Biomedical subjects

Mitsuo Ochi

Publications and source records attributed to Mitsuo Ochi.

At least 109 records · Page 6Linked to original sources

PubMed2004

Anterior interosseous nerve palsy after reduction and percutaneous pinning of open fractures of the radius and ulna.

We report a case of an anterior interosseous nerve palsy after closed reduction and percutaneous pinning of open fractures of the radius and ulna in an adult. Operative findings showed that the anterior interosseous nerve was trapped between the distal and proximal part of the fractured radius. Treatment by neurorrhaphy gave a satisfactory result.

Fracture Fixation, Intramedullary↗

PubMed2004

Cervical angina caused by atlantoaxial instability.

Cervical angina is defined as a paroxysmal precordialgia that resembles true cardiac angina caused by cervical spondylosis. Cervical angina most commonly results from compression of the C7 ventral root. We present here a case of cervical angina caused by atlantoaxial instability. This case had marked atlantoaxial instability but no flexibility of the middle to lower levels of the cervical spine. Although there was mild C7 root compression on the radiologic findings, the chest pain was induced by neck motion, and the precordialgia disappeared after posterior atlantoaxial fusion without C7 root decompression. Therefore, we diagnosed this case as cervical angina caused by spinal cord compression at the C1-C2 level. It was speculated that a perturbation of the sympathetic nervous system or a hypofunction of the pain suppression pathway in the posterior horn of the spinal cord caused the pectoralgia. Although cervical angina is a rare disease, physicians should be aware of it; if there are no abnormal findings on cardiac examinations for angina pectoris, they should examine the cervical spine. Cervical angina due to atlantoaxial instability is one of the differential diagnoses of precordialgia.

Afferent Pathways↗

PubMed2004

Diagnosis and treatment of combined intra-articular disorders in acute distal fibular fractures.

BACKGROUND: Some patients have residual ankle pain and disability after the treatment of an ankle fracture, despite the fracture site being well aligned. We identified intra-articular disorders in distal fibular fractures and sought to clarify the results of their operative treatment. METHODS: This is a prospective, randomized study. Seventy-two patients with Weber type B distal fibular fractures were randomly treated with arthroscopy-assisted open reduction and internal fixation (AORIF) or with open reduction and internal fixation without arthroscopy (ORIF). In the AORIF group, the patients were followed for a mean duration of 3 years 4 months (range, 2 years 4 months-4 years 5 months). There were 27 male patients and 14 female patients. The mean age of the patients at the time of surgery was 36 years (range, 20-64 years). In the ORIF group, the patients were followed for a mean duration of 3 years 5 months (range, 2 years 7 months-4 years 5 months). There were 21 male patients and 10 female patients. The mean age of the patients at the time of surgery was 38 years (range, 20-58 years). We described intra-articular disorders in the AORIF group using ankle arthroscopy and compared their operative results with those of the ORIF group. RESULTS: Including duplication, the arthroscopic findings showed 30 cases with osteochondral lesions of the talar dome (73.2%) and 33 cases with tibiofibular syndesmosis disruptions (80.5%). Six cases (14.6%) had no combined disorders. The mean AOFAS score was 91.0 +/- 3.5 (range, 85-100) in the AORIF group, in contrast to 87.6 +/- 5.5 (range, 77-97) in the ORIF group (p = 0.0106). CONCLUSION: In the treatment of distal fibular fractures, precisely diagnosing and treating the combined intra-articular disorders is important for gaining satisfactory clinical results.

Adult↗

PubMed2004

Articular cartilage repair using tissue engineering technique--novel approach with minimally invasive procedure.

Articular cartilage has very limited potential to spontaneously heal, because it lacks vessels and is isolated from systemic regulation. Although there have been many attempts to treat articular cartilage defects, such as drilling, microfracture techniques, soft tissue grafts or osteochondral grafts, no treatment has managed to repair the defects with long-lasting hyaline cartilage. Recently, a regenerative medicine using a tissue engineering technique for cartilage repair has been given much attention in the orthopedic field. In 1994, Brittberg et al. introduced a new cell technology in which chondrocytes expanded in monolayer culture were transplanted into the cartilage defect of the knee. As a second generation of chondrocyte transplantation, since 1996 we have been performing transplantation of tissue-engineered cartilage made ex vivo for the treatment of osteochondral defects of the joints. This signifies a concept shift from cell transplantation to tissue transplantation made ex vivo using tissue engineering techniques. We have reported good clinical results with this surgical treatment. However, extensive basic research is vital to achieve better clinical results with this tissue engineering technique. This article describes our recent research using a minimally invasive tissue engineering technique to promote cartilage regeneration.

Animals↗

PubMed2004

Arthroscopic drilling with debridement of remaining cartilage for osteochondral lesions of the talar dome in unstable ankles.

BACKGROUND: Arthroscopic examination has shown that the regenerative cartilage that appears after arthroscopic drilling for the treatment of osteochondral lesions of the talar dome does not always cover the cartilage defect sufficiently. HYPOTHESIS: The remaining degenerative cartilage at the lesions may obstruct the healing of the articular cartilage. STUDY DESIGN: Prospective cohort study. METHODS: Thirty-nine patients underwent arthroscopic drilling that kept the remaining cartilage at the lesion (group A), and 30 patients underwent arthroscopic drilling that removed the remaining cartilage at the lesion (group B). At 1 year after the operation, we performed ankle arthroscopy to evaluate the cartilage condition. RESULTS: The arthroscopic findings revealed that in group A, 11 cases (28.2%) were improved, 12 cases (30.8%) were unchanged, and 16 cases (41.0%) had deteriorated; in group B, 27 cases (93.1%) were improved and 2 cases were unchanged. There were significant differences between group A and group B in the rate of cases whose cartilage condition was seen to improve under arthroscopic examination (P < 0.0001). CONCLUSIONS: The study shows that in the treatment of osteochondral lesions of the talar dome, the removing of the remaining degenerative cartilage may be of some benefit in the treatment of these lesions.

Adolescent↗

PubMed2004

Arthroscopic treatment for anterior impingement exostosis of the ankle: application of three-dimensional computed tomography.

The purpose of this study was to evaluate the operative results of excision of anterior impingement exostoses of the ankle. Preoperative three-dimensional computed tomography (3DCT) was used to make the diagnoses. The authors evaluated 16 ankles of 16 patients who underwent arthroscopic resection of the osteophytes of their anterior distal tibia or dorsal talus. They were followed up for 24-51 months. All 16 patients had 3DCT preoperatively, which allowed the authors to determine the exact location, shape, size, and number of the osteophytes. All of the osteophytes were resected using arthroscopic techniques. At the time of the most recent follow-up, the mean AOFAS score was 80.5 +/- 4.9 points at preoperation, and 97.0 +/- 3.7 points at the most recent follow-up. There were significant differences between the pre- and postoperative AOFAS scores and those of the most recent follow-up period for each group (p <.0001). It is necessary to clarify the location, size, shape, and number of all of the osteophytes preoperatively using 3DCT, and to then resect them all.

Adolescent↗

PubMed2004

[Biology of articular cartilage repair--present status and prospects].

The cartilage response to injury differs from the classic wound healing because of two important features of the cartilage structure; lack of vascular system and rich matrix preventing chondrocyte from migration to the injury site. Three distinct types of cartilage injuries can be identified based on the depth of injury and the repair response: microdamage, chondral injury, and osteochondral injury. There have been numerous attempts to repair cartilage injury, however their results have reinforced that articular cartilage has limited potential to repair itself. However, current research is helping to clarify the mechanism of cartilage injury and repair based on its gene expression. Biology, gene therapy, and tissue engineering may provide a breakthrough to treat cartilage injury.

Animals↗

PubMed2003

Progressive collapse of transposed necrotic area after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head induces osteoarthritic change. Mid-term results of transtrochanteric rotational osteotomy for osteonecrosis of the femoral head.

INTRODUCTION: Osteonecrosis of the femoral head is usually progressive, and once collapse of the femoral head develops, joint destruction almost invariably follows. Therefore, for partial osteonecrosis of the femoral head, various types of osteotomies have been developed in an attempt to save the femoral head and maintain the natural function of the hip joint. MATERIALS AND METHODS: We reviewed 25 hips in 21 patients for a mean follow-up period of 6.4 years after Sugioka's transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head. RESULTS: The clinical results were excellent or good in 20 hips (80%), and radiological success was observed in 15 hips (60%) with an absence of both collapse of the newly established weight-bearing area of the femoral head and narrowing of the joint space. Progressive collapse of the transposed necrotic area was noted in 10 hips (40%), and of these 10 hips, narrowing of the joint space was observed in 7 (70%) at follow-up. A significant correlation was demonstrated between progressive collapse of the transposed necrotic area and narrowing of the joint space. Growth of an osteophyte of the femoral head was observed postoperatively in 16 hips (64%), particularly at anterior and lateral sites of the femoral head. CONCLUSIONS: Though collapse of a new weight-bearing area can be prevented, progressive collapse of the transposed necrotic area induces anterior joint instability, giving rise to osteoarthritic change. It is therefore concluded that prevention of the collapse of the transposed necrotic area is important for satisfactory long-term results.

Adult↗

PubMed2003

Bone remodeling after impacted cancellous allograft in revision hip arthroplasty based on (99m)Tc-MDP bone scintigraphy.

INTRODUCTION: Impacted cancellous allograft for the femur reported by Gie et al. (1993) has resulted in a good outcome. Revascularization of the graft was proven with plain radiographs or in some cases, biopsy and autopsy. We have attempted to document the change in appearance of impacted cancellous allograft in the femur over time on scintigraphic scans. MATERIALS AND METHODS: Bone scintigraphy was conducted following total hip arthroplasty of 20 hips without complication using impacted cancellous allograft. At 6 weeks, 1, 2 and 4 years postoperatively, uptake at 5 regions of interest around the femoral component sites was measured. RESULTS: At all 5 regions of interest, uptake was significantly decreased at 1 year postoperatively compared with that at 6 weeks postoperatively. At 2 and 4 years postoperatively, uptake was about 2-fold that of the normal femur in the greater trochanter, lesser trochanter, and stem tip and had decreased to almost the normal level at the lateral stem and medial stem. CONCLUSION: In revision hip arthroplasty using impacted cancellous allograft, remodeling of the grafted bone of the femur was still incomplete, particularly at the greater trochanter, lesser trochanter, and stem tip even after 4 years postoperatively. It is felt that further time is required for remodeling.

Aged↗

PubMed2003

Intradural extramedullary mass formation in spinal cord sarcoidosis: case report and literature review.

STUDY DESIGN: A case of myelopathy caused by intradural extramedullary spinal cord sarcoidosis. OBJECTIVES: To report a rare case of mass formation in spinal cord sarcoidosis and discuss the diagnostic approach and therapeutic management of this condition. SUMMARY OF BACKGROUND DATA: Spinal cord sarcoidosis is a rare condition that is difficult to diagnose, and intradural extramedullary mass formation is even rarer. MATERIALS AND METHODS: A 42-year-old woman first noticed numbness in her fingers, and these symptoms gradually spread to her hands and feet. MRI revealed an intradural extramedullary mass, as confirmed by an isointensity T1 and low-intensity T2 signal, and also enhanced by Gd-DTPA. The authors suspected the mass to be a meningioma and performed surgery to resect it. RESULTS: The mass was observed through the dura, and it was twined with the rootlet. After surgery, the patient experienced temporary paralysis of her right upper extremity, followed rapidly by almost complete neurologic recovery. Bilateral hilar lymphadenopathy was noted and this was diagnosed histologically as lung sarcoidosis. One year after surgery, a complete AV block occurred because of heart sarcoidosis and a pacemaker was inserted. CONCLUSIONS: Spinal cord sarcoidosis is rare disease and is difficult to diagnose, but when a mass is present in the spinal canal, it is important to remain open to the possibility of spinal cord sarcoidosis. Besides if it is diagnosed as spinal cord sarcoidosis, it is also important to remain systemic sarcoidosis before, during, and after surgery to check general conditions and to guide appropriate treatment.

Adult↗

PubMed2003

Injectable magnetic liposomes as a novel carrier of recombinant human BMP-2 for bone formation in a rat bone-defect model.

Small-sized magnetic liposomes with incorporated recombinant human bone morphogenetic protein-2 (rhBMP-2) were prepared, and the efficiency for bone formation after topical injection was evaluated in a rat bone-defect model. A critical-sized segmental bone defect was created in the mid-part of the femoral shaft, and a permanent magnet was attached. Topical injection onto the defects was performed with different liposomal preparations (nonmagnetic and magnetic liposomes) using different treatment modalities (different doses and different treatment timing of rhBMP-2). Weekly evaluations were made radiographically and microcomputed tomographically, histologically, and/or by mechanical testing at 9 weeks after surgery. A single topical application of magnetic liposomes with an appropriate amount of rhBMP-2 (approximately 3 microg) incorporated under magnetic induction immediately after surgery was effective for new bone formation. The combined treatment of topical magnetic rhBMP-2 liposomes and magnetic implantation at the injury site was effective for the treatment of bone defects. This injectable carrier for BMP is expected to have many advantages over solid carriers because it can be prepared easily and can be less invasively applied to the injured site at any time after surgery.

Animals↗

PubMed2003

Harvesting hamstring tendons for ACL reconstruction influences postoperative hamstring muscle performance.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction using hamstring tendons has recently received attention because of less donor site morbidity. It has been reported that harvesting hamstring tendons has little effect on postoperative hamstring muscle performance based on the peak torque value of the hamstring strength. However, recent studies have clarified some adverse effects of harvesting hamstring tendons. There is still argument about the influences of harvesting hamstring tendons on postoperative hamstring muscle performance. The purpose of this study was to evaluate the postoperative hamstring muscle performance measured by various parameters after harvesting hamstring tendons for ACL reconstruction. PATIENTS AND METHODS: We evaluated the postoperative hamstring muscle performance after harvesting hamstring tendons in 58 patients who underwent ACL reconstruction. We assessed peak torque value, total work, and peak torque angle in the isokinetic hamstring strength test and active knee flexion angle. We classified the patients into three groups according to the type of hamstring used for ACL reconstruction: 1) the autologous semitendinosus tendon (ST); 2) the autologous ST and the gracilis tendon, which were harvested from the ipsilateral knees; and 3) allogeneic fascia lata. RESULTS: This study clearly demonstrated that the peak torque value and total work in the patients in each group compared to preoperative normal knees were not statistically different; however, the more hamstring tendons were harvested, the more loss of active knee flexion angle was observed and the more the peak torque angle was shifted to a shallow angle, suggesting that the hamstring strength might be weaker at the deep flexion angle. CONCLUSION: Physicians should recognize that the ACL reconstruction using autologous hamstring tendons is not appropriate for sportsmen or women who are required to flex their knees deeply or powerfully in their performance.

Adolescent↗

PubMed2003

Transplanted neuronal progenitor cells in a peripheral nerve gap promote nerve repair.

A basic experiment of peripheral nerve regeneration using neuronal progenitor cells embedded in collagen gel was performed in a rat sciatic nerve defect. First, when neuronal progenitor cells derived from the fetal rat hippocampus were cultured in atelocollagen-containing medium, neurospheres positive for anti-nestin antibody were confirmed after 8 days. These cells differentiated into astrocytes positive for anti-glial fibrillary acidic protein (GFAP) antibody, oligodendrocytes positive for anti-galactocerebroside (GalC) antibody and neurons positive for anti-neurofilament 200 (NF200) antibody, and they were capable of extending axons. They also differentiated into Schwann-like supportive cells positive for anti-s100 and anti-p75 antibody. Next, a 15-mm defect was prepared in the sciatic nerve of mature rats, and the nerve was bridged with a silicone tube filled with neuronal progenitor cells (1 x 10(5)) embedded in collagen gel. The transplanted neuronal progenitor cells were labeled in advance with 5-bromo-2-deoxyuridine (BrdU). When the regenerated tissue was examined 6 weeks and 10 weeks after grafting, the number and diameter of myelinated fibers were significantly increased compared with a control tube without neuronal progenitor cells. Action potentials were detected in the regenerated nerve. Also, cells positive for both anti-BrdU antibody and anti-S100 or anti-p75 antibody were observed in the regenerated tissue, and part of the grafted neural stem cells were considered to have differentiated into Schwann cell-like supportive cells. From these results neuronal progenitor cells derived from the fetal rat hippocampus are considered to retain their proliferative and differentiating abilities in collagen gel, and when transplanted to a site of peripheral nerve defect, part of them differentiate into supportive cells and they contributed to promotion of axonal regeneration.

Animals↗

PubMed2003

Injury of the tibiofibular syndesmosis: value of MR imaging for diagnosis.

PURPOSE: To compare the use of magnetic resonance (MR) imaging with the use of arthroscopy for the diagnosis of tibiofibular syndesmotic injury. MATERIALS AND METHODS: This study involved 58 patients who had ankle sprains or distal fibular fractures and underwent surgery. All patients were examined with MR imaging for diagnosis of tibiofibular syndesmotic injury. When MR imaging revealed ligament discontinuity (criterion 1) or either a wavy or curved ligament contour or nonvisualization of the ligament (criterion 2), the injury was considered to be a ligament disruption. After MR imaging, ankle arthroscopy was performed in all patients for a definitive diagnosis of ligament disruption. RESULTS: Arthroscopic findings showed anteroinferior tibiofibular ligament (AITFL) disruption in 28 patients and posteroinferior tibiofibular ligament (PITFL) disruption in five patients. When an MR imaging diagnosis was based on criterion 1 only, the diagnosis of AITFL disruption was made with a sensitivity of 100%, a specificity of 70%, and an accuracy of 84%, and the diagnosis of PITFL disruption was made with a sensitivity of 100%, a specificity of 94%, and an accuracy of 95%. When an MR imaging diagnosis was based on criteria 1 and 2, the diagnosis of AITFL disruption was made with a sensitivity of 100%, a specificity of 93%, and an accuracy of 97%, whereas the diagnosis of PITFL disruption was made with a sensitivity of 100%, a specificity of 100%, and an accuracy of 100%. CONCLUSION: MR imaging with use of both criteria is highly accurate for the diagnosis of tibiofibular syndesmotic disruption.

Adolescent↗

PubMed2003

Bone-preserving prosthesis with a single axis for treating osteonecrosis of the femoral head: midterm results for the thrust plate hip prosthesis.

We studied 27 patients (31 joints) who underwent total hip arthroplasty (THA) using the thrust plate hip prosthesis (TPP) for osteonecrosis of the femoral head. The mean follow-up period was 56 months (range 38-72 months). Clinical evaluation by the Merle d'Aubigne and Postel system showed a significant improvement from a preoperative mean score of 8.1 to a final mean follow-up score of 16.6. Mechanical loosening developed about 1 year postoperatively in one joint with a bone defect. Grade 1 stress shielding was observed in four joints. Although indications for the TPP are restricted to certain cases, unlike the conventional intramedullary stem, much can be expected of TPP. It is an outstanding prosthesis for osteonecrosis of the femoral head of young patients in terms of bone preservation and physiological load transfer.

Adult↗

PubMed2003

Osteochondral lesions of the talar dome associated with trauma.

PURPOSE: The purpose of this study was to clarify the differences in the causes of osteochondral lesions (OCL) of the ankle based on the presence of distal fibular fractures and lateral instability of the ankle. TYPE OF STUDY: Case series. METHODS: We evaluated 92 cases of distal fibular fractures and 86 cases of lateral instability of the ankle, including 36 feet with subacute lateral instability of the ankle and 50 feet with chronic lateral instability of the ankle. In diagnosing OCL, we used a combination of magnetic resonance imaging to evaluate the subchondral conditions and ankle arthroscopy to evaluate the chondral conditions. RESULTS: Of a total of 92 distal fibular fractures, 65 cases (70.7%) had OCL at the time of osteosynthesis and 27 did not (29.3%). Among the latter group, 2 developed OCL about 1 year after surgery. Of a total of 86 cases of lateral instability of the ankle, 35 (40.7%) had OCL. Among the subacute cases, 7 of 36 (19.4%) had OCL, versus 28 of 50 cases (56.0%) with chronic lateral instability of the ankle. CONCLUSIONS: Our study suggests that recurrent ankle sprains with remaining lateral instability and distal fibular fractures could be one of the causes of OCL of the ankle.

Adult↗

PubMed2003

Ultimate tensile strength of a Leeds-Keio/autograft ACL reconstruction utilizing PLLA tibial staple fixation.

An ovine model of anterior cruciate ligament reconstruction was utilized to evaluate the biomechanical and histological response of a polylactic acid tibial fixation staple (Gunze Ltd., Japan/Zimmer, Japan). This was performed in a comparison with metallic staples, currently utilized for this procedure. The prosthesis consisted of autograft combined with a Leeds-Keio (L-K) ligament. Early post-operative mobilization was followed by retrieval of specimens at 6, 12 and 24 weeks post-reconstruction. Evaluation of the mechanical characteristics of the graft reconstructions (tensile strength) showed no significant differences (P>0.05) between the staple types for each time period. The histological response to the polylactic acid staple was minimal over the time period studied, with no adverse tissue reactions observed. The mode of reconstruction failure was observed to change with time (P<0.05) presumably as the graft characteristics alter. Overall the absorbable staples performed at a comparable level with the metallic staples within the scope of the study.

Animals↗

PubMed2003

Second- and third-generation Omniflex modular femoral stem: results 3 to 8 years after surgery.

Primary cementless total hip arthroplasty (THA) using the Omniflex modular femoral stem was conducted on 73 hips in 70 patients. The arc deposition (AD)-type stem was used in 26 hips, and the hydroxyapatite (HA)-type stem was used in 47 hips. The mean follow-up period of patients in the AD group was 78 (range, 61-96) months and that of patients in the HA group was 52 (range, 36-61) months. Clinically, improvement in the Harris hip score occurred in all cases. Thigh pain was reported in 3 (11.5%) AD hips and in 1 (2.1%) HA hip. Radiologically, bone ingrowth fixation was seen in 88.5% of the AD group and in 97.9% of the HA group. No subtrochanteric stress shielding, stem migration of > 2 mm, or revision THA occurred. The second- and third- generation Omniflex stems are useful cementless devices resulting in favorable initial biologic fixation and little bone atrophy at mid-term follow-up.

Aged↗