Distal Tibial Metaphysis Research Articles

Parathyroid hormone-related protein (107-111) improves the bone regeneration potential of gelatin–glutaraldehyde biopolymer-coated hydroxyapatite

Biopolymer-coated nanocrystalline hydroxyapatite (HA) made as macroporous foams which are degradable and flexible are promising candidates as orthopaedic implants. The C-terminal (107-111) epitope of parathyroid hormone-related protein (PTHrP) exhibits osteogenic properties. The main aim of this study was to evaluate whether PTHrP (107-111) loading into gelatin–glutaraldehyde biopolymer-coated HA (HAGlu) scaffolds would produce an optimal biomaterial for tissue engineering applications. HAGlu scaffolds with and without PTHrP (107-111) were implanted into a cavitary defect performed in both distal tibial metaphysis of adult rats. Animals were sacrificed after 4weeks for histological, microcomputerized tomography and gene expression analysis of the callus. At this time, bone healing occurred only in the presence of PTHrP (107-111)-containing HAGlu implant, related to an increase in bone volume/tissue volume and trabecular thickness, cortical thickness and gene expression of osteocalcin and vascular cell adhesion molecule 1, but a decreased gene expression of Wnt inhibitors, SOST and dickkopf homolog 1. The autonomous osteogenic effect of the PTHrP (107-111)-loaded HAGlu scaffolds was confirmed in mouse and human osteoblastic cell cultures. Our findings demonstrate the advantage of loading PTHrP (107-111) into degradable HAGlu scaffolds for achieving an optimal biomaterial that is promising for low load bearing clinical applications.

Ankle fusion with centralisation of the fibula after distal tibia bone tumour resection

BackgroundManagement of distal tibial tumours with limb salvage surgery poses a challenge for the orthopaedic surgeon. This study was done to evaluate the results of fibular centralisation as a technique to reconstruct defects that occurred after resection at this site.Materials and methodsNine patients with a mean age of 23.2 years (range 17–34) with diagnosis of osteosarcoma in four patients, Ewing’s sarcoma in two, giant cell tumour in two and chondrosarcoma in one patient underwent surgical treatment for tumour in the distal tibia. All patients had wide resection of the tumour and ankle arthrodesis with centralisation of the fibula. Patients were assessed clinico-radiologically for bone union, infection and complications. The final functional outcome was estimated according to Musculoskeletal Tumor Society (MSTS) scores.ResultsThe mean age at the time of surgery was 23.2 years (17–34). There were five females and four males. The mean follow-up was 37 months (range 28–54 months). One of the patients with osteosarcoma had a recurrence a year after limb salvage surgery, underwent above-knee amputation, and died 18 months later due to metastasis. One patient developed leg length discrepancy. The mean MSTS score was 22.75 (range 17–27).ConclusionFibular centralisation is a durable reconstruction tool for defects of the distal tibial metaphysis with an acceptable functional outcome. It is an inexpensive and simple procedure, with a low rate of late complications, and reproducible results.Level of evidenceIV Retrospective case series.

Percutaneous Autologous Bone Marrow Injection in the Treatment of Distal Meta-diaphyseal Tibial Nonunions and Delayed Unions

To report the outcomes of percutaneous autologous bone marrow injection for nonunion or delayed union of the distal tibial metaphysis in patients with prior plating. Consecutive case series. Tertiary center. Eleven consecutive patients (aged 24-51 years) were referred to us with a nonunion or delayed union of the distal tibial metaphysis after open reduction and internal fixation (plates and screws) at the time of fracture. The average time from initial injury to nonunion or delayed union and bone marrow treatment was 8 months (range, 3-20 months). A total of 40-80 mL of bone marrow aspirated from the posterior iliac crest and injected in and around the nonunion or delayed union site under fluoroscopic guidance. Healing at the injury site was evaluated using clinical and radiographic criteria, including computed tomography. Measures included American Academy of Orthopaedic Surgeons Lower Limb Core Scale (LLCS), Brief Pain Inventory, and Short Form 12 Physical Component Summary. Nine of the 11 patients attained bony union within 6 months of bone marrow injection. Six of these 9 patients who were followed-up an average of 4.4 years (range, 1.3-8.2 years) after the injection reported significant (P < 0.05) improvements in Lower Limb Core Scale (59.9-89.7), pain intensity (2.9-1.7), pain interference (4.6-2.3), and Short Form 12 Physical Component Summary (29.5-46.6) and 5.6 years improvement in quality-adjusted life years. Percutaneous autologous bone marrow injection is a minimally invasive, safe, and inexpensive treatment option for distal metaphyseal tibial nonunions or delayed unions after internal fixation and should be considered when the retained hardware seems to be intact and stable. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Quantitative Assessment of the Yield of Osteoblastic Connective Tissue Progenitors in Bone Marrow Aspirate from the Iliac Crest, Tibia, and Calcaneus

It is well known that bone marrow aspirate from the iliac crest contains osteoblastic connective tissue progenitor cells. Alternative harvest sites in foot and ankle surgery include the distal aspect of the tibia and the calcaneus. To our knowledge, no previous studies have characterized the quality of bone marrow aspirate obtained from these alternative sites and compared the results with those of aspirate from the iliac crest. The goal of this study was to determine which anatomic location yields the highest number of osteoblastic progenitor cells. Forty patients were prospectively enrolled in the study, and separate bone marrow aspirate samples were harvested from the ipsilateral anterior iliac crest, distal tibial metaphysis, and calcaneal body. The aspirate was centrifuged to obtain a concentrate of nucleated cells, which were plated and grown in cell culture. Colonies that stained positive for alkaline phosphatase were counted to estimate the number of osteoblastic progenitor cells in the initial sample. The anatomic locations were compared. Clinical parameters (including sex, age, tobacco use, body mass index, and diabetes) were assessed as possible predictors of osteoblastic progenitor cell yield. Osteoblastic progenitor cells were found at each anatomic location. Bone marrow aspirate collected from the iliac crest had a higher mean concentration of osteoblastic progenitor cells compared with the distal aspect of the tibia or the calcaneus (p &lt; 0.0001). There was no significant difference in concentration between the tibia and the calcaneus (p = 0.063). Age, sex, tobacco use, and diabetes were not predictive of osteoblastic progenitor cell yield. Osteoblastic progenitor cells are available in the iliac crest, proximal aspect of the tibia, and calcaneus. However, the iliac crest provided the highest yield of osteoblastic progenitor cells. The study demonstrated that osteogenic progenitor cells are available in bone marrow aspirate harvested from the tibia or calcaneus as well as the iliac crest. All three sites are easily accessed, with a low risk of adverse events. However, larger volumes of aspirate may be needed from the tibia or calcaneus to approach the yield of cells from the iliac crest.

Ankle fractures have features of an osteoporotic fracture

We report the bone attenuation of ankle joint measured on computed tomography (CT) and the cause of injury in patients with ankle fractures. The results showed age- and gender-dependent low bone attenuation and low-energy trauma in elderly females, which suggest the osteoporotic features of ankle fractures. This study was performed to investigate the osteoporotic features of ankle fracture in terms of bone attenuation and cause of injury. One hundred ninety-four patients (mean age 51.0 years, standard deviation 15.8 years; 98 males and 96 females) with ankle fracture were included. All patients underwent CT examination, and causes of injury (high/low-energy trauma) were recorded. Mean bone attenuations of the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis were measured on CT images. Patients were divided into younger age (<50 years) and older age (≥50 years) groups, and mean bone attenuation and causes of injury were compared between the two groups in each gender. Proportion of low-energy trauma was higher in the older age group than in the younger age group, but the difference was only significant in female gender (p = 0.011). The older age group showed significantly lower bone attenuation in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis than the younger age group in both genders. The older age group showed more complex pattern of fractures than the younger age group. With increasing age, bone attenuations tended to decrease and the difference of bone attenuation between the genders tended to increase in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis. Ankle fracture had features of osteoporotic fracture that is characterized by age- and gender-dependent low bone attenuation. Ankle fracture should not be excluded from the clinical and research interest as well as from the benefit of osteoporosis management.

Distal tibial physeal bridge

We report on a case of a tension band plate and screw construct (Eight Plate) used over the anterior distal tibia in an 9-year-old girl in an attempt to induce recurvatum of the ankle joint to correct a recalcitrant equinus deformity. With growth of the distal tibial physis, the epiphyseal screw was drawn through the physis into the distal tibial metaphysis, resulting in the creation of a transphyseal bony bar. Caution should be exercised when attempting temporary hemiepiphyseodesis using a plate and screw construct in small epiphyses or in an osteopenic bone.

Severe lateral tibial bowing with short stature in two siblings—A provisionally novel syndrome

In this report, we describe two siblings with short stature and severe lateral tibial bowing. In the younger sibling, the bowing was bilateral, while in the older sib, it was unilateral. However, both showed bilateral abnormalities of the distal tibial epiphyses and growth plates. Pseudoarthrosis of the left distal tibial metaphysis and subsequent spontaneous resolution of the abnormality occurred in the younger sibling. The fibulas of both children were of normal diameter and were straight, except for the distal ends. Surgery has almost completely corrected the lower leg bowing in both patients. The type of tibial bowing seen in these children can be associated with a number of syndromes, such as neurofibromatosis type I, Weismann-Netter syndrome, and a variety of environmental caused disorders, such as vitamin D deficient rickets. However, the severity of the bowing present in our patients and the absence of other clinical features differentiates this condition from those reported in the literature. We posit that the condition in the children presented here represents an as yet undescribed syndrome, which is likely to be of genetic origin.

Injury to the Anterior Tibial System During Percutaneous Plating of a Proximal Tibial Fracture

Minimally invasive osteosynthesis of proximal tibial fractures has grown in popularity in recent years. This article describes a patient with a Schatzker type VI proximal tibial fracture (AO/OTA type 41.C3) and previous compartment syndrome treated with definitive fixation 8 weeks after initial injury with a precontoured proximal tibial plate and a distal targeting device. Brisk bleeding occurred during percutaneous insertion of a cortical screw at the midshaft of the tibia. Surgical exploration revealed sidewall tearing of the anterior tibial artery and vein, which were clipped at the screw insertion site. After the bleeding was controlled, the patient had a strong palpable posterior tibial pulse with no palpable dorsalis pedis pulse, and the foot remained well perfused. Function of the deep peroneal nerve was normal postoperatively. Previous concerns regarding the percutaneous treatment of proximal tibial fractures have focused on the risks of damage to the superficial peroneal nerve from distal screws. Based on cadaveric studies, percutaneously and laterally based screw placement in the distal tibial metaphysis threatens injury to the anterior tibial system. However, with alterations to the normal anatomy caused by severe trauma, previously described safe zones may be changed and neurovascular structures may be exposed to risk in locations that were previously thought safe.

Fatty Marrow and Increased Loaded Cancellous Bone was Resistant to OVX induced Bone Changes in Female Rats

ObjectivePrevious studies determined ovariectomy (OVX) induced cancellous bone loss and raised cage (RC) bipedal stance partially prevented OVX induced bone loss at red marrow bone sites in adult rats; however, these effects in the distal tibial metaphysis (DTM) with fatty marrow, a site similar to adult long bone metaphyses (non‐veterbral bone sites) with low risk of postmenopausal fracture, have yet to be determined.MethodsSix‐month‐old female S‐D rats were divided into basal, sham, OVX, RC and combination of OVX plus RC exercise for 4 and 8 weeks, cancellous bone histomorphometry on fluorescent labeled undecalcified cross sections of DTM were performed.ResultsIn DTM, OVX did not induce cancellous bone loss, but significantly increased bone turnover. RC exercise alone had no effect on cancellous bone mass, but significantly reduced bone resorption. Unlike in high turnover red marrow sites, the combination of RC exercise and OVX only partially prevented bone loss, but combining with raised cage exercise and OVX in DTM totally inhibited OVX induced cancellous bone loss by depressing bone resorption (reduced eroded perimeter).ConclusionsIn DTM, the inhibition of OVX induced bone loss can be attributing to a combination of fatty marrow content and increased mechanical loading with decreased resorption, which may partly explain why non‐vertebral bone sites are less at risk to fracture in postmenopausal patients.

Endurance exercise training enhances regional femoral and tibial bone blood flow during exercise

The principal nutrient artery to the femur demonstrates an increase in endothelium‐dependent, nitric oxide mediated vasodilation in rats after endurance exercise training. The present study sought to determine whether exercise training alters hindlimb bone blood flow distribution at rest and during exercise. Sprague‐Dawley rats were exercise trained (ET, 6–8 mo. old, n=10) with treadmill (TM) exercise at 15 m/min, 15° incline for 60 min/d over a 10–12 wk period. Sedentary (SED, n=10) control animals were acclimated to TM exercise for 5 min/d during the week preceding their blood flow measurements using the microsphere method. During exercise, ET rats demonstrated increases in blood flow to the femoral diaphysis (rest: 27 ± 8, TM: 56 ± 10 ml/min/100 g, p&lt;0.05), femoral diaphyseal marrow (rest: 92 ± 13, TM: 154 ± 29 ml/min/100 g, p&lt;0.05), distal tibial metaphysis (rest: 43 ± 13, TM: 108 ± 22 ml/min/100 g, p&lt;0.05), and tibial diaphysis (rest: 37 ± 14, TM: 68 ± 12 ml/min/100 g, p&lt;0.05). The tibial diaphyseal marrow was the only hindlimb bone region to elevate flow during exercise (rest: 92 ± 7, TM: 202 ± 21 ml/min/100 g, p&lt;0.05) in SED animals. The more generalized elevations in bone perfusion during exercise in ET rats may serve to augment medullary fluid pressures and bone interstitial fluid flow, thus benefiting bone integrity. Supported by NASA NNX09AP06G and NIH AG‐31317.

Case 1: Multifocal bone lesions in a teenager

A 15-year-old healthy female of East Indian decent presented with a two-day history of nontraumatic left ankle pain, swelling, erythema and fever, with a temperature up to 40°C. There was no other joint involvement, rashes, lethargy, weight or appetite loss, or night sweats. There was no history of recent travel, sick contacts or sexual activity. She took acetaminophen and ibuprofen for both pain and fever, but was on no other medications. Family history was negative for autoimmune conditions, inflammatory bowel disease and malignancy. Two years before she had presented with a one-week history of bilateral ankle pain followed by a four-day history of right ankle pain, swelling and erythema and a two-week history of daily fever, reduced energy and a 2.3 kg weight loss. At that time, her erythrocyte sedimentation rate (ESR) was 76 mm/h (normal 1 mm/h to 10 mm/h). Serology was negative for Epstein-Barr virus, varicella, Bartonella, Coxiella burnetii and toxoplasmosis. A malaria screen, and blood and urine cultures were negative. The joint was not aspirated at this time. Antinuclear antibody (ANA)/antineutrophil cytoplasmic antibody (ANCA) were negative and both complement component 3 and 4 were in the normal range. A bone scan (Figure 1A) showed multi-focal areas of increased activity in the right radius, right femur, and left and right tibia. She was treated with naproxen with complete resolution of her symptoms. Although there were no known tuberculosis (TB) contacts, she had a TB-positive skin test and a recent travel history to India so was treated with isoniazid for nine months for latent TB. Her ESR normalized after six months. Figure 1) Bone scans at initial presentation (A) and at admission, approximately two years later (B). X-rays of her tibia and fibula approximately one month later showed no abnormalities, other than generalized osteopenia. On current admission, she had a heart rate of 120 beats/min with a respiratory rate of 20 breaths/min and a temperature of 39.2°C. Physical examination revealed left ankle swelling and erythema, with an overall limited range of passive and active movement. Examination of her other joints was normal. The remainder of her examination was unremarkable. Twenty-four hours after presentation, despite complete resolution of her symptoms, she continued to spike fevers with temperatures >39°C. Her C-reactive protein was 20.5 mg/L (range 0 mg/L to 8 mg/L), ESR was 31 mm/h, white blood cell count was 2.9×109/L (normal 4×109/L to 10×109/L), neutrophils were 1.26×109/L (normal 2×109/L to 7.5×109/L), haemoglobin was 115 g/L (normal 120 g/L to 153 g/L) and her platelet count was were 173×109/L (normal 150×109/L to 400×109/L). Blood cultures were negative. Bone biopsy showed chronic inflammation with focal clusters of plasma cells. No malignant cells were noted. To rule out malignancy, given the low white blood cell count and boney lesions, a bone marrow aspirate was performed; it showed no increased blasts or malignant cells. Bone biopsy and bone marrow cultures were both negative for TB, bacteria and fungi. A bone scan (Figure 1B) showed intense tracer uptake in the distal left tibial metaphysis, right and left femoral meta-physis, symphysis pubis and both superior rami. X-rays of her clavicles appeared normal. She also underwent magnetic resonance imaging (MRI) of her lower extremities, which showed increased signal intensity in the left tibia and minimal joint effusion.

Micro–MR Imaging–based Computational Biomechanics Demonstrates Reduction in Cortical and Trabecular Bone Strength after Renal Transplantation

To examine the ability of three-dimensional micro-magnetic resonance (MR) imaging-based computational biomechanics to detect mechanical alterations in trabecular bone and cortical bone in the distal tibia of incident renal transplant recipients 6 months after renal transplantation and compare them with bone mineral density (BMD) outcomes. The study was approved by the institutional review board and complied with HIPAA guidelines. Written informed consent was obtained from all subjects. Micro-MR imaging of distal tibial metaphysis was performed within 2 weeks after renal transplantation (baseline) and 6 months later in 49 participants (24 female; median age, 44 years; range, 19-61 years) with a clinical 1.5-T whole-body imager using a modified three-dimensional fast large-angle spin-echo pulse sequence. Micro-finite-element models for cortical bone, trabecular bone, and whole-bone section were generated from each image by delineating the endosteal and periosteal boundaries. Mechanical parameters (stiffness and failure load) were estimated with simulated uniaxial compression tests on the micro-finite-element models. Structural parameters (trabecular bone volume fraction [BV/TV, bone volume to total volume ratio], trabecular thickness [TbTh], and cortical thickness [CtTh]) were computed from micro-MR images. Total hip and spine areal BMD were determined with dual-energy x-ray absorptiometry (DXA). Parameters obtained at the follow-up were compared with the baseline values by using parametric or nonparametric tests depending on the normality of data. All mechanical parameters were significantly lower at 6 months compared with baseline. Decreases in cortical bone, trabecular bone, and whole-bone stiffness were 3.7% (P = .03), 4.9% (P = .03), and 4.3% (P = .003), respectively. Decreases in cortical bone, trabecular bone, and whole-bone failure strength were 7.6% (P = .0003), 6.0% (P = .004), and 5.6% (P = .0004), respectively. Conventional structural measures, BV/TV, TbTh, and CtTh, did not change significantly. Spine BMD decreased by 2.9% (P < .0001), while hip BMD did not change significantly at DXA. MR imaging-based micro-finite-element analysis suggests that stiffness and failure strength of the distal tibia decrease over a 6-month interval after renal transplantation.

The Influence of Bone Type on the Gene Expression in Normal Bone and at the Bone‐Implant Interface: Experiments in Animal Model

Studies on the biological processes in different bone types and the reaction of different bone types to biomaterials are often hindered because of the difficulties in sampling procedures and lack of sensitive techniques. The purpose was to assess the suitability of quantitative polymerase chain reaction (qPCR) for investigation of the biological differences between cortical and trabecular bone types and their responses to biomaterials. Gene expression of selected markers in rat bone samples from different locations was evaluated. Samples were harvested by trephines from the trabecular femoral epiphysis, cortico-trabecular proximal tibial metaphysic, and the cortical distal tibial metaphysis. Gene expression was also evaluated at the surfaces of anodically oxidized implants retrieved from cortical and trabecular sites after 3 days of implantation. mRNA in the bone samples and in the tissue associated with the implant surfaces was extracted and quantified using qPCR. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), alkaline phosphatase (ALP), osteocalcin (OC), tartrate-resistant acid phosphatase (TRAP), cathepsin K (CATK), and 18S ribosomal subunits (18S) were analyzed. In the bone samples, higher expression of ALP, OC, TRAP, and CATK was found in femoral epiphysis compared to proximal or distal tibial metaphysis, indicating a higher turnover in the trabecular bone. On the other hand, TNF-α and IL-1β showed higher expression in both tibia sites compared with the femur site, which suggests higher inflammatory potential in the cortical bone. In response to the oxidized implants trabecular bone expressed a higher level of IL-1β, whereas the implants in cortical bone were associated with higher expression of ALP and OC. There are biological differences between cortical and trabecular bone types, both in the normal steady-state condition and in response to biomaterials. Such differences can be characterized and discriminated quantitatively using a sensitive technique such as qPCR.

Rapid growth produces transient cortical weakness: A risk factor for metaphyseal fractures during puberty

Fractures of the distal radius in children have a similar incidence to that found in postmenopausal women but occur more commonly in boys than in girls. Fractures of the distal tibia are uncommon in children and show no sex specificity. About 90% of lengthening of the radius but only 30% of lengthening of the tibia during puberty occur at the distal growth plate. We speculated that more rapid modeling at the distal radial metaphysis results in a greater dissociation between growth and mineral accrual than observed at the distal tibia. We measured the macro- and microarchitecture of the distal radial and tibial metaphysis using high-resolution peripheral quantitative computed tomography in a cross-sectional study of 69 healthy boys and 60 healthy girls aged from 5 to 18 years. Bone diameters were larger but total volumetric bone mineral density (vBMD) was lower at the distal radius (not at the distal tibia) by 20% in boys and by 15% in girls at Tanner stage III than in children of the same sex at Tanner stage I (both p < .05). In boys at Tanner stage III, total vBMD was lower because the larger radial total cross-sectional area (CSA) had a thinner cortex with lower vBMD than in boys at Tanner stage I. In girls at Tanner stage III, the larger total radial CSA was not associated with a difference in cortical thickness or cortical vBMD relative to girls in Tanner stage I. Cortical thickness and density at both sites in both sexes after Tanner stage III were greater than in younger children. Trabecular bone volume fraction (BV/TV) was higher in boys than in girls at both sites and more so after puberty because trabeculae were thicker in more mature boys but not in girls. There was no sex- or age-related differences in trabecular number at either site. We infer that longitudinal growth outpaces mineral accrual in both sexes at the distal radius, where bone grows rapidly. The dissociation produces transitory low cortical thickness and vBMD in boys but not in girls. These structural features in part may account for the site and sex specificity of metaphyseal fractures during growth.

Structural and mechanical parameters of trabecular bone estimated from in vivo high‐resolution magnetic resonance images at 3 tesla field strength

To evaluate the performance of a new 3 Tesla (T) high-resolution trabecular bone (TB) imaging technique at two resolution regimens in terms of serial reproducibility and sensitivity. The left distal tibial metaphysis of seven healthy volunteers was imaged at three time-points using a FLASE (fast large-angle spin-echo) pulse sequence at 137 x 137 x 410 mum(3) and (160 mum)(3) voxel sizes. Image artifacts, motion degradation, and serial image volume misalignments were controlled to maximize reproducibility of image-derived measures of scale, topology, orientation in terms of structural anisotropy, and finite-element derived Young's and shear moduli. Coefficients of variation (CV) and intraclass correlation coefficients (ICC) for structural and mechanical parameters were evaluated as measures of reproducibility and reliability. The ability of structural and mechanical parameters to distinguish between subjects was tested by analysis of variance. Reproducibility was generally higher in the anisotropic data (CVs 1-5% versus 1-9% for isotropic images). Anisotropic voxel size yielded greater measurement reliability (ICCs 0.75-0.99, mean = 0.92 versus 0.62-0.99, mean = 0.86) and better discrimination of the seven subjects (75% versus 50% of the possible comparisons were significantly different [P < 0.05]) except for measures of structural anisotropy and topology. Isotropic resolution improved detection of structural orientation and permitted visualization of small perforations in longitudinal trabecular plates not detected at anisotropic resolution. Improved image acquisition and processing techniques enhance reproducibility of structural and mechanical parameters derived from high-resolution MRI of metaphyseal bone in the distal tibia.

IMAGING DIAGNOSIS-MEDULLARY TIBIAL INFARCTION IN A HORSE

An Andalusian Stallion with left hind limb lameness had a radiolucent lesion in the medullary cavity of distal tibial metaphysis. After euthanasia for other disease, the tibia was examined with magnetic resonance (MR). The MR imaging sequences were characterized by a double line sign, although showing quite different lesion area intensities. Histologically, the lesion was compatible with medullary infarction being characterized by normal spongy bone, areas of abundant fibrous tissue and numerous necrotic adipocytes in various stages of destruction.

Complications Associated with Autogenous Bone Marrow Aspirate Harvest from the Lower Extremity: An Observational Cohort Study

The purpose of this article is to report the complications associated with autogenous bone marrow aspirate harvested from the lower extremity (ie, tibia and/or calcaneus) for soft tissue and/or osseous healing augmentation. This is a multisite, multisurgeon, observational cohort study involving retrospective review of prospectively collected data of 548 autogenous bone marrow aspirate harvests from the lower extremity of 530 consecutive patients between August 2000 and March 2009. Each patient underwent autogenous bone marrow aspirate harvest from the proximal medial tibial metaphysis, distal medial tibial metaphysis, medial malleolus, lateral calcaneus, medial calcaneus, or a combination of both the proximal tibial metaphysis and lateral calcaneus for application to split-thickness skin graft application sites or for mixture with allogeneic bone graft material for osseous defects or arthrodesis. Patients were kept non-weight bearing based on the index procedure and followed until clinical healing occurred or failure was declared. There were 324 female and 206 male patients with a mean age of 54.7 +/- 14.1 years (range: 14 to 84 years). There were 276 left feet/ankles and 272 right feet/ankles undergoing operative interventions with 18 harvests occurring from the proximal medial tibial metaphysis, 183 from the distal medial tibial metaphysis, 11 from the medial malleolus, 325 from the lateral calcaneus, 3 from the medial calcaneus, and 8 from both the proximal tibial metaphysis and lateral calcaneus. All procedures were deemed successful with no nerve-related injury, infection, wound-healing complications, or iatrogenic fracture occurring. When properly performed, autogenous bone marrow aspirate harvest from various locations about the lower extremity as described here represent safe and minimally invasive techniques useful for soft tissue and osseous healing augmentation. 4 (Case Series; Therapeutic Study).

The Use of Calcium Sulfate and Calcium Phosphate Composite Graft to Augment Screw Purchase in Osteoporotic Ankles

Screws placed in the distal fibula may not have satisfactory purchase during internal fixation of an osteoporotic ankle fracture. Tibia-pro-fibula screws that extend from the fibula into the distal tibial metaphysis provide additional purchase. The purpose of this study was to investigate if purchase of these screws can be enhanced further by injecting calcium sulfate and calcium phosphate composite graft into the drill holes prior to insertion of the screws. Bone density was quantified using a DEXA scan in paired cadaver legs. One leg from each pair was randomly selected for injection of composite graft into the screw holes before insertion of the screws. Two screws were inserted through the fibula into the distal tibial metaphysis in each leg, at the level of the syndesmosis under fluoroscopy in a standardized fashion in an MTS machine. After testing 4 pairs of cadaver legs, a statistically significant difference was noted in displacement (p = 0.018 distal, p = 0.0093 proximal), failure load, (p = 0.0185 distal, p = 0.0238 proximal), and failure energy (p = 0.0071 distal, p = 0.0115 proximal) between augmented and non-augmented screws, with the augmented screws being considerably stronger. Screws augmented with composite graft provide significantly greater purchase in an osteoporotic fibular fracture model. Composite graft augmented screws inserted into the distal tibia from the fibula may enhance the stability of internal fixation of an osteoporotic ankle fracture. This may enable earlier weightbearing and return to function which is important in elderly patients.

Transarticular versus Extraarticular Ankle Pin Fixation: A Biomechanical Study

Transarticular pin fixation for ankle stabilization has drawbacks, including ankle joint arthrosis. An extraarticular technique could help avoid these problems. We compared stiffness under minimal dorsiflexion loading with transarticular versus extraarticular fixation. Cadaveric specimens from ten lower extremity matched pairs were randomized to receive transarticular or extraarticular fixation. For transarticular fixation, axial pins were passed retrograde through the plantar heel, calcaneus, subtalar joint, talar body, and ankle joint. For extraarticular fixation, the first pin was inserted antegrade from the anterior distal tibia to the posterolateral aspect of the calcaneus tuberosity. The second pin was inserted percutaneously antegrade from the distal medial tibial metaphysis to the dorsal navicular, passing anterior to the ankle and dorsal to the talonavicular joint. Each specimen was subjected to 1000 cycles at 5 mm/s to 100 N. After testing, the extraarticular specimens were dissected to establish the distance of the pin from the flexor hallucis longus (FHL) tendon. There was no significant difference in stiffness between the transarticular and the extraarticular group (mean+/-standard error of the mean) (17.93 N/mm+/-1.0 N/mm and 18.61 N/mm+/-1.07 N/mm, respectively). The lateral pin was 4.2+/-1.4 mm (range, 2.5 to 6.0 mm) from the FHL. Fixation stiffness with extraarticular crossed antegrade pins was not different from that of transarticular fixation and did not disrupt the ankle or the plantar skin. Extraarticular ankle fixation may help avoid the complications found with the joint, cartilage, and plantar skin disruption associated with transarticular fixation.

Treatment of Recalcitrant Distal Tibial Nonunion Using the Descending Genicular Corticoperiosteal Free Flap

Recalcitrant nonunions of the distal tibia without bone defect are severe problems whose treatment is difficult. Stable internal fixation and osteogenetic enhancement are required. The thin corticoperiosteal flap based on the descending genicular artery has been previously described to treat nonunions in the upper extremity without bone defect. The use of this flap to treat distal tibial nonunions is reported in the present article. Twenty-five patients with recalcitrant nonunion of the distal tibial metaphysis without segmental bone defect or evidence of infection were treated with revision of the internal fixation and a corticoperiosteal free flap from the medial condyle of the femur. The number of previous surgical procedures was two to five. The flaps were compound, including muscle or fat, for wound coverage in seven cases. All compound flaps survived. Bony union was achieved in all cases, with bone formation at the nonunion site by the fourth month in all cases but one. In this case bone union took 7 months. Donor morbidity was negligible. Two tibiotalar arthrodeses were performed secondarily for posttraumatic osteoarthritis. Treatment of recalcitrant distal tibial nonunions without bone defect with removal of previous hardware, stable internal fixation, and free corticoperiosteal flap transfer is safe and effective in noninfected cases.