Constitutional varus knee due to tibial deformity is common and represents a good indication for high tibial osteotomy in Japanese population: Consideration of 1010 knees.

PURPOSE: This study aimed to elucidate the characteristics of varus knee deformities in the Japanese population, prevalence of various around knee osteotomy procedures and influence of femoral and tibial bowing. METHODS: Varus knee deformity was defined as a weight-bearing line ratio of <50%. A total of 1010 varus knees were selected from 1814 varus knees with weight-bearing full-length radiographs, obtained at two facilities, based on exclusion criteria. Various parameters were measured, and around knee osteotomy simulations based on the deformity centre were conducted using digital planning tools. Bowing of the femoral and tibial shafts was measured, with bowing defined as follows: ≤ -0.6° indicating lateral bowing and ≥ 0.6° indicating medial bowing. Statistical analysis was performed to investigate age-related correlations and their impact on surgical techniques. RESULTS: The study revealed that the proximal tibia was the centre of deformity in Japanese varus knees (42.8%), and high tibial osteotomy was frequently indicated (81.6%). Age demonstrated a mild correlation with femoral shaft bowing (r = -0.29), leading to an increase in the mechanical lateral distal femoral angle and to a decrease in the hip-knee-ankle angle and weight-bearing line ratio (r = -0.29, 0.221, 0.219). The tibial shaft bowing was unaffected by age (r = -0.022). CONCLUSION: A significant proportion of Japanese individuals with varus knees exhibit a deformity centre located in the proximal tibia, making them suitable candidates for high tibial osteotomy. No age-related alterations were discerned in tibial morphology, indicating that the occurrence of constitutional varus knees is attributable to tibial deformities in the Japanese patient cohort. LEVEL OF EVIDENCE: Level IV.

Impact of source water quality on total organic carbon and trihalomethane removal efficiency in a water treatment plant: A case study of Upper Awash, Ethiopia.

This study addresses the limited understanding of factors affecting the efficiency of water treatment plants in reducing trihalomethane (THM) formation through total organic carbon (TOC) removal, highlighting significant challenges in improving treatment effectiveness. The aim of this study was to examine the influence of water quality on the efficiency of water treatment plants to remove TOC and reduce THM formation. Linear regression and correlation analyses were conducted to examine the relationship between water quality parameters and THM concentrations. The results showed that there was a negative relationship between turbidity, metals, and TOC concentration with TOC removal efficiency. Positive correlations were found between parameters and the formation of THMs in water. Of these parameters, water temperature was observed to have relatively less influence on THM formation. It was observed that seasonal variations in water quality affect the efficiency of TOC removal and THM content in treated water. THM levels in chlorinated water were found to be within the permissible range of the World Health Organization's drinking water quality guidelines. However, it is still important to maintain continuous monitoring and take measures to reduce THMs. The model demonstrated a strong correlation (R2 = 0.906) between predicted and measured THM values.

Effect of Solitary Osteochondroma on Alignment and Length in the Lower Extremities.

BACKGROUND: There is a lack of information about the effects of untreated solitary osteochondroma (SO) on longitudinal growth of the lower extremities in children and adolescents. This study aimed to assess the coronal alignment and length of the lower extremity in patients with SO around the knee and to identify the factors related to the development of deformities. METHODS: We retrospectively reviewed 111 patients diagnosed with SO around the knee. The patients were classified into 2 groups depending on the location of the SO: 51 in the distal femur and 60 in the proximal tibia. Characteristics of the lesions, such as type, location, size, and distance from the joint line, were determined. Radiographic analysis of the lower limbs included mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, whole-leg length, femoral length, and tibial length. RESULTS: The mean age at the time of diagnosis was 12.3±3.4 years. No statistically significant differences were found between the affected and contralateral sides for mechanical lateral distal femoral angle and mechanical medial proximal tibial angle in either the distal femur or the proximal tibia groups. In patients with femoral lesions, the femoral and whole-leg lengths were significantly shorter on the affected side than on the unaffected side ( P <0.001 and 0.002, respectively), and the mean differences were 2.1±3.6 and 2.1±4.4 mm, respectively. Univariate logistic regression analysis did not reveal any factors associated with limb length discrepancy (LLD). In patients with tibial lesions, no statistically significant differences were found in LLD. CONCLUSIONS: SOs around the knee did not cause clinically significant deformity of the lower extremity. However, in contrast to proximal tibia lesions, SO in the distal femur was associated with the shortening of the affected limb. Consideration should be given to the development of LLD in skeletally immature children with SO in the distal femur. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Osteogenic organoid for bone regeneration: Healing of bone defect in congenital pseudoarthrosis of the tibia.

BACKGROUND: Congenital pseudoarthrosis of the tibia (CPT) is an uncommon disease associated with failure to achieve bone union and recurrent fractures. There is evidence showing that CPT is associated with decreased osteogenesis. Based on the capacity of mesenchymal stromal cells (MSCs) to induce osteogenesis, we develop an osteogenic organoid (OstO) constituted by these cells, and other components of the bone niche, for inducing bone formation in a child diagnosed with CPT. AIM: To evaluate the capacity of an OstO to induce bone formation in a patient with CPT. METHODS: The OstO was fabricated with allogeneic bone marrow MSCs from a healthy donor, collagen microbeads (CM) and PRP clot. The CM and PRP function as extracellular matrix and scaffolds for MSC. The OstO was placed at the site of non-union. Internal and external fixation was placed in the tibia. Radiological evaluation was performed after MSCs transplantation. RESULTS: After 4 months of MSCs transplantation, radiographic imaging showed evidence of osteogenesis at the site of CPT lesion. The tibia showed bone consolidation and complete healing of the non-union CPT lesion after 6 months. Functional improvement was observed after 1 year of MSC transplantation. CONCLUSIONS: The OstO is a bone-like niche which promote osteogenesis in patients with failure in bone formation, such as CPT. To our knowledge, these results provide the first evidence showing CPT healing induced by an OstO constituted by allogeneic MSCs. Future studies incorporating a larger number of patients may confirm these results.

The Perils of Sleeper Plates in Multiple Hereditary Exostosis: Tibial Deformity Overcorrection Due to Tether at Empty Metaphyseal Hole.

BACKGROUND: Hemi-epiphysiodesis is the mainstay of treatment for angular deformities at the knee in children with multiple hereditary exostosis (MHE). Upon deformity correction, the metaphyseal screw may be removed from the hemi-epiphysiodesis plate, the sleeper plate technique, with anticipated reimplantation of the metaphyseal screw should the original deformity recur. The aim of the present study is to compare the incidence of complications with the sleeper plate technique with complete plate removal in an MHE cohort. METHODS: Patients under the age of 18 with MHE who underwent hemi-epiphysiodesis of the proximal tibia and/or distal femur between February 1, 2016, and February 6, 2022 with a minimum 2-year follow-up or follow-up to skeletal maturity were identified via ICD-10 codes. Patient charts and radiographic images were reviewed to assess for the bone(s) treated, the use of sleeper plates, and whether any complication occurred, including overcorrection from bony ingrowth at the empty holes or deformity recurrence. RESULTS: In 13 patients, 19 knees underwent hemi-epiphysiodesis at 30 sites; 13 distal femoral and 17 proximal tibial. Of 30 plates, 18 (60%) were removed completely upon deformity correction and 3 (10%) did not require removal due to skeletal maturity. Four of 13 (30.8%) femoral plates and 5 of 17 (29.4%) tibial plates were left as sleeper plates. All 5 tibial sleeper plates developed bony ingrowth into the empty metaphyseal screw hole, which led to unintended progressive deformity overcorrection. In the majority of cases, the deformity was addressed by the removal of the plate and exophytic bone and hemi-epiphysiodesis on the other side of the affected proximal tibia with subsequent resolution of the deformity. CONCLUSIONS: All tibial sleeper plates developed bony ingrowth into the screwless metaphyseal hole. The bony ingrowth functioned as a tether, resulting in progressive deformity overcorrection. Sleeper plates should be avoided at the proximal tibia in patients with MHE, and extreme caution should be exercised when considering this technique at the distal femur or other sites. LEVELS OF EVIDENCE: Level III-retrospective comparative study.

Accuracy of the hexapod external fixator in treating tibial angular deformities with or without limb length discrepancy: a retrospective study.

OBJECTIVE: Hexapod external fixator systems allow simultaneous deformity correction in multiple planes as well as limb lengthening. The aim of this study is to evaluate the accuracy of a hexapod frame (smart correction frame) in different types of tibial deformities requiring correction with or without lengthening. METHODS: A total of 54 tibial angular deformities and limb length discrepancies operated with a hexapod frame between January 2015 and January 2021 were classified into four groups: "Group A ( n  = 13): only lengthening," "Group B ( n  = 14): lengthening and uniplanar correction," "Group C ( n  = 16): only uniplanar correction," and "Group D ( n  = 11): biplanar correction." The accuracy of angular deformity correction/lengthening was calculated by dividing the actual correction/lengthening achieved after frame removal by the preoperative planned lengthening/correction. RESULTS: The lengthening accuracy in Group A and Group B was 96.3 ±â€…7.1% and 95.7 ±â€…5.9%, respectively ( P  = 0.685). The angular deformity correction accuracy was 85.1 ±â€…9.9% for Group B, 85.2 ±â€…13.9% for Group C, and 80.2 ±â€…18.4% for Group D ( P  = 0.852). A revision program was performed in six cases (1 in Group B, 1 in Group C, and 4 in Group D) for full correction of the deformities. CONCLUSION: The accuracy of tibial lengthening is high with the hexapod frame and is minimally affected by simultaneous deformity correction; however, the accuracy of angular correction slightly reduces as the deformity becomes more complex. Surgeons should be aware that reprogramming may be required after complex deformity correction.

Hemiepiphysiodesis for Lower Extremity Coronal Plane Angular Correction in the Distal Femur and Proximal Tibia in Children With Achondroplasia.

BACKGROUND: Achondroplasia is the most prevalent form of skeletal dysplasia, affecting more than 250,000 individuals. Lower extremity angular deformities, particularly genu varum, are common in children with achondroplasia, often resulting in pain and limitation of function. The authors aim to determine the utility of lower extremity growth modulation with hemiepiphysiodesis in children with achondroplasia for correction of coronal plane deformities about the knee. METHODS: The authors performed a retrospective chart review of a single center from 1/1/2000 to 12/31/2020 to identify pediatric patients with achondroplasia treated with hemiepiphysiodesis as their initial procedure at the distal femur and/or proximal tibia. Patients with adequate records and who had completed their treatment were included. Data collected included duration of treatment, complications, need for osteotomy, and radiographic measurements including initial and final mechanical axis deviation, knee mechanical axis zone, mechanical lateral distal femoral angle and medial proximal tibia angle. RESULTS: Ten patients with 17 limbs met our criteria. Nine patients (15 limbs) were treated for genu varum and 1 patient (2 limbs) was treated for genu valgum. Prior to treatment, the mechanical axis fell in zone 3 in 59% of limbs and zone 2 in 41%. Average correction in mechanical axis deviation was 26.1 mm. Average change in mechanical lateral distal femoral angle was 10.3 degrees per limb, and average change in medial proximal tibia angle was 7.1 degrees per limb. Average treatment duration was 909 days. At final follow up, 81% (14/17) of limbs had the mechanical axis in zone 1, with the remaining 18% (3/17) in zone 2. No patient/limb underwent subsequent distal femur or proximal tibia osteotomy for coronal plane alignment. CONCLUSIONS: Children with achondroplasia can successfully be treated with hemiepiphysiodesis to correct coronal plane deformities at the distal femur and proximal tibia. Using this technique, no patient in our series required an osteotomy for genu varum/valgum. LEVEL OF EVIDENCE: Therapeutic level IV, Case series.

Outcomes of Limb Lengthening With Computer-assisted Hexapod External Fixators in the Treatment of Fibular Hemimelia.

BACKGROUND: Fibular hemimelia (FH) represents the most common deficiency of the long bones and is associated with multiple deformities. Reconstructive treatment with external fixators in FH restores normal lower extremity alignment and length with plantigrade feet for a balanced and effective gait. The aim of this study is to evaluate the outcomes of lower limb lengthening and simultaneous tri-plane deformity correction with a computer-assisted hexagonal external fixator in children with FH. METHODS: A retrospective review was performed for FH cases treated with a computer-assisted hexagonal external fixator in a tertiary referral center. Leg length discrepancy (LLD), interphyseal angles, tibiocalcaneal distances, healing index (HI), and callus shapes were analyzed for radiologic evaluation, and the Pediatric Quality of Life Inventory (PedsQL) was used for functional assessment. Limbs with HI <50 days/cm, PedsQL >75, and without regenerate fractures were considered successful lengthenings. RESULTS: Twenty-four limbs of 23 patients were included. The limbs were lengthened for a mean of 7.24 cm (range, 4.7 to 15.6). The initial LLD of 5.6 cm (range, 0.5 to 19 cm) increased to 1.7 cm (range, 0.1 to 6 cm), and the mean interphyseal angle was 12.7 degree (range, 1.5 to 54.2 degree), tibiocalcaneal distance was 0.85 cm (range, 0.1 to 1.7) at final follow-up. The most common regenerated bone morphology was cylindrical, as seen in 11 limbs (45.8%). The average PedsQL score was 83.5 (range, 69.5 to 96.7). Sixteen limbs (66.7%) had successful lengthening at their first, and 4 limbs (80%) had successful lengthening at their second surgeries. Seven limbs had complications requiring surgical intervention (29.1%), with 3 (12.5%) regenerate fractures after external fixators removal. CONCLUSIONS: Limb reconstruction with computer-assisted hexapod fixators is a successful and reliable option for the treatment of LLD in FH, and patients demonstrate good functional outcomes. Surgeons should be aware of potential complications and should utilize prophylactic measures when necessary. LEVELS OF EVIDENCE: Level III, retrospective comparative study.

Congenital Pseudarthrosis of the Tibia: Long-term Outcome of Treatment With Intramedullary Vascularized Fibular Graft Combined With Ilizarov Distraction.

BACKGROUND: Late presenting cases of congenital pseudarthrosis of the tibia, are further complicated with severe shortening. Limb length discrepancy (LLD) cannot be corrected by vascularized fibular grafting and the use of Ilizarov distraction is associated with a high rate of complications. The aim of this study was to report the long-term follow-up of a combined technique previously published under the name "telescoping vascularized fibular graft". MATERIALS AND METHODS: Eleven patients operated at an average age of 10.2±3.2 years were reviewed. All cases were Crawford type IV affected by neurofibromatosis 1. Nine patients had an average of 4.3 previous operations. Preoperative LLD averaged 7.9±2.5 cm. RESULTS: Follow-up averaged 10±5.4 years. Seven cases (63.6%) reached skeletal maturity before final follow-up. Primary union was achieved in all cases after an average of 7.2±1.3 months. Full weightbearing was possible after an average of 10.6±2.2 months. Recurrent stress fractures occurred in 9 cases (81.8%) and healed with casting in 6 cases and required internal fixation in 3 cases. Eight cases (72.8%) developed tibial shaft deformities, mainly procurvatum that required corrective osteotomy in 2 cases. Final LLD averaged 2.7±1.3 cm. Complete tibialization of the graft was achieved after an average of 17.0 ± 3.6 months. Valgus deformity of the ipsilateral ankle averaged 12.4 degrees±7.5. CONCLUSION: The presented technique avoids osteotomy of the diseased bone and allows simultaneous treatment of the pseudarthrosis and correction of shortening. Compared with conventional bone transport, it requires shorter time of frame application and therefore better patient tolerability because there is no waiting for consolidation of the regenerate. The dis-impaction of the doweled fibula occurs proximally, allowing the less active site located at the distal aspect of the pseudarthrosis to heal without displacement. A shortcoming of the presented technique is the more propensity for axial deviation and refractures that seldom require surgery. LEVEL OF EVIDENCE: Level-IV.

Predicting Success of Deformity Correction With Tension Band Plating in Early-Onset Tibia Vara.

BACKGROUND: Angular deformity correction with tension band plating has not been as successful in early-onset tibia vara (EOTV) as it has been in other conditions. Our hypothesis is that perioperative factors can predict the success of lateral tibial tension band plating (LTTBP) in patients with EOTV. METHODS: A retrospective review was performed at 7 centers evaluating radiographic outcomes of LTTBP in patients with EOTV (onset <7 y of age). Single-event tibial LTTBP outcome was assessed through medial proximal tibial angle (MPTA). The final limb alignment following comprehensive limb growth modulation (CLGM), which could include multiple procedures, was assessed by mechanical axis zone (MAZone), mechanical tibio-femoral angle (mTFA), and mechanical axis deviation (MAD). Preoperative age, weight, deformity severity, medial physeal slope, and Langenskiöld classification +/- modification were investigated as predictors of outcome. Success was defined as the correction or overcorrection to normal age-adjusted alignment. The minimum follow-up was 2 years except when deformity correction, skeletal maturity, or additional surgery occurred. RESULTS: Fifty-two patients with 80 limbs underwent 115 tibial LTTBP procedures at a mean age of 5.3 y, including 78 primary, 21 implant revisions, and 15 reimplantations for recurrence. Tibial LTTBP resulted in a mean change of +8.6 o in MPTA and corrected 53% of tibias. CLGM resulted in MAD correction for 54% of limbs.Univariate analysis showed that success was best predicted by preoperative age, weight, MPTA, and MAD. Multivariate analysis identified that preoperative-MPTA/MAD and preoperative-weight<70 kg were predictive of MPTA and MAD correction, respectively. The probability of success tables are presented for reference. CONCLUSION: Successful correction of MPTA to age-adjusted norms following a single-event LTTBP occurred in 53% of tibias and was best predicted by preoperative-MPTA and preoperative body weight <70 kg. Comprehensive growth modulation corrected limbs in 54%. The probability of correction to age-adjusted MAD is best estimated by preoperative-MAZone 1 or 2 (MAD ≤40 mm). Limbs with preoperative-MAD>80 mm improved, but ultimately all failed to correct completely with CLGM. Osteotomy may need to be considered with these severe deformities. While modified Langenskiöld classification and medial physeal slope have been shown to predict the outcome of osteotomy, they were not predictive for LTTBP. Change in MPTA was common after physeal untethering. LEVEL OF EVIDENCE: Level-III.

Clinical study of a new type of telescopic rod for the treatment of congenital pseudarthrosis of the tibia in children.

The purpose of this study was to investigate the initial efficacy of a new telescopic rod in the treatment of congenital pseudarthrosis of tibia (CPT) in children. A new type of telescopic rod for children was designed and its clinical results were evaluated. There were nine cases of CPT on the right and six cases on the left; there were six females and nine males. The average age at operation was 35.5 months. There were 12 cases with neurofibromatosis type 1 and 4 cases with proximal tibial dysplasia. The initial healing of tibial pseudarthrosis, proximal tibial valgus deformity, tibial length, ankle valgus, ankle function, and intramedullary rod displacement were evaluated during follow-up. All 15 cases were followed up for an average of 18.2 months, 14 cases achieved initial healing, with an average healing time of 4.3 months. Ten cases had unequal lengths of the tibia, with an average of 0.9 cm. Proximal tibial valgus occurred in seven cases and ankle valgus occurred in one child. The average range of motion of the ankle joint was 23° and the average plantar flexion was 42°. The average extension of the new telescopic rod was 1.6 cm. The displacement of the telescopic rod occurred in seven cases, there was no epiphyseal plate tethering and re-fracture. The new children's telescopic rod has a reasonable design and can extend with the growth of tibia. There are no complications of epiphyseal plate tethering and re-fracture. It provides a new choice of intramedullary fixation for the treatment of CPT.

Femoral Deformity in Tibia Vara and Its Response to Growth Modulation.

BACKGROUND: While tibia vara is a disorder of the proximal tibial physis, femoral deformity frequently contributes to the overall limb malalignment. Our purpose was to determine how femoral varus deformity in tibia vara responds to growth modulation, with/without lateral tension band plating (LTBP) to the femur. METHODS: One-hundred twenty-seven limbs undergoing LTBP for tibia vara were reviewed. All had tibial LTBP and 35 limbs also had femoral LTBP for varus. Radiographs were measured for correction of the mechanical lateral distal femoral angle (mLDFA) and mechanical axis deviation (MAD). Preoperative-femoral varus was defined with an age-adjusted guide: mLDFA >95 degrees for 2 to below 4 years and mLDFA >90 degrees for 4 to 18 years. The 35 limbs having femoral LTBP were compared with 50 limbs with femoral varus and no femoral LTBP. In addition, 42 limbs that did not have preoperative-femoral varus were followed. Patients with early-onset (below 7 y) tibia vara were compared with those with late-onset (≥8 y). Outcome success was based on published age-adjusted mLDFA and MAD norms. RESULTS: Following femoral LTBP, the mean mLDFA decreased from 98.0 to 87.1 degrees. All femurs had some improvement, with 28/35 femurs (80%) achieving complete correction. One limb, with late follow-up, overcorrected, requiring reverse (medial) femoral tension band plating.For the 50 limbs with femoral varus and only tibial LTBP, 16/22 limbs (73%) with early-onset and 11/28 limbs (39%) with late-onset completely corrected their femoral deformities. If the limb had preoperative-femoral varus, femoral LTBP statistically correlated with successful mLDFA correction and improvement of MAD, only in the late-onset group.Forty-two limbs, without preoperative-femoral varus, had no change in their mean mLDFA of 87 degrees. However, 4 femurs (10%) ended with posttreatment varus. CONCLUSIONS: Femoral LTBP is effective in correcting femoral varus deformity in the tibia vara. For femoral varus associated with late-onset tibia vara, femoral LTBP should be considered. Those that had femoral LTBP had statistically more successful femoral and overall limb varus correction. However, in early-onset tibia vara, with associated femoral varus, observation is warranted because 73% of femurs are corrected without femoral intervention. This study was underpowered to show additional improvement with femoral LTBP in the early-onset group. Even limbs with normal femoral alignment, should be observed closely for the development of femoral varus, during tibial LTBP treatment for tibia vara. LEVEL OF EVIDENCE: Level III.

Genomic sequencing in a cohort of individuals with fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome.

Fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome (MIM 246570) is a rare disorder characterized by specific skeletal findings (fibular aplasia, shortened or bowed tibia, and oligosyndactyly of the foot and/or hand). Typically, no other anomalies, craniofacial dysmorphism, or developmental delays are associated. Here we report three unrelated individuals with limb anomalies consistent with FATCO syndrome who have been followed clinically for 5 years. Genetic testing of previously reported individuals with FATCO syndrome has not revealed a genetic diagnosis. However, no broader sequencing approaches have been reported. We describe the results of the three individuals with FATCO syndrome from exome and genome sequencing, all of which was nondiagnostic. Our study suggests that FATCO syndrome is not the result of a simple monogenic etiology.

Guided growth for coronal lower limb deformities in skeletal dysplasia.

Coronal angular deformities of the lower limbs are common in young children with skeletal dysplasia . The guided growth technique has been applied to correct deformities in children, but there are few comprehensive reports on the effectiveness of the procedure in skeletal dysplasia. We reviewed 44 limbs of 22 patients with various types of skeletal dysplasias who underwent guided growth surgery. Fifteen varus and 29 valgus limbs were treated with 102 epiphysiodesis. The average age at surgery, at implant removal, and at the latest examination was 10.4 ± 3.6 years, 11.8 ± 3.7 years and 14.1 ± 4.4 years, respectively. The mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (mMPTA), lateral distal tibial angle (mLDTA) and mechanical axis deviation (MAD) were measured from standing anteroposterior radiographs of both lower limbs. The mLDTA, mMPTA and MAD were successfully improved after surgery. Moderate or severe deformities were observed in 100% of the varus and 83% of the valgus limbs preoperatively, whereas only 14% of the varus and 20% of the valgus limbs had residual deformities at the latest examination. Correction of deformities was limited in some older children. Fifteen limbs (34%) required repeated implantations due to recurrence or inverted deformity. The guided growth surgery is effective in correcting coronal angular deformities in children with skeletal dysplasia with a limited risk of complications. The timing of surgery and implant removal is critical in obtaining satisfactory correction and preventing recurrence or inverted deformities.

Vasculogenic gene therapy: No role for revitalization of structural bone allografts.

Segmental bone defects are often performed with cryopreserved allografts. They provide immediate stability, but risk nonunion, infection and late stress fracture. Improving the rate and extent of bone revitalization may improve results. Angiogenesis from surgically placed arteriovenous (AV) bundles improves bone blood flow and vitality in cryopreserved rat femora, augmented by vasculogenic growth factors. This study tests the same principal in Yucatan mini-pigs with a tibial diaphyseal defect, combining surgical angiogenesis with angiogenic gene therapy within cryopreserved orthotopically-placed allografts. Tibial diaphyseal defects were reconstructed with cryopreserved allografts and rigid internal fixation in 16 mini pigs. Half of the cranial tibial AV bundles placed within the allograft medullary canal were transfected with an adeno-associated virus containing vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) genes (AAV9.VEGF.PDGF). Bone remodeling, angiogenesis, and allograft healing were assessed. During the postoperative survival period 5 of 8 transfected animals developed cutaneous benign vascular lesions at sites remote from the operated hindlimb, causing excessive bleeding. Within the allograft, both medullary (p = 0.013) and cortical (p = 0.009) vascular volumes were higher and vessels more mature than nontransfected allografts. Bone turnover (p = 0.013), bone mineralization (p = 0.018), bone healing (p = 0.008) and graft incorporation (p = 0.006) were all significantly higher in the gene therapy group. In a large animal tibial defect model, gene therapy of implanted AV bundles improved revascularization, remodeling and healing of cryopreserved allografts used for limb reconstruction. However, benign vascular lesions causing excessive bleeding developed in 5 out of 8 pigs transfected with AAV containing genes for VEGF and PDGF. This unforeseen complication makes vasculogenic gene therapy unacceptable for clinical use.

Treatment of Dysplasia Epiphysealis Hemimelica with Autologous Chondrocyte Implantation: A Case Report.

Case: We present a case of dysplasia epiphysealis hemimelica (DEH) involving the posteromedial distal femur in a 4-year-old girl. The patient underwent lesion resection with internal fixation of the articular cartilage followed by autologous chondrocyte implantation (ACI) to restore the articular surface and epiphysis. At the 7-year follow-up, the patient had no pain or difficulty with participation in sports. Advanced imaging showed a stable articular surface with evidence of durable cartilage integration. Conclusion: DEH is a rare disease often treated by resection. In cases where the articular surface of the knee is involved, we have demonstrated that augmentation with ACI can be an effective treatment option.

EXPERIMENTAL STUDY OF BONE DENSITY IN PATIENTS WITH CONGENITAL PSEUDOARTHROSIS OF THE TIBIA BEFORE AND AFTER SURGERY.

OBJECTIVE: The aim: Determine the changes in bone density that occur in the cortical layer of the tibia in patients with CPT after surgical treatment due to radiography data. PATIENTS AND METHODS: Materials and methods: The study was performed on X-rays of the tibia of three patients with CPT, aged 5 to 7 years. X-rays were taken before surgery and 1 year after surgery. The optical density of the cortical layer of both tibia bones was determined, for which they were conditionally divided into 7 zones. RESULTS: Results: In all patients with CPT before treatment, there is significant decrease in the optical density of cortical bone tissue of the damaged tibia compared with contralateral. One year after surgery, there was an increase in the optical density of the cortical layer of both tibia of the studied patients. The increase in the density of the nonoperated tibia can be attributed to the active growth of patients. On the operated limb, the increase in the density of the cortical layer became statistically significant in all studied areas, which can be attributed not only to the growth of patients, but also to the possibility of active loading of the operated limb. CONCLUSION: Conclusions: In all patients with CPT before treatment, a statistically significant decrease in the density of cortical bone tissue of the damaged tibia was observed. As a result of the treatment there is an approximation of the bone density of the operated limb to the indicators of intact contralateral bone.

Hemimelia tibial: Presentación de un caso / Tibial Hemimelia

Introducción: La hemimelia tibial o hemimelia paraxial longitudinal tibial, es una deficiencia congénita de la tibia. Esta deficiencia de los miembros inferiores longitudinal tibial, es muy rara y su frecuencia está en el orden de 1: 1 000 000 de niños nacidos vivos. Objetivo: Presentar un caso de hemimelia tibial diagnosticado por medio del cuadro clínico y radiografías y tratado quirúrgicamente. Presentación del caso: Paciente masculino de dos horas de nacido, atendido por presentar malformación congénita a nivel de la pierna derecha que se presentaba acortada con una prominencia dura a nivel proximal y el pie con deformidad marcada en supinación, aducción y rotación interna. Se realizó examen físico exhaustivo de la extremidad afecta y se constató el acortamiento evidente de la misma. Se indicó radiografía anteroposterior y lateral de la pierna y se observó que el segmento proximal de la tibia y el peroné estaban bien, pero con implantación alta, por lo que se diagnosticó una hemimelia tibial tipo II de Jones. Luego del alta el niño recibió seguimiento por consulta de Genética y el servicio de Ortopedia donde se decidió someterlo a un primer tiempo quirúrgico a los 6 meses de edad, mediante tibialización del peroné. A los 10 meses se realizó un segundo tiempo quirúrgico para centrar el astrágalo al peroné. Conclusiones: La hemimelia tibial se considera un diagnóstico poco frecuente en nuestro medio. No existe prevención conocida. El tratamiento es complejo y altamente especializado, y en algunos casos requiere la amputación temprana del miembro afectado para adaptar al paciente al uso de prótesis(AU)

Introduction: Tibial hemimelia or tibial longitudinal paraxial hemimelia is a congenital deficiency of the tibia. This tibial longitudinal lower limb deficiency is very rare and its frequency is in the order of 1: 1,000,000 live births. Objective: To report a case of tibial hemimelia diagnosed through the clinical condition and radiographs and treated surgically. Case report: We report the case of a two-hour-old male patient, treated for a congenital malformation at the level of the right leg that was shortened with a hard prominence at the proximal level and the foot with marked deformity in supination, adduction and internal rotation. An exhaustive physical examination of the affected limb was carried out and its evident shortening was confirmed. Anteroposterior and lateral X-rays of the leg were indicated and it revealed that the proximal segment of the tibia and fibula were fine, but with high implantation, for which a Jones type II tibial hemimelia was diagnosed. After discharge, the child was followed up by the Genetics consultation and the Orthopedics service, where it was decided to undergo a first stage surgery at 6 months of age, by means of tibialization of the fibula. At 10 months, a second surgical time was performed to center the talus to the fibula. Conclusions: Tibial hemimelia is considered a rare diagnosis in our setting. There is no known prevention. Treatment is complex and highly specialized, and in some cases requires early amputation of the affected limb to adapt the patient to the use of a prosthesis(AU)

Correlation of short knee and full-length X-rays in evaluating coronal plane alignment in total knee arthroplasty.

BACKGROUND: Coronal alignment after total knee arthroplasty (TKA) would influence the implant survival. Coronal alignment could be measured on short and full-length X-rays. The goal of the current study was to assess the correlation of short and full-length X-rays to accurate prediction of the true Hip-Knee-Ankle alignment after TKA in the Iranian population. METHODS: Lateral distal femoral and medial proximal tibial angles, FTA, HKA, in 180 Iranian patients (243 knees without extra-articular deformities) were measured and compared on short and full-length standing X-rays of primary TKA pre/postoperatively. RESULTS: The correlation between the preoperative FTA-short and FTA-long, FTA-short and HKA, and FTA-long and HKA values in degrees were fair, good and good (r = 0.64) (r = 0.73), (r = 0.76), respectively. This correlation for postoperative aMPTA and mMPTA (r = 0.73), and FTA-short and HKA (r = 0.76) values were good and significant (P = 0.001). Also, assessing coronal alignment based on short and full-length measurements would result in varying pre/postoperative alignments (varus, neutral and valgus). CONCLUSION: Full length X-rays could not be replaced by short knee X-rays to asses true coronal alignment in TKA; considerable portion of our cases were missorted as varus, neutral or valgus based on the FTA versus the HKA. Intraoperative fixed 5° valgus angle cut of distal femur did not result in postoperative favorable neutral alignment in all cases. LEVEL OF EVIDENCE: IV.

Analysis of risk factors affecting union and refracture after combined surgery for congenital pseudarthrosis of the tibia: a retrospective study of 255 cases.

BACKGROUND: Congenital pseudarthrosis of the tibia (CPT) is a rare disease occurring in children. The aim of this study is to identify the factors affecting bone union and re-fracture after surgery for CPT and to provide reliable evidence for clinics. METHODS: We collected the detailed information of 255 cases with Crawford IV CPT treated by combined surgery in our hospital from 2013 to 2020. Basic characteristics were recorded. Univariate variance and logistic regression analysis were used to compare the correlations between factors and outcomes. RESULTS: 92.5% of patients achieved primary union, 7.5% of patients had non-union and 13.3% of patients had re-fracture. Logistic regression analysis showed that age at index surgery (Coef. = 0.171, 95%CI 0.015-0.327, P = 0.032), and CPT location (Coef. = - 1.337, 95%CI - 2.218-0.456, P = 0.003) had statistical differences, while no factors had significant correlation with re-fracture. Furthermore, ROC curve showed that the optimal age threshold for first surgery was 2.37 years old. CONCLUSIONS: For patients with Crawford IV CPT treated by combined surgery, the younger the age at index surgery and the closer the CPT location to the distal end, the easier to achieve bone union.