Osteoarthritis (OA) of the knee joint is mostlyso-called primary OA. Secondary OA due to meniscus injury, tibia plateau fracture, femoral condyle fracture, patella fracture, angular deformity of femur and/or lower leg, rheumatoid arthritis and so on is of relatively low incidence. The‘primary’ OA of the knee joint is frequent in aged people. Because of this, it is attributed to primary senile degeneration of the articular cartilage, but is this correct? If it is, primary OA should be seen equally often in all other joints of the body. But‘primary’ OA occurs predominantly in the knee joint and is associated with a varus deformity of the joint. The pathogenesis of‘primary’ OA should be sought elsewhere.
I think that so-called primary OA of the knee joint is really secondary to neuro-muscular dysfunction. If the muscle strength of the body decreases and reflex control of standing posture attenuates, the body may be apt to fail down. To prevent the falling down, it becomes necessary to stand with the legs open to expand the base area of the body. If a person walks with the legs open, the body sways from side to side. Recently I have analyzed influence of this sway on the knee by a biomechanical method.
The following description concerns a person whose left lower extremity is watched from behind during a half step including a left single support phase and the subsequent double support phase.
(1) When a left single support begins, the left acetabulum is pushed upward by a force (f₁) . The line of action passes left of the center of gravity of the body segment composed of head, arms, trunk and right lower extremity (HATRE) . The HATRE begins to rotate clockwise around the center. Then the center moves upward and also leftward or rightward according to whether the left lower extremity is adducted or abducted. If the gravity center of HATRE, origin and attachment of the hip abductors, abduction angle of the functional axis of the left lower extremity, and the size of (f₁) are known, the force (f₂) of the hip abductors necessary to arrest the rotation of HATRE, vertical shifting force (g₁) and horizontal shifting force (i₁) can be calculated. As the left foot is fixed on the floor f₂also pushes the body to the right.
(2) The body segment HATRE sinks during the single support period (t₁) by the force of gravity. An additional force (f₃) of the left hip abductors is necessary to arrest the gravitational sinking of HATRE. The force f₃can be calculated if the mass (M kg) of HATRE is known. As the left foot is fixed on the floor f₃also pushes the body to the right.
(3) Even if the rotation of HATRE due to f₁, and the sinking of HATRE due to (M kgf) are arrested by f₃the body as a whore will fall to the right during the left single support period (t₁), if the left foot is located left of the perpendicular line through the center of gravity of the whole body. This resembles the motion of an inverted physical pendulum, though the human body is not so rigid as a statue. The angular velocity at the end of ti can be calculated if the moment of inertia around the gravity center of the whole body, the distance between the left foot and the gravity center, and the initial inclination of the line connecting the left foot and the gravity center are known. The revolution of the whole body around the left foot has vertical and horizontal components of momentum. The sum of the horizontal component of the momentum and the impulse of the above described horizontal forces is approximately the total horizontal momentum of the whole body moving to the right. The horizontal momentum must be checked by the force f₄of the right hip abductors in a very short duration of double support phase, otherwise the whole body must actually fall to the right.

View full abstract

In 1968, Ahlback et al. became aware of a peculiar form of aseptic necrosis occurring principally among older patients. The spontaneous osteonecrosis of the knee occurs mainly on the medial femoral condyle and shows by x-ray radiolucency with a surrounding sclerotic border which gradually increases into osteoarthritis of the knee.
We have experienced thirty cases of spontaneous osteonecrosis of the knee. Of these thirty cases we havechecked x-rays of fingers and other joints where the patients complained of pain or troubles. In 25 of 30 patients, we could find clearly defined osteoarthritis in the distal inter-phalagial (DIP) joint and about half of the thirty cases showed osteoarthritis of the first metatarsal, other finger joints and lumbar spine.
Considering these osteoarthritic changes in fingers and other joints, it is presumed that the generalized osteoarthritis should be participating in the etiology of spontaneous osteonecrosis of the knee.

View full abstract

Surgical fusion of the upper cervical spine was done in 17 patients, 13 women and 4 men, with rheumatoid arthritis. The average follow-up was 3, 4 years. Using the functional classification of the ARA, 4 patients were classified as being class I or II ; 10 in class i and 3 in class IV.
Our criteria for choosing the surgical method were as follows: (1) reducible or irreducible atlanto-axial subluxation, (2) with or without neural involvement, (3) with or without penetration of the dens, and (4) the active nature of rheumatoid arthritis. Atlanto-axial fusion was performed in 10 patients and occiputo-axial or subaxial fusion in 7.
A solid arthrodesis was obtained in all patients and a satisfactory result was produced except for the presence of neural involvement. As there are often progressive radiological changes in the cervical spine after initially successful surgery, long-term follow-up evaluation is necessary.

View full abstract

In rheumatoid arthritis, it is well known that changes of cervical spine are frequently seen by x-ray. However, little is known about how the changes occur. In the case described here, an autopsy was performed to investigate this mechanism.
A 58 year-old woman had rheumatoid arthritis since 1943. Treatment with corticosteroid and gold was started and continued until death. x-ray changes appeared in 1970. Neurological findings appeared and subaxial dislocation of the C3 vertebrae was present in x-rays in 1974. In 1984 she died of a respiratory dysfunction.
In synovial joints, proliferation and enlargement of synovium, infiltration of inflammatory cells, or plasma cells and lymphocytes, and pannus were present.
Rheumatoid nodules were found in the vertebral bodies, discs and ligamenta. Infiltration of inflammatory cells were observed in the enthesis of ligamenta. The x-ray cahnges of cervical spine depends on these histological findings.

View full abstract

For surgical treatment of symptomatic unstable cervical spines in RA, we have used halo vest in order to reduce subluxation of cervical vertebrae and to improve neurological involvement before operation and further to resume earlier and safer exercise right after operation.
In five patients with RA, spine fusion with the help of halo vest was performed. Two patients with subaxial subluxation had their cervical vertebrae partially removed for decompression of spinal cord, followed with anterior spine fusion. Postoperative immobilization with the use of halo vest was found to be very useful in those two cases for initiating earlier exercise in the ward.
Three RA patients with atlanto-axial and vertical subluxations were anesthetized with halo vest attached; and posterior spine fusion was subsequently performed. In these 3 cases also, halo vest immobilization was quite useful for improving neurological findings preoperatively and for resuming earlier exercise postoperatively as well.

View full abstract

The correlation between the thickness and the macroscopic changes of the articular cartilage of the tibial plateau was studied in order to reveal the meaning of the thickness of articular cartilage to the development of degenerative arthritis. Previously 52 cadaver knees from persons aged 49 to 85 years old had been examined to study macroscopic changes of the tibial plateau. The surface morphology and topographical distribution of the lesions were described for the submeniscal region of the tibial plateau and its uncovered region. The degenerative changes of the articular surface were examined by the naked eye for the following four grades of lesion; normal, fibrillation of the superficial layer, fragmentation and fissuring, and ulceration and/or eburnation. The 20 specimens with minimal change of the articular surface among those 52 cadaver knees were chosen, then dehydrated by alcohol and perfused in polyester resins. Each specimen was cut consecutively with a vertical milling machine in the frontal plane. The thickness of the articular cartilage in each cut was assessed.
Degenerative changes of the tibial plateau were more encountered at the uncovered region than the submeniscal region except at its lateral posterior segment. Gross degenerative change such as erosion, ulceration and eburnation was almost extirely localized at the posterior segment of the submeniscal region of the lateral tibial plateau, and at the intercondylar eminence region of a few knees. The distributed pattern of the cartilage thickness was classified into 3 types on each side of the tibial plateau. The thicker cartilage was distributed from the area of the uncovered region to the posterior segment of the submeniscal region. It was shown to be the same as the distribution of the degenerative changes of the tibial plateau. These areas that frequently encountered degenerative changes and had thicker cartilage were nearly equal to the so-called contact area of tibio-femoral articulation. According to these findings it is probable that the articular cartilage tends to be thickened at the weight-bearing area, and then degenerates due to the heavy loads and its own thickness.

View full abstract

Knee replacement with an artificial joints is ultimately for the purpose of ameliorating extreme pain and dysfunction from devastation of the joint caused by arthritis deformans, chronic rthumatism, injury, etc.
Many types of artificial joints have been developed, and are currently in use, yet we are still at the stage where there has been no conclusion as to which type is superior.
Since 1976 to the present, we have used the Okayama University Type Mark II and Kyocera Type Alumina Ceramic surface replacement type artificial knee joints, on 24 patients for the total of 33 joints. The patients consisted of 17 cases of RA and 7 cases of OA. The age range at the time of the surgery were from 28 years to 72, with the average age being 54 years. Clinical results were determined by comparing the patients' conditions before and after surgery, based on JOA judgement criteria concerning the three items of pain, range of movement and walking capacity. OA and RA were treated separately.
Regarding pain, 6 areas were investigated: no pain, pain when standing up, pain from walking, pain when moving without a load, pain when going up and down stairs and last of all spontaneous pain. For the range of movement 3 items where investigated: extension lag, F. T. A. and quadriceps fermoris muscle strength. Walking capacity was investigated under 5 items: independent walking, walking indoors, climbing and decending stairs, walking outdoors for 10 minutes or longer and normal walking. Concerning the knee joint flexing function when walking after surgery, stick pictures were used for a comparative study of normal patients, patients who had satisfactorily functioning knee joint and patients whose knee joint functions were defective.
1. With both the Mark-II type and the Kyocera Type, we are dissatisfied with the improvment in the knee joint R. O. M. With the Mark-II Type, the tibia component sometimes slips out towards the front in early movements following surgery. Some problems also remain with fixation. Fixation of the femoral component is insufficient and it loosens easily. Care should be taken with the setting angle of the component. Particular consideration is necessary in cases of high bone atrophy, as in RA.
As for settling of the tibia component, in the case of the Kyocera-type, we found 3mm within 3 months on the average; after 6 months, the region around the component catagmatizes. In preventing settling, the Mark-II is the same, but it is important that the component be established completely around the bone cortex.
Different sizes of the component are desirable.
If the angle which the tibia component forms with the longitudinal axis of the tibia is slanted, internal and external opposite deformation will occur, leading to curvature defects, and it will be easy for the components to loosen.
In reference to knee function during walking where stick pictures were used, the cases of knee joint curvature defects were reduced, as well as the angle of the curvature during walking, swing was small and knee extension time during the base period was long.

View full abstract

For many years we have been following Savastano's hemicompartmental replacements which were executed for OA limited to the compartment of a knee. This time we studied the results have passed since operation in cases in which more than five years, and reported them with some remarks.
The numbers of total cases which had the Savastano-type artificial knee, 19 knee joints in 18cases, i.e., 11 knee joints in 11 cases for women and 8 knee joints in 7 cases for men, and 17 inside knee joints and 2 outside knee joints. The average age at the time of operation was 62.5. The follow-up period was 2 to 7 years. For the group within 5 years after the operation (A group) and the group more than 5 years (B group), we made functional evaluauion by three university trial plans, disorder of the clear zone and of wire marker on X-ray and changes such as tibial plateau sinking and artificial knee loosening.
About 80% of cases within 5 years showed satisfactory results, the evaluation score of knee joint function was 80% or above; however, for the group of more than 5 years, FTA return, increases in movable zone limitation, etc., were observed. Loosening occurred on 3 out of 7 cases and revision was executed on 2 cases, with 1 case pending.
The discover what was behined the
1 Case factors (weight and activity degree on ADL)
2 Indications (OA of other components and development degree)
3 Prosthetic factors (supportability of tibial prosthesis against load)
The component replacement cases for the outside knee joint showed satisfactory results compared with the cases for the inside knee joint. However, more follow-up investigation will be necessary.
Although the short-term result of hemicompartment arthroplasty has a relatively satisfactory result, the long-term result has problems, and therefore, we must be careful about its application.

View full abstract

From 1978 through 1984, a total condylar-type knee prosthetic system was implanted in 20 knees in 16 patients with osteoarthritis (OA) and 28 knees in 24 patients with rheumatoid arthritis (RA) at Kyoto University Hospital. The scores for activities of daily living, walking distance, valgus-varus deformity, and pain significantly improved after the operation as evaluated by the knee joint scoring method. However, no difference was seen in range of motion of the knee. The mean preoperative flexion contracture of 18°improved to 3 degrees, but the mean preoperative flexion range of 106°decreased to 94 degrees.
Preoperatively, the scores in items such as walking distance, valgus-varus deformity and pain were significantly higher in RA patients comparing to those in OA patients, but extension of the knee and range of motion were superior in the latter group and the scores of total evaluation were not different between the two groups. Because the scores in items such as activity of daily living and walking distance were significantly higher in OA patients than in RA patients postoperatively, total scores were lower in RA group than in the OA group.
Variation of positioning of the femoral and tibial components showed no correlation with postoperative joint scores in this series, but the length of patellar tendon estimated by Insall-Salivati method showed a slight correlation with the range of extension and flexion. No loosening of components has been observed in this series.

View full abstract

Fifty-seven patients (69 knees) in whom the I/B posterior stabilized total condylar knee system was used have been followed for 0.5 to 4 years. This series included 23 patients (30 knee) with RA and 34 patients (39 knees) with OA. The average age of patients was 66 years, and the range was 42 to 80.
Evaluations were done before and after the operation using 6 check points : pain (30 points), R. O. M. (20 p.), flection contracture (10 p.), angular deformity (10 p.), gait (10 p.) and A. D. L. (10 p.) . The average score increased significantly from 41.0 to 77.5 after operation (p<0.05) .
Complications which were seen included one case each of late infection, myositis ossificans and femoral fracture. Compared to patients with normal total condylar prostheses, patients with posterior stabilized T. C. P. showed greater improvements in R. O. M. and flexed knee stability because of the increased posterior stability.

View full abstract

The results of a clinical study of 13 knees in 10 total knee replacement (TKR) patients after synovectomy in rheumatoid arthritis (RA) were reported.
All patients were female and classical RA (stage III, class III to IV) . Most of the patients had extension loss, valgus or varum deformity, slight or moderate inflammatory signs and gait disturbance at the time of knee replacement 7.3 years (mean) after the synovectomy. When the knee was replaced, the patients' average age was 47.9 years. The results of TKR (Kinematic knee) were mostly satisfactory. There was one case of mild infection, one of fat necrosis and one of skin necrosis.
As there was high grade fibrosis in each synovectomized knee, stripping and resection of the fibrosis were needed in TKR. The design of the skin incision in TKR was very important, because a longitudinal incision made on the knee synovectomized through bilateral incisions easily caused skin necrosis or delayed skin healing. Most knees had bone defects on the tibial plateaus; however, in these cases bone defects were small. Therefore these defects were fixed with bone cement. Replacement of patella was performed in only 3 knees. Because of the high anterior flange of the femoral compornent, the patello-femoral (P-F) joint in the Kinematic knee is hemiarthroplastic without the pateller dome. From the 10 knees without the pateller dome, only one knee had tenderness in the P-F joint.

View full abstract

Synovectomy is frequently carried out as a surgical therapy in chronic articular rheumatism patients and many surgeons have noted subsidence or relief of pain after conventional synovectomy. However, there often is either loss of joint motion or a prolonged recovery period. We have performed washing of the knee joint and subsequently partial synovectomy with a punch under direct vision with an arthroscope. This method gave rise to a temporary remission of the symptoms, but was followed by recurrence in many cases.
Recently we carried out resection of the inner layer of the synovial membrane with a shaver under arthroscopic control in 32 knees of 20 cases and obtained good results jn 81 per cent. Clinical follow up suggests that synovectomy performed with a shaver produces results almost comparable with those of conventional synovectomy.
The advantages of this method are as follows. Because of the small incision, bleeding is minimized, post operative pain is greatly decreased, recovery of function is greatly accelerated, and hospitalization is shortened. A few complications were noticed with this method, But none were serious. The method of synovectomy with a shaver under an arthroscopie, along with problems in its performance and progress between 6 months and 3 years after the surgery are reported with some discussion.

View full abstract

An attempt was undertaken to single out the factors which would influence the recovery process of“extension lag”of the knee joint that were totally replaced with artificial prostheses.
In total, forty-eight knee joint of 37 RA patients (32 women, 5 men: age ranging from 31 through 73 years old) which were totally replaced with the Kodama-Yamamoto knee prostheses (Okayama Univ. Mark II type) were evaluated.
Preoperative objective measurements, such as degrees of the flexion contracture of the knee joint, manual muscle testing of the quadriceps muscles, time to walk 10 meters, were analyzed against the postoperative number of the day at which the degree of the extension lag of the operated knee joint on its way of recovery attained 20, and 10 degrees.
Results of preoperative MMT of the quadriceps muscles and severity of the flexion contracture of the knee joint to be operated on were also utilized to perform a‘grouping’study.
Our study clearly demonstrated that residual muscle strength of the quadriceps muscles played a more decisive role in the recovery of the“extension lag”of the artificially replaced knee joint than the severity of the flexion contracture of the joint per se.

View full abstract