Treatment of Acute Achilles Tendon Rupture.

There is no clear consensus on the optimal treatment of acute Achilles tendon rupture. Recently, studies have demonstrated the critical role of functional rehabilitation in the treatment of ruptured Achilles tendons. Hence, conservative treatment is preferred by a growing number of surgeons seeking to treat the condition without the risk of complications from surgery. However, operative treatment is still considered as a more reliable treatment option for acute Achilles tendon rupture. In this review article, we provide an overview of recent treatment strategies for acute rupture of the Achilles tendon.

Results of Simple Conservative Treatment of Midfoot Charcot Arthropathy.

BACKGROUND: Traditionally, conservative management with an offloading orthosis, such as total contact cast (TCC), has been the standard of care for midfoot Charcot arthropathy. Considering complications of TCC and surgery, we treated midfoot Charcot arthropathy without TCC in our patients. The purpose of this study was to report clinical and radiological outcomes of conservative management of midfoot Charcot arthropathy. METHODS: A total of 34 patients (38 feet) who were diagnosed as having midfoot Charcot arthropathy between 2006 and 2014 were included. Patients started full weight bearing ambulation in a hard-soled shoe immediately after diagnosis. Outcomes such as progression of arch collapse, bony prominence, ulcer occurrence, limb amputation, and changes in Charcot stage were evaluated. RESULTS: Of 38 feet, arch collapse was observed in four while progression of bottom bump of the midfoot was observed in five feet. Foot ulcers related to bony bumps were found in two feet. CONCLUSIONS: Conservative treatment without restriction of ambulation is recommended for midfoot Charcot arthropathy because it is rarely progressive, unlike hindfoot-ankle arthropathy. In some cases, simple bumpectomy can be required to prevent catastrophic infection.

Differences in lower quarter Y-balance test with player position and ankle injuries in professional baseball players.

PURPOSE: Although there has been research about the correlation between ankle injury and Y-balance test (YBT) conducted in other sports, there has been a lack of research on the correlation between ankle injury among baseball players and YBT scores or on differences in scores according to baseball positions. This study focused on professional baseball players as its subjects with the aims of analyzing the correlation between YBT and ankle injury and assessing differences in YBT between baseball positions. METHODS: Age, height, weight, body mass index, and spine malleolar distance of 42 professional baseball players were measured. YBT measurements were performed using each foot in three distinct directions. YBT normalized reach distances, composite score, and reach asymmetry were analyzed. RESULTS: The mean right posteromedial normalized reach distances for the player positions were significantly different between the pitchers (107.7%) and infielders (113.7%) ( p = 0.028). For the composite score, the difference between the pitchers (92.3%) and infielders (95.0%) was statistically significant ( p = 0.048). The anterior reach asymmetry was larger in the injured group than in the noninjured group ( p = 0.041). CONCLUSION: This study shows that YBT can be used as a way of evaluating the injury of baseball players. It also shows the reference value of YBT according to position in professional baseball players. This study could be useful for the treatment of ankle injury of baseball players. Level of evidence: Level 3.

Results of tenorrhaphy with early rehabilitation for acute tear of Achilles tendon.

BACKGROUND: For the treatment of acute Achilles tendon rupture, early rehabilitation after surgical repair is believed to be a useful method. The purpose of this study was to evaluate the outcome of open tenorrhaphy followed by early rehabilitation. METHODS: A total of 112 patients who underwent open repair and early rehabilitation for acute Achilles tendon rupture from January 2003 to March 2015 were retrospectively reviewed. These 112 patients (80 men, 32 women) had an average age of 43.1 years (22-62 years), and the mean follow-up period was 91.8 months (12-171 months). A short leg cast was applied postoperatively for an average of 16.5 days (12-20 days). The mean duration of bracing was 6.9 weeks (6-8 weeks). Each patient was assessed based on range of motion, single heel raising test, calf circumference compared to the contralateral limb, ability to return to previous activity, the Arner-Lindholm scale, and the American orthopaedic foot and ankle society (AOFAS) hind foot scale. Isokinetic plantar flexion power was also checked. RESULTS: All patients were fully satisfied (AOFAS ≥ 90) with the treatment results, and 96 patients were able to return to their previous athletic activities. As assessed by the Arner-Lindholm scale, 103 cases were rated as excellent and the other 9 cases were rated as good. At the 1-year follow-up period, single heel raise and hopping was possible in every patient. Compared to the contralateral side, 10 subjects (8.9%) had minor limitation of dorsiflexion motion, and an average of 1.6 cm calf circumference difference without functional disabilities. There were no major complications such as re-rupture, nerve injury, or infection. CONCLUSION: For acute Achilles tendon ruptures, open surgical repair with optimal length restoration, followed by earlier rehabilitation results in good functional outcomes and a successful return to pre-injury levels of physical activity without major complications. LEVEL OF EVIDENCE: Level IV.

Prognosis of Single Spinal Metastatic Tumors: Predictive Value of the Spinal Instability Neoplastic Score System for Spinal Adverse Events.

STUDY DESIGN: This was a retrospective cohort study. PURPOSE: We evaluated the predictive value of the Spinal Instability Neoplastic Score (SINS) system for spinal adverse events (SAEs) in patients with single spinal metastatic tumor. OVERVIEW OF LITERATURE: The SINS system was developed to assess spinal instability in patients with single metastatic spinal tumor. However, the system's potential predictive value for SAEs has been partially studied. METHODS: This system was applied to a retrospective cohort of 78 patients with single spinal metastatic tumors. The patients underwent surgical treatment and were postoperatively followed up for at least 2 years or until death. The attribution of each score and total SINS to SAE (vertebral compression fracture [VCF] and spinal cord compression [SCC]) occurrence was assessed using the Cox proportional hazards model. RESULTS: SAEs occurred on average 7 months after diagnosis of spinal metastasis. The mean survival rate post diagnosis was 43 months. Multivariate analysis using the Cox proportional hazards model revealed that the pain (p =0.029) and spinal alignment (p =0.001) scores were significantly related to VCF occurrence, whereas the pain (p =0.008) and posterolateral involvement (p =0.009) scores were related to SCC occurrence. CONCLUSIONS: Among the components of the SINS system, while pain and spinal alignment showed a significant association with VCF occurrence, pain and posterolateral involvement showed association with SCC occurrence.

Sarcopenia increases the risk for mortality in patients who undergo amputation for diabetic foot.

BACKGROUND: Although there have been reports that diabetes affects the prevalence of sarcopenia, no studies have examined the relationship between sarcopenia and mortality in patients undergoing leg amputation. The purpose of this study is to determine whether sarcopenia affects the mortality rate of patients undergoing diabetic foot amputation. METHODS: From among patients who underwent limb amputation for diabetes complications, this study included 167 patients who underwent abdominal CT within 1 year of amputation. We defined sarcopenia using sex-specific cut-off points for the L3 skeletal muscle index. The 5-year survival rate was analyzed. All patients were divided into two groups and compared according to the presence of sarcopenia. The mortality rate according to sarcopenia was assessed via the Kaplan-Meier method and log-rank test. Uni- and multivariate Cox regression analyses evaluated factors associated with survival rate. RESULTS: Among the total of 167 patients, the overall 5-year mortality rate was 52.7%. Of the 112 patients with sarcopenia, the 5-year mortality rate was 60.7%. Of the 55 patients without sarcopenia, the 5-year mortality rate was 36.4%. Kaplan-Meier analysis showed a high mortality of the sarcopenia group in the univariate (p = 0.016) and multivariate (p = 0.047) analysis. CONCLUSIONS: Our study is the first to analyze the relationship between diabetic amputation and sarcopenia. Sarcopenia increases the risk of mortality in patients who undergo amputation for diabetic foot. Therefore, patients with diabetes should be careful to prevent sarcopenia with enough regular exercise as well as prevent diabetic foot disease.

Osteochondral lesions of the talus.

Background and purpose - The frequency of progression of osteoarthritis and persistence of symptoms in untreated osteochondral lesion of the talus (OCL) is not well known. We report the outcome of a nonoperative treatment for symptomatic OCL. Patients and methods - This study included 142 patients with OCLs from 2003 to 2013. The patients did not undergo immobilization and had no restrictions of physical activities. The mean follow-up time was 6 (3-10) years. Initial MRI and CT confirmed OCL and showed lesion size, location, and stage of the lesion. Progression of osteoarthritis was evaluated by standing radiographs. In 83 patients, CT was performed at the final follow-up for analyses of the lesion size. We surveyed patients for limitations of sports activity, and Visual Analogue Scales (VAS), AOFAS, and SF-36 were assessed. Results - No patients had progression of osteoarthritis. The lesion size as determined by CT did not change in 69/83 patients, decreased in 5, and increased in 9. The mean VAS score of the 142 patients decreased from 3.8 to 0.9 (p < 0.001), the mean AOFAS ankle-hindfoot score increased from 86 to 93 (p < 0.001), and the mean SF-36 score increased from 52 to 72 (p < 0.001). Only 9 patients reported limitations of sports activity. The size and location of the lesion did not correlate with any of the outcome scores. Interpretation - Nonoperative treatment can be considered a good option for patients with OCL.

Combined Autograft and Bone Cement for Painful Chondroblastoma: A Case Report.

Chondroblastomas of the talus can lead to joint collapse and are often treated using curettage and bone grafting. In the present report, we describe the case of a 19-year-old female with a large chondroblastoma of the talus associated with a secondary aneurysmal cyst. We treated the large cartilage lesion, which involved most of the talus, with an iliac bone graft combined with bone cement to fill the large bone defect and preserve the subchondral bone of the articular surface of the dome of the talus.

Inter-segmental motions of the foot: differences between younger and older healthy adult females.

BACKGROUND: Although accumulative evidence exists that support the applicability of multi-segmental foot models (MFMs) in evaluating foot motion in various pathologic conditions, little is known of the effect of aging on inter-segmental foot motion. The objective of this study was to evaluate differences in inter-segmental motion of the foot between older and younger adult healthy females during gait using a MFM with 15-marker set. METHODS: One hundred symptom-free females, who had no radiographic evidence of osteoarthritis, were evaluated using MFM with 15-marker set. They were divided into young (n = 50, 20-35 years old) and old (n = 50, 60-69 years old) groups. Coefficients of multiple correlations were evaluated to assess the similarity of kinematic curve. Inter-segmental angles (hindfoot, forefoot, and hallux) were calculated at each gait phase. To evaluate the effect of gait speed on intersegmental foot motion, subgroup analysis was performed according to the similar speed of walking. RESULTS: Kinematic curves showed good or excellent similarity in most parameters. Range of motion in the sagittal (p < 0.001) and transverse (p = 0.001) plane of the hallux, and sagittal (p = 0.023) plane of the forefoot was lower in older females. The dorsiflexion (p = 0.001) of the hallux at terminal stance and pre-swing phases was significantly lower in older females. When we compared young and older females with similar speed, these differences remained. CONCLUSIONS: Although the overall kinematic pattern was similar between young and older females, reduced range of inter-segmental motion was observed in the older group. Our results suggest that age-related changes need to be considered in studies evaluating inter-segmental motion of the foot.

Selective Fasciotomy for Chronic Exertional Compartment Syndrome Detected With Exercise Magnetic Resonance Imaging.

Chronic exertional compartment syndrome that is refractory to conservative management should be treated with surgical fasciotomy. However, owing to the limitations of intracompartmental needle manometry in reaching a definite diagnosis, the appropriate timing for fasciotomy and on which compartment remain unclear. The authors report the case of a 22-year-old male military cadet who reported pain in his left calf when running or walking for long distances. The pain was located at the lateral aspect of the calf, from the mid-calf level to the ankle. At another hospital, nonenhanced magnetic resonance imaging had been performed, which showed no considerable abnormality. The authors used exercise magnetic resonance imaging to diagnose chronic exertional compartment syndrome. They performed selective fasciotomy on the compartment that showed a high signal intensity. As a military cadet, the patient was required to jog for more than an hour per day and perform strenuous muscle exercises. He reported that he did not have calf pain or discomfort during such activities 13 months postoperatively. The authors obtained a follow-up exercise magnetic resonance image. Compared with the preoperative magnetic resonance image, the follow-up exercise magnetic resonance image did not show high signal intensity at the lateral compartment. Exercise magnetic resonance imaging is useful in confirming the diagnosis of chronic exertional compartment syndrome and enables the performance of selective fasciotomy on the affected compartment. [Orthopedics. 2017; 40(6):e1099-e1102.].

Platelet-Derived Growth Factor Receptor-Positive Pericytic Cells of White Adipose Tissue from Critical Limb Ischemia Patients Display Mesenchymal Stem Cell-Like Properties.

BACKGROUND: The pericytes in the blood vessel wall have recently been identified to be important in regulating vascular formation, stabilization, remodeling, and function. We isolated and identified pericyte-like platelet-derived growth factor receptor beta-positive (PDGFRß+) cells from the stromal vascular fraction (SVF) of adipose tissue from critical limb ischemia (CLI) patients and investigated their potential as a reliable source of stem cells for cell-based therapy. METHODS: De-identified subcutaneous fat tissues were harvested after amputation in CLI patients. Freshly isolated SVF cells and culture-expanded adipose-derived stem cells (ADSCs) were quantified using flow cytometry. A matrigel tube formation assay and multi-lineage differentiation were performed to assess pericytic and mesenchymal stem cell (MSC)-like characteristics of PDGFRß+ ADSCs. RESULTS: PDGFRß+ cells were located in the pericytic area of various sizes of blood vessels and coexpressed mesenchymal stem cell markers. PDGFRß+ cells in freshly isolated SVF cells expressed a higher level of stem cell markers (CD34 and CXCR4) and mesenchymal markers (CD13, CD44, CD54, and CD90) than PDGFRß- cells. In vitro expansion of PDGFRß+ cells resulted in enrichment of the perivascular mesenchymal stem-like (PDGFRß+/CD90+/CD45-/CD31-) cell fractions. The Matrigel tube formation assay revealed that PDGFRß+ cells were located in the peritubular area. CONCLUSIONS: PDGFRß+ ADSCs cells demonstrated a good multilineage differentiation potential. Pericyte-like PDGFRß+ cells from the SVF of adipose tissue from CLI patients had MSC-like characteristics and could be amplified by in vitro culture with preservation of their cell characteristics. We believe PDGFRß+ cells in the SVF of adipose tissue can be used as a reliable source of stem cells even in CLI patients.

Comparison of Multisegmental Foot and Ankle Motion Between Total Ankle Replacement and Ankle Arthrodesis in Adults.

BACKGROUND: Total ankle replacement (TAR) and ankle arthrodesis (AA) are usually performed for severe ankle arthritis. We compared postoperative foot segmental motion during gait in patients treated with TAR and AA. METHODS: Gait analysis was performed in 17 and 7 patients undergoing TAR and AA, respectively. Subjects were evaluated using a 3-dimensional multisegmental foot model with 15 markers. Temporal gait parameters were calculated. The maximum and minimum values and the differences in hallux, forefoot, hindfoot, and arch in 3 planes (sagittal, coronal, transverse) were compared between the 2 groups. One hundred healthy adults were evaluated as a control. RESULTS: Gait speed was faster in the TAR ( P = .028). On analysis of foot and ankle segmental motion, the range of hindfoot sagittal motion was significantly greater in the TAR (15.1 vs 10.2 degrees in AA; P = .004). The main component of motion increase was hindfoot dorsiflexion (12.3 and 8.6 degrees). The range of forefoot sagittal motion was greater in the TAR (9.3 vs 5.8 degrees in AA; P = .004). Maximum ankle power in the TAR (1.16) was significantly higher than 0.32 in AA; P = .008). However, the range of hindfoot and forefoot sagittal motion was decreased in both TAR and AA compared with the control group ( P = .000). CONCLUSION: Although biomechanical results of TAR and AA were not similar to those in the normal controls, joint motions in the TAR more closely matched normal values. Treatment decision making should involve considerations of the effect of surgery on the adjacent joints. LEVEL OF EVIDENCE: Level III, case-control study.

Diabetic Foot Complications Despite Successful Pancreas Transplantation.

BACKGROUND: It is known that successful pancreas transplantation enables patients with diabetes to maintain a normal glucose level without insulin and reduces diabetes-related complications. However, we have little information about the foot-specific morbidity in patients who have undergone successful pancreas transplantation. The purpose of this study was to investigate the prevalence and predisposing factors for foot complications after successful pancreas transplantation. METHODS: This retrospective study included 218 patients (91 males, 127 females) who had undergone pancreas transplantation for diabetes. The mean age was 40.7 (range, 15-76) years. Diabetes type, transplantation type, body mass index, and diabetes duration before transplantation were confirmed. After pancreas transplantation, the occurrence and duration of foot and ankle complications were assessed. RESULTS: Twenty-two patients (10.1%) had diabetic foot complications. Fifteen patients (6.9%) had diabetic foot ulcer and 7 patients (3.2%) had Charcot arthropathy. Three patients had both diabetic foot ulcer and Charcot arthropathy. Three insufficiency fractures (1.4%) were included. Mean time of complications after transplantation was 18.5 (range, 2-77) months. Creatinine level 1 year after surgery was higher in the complication group rather than the noncomplication group ( P = .02). CONCLUSION: Complications of the foot and ankle still occurred following pancreas transplantation in patients with diabetes. LEVEL OF EVIDENCE: Level III, comparative study.

Sex differences in knee joint loading: Cross-sectional study in geriatric population.

This study investigated sex differences in knee biomechanics and investigated determinants for difference in a geriatric population. Age-matched healthy volunteers (42 males and 42 females, average age 65 years) without knee OA were included in the study. Subjects underwent physical examination on their knee and standing full-limb radiography for anthropometric measurements. Linear, kinetic, and kinematic parameters were compared using a three-dimensional, 12-camera motion capture system. Gait parameters were evaluated and determinants for sex difference were evaluated with multiple regression analysis. Females had a higher peak knee adduction moment (KAM) during gait (p = 0.004). Females had relatively wider pelvis and narrower step width (both p < 0.001). However, coronal knee alignment was not significantly different between the sexes. Multiple regression analysis revealed that coronal alignment (b = 0.014, p < 0.001), step width (b = -0.010, p = 0.011), and pelvic width/height ratio (b = 1.703, p = 0.046) were significant determinants of peak KAM. Because coronal alignment was not different between the sexes, narrow step width and high pelvic width/height ratio of female were the main contributors to higher peak KAM in females. Sex differences in knee biomechanics were present in the geriatric population. Increased mechanical loading on the female knee, which was associated with narrow step width and wide pelvis, may play an important role in future development and progression of OA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1283-1289, 2017.

Inter-segmental motions of the foot in healthy adults: Gender difference.

BACKGROUND: Multi-segment Foot Models (MFM) have increased in use for both clinical and research applications; however, little is known about the gender differences of inter-segmental motions within the foot and ankle during gait. The objectives of this study were to analyze the gender differences of inter-segmental foot motion during gait in healthy young adults using a MFM with a 15-marker set. METHODS: One hundred healthy adults (50 males, 50 females) between 20 and 35 years of age who had normal function and no radiographic abnormality, were evaluated. Inter-segmental angles (ISA) (hindfoot, forefoot, and hallux) were calculated at each time point. The ISAs at specific phases of the gait cycle, the change in ISAs between the phases, and the range of motion for each ISA across the entire gait cycle were compared between genders. RESULTS: The kinematic curve of the inter-segmental foot motions showed a characteristic pattern during the whole gait cycle. Although the hallux of female was aligned in a more valgus angulation during gait, the overall patterns of the inter-segmental foot motions were quite similar for both genders. Most differences in the inter-segmental foot motions between men and women were observed in the range of motion. Considering the stance phase of gait-cycle, the range of motion in the sagittal and transverse plane of the hindfoot was greater in females than in males. The sagittal range of motion of the hallux was also greater in females, mainly due to higher plantar flexion. CONCLUSIONS: The gender differences of the inter-segmental foot motion were investigated during gait in healthy young adults using a MFM with a 15-marker set. Females had a larger range of motion in the sagittal plane of the hallux and in the sagittal and transverse plane of the hindfoot.

Debridement and Functional Rehabilitation for Achilles Tendon Infection Following Tendon Repair.

BACKGROUND: An infected Achilles tendon after tendon repair is particularly difficult to treat because of the poor vascularity of the tendon as well as the thin surrounding soft tissue. For treatment of an infected Achilles tendon following tendon repair, we first focused on complete debridement and then promoted fibrous scar healing of the Achilles tendon using functional treatment. METHODS: We retrospectively reviewed all of the medical records of 15 tertiary referral patients with postoperative infection of the Achilles tendon occurring between 2007 and 2012. The mean follow-up time was 33 months (range, 22 to 97 months). The infected tissue and the necrotic tendon were debrided, and the ankle was placed in a short leg splint for 2 weeks. The splint was then replaced with an ankle brace for the next 4 weeks. Partial weight-bearing was allowed immediately, and full weight-bearing was allowed at 2 weeks postoperatively. We assessed and recorded the physical parameters such as the range of motion, calf circumference, ability to perform a single-limb heel rise, patient satisfaction, and Arner-Lindholm scale. Laboratory tests, postoperative ultrasonography, and isokinetic plantar flexion power tests were also performed. RESULTS: At a mean time of 17 days (range, 8 to 30 days) after debridement, infection signs such as discharge from the wound, redness, and local warmth resolved. The wound had healed and the stitches were removed at a mean of 17 days following the wound repair. At the time of the latest follow-up, there were no signs of active infection. Achilles tendon continuity recovered in all patients by fibrous scar healing. Compared with the contralateral side, there was no difference in the ankle range of motion in 8 patients. According to the Arner-Lindholm scale, 9 of the 15 results were excellent and 6 were good. Ten patients were able to perform a single-limb heel rise. Eleven of 15 patients returned to their pre-injury recreational activities. Diffuse homogeneous echotexture of the Achilles tendon with continuity was observed on the ultrasonographic examination. CONCLUSIONS: In this retrospective series, radical debridement, combined with antibiotic therapy and functional rehabilitation, was successful in eradicating infection and maintaining function in patients with postoperative infection following Achilles tendon repair. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Foot and Ankle Function at Maturity After Ilizarov Treatment for Atrophic-Type Congenital Pseudarthrosis of the Tibia: A Comprehensive Outcome Comparison with Normal Controls.

BACKGROUND: The purpose of this study was to evaluate clinical outcomes and the biomechanical function of the foot and ankle at skeletal maturity of patients treated for atrophic-type congenital pseudarthrosis of the tibia (CPT) compared with healthy young adult controls. METHODS: Twenty-four patients (mean age of 19.1 years) who had undergone Ilizarov treatment for unilateral atrophic-type CPT were compared with twenty-four controls (mean age of 19.6 years). All participants were evaluated using validated outcome questionnaires, radiographs, physical examination, instrumented motion analysis including a multisegmental foot model, and pedobarographic measurement. RESULTS: Within the CPT group, the mean score of the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale was 89.9 (range, 76 to 100), and the mean score of the Oxford Ankle Foot Questionnaire (OAFQ) was 42.8 (range, 15 to 60). Motion analysis and pedobarographic measurement showed differences in biomechanical function of the foot and ankle on the side affected by CPT: a slower walking speed due to the short stride length; decreased dorsiflexion in hallux motion; increased hindfoot pronation in the presence of forefoot supination; diminished ankle push-off power; delayed time to heel-rise; and decreased forefoot pressure relative to hindfoot pressure. However, sagittal motion of the hindfoot and forefoot on the affected side was relatively well preserved. Subgroup analysis demonstrated no significant differences in terms of clinical outcome scores and most biomechanical parameters between the tibiofibular synostosis group and the intact-fibula group. CONCLUSIONS: Children with atrophic-type CPT can obtain satisfactory foot and ankle function at maturity after successful Ilizarov treatment. Early stabilization of the ankle mortise by fibular stabilization and preservation of ankle mobility during and after treatment is thought to be crucial to maintaining function of the ankle in patients with CPT. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Quantitative Assessment of Foot Blood Flow by Using Dynamic Volume Perfusion CT Technique: A Feasibility Study.

PURPOSE: To demonstrate the feasibility of foot blood flow measurement by using dynamic volume perfusion computed tomographic (CT) technique with the upslope method in an animal experiment and a human study. MATERIALS AND METHODS: The human study was approved by the institutional review board, and written informed consent was obtained from all patients. The animal study was approved by the research animal care and use committee. A perfusion CT experiment was first performed by using rabbits. A color-coded perfusion map was reconstructed by using in-house perfusion analysis software based on the upslope method, and the measured blood flow on the map was compared with the reference standard microsphere method by using correlation analysis. A total of 17 perfusion CT sessions were then performed (a) once in five human patients and (b) twice (before and after endovascular revascularization) in six human patients. Perfusion maps of blood flow were reconstructed and analyzed. The Wilcoxon signed rank test was used to prove significant differences in blood flow before and after treatment. RESULTS: The animal experiment demonstrated a strong correlation (R(2) = 0.965) in blood flow between perfusion CT and the microsphere method. Perfusion maps were obtained successfully in 16 human clinical sessions (94%) with the use of 32 mL of contrast medium and an effective radiation dose of 0.31 mSv (k factor for the ankle, 0.0002). The plantar dermis showed the highest blood flow among all anatomic structures of the foot, including muscle, subcutaneous tissue, tendon, and bone. After a successful revascularization procedure, the blood flow of the plantar dermis increased by 153% (P = .031). The interpretations of the color-coded perfusion map correlated well with the clinical and angiographic findings. CONCLUSION: Perfusion CT could be used to measure foot blood flow in both animals and humans. It can be a useful modality for the diagnosis of peripheral arterial disease by providing quantitative information on foot perfusion status.

Demineralized Bone Matrix Injection in Consolidation Phase Enhances Bone Regeneration in Distraction Osteogenesis via Endochondral Bone Formation.

BACKGROUND: Distraction osteogenesis (DO) is a promising tool for bone and tissue regeneration. However, prolonged healing time remains a major problem. Various materials including cells, cytokines, and growth factors have been used in an attempt to enhance bone formation. We examined the effect of percutaneous injection of demineralized bone matrix (DBM) during the consolidation phase on bone regeneration after distraction. METHODS: The immature rabbit tibial DO model (20 mm length-gain) was used. Twenty-eight animals received DBM 100 mg percutaneously at the end of distraction. Another 22 animals were left without further procedure (control). Plain radiographs were taken every week. Postmortem bone dual-energy X-ray absorptiometry and micro-computed tomography (micro-CT) studies were performed at the third and sixth weeks of the consolidation period and histological analysis was performed. RESULTS: The regenerate bone mineral density was higher in the DBM group when compared with that in the saline injection control group at the third week postdistraction. Quantitative analysis using micro-CT revealed larger trabecular bone volume, higher trabecular number, and less trabecular separation in the DBM group than in the saline injection control group. Cross-sectional area and cortical thickness at the sixth week postdistraction, assessed using micro-CT, were greater in the regenerates of the DBM group compared with the control group. Histological evaluation revealed higher trabecular bone volume and trabecular number in the regenerate of the DBM group. New bone formation was apparently enhanced, via endochondral ossification, at the site and in the vicinity of the injected DBM. DBM was absorbed slowly, but it remained until the sixth postoperative week after injection. CONCLUSIONS: DBM administration into the distraction gap at the end of the distraction period resulted in a significantly greater regenerate bone area, trabecular number, and cortical thickness in the rabbit tibial DO model. These data suggest that percutaneous DBM administration at the end of the distraction period or in the early consolidation period may stimulate regenerate bone formation and consolidation in a clinical situation with delayed bone healing during DO.