Effect of head size and rotation on taper corrosion in a hip simulator

Abstract

Aims This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads. Methods In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth. Results Overall, 36 mm heads had lower corrosion onset load (p = 0.009) and change in open circuit potential (OCP) during simulated gait with (p = 0.006) and without joint movement (p = 0.004). Discontinuing gait’s joint movement decreased corrosion currents (p = 0.042); however, wear testing showed no significant effect of joint movement on taper damage. In addition, 36 mm heads had greater corrosion area (p = 0.050), but no significant difference was found for maximum linear wear depth (p = 0.155). Conclusion Larger heads are more susceptible to taper corrosion; however, not due to frictional torque as hypothesized. An alternative hypothesis of taper flexural rigidity differential is proposed. Further studies are necessary to investigate the clinical significance and underlying mechanism of this finding. Cite this article: Bone Jt Open 2021;2(11):1004–1016.

The incidence of adverse local tissue reaction due to head taper corrosion after total hip arthroplasty using V40 taper and 36 mm CoCr head

“…Craig et al 37 reported a significant elevation of Co levels in Accolade I components in combination with CoCr heads of ≥ 36 mm compared with those of ≤ 32 mm. Increased taper corrosion due to larger metal heads (36 mm) was also reported by Wight et al 43 in an in vitro study using a hip simulator. Matharu et al 1 analyzed all revisions due to ARMD in the NJR (n = 3,340), and reported that the incidence of ARMD in non-MoM THA is notably higher in THAs with a 36 mm metal head compared with smaller head sizes.…”

New polyethylenes in total hip arthroplasty

“…Other authors have confirmed these results using CT analysis, 38,39 but there are contradictory results reported in young patients with HXLPEs. 40…”

“…We believe, as also suggested by Broomfield et al, 38 that rather than more than just the bearing surface, biological response and particle debris generation from modular implants may also play an important role in the low risk for hip revision in patients with HXLPEs. In a hip simulator study, Wight et al 40 were able to detect those femoral heads with a 36 mm diameter were more susceptible to taper corrosion than those with 28 mm. Interestingly, they found that the frictional torque may have a greater effect with adverse wear conditions, so larger femoral heads increased the risk of head-neck tribocorrosion even under pristine conditions.…”

Association between General Anesthesia and the Occurrence of Cerebrovascular Accidents in Hip Fracture Patients

“… General information: the general information extract form was established by the patients themselves, covering gender, age, BMI, mean body mass, marital status, place of residence, monthly income, educational degree, living habits, complications, and history of cerebrovascular accidents Incidence of cerebrovascular accidents: the diagnosis basis of cerebrovascular accidents was relevant standards in Internal Medicine (8 th edition) [ 14 ], and the patients should be diagnosed by brain CT and MRI Changes in hemodynamics: all patients received the tests of perioperative mean arterial pressure (MAP) and heart rate (HR), after entering the operating room, left radial artery cannulation was performed for pressure measurement, and before anesthesia ( T 1 ), 15 min after anesthesia ( T 2 ), at the time of skin incision ( T 3 ), and 15 min before the end of surgery ( T 4 ), the patients' MAP, HR, and saturated pulse oxygen (SpO 2 ) were recorded and compared Association between various risk factors under general anesthesia and the occurrence of cerebrovascular accidents: the association between general anesthesia and the occurrence of cerebrovascular accidents as well as between factors under general anesthesia including age, BMI, number of anesthetic drugs, intraoperative blood pressure, and HP and the occurrence of cerebrovascular accidents was analyzed …”

“…Incidence of cerebrovascular accidents: the diagnosis basis of cerebrovascular accidents was relevant standards in Internal Medicine (8 th edition) [ 14 ], and the patients should be diagnosed by brain CT and MRI…”