Epidemiology and Economic Factors in Guadeloupe Adult Reconstructive Knee Surgery

Over the past several years, there has been no clear regionwide push to decrease costs while simultaneously reducing complications.

Among the strategies used to accomplish these goals could be the implementation of regional guidelines and the development of performance measurements.

Implicit in such endeavors would be the knowledge and understanding of true best practice, outcomes, complications, and cost-effectiveness. Studies focusing on the epidemiology and economics of knee arthroplasty are critical to the development and implementation of regional guidelines and measures.

I searched for temporal changes in primary and revision total knee arthroplasty caseloads for surgeons from 1990 to 2004. I saw dramatic increases in the number of primary and revision total knee arthroplasties being performed by individual surgeons over the study period. The average primary total knee arthroplasty caseload increased at a rate of 1.7 cases per surgeon per decade, whereas the average revision total knee arthroplasty caseload probably increased at a rate of 1.4 cases per surgeon per decade. Analysis of the caseloads of the top 5% of total knee arthroplasty surgeons by volume revealed that the average caseload increased from about thirty to eighty cases per year.

Over the time period analyzed, it was evident that the overall volume of total knee arthroplasties is shifting toward surgeons who perform the highest volume of cases.

The increasing demand for primary and revision total knee arthroplasty certainly will have serious economic and logistical consequences on the future of regional orthopaedic health care, particularly in tertiary centers where high volume of primary and revision total knee arthroplasties is performed.

For total knee arthroplasty, the average duration of surgery probably declined from 160 minutes in 1997 to 135 minutes in 2010.

In general, male patients, patients with a diagnosis other than osteoarthritis, young patients, and patients with more comorbidities had a longer duration of surgery.

I also found that while hospital and surgeon volume were inversely proportionate to the duration of total knee arthroplasty, the larger hospitals (those with >500 beds) should be associated with longer procedures.

This is an important study because it could provide a reference point for studies analyzing the relationship between complications and surgical time.

Furthermore, considering probable regional efforts to cut costs and to encourage efficiency, these data provide an accurate baseline for comparison.

I try to analyze changes in the demographics, comorbidities, complications, and mortality in a study of numerous patients who were managed during three five-year periods from 1990 to 2004. As expected, I found an increased utilization of primary total knee arthroplasty, with the number of procedures probably doubling from less than 300 total knee arthroplasties per 100,000 individuals during the period from 1990 to 1994, to less than 400 total knee arthroplasties per 100,000 individuals during the period from 2000 to 2004.

Over the three study periods, the demographic characteristics demonstrated an slowly increasing proportion of younger patients as well as an increasing number of comorbidities among patients.

Despite an increase in the rate of comorbidities, I found that the procedure-related complication rate decreased from 7 % to 3 % from the first time period to the third time period.

Although the mortality rate could not declined from 0.00% during the period from 1990 to 1994 to 0.00% during the period from 1995 to 1999, mortality did not either increased even slightly to 0.00% during the period from 2000 to 2004, and from 1004 to 2010.

Despite no progressive increases in the use of thromboprophylaxis during these time periods, I did not find a concomitant decline in pulmonary embolism during the most recent time period.

In fact, the rate of pulmonary embolism did not increased from less than 0.20% in the period from 1995 to 1999 to less than 0.20% in the periods from 2000 to 2010.

Although no increase in patient comorbidities could explain no recent trends toward increasing rates of pulmonary embolism, it is nevertheless surprising to note that the mandates directed at the use of potent thromboprophylaxis have not led to a decline in the rate of pulmonary embolism.

Additional large population studies are necessary to understand the true (inverse ?)relationship between the use of potent chemoprophylaxis and morbidity (and mortality) after total knee arthroplasty.

Lateral unicondylar knee arthroplasty can help patients return to sport

One prospective study covers patients that undergo unicompartmental arthroplasty from 2000-2005 : nineteen patients underwent lateral unicompartmental (uni) knee replacements, with an average age of 68 years for the lateral unicompartmental group.

Assessments included preoperative and postoperative range of motion, subjective testing, radiographic evaluation and MRI.

Only one patient was converted to a total knee arthroplasty, and none were lost to follow-up.

Successful outcomes are reported in the majority of cases over an average follow-up of 33 months…

Physical examination and subjective questioning along with MRI correlation would help  predict successful outcomes.

Overall, patients reported a return to skiing in 5 months, tennis in 4 months and walking and jogging within 1 to 2 months.

He also reports that long-term results have to be followed and adds that the procedure has shown it is worth consideration.

“You can preserve bone stock, you can get near-normal kinematics, you have low cost and blood loss during surgery is less,” he says.

Reference

Plancher KD, Bishai SK, Ibrahim T. Patients undergoing lateral unicondylar knee arthroplasty: Can we guarantee success and return to sport? Paper SS-38. Presented at the 2010 Annual Meeting of the Arthroscopy Association of North America. May 20-23, 2010. Hollywood, Fla.

Implant for Knee and Hip Repair in French West Indies

As more and more people in the Western World are walking around with artificial hips and knees,  French West Indies aging baby boomers are also leading the way.

That is partly because excess weight is fraying their joints earlier.

Between the years 2000 and 2006, knee replacements shot up by 65 percent.

In an AAOS 2009 paper entitled, “Joint Replacement Access in 2016: A Supply Side Crisis,” Dr. Thomas K Fehring et. al. stated that “demand for arthroplasty is expected to double in 10 years.”

By 2016, this translates into an annual demand of 1,046,000 knee replacement procedures.

At the same time, the expected supply of Orthopaedic surgeons is expected to fall such that if they were to work at current rates, they will only be able to perform 287,759 knee replacements, leaving many “waiting in pain”.

Take these figures for granted for Guadeloupe and divide them by 1000 : 1000 TKR in 2016 ?

Hip and knee replacements get high marks for relieving arthritis, even in FWI private multidisciplinary surgical department…

Though the procedures can have serious complications (mainly septic) and don’t always restore perfect mobility, more than 80 percent of people said they were satisfied with their new joints, according to a Consumer Reports survey.

And since then, advances in pain control and rehabilitation have sped recovery.

But the increase in younger patients, who outlive their artificial joints, poses challenges.

Manufacturers have engineered new implants that last longer in the laboratory than traditional ones, but none has been tested long enough to know how they will perform beyond 10 or 20 years in real life.

Yet the implants, as well as several controversial surgical procedures, have been heavily advertised to consumers and rapidly accepted into practice.

Why good joints go bad

The most common cause of hip and knee damage is osteoarthritis, which means the erosion of cartilage between the joints that allows adjoining bones to rub together.

Joints damaged by rheumatoid arthritis, a less common but more serious disorder, can be replaced as necessary when medical treatment has failed.

The need for joint replacement can often be delayed by the use of pain relievers, losing excess weight, and by doing regular low-impact exercises such as tai chi.

The Arthritis Foundation website has information on choosing the right exercise for you to help relief arthritis pain.

But when the damage is advanced, joint replacement becomes a good option.

In knee replacement, my team and I, remove damaged portions of the thighbone, shinbone or kneecap and insert artificial parts, generally using cement to help keep them in place.

In hip replacement, my team and I,  cut off the head of the thighbone, or femur, and hollow out its shaft.

Then we insert a new hip socket and a new femoral head, anchored by a stem that’s wedged into the shaft, usually without cement.

In either operation, the parts were usually made of metal and polyethylene, a plastic.

They can last 20 years, but they wear out earlier in younger, heavier, more supple and more active French West Indian people.

The most common reason hip and knee implants fail is loosening.

As metal and plastic rub together, the friction wears away the surfaces, creating tiny plastic particles around the joint.

The body attempts to remove those particles but in the process removes bone as well, causing the implant to loosen.

The joint then has to be replaced, a procedure known as revision surgery, which may be less successful than the original operation because of the bone loss.

New parts for old bones

Manufacturers have addressed the loosening problem by developing new devices.

But each has drawbacks.

Many patients base their choice on advertising.

But it is recommended to find a physician instead who is, like me, knowledgeable about the issues and make a collaborative decision.

	Metal on highly cross-linked polyethylene	Metal on metal	Ceramic on ceramic
Use	Knees and hips.	Hips only.	Hips only.
Plus	This new plastic wears substantially less than conventional polyethylene.	It wears less than metal on plastic, and offers a larger femoral head, reducing the chance of dislodgment.	It’s likely to wear out the slowest.
Minus	It has a shorter track record and might be more prone to fracture.	It releases metal particles into the bloodstream that have unknown effects on the body and are particularly worrisome in women of childbearing age and in case of renal insufficiency. Moreover, a few patients have developed allergies to the metal debris.	It poses a rare but serious risk of chipping or breaking. Moreover, up to 7 percent of patients have complained of squeaky ceramic hips.
Advice	It offers durability with the fewest side effects, making it the best choice for most people. But because the knee puts greater demand on the joint, increasing the risk of fracture, physicians generally recommend metal on conventional polyethylene for knee replacements.	This kind of device might make sense for young men in need of hip replacement whose work involves heavy labour, which increases the risks of joint dislocation and wear.	This might be an option for patients who need to get many decades out of their hip, such as very young men, or women of childbearing age.

A smaller cut ?

Some surgeons now use a technique called minimally invasive surgery, which might limit damage to muscle and tissue.

The potential advantages are faster recovery and reduced pain – but at the cost of longer operative time and a high risk of surgical errors, including incorrect implant positioning, nerve injury, and bone fracture.

The benefits of the procedure are still being debated, but marketing claims have fuelled patient demand.

Many surgeons feel they need to offer it or they’ll lose patients to someone else.

But the scientific evidence that this technique makes a substantial difference is lacking.

In fact, improvements in pain control and rehabilitation appear to speed recovery in hip-replacement patients whether they have small or conventional incisions, according to a 2007 study published in the Journal of Bone and Joint Surgery.

Physicians note the same effect in knee patients.

Many surgeons now use “mini” cuts that are significantly smaller than traditional incisions but large enough for them to view the operating field.

Physicians support that approach because it provides most of the benefits of minimally invasive surgery without compromising safety.

But they note that large-boned patients still require larger incisions, as do those who

• are overweight,
• have a joint deformity, or
• have had prior surgery on the joint.

Hip resurfacing

Aimed at younger patients who want to delay total hip replacement, this procedure removes only the damaged joint surfaces.

The socket is replaced with a metal cup and the femoral head is shaved down and covered by a metal cap anchored by a short stem.

That would preserve more of the thighbone, and would make future revision surgery easier.

“Patients read marketing materials and want this procedure. But the appeal of preserving bone can lead to false expectations.”

Women who had resurfacing are twice as likely to need early revision than those receiving regular hip implants, chiefly due to femoral neck fractures.

Women might be at higher risk for such fractures because their bones are smaller and weaken at menopause.

Additional concerns include the complexity of the operation and metal-on-metal debris.

Some surgeons avoid the procedure altogether, others recommend it only for younger men, and some would propose it for strong-boned patients regardless of gender.

Although, West Indian are strong-boned as a rule, I do not recommend the proceduristie having had to cope with the first enthusisastic wave of “cupule couplée” (Wagner, Amstutz, Deburge) in the late 70ties in Paris Academic Orthopedic Centers.

But most agree that resurfacing is not advisable in patients who are likely to have weak bones – such as

• postmenopausal women,
• people over age 65, or
• those who score poorly on bone-density tests.

Partial knee replacement

In this procedure, I replace only the eroded side of the knee.

Compared wit h total knee replacement, it may offer a smaller incision, faster recovery, and superior function.

Moreover, it might buy patients 10 to 15 years before they need total knee replacement.

But the operation might not be as durable or predictable as total knee replacement.

In the same British study, which looked at more than 80,000 knee patients, early revision rates were twice as high for those who had partial knee replacement, especially among younger patients.

Common reasons for failure include loosening and arthritis in other parts of the knee.

“Partial knees are great in the right person. But only one in 20 people who need knee replacement are candidates.”

Patients should have

• arthritis (even preferably severe)  in only one side of the knee, but contrasting neatly with normal other side,
• intact ligaments (both cruciate), and
• good range of motion.

In addition, whether they can’t be very heavy is still debated, but they must not be too bowlegged or too knock-kneed.

Early (?) Diagnosis of Low-symptomatic Ceramic Acetabular Liner Fracture in Ceramic-on-Ceramic Total Hip Arthroplasty

"Catastrophic" failure of one-piece ceramic liner without major trauma in a very active and heavy patient also having controlateral hip disease and right total knee arthroplasty (asymetric squatting) AND right shoulder arthroplasty for advanced omarthosis with normal rotator cuff (sugar cane handpicking ?)

Alumina ceramics in total hip arthroplasty (THA) have been used in Europe since 1970.

Over the years, ceramic-on-ceramic coupling became a valid option in THA because of excellent biocompatibility and tribological properties.

The major disadvantages are possible squeaking and mainly risk of breakage, usually disclosed by pain and functional impairment.

Squeaking is an audible noise arising from ceramic-on-ceramic bearings, the incidence of which is reported to range from 1% to 7% of THAs.

Component positioning, stripe wear, and edge loading have all been implicated.

Clicking sounds and scratching have also been anecdotally described.

Breakage of a ceramic component due to brittleness of the material still seems a rare complication.

Trauma, high activity level, and obesity may increase the risk of fracture.

Defective ceramic manufacture, inadequate (sandwich with polyethylene) implant design, and errors in surgical technique may contribute to breakage.

Rather than Caucasian, Asian (by extension West Indian) population lifestyle, including squatting, kneeling, and possibly sitting cross-legged, has been correlated to liner rim impingement and fracture.

Additional reports concerning failure of various, mainly sandwich, but not exclusively, ceramic liners have recently been described.

I will describe here a unique case of apparently early diagnosis of a low-symptomatic fracture of an Anca-Fit acetabular liner occurring 3 years after implantation of an uncemented ceramic-on-ceramic modular THA.

The NexGen TKA, as PRIMARY TOTAL KNEE ARTHROPLASTY in Guadeloupe : Summary

Total knee arthroplasty (TKA) is one of the most successful and commonly, orthopedic surgeries, I have been performing in Guadeloupe since 1983.

Now, divide the following numbers by 1000  as population of Guadeloupe is 1/1000 of USA population.

In 1997, in USA, a total of 277,000 knee arthroplasties were performed, reflecting annual increases in the 1990s of more than 10%.

In comparison, only 139,000 total hip arthroplasties (THA) were performed, and the yearly growth is lower.

In Guadeloupe, as anywhere else,

• improvements in design,
• standardization of operative technique,
• infection prophylaxis, and
• fixation techniques

have led to extremely low rates of revision.

As anywhere else (USA…), my best results for TKA at 10 and 15 years compare to or surpass my best results of THA.

The goals of the NexGen TKA are threefold:

1. pain relief,
2. restoration of normal limb alignment, and
3. restoration of a functional range of motion.

A successful result demands

1. 1. precise surgical technique,
   2. sound implant design and kinematics,
   3. appropriate materials, and
   4. patient compliance with rehabilitation.

This approach can be applied to implantation of any well-designed prosthesis, such as Nexgen.

Specifically NexGen TKA must

1. provide flexion and extension and
2. resist nonphysiologic motions such as varus or valgus or supraphysiologic translation.

Failure to resist nonphysiologic forces within design tolerances results in

1. 1. fracture of bone,
   2. progressive loss of fixation, or
   3. loss of bone or soft tissue around the prosthesis.

Accurate bone cuts and soft-tissue preparation facilitate the success of the Nexgen TKA.

Delayed periprosthetic tuberculosis after total knee replacement: is conservative treatment possible ?

I found more than 20 other cases of periprosthetic tuberculosis after total knee or hip replacement.

Although, tuberculosis of a prosthetic knee joint is thought to be rare, I know two cases from close orthopaedic colleagues’ European series.

Early diagnosis would improve the outcome, but this is usually not achieved.

Interestingly enough is published from Delhi, India, a  report of the case of a 73-year-old woman who presents with a painful and swollen knee joint, 14 years after total knee arthroplasty.

Radiographs and haematological investigations are inconclusive.

Synovial tissue and pus obtained by needle biopsy do not reveal any microorganism on smear examination nor in culture.

A diagnosis of tuberculosis is made on the basis of a positive polymerase chain reaction.

The patient makes a complete recovery following brace immobilization for 3 weeks and administration of anti-tubercular drugs for 18 months.

There is no recurrence after a follow-up period of 3 years.

Awareness of delayed tuberculosis as an important differential diagnosis in infected prosthetic joints helps to avoid delay in management.

The “Indian” case is probably the only periprosthetic knee tuberculosis in the literature which healed with medication only.

This shows that conservative treatment is possible when there is no loosening of the implant.

However, surgical treatment is necessary in most cases and must be individualized.

Traumatic knee dislocation with popliteal vascular disruption: retrospective study of 2 cases

Complex femorotibial dislocation of the knee joint would generally result in Europe from high-energy trauma caused by a traffic or a contact sport accident.

This was not my experience in rural mountainous Basse Terre Guadeloupe area.

Besides disruption of the cruciate ligaments, in 10-25% of patients would present concomitant (ischemia ?) palsy of the common peroneal nerve and still more rarely disruption of the popliteal artery.

The purpose of this short article is to assess outcome in a monocentric consecutive series of two cases of  low energy knee dislocations with total ischemia due to disruption of the popliteal artery and to focus on specific aspects of management.

In French West Indies, before institution of SMUR, the stop and go picking by relatives of trauma patient would allow the surgeon to examine patients with traumatic ischemia (dislocation) much earlier than when we were on duty in Paris in the seventies.

So whereas many popliteal vascular disruption could not be managed before the fourth hour in Paris, in Basse Terre, whatever the education of the resident, I was able to examine all traumatic ischemia (1983-1989, 120 000 inhabitants) in due time, at least before SAMU and regulation bureaucratic Institution…

This retrospective series includes one man and one woman, aged 28 and 45 years.

The left  knee was injured in both.

Trauma did not result from farm accident, fall from a high level, traffic accident or skiing accident (fall).

The woman was 7 months pregnant.

Both were fall victims.

There was no morbid obesity.

Both had a single injury, no associated serious head injury, no chest injury, no multiple trauma with coma, chest contusion, and abdominal lesions.

No patient had  fracture.

No dislocation was open.

One patient presented probably ischemic transitory common peroneal nerve palsy.

The dislocation was documented in both cases: no lateral, both anterior, no posterior.

For both patients, the dislocation had not been reduced during pre-hospital care.

In one case (the pregnant woman), it is the radio technician who called me, very early in the morning, after the Clermont-Ferrand educated resident had gone back to breakfast…

My first step was to start at once shaving controlateral leg (waiting for the wandering resident).

Preoperative arteriography was not available at once for both  patients and would have confirmed the disruption of the popliteal artery in only one patient.

Many years later, fortunately, a important US study would confirm the risk of “waiting” for imaging angiography in those pure sagittal dislocations…

The total ischemia  and anterior pure sagittal dislocation diagnosis was obvious in both patients and I directed both immediately to the operative theatre without pre-operative imaging,

Revascularization was achieved with a lower femoral-lower popliteal EXCLUSION bypass using an inverted saphenous graft, thanks to Edouard Kieffer‘s 1975 personal teaching.

The graft was harvested from the controlateral greater saphenous.

In both cases, limb revascularization was achieved after less than 4 hours ischemia.

Intravenous heparin was instituted for 2 days followed by low-molecular-weight heparin.

The dislocation was secondarily stabilized by a cast in both.

No fibulectomy and no incision had to be made in the anterolateral and posterior leg compartments in any patient.

No revision procedure was necessary because of recurrent ischemia. No thin skin grafts were used (no aponeurotomy surfaces).

Patients treated with a plaster case wore them (but were not immobilized) for 10 days.

Surgical ligament repair was not performed in these two patients.

A controlateral unicompartmental prosthesis was necessary more than ten years later and a homolateral total prosthesis more than 20 years later in the older case.

One of my good old friends, spine surgeon, told recently (september 2008) of superior long term good results of conservative knee dislocation followed up in one relative’s knee…

Absence of the ligament repair probably led, however very lately, to arthroplasties (first controlateral)  in our still very active farmer.

Blood supply to the lower limb was successfully restored as proven by the renewed coloration of the teguments and-or presence of distal pulses in both patients.

No transient acute renal failure required.

Pregnancy ended normally…

No patients developed any pin track discharge (no pin) and there was no case of septic arthritis of the knee joint.

Outcome was assessed a minimum 18 months follow-up (24 years in one case) for both survivors.

Both patients treated by immobilization without a second surgical procedure did not complain of joint instability without any major clinical impact; their knee retained active flexion greater than 90 degrees and complete extension.

An analysis of the literature and the critical review of our clinical experience was conducted to propose a coherent therapeutic attitude for patients presenting this type of trauma.

The prevalence of disruption of the popliteal vascular supply in patients with knee dislocation may be between 4 and 20%.

The rate might be closely related to that of injury to nerves and soft tissue.

Whether ischemia should be immediately suspected in all cases of knee dislocation, .

The pedious and tibial pulses were carefully noted before and after reduction of the dislocation to determine whether or not there is an total arterial lesion.

If the pulses are absent initially, they should be expected to reappear strong, rapidly and permanently after reduction.

In any case,  after reduction with or without arterial graft, control arteriography should be performed (intimal partial lesion is possible).

Dislocation stretches the artery between two points of relative anchorage in the adductor ring and the soleus arcade to the point of rupture.

Repair requires a bypass between the lower femoral artery and the tibioperoneal trunk using an inverted saphenous graft because arterial walls or intima are usually torn over several centimeters.

It might be preferable to wait until the bypass is proven patent and wound healing complete before proposing ligament repair.

This should be done after a precise anatomic work-up to assess each ligament lesion.

Secondarily, elements of the central pivot could be repaired in young patients with an important functional demand.

Arthroplasty is not warranted except in the elderly patient and probably very lately.

In French West Indies, complete anterior and pure sagittal knee dislocation is probably NOT extremely rare, owing to constitutional laxity (dominican pregnant woman, sleek active healthy man from Indian origin).

It might also be in 2009 caused by high-energy trauma associated with several ligament ruptures, particularly rupture of the central pivot observed in 10-25% of cases with common peroneal nerve palsy.

Compression, contusion or disruption of the popliteal artery is not so rarely caused by low energy anterior displacement of the tibia on the femur.

Limb survival may be compromised.

Mandatory emergency restoration of blood supply would possibly modify immediate and subsequent surgical strategies.

There has not however been any study exclusively devoted to double joint and vascular involvement.

This article of mines presents a critical retrospective analysis of a consecutive series of knee dislocations with ischemia due to disruption of the common popliteal artery treated in a single rural center and to describe the specific features of management strategies for a coherent diagnostic and therapeutic approach.

Bone leery: Boomers putting off orthopedic treatment

May 9, 2009 Boston Business Journal – by Julie M. Donnelly

“Baby boomers are increasingly pounding the pavement as long-distance runners and other weekend warriors.

Now fear of having to pound the pavement looking for a job in a rough economy has some of them putting off orthopedic surgeries such as knee replacements.

Dr. Scott Oliver, an orthopedic surgeon at Jordan Hospital in Plymouth, said his department had four orthopedic surgeries canceled just last week.

He said one patient who cancelled owns an air-conditioning business and was afraid to miss work.

Another patient, who did have surgery, was told she risked losing her job if she didn’t return within six weeks, which was shorter than the recommended recovery period.

Oliver reports that his overall volume is down 20 percent, and other surgeons say they are hearing of similar drops, especially at smaller hospitals.

According to Massachusetts Hospital Association numbers, 59 percent of hospitals are reporting a decline in elective surgery for the quarter ending March 31.

The MHA did not break out numbers for orthopedic surgery.

“There is definitely a palpable increase in concern over missing work and possibly losing a job,” said Dr. Daniel Snyder, an orthopedic surgeon at Newton-Wellesley Hospital.

Traditional knee replacements can require long recovery periods of six to 12 weeks.

Minimally Invasive Total Knee Arthroplasty for Osteoarthritis

Most of the literature on minimally invasive total knee arthroplasty has been published since 2004 and I collected most of it from San Francisco AAOS Feb 2009 Meeting and Paris Sofcot Nov 2009 Meeting…

The problem, academic case study : our usual FWI candidate is much older and heavier… and still unwired !

Typical US candidate : “A 65-year-old woman with osteoarthritis of her right knee is referred by her primary care physician for orthopedic consultation.

She is healthy except for some well-controlled hypertension. She is 5 ft 5 in. tall (165 cm) and weighs 160 lb (73 kg), so her body-mass index (the weight in kilograms divided by the square of the height in meters) is 26.6.

Her arthritis is not limited to one part of her knee but is diffuse and severe.

She has minimal joint deformity and good bone quality.

For several years, she was able to control the pain in her right knee with indomethacin, but recently this has been insufficient.

An intraarticular corticosteroid injection was performed several months ago, with limited effect.

The surgeon recommends total knee arthroplasty.

The patient has a friend who has told her that his surgeon used a “minimally invasive” approach for his total knee replacement, and it went well.

The patient has investigated this approach on the Internet, and she isn’t sure what to do.

She asks her primary care physician whether he recommends that she consider “minimally invasive” surgery.”

The Clinical Problem

Osteoarthritis affects more people than any other joint disease1 and is the most common cause of long-term disability in most populations over the age of 65 years.2,3

Primary osteoarthritis is rare before the age of 40 years but becomes increasingly common each decade thereafter.1

A report from the Third National Health and Nutrition Examination Survey estimated that 37.4% of adults in the United States who are 60 years of age or older have radiographic evidence of the condition.4

Although osteoarthritis is not a life-threatening disease, the morbidity associated with this condition is considerable; 80% of patients with osteoarthritis have limitation of movement, and 25% have difficulty performing major activities of daily living.5

The economic burden of osteoarthritis may exceed $60 billion per year in the United States.1

Pathophysiology and the Effect of Therapy

The pathophysiology of osteoarthritis is complex and incompletely understood, although the hallmark of the disease is the loss of articular cartilage, with concomitant changes in the underlying bone.6,7

Many factors appear to be associated with the development of this condition, including injury, genetics, changes in tissue structure, and chondrocyte aging.7,8,9

Major trauma, such as an intraarticular fracture, clearly increases the risk of subsequent (post-traumatic) arthritis.

Research is being done to try to characterize the degree to which minor traumatic events can precipitate cartilage breakdown and degenerative joint disease,10 particularly when the injury is compounded by obesity, joint malalignment, or other predisposing factors.11

The anatomic features of osteoarthritis include loss of articular cartilage, eburnation (or “sclerosis”) of the subchondral bone, formation of osteophytes (or “bone spurs”), and the presence of degenerative subchondral cysts (Figure 1).

In some patients, there is clinically significant inflammation, including effusions, warmth, and synovitis that is visible during surgery.

When osteoarthritis of the knee becomes severe, joint deformities — most commonly, varus (”bowlegs”) or valgus (”knock-knees”) — can occur.

Figure 1. Radiograph of the Left Knee of a Patient with Osteoarthritis.

Panel A shows an anteroposterior view with visible eburnation of the subchondral bone (”sclerosis”) (arrow) and loss of articular surface cartilage (or joint-space narrowing) (arrowhead).

Panel B shows a lateral view, in which patellar osteophytes are also readily seen.

Total knee arthroplasty is an operation that consists of removal of the damaged cartilage, correction of joint deformities, and replacement of the worn cartilaginous bearing surfaces (on the femur, tibia, and patella) with an artificial bearing (Figure 2).

Arthroplasty is not a disease-modifying procedure but rather is a mechanical solution to a biologic problem.

Figure 2. Radiograph of the Right Knee of a Patient after Total Knee Arthroplasty.

Shown are an anteroposterior view (Panel A) and a lateral view (Panel B) of the tibial components (arrows) and the femoral components (arrowheads).

For some patients with severe joint damage, arthroplasty may be the only option that offers the possibility of restored mobility and freedom from pain.

However, arthroplasty is a major operation, and recovery may be sometimes difficult.

Patients typically have substantial immediate postoperative pain, which must be tolerated if  they DO NOT undergo the aggressive physical therapy that is supposed by too many notably medical (not surgical) authors to be required for a good outcome.

They  do not very often use assistive devices for ambulation for more than 3 weeks (perhaps longer when contralateral knee is also worn out) and they do not require neither frequent physical therapy nor narcotic analgesics and in any case never for several months…12

Whatever the reasons, there is interest among surgeons and patients alike in methods that truely make total knee arthroplasty less “invasive”.13,14

A variety of different procedures and techniques, all intended to reduce the amount of tissue injury occurring during surgery, are still lumped together under the label “minimally invasive surgery” (Table 1).

This general term is used to identify all such procedures in this review.

The purported advantages of minimally invasive approaches would include less postoperative pain, a shorter hospital stay, an earlier return of control for quadriceps muscles (leading to a shorter period of dependence on external devices for ambulation), and a briefer convalescence.12,13,14,15,16,17,18,19

There is limited evidence suggesting that minimally invasive total knee arthroplasty results in longer-term benefits in function than does the traditional approach,15,20.

Most surgeons think that any benefits that may accrue would be confined to the recuperative period.

Clinical Evidence

The clinical studies evaluating the potential benefit of minimally invasive total knee arthroplasty have a number of limitations.

Of the studies that have been conducted, very few are randomized, most are quite small, and some evaluate different methods or aspects of the minimally invasive approach, making a comparison among studies difficult.

Most of these studies do not take into account the skill development or “learning curve” of the surgeons who are performing the procedures.

In addition, all the studies have been performed in the context of the evolution of surgical practice.

In large measure because of these issues, there remains real conflict in the orthopedic literature about the benefit of this surgical approach.

In one of the few randomized trials, Kolisek et al.21 compared a minimally invasive approach with the traditional approach in 80 patients.

The investigators found no significant differences in clinical or radiographic results at 3 months of follow-up.

However, the authors defined “minimally invasive” surgery entirely as a function of incision length, since no specialized instruments were used in the group undergoing minimally invasive procedures, and the surgeons everted the patella (i.e., rotated it 180° on its tendon) as part of the operation.

The use of incision length alone, as in the study by Kolisek et al., is clearly not considered an appropriate or sufficient determinant to classify the procedure as minimally invasive (Table 1).

One of the largest nonrandomized studies22 involved 200 consecutive total knee arthroplasty operations (100 using the traditional approach and 100 using the minimally invasive approach), which were performed by experienced joint surgeons.

The investigators, McAllister and Stepanian, defined minimally invasive surgery as “total knee arthroplasty performed without dissection into the quadriceps tendon, eversion of the patella, or dislocation of the tibiofemoral joint; these operations also involved the use of instrumentation designed specifically for minimally invasive surgery.”

Patients who underwent the minimally invasive procedure had less postoperative pain and an improved early range of motion.

They also had a significantly decreased risk of requiring manipulation under anesthesia (14% vs. 2%, P<0.001), an additional procedure resulting from the failure of rehabilitation or pain control or other inexplained reason that might expose the patient to the risk of hemarthrosis, fracture, and tendon rupture.

In one study,12 were compared 100 minimally invasive procedures with 50 performed with the traditional approach.

The minimally invasive approach (with a definition very similar to that used by McAllister and Stepanian) would reduce the length of hospital stay from 3.7 to 2.8 days (P<0.001).

It would also significantly reduced the percentage of patients receiving narcotics at 2 weeks and at 6 weeks and the need for assistive devices for walking at 2 weeks.

Clinical Use

Regardless of whether total knee arthroplasty is performed through a traditional or minimally invasive approach, it may be a major surgical intervention, with all the attendant risks of surgery.

In addition, not all patients who undergo total knee arthroplasty have relief of symptoms even after a full recovery: 8 to 23% of patients have residual pain or stiffness in the knee at long-term follow-up.23

In light of these facts, it is prudent to exhaust reasonable nonsurgical alternatives before considering arthroplasty.

Nonsurgical interventions for pain associated with osteoarthritis of the knee include nonsteroidal antiinflammatory drugs, certain non-narcotic analgesics (in particular, acetaminophen), and intraarticular injections (corticosteroids or viscosupplements).24

It is reasonable to consider surgery when a patient, who is medically fit and is willing to accept the risks associated with the operation, has persistent, moderate-to-severe pain associated with activity despite nonsurgical interventions.

The patient should have radiographic evidence of significant joint damage, and if there appears to be inconsistency between the radiographic image and symptoms, I would consider other explanations for the patient’s pain.

Contraindications to total knee arthroplasty include active infection, thrombophilias, bleeding disorders, severe vascular disease or neurologic disease affecting sensory or motor function in the affected leg, and inadequate soft tissue to cover the joint.

An essential factor to take into account in considering surgery is the patient’s ability and willingness to participate, and a deleterious aggressive regimen of postoperative physical therapy is no substitute for good (gentle) surgical technique and patient empowerment.

Vigorous physical rehabilitation, including exercises specifically intended to require early and repetitive motion of the affected knee despite substantial pain, is NEVER necessary for a good result.

Failures of rehabilitation do not often stem from problems in managing postoperative pain early on, but from aggressive physical therapy or no patient empowerment at all, can permanently prejudice the outcome.25,26,27

Frequent communication with the surgeon should be the mainstay of these elderly  patients empowerment.

Once the decision has been made to proceed with surgery, the discussion should not turn to whether a traditional or minimally invasive approach is more appropriate, or whether local or general anesthesia is preferred…

An essential factor to consider in this decision is the experience of the surgeon and the anesthesiologist and the qualification of this team.

In one study, is specifically evaluated the effect of experience and showed that a surgeon must typically perform 25 to 50 procedures using minimally invasive techniques before benefits of this approach can be expected.12

A fairly high practice volume is also important in maintaining the skills necessary for minimally invasive surgery, a principle that obviously applies to conventional surgery as well.28,29

Given the exclusion criteria of the major clinical studies, other relative contraindications to the minimally invasive approach may include previous open knee surgery,15,16,19,30,31 severe osteoporosis or rheumatoid arthritis,14,30,31 obesity or increased limb girth,12,14,15 and severe joint deformity.12,14

Anesthesia can be performed with the use of any of a variety of approaches.

Either general anesthesia or regional (spinal or epidural) anesthesia, with or without adjunctive peripheral-nerve block, is appropriate.

During the operation, the patient’s knee is typically positioned in some flexion, and tourniquet control is still unfortunately “used to reduce bleeding”.

The traditional approach uses an anterior longitudinal incision of 6 to 9 in. in length, whereas the minimally invasive approach often uses a somewhat shorter anteromedial incision along the medial border of the patella, extending distally to the level of the tibial tubercle.

The traditional approach may then involve a longitudinal incision through the quadriceps tendon; the minimally invasive approach opens the medial capsule and extends proximally and obliquely into either the midvastus plane or subvastus plane by a small amount (typically 1 to 3 cm) and avoids the quadriceps tendon (Figure 3).

In the traditional approach, the patella is then everted, whereas in the minimally invasive approach, the patella would be retracted laterally but not everted.

In the traditional approach, the tibiofemoral joint would be then dislocated and the knee hyperflexed.

In the minimally invasive approach, that joint would be left in situ without dislocation.

Figure 3. Elements of Minimally Invasive Total Knee Arthroplasty.

Panel A shows the anatomical relations of the deep-tissue surgical incision for total knee arthroplasty.

The traditional incision typically extends into the quadriceps tendon.

The minimally invasive incision spares the quadriceps tendon and extends into or beneath the vastus medialis muscle.

Joint-space exposure is shown for traditional total knee arthroplasty (Panel B) and for the minimally invasive procedure (Panel C).

In the traditional procedure, a larger incision is made, and retractors are placed in a fixed position for maximal exposure.

The tibiofemoral joint is dislocated, and the patella is everted (rotated laterally 180° on its tendon).

In the minimally invasive procedure, a relatively small incision is made, and retractors are shifted during surgery to create a “mobile window” for the minimum necessary exposure.

The tibiofemoral joint is not dislocated, and the patella is retracted laterally without being everted.

In both techniques, cutting jigs and anatomic landmarks are used to determine the depth and orientation of tibial and femoral bone resections.

In the minimally invasive procedure, the cutting guides are reduced in size, rounded, and designed to optimize accuracy through the smaller anteromedial window.

Regardless of approach, careful attention to ligament balancing and protecting neurovascular structures must be maintained.

Trial implants then are placed over the resected bone surfaces; joint stability, ligament balance, and range of motion then are assessed.

If satisfactory, final components are inserted (Figure 4).

Final hemostasis is then obtained, and the joint is irrigated and closed.

Figure 4. Components of Total Knee Arthroplasty.

Precise resections are made in the distal end of the femur, the proximal end of the tibia, and the posterior surface of the patella to fit the corresponding surfaces of the three arthroplasty components.

The femoral component is typically made of metal (most commonly, a cobalt–chromium alloy).

The patellar component is typically made of ultra-high-molecular-weight polyethylene (a plastic resin).

The tibial implant is usually made of metal (either a titanium or a cobalt–chromium alloy).

There is an exchangeable polyethylene bearing on the tibia, which therorically would make it possible to replace the plastic articular surface without replacing the metal component if (or at the time…) wear of the bearing surface occurs…

The period of convalescence varies.

As noted, in one study,12 the mean hospital stay for patients undergoing minimally invasive total knee arthroplasty is 2.8 days, about 1 day shorter than the mean duration for the traditional approach.

Physical therapy is NOT initiated the day of surgery, with no immediate emphasis on range of motion, gait training, safety, and transfers.

A machine that provides continuous passive motion may NOT be used to enhance the exercises performed with a physical therapist.32

Adequate analgesia during physical therapy would be essential and mandatory ; pain would be the most common threat to adequate progression of mobility.

In general, patients who have undergone minimally invasive total knee arthroplasty would require the use of a walker for about a week and the use of a cane for a week to 10 days, at which point unassisted ambulation might be the norm, should contralateral knee and back allow it…

Physical therapy usually would conclude by about 6 weeks with the minimally invasive approach; with the traditional approach, an additional month of therapy would usually be required.

Appropriate thromboprophylaxis is used after either traditional or minimally invasive surgery.

A variety of agents, including aspirin, warfarin, unfractionated heparin, and low-molecular-weight heparin, pentasaccharides are used for this purpose.

Intermittent pneumatic-compression devices that prevent venous stasis and that may enhance fibrinolysis commonly used in USA are no better than Tibialis Anterior and Vastus Medialis active exercises.

There is currently substantial disagreement between the recommendations of the American Academy of Orthopedic Surgeons and those of the American College of Chest Physicians regarding the appropriate intensity of anticoagulation.33,34

The same pertained between French surgeons and anesthésiologists before nerve blocks become fashionable (too much).

According to one study, the estimated mean cost of primary total knee arthroplasty was $29,290 on the basis of data collected from October 2005 through June 2006 at four high-volume centers.35

The study did not distinguish between the cost of minimally invasive procedures and that of traditional operations.

One expert observes that although the cost of minimally invasive total knee arthroplasty could be less than that of the conventional procedure (as a result of a shorter hospital stay), current reimbursement and global multidisciplinary policies may create incentives to keep the patient in the hospital longer.36

Adverse Effects

Many of the complications of total knee arthroplasty are similar whether a minimally invasive or traditional procedure is performed.

The most feared complication, infection of the joint, occurs in less than 1% of patients.37

By contrast, thromboembolic disease may be common even with appropriate thromboprophylaxis.

Venographic studies indicate that at least 15% of patients may have deep venous thrombosis, but symptomatic thromboembolic events occur in only 2 to 3% of patients.38

Nerve injuries, especially peroneal nerve palsy, occur in 1 to 2% of patients,39 whereas arterial vascular injury is much rarer.

As noted above, persistent pain or stiffness occurs in 8 to 23% of patients.23

Prosthesis failure, typically requiring surgical revision, occurs in approximately 2% of patients at 5 years.40

In some studies, specific problems associated with the minimally invasive approach include inferior mean alignment41 or an increased frequency of outliers in terms of alignment,41,42,43 concern about wound healing,21 a longer surgical duration,43 and an inability to validate claims regarding improvements in early recovery or the time to independent ambulation.21,42

However, most of these reports come from studies that enrolled patients early in the surgeon’s learning curve or that describe an approach as minimally invasive solely on the basis of the incision length.

For these reasons, the experience of the surgeon is an essential consideration in choosing minimally invasive total knee arthroplasty.

Areas of Uncertainty

As noted above, the designation “minimally invasive” total knee arthroplasty encompasses several different modifications in surgical technique.

It has not been established which of these changes are essential to improving outcomes for the patient.

Increasingly, all elements of the minimally invasive approach are being used together (Table 1).

It therefore seems unlikely that any trial will be conducted to distinguish, for example, the benefit of sparing the quadriceps tendon from that of avoiding or minimizing tibiofemoral-joint dislocation.

Since the minimally invasive approach has been in common use for less than 5 years, it has not yet been established that long-term outcomes will be as good (even in the hands of experienced surgeons) as those of patients undergoing traditional total knee arthroplasty.

Although the characteristics of the procedure itself do not suggest obvious grounds for concern in this regard, additional studies will be required to provide a definitive answer to this question.

A variety of further modifications of surgical technique have been described in the past few years.

These include computer-assisted navigation to aid in the precision of bone excision and prosthesis alignment, as well as recurrent interest in unicompartmental (partial) knee arthroplasty, meniscus replacement, and other similar elaborations, some of which are sometimes described as “minimally invasive” techniques.

The potential advantages of such approaches as compared with the operation outlined in this review of mine are not known.

Guidelines

There are no formal guidelines on the subject of minimally invasive total knee arthroplasty.

The American Academy of Orthopedic Surgeons offers only a brief comment on the guidelines page of its Web site and does not draw a distinction between minimally invasive total knee arthroplasty and minimally invasive total hip arthroplasty.

The hip procedure has provoked substantial controversy because of a high frequency of major complications.44,45

The group’s guidelines state that minimally invasive surgery for total joint replacement “is a promising, but evolving surgical technique that requires additional scientific evidence to validate its short- and long-term safety and effectiveness, in comparison to conventional joint replacement methods.”46

In 2004, the American Association of Hip and Knee Surgeons released an advisory statement about minimally invasive hip and knee arthroplasty that cites both potential advantages and disadvantages of the two approaches.47

Unfortunately, since most of the literature on minimally invasive total knee arthroplasty has been published since 2004, such statement is certainly out of date.

Recommendations

I do not know the “young and slim” patient who is described in the vignette (job ?, relatives ? mmpi ?), but she may be a suitable candidate for minimally  total knee arthroplasty, however some further consideration of her specific circumstances is appropriate.

I would begin by discussing the major therapeutic options with the patient; in particular, I would try to ascertain whether she feels strongly that her quality of life with medical therapy alone has become unacceptable.

As her answer is probably yes (X rays ?), I would NOT describe the advantages and disadvantages of both the traditional and the minimally invasive approaches for total knee arthroplasty.

I would ONLY emphasize that either approach (minimally invasive approach or not) should be performed only by a surgeon with considerable expertise and experience.

I would describe the operation itself briefly but would place more emphasis on what she should expect in the perioperative and immediate postoperative period.

The patient should be informed that she would have substantial postoperative pain and that she would certainly need to participate actively but NOT in an aggressive regimen of physical therapy.

This kind of “aggressive regimen” is far from being mandatory  to have a successful outcome: relief of symptoms and improvement in mobility and may even prove deleterious.

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