Reliability, life cycle and corrective action

I took a hiatus this past week to have my left hip replaced.

My reliability for movement had deteriorated significantly, but slowly, over the past 12 months, finally culminating in corrective action, e.g. replacement of the joint.

The right hip was replaced 5 years ago, at the same facility, but under different circumstances.

At that time, as a FTE, there was absolutely no tolerance for loss of movement reliability as the work required frequent travel, including international, with visitations, and mandatory tours of manufacturing facilities, some quite massive, height and breadth.

Hip joints wear out.

Some 400,000 hip replacement surgeries are performed each year in the US (https://www.cnn.com/2018/03/06/health/hip-knee-replacement-surgeries-earlier-study/index.html) and knee replacements exceed that number by almost double.

Osteoarthritis, the culprit, is caused by inflammation in the joint, quite like heat in a mechanical rotating device.

Just as in a bearing excessive heat causes failure.

In the case of a hip joint, blood tries to carry the excess heat away, but the source of the inflammation has still not been identified or corrected and eventually a full hip replacement is the solution

Design of the joint has obviously taken eons and has stood the test of time, for most.

Perhaps, if given priority early in the hip’s life cycle, a physical regime, including avoiding certain movements, can prolong the life cycle, if all the other variables, e.g. load (weight, movement), climate, diet remain the same.

In this case none of the variables remain constant, much like a bearing in the real world, so condition monitoring is necessary to provide minimum notification of further functional failure.

Physical exams, X-rays, MRIs follow, all condition monitoring technologies.

Avoiding corrective maintenance (total hip replacement) becomes the goal, necessitating changes in lifestyle in order to provide functional ‘reliability’.

Some changes, weight loss, affecting load on the joint, are not so easy, so less that fully functional becomes the norm.

Inflammation reduction can be partially achieved with different remedies.

A cane helps with offsetting load distribution but creates other issues with the body’s structure.

In the end corrective action (in this case total replacement) is required.

The new joint has been designed for reliability, including its materials of construction.

The replacement joint likely has less life cycle duration as the original and is non-biological, composed of uniquely designed components that mimic the original but requiring no blood supply.

The replacement process is performed by an exceptional mechanic (and team) who precisely aligns the geometry required to duplicate the original function.

A saw is used, a grinder, a screwdriver and sometimes a hammer if the spike requires a little more force.

Cleanup of the job site is paramount to success.

At the end, the new joint performs accordingly and with no pain, functional reliability is restored, a life cycle is restored albeit shorter term than the original had intended.

You are back to work. The shutdown is over.

The mechanic (and team) did their jobs well.

Hooray!