Analysis of Biomechanical Differences Between Condylar Constrained Knee and Rotating Hinged Implants: A Numerical Study.

BACKGROUND: Different levels of constraint for total knee arthroplasty can be considered for revision surgeries. While prior studies have assessed the clinical impact and patient outcomes of condylar constrained knee (CCK) and rotating hinged (RTH) implants, nowadays little is known about the biomechanical effects induced by different levels of constraint on bone stress and implant micromotions. METHODS: CCK and RTH implant models were analyzed using a previously validated numerical model. Each system was investigated during a squat and a lunge motor task. The force in the joint, the bone and implant stresses, and micromotions in this latter were analyzed and compared among designs. RESULTS: Different activities induced similar bone stress distributions in both implants. The RTH implant induces mostly high stress compared to the CCK implant, especially in the region close to tip of the stem. However, in the proximal tibia, the stresses achieved with the CCK implant is higher than the one calculated for the RTH design, due to the presence of the post-cam system. Accordingly, the condylar constrained design shows higher implant micromotions due to the greater torsional constraint. CONCLUSION: Different levels of constraint in revision arthroplasty were always associated with different biomechanical outputs. RTH implants are characterized by higher tibial stress especially in the region close to the stem tip; condylar implants, instead, increase the proximal tibial stress and therefore implant micromotions, as a result of the presence of the post-cam mechanism. Surgeons will have to consider these findings to guarantee the best outcome for the patient and the related change in the bone stress and implant fixation induced by different levels of constrain in a total knee arthroplasty.

Anterior Cruciate Ligament Reconstruction with LARS Artificial Ligament-Clinical Results after a Long-Term Follow-Up.

Purpose The aim of this retrospective study was to evaluate the subjective and functional outcome of anterior cruciate ligament (ACL) reconstruction with the synthetic Ligament Advanced Reinforcement System (LARS) ligament. Methods Twenty-six patients were reviewed at an average follow-up of 11.6 years. Objective clinical evaluation was performed with stability tests. Patient-reported outcomes (Visual Analogue Scale, Knee Injury and Osteoarthritis Outcome Score, and Cincinnati Knee Rating Scale) were used to assess subjective and functional outcomes. Results Overall satisfactory results were obtained in 22 cases (84.6%). Four patients (15.4%) showed mechanical failure of the graft. No cases of synovitis or infection were reported. Conclusion LARS ligament can be considered a safe and suitable option for ACL reconstruction in carefully selected cases, especially elderly patients needing a rapid postoperative recovery. Level of Evidence Level IV, retrospective case series.

Percutaneous Intramedullary Headless Screw Fixation and Wide-Awake Anesthesia to Treat Metacarpal Fractures: Early Results in 25 Patients.

Metacarpal fractures constitute 7.8% of the upper extremity fractures. The common treatments remain nonsurgical procedure, but high-demanding patients or unstable fractures require fixation with Kirschner wire (K-wires), plate, and screws. However, these approaches may cause scarring and adhesion with poor functional results. From 2014 to 2015, the authors used an intramedullary headless screw to treat 25 patients (24 men, 1 woman) with metacarpal bones fractures (20 V, 3 IV, 1 III, and 1 II). The fractures patterns were 23 fractures of distal third of metacarpal bone (16 oblique, 5 comminute configurations, and 2 transverse), 1 fracture of the base of the II metacarpal bone. One case presented a multiple metacarpal and phalangeal facture associated. The authors used wide-awake anesthesia (bupivacaine-epinephrine 1:100,000) and intramedullary titanium headless screw fixation percutaneously inserted (CCS Medartis and HCS Synthes 3 mm of diameter). No open reduction was needed. Early active mobilization started with a buddy strapping soon after surgery (0-3 days). The authors followed all patients until satisfactory function was achieved (4-6 weeks) and recorded the time till return to work. All fracture healed with less than 5 degrees of rotational or axial deformities. All patients return to work within 2.38 weeks after surgery (0.5-6 weeks). No cases of complex regional pain syndrome (CRPS), tendon lesions, nerve injuries, infection, hardware protruding, or mobilization were reported. Intramedullary screw fixation with wide-awake anesthesia for transverse, oblique, and select comminuted fractures treatment metacarpal fractures represent a reliable option to early active mobilization recovery and a quick return to the work and ordinary activities.

Carbon-fiber reinforced intramedullary nailing in musculoskeletal tumor surgery: a national multicentric experience of the Italian Orthopaedic Society (SIOT) Bone Metastasis Study Group.

INTRODUCTION: Carbon fiber reinforced (CFR) implants have been proposed for the treatment of fractures or impending fractures of the long bones in the oncology patient. Aim of this study is to present the largest cohort of oncology patients operated by CFR nailing by the Italian Orthopaedic Society (SIOT) Bone Metastasis Study Group. METHODS: 53 adult oncology patients were operated on with a CFR-PEEK nail. All the data from adjuvants therapies were collected. Bone callus formation, response to radiotherapy, relapse or progression of the osteolysis were recorded. Hardware survival and failure, breakage and need for implant revision were also analysed. RESULTS: Anatomical implantation of nails include humerus (n = 35), femur (n =11) and tibia (n = 7). The most frequent tumors affecting the bone were myeloma (n = 13), breast (n = 11), lung (n = 8), and renal cell cancer (n = 7). Acrylic cement reinforcement was used in 2 patients. One patient was subjected to electrochemotherapy after nail insertion. Intraoperative and early postoperative complications occurred in 13.2% and 7.54% of patients respectively. Eight patients had local progression and one developed a stress fracture proximally to the distal static screw. Radiographic union occurred in 14 patients; one screw loosening was recorded. DISCUSSION: There is currently a lack of solid evidence on the clinical use of CFR nails in oncologic patients. This is the first and largest study of CFR nailing, with the longest available follow up. CONCLUSIONS: Implant related complications and surgery-related morbidity should be taken into account in the decision-making process for the surgical management of these patients. These data can improve the surgeon-patient communication and guide further studies on patients' survival and complications with respect to surgery.

Profunda Femoris Artery Pseudoaneurysm after Intramedullary Fixation for a Pertrochanteric Hip Fracture.

INTRODUCTION: Vascular complications after femoral fixation are rare and not only easy to recognize but also potentially life-threatening. The aim of this case report is to describe how a pseudoaneurysm of the deep femoral artery can complicate an intramedullary nailing after a pertrochanteric fracture and how it can be treated. CASE REPORT: We report the case of a 90-year-old female who developed a pseudoaneurysm of the profunda femoris artery 16 days after intramedullary femoral nailing for a pertrochanteric hip fracture. Stenting of the artery was urgently performed with a consequent resolution of the symptoms. CONCLUSION: Diagnosis of vascular complications after hip surgery may be very challenging because symptoms are often nonspecific. Despite their rarity, it is important to know this type of complications to address the diagnostic pathway in the right direction and to treat them promptly.

Evaluation of the Effects of the Metha® Short Stem on Periprosthetic Bone Remodelling in Total Hip Arthroplasties: Results at 48 Months.

INTRODUCTION: Total hip arthroplasty is one of the most performed procedures in orthopaedic surgery. Implantation of a prosthesis determines changes in the distribution of loads on the host bone, and this phenomenon, known as stress shielding, is related to the biomechanical characteristics of the implant. Usually stress shielding involves the proximal portion of the femur by reducing the mechanical strength and ability to withstand the transmitted loads. The aim of our study is to demonstrate how the use of a short hip stem reduces the stress shielding phenomenon to the proximal femur. MATERIALS AND METHODS: The study analyzed 20 patients undergoing hip prosthesis surgery with a short stem (Metha<, B. Braun Medical, Inc., Bethlehem, Pennsylvania) at the Ist Orthopaedic Division of Pisa University (between December 2008 and January 2010). Each patient was subjected to analysis of periprosthetic bone mineral density by a bone densitometry (dual emission X-ray absorptiometry [DEXA] with the metal removal software) at 0, 6, 12, 18, 24, and 36 months, following a protocol based on the evaluation of the changes of bone density in the seven Gruen zones. RESULTS: We recorded minimal changes in bone mineral density (BMD) at the level of the greater trochanter (-1.44%) and at the level of the calcar (-3.7%). BMD increased significantly after four years at the level of the lateral distal regions (R2 +9.6% - R3 + 12.4%) and at the level of the distal medial regions (R5 + 8.2% - R6 + 13.1%). We compared the results obtained with the literature data at 12 and 24 months with the same stem (Metha<). At 12 months follow up, we did not see a significant difference between our data and the data published in the literature. However, after 48 months of follow-up, we recorded significant differences in the curves of periprosthetic bone reabsorption at the level of the greater trochanter (Zone 1) and at the level of the calcar (Zone 7). DISCUSSION: The data obtained from our study are in agreement with other studies in the literature, which demonstrates how the use of short stems preserves the metaphyseal bone stock at the level of the proximal femur, reducing the stress shielding phenomenon. From our data, obtained at 24 months and confirmed at 36, stress shielding seems to minimally occur at the level of the calcar. At the level of the great trochanter, we saw a good load distribution that maintained the baseline BMD; these data are in opposition to the literature data that showed a high increase of BMD at the level of the calcar (+12.9%) and a decrease at the level of the great trochanter. From the analysis of the radiographic images of our cases, and of the cases published with the same stem, these differences in load transfer encountered between the great trochanter and the calcar seems to be related to the level of the femoral neck osteotomy and the consequent stem position (varus/valgus). CONCLUSION: We conclude that the amount of periprostetic bone reabsorption around the Metha< stem seems to be strictly related to the surgical technique and the final implant position.

Magnetic Nanoparticles for Efficient Delivery of Growth Factors: Stimulation of Peripheral Nerve Regeneration.

The only clinically approved alternative to autografts for treating large peripheral nerve injuries is the use of synthetic nerve guidance conduits (NGCs), which provide physical guidance to the regenerating stump and limit scar tissue infiltration at the injury site. Several lines of evidence suggest that a potential future strategy is to combine NGCs with cellular or molecular therapies to deliver growth factors that sustain the regeneration process. However, growth factors are expensive and have a very short half-life; thus, the combination approach has not been successful. In the present paper, we proposed the immobilization of growth factors (GFs) on magnetic nanoparticles (MNPs) for the time- and space-controlled release of GFs inside the NGC. We tested the particles in a rat model of a peripheral nerve lesion. Our results revealed that the injection of a cocktail of MNPs functionalized with nerve growth factor (NGF) and with vascular endothelial growth factor (VEGF) strongly accelerate the regeneration process and the recovery of motor function compared to that obtained using the free factors. Additionally, we found that injecting MNPs in the NGC is safe and does not impair the regeneration process, and the MNPs remain in the conduit for weeks.

How to Direct the Neuronal Growth Process in Peripheral Nerve Regeneration: Future Strategies for Nanosurfaces Scaffold and Magnetic Nanoparticles.

Currently, the gold standard to repair large nerve defects is the autologous nerve graft. These solutions offer a mechanical support, adhesion substrates, and, with Schwann cells (SC), a source of neurotropic factors for axonal growth. The technical limits are the donor side damage, multiple surgical accesses, and the unavailability of large amounts of grafts. In recent years, several researchers focused their attention on the interaction between cells (nervous and glial) and physic-chemical cues that arise from the extracellular milieu. Nanotechnologies produce surfaces that mimic the topographical signals (physical stimuli) that arise from enterprise content management (ECM) to modulate the forces acting during axonal elongation. The use of magnetic nanoparticles (MNPs) seems to be able to guide and to boost the nerve regeneration. Both research areas could be improved through surfaces functionalization by biological molecules (proteins/peptides, growth factors, etc.). In the future, the aim will be to help recovery after peripheral nerve lesion by producing a tridimensional structured conduit, then repeat the ECM architecture and take advantage of MNPs internalized by cells and guide them through tension forces by external magnetic fields to stimulate and direct axon growing. The aims of this review were to evaluate the findings of studies that used physical stimuli (nanoscaffold surfaces and MNPs) used for peripheral nerve regeneration support. The future trends in the field of peripheral nerve regeneration continue to produce a wide variety of new techniques to improve the opportunity for advances to treat peripheral nerve injuries.

Nanoparticles for Tendon Healing and Regeneration: Literature Review.

Tendon injuries are commonly met in the emergency department. Unfortunately, tendon tissue has limited regeneration potential and usually the consequent formation of scar tissue causes inferior mechanical properties. Nanoparticles could be used in different way to improve tendon healing and regeneration, ranging from scaffolds manufacturing (increasing the strength and endurance or anti-adhesions, anti-microbial, and anti-inflammatory properties) to gene therapy. This paper aims to summarize the most relevant studies showing the potential application of nanoparticles for tendon tissue regeneration.

The difference in activity of daily living (ADL) and mortality in patients aged over 80 years with femoral neck fracture treated with hemiarthroplasty or osteosynthesis at 2 years of follow-up.

INTRODUCTION: Hip fractures are one of the major causes of morbidity and mortality in the elderly and outcomes following hip fracture have been the focus of several studies over recent decades. Among all types of fall-related injuries, hip fractures cause the greatest number of deaths, lead to severe health problems and reduce quality of life. Improving the outcome of hip fracture surgery has thus become one of the main areas of interest for orthopaedic surgeons. The aim of this study was to compare the difference in activity of daily living (ADL) and mortality between patients aged over 80 years with hip fracture treated with osteosynthesis versus prosthesis at 2 years of follow-up. MATERIALS AND METHODS: The data were collected on admission and during in-hospital stay. Information recorded on admission included: age, sex, type and mechanism of fracture, functional and cognitive status, comorbidity, and severity of illness. Prefracture functional status was measured. The follow-up was clinical and radiographical, or was by telephone for patients who were not able to come to the clinic. Patients aged over 80 years who underwent a single surgical procedure treated with intramedullary nail or hemiarthroplasty were included in the study. RESULTS: A total of 174 patients (45 male and 129 female) were included in the study. The two treatment groups were comparable for all preoperative parameters except for preoperative haemoglobin, which was an average of 1g/dl higher in the patients given hemiarthroplasty compared with those treated with intramedullary nail (t-test: p<0.05). The average observation period was 594.99days; the number of deaths was 62 of 164 contacted patients, and the survival rate at 2 years was 62.2%. There was increased mortality in patients who underwent hemiarthroplasty (Log-rank Mantel-Cox, p: 0,048). The difference in ADL between preoperative and follow-up is not statistically significant between the two groups. DISCUSSION: In the literature, there are few specific studies that consider these parameters in this population. However, these findings are consistent with the findings from other studies. CONCLUSION: Patients who received hemiarthroplasty have a higher mortality risk than those treated with intramedullary nail; there are no differences in ADL at follow-up.

Human mesenchymal stromal cell-enhanced osteogenic differentiation by contact interaction with polyethylene terephthalate nanogratings.

Among the very large number of polymeric materials that have been proposed in the field of orthopedics, polyethylene terephthalate (PET) is one of the most attractive thanks to its flexibility, thermal resistance, mechanical strength and durability. Several studies have been proposed that interface nano- or micro-structured surfaces with mesenchymal stromal cells (MSCs), demonstrating the potential of this technology for promoting osteogenesis. All these studies were carried out on biomaterials other than PET, which remains almost uninvestigated in terms of cell shaping, alignment and differentiation. Here, we study the effect of PET 350-depth nanogratings (NGs) with a ridge and lateral groove size of 500 nm (T1) or 1 µm (T2), on bone marrow-derived human MSC (hMSC) differentiation in relation to the osteogenic fate. We demonstrate that these substrates, especially T2, can promote the osteogenic phenotype more efficiently than standard flat surfaces and that this effect is more marked if cells are cultured in osteogenic medium than in basal medium. Finally, we show that the shape and disposition of calcium hydroxyapatite granules on the different substrates was influenced by the substrate symmetry, being more elongated and spatially organized on NGs than on flat surfaces.

Hydroxyapatite in total hip arthroplasty. Our experience with a plasma spray porous titanium alloy/hydroxyapatite double-coated cementless stem.

PURPOSE: Total hip arthroplasty could fail due to many factors and one of the most common is the aseptic loosening. In order to achieve an effective osseointegration and reduce risk of lossening, the use of cemented implant, contact porous bearing surface and organic coating were developed. Aim of this study was to evaluate clinical and radiological mid-term outcomes of a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem applied with "plasma spray" technique and to demonstrate the possibility to use this stem in different types of femoral canals. METHODS: Between January 2008 and December 2012, 240 consecutive primary total hip arthroplasties (THAs) were performed using a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem. 182 patients were examined: 136 were females (74.7%) and 46 males (25.2%); average age was 72 years old (ranging from 26 to 92 years old). For each patient, Harris Hip Scores (HHS) and Womac Scores were collected. All X-ray images were analyzed in order to demonstrate stem survival rate and subsidence. RESULTS: Harris Hip Score was good or excellent in 85% of the cases (average 90%) and mean WOMAC score was 97.5 (ranging from 73.4 to 100). No cases of early/late infection or periprosthetic fracture were noticed, with an excellent implant survival rate (100%) in a mean period of 40 months (ranging from 24 and 84 months). 5 cases presented acute implant dislocation, 2 due to wrong cup positioning in a dysplastic acetabulum and 3 after ground level fall. Dorr classification of femoral geometry was uses and the results were: 51 type A bone, 53 type B bone and 78 type C bone. Stem subsidence over 2 mm was considered as a risk factor of future implant loosening and was evidenced in 3 female patients with type C of Dorr classification. No radiolucencies signs around the proximally coated portion of stem or proximal reabsorption were visible during the radiographic follow-up. CONCLUSIONS: Concerning the use of porous titanium alloy/hydroxyapatite double coating, this study reported an excellent implant survival rate in a mid-term period with a rate of 1,64% of subsidence in patients with type C of femoral canal but with an optimal HHS and Womac Score results. Regarding this stem, primary stability is guaranteed by trapezoid shape of proximal region and tapering in frontal plane through press-fit technique. Radiological absence of pedestal has been accepted as sign of no excessive stress transmission to distal cortex due to its tapered diaphyseal region. Thanks to the reported data, Authors can consider this double coating a valid choice with an excellent medium-term survival and encouraging subsidence results. Further studies are needed to ensure these results can be replicated.

Prospective Randomized Controlled Trial of Two Different Intramedullary Nails for Pertrochanteric Fractures of the Femur.

The purpose of this prospective randomized trial was to assess whether an intramedullary nail is superior or not to another one in the treatment of pertrochanteric fractures. Eighty-one patients with a 31-A1 or A2 Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) pertrochanteric fracture were randomly allocated to fixation with either the Gamma® or the ENDOVIS® nail. In order to estimate the functional outcome the Parker-Palmer mobility score, Barthel Index, and EuroQol-5D (EQ-5D) were used. All patients were followed up at 1, 3, 6, and 12 months postoperatively. There was no statistical difference in Parker mobility score between groups. The statistical analysis revealed that there was no significant difference between the two patient groups as far as the operating time, the amount of blood transfused, and the latest functional outcome. Both kinds of intramedullary nails used in our study provide effective methods of treatment for intertrochanteric fractures in elderly patients. Our data showed slightly worse results for the ENDOVIS nail compared with the Gamma nail, but this did not reach a statistical significance.

Postoperative Spine Infections.

Postoperative spinal wound infection is a potentially devastating complication after operative spinal procedures. Despite the utilization of perioperative prophylactic antibiotics in recent years and improvements in surgical technique and postoperative care, wound infection continues to compromise patients' outcome after spinal surgery. In the modern era of pending health care reform with increasing financial constraints, the financial burden of post-operative spinal infections also deserves consideration. The aim of our work is to give to the reader an updated review of the latest achievements in prevention, risk factors, diagnosis, microbiology and treatment of postoperative spinal wound infections. A review of the scientific literature was carried out using electronic medical databases Pubmed, Google Scholar, Web of Science and Scopus for the years 1973-2012 to obtain access to all publications involving the incidence, risk factors, prevention, diagnosis, treatment of postoperative spinal wound infections. We initially identified 119 studies; of these 60 were selected. Despite all the measures intended to reduce the incidence of surgical site infections in spine surgery, these remain a common and potentially dangerous complication.

Treatment of Scaphoid Waist Nonunion Using Olecranon Bone Graft and Stryker Asnis Micro Cannulated Screw: A Retrospective Study-80 Case Studies and 6 Years of Follow-Up.

Background Screw fixation and bone grafting are the gold standard for scaphoid waist nonunion without avascular necrosis. Question/Purpose Assesses the scaphoid waist nonunion healing rate with use of an uncommon cancellous bone graft (olecranon) and an unusual fixation system (Asnis Micro Cannulated Screw System; Stryker Inc., Kalamazoo, MI, USA). Material and Methods A series of 102 consecutive patients were treated for scaphoid waist nonunion (without deformity). Of these, 80 patients subjected to clinical (Modified Mayo Wrist Score (MMWS), Jamar hydraulic dynamometer) and radiographic examination before and after surgery were evaluated. Ipsilateral olecranon cancellous bone graft and the ASNIS Micro 3.0-mm diameter screw, were used. The average follow up was 6 years (min 3; max 10). Results Radiographic consolidation was achieved in 90% of patients; dorsal intercalated segment instability (DISI) deformities were corrected in 71.4% of cases. Ninety percent improved the range of motion of the wrist and grip strength. All patients showed a significant reduction of peak force in the operated hand. In 6.25% we observed clinical and radiographic screw head-trapezium impingement. Twenty-six patients developed a degenerative wrist sign. The MMWS yielded 68 optimal, 8 good, and 4 bad results. Conclusions To treat scaphoid waist nonunions without misalignment, low-profile headed screw and olecranon bone graft allowed a high consolidation rate with positive results to long-term follow-up. The Asnis Micro 3.0 mm diameter screw may be a suitable option for treating scaphoid waist nonunion. Level of Evidence IV.

Atraumatic Bilateral Neglected Anterior Shoulder Dislocation: Case Report of a Jehovah's Witness 28-Year-Old Male Affected by Iron-Deficiency Anemia and Treated with Bilateral Latarjet Procedure.

INTRODUCTION: Neglected bilateral anterior shoulder dislocation is a very rare condition, often related to seizures or major trauma. Open reduction is recommended whenever Hill-Sachs lesion is >25% of the joint and the dislocation is elder than 3 weeks. CASE REPORT: We describe a case report of a 28-year-old man left handed Jehovah's Witness laborer assessed 12 weeks after bilateral anterior shoulder dislocation. The patient was evaluated with clinical examination, and it was observed an asymptomatic intrarotation of both shoulders with a mild left circumflex nerve deficit. He was able to perform flexion and abduction of both arms up to 60° and 10° of extrarotation. Pre-operative constant scores were 49 in left and 55 in right shoulder, pre-operative disabilities of the arm, shoulder, and hand (DASH) scores were 57 in left and 53 in right shoulder, and visual analogue scales (VAS) was 2. Radiological examination were bilateral anteroposterior shoulder X-rays and computer tomography scan. The surgeon treated both shoulder (not simultaneously) by open reduction and Bristow-Latarjet coracoids transfer procedure. A 1 year after operations, left flexion was 180° while right was 160, bilateral abduction was 180. He was able to return to his pre-injury activities, the constant score was 89 left and 83 right, DASH score was 17 left and 13 right and VAS was 0. CONCLUSION: Atraumatic bilateral neglected anterior shoulder dislocation can be treated with open Bristow-Latarjet procedure to provide a stable glenohumeral joint in laborer patient and permit a return to the pre-injury activities, to create a greater extension of the glenoid arc and to avoid future dislocation.

Case report: late subtrochanteric fracture post radiofrequency ablation of osteoid osteoma.

Osteoid osteoma is a benign tumor especially affecting young males generally treated with radiofrequency ablation. This is a non-invasive and safe procedure, major complications are very rare, most of them consisting in local skin burns. The present case shows a late subtrochanteric fracture in a young boy after CT guided termoablation of osteoid osteoma of proximal femur and short review of the literature.

Biomechanics of interspinous devices.

A number of interspinous devices (ISD) have been introduced in the lumbar spine implant market. Unfortunately, the use of these devices often is not associated with real comprehension of their biomechanical role. The aim of this paper is to review the biomechanical studies about interspinous devices available in the literature to allow the reader a better comprehension of the effects of these devices on the treated segment and on the adjacent segments of the spine. For this reason, our analysis will be limited to the interspinous devices that have biomechanical studies published in the literature.

Effect of vitamin D in fracture healing in a child: case report.

UNLABELLED: In this report, we describe the effect of vitamin D and calcium supplementation on fracture healing in a young boy with a hypovitaminosis D who had a radius refracture. The radiographic evaluation of the callus formation shows a clear effect of vitamin D on fracture healing in absence of additional variables. INTRODUCTION: Fracture healing restores the tissue to its original physical and mechanical properties and it involves a complex multistep process that involves response to injury, intramembranous bone formation, chondrogenesis, endochondral bone formation, and bone remodeling. All this process is influenced by a variety of systemic and local factors. It is generally assumed that vitamin D plays an intimate role in healing fractures; however, very little data exists on how it does. CASE REPORT: In this report, the authors describe the effect of vitamin D and calcium supplementation on fracture healing in a young boy with a hypovitaminosis D who had a radius refracture. CONCLUSIONS: Our case report suggests that the hypovitaminosis D is a possible cause of inadequate fracture healing and refracture in children and it shows a clear effect of vitamin D supplementation on callus formation in the absence of additional variables.