Man-made
Knee joint
Replacement technique
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What is total knee arthroplasty?
Outline of treatment and target patients
Total knee arthroplasty is a treatment method for people who have severe pain and cannot walk due to severe bone osteoarthritis.
It is indicated when medication, medication, or retirement homes are ineffective. In addition, we will make proposals in consideration of problems in daily life.
Material and life of the knee osteoarthritis
Artificial knee joints are made of polyethylene, metal and ceramic. In particular, resin cushioning material, which plays the role of cartilage, wears and damages with daily use and rotation of joints. Depending on the patient's physical condition, activity, weight, etc., until now it was necessary to replace the knee joint with a new one in 10 to 20 years.
The recently developed cushioning material made of ultra-high molecular weight polyethylene, which is resistant to wear, has made it possible to use the same artificial knee joint for a long period of time.
The skill of the doctor in charge also affects how long the artificial joint can be kept in good condition.
This is because different sizes are made in millimeters, and the connoisseur who chooses the most suitable size, thickness, and length for the patient is required. In addition, advanced techniques such as detailed adjustment of the depth and angle of bone cutting and precise observation eyes also greatly affect the service life.
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The parts consist of special alloy femur and tibial parts, special plastic artificial cartilage, and patella parts.
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About surgery
Outline and type of surgery
Roughly speaking, total knee arthroplasty is a flow in which the joint surface is trimmed by the thickness of the part to prepare the surface and the artificial joint is installed. It has been carried out all over the world for more than 40 years, and efforts are being made to improve artificial joints and stabilize surgery.
As shown on the right, the types are roughly divided into artificial knee joint partial replacement, which partially replaces either the medial or lateral side, and artificial knee joint total replacement, which replaces the entire knee joint.
■ Partial knee osteoarthritis
Applicable when wear or damage is only on the medial or lateral side of the knee and the rest is healthy. It is an operation to preserve the healthy part and replace only the part.
【Demerit】
It cannot be used for those who have severe leg curvature, ruptured knee ligaments, or poor knee extension / contraction angle.
In other words, the patients who are eligible are limited.
The long-term results are still unclear.
【merit】
Since the thickness and area of bone scraping are small, the burden on the body is light and relatively small surgery is required.
■ Total knee osteoarthritis
It is an operation that can be performed even for patients with severe cartilage and bone wear.
【Features】
It is also suitable for patients with damage to the cruciate ligament.
It is also possible to treat severe O-legs and X-legs straight.
For patients with unstable knees due to rupture of the knee ligament and patients with bent legs, the symptoms can be improved by using special parts.
In addition, since the entire knee is supported by sturdy parts, long-term results are stable.
Approximately 90% of all knee osteoarthritis performed worldwide is said to be total replacement.
Propose the best treatment
We will examine each patient's medical condition, hobbies, occupation, lifestyle, etc., and consider the best treatment method for each patient.
As a result of examination, even when proposing total replacement surgery, we will provide the best treatment with the latest surgical technique that can perform accurate parts installation with as little burden on the body as possible.
Utilizing treatment experience of over 1000 cases
In principle, the director has experience of more than 1000 cases such as revision surgery and difficult surgery such as severe deformity. If you have any concerns or doubts, please do not hesitate to ask. We will carefully explain until you are satisfied and relieved.
Overview of surgery and changes due to surgery
● Implement preoperative planning
An X-ray examination is performed, and an artificial knee joint that matches the size and shape of each patient's knee is selected. Consider the position and so on.
● Surgery time
It's about an hour and a half.
Surgery time will be longer in special cases and revisions.
● Wound (range of incision)
It is about 10 cm in front of the knee.
● Anesthesia
Perform both general anesthesia and lower body anesthesia.
Some patients may only have general anesthesia.
● Blood transfusion
90% of patients do not need it.
About 10% of patients who are prone to anemia will be transfused with blood received from the blood center.
● Adhesion of bone and artificial knee joint
Instantly fix with bone cement.
● Intraoperative changes
The knee, which did not stretch even in the anesthetized muscle relaxant state, will be fully stretched during surgery.
● Postoperative changes
The movement and posture of the joints and the balance of the whole body are also improved, and the gait is significantly improved.
Postoperative precautions
The most important thing to watch out for in your daily life is a fall.
As you can see in the picture below, you may have a hard time with your own knee joint instead of the artificial knee joint.
Also, even if the accuracy of the knee osteoarthritis is improved, it does not mean that it will be permanently dealt with.
The strength and durability of artificial joints does not reach that of a healthy person's knee.
Looseness between the knee osteoarthritis and your own bone
Cushion material wears out, acting as cartilage
Such a situation can occur.
It is essential that you visit the outpatient clinic regularly even after you are discharged to check if there are any changes or abnormalities in your knees. If any defects are found, reoperation will be required.
Maintain proper weight
Avoid carrying heavy objects
Use handrails for stairs
Do not do high-impact exercise (running, jumping, etc.)
Don't fall
It is important to keep in mind such things in daily life.
Total knee arthroplasty is a treatment that will last a lifetime with the total knee arthroplasty.
We strongly recommend that you keep in touch with your doctor on a regular basis after you leave the hospital.
Trouble that may occur after surgery
About rehabilitation
Rehabilitation started shortly after surgery
Standing and walking training will start the day after surgery or the day after surgery.
There is no long-term bed rest.
Elderly people may experience significant muscle weakness, bedsores, and dementia after spending a lot of time in bed. However, early walking training will help prevent the complications mentioned above.
The general flow until discharge is as shown in the table below.
The above is just a guide.
Some physically fit patients are discharged in about two weeks. If you are elderly and have no physical strength, some people will be discharged after taking more time to rehabilitate.
There are individual differences in the length of hospital stay.
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正座はできますか？種類によりますが、人工膝関節の屈曲角度は最大で120～130度になっています。 120～130度というのは、一般的な日常生活を送るうえで必要な膝関節の角度です。 正座になると膝は150度ほど屈曲します。 つまり人工関節は構造上、正座に対応した設計にはなっていません。 無理に正座をすると、ゆるみや破損が生じる危険性もあります。 健常な方にとっても正座は、膝への負担が過重な好ましくない姿勢です。 ただし実際には写真のように、膝がかなり曲がる患者さんもおられます。 「よく曲がる」からといっても、正座はしない方が良いでしょう。
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自動車を運転したり、自転車に乗ったりしてもいいですか？人工関節そのものに、問題はありません。 タクシーの運転手さんで、仕事に復帰された方もおられます。 いつから乗れるかなど復帰の時期につきましては、個人差があります。 また安全に運転できるかどうかは、ご自身でご判断ください。
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スポーツはできますか？パークゴルフや水泳、ウォーキングなど、足への衝撃が軽いスポーツは行って構わないでしょう。 ハイキングやスキーなどは、もともとのご経験があれば恐らく大丈夫でしょう。 マラソンやエアロビクス、サッカーなど激しいスポーツは推奨しません。 いずれもスポーツの強度や頻度、膝の動きなど、ゆがみや破損が生じないか総合的に判断する必要があります。 開始前に必ず医師にご相談ください。
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MRI検査を受けても大丈夫ですか？人工関節の材質は鉄ではなく、コバルト、クロムを主体とした合金か、セラミックですのでMRIは可能です。
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空港などの検査場で警告のアラームが鳴るのでしょうか？空港などでの検査場では、探知器が反応する可能性があります。 検査員に人工関節が入っていることをご申告ください。 当病院から人工関節が入っていることの証明書をお渡しすることもできます。
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合併症が心配です。合併症につきましては、以下の報告があります。 手術を受ける前に、ご納得いくまで説明を受けるようにしてください。 深部静脈血栓＝エコノミークラス症候群 感染＝１～２％ 人工膝関節のゆるみ、破損 膝の皿（膝蓋骨）の脱臼 二次的な骨折 手術創部周辺の知覚異常 人工材料による生体の異常反応 感染症につきましては、術中はほぼありませんが、術後1～2年で起こることがあります。 歯槽膿漏など身体の別の部位で細菌感染がある場合や、高熱を伴う疾病で血液中に細菌が検出されるケースで、血液を介して人工股関節周囲に細菌が付着してしまうためです。 感染症を予防するために、口腔内は、定期的な歯科検診で健康状態を保つことが大切です。
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手術は何歳くらいまで可能ですか？身体的に問題がなければ80歳台まで、手術が可能と考えられています。 ただし最終的にご自身やご家族が手術可能かどうかにつきましては、心臓や肺などの健康状態を調べたうえで医師の判断を仰いでください。 その他にも、ご旅行や他の病気治療時など、体内に入れた人工膝関節を考慮する必要は、生涯を通じ多くあります。 上記にあります通り、退院後も通院しやすく、受診時に何でも相談できる医師のもとで手術を受けることが重要です。