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The aim of this study was to compare the results of treatment of segmental tibial defects in the pediatric age group using an Ilizarov external fixator versus a nonvascularized fibular bone graft. This study included 24 patients (age range from 5.5 to 15 years) with tibial bone defects: 13 patients were treated with bone transport (BT) and 11 patients were treated with a nonvascularized fibular graft (FG). The outcome parameters were bone results (union, deformity, infection, leg-length discrepancy) and functional results: external fixation index and external fixation time. In group A (BT), one patient developed refracture at the regenerate site, whereas, in group B (FG), after removal of the external fixator, one of the FGs developed a stress fracture. The external fixator time in group A was 10.7 months (range 8-14.5) versus 7.8 months (range 4-11.5 months) in group B (FG). In group A (BT), one patient had a limb-length discrepancy (LLD), whereas, in group B (FG), three patients had LLD. The functional and bone results of the Ilizarov BT technique were excellent in 23.1 and 30.8%, good in 38.5 and 46.2, fair in 30.8 and 15.4, and poor in 7.6 and 7.6%, respectively. The poor functional result was related to the poor bone result because of prolonged external fixator time resulting in significant pain, limited ankle motion, whereas the functional and bone results of fibular grafting were excellent in 9.1 and 18.2%, good in 63.6 and 45.5%, fair in 18.2 and 27.2%, and poor in 9.1 and 9.1%, respectively. Segmental tibial defects can be effectively treated with both methods. The FG method provides satisfactory results, with early removal of the external fixator. However, it had a limitation in patients with severe infection and those with LLD. Also, it requires a long duration of limb bracing until adequate hypertrophy of the graft. The Ilizarov method has the advantages of early weight bearing, treatment of postinfection bone defect in a one-stage surgery, and the possibility to treat the associated LLD. However, it has a long external fixation time.

Porous metaphyseal cones are widely used in revision knee arthroplasty. A new system of porous titanium metaphyseal cones has been designed based on the femoral and tibial morphology derived from a computed tomography-based anatomical database. The purpose of this study is to evaluate the initial mechanical stability of the new porous titanium revision cone system by measuring the micromotion under physiologic loading compared with a widely-used existing porous tantalum metaphyseal cone system.The new cones were designed to precisely fit the femoral and tibial anatomy, and 3D printing technology was used to manufacture these porous titanium cones. The stability of the new titanium cones and the widely-used tantalum cones were compared under physiologic loading conditions in bench top test model.The stability of the new titanium cones was either equivalent or better than the tantalum cones. The new titanium femoral cone construct had significantly less micromotion compared with the traditional femoral cone construct in 5 of the 12 directions measured (P.05), whereas no statistical difference was found in 7 directions. The new porous titanium metaphyseal tibial cones demonstrated less micromotion in medial varus/valgus (P = .004) and posterior compressive micromotion (P = .002) compared with the traditional porous tantalum system.The findings of this biomechanical study demonstrate satisfactory mechanical stability of an anatomical-based porous titanium metaphyseal cone system for femoral and tibial bone loss as measured by micromotion under physiologic loading. The new cone design, in combination with instrumentation that facilitates surgical efficiency, is encouraging. Long-term clinical follow-up is warranted.

Remnants of ACL have been reported to promote recovery of proprioceptive functions in a graft, resulting in the technique of ACL augmentation becoming accepted widely. We recommend that ACL augmentation is performed in the following cases: ACL remnant retained as a thick ACL remnant bridged between the intercondylar notch and tibia, partial rupture of the PL bundle, and partial rupture of the AM bundle. This procedure is usually performed using the three-portal technique, involving the anterolateral, central anteromedial, and far anteromedial (FAM) portals. The ACL femoral attachment is accessed anatomically through the FAM portal. To make the tibial bone tunnels, guide wires are inserted at the tibial attachment of the ACL remnant and then are over-drilled, making sure that the drill tip does not reach the ACL remnant fibers to minimize damage. Then, a passage is created through the slit made in the ACL remnants. After passing the graft tendon through the slit and checking the length change of the graft during knee flexion, the graft is fixed to the tibia using two staples. Currently, patients undergoing ACL augmentation go through the same postoperative rehabilitation as those undergoing ACL reconstruction.

Morphological closing is a powerful tool for recovering and smoothing altered structures. Classic morphological closing uses constant and predefined structuring element that is well-adapted to regular shapes. However, the use of such structuring elements may deteriorate the information held by more complex and heterogeneous objects. In this paper, we present a new method for adaptive morphological closing where inertia tensors are used to estimate the geometrical characteristics of local structures and then on high resolution X-ray images of tibial bone microstructure.

This study aimed to evaluate changes in tibial bone speed of sound (SOS) over time, in preterm and term infants during infancy, in addition to identifying factors influencing the development of tibial SOS during infancy. Preterm (n = 155) and term (n = 65) infants were enrolled in this study. Tibial bone SOS was measured using quantitative ultrasonography (QUS) on the left tibia of newborn infants after birth (within 7 days), at 1 month old, and then every 2 months until subjects were approximately 12-15 months old. Follow-up checks included anthropometric measurements and tibial bone SOS. Mean tibial bone SOS at birth was significantly higher in term infants (mean ± SD, 2968.5 ± 99.7 m/s) than in preterm infants (2912.2 ± 122.6 m/s). Values of follow-up tibial bone SOS declined for the first 4 months, and then increased gradually until 12-15 months old. This increasing trend was greater in preterm infants after 2 months of corrected age than in term infants. There were no significant differences by 12-15 months of age between preterm and term infants. A longitudinal mixed-effect model controlling for internal correlations and other covariates in the two groups showed that age and the SOS value at birth were important factors affecting the tibial bone SOS in both preterm and term newborn infants during infancy. There are significant differences in the pattern of change in tibial bone SOS values between preterm and term infants during the first 12-15 months of life. Age and SOS value at birth were important factors affecting the pattern of tibial bone SOS change in both preterm and term newborn infants during infancy.

Femoral and tibial bone tunnel enlargement has been reported after anterior cruciate ligament (ACL) reconstruction. Although the exact etiology of bone tunnel enlargement after ACL reconstruction remains unknown, a complex interplay between mechanical and biological factors has been proposed to explain this phenomenon. The mechanical factors include motion of the graft within the bone tunnel, fixation methods or devices, stress shielding of the graft, improper graft placement, and rehabilitation protocols. The biological factors include the infiltration of inflammatory cytokines or synovial fluid into the bone tunnel, the use of allograft tissue, and the bioabsorbable fixation device. These factors are thought to induce osteolysis and bone tunnel enlargement after ACL reconstruction. Several studies reported that bone tunnel enlargement did not affect the clinical results; however, enlarged bone tunnel often complicates revision ACL reconstruction. This chapter describes the multiple causes of bone tunnel enlargement after ACL reconstruction. Future research and improvement of surgical technique are aimed at prevention of bone tunnel enlargement.

PURPOSE: To understand the relationship between tibial bone defect and extent of medial release in total knee arthroplasty. MATERIALS AND METHODS: We evaluated 32 knees in 22 patients with variable degrees of tibial bone defect on medial plateau has undergone total knee arthroplasty. In this study, 31 cases had been diagnosed as degenerative osteoarthritis and 1 case was osteonecrosis. We excluded cases with infection, traumatic arthritis, or neuropathic joints. With regard to gender, 29 cases were female and 3 cases were male. The following relationships were analyzed: preoperative degrees of tibial bone defect and varus deformity; the femorotibial angle of both weight-bearing whole extremity radiogram, distractive stress radiogram, and the extent of medial release. RESULTS: Average tibial bone defect was 9.8±4.1 mm. Average femorotibial angle on weight-bearing whole extremity radiograph was varus 10.0°±6.2°. Average femorotibial angle on distractive stress radiograph was varus 0.7°±4.6°. Statistically the extent of medial release showed no significant relationship with the degree of tibial bone defect and femoro-tibial angle of whole extremity radiogram. However, it revealed a statistically significant relationship with the femorotibial angle on distractive radiogram (r=0.465, p=0.007). CONCLUSIONS: Preoperative distractive stress radiograph might be a useful method to predict the extent of intraoperative medial release during total knee arthroplasty.

Background Mechanical loosening is the most common cause of revision in unicompartmental knee arthroplasty. We determined the effect of bone lavage on tibial cement penetration and interface temperature with controlled ligament tension forces. We presumed pulsed lavage would allow increased cement penetration compared with syringe lavage. Methods Cemented unicompartmental knee arthroplasty was performed in 12 pairs of fresh–frozen knees. Lavage was performed using pulsed lavage on one side (A) and syringe lavage on the other (B). Cement penetration pressure, interface temperature, and ligament tension forces were continuously monitored during the operation. Screened radiographs were taken and cement penetration under the tibial plateau was measured. Findings The pulsed lavage group showed a mean cement penetration area of 187.24 (SD 36.37) mm², whereas 144.29 (SD 35.74) mm 2 was measured in the group with syringe lavage. Cement penetration pressure was 13.29 (SD 8.69) kPa in Group A and 20.21 (SD 7.78) kPa in Group B. Maximum interface temperatures of 46.99 °C were observed in Group A and 45.02 °C in Group B. Interpretation Our data showed pulsed lavage cleansing of the cancellous tibial bone substantially improved cement penetration compared with syringe lavage without reaching the temperature threshold for bone necrosis. We recommend the routine use of pulsed lavage to improve long-term fixation.

This study examined the correlation between osteoporosis and the degeneration of intervertebral discs. Sprague-Dawley rats were maintained up to 22 or 28 months. The femoral bone, tibial bone and lumbar vertebra were histologically studied and the expression of collagen type II and X in intervertebral discs was immunohistochemiscally determined. Several indices for the degeneration of intervertebral discs and osteoporosis and the correlation among them were then analyzed. Close correlations were found among the indices for the degeneration of intervertebral discs, including the relative area of the vascular bud, the ratio of the uncalcified and the calcified layers, the expression of collagen type II and X. The correlation with collagen type X was negative. There existed positive correlations among the indices for osteoporosis, including the thickness ratio of cortical bone, the relative area of bone trabecula, the density of femoral and vertebral body bones, and the maximum stress and strain on bone. Analysis on the relationship of osteoporosis and the disease on disc showed that the indices of osteoporosis were negatively correlated with the indices of the degeneration of intervertebral discs but the expression of collagen type X was positively correlated, with the density of vertebral body bones having the strongest dependence on collagen type X. The maximum stress and strain bore no correlation with the degeneration of intervertebral discs. These results suggest that osteoporosis was negatively correlated with the degeneration of intervertebral discs.

Objective: Many treatment methods are available for the reconstruction of bone de - fects of the mandible with a number of advantages and disadvantages. Current studies in mandible reconstructions are focused on stem cells. In this study, we aimed to investigate the effect of mes - enchymal stem cell (MSC) procedure on new bone formation in directed bone enhancement. Ma- terial and Methods: The study was carried out with 7 New Zealand rabbits. Mesenchymal stem cells isolated from the tibial bone of a rabbit not included in the study, were transferred after in vitro proliferation to the calvariums of rabbits included in the experiment using a collagen carrier. Tita - nium capsules were used in order to prevent dispersion of MSCs in the tissue and to isolate them from tissues other than bones. The study was planned to include four test groups and each rab - bit was implanted four titanium capsules. While Groups A and B underwent decortication, MSC were transplanted to Groups A and C. Neither decortication nor MSC was used in Group D. The amount of new bone formation was evaluated with six score grades and histopathologically. Re- sults: A statistically significant difference was found between groups in terms of bo ne formation and the amount of new bone formation was significantly higher in Group A compared to Group D. Conclusion: MSCs successfully induce new bone formation and directed tissue regeneration cages that are produced according to the defect enable deriving new bone tissue with the required vol - ume and shape.

The utilization of stem cell therapies is a trending topic in plastic surgery and fat tissue is the most commonly used stem cell source. Stem cell injection has become popular in the treatment of burn wound, especially in the late term scar modulation. However, insufficient amounts of fat tissue in the pediatric age group is a major limitation. The present study reports the utilization of tibial bone marrow aspiration as a source of mesenchymal stem cells in the pediatric age group with the simultaneous usage of x-ray examination to avoid epiphyseal damage. [Arch Clin Exp Surg 2017; 6(1.000): 56-57]

Bone defects are occasionally encountered during primary total knee replacement (TKR) and cause difficulty in establishing a stable well-aligned bone-implant interface. Between March 1999 and November 2005, 59 knees in 43 patients underwent primary TKR with a metal block augmentation for tibial bone deficiency. In all, six patients (eight knees) died less than four years post-operatively, and four patients (five knees) were lost to follow-up leaving 46 knees in 33 patients available for review at a mean of 78.6 months (62 to 129). The clinical results obtained, including range of movement, American Knee Society and Oxford knee scores, and the Western Ontario and McMaster Universities osteoarthritis index, were good to excellent, with no failures. Radiolucent lines at the block-cement-bone interface were noted in five knees (11%) during the first post-operative year, but these did not progress.Modular rectangular metal augmentation for tibial bone deficiency is a useful option. No deterioration of the block-prosthesis or block-cement-bone interface was seen at minimum of five years follow-up.

Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years) of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm). The mean length of the graft was 16.7 cm (range 11.5 - 21 cm). The osteoseptocutaneous flap (bone flap with attached overlying skin flap) from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months). The Pearson correlation coefficient (r) was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft union occurred in all patients in a mean time of 3.3 months, at both ends. At a minimum followup of 24 months the mean hypertrophy noted was 63.6% (30 - 136%) in the vascularized fibular graft. Ten stress fractures occurred in seven patients. The mean duration of the occurrence of a stress fracture in the graft was 11.1 months (2.5 - 18 months) postoperatively. The highest incidence of stress fractures was when the graft hypertrophy was less than 20%. The incidence of stress fractures reduced significantly after the graft hypertrophy exceeded 20%. Conclusion : In most cases hypertrophy of the vascularized fibular graft occurs in response to mechanical loading by protected weight bearing, and the amount of hypertrophy is variable. The presence or absence of an intact fibula has no bearing on the hypertrophy or incidence of stress fracture. The length of the fibular graft has no bearing on the hypertrophy or stress fracture.

To assess the presence of tibial bone tunnel enlargement after surgery to reconstruct the anterior cruciate ligament using quadruple flexor tendon grafts, and to propose a new technique for its measurement. Methods: The study involved 25 patients aged 18-43 years over a six-month period. The assessment was based on radiographs taken immediately postoperatively and in the third and sixth months of evolution after operations to reconstruct the anterior cruciate ligament using grafts from the tendons of the semitendinosus and gracilis muscles, fixed in the femur with a transverse metal screw and in the tibia with an interference screw. The radiographs were evaluated in terms of the relative value between the diameter of the tunnel and the bone, both at 2 cm below the medial tibial condyle. Results: There were significant increases in tunnel diameters: 20.56% for radiographs in anteroposterior view and 26.48% in lateral view. Enlargement was present in 48% of anteroposterior and lateral radiographs, but was present in both views in only 16% of the cases. Conclusions: Bone tunnel enlargement is a phenomenon found in the first months after surgery to reconstruct the anterior cruciate ligament. The measurement technique proposed in this study was sufficient to detect it.

This study was examined the effects of deepsea water (DSW) supplementation and swimming exercise on bone metabolism in growing male rats. Thirty-two Sprague-Dawley male rats, 6 weeks of age, were randomly divided into high-fat diet sedentary (HS, n=8) or exercised group (HE, n=8) and DSW supplemented sedentary (DS, n=8) or exercised group (DE, n=8), given a high fat diet to all groups for 8 weeks. In the results, serum osteocalcin level of the DS was significantly lower than that of the HS (p

OBJETIVO: Avaliar e comparar o posicionamento dos túneis ósseos na cirurgia de reconstrução do ligamento cruzado anterior (LCA) pela técnica artroscópica e pela técnica aberta através da artrotomia. MÉTODO: Foi realizado um estudo retrospectivo comparativo de 70 pacientes acometidos por lesão do LCA. Trinta e cinco pacientes foram submetidos à reconstrução do LCA por via aberta e 35 por via artroscópica utilizando a técnica via portal anteromedial. Todos os pacientes foram submetidos à reconstrução do LCA usando enxerto autólogo do terço central do tendão patelar fixado com parafusos de interferência. As radiografias pós-operatórias foram revisadas e o posicionamento do túnel femoral foi avaliado pelos métodos propostos por Harner e Aglietti, enquanto o túnel tibial foi avaliado pelo método proposto por Staubli e Rauschning. RESULTADOS: Foram observados 54 pacientes do sexo masculino e 16 do sexo feminino. A média de idade na ocasião do procedimento foi de 34 anos e três meses, variando de 17 a 58 anos. A técnica artroscópica mostrou-se mais precisa que a técnica aberta quanto ao posicionamento dos túneis ósseos, tanto femoral quanto tibial. CONCLUSÃO: Através da análise radiológica dos joelhos submetidos à reconstrução do LCA, observou-se que o posicionamento dos túneis ósseos, tanto femoral quanto tibial, apresenta menor variação quando a cirurgia é feita pela via artroscópica. OBJECTIVES: To evaluate and compare bone tunnel positioning in anterior cruciate ligament (ACL) reconstruction surgery using the arthroscopic technique and the open technique consisting of arthrotomy. METHOD: A comparative retrospective study on 70 patients with ACL lesions was conducted. Thirty-five patients underwent ACL reconstruction by means of the open technique and 35 by means of the arthroscopic technique using an anteromedial portal. All the patients underwent ACL reconstruction using an autologous graft from the middle third of the patellar tendon, fixed using interference screws. The postoperative radiographs were reviewed and the positioning of the femoral tunnel was evaluated using the methods proposed by Harner and Aglietti, while the tibial tunnel was assessed using the method proposed by Rauschning and Staubli. RESULTS: Fifty-four of the patients were male and 16 were female. Their mean age at the time of the procedure was 34 years and 3 months, with a range from 17 to 58 years. The arthroscopic technique was shown to be more accurate than the open technique for positioning both the femoral and the tibial bone tunnels. CONCLUSIONS: Radiological analysis on the knees subjected to ACL reconstruction showed that the positioning of both the femoral and the tibial bone tunnels presented less variation when the surgery was performed arthroscopically.

Aseptic loosening of the tibial component remains a major cause of failure in total knee arthroplasty and may be related, directly or indirectly, to micromotion. Therefore, good fixation of the tibial component is a prerequisite to achieve long-term success of the implant. Cementing technique is one of the factors that play a role in this respect. We investigated the effect of different cementing techniques on the cement penetration in the proximal tibia. We compared 5 different cementing techniques in an anatomical open pore sawbone model (n = 25), using a contemporary total knee arthroplasty design and standard polymethylmetacrylate cement. We demonstrated that applying cement to both the undersurface of the tibial baseplate and as well as onto the tibial bone, either by a spatula or fingerpacking technique, leads to an optimal cement penetration of 3 to 5 mm. When cement is applied only onto the tibial component, penetration is insufficient. When a cement gun is used, cement penetration is too excessive.

The aim of this study was to investigate whether the bone response to long bed rest-related immobility and during subsequent recovery differed at anatomically different sectors of tibial epiphysis and diaphysis. For this study, peripheral quantitative tomographic (pQCT) scans obtained from a previous 90-day 'Long Term Bed Rest' intervention were preprocessed with a new method based on statistical approach and re-analysed sector-wise. The pQCT was performed on 25 young healthy males twice before the bed rest, after the bed rest and after 1-year follow-up. All men underwent a strict bed rest intervention, and in addition, seven of them received pamidronate treatment and nine did flywheel exercises as countermeasures against disuse-related bone loss. Clearly, 3-9% sector-specific losses in trabecular density were observed at the tibial epiphysis on average. Similarly, cortical density decreased in a sector-specific way being the largest at the anterior sector of tibial diaphysis. During recovery, the bed rest-induced bone losses were practically restored and no consistent sector-specific modulation was observed in any subgroup. It is concluded that the sector-specific analysis of bone cross-sections has potential to reveal skeletal responses to various interventions that cannot be inferred from the average analysis of the whole bone cross-section. This approach is considered also useful for evaluating the bone responses from the biomechanical point of view.

Patient anatomy specific orthopaedic implant design, fabrication and identification of the most suitable position to fix implants onto bone fractures are challenging problems for surgeons to overcome of the existing shortcomings of commercially available implants. In this work, a 3D finite element model of the left tibial bone of an adult male is developed from Computed Tomography scan images. Proximal tibial fracture type B1 (as per Association for the Study of Internal Fixation) is simulated on the bone model. A geometry specific implant is obtained in order to promote better bone ingrowths and uniform stress distribution, by extracting the surface features of the bone. Finite Element Analysis is performed to evaluate and compare the mechanical properties such as stress, strain and displacement of the bone and implant of four various thicknesses which are fixed at two different positions. The design objectives such as low stress and displacement combination is obtained through the antero-lateral position with 1.8 mm implant thickness. Various material properties are assigned to cortical, cancellous, trabecular regions of the bone and to implants made up of titanium alloy. The results obtained from the Finite Element Analysis are used to evaluate the stability and suitability of the implant for that particular fracture.

Dentoalveolar fractures of the anterior maxilla usually result in a scooped out defect of the region. This causes loss of lip support and aless than optimal condition for implant placement. The present study aims to study the merits and demerits of using autogenous tibialgraft for augmenting the anterior maxillary region. The study was carried out in 10 patients with post-traumatic anterior maxillary defects.The results of using tibial bone graft are presented.

The INBONE total ankle replacement has been in use since 2005. Although studies are not available regarding its success, it is increasingly being used because of its unique design. This design features a wide modular tibial stem onto which additional components can be added to increase its length and a talar component with a modular stem. A leg holder is used with the aid of fluoroscopy in attaining alignment during insertion. The design helps the surgeon deal with severe deformity, tibial bone loss, distal tibia infarction and revision total ankle arthroplasty. This article details the techniques used for its insertion.

Background: Cancellous bone graft is frequently used during orthopedic procedures. While the iliac crest has traditionally been the most common donor site, the proximal tibia is an alternative donor site, especially for foot and ankle procedures. This study tested the null hypothesis that the histologic composition of iliac and tibial bone grafts is similar. Materials and Methods: Specimens from the iliac crest ( n = 10) and tibia ( n = 10) in excess of that needed for patients undergoing foot or ankle fusion were examined histologically. Iliac samples were taken from the anterior iliac crest. Tibial samples were harvested from the region of Gerdy's tubercle. Specimens were graded based on the percent of bone surfaces that opposed active hematopoietic marrow, with Grade I at 0%, through Grade VI at 81% to 100%. Differences between iliac and tibial grafts were evaluated with Fisher's Exact Test. Results: Iliac crest and tibial bone grafts both showed trabecular fragments with abundant osteocytes. All iliac grafts contained active hematopoietic marrow. In contrast, the medullary space of tibial grafts contained fat and little hematopoietic marrow. Nine iliac grafts were graded V or VI; whereas the ten tibial bone grafts were all graded I or II ( p = 0.0001). The difference in the numbers of samples in each group ranked as grade VI was also statistically significant ( p = 0.005). Conclusion: Iliac bone grafts contained active hematopoietic marrow, whereas quiescent medullary fat predominated in tibial grafts. Clinical Relevance: These findings raise questions about the cellular contributions of different sources of bone graft to bone healing.

Background Massive bone defects (>8 cm) will not unite without an additional intervention. They require a predictable, durable, and efficient method to regrow bone. The Ilizarov method of tension stress, or distraction osteogenesis, first involves a low-energy osteotomy1-5. The bone segments are then pulled apart, most often using an external device at a specific rate and rhythm (distraction phase), after which the newly formed bone (the regenerate) requires time for consolidation. The consolidation phase is variable and usually requires a substantially greater amount of time before the external device can be removed. Our technique of tibial bone transport over an intramedullary nail using cable and pulleys combines internal and external fixation, allowing the external fixator to be removed at the end of the distraction phase. This increases the efficiency of limb reconstruction and decreases the external-fixator-associated complications. Description The procedure begins with thorough debridement, orthogonal tibial cuts, osteotomy, and insertion of a custom intramedullary nail. A 1.8-mm steel cable is wrapped around the anterior cortex of the distal end of the transport segment and exits the skin distal to the docking site. Two standard rings are applied at the proximal and distal aspects of the leg, and 2 pulleys are attached to the ring at the ankle. The steel cable is then attached to slotted threaded rods that connect to the compression distraction rods that will pull the cable up and the bone segment down. Two Ilizarov "clickers" that rotate 0.25 mm with each "click" are the motor of the system. Once the bone transport system is removed, a custom interlocking bolt is placed to capture the transport segment. This prevents recoil of the fragment as there is a substantial amount of tension in the system. Alternatives There are no nonsurgical options for reconstruction of massive bone loss. The several alternatives for surgical reconstruction include the inducible membrane Masquelet technique; circular fixation alone with standard Ilizarov bifocal transport, hexapod bifocal transport, or trifocal transport; bone transport and then insertion of an intramedullary nail (Lengthening and Then Nailing, or LATN); and amputation2-8. Rationale The standard Ilizarov method for posttraumatic bone loss with external fixation is a well-established surgical procedure with high union rates. However, an external fixator has a high association with pin site infection, and it is cumbersome for the patient. In addition, scarring associated with the wires and half-pins as they progress down the limb is unsightly and painful. The advantage of the cable-pulley system is that the frame is used only in static mode; the cable that pulls the bone transport segment remains at the same exit point of the skin, thus limiting scarring. In addition, as soon as the distraction phase is completed, the external device can be removed. This substantially decreases the time that the external fixator needs to be in place.

The purpose of this biomechanical study was to investigate the potential effect of a nonanatomic repair of the meniscal horn attachment on the resultant circumferential tension in a large animal model and to show that the circumferential tension of the meniscus affects the local stress of the cartilage.All investigations were done in the medial compartment of porcine knees. First, the anterior horn attachment of the meniscus was mechanically separated from the surrounding tibial bone and fitted with a force transducer (n = 8). The femorotibial joint was loaded in compression at different flexion angles, and the resultant tension at the horn attachment was recorded. The measurements were done with the horn attachment at its anatomic position and repeated with the horn attachment being displaced medially or laterally by 3 mm. In the second part the local deformation of the cartilage under a femorotibial compressive load was measured at different levels of meniscal hoop tension (n = 5).A nonanatomic position of the horn attachment had a significant effect on the resultant tension (P.01). Placing the horn attachment 3 mm medially decreased the tension at the horn attachment by 49% to 73%, depending on flexion angle and femorotibial load. The opposite placement resulted in a relative increase in the tension by 28% to 68%. Lower levels of meniscal hoop tension caused increased deformation of the cartilage (P.05), indicating increased local stress.A nonanatomic position of the horn attachment strongly affects conversion of femorotibial loads into circumferential tension. There is a narrow window for a functionally sufficient repair of meniscal root tears.Although clinical inferences are limited because the specimens used were from a different species, there seems to be only a narrow window for a mechanically sufficient repair of root tears.

Aim: To investigate the biochemical parameters and bone “speed of sound” (SoS) values used in the screening for osteopenia of prematurity (OP). Material and Methods: Serial measurements of tibial bone SoS and concomitant serum calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) levels of preterm infants in postnatal week 1, 3, and 6 were studied retrospectively. Results: Fifty premature infants ≤ 35 weeks of gestational age were included in the study. A positive correlation was detected between serum P levels and SoS values at 1st and 6th week (r = 0.55, P = 0.0001 and Rho = 0.67, P = 0.0001, respectively). SoS values in postnatal week 3 were correlated with SoS values in week 1 and week 6 (Rho = 0.67, P = 0.0001 and Rho = 0.65, P = 0.0001, respectively). Serum Ca, P, and ALP levels measured in postnatal week 1 and 3 were not predictive of the subsequent risk of osteopenia. The SoS value in week 3 (≤ 2940 m/s) was predictive of the risk of osteopenia in week 6, with sensitivity of 85% and specify of 73% (Area under the curve [AUC] = 0.80, p = 0.001). Conclusions: Serum P levels were correlated with bone SoS values. Bone SoS measurements in postnatal week 3 rather than biochemical parameters was predictive of the risk of osteopenia in postnatal week 6. For this reason, screening for osteopenia can be started at postnatal week 3 in newborn units where quantitative ultrasonography (QUS) is used.

Most open fractures associated with motor-vehicle accidents are severe, and 65% to 75% of all open tibial fractures that result from motor-vehicle accidents are Gustilo type III in severity1. The exposed location of the tibia in motorcyclists was confirmed by Zettas et al., who reported that the tibia was the bone most frequently fractured during motorcycle accidents and that 19.2% of all motorcycle-related fractures were of the tibia2. The treatment of bone defects in this clinical setting can be very challenging3. To date, several bone transport techniques have been developed and are included in Ilizarov’s classification of distraction-compression osteosynthesis and related distraction-osteogenesis methods4. These techniques can be divided into three groups—monofocal, bifocal, and trifocal—on the basis of the number of distraction-compression sites5. Here we report the case of a patient in whom a tibial bone defect was treated with bifocal bone transport in two locations at the same time. We have chosen to call this technique tetrafocal bone transport . The tibial defect was bifocal, affecting both the proximal and distal metadiaphyseal regions of the tibia. We assembled a suitable Ilizarov frame to distract two separate osteotomies done in the middle fragment to fill the proximal and distal bone defects with bone transported from the middle segment. A thorough search of the literature revealed no reports on tetrafocal bone transport for tibial bone defects. The patient was informed that data concerning the case would be submitted for publication, and he consented. A forty-two-year-old man was in a motorcycle accident and presented to the emergency department of a nearby hospital with a Gustilo type-IIIB open fracture of the left tibia with bone loss. The wound was irrigated and debrided, and a Hoffmann-II external fixator (Stryker, Mahwah, New Jersey) was applied. Ischemia …

Udgivelsesdato: 2009-Dec Composite interference screws containing calcium phosphate for anterior cruciate ligament graft fixation could improve implant/bone integration and thereby reduced tunnelwidening and graft slippage. The present study investigated the effect of polylactate/hydroxyapatite interference screw (HA/PLLA) screw used for tibial graft fixation on tunnel widening and clinical outcomes compared with a metal interference screw. We hypothesized less tibial tunnelwidening with HA/PLLA screws compared to metal screws. Hundred patients with HA/PLLA screw tibial fixation was compared with 100 patients with metal screw tibial fixation. Tibial tunnel widening was measured on AP and lateral radiographs taken at 12 months follow-up. Clinical outcome was assessed by objective and subjective international Knee Documentation Committee (IKDC) scores, Noyes Sports Activity and Occupational Rating scores and KT-1000 knee laxity measurements. Tibial tunnel widening at the level of the metal screw group was 36% and 38% on AP and lateral radiographs respectively. Tunnel widening was lower in the HA/PLLA group with mean tunnel widening of 30% and 32% (p=0.012 and 0.018) on AP and lateral radiographs respectively. No differences were found for any of the clinical scores or for anterior knee laxity. The use of a polylactate/hydroxyapatite interference screw resulted in less tibial tunnel widening than a metal screw around the screw but did not affect clinical outcome or objective knee laxity.

Background: Despite the increase in the number of total knee arthroplasty revisions, outcomes of such surgery and their correlates are poorly understood. The aim of this study was to characterize patterns of functional improvement after revision total knee arthroplasty over a two-year period and to investigate factors that affect such improvement patterns. Methods: Three hundred and eight patients in need of revision surgery were enrolled into the study, conducted at seventeen centers, and 221 (71.8%) were followed for two years. Short Form-36 (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lower-Extremity Activity Scale (LEAS) scores were collected at baseline and every six months for two years postoperatively. A piecewise general linear mixed model, which models correlation between repeated measures and estimates separate slopes for different follow-up time periods, was employed to examine functional improvement patterns. Results: Separate regression slopes were estimated for the zero to twelve-month and the twelve to twenty-four-month periods. The slopes for zero to twelve months showed significant improvement in all measures in the first year. The slopes for twelve to twenty-four months showed deterioration in the scores of the WOMAC pain subscale (slope = 0.67 ± 0.21, p < 0.01) and function subscale (slope = 1.66 ± 0.63, p < 0.05), whereas the slopes of the other measures had plateaued. A higher number of comorbidities was consistently the strongest deterrent of functional improvement across measures. The modes of failure of the primary total knee arthroplasty were instrument-specific predictors of outcome (for example, tibial bone lysis affected only the SF-36 physical component score [coefficient = −5.46 ± 1.91, p < 0.01], while malalignment affected both the SF-36 physical component score [coefficient = 5.41 ± 2.35, p < 0.05] and the LEAS score [coefficient = 1.42 ± 0.69, p < 0.05]). Factors related to the surgical technique did not predict outcomes. Conclusions: The onset of worsening pain and knee-specific function in the second year following revision total knee arthroplasty indicates the need to closely monitor patients, irrespective of the mode of failure of the primary procedure or the surgical technique for the revision. This information may be especially important for patients with multiple comorbidities. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

We report the fracture of the tibial bone block after posterior cruciate ligament reconstruction using double cross pins for bone block fixation in the postoperative period. The possible reasons include the size of bone block, direction of cross pin or the quality of bone block. This case emphasizes the biomechanical properties and failure of modes of double cross pin.

(Received 6 October 2008; revised version 21 April 2009; accepted 6 November 2009)ABSTRACTThe aim of this study was to examine the effect supplementation of diet with 20 mg Cu/kg from copper sulphate (Cu-SUL) and/or copper amino acid chelate (Cu-AA) on the copper balance, bone mineralization status and growth performance of turkeys. A total of 840 one-day-old heavy Large White BIG-6 turkey males were randomly assigned to 4 groups: Cu-0, Cu-SUL, Cu-SUL/Cu-AA and Cu-AA. The results of the present study confirm the Cu-requirements for growing/fattening turkeys given by scientific bodies (e.g., NRC, INRA, GfE). The Cu unsupplemented basal diet contained 11.3 mg Cu/kg is enough for turkeys and further Cu-supplementations are not necessary. Further supplementations from inorganic and/or organic sources did not significantly improve turkeys performance and health. Plasma superoxide dismutase activity, physico-chemical properties of bone and the concentrations of Ca and P in the tibial bone were generally not affected by dietary treatment. Further Cu supplementation from inorganic and/or organic sources increase the Cu-excretion (from 808 to 1915-2164 mg per animal) and may cause additional environmental problems. KEY WORDS: copper, chelate, bone mineralization, performance, turkeys

Sixteen cases of revision total knee arthroplasty requiring the use of porous tantalum tibial cones for 2 T2A, 3 T2B, 4 T3A, and 7 T3B tibial bone defects (Anderson Orthopaedic Research Institute classification) after 13 cases of aseptic loosening and 3 cases of staged reimplantation for infection were reviewed. At an average 31 months (24-38), no patients were lost to follow-up. There were 2 cases of recurrent sepsis requiring removal of a well-fixed cone. In the remaining 14 cases, the reconstructions were functioning well with no reoperations. Radiographs demonstrated reestablishment of the joint line, neutral mechanical axis (average, 5.4 degrees of valgus), and signs of stable osteointegration into the cones. Good short-term results were achieved in complex revisions, with these new reconstructive tools.

1. Tibial bone morphology and quality was assessed at 6, 8 and 10 weeks of age in 12 broiler, 12 layer and 13 traditional lines of chickens. 2. High intraclass correlations (0.65-0.96) were estimated for tibial weight, length, width, strength, stiffness, stress radiodensity, plateau angle but not for cortical width and tibial torsion at 6 and 10 weeks of age and for weight, length, width, strength radiodensity and plateau angle at 8 weeks of age. Lower intraclass correlations (0.4-0.8) were estimated within category (broiler, layer and traditional) for weight, length, width at 6, 8 and 10 weeks, and for stiffness, stress and radiodensity at 6 and 10 weeks, and were lower (

The nose is the central part of the face and the most prominent facial feature. Augmentation rhinoplasty is one of the most exciting and arduous techniques for plastic surgeon and patient. Fourteen cases of augmentation rhinoplasty with cortical tibial bone graft are presented. An endonasal approach was used in 13 cases and an open approach in one case, with a donor site short scar (1.5 cm) in every case. The average follow up was 2 years and no significant bone resorption was observed. No remarkable complications or complications requiring surgery were noted during the follow up. The cosmetics results have been gratifying.

Magnetization transfer (MT) contrast imaging reveals interactions between free water molecules and macromolecules in a variety of tissues. The introduction of ultrashort echo time (UTE) sequences to clinical whole-body MR scanners expands the possibility of MT imaging to tissues with extremely fast signal decay such as cortical bone. The aim of this study was to investigate the MT effect of bovine cortical bone in vitro on a 3 Tesla whole-body MR unit. A 3D-UTE sequence with a rectangular-shaped on-resonant excitation pulse and a Gaussian-shaped off-resonant saturation pulse for MT preparation was applied. The flip angle and off-resonance frequency of the MT pulse was systematically varied. Measurements on various samples of bovine cortical bone, agar gel, aqueous manganese chloride solutions, and solid polymeric materials (polyurethane) were performed, followed by preliminary applications on human tibial bone in vivo. Direct on-resonant saturation effects of the MT prepulses were calculated numerically by means of Bloch's equations. Corrected for direct saturation effects dry and fresh bovine cortical bone showed "true" MTR values of 0.26 and 0.21, respectively. In vivo data were obtained from three healthy subjects and showed MTR values of 0.30 +/- 0.08. In vivo studies into MT of cortical bone might have the potential to give new insights in musculoskeletal pathologies.

Low-level laser therapy (LLLT) is a biophysical form of intervention in the fracture-repair process, which, through several mechanisms, accelerates the healing of fractures and enhances callus formation. The effect of laser on fracture healing is controversial. Some authors affirm that LLLT can accelerate bone formation by increasing osteoblastic activity. The objective of our study was to evaluate the effect of laser therapy on fracture healing. Thirty rabbits were subjected to tibial bone open osteotomies that were stabilized with external fixators. The animals were divided into two study groups: laser group and control group. Callus development and bone mineral density were quantitatively evaluated by CT; the animals were then killed and the fractures were assessed for biomechanical properties. The results demonstrated that the increasing rate of bone mineral density was higher in the laser (L) group than in the control (C) group. CT at 5 weeks revealed a mean callus density of 297 Hounsfield units (HU) for the control group and 691 HU for the L group, which was statistically significant (P = 0.001). In the L group, the mean recorded fracture tension was 190.5 N and 359.3 N for healed and intact bones, respectively, which was statistically significant (P < 0.001). The result of the study showed that the use of laser could enhance callus development in the early stage of the healing process, with doubtful improvement in biomechanical properties of the healing bone; therefore, laser therapy may be recommended as an additional treatment in non-union fractures in humans.

Surgical procedures for double-bundle reconstruction of anterior cruciate ligament, which currently use semitendinous and gracilis tendon grafts, have been described in the last decade. Most of the techniques utilize twice the hardware used in single-bundle reconstructions. We report an original anterior cruciate ligament double-bundle reconstruction technique using semitendinous and gracilis tendon grafts, maintaining their tibial bone insertions with two tibial and two femoral tunnels. A simplified and precise outside-in femoral drilling technique is utilized, and the graft fixation is made utilizing only two interference screws.

Purpose The purpose of this study was to evaluate the clinical results of arthroscopic treatment of tibial avulsion fracture of the posterior cruciate ligament (PCL) by suture fixation technique through a single bone tunnel. Methods We arthroscopically treated 28 patients (mean age, 35.3 years) with PCL avulsion fractures using 2 posteromedial portals. The bony fragment was sutured by use of a suture hook and was then reduced into the top of the tibial bone tunnel created from the anterior tibial cortex to the bottom of the fracture bed. Slight depression of 1 to 3 mm of the osseous fragment was achieved. We followed up 24 cases for more than 2 years. Results The fracture usually healed at 6 to 12 weeks (mean, 2.8 months) after surgery. At the last follow-up, all patients achieved normal range of motion of the knees, except for 2 patients who had 5° and 10° terminal flexion limitations of the involved knees, respectively. KT-1000 examination (MEDmetric, San Diego, CA) showed that the side-to-side difference was 0 to 2 mm in 23 patients and 3 mm in 1 patient, with a mean of 0.7 ± 0.8 mm. The Lysholm score was 92 to 100, with a mean of 95.2 ± 2.3. On the basis of the International Knee Documentation Committee knee examination form, the results were graded as normal in 20 patients and as nearly normal in the other 4. The mean Tegner score was 6.8 ± 0.4 preoperatively and 6.6 ± 0.5 at the last follow-up ( P = .23). Conclusions The single–tibial tunnel technique seemed not only to simplify the procedure but also to facilitate slight depression of the bony fragment, which might have been useful to restore normal tension of the PCL. Clinically, this technique was reproducible and effective. Level of Evidence Level IV, therapeutic case series.

Background: With the rapid urbanization of Vietnam, living on boats has come to be associated with underprivileged socioeconomic status, and there are major concerns regarding the health of children living under such conditions. Bone development is a critical concern in children because the foundation for skeletal health is established early in life. We evaluated the bone properties of children living under underprivileged conditions on boats in Hue City, Vietnam, with respect to a number of household factors. Methods: One hundred and twenty children aged 7-11 years selected randomly from households living on boats in Hue were included in this study. Tibial and radial speed of sound (SOS) were measured by non-invasive quantitative ultrasonometry. Socioeconomic profiles, health promotion proficiency, and nutritional intake of households were assessed by structured interview. The bone properties of 60 children aged 7-11 living on land were also assessed as controls. Results: The Z-scores of tibial and radial SOS of boat children were -0.16 ± 0.89 and -0.24 ± 0.75 (mean ± SD), respectively. Tibial SOS exhibited a significant correlation with radial SOS (r = 0.39, P < 0.01). Among the household factors examined, the educational level of fathers (P < 0.05) and the health promotion proficiency (P < 0.05) of households exhibited positive associations with the tibial bone properties of the children. The tibial and radial SOS of boat children were lower than those of children living on land (P = 0.001 and P = 0.086, respectively). Conclusion: The results of the present study revealed the underdevelopment of bone properties in children living on houseboats, which was correlated with their living conditions.

We present here the preliminary results obtained with arthroscopic tightening of the anterior cruciate ligament. Six patients underwent the technique. Four had had prior ligamentoplasty, two had sequelae of tibial spine fractures. Laxity persisted in all cases. The transplant or the ligament were continuous and insertion points were well-positioned. The procedure consisted in using a trephine to bore the tibial bone at the "foot" of the ligament or transplant in order to tighten the ligament. There was no evidence of instability after the arthroscopic tightening procedure. Mean pre- and postoperative differential anterior drawer values were successively 9.2 and 3.9 mm. For native or reconstructed anterior cruciate ligaments, which are continuous and well-positioned but not loose, arthroscopic tightening spares the need for ligament transplant and appears to be free of specific morbidity.

Aim: The use of autologous bone is a good option for bone grafts in implantology. The purpose of this study was to present advantages in harvesting the proximal tibial cancellous bone as an alternative in the sinus floor lifting procedure, seeking future installation of osseointegraded implants. Materials and methods: Between 2002 and 2006, 19 patients were attended, with age between 41 and 77, being 9 males and 10 females, in order to lift the maxillary sinus floor. The approach to the donor site was medial, because of the fact that this method brings minor risk of injury to anatomical structures. Results: All cases allowed the installation of osseointegraded implants. Only minor complications occurred, such as local ecchymosis and ecchymosis extending to foot. In all cases, ambulation was immediate. Conclusions: A good amount of bone could be harvested; scarce pain symptomatology was detected, and risk of complications could be considered very low in the donor site.

The purpose of this study was twofold: to evaluate the radiological and clinical results of 33 total knee arthroplasties (TKA) implanted between January 1993 and March 2005, to replace failed medial unicompartmental knee arthroplasty (UKA), and to develop a strategy to deal with bone defects in the tibial plateau. Failure was due to: tibial loosening (15 cases), femoral loosening (five cases), femoral and tibial loosening (two cases), polyethylene wear (five cases), lateral compartment osteoarthritis (two cases), patellofemoral osteoarthritis (two cases), laxity and PE dislocation (one case), and sepsis in one case. In 12 cases the tibial bone defect was filled with a metallic wedge, in seven we used an allograft (femoral head), and in one we used both. We report the results of 27 cases (five patients died and one was lost to follow-up). The mean follow-up was 73+/-41.7 months (range, 8-153) and the global IKS score was 166.72+/-21.3 points (range, 128-200). X-rays of the eight allografts showed osteointegration in all cases and no radiolucency was noted.

Recent reports have suggested that procedures using bone grafts from the tibia shorten operating time and reduce postoperative discomfort. Tibial grafts are thought to be less invasive than conventional iliac grafts, and we have obtained favourable results with tibial grafts. However, this report is of a 54-year-old woman who sustained a tibial fracture on the donor side in a fall after harvesting for the tibial graft. This suggests that although extraction of bone from the tibia is less invasive than extraction from the iliac crest, there is a need for a mandatory period of rest and reduced effort to allow bone regeneration at the donor site with the use of bone graft substitutes.

The aim of this study was to compare the results of two different methods of posterolateral corner reconstruction (fibular head tunnel versus tibial tunnel), performed at the same time as a posterior cruciate ligament reconstruction. Between January 1999 and October 2003, 47 patients underwent tensioning of a remnant posterior cruciate ligament and anterolateral bundle reconstruction along with a posterolateral corner reconstruction using a fibular head bone or tibial bone tunnel. Thirty-nine patients determined to be eligible were enrolled in this retrospective study after a minimum follow-up duration of 2 years. The average duration of follow-up was 35.3 months (range 24-70 months). Satisfactory results were achieved in 32 patients (82%) according to the International Knee Documentation Committee(IKDC) scores, and 29 patients (74%) had restored external rotational stability. The fibular head tunnel was superior to the tibial tunnel method in terms of operation time (43.0 +/- 15.7 vs. 66.6 +/- 9.4 min, respectively, P0.001) and improved rotational stability (85 vs. 65%, respectively, P = 0.007). However, there were no significant differences seen in anteroposterior stability and clinical assessments [Orthopädische Arbeitsgruppe Knie (OAK) P = 0.277 and IKDC scores P = 0.564]. In grade 2 chronic posterolateral rotatory instability with little or no varus instability associated with injury to the posterior cruciate ligament, a posterolateral reconstructive procedure with a single sling through the fibular tunnel offers advantages of less surgical morbidity and operation time, as well as better rotational stability, over reconstruction through the tibial tunnel.

BACKGROUND An overview of prospective studies on cementless and cemented primary knee joint endoprosthetics carried out between 1988 and 2004 reveals that the aseptic tibial loosening rate of cemented prostheses implanted with fixed meniscal bearings amounts to 2-6% within a period of 4-14 years, while cementless implanted prostheses show loosening rates of up to 28% within a period of 4-10 years. If these results arise from a lack of proper initial osseointegration as a result of insufficient primary stability, and how this is influenced by the tibial bone quality and the tibial fixation procedure has not yet been investigated. MATERIALS AND METHODS Tibial plateaus were press-fit implanted, both screwed and unscrewed, into each of six pairs of tibial heads from corpses. Stability testing was conducted applying eccentric axial load, shear and torsion. RESULTS The average amounts of relative movement at the medial and lateral plateau are clearly different in the screwed version and the unscrewed version when loaded axially, but the difference was significant (p = 0.016) only at the medial plateau. Relative movements under shear and torsion showed no significant differences. The bone density of the tibial metaphyses had no significant effect on the primary stability of the cementless implanted tibial plateau. CONCLUSION When using cementless knee endoprostheses, the fixation of the tibial plateau with screws--in addition to a flawless press-fit and form-fit customization of the tibial head--appears indispensable for guaranteeing proper osseointegration under physiological axial loads.

Background: Tibial bone loss is frequently encountered at the time of revision total knee arthroplasty, and the outcome of the revision often depends on the management of this bone deficiency. We examined the clinical and radiographic outcomes of a series of revision total knee arthroplasties in which a structural allograft had been used to reconstruct a tibial bone defect encountered at the time of the revision procedure. Methods: From January 1985 through September 1999, one surgeon performed revision arthroplasty in forty-nine knees (forty-seven patients) with a severe tibial bone defect. The reasons for the revisions included polyethylene wear and osteolysis in twenty-four knees, aseptic loosening in seventeen knees, infection in five knees, and failure for another reason for three knees. Structural allograft was used alone in thirty-five knees and in conjunction with a tibial augment in fourteen knees. The mean age of the patients at the time of the revision arthroplasty with the allograft was sixty-seven years. The patients were assessed clinically with use of the Knee Society score and radiographically. Results: The status of the implant was known for forty-six of the forty-nine knees in this study. It was unknown for one patient (one knee) who was lost to follow-up and for two patients (two knees) who died less than five years postoperatively. Four revision procedures in four patients failed and required a reoperation. Two of the failures were due to infection. At a mean of ninety-seven months postoperatively, the mean Knee Society clinical score was 84 points for the knees that had not had a reoperation due to failure. The mean arc of motion improved from 87° preoperatively to 103° at the most recent follow-up evaluation. Histological evaluation of specimens retrieved at two autopsies demonstrated graft union to host bone. Conclusions: A structural allograft provides a stable and durable reconstruction of a tibial bone deficiency. At a mean of ninety-five months postoperatively, we found no instance of graft collapse or aseptic loosening associated with the structural allograft. We recommend the use of a structural allograft for the management of severe tibial bone deficiency at the time of revision total knee arthroplasty. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Surgical reconstruction of tibial bone defects presents a significant challenge for the orthopaedic surgeon. The bone defect is usually a result of high-energy trauma or of debridement for osteomyelitis. These defects are often accompanied by major soft-tissue injuries which limit the functional outcome independently of the actual loss of tibial bone. Conventional bone graft and free vascularised fibular grafting are methods of treatment of large defects after severe open fractures. The Ilizarov technique of segmented bone transport of the tibia involving a circular ring external fixator has also been used for tibial defects, with acceptable outcome. Ipsilateral fibular transfer with the Ilizarov frame is another alternative treatment for massive tibial bone loss, and yields favourable results. The main disadvantages of the Ilizarov method are the lengthy treatment time and the long-term disability. Bone transport either over unreamed