Hirosuke Endo

PuraMatrix facilitates bone regeneration in bone defects of calvaria in mice.

Artificial bones have often used for bone regeneration due to their strength, but they cannot provide an adequate environment for cell penetration and settlement. We therefore attempted to explore various materials that may allow the cells to penetrate and engraft in bone defects. PuraMatrix™ is a self-assembling peptide scaffold that produces a nanoscale environment allowing both cellular penetration and engraftment. The objective of this study was to investigate the effect of PuraMatrix™ on bone regeneration in a mouse bone defect model of the calvaria. Matrigel™ was used as a control. The expression of bone-related genes (alkaline phosphatase, Runx2, and Osterix) in the PuraMatrix™-injected bone defects was stronger than that in the Matrigel™-injected defects. Soft X-ray radiographs revealed that bony bridges were clearly observed in the defects treated with PuraMatrix™, but not in the Matrigel™-treated defects. Notably, PuraMatrix™ treatment induced mature bone tissue while showing cortical bone medullary cavities. The area of newly formed bones at the site of the bone defects was 1.38-fold larger for PuraMatrix™ than Matrigel™. The strength of the regenerated bone was 1.72-fold higher for PuraMatrix™ (146.0 g) than for Matrigel™ (84.7 g). The present study demonstrated that PuraMatrix™ injection favorably induced functional bone regeneration.Artificial bones have often used for bone regeneration due to their strength, but they cannot provide an adequate environment for cell penetration and settlement. We therefore attempted to explore various materials that may allow the cells to penetrate and engraft in bone defects. PuraMatrix™ is a self-assembling peptide scaffold that produces a nanoscale environment allowing both cellular penetration and engraftment. The objective of this study was to investigate the effect of PuraMatrix™ on bone regeneration in a mouse bone defect model of the calvaria. Matrigel™ was used as a control. The expression of bone-related genes (alkaline phosphatase, Runx2, and Osterix) in the PuraMatrix™-injected bone defects was stronger than that in the Matrigel™-injected defects. Soft X-ray radiographs revealed that bony bridges were clearly observed in the defects treated with PuraMatrix™, but not in the Matrigel™-treated defects. Notably, PuraMatrix™ treatment induced mature bone tissue while showing cortical bone medullary cavities. The area of newly formed bones at the site of the bone defects was 1.38-fold larger for PuraMatrix™ than Matrigel™. The strength of the regenerated bone was 1.72-fold higher for PuraMatrix™ (146.0 g) than for Matrigel™ (84.7 g). The present study demonstrated that PuraMatrix™ injection favorably induced functional bone regeneration.

Bone repair by transplantation of hTERT-immortalized human mesenchymal stem cells in mice

Background. Human mesenchymal stem cells (hMSCs) are multipotent stem cells found in the adult bone marrow that have the capacity to differentiate into various mesenchymal cell types. The hMSCs may provide a potential therapy to restore damaged tissues or organs of mesenchymal origin; however, a drawback is their limited life span in vitro. Methods. We immortalized normal hMSCs with retrovirally transmitted human telomerase reverse transcriptase cDNA. One of the immortalized clones (YKNK-12) was established, and the biological characteristics were investigated in vitro and in vivo. Results. YKNK-12 cells were capable of differentiating adipocytes, osetoblasts, and chondrocytes. Osteogenically differentiated YKNK-12 cells produced significant levels of growth factors BMP4, BMP6, FGF6, FGF7, transforming growth factor-&bgr;1, and transforming growth factor-&bgr;3.. Microcomputer tomography T and soft X-ray assays showed an excellent calvarial bone healing in mice after transplantation of osteogenically differentiated YKNK-12 cells. These cells expressed human-specific osteocalcin and increased the gene expression of runt-related transcription factor 2, alkaline phosphatase, osteocalcin, and osterix in the bone regenerating area. YKNK-12 cell transplant corrected the bone defect without inducing any adverse effects. Conclusions. We conclude that hMSCs immortalized by transduction with human telomerase reverse transcriptase may provide an unlimited source of cells for therapeutic use in bone regeneration.

The Minimally Invasive Plate Osteosynthesis (MIPO) Technique with a Locking Compression Plate for Femoral Lengthening

A minimally invasive plate osteosynthesis technique using a locking compression plate (LCP) has been used widely in trauma cases. Its advantages are that the MIPO technique does not interfere with the fracture site and thus provides improved biological healing, and that the LCP has excellent angular stability. Its use in bone lengthening, however, has not been established. In such cases, it is desirable to shorten the external skeletal fixation period as much as possible. Here, the MIPO technique using an LCP was applied to femoral distraction osteogenesis in an attempt to shorten the external skeletal fixation period. For femoral lengthening, the MIPO technique was performed in 2 stages. Orthofix external fixators (Orthofix, England) were used to insert screws from the anterolateral side rather than from the lateral side of the femur for bone lengthening. When sufficient callus formation was detected postoperatively at the site of bone lengthening, and the absence of infection was ensured, limb draping was performed, including a whole external fixator, and then the MIPO technique was applied with an LCP.In 3 cases (5 limbs), the average duration of external skeletal fixation was 134 days, the average external-fixation index was 24 days/cm, and the average consolidation index was 22 days/cm. The MIPO technique using an LCP made it possible to shorten the external skeletal fixation-wearing period in femoral lengthening.

Gait characteristics after limb-sparing surgery with sciatic nerve resection: A report of two cases

Limb‐sparing surgery may be considered for the treatment of soft-tissue sarcoma even when resection of a major neurovascular bundle is necessary to achieve a satisfactory surgical margin1,2. Function of an upper extremity with loss of one major nerve is often superior to function with use of a prosthesis after amputation3. In the lower extremity, limb‐sparing surgery may be considered even when the sciatic nerve must be resected because of tumor involvement. Resection of the sciatic nerve results in a sensory loss distal to the knee and motor dysfunction of the knee, foot, and ankle. However, an analysis of functional loss after sciatic nerve resection for the treatment of soft-tissue sarcoma has been reported only once to our knowledge4. We treated two patients with a soft-tissue sarcoma with a limb‐sparing procedure that included resection of the sciatic nerve. During rehabilitation, both patients walked very slowly with excessive lateral displacement of the trunk along the line of progression. Very slight improvement in their gait was noted at the two and five-year follow‐up examinations. We assessed walking function and gait characteristics of the two patients with use of a nonparametric objective evaluation system and a subjective gait analysis technique to obtain quantitative measures of functional loss5‐8. The results were compared with those of patients with a hip disarticulation who used a prosthesis and with the findings in healthy individuals. A fifty‐one‐year‐old man (Case 1) and a twenty-six-year‐old woman (Case 2) had a limb‐sparing operation with sciatic nerve resection. Both patients had a malignant peripheral nerve-sheath tumor that developed in the sciatic nerve in the proximal half of the posterior aspect of the thigh. The surgical stage according to the Musculoskeletal Tumor Society Classification9 was IIB in each patient. Wide resection …

Calcar Femorale in Patients with Osteoarthritis of the Hip Secondary to Developmental Dysplasia

Background We investigated whether the calcar femorale, a cortical septum in the region of the lesser trochanter of the femur, correlates with results of femoral stem implantation in patients with osteoarthritis of the hip secondary to developmental dysplasia using computed tomography. Methods This retrospective study included 277 hips (41 males and 236 females; age, 37 to 92 years) of patients who had presented to Okayama Medical Center with hip pain. Of these, a total of 219 hips (31 males and 188 females) had previously undergone total hip arthroplasty. According to the Crowe classification, 147 hips were classified as Crowe grade I, 72 hips as Crowe grade II–IV, and 58 hips as normal. Results The calcar femorale was identified in 267 hips (96.4%). The calcar femorale was significantly shorter and more anteverted in Crowe grade II–IV hips than in Crowe grade I or normal hips. Significant differences in the shape of the calcar femorale were found according to the severity of hip deformity. Three stem designs were analyzed: single-wedge (59 hips), double-wedge metaphyseal filling (147 hips), and modular (13 hips). Single-wedge stems were inserted more parallel to the calcar femorale rather than femoral neck anteversion, while other types of stems scraped the calcar femorale. Conclusions The angle of the calcar femorale differs according to the severity of hip deformity, and the calcar femorale might thus serve as a more useful reference for stem insertion than femoral neck anteversion in total hip arthroplasty using a single-wedge stem.

Combination Therapy with Continuous Three-in-One Femoral Nerve Block and Periarticular Multimodal Drug Infiltration after Total Hip Arthroplasty

Background. Various postoperative pain relief modalities, including continuous femoral nerve block (CFNB), local infiltration analgesia (LIA), and combination therapy, have been reported for total knee arthroplasty. However, no studies have compared CFNB with LIA for total hip arthroplasty (THA). The aim of this study was to compare the efficacy of CFNB versus LIA after THA. Methods. We retrospectively reviewed the postoperative outcomes of 93 THA patients (20 men, 73 women; mean age 69.2 years). Patients were divided into three groups according to postoperative analgesic technique: CFNB, LIA, or combined CFNB+LIA. We measured the following postoperative outcome parameters: visual analog scale (VAS) for pain at rest, supplemental analgesia, side effects, mobilization, length of hospital stay, and Harris Hip Score (HHS). Results. The CFNB+LIA group had significantly lower VAS pain scores than the CFNB and LIA groups on postoperative day 1. There were no significant differences among the three groups in use of supplemental analgesia, side effects, mobilization, length of hospital stay, or HHS at 3 months after THA. Conclusions. Although there were no clinically significant differences in outcomes among the three groups, combination therapy with CFNB and LIA provided better pain relief after THA than CFNB or LIA alone, with few side effects.

Knee pain in a 16-year-old girl

345 A 16-year-old girl had right knee pain for 1 year. The pain gradually increased for a few months before presentation, particularly when the patient moved her knee. She had been treated with nonsteroidal antiinflammatory drugs by a local physician, but the pain continued. The patient denied having any history of trauma, fever, chills, or weight changes. Her medical history was unremarkable. Physical examination revealed focal tenderness on the patella. There were no palpable masses, soft tissue swelling, or local heat. The patient had full range of motion (ROM) of the knee, but suffered pain at the patellofemoral joint in the full flexion position. The McMurray’s test was negative. Laboratory values included normal serum chemistry, an erythrocyte sedimentation rate of 16 mm per hour, with a hemoglobin of 14 g/dL, and a leukocyte count of 7200 /uL. Plain radiographs,99m Technetium-hydroxymethylene diphosphonate (99mTc-HMDP), computed tomography (CT), and magnetic resonance imaging (MRI) scans are shown (Fig 1–4). SECTION III REGULAR AND SPECIAL FEATURES

Microgeodic Disease Affecting the Fingers and Toes in Childhood: A Case Report

Microgeodic disease is a disease of unknown etiology that affects the fingers and toes of children, with ≥ 90% of cases involving the fingers alone. We present a rare case of microgeodic disease affecting an index finger and two toes simultaneously in a 7-year-old girl. X-ray and magnetic resonance imaging (MRI) showed multiple small areas of osteolysis in the middle phalanges of the left index finger, hallux, and second toe. Microgeodic disease was diagnosed from X-ray and MRI findings, and conservative therapy involving rest and avoidance of cold stimuli was provided. Although pathological fractures occurred in the course of conservative treatment, the affected finger healed under splinting without any deformity of the finger.

Follow-up Study After Corrective Imhäuser Intertrochanteric Osteotomy for Slipped Capital Femoral Epiphysis

We investigated 28 hips in 26 patients with slipped capital femoral epiphysis who were treated by the Imhauser intertrochanteric osteotomy, with subsequent removal of implants. The mean age at operation was 13 years, and the mean age at the time of the final follow-up was 19 years. The physeal stability was unstable for 15 hips and stable for 13. Posterior tilting angle (PTA) ranged from 33° to 72° before operation. PTA became restored to within the allowable range of up to 30° in all patients. The limitation of range of motion completely resolved in all patients, and none had necrosis of the femoral head postoperatively. There was a mean reduction in leg length by 0.7 cm. Four patients had a fracture due to bone fragility from longterm traction and bed rest. Chondrolysis developed in only 1 male classified as an unstable case with an unstable classified as unstable. The Imhauser treatment system for mild to severe cases may be said to be reasonable in that the physeal stability is rendered stable by traction and then the PTA is reduced to 30° or less by osteotomy to lessen the severity to mild. So, satisfactory results were obtained both clinically and roentgenographically in short- or midterm outcome.