Tactile Feedback Comparison of Manual, Hammer, and Rotary Powered Needle Insertion Accuracy for Bone Marrow Biopsy and Other Procedures

For decades, clinicians have performed bone marrow sampling procedures by manually twisting and pushing auger-like devices into bones, with variable and less than ideal results. For the clinician, the bone marrow biopsy is generally a blind procedure during needle advancement without any dynamic visual reference, except the external view of the patient and the device. The clinician is required to feel the tissue levels, including bone of widely diverse densities, communicated via the needle to the hand. The procedure is relatively straightforward but substantial skill and experience are required by the operator to complete the procedure quickly, safely and effectively, with minimal pain to the patient. With the introduction of rotary power to access the intraosseous space, the question of needle tip control has been open to debate. Some clinicians question whether the ease of insertion with a rotary-powered device would lead to perforation of the opposite cortex of the bone and/or damage adjacent tissues.

The investigators sought to study the relative precision of anatomical placement of the needle tip in bones using only tactile feedback. The objective was to determine if clinicians were able to correctly place the needle tip into a specific target area of simulated bone more often and in less time when using rotary powered intraosseous devices than when using manually inserted devices, or hammer-assisted insertion devices, when relying primarily on tactile feedback to determine correct depth of penetration. Better tactile feedback with the rotary power would allow clinicians to accurately predict the level of control over needle placement. Additionally, needles inserted with rotary power would cause less damage to simulated bone than those inserted with manual or hammer-assisted techniques.

Three different FDA-cleared 11 gauge stainless steel needle types were compared in a randomized prospective study test blocks of artificial bone. The needle types were Manual inserted (Manual), Hammer-assisted (Hammer), and Rotary-powered inserted (Power). Test blocks were specifically designed of three different thicknesses each simulating the characteristics of human bone. Eleven clinicians participated in the study. Following each insertion, the participant was asked to rate his/her confidence level of insertion accuracy on a scale of 0 to 10. Position of the needle tip was assessed by fluoroscopic confirmation. Each participant also inserted each needle type into a simulated osteoporotic bone model (raw chicken egg). The ability to insert the needle into the osteoporotic model without damage was based on visual assessment. Data were analyzed using SPSS for Windows.

Each of the 11 participants used each of the three needle types (Manual, Hammer, and Power) on each of the three different simulated bone types, for a total of 9 insertions each. Total number of insertions for the study was 99 (9×11). Mean insertion times were Manual: 20.7 ± 10.1 seconds, Hammer: 12.7 ± 5.9 seconds, and Power: 8.7 ± 2.8 seconds. Differences were statistically significant (p<0.001). Insertion success by devices, defined as correct placement of the needle tip to a specific target depth, was Manual: 48.5%, Hammer: 69.7%, Power: 97.0%. Differences were statistically significant (p<0.001). On a scale of 0 to 10, mean insertion certainty levels, defined as the clinicians perception of needle tip placement into the correct location, by devices were Manual: 48% certainty, Hammer: 61% certainty, and Power: 91% certainty. All certainty comparisons between devices were statistically significant (p<0.05). Using a raw egg to simulate osteoporotic bone, insertion rates without damage were Manual: 19.2%, Hammer: 36.4%, and Power: 100%. Differences were statistically significant (p<0.001).

Correct placement of a bone biopsy needle into a precise target area using tactile feedback only was markedly better and faster when using a rotary powered needle than when using a Manually inserted or a Hammer assisted device. The operator's impression of correct needle placement correlated with actual control of needle placement. Damage to fragile bone models was negligible with the Powered device compared to marked damage from the Manual and Hammer devices. These findings may have far reaching clinical applications when determining the best method for performing bone marrow biopsies.

Miller:Vidacare Corporation: Employment, Equity Ownership, Patents & Royalties. Bolleter:Vidacare Corporation: Consultancy, Employment, Equity Ownership, Patents & Royalties. Philbeck:Vidacare Corporation: Employment. Montez:Vidacare Corporation: Employment.