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The impact of neuromuscular blocking agents on traction forces during total hip replacement surgery

Patients undergoing hip replacement surgery: impact of neuromuscular blockade on the forces required for visualization of the femoral neck.

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ANZCTR
Registry ID
ACTRN12615000103561
Enrollment
20
Registered
2015-02-05
Start date
2014-10-31
Completion date
2015-10-30
Last updated
2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Orthopaedic surgeons frequently claim that the administration of muscle relaxants (NMBA) in patients under general anaesthesia facilitate surgery, especially when significant forces may be required (e.g. dislocation of hip joint, femoral realignment during operation of femoral fractures). However, despite the fact that NMBA are frequently used during general anaesthesia for orthopaedic surgery, no evidence for their benefit on operating conditions exists. Therefore, this trial aims to investigate the influence of NMBA on traction forces during hip replacement surgery. 20 Patients scheduled for hip replacement surgery under general anaesthesia will be included in this trial. Patients will receive a standard general anaesthetic. Patients for this form of hip replacement surgery are generally operated on a special operating table with the patients feet placed in shoe-like brackets. This allows the application of significant tension and torque to the patients operated leg in order to enable the surgical preparation of the hip joint for the prosthesis. With the help of a measurement instrument (Newton Meter installed within the traction mechanic of the operating table) we will measure the forces required to extend a patient's leg to facilitate surgery. Thereafter, an NMBA (rocuronium = most often used NMBA at RPH) will be slowly administered to finally achieve muscle paralysis. During the time of paralysis development, traction forces on the leg will be measured. Aim is to investigate whether NMBA can significantly reduce the forces required during hip replacement surgery.

Interventions

Patients scheduled for elective hip replacement surgery under general anaesthesia will be included. At the start of surgery, at the time the surgeon request a pulling force (via traction table) on a patients leg to expose the femoral neck, the previously non-paralysed patient will receive rocuronium 0.6 mg/kg intravenously. Traction forces will be measured in Newton via an electronic strain gauge build into the traction system and connected to a laptop pc.

Sponsors

Thomas Ledowski
Lead SponsorIndividual

Study design

Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)

Eligibility

Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

scheduled for hip replacement surgery under general anaesthesia

Exclusion criteria

neuromuscular disease, regional or spinal anaesthesia, paralysis at start of surgery

Outcome results

None listed

Source: ANZCTR · Data processed: Feb 4, 2026