that out of 272 hip bones taken for study 160 were of males and 112 were of females. The Mean distance in males was observed to be greater in comparison to females. Statistically calculated t- test reveals that the parameter taken for study is very highly significant in terms of sex differentiation.

An Analysis of Location of Needle Entry Point and Palpated PSIS in S1 Nerve Root Block

BACKGROUND: The first sacral nerve root block (S1NRB) is a common procedure in pain clinic for patients complaining of low back pain with radiating pain. It can be performed in the office based setting without C-arm. The previously suggested method of locating the needle entry point begins with identifying the posterior superior iliac spine (PSIS). Then a line is drawn between two points, one of which is 1.5 cm medial to the PSIS, and the other of which is 1.5 cm lateral and cephalad to the ipsilateral cornu. After that, one point on the line, which is 1.5 cm cephalad to the level of the PSIS, is considered as the needle entry point. The purpose of this study was to analyze the location of needle entry point and palpated PSIS in S1NRB. METHODS: Fifty patients undergoing C-arm guided S1NRB in the prone position were examined. The surface anatomical relationships between the palpated PSIS and the needle entry point were assessed. RESULTS: The analysis revealed that the transverse and vertical distance between the needle entry point and PSIS were 28.7 +/- 8.8 mm medially and 3.5 +/- 14.0 mm caudally, respectively. The transverse distance was 27.8 +/- 8.3 mm medially for male and 29.5 +/- 9.3 mm medially for female. The vertical distance was 1.0 +/- 14.1 mm cranially for male and 8.1 +/- 12.7 mm caudally for female. CONCLUSIONS: The needle entry point in S1NRB is located on the same line or in the caudal direction from the PSIS in a considerable number of cases. Therefore previous recommended methods cannot be applied to many cases.

Comparison of the Spinal Level Assumption by Palpation of the Iliac Crest and Posterior Superior Iliac Spine

OBJECTIVE: To compare the clinical usefulness of the posterior superior iliac spine (PSIS) with that of iliac crest (IC) for identifying the lumbar vertebral level. METHOD: Lumbar spine level was identified by the line connecting bilateral upper margin of iliac crests in the antero-posterior lumbar X-rays of 120 patients. Assumed IC level and assumed PSIS level were compared by 3 examiners' palpation in 60 patients. A marker was taped on assumed IC level and assumed PSIS level by 4 examiners and the postero-anterior lumbar X-rays was taken in randomly distributed 50 patients. RESULTS: IC intersection line was ranged from the L4 spinous process to the L5-S1 interspinous process in all patients. Inter- examiner agreement of palpation was significantly greater in PSIS than IC level (p<0.05). The marker indicating assumed IC level was higher than true IC level in all patients and was higher than L3-4 interspinous process in 8%. CONCLUSION: We may use PSIS level for assumption of the lumbar vertebral level to compensate for the limitation of iliac crest palpation, but at the same time keep in the mind the variarity of the PSIS level.