Abstract

A number of postoperative complications of navigated total knee arthroplasty have been discussed in the literature, including tracker pin site infection and fracture. In this paper we discuss the low postoperative complication rate in a series of 3100 navigated total knee arthroplasties and the overall complication rate in a systematic analysis of the literature.

I never considered this to be a significant problem if it is noticed. (back to that later)

Aaron Rosenberg's report seems to have agreed, but at the last members meeting of the Knee Society, Boston, September 2009, others had experience that contradicted my view.

With their experience, ultimately the results were very substantially compromised. This video and presentation show you how to avoid a bad result, actually obtain a perfect result, if you or your student assistant, resident or fellow, bags the MCL.

There are three important points. (1) One needs to recognise the occurrence. (2) The setting is usually varus and so direct end-to-end repair cannot be depended upon. (3) Use of a semitendinosis tenodesis, together with an imperfect, distracted direct repair works perfectly well!

(1) Recognition: The setting is usually varus, but I have had one case in which the chief resident, working with the fellow succeeded in getting the MCL in a valgus knee! In this usually tight varus setting the key feature is that at some point in the case, before component placement, one notices that the exposure is all of a sudden better! Now, the guilty resident or just a passive assisting resident/fellow will usually disagree. The extension space is not so obviously lax, but the flexion space is. Secondly, you do not feel an intact ligament in flexion. And, to prove it I have had to do a little more exposure of the superficial MCL to show the tear. There are at least three mechanisms. Most common is a saw cut. Next is possibly injury with the scalpel or cutting cautery during exposure, and last is damage essentially pre-operatively by a very sharp medial osteophyte which has thoroughly abraded the ligament.

Laxity in full flexion is not necessarily obvious as the posterior capsular integrity helps hide the instability. Again, the really intact ligament is well felt, and in the situation of laceration, the tibia pulls forward more on the medial side, the medial flexion space opens, and what was usually a tight exposure gets suddenly better.

(2) When varus is the setting, I have found it impossible or at least uncomfortable to depend upon direct repair. When the soft tissues are needing to be released or simply undergoing more stress than usual and a lot more than on the lateral side, I see it as unwise to expect or depend upon only a medial repair to hold.

(3) The semitendinosis tenodesis has worked essentially perfectly in every one of my cases. These patients have had no post-operative instability and they have had better than average to extremely good ROM.

A presumably key point is not to alter the patient's post-operative regimen! And, to avoid some passive alteration of PT, I advise specifically that the surgeon or those in his/her team do not mention the occurrence to the patient, the family or the PT! I put the whole story in the op-note, and weeks later I will specifically tell the patient what the staple in place is all about.

During the development and early use of the First Generation of Universal Total Knee Replacement Instruments, those instruments supplied with the PCA knee and also available for use with the Kinematic and Total Condylar knees, David Hungerford and I noticed our imperfection in balancing some varus and valgus deformed total knee patients.

We decided to start ligament tightening procedures to address this problem.

I became impressed with the potential difficulty of simply grasping the medial capsular ligamentous sleeve and pulling it distally on the proximal tibia so that it could be stapled in place. I thought that use of a suture and then incorporation of that suture with a staple or screw could enhance the fixation.

The tissue we were working with and are now talking about is rather thin, 1mm to 2mm, flat and broad with longitudinal fibers running in a caudad-cephalad direction.

I wanted some way to grab these longitudinal fibers and exert a distal pull without having the suture material pull through. This suggested the use of a locking loop, analogous to what I had seen in my training when locking stitches were commonly used on different layers of wound closure. I developed in my head the picture of a row of locking loops and then saw the cross-over to the other side which revealed the entire structure with trailing tails.

At this writing, I am uncertain of the year, but I am thinking it was 1982.

Soon after that I illustrated it with OR suture thru paper and then began using it in surgery.

I felt that publication would require studies of relative pull-out strength, and we added an injection study to look at possible influence of the tissue vascularity.

For tensile strength we used #5 Ethibond in bovine xenograft material, stapled and sewn to wood. In summary, different from individual stitches or stapling without stitching, The K-stitch fails at the suture material and not by pulling the tissue. This statement is true when the suture reasonably matches the heft or thickness and strength of the soft tissue. Otherwise one is dealing with suture that is overpoweringly stronger than the tissues being fixed or held.

Clearly this stitch has found common application in Achilles tendon repair and a wide variety of other applications. My own most common use is with re-attachment of the gluteus minimus tendon after an anterolateral total hip exposure.

I imagine that this suture is used or at least known by all orthopaedic surgeons with one exception, spine surgeons. I just do not see an application in their surgery. However, some of the younger ones will know it from their general orthopaedic training.

A video is shown of the technique and it is emphasised that the suture need not be used so that it loops the edge of a tendon. It may just as easily and helpfully be used on a broader surface as shown.

Dall-Miles cables were introduced in 1985 by Stryker Orthopedics for reattachment after greater trochanteric osteotomy. Prior fixation for greater trochanteric osteotomies was obtained with stainless steel monofilament wire, routinely used by Sir John Charnley. The cables were clearly much stronger. This system consisted of a rectangular four clawed grip and two cables. Two cables were passed thru the claw and around the medial aspect of the upper femur, as well as around the neck or under the collar of a femoral component. A tensioner was devised which would distract opposite ends of one cable, and a powerful squeezing device is used to fix rigidly the cable so that it remained securely held in the claw. In addition, “sleeves” were developed—small rectangular solids made of cobalt-chrome with two parallel holes going from end to end. Two ends of cable are passed thru the holes, pulled tight and locked by using the squeezing tool, the “crimp”, which holds the cables very securely in the desired position.

All of this worked much better than the wiring technique. However, it needed some additional features. The vertical pull of the abductor musculature was not optimally opposed by the cerclage aspects going thru the cross pieces in a largely lateral to medial direction. The vertical pull could relatively easily displace the trochanteric fragment.

I solved this problem by incorporating a secure distal cerclage cable whose tails were taken to and passed thru the lower bar (cross piece) of the grip. The ends of this cable coming thru the lower cross piece are pulled, distracted away very tightly and the lower cross piece is crimped, holding the cable securely. That cable is then passed around the shaft of the femur and cerclaged tightly, using a simple sleeve, tightly crimped.

This technique was published in this citation. Krackow, KA. A Technique for Improved Dall Miles Trochanteric Re-attachment.

Polyethylene damage, including normal wear, may occur for a variety of reasons. The opposing view would have one believe that all of those reasons are malignant and lead to unavoidable, reasonably short term failure.

The logical question is first whether simple spacer change has any clinical advantage, e.g. being a smaller operation, easier to rehab, recoup from, and sparing the unavoidable bone loss associated with the removal of ostensibly firmly fixed components. It is clear that all of these 3 or 4 points are true. That is, spacer change is a small procedure, characterised by all the points mentioned.

The only relevant questions are whether main component removal is necessary all the time because there is a more basic problem that portends rapid failure or because failure to take advantage of one-staging to a more extensive revision early, makes that more extensive revision impractical or more difficult for the patient when delayed any given number of years.

The answers to these last two considerations or questions are clearly no.

A bad batch of poly can lead to osteolysis or wear independent of malalignment or ligament imbalance. It should be treated by poly change and where appropriate bone grafting.

Poly wear in the presence of malalignment of some degree can be more controversial. Factors to consider should be (i) the availability of presumably improved poly from the given manufacturer, (ii) the amount of malalignment, (iii) the age of the patient, and (iv) any prospects for changing the alignment short of main component revision. The latter can be done with asymmetric poly, or for femoral malalignment, correction of that alignment with osteotomy, in selected instances.

The patient age factor relates to both ends of the spectrum. In the younger patient one wants not to waste current main components, i.e. prematurely move to the patient's next prosthesis. And, the very elderly patient may have a clinical situation well suited to the smaller operation and a life expectancy that would exceed the albeit imperfect durability of a residually malaligned spacer change.

So, even if most spacer changes do not last as long as ordinary primary components, that does not mean that none will. Nor does it mean that they will not last long enough in an extremely elderly patient.

During the development and early use of the First Generation of Universal Total Knee Replacement Instruments, those instruments supplied with the PCA knee and also available for use with the Kinematic and Total Condylar knees, David Hungerford and I noticed our imperfection in balancing some varus and valgus deformed total knee patients.

We decided to start ligament tightening procedures to address this problem

I became impressed with the potential difficulty simply of grasping the medial capsular ligamentous sleeve and pulling it distally on the proximal tibia so that it could be stapled in place. I thought that use of a suture and then incorporation of that suture with a staple or screw could enhance the fixation.

The tissue we were working with and are now talking about is rather thin, one to two millimeters, flat and broad with longitudinal fibers running in a caudad-cephalad direction.

I wanted some way to grab these longitudinal fibers and exert a distal pull without having the suture material pull through. This suggested the use of a locking loop, analogous to what I had seen in my training when locking stitches were commonly used on different layers of wound closure. I developed in my head the picture of a row of locking loops and then saw the cross-over to the other side which revealed the entire structure with trailing tails.

At this writing, I am uncertain of the year, but I am thinking it was 1982.

Soon after that I illustrated it with OR suture thru paper and then began using it in surgery.

I felt that publication would require studies of relative pull-out strength, and we added an injection study to look at possible influence of the tissue vascularity.

For tensile strength we used #5 Ethibond in bovine Xenograft material, stapled and sewn to wood. In summary, different from individual stitches or stapling without stitching, The K-stitch fails at the suture material and not buy pulling the tissue. This statement is true when the suture reasonably matches the heft or thickness and strength of the soft tissue. Otherwise one is dealing with suture that is overpoweringly stronger than the tissues being fixed or held.

Clearly uncemented hip stems are becoming more popular. They are working relatively well and avoiding the step of cementation is easier and much quicker. However, this speaker feels that well designed femoral stems with 25–30 years of proven successful fixation are perfectly good for elderly patients with 10, 15, and 20 year life expectancies. They are good for several reasons. They seal off bleeding from the femur essentially completely—particularly helpful in high anticoagulation patients. Also, addition of antibiotic cement would be expected to have a lower infection rate, and cases of gross osteopenia can be less likely to have fractures or undesired subsidence.

There are a few basic points which can make a big difference in the quality of hip stem cementation. These points are: (1) After ordinary broaching, loose, mechanically incompetent bone needs to be removed. This is well done with canal brushes and large angled curettes. (2) The canal must be plugged distally a centimeter or two beyond the tip of the femoral prosthesis. (3) The femoral cavity needs to be as dry as possible at the time of cement introduction. This is one of the more difficult tasks to achieve perfectly. First is pulse lavage with an intramedullary nozzle. Next, I use epinephrine soaked sponges pulled completely out to length and introduced to fill the cavity completely—filling retrograde and packing tightly. Shortly before the cement is to be introduced, the epi sponges are changed to dry ones with the same type of firm, retrograde filling. The canal is commonly dried twice occasionally three times.

Cement introduction: (1) A cement gun with long intramedullary nozzle is mandatory. (2) The cement must not be too runny, i.e. of too low a viscosity. You will have more trouble maintaining pressurisation with liquid runny cement, and you risk bleeding from the bone into the cement cavity significantly compromising the cementation. (3) The cement must be introduced retrograde with complete filling i.e. no voids, and not running out of cement to inject before the tip of the nozzle has reached the introitus, the entry point to the femoral cavity. Otherwise you wind up pulling out the nozzle itself out, leaving a void. (4) “Pressurisers,” that is, almost all that I have seen, do not really facilitate pressurisation. Once the canal is completely full with cement and the cement is getting stiffer, pressurisation by pushing at the introitus using your thumb over a lap pad creates tremendous pressurisation that can push cement beyond most cement plugs!

Introducing the femoral component: (1) Last, the femoral component is introduced rather slowly so that one maintains constant pressurisation by virtue of the volume displacement as the component goes to its proper level. Ideally the femoral component reaches its proper level just before the cement is really hard. You really can do this as you get the component 0.5 to1.0 cm. from the final level and impact it slowly as the cement comes to nearly complete hardness.

The two worst things you can do— 1.

Have the prosthesis reach its desired level with the cement relatively runny and have the bone bleed into the cement and degrade the quality of the cement interdigitation.

Consistent, optimum cementation of the femoral component is difficult, but achievable and worth it! You have a component with good stress transfer, no undesired proximal stress shielding like some porous implants have; less bleeding from the canal; good 20+ year fixation, etc., etc.

Conservative management of osteoarthritis is boring, boring, boring! After all, we are surgeons. We operate, we cut! We all know that to retain respectability we have to go through the motions of ‘conservative management’, just so that we don't appear too anxious to apply a ‘real’ solution to the problem.

However, the statistics are overwhelming. An estimated 43 million Americans have ‘arthritis’, but only 400,000 are coming forward each year for TKR. That means that in one way or another 42,600,000 are being treated conservatively. Most of those are self treating by self medication, use of external support, but mostly by decreasing their activities to a level where they can tolerate symptoms. They come to us when these measures stop working.

We know what to do. 1. Weight loss – patients don't do it, 2. Physical therapy – very limited effectiveness 3. NSAIDS – patients have already tried OTC NSAIDS and have heard scary stories about therapeutic NSAIDS, 4. Hyaluronans – expensive, labour intensive, modest effectiveness, 5. Glucosamine/Chondroitin – might work, won't hurt, mixed evidence, 6. SAM-e, MSM – limited evidence – who knows?

What's on the horizon? Could OA of the knee go the way of RA, i.e. dramatically disappear from the population seeking TKR? It could happen. Electrical stimulation – it does good things for chondrocytes, circulation, suppresses destructive enzymes and in controlled studies reduces symptoms and improves function, deferring TKR. Cell therapy – possibly an effective solution to early cartilage lesions in the knee.

I never considered this to be a significant problem if it is noticed. (back to that later)

Aaron Rosenberg's report seems to have agreed, but at the last members' meeting of the Knee Society, Boston, September 2009, others had experience that contradicted my view.

With some experience, ultimately the results were very substantially compromised. This video and presentation show you how to avoid a bad result, actually obtain a perfect result, if you or your student assistant, resident or fellow, bags the MCL.

There are three important points. (1) One needs to recognise the occurrence. (2) The setting is usually varus and so direct end-to-end repair cannot be depended upon. (3) Use of a semitendinosis tenodesis, together with an imperfect, distracted direct repair works perfectly well! (1)

Recognition: The setting is usually varus, but I have had one case in which the chief resident, working with the fellow succeeded in getting the MCL in a valgus knee! In this usually tight varus setting the key feature is that at some point in the case, before component placement, one notices that the exposure is all of a sudden better! Now, the guilty resident or just a passive assisting resident/fellow will usually disagree. The extension space is not so obviously lax, but the flexion space is. Secondly, you do not feel an intact ligament in flexion. And, to prove it I have had to do a little more exposure of the superficial MCL to show the tear. There are at least three mechanisms. Most common is a saw cut. Next is possibly injury with the scalpel or cutting cautery during exposure, and last is damage essentially pre-op by a very sharp medial osteophyte which has thoroughly abraded the ligament.

Laxity in full flexion is not necessarily obvious as the posterior capsular integrity helps hide the instability. Again, the really intact ligament is well felt, and in the situation of laceration, the tibia pulls forward more on the medial side, the medial flexion space opens, and what was usually a tight exposure gets suddenly better.

A presumably key point is not to alter the patient's post-operative regimen! And, to avoid some passive alteration of PT, I advise specifically that the surgeon or those in his/her team do not mention the occurrence to the patient, the family or the PT! I put the whole story in the op-note, and weeks later I will specifically tell the patient what the staple in place is all about.

Introduction

Genu recurvatum is a deformity rarely seen in patients receiving total knee arthroplasty. This deformity is defined as hyperextension of the knee greater than 5°. The incidence of recurvatum has been cited in the literature as less than 1%.