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Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_3 | Pages 25 - 25
1 Jan 2016
Masuda Y Ozeki S
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Purpose

The purpose of this study was to clarify the relationship between the laxity of surrounding soft tissue and artificial joint kinetics during knee articulation, where total knee arthroplasty had been performed using ceramic LFA artificial knee joints (LFA-TKA below) from Japan Medical Materials (JMM).

Materials Methods

The subjects of the study were 47 knees in 40 LFA-TKA recipients whose cooperation could be obtained. The CR type joint (posterior cruciate retention design) was used in 33 knees in 27 recipients and the PS type joint (posterior cruciate stabilizer design) was used in 14 knees in 13 recipients. OA patients received 30 CR type and 8 PS type joints while RA patients received 3 CR type and 6 PS type joints. For analysis of post surgery knee joint kinetics, using digital fluoroscopy, lateral images were taken of knee motion from a loaded squat position to the erect standing position. Using Knee Motion® software the imaging data was evaluated for 1) femoral rollback, 2) tibial axial rotation patterns, and 3) pivot center position, from analysis of lateral and medial condylar translation (femoral components) at the point of contact with the tibial insert, starting from the extended position. Subsequent imaging under medial-lateral and posteroanterior stress was performed to measure the medial-lateral dihedral angle changes and posteroanterior movement, and the relationship of those factors to the dynamic patterns was evaluated.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 11 | Pages 1516 - 1519
1 Nov 2005
Togawa S Yamami N Nakayama H Mano Y Ikegami K Ozeki S

The Mangled Extremity Severity Score (MESS) may be used to decide whether to perform amputation in patients with injuries involving a limb. A score of 7 points or higher indicates the need for amputation. We have treated three patients with a MESS of 7 points or higher, in two of which the injured limb was salvaged. This scoring system was originally devised to assess injuries to the lower limb. However, a MESS of 7 points as a justification for amputation does not appear appropriate when assessing injuries to the major vessels in the upper limb.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 217 - 217
1 Nov 2002
Nakamura Y Ozeki S Yasumura K Koike H Jinnai M Nohara Y
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Introduction: The confocal laser-scanning microscope (CSLM) was recently introduced. We have invented a new transmission type of double pass CSLM. This study is the first report of valuable pathological information related to bone tumor being derived using such microscopy.

Methods: The most remarkable characteristic of this microscope is the use of two laser beams twice passing through the specimen. This laser microscope can detect signals from coloring sources such hematoxylin eosin (HE) stain and obtain clear images of the organelles. The images presented here were built up as electronic signals, processed by computer analysis, and stored in frame memory. Specimens of the giant cell tumor stained with HE were examined directly by the phase contrast mode of this microscope and computer analysis was performed. Double pass CSLM and conventional microscopic views were then compared.

Results: We successfully observed sharply and sensitively positive fine granules in our laser microscopes provided higher magnification, resolution and contrast than did conventional ones. CSLM provides high magnification, contrast, resolution and can be used to observe living cells in culture in real time. With the combination of double pass CSLM and computer analysis, clear images of the subcellular organelles of various cells were successfully visualized.

Conclusion: This study suggests that double pass CSLM is an important tool for analyzing the cellular ultrastructure, physiology, and function of bone tumor. Double pass CSLM is also a powerful new instrument for orthopedics, complementing light and electron microscopy.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 262 - 262
1 Nov 2002
Negishi T Ozeki S Yao H Nohara Y
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Introduction: Functional knee braces are commonly used after ACL reconstruction surgery. However, the study to evaluate the contributions of the knee brace is a few. We investigated the effects of knee brace prospectively.

Methods: From 1993 to 1996, forty eight patients with 48 knees were treated with autogenous ACL reconstruction. The patients were randomly divided to two groups; twenty five patients (group B) used knee brace for one year and the other 23 patients (group NB) were free from bracing. Forty two patients were followed over two years. The averaged follow-up period was 27 mouths and the averaged age at surgery was 24.5 years. The semitendinosus and the gracilis tendon in the contralateral side were used to make triple looped (six strands) substitute. Bone tunnels were made at the appropriate site using inside-out technique under arthroscopy assistance. Polyester meshes were connected to the substitute and fixed to the tibia and femur with staples after grafting through the bone tunnels. The same rehabilitation protocol was used for both patients group. Functional outcomes were evaluated with IKDC score.

Results: The rate of category A, B ,C and D in the group B were 52%, 44%, 4% and 0%. Those in the group NB were 65%, 26%, 9% and 0% respectively. There is not any Statistically significant difference between the two groups.

The joint stability were measured with stress x-p using TELOS device. The anterior displacement ratio improved from 73±4.9%(mean ±sd) to 64±4.6% in group B, and it also improved from 72±4.0% to 62±2.9% in group NB. Statistically significant improvements were obtained after surgery in both the two groups, however, no statistically significant difference of stability were found between the two groups.

Conclusion: These results suggest that the functional knee brace is not indispensable when the hamstring substitute is used for ACL reconstruction with secure fixation methods.


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 225 - 225
1 Nov 2002
Ozeki S
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Introduction: Most physicians agree that initial treatment for a newborn child with clubfoot should be nonoperative. Some children with rigid deformities, however, may need a soft tissue release operation at an early age. The optimal timing of such surgery and for whom remain controversial questions. We prospectively followed patients treated in our clinic under temporal protocol and analyzed results in order to answer these questions.

Methods: From 1979 to 1989, 132 infants with 185 club-feet visited the Hokkaido Univ. before they were three months old. Eighty eight patients with 124 feet were followed over a 10 year period. The averaged follow-up period was 15.2 years. Corrective casts were applied for no longer than 3 months. If the lateral tibio-calcaneal (TC) angle became less than 90°, a Denis Browne splint was used. If this angle was still larger than 90°, postero-lateral release was performed within a month after casting. Surgery was also performed for children whose deformities continued increasing after conservative treatment. McKay’s scoring system was used to evaluate the final clinical results. The results of patients needing major revision surgery were evaluated “failure”.

Results: Forty-nine feet were treated conservatively. Of these 35 were evaluated as good or excellent and seven were evaluated as poor or failure. Forty-three feet were underwent surgery before one year of age; an additional 32 feet underwent surgery after one year of age. Thirty-three feet were evaluated good or excellent and 19 feet were evaluated as poor or failure. At 6 months of age the lateral TC angle of the patients treated non-operatively and evaluated as good or excellent was 68.4 ± 14.3° (Mean ± S.D.), and the lateral TC angle of patients who underwent surgery after one year of age and patients who were treated non-operatively but evaluated as poor or failure was 80.0 ± 9.2°. There are statistically significant difference between these two groups. The age at surgery of patients evaluated as good or excellent was 12.6 ± 12.4 months old, and that of patients evaluated as poor or failure was 5.1 ± 3.0 months old.There are also statistically significant difference between these two groups.

Conclusion: Our results suggest that surgery is indicated for patients whose TC angle at 6 months of age is greater than 70°, and that the optimal timing for soft tissue release is later than 8 months of age.