Tetsuto Sasaki

The mechanics of treatment of the osteoarthritic knee with a wedged insole.

The mechanism of the static effects of the wedged insole for the medial osteoarthritic knee was studied in ten women. They stood with one leg on the wedged sole board, and the change of the position of the line through the center of gravity, the femorotibial angle, the tibiocalcaneal angle, and the spatial position of the whole lower limb were investigated using load transducers and roentgenograms. When the subjects stood on the wedged sole board, the line through the center of gravity and femorotibial angle did not change. The change in the spatial positions of the lower limb (p less than 0.02), i.e., the mechanical axis of the lower limb near an upright position, and the change of the calcaneus to valgus direction in the subtalar joint (p less than 0.01) were observed. These changes were considered from two-dimensional analysis to reduce the excessive loading on the medial joint surface and the excessive tensile force of the lateral side. The wedged insole thus proved effective for the conservative treatment of the medial compartment osteoarthritic knee.

Exercise after anterior cruciate ligament reconstruction. The force exerted on the tibia by the separate isometric contractions of the quadriceps or the hamstrings.

The anterior or posterior drawer force exerted on the tibia by the separate isometric contractions of the quadriceps or hamstrings at various angles of knee flexion was examined in 20 healthy males. A two-dimensional model was analyzed using roentgenographic films. In separate isometric contractions of the quadriceps, the mean value of the anterior drawer force was equivalent to 14% of the tension of the quadriceps at 5 degrees knee flexion. The value decreased with the increase in the angle of knee flexion. The mean angle at which the anterior drawer force became zero was 45.3 degrees +/- 12.5 degrees. When the angle was increased further, the posterior drawer force gradually increased. In separate isometric contractions of the hamstrings, the posterior drawer force was exerted at all angles of flexion. Thus, during the early stage of rehabilitation after the anterior cruciate ligament injury, the quadriceps exercise by isometric muscle contraction should be performed with the knee flexion at more than 70 degrees (mean +/- 1.96). Exercise of the hamstrings by isometric muscle contractions can be carried out regardless of flexion angle.

Clinical Evaluation of the Treatment of Osteoarthritic Knees Using a Newly Designed Wedged Insole

For the purpose of investigating the clinical efficacy of a newly designed wedged insole, 149 patients with medial osteoarthritis of the knee were followed from one year to five years and five months. A rating system for pain, walking ability, and both were used for evaluation of the clinical results. Comparing two groups consisting of 107 patients with early radiographic stages (Stage I or II), 67 patients (Group I) treated with both a wedged insole and anodyne (Indomethacin 600 mg/day) showed a significantly greater improvement than 40 patients (Group II) treated with anodyne alone. Analyzing the therapeutic efficacy of the wedged insole according to the radiographic stage, the prescription of a wedged insole was significantly more effective for patients with mild osteoarthritis (Stages I, II, and III), and ineffective for those with advanced osteoarthritis (Stage IV). The wedged insole, designed on the basis of an established hypothesis, represents an excellent means of conservative treatment for early medial osteoarthritis of the knee.

SIMULTANEOUS MEASUREMENT OF CHANGES IN LENGTH OF THE CRUCIATE LIGAMENTS DURING KNEE MOTION

The changes in length of electrolyte-in-rubber strain-gauge transducers implanted along the fibers of the anterior (ACL) and posterior (PCL) cruciate ligaments of the human anatomic specimen knees were measured simultaneously and continuously during knee motion. In unconstrained flexion and extension of the knee, all transducers in the ACL showed the maximum shortening peak at about 30 degrees flexion. After this, the length of the transducers in the anterior bundle increased, whereas those in the posterior bundle remained shortened. Transducers in the anterior and posterior bundles of the PCL, on the other hand, showed maximum lengthening peaks at approximately 50 degrees and 0 degrees flexion, respectively. The middle bundle of the PCL showed a smaller change. When simulated quadriceps forces were applied, the transducers in the ACL lengthened and those in the PCL shortened. At more than 90 degrees, however, the changes in length decreased. After cutting the ACL, the quadriceps force increased the shortening of the PCL.

Muscle exercise after anterior cruciate ligament reconstruction: biomechanics of the simultaneous isometric contraction method of the quadriceps and the hamstrings

Biomechanical analysis of two-dimensional models composed from roentgenographic pictures and electromyographic analysis on simultaneous isometric contraction exercises of the quadriceps and hamstrings were conducted in 20 healthy adult males. During simultaneous isometric contraction at 5 degrees knee flexion, an anterior drawer force equivalent to 15% of the tension of the quadriceps was exerted to the tibia, and decreased with increased angle of flexion. The mean angle at which this force became zero was 7.4 degrees, with a standard deviation of 5.0 degrees. When the angle increased further, a posterior drawer force to the tibia occurred and gradually increased. Each tension of the quadriceps or hamstrings during maximum simultaneous isometric contraction of the quadriceps and hamstrings was estimated as 30%-60% of that during separate isometric contractions of each muscle. In the early stage of the rehabilitation after the anterior cruciate ligament reconstruction, the simultaneous isometric contraction of the quadriceps and the hamstrings is useful as one of the muscle exercise methods because it can be performed safely with the knee position near the full extension and can generate sufficient muscle force to be an effective exercise.

Malignant granular cell tumor of the radial nerve. An autopsy observation with electron microscopic and tissue culture studies

Malignant granular cell tumor closely associated with the radial nerve in the left upper arm, was found in a 34‐year old man. The tumor increased rapidly in size, was locally invasive and showed recurrence and metastases to lymph nodes and the lungs. The tumor was composed solely of granular cells and its histological features were very similar to those of benign granular cell tumors. However, considerable variation of cellular size and shape, hyperchromatic plump nuclei, and some disordered cellular arrangement were thought to be significant indications of malignancy. Ultrastructural study of the tumor revealed many lysosome‐like dense granules in the cytoplasm. The presence of a few axon‐like cytoplasmic processes between granular cells and the intimate anatomical association of the tumor with the radial nerve seemed to support the concept of peripheral nerve origin of the malignant granular cell tumor.

Transepiphyseal plate osteotomy for severe tibia vara in children: follow-up study of four cases

Transepiphyseal plate osteotomy of the medial tibial condyle was performed in three children (four knees) with severe progressive tibia vara and excessive ligamentous laxity. Two knees with Blount disease underwent tibial valgus osteotomy and epiphysiodesis associated with transepiphyseal plate osteotomy, and two knees with pseudoachondroplasia underwent tibial valgus osteotomy. Follow-up study at the time of skeletal maturity revealed satisfactory alignment of the leg, favorable congruity of the joint, and good ligamentous stability in all cases. Our experience indicates that the present procedures are excellent, although there are very few documented cases and almost no description of the postoperative clinical courses.

Steroid-induced osteonecrosis of the patella.

Two cases of previously unreported steroid-induced osteonecrosis of the patella were investigated. The first case was a 46-year-old man who had been receiving steroid therapy for three years for treatment of bronchial asthma. The second was a 32-year-old woman who had been receiving steroid therapy for nine years as treatment of systemic lupus erythematosus. Both reported slight knee pain. The roentgenographic findings revealed increased radiodensity with radiolucency of the upper one-half of the patella. A trephine biopsy revealed focal areas of dead trabecular bone.

HIGH-GRADE SURFACE OSTEOSARCOMA OF THE LEFT ILIUM A Case Report and Review of the Literature

A rare case of high‐grade surface osteosarcoma of the left ilum is reported. Trephine biopsy performed on a 31‐year‐old woman suffering from a huge tumor of the left buttock revealed high‐grade osteosarcoma, and hemipel‐vectomy was undertaken. The surgical specimen showed that the tumor was present on the surface of the left ilium. Ten months after the operation, the patient died of brain metastasis. From these results, we considered this case to be one of high‐grade surface osteosarcoma. ACTA PATHOL JPN 38: 235 ‐240, 1988.

Postoperative evaluation of quadriceps contracture in children: comparison of three different procedures.

Sixty-five patients (73 legs) with quadriceps contracture involving mainly the rectus femoris muscle were operated on. The average follow-up was 6.3 years. In the postoperative overall results, the rating system score was significantly decreased from a preoperative mean of 7.0 points to a postoperative mean of 1.9 points. Three different operative methods were used: release of the pelvic origin, sartorius plasty and release of the pelvic origin, and sartorius plasty and release of the fibrosis. The most satisfactory results were obtained in the group treated by release of the fibrosis.