Mean Mechanical Axis Deviation Research Articles

Functional and Radiological Outcome of Simultaneous Bilateral Total Knee Replacement in a Tertiary Care Centre : A Quasi-prospective Study.

Osteoarthritis (OA) is the most frequent joint disease with a prevalence of 5313 per 100,000 persons in India. OA of the knee is a major contributor to mobility impairment, particularly among women. In these patients, total knee replacement (TKR) is widely accepted as the gold standard treatment for pain relief and restoration of function. Now, patients have the option of undergoing either a simultaneous bilateral TKR or a staged TKR. The former has shown significant advantages such as shorter rehabilitation, cost efficacy and shorter hospital stay. This study aimed to assess the functional and radiological outcome of simultaneous bilateral TKR in a tertiary care centre. 30 adult patients above the age of 55 years with severe OA knee who underwent simultaneous bilateral TKR between 2022-2023 were included in this prospective study. Preoperatively, they were assessed with radiographs including full length scannograms. Mean Anatomical Axis, Mean Mechanical Axis and Mechanical Axis Deviation (Varus) were calculated based on the scannograms by a single observer. The same observer administered the oxford knee score (OKS) preoperatively to all patients. Regular clinical and radiological follow up was done. After 1 year follow up, the same observer administered the Oxford Knee Score (OKS) to the operated knee. With a female preponderance among the study subjects (56.7%), the majority of the cases in our cohort were characterised as Grade IV Kellgren-Lawrence radiological grade of Osteoarthritis (76.66%) and were found to have tricompartmental involvement (70%). The mean anatomical axis for the right and left lower limb were 4.56±5.17 and 9.68±1.72 respectively. The mean mechanical axis deviation (Varus) for the right and left lower limb were 31.6±15.1 and 52.0±13.9 respectively. Preoperatively, mean mechanical axis for the right and left lower limb were 9.95±4.31 and 14.2 ±0.67 respectively. Postoperatively, mechanical axis was restored to near-normal values (3-5 degrees). Significant improvement in mean OKS from a preoperative value of 18.30 ± 3.46 to postoperative value of 33.50 ± 5.32 was noted at 1 year. Treatment of severe bilateral OA knee with simultaneous single staged bilateral TKR ensures good functional outcome , early mobility with minimal complications.

Transphyseal Hemiepiphysiodesis: Is it Truly Reversible?

Although numerous studies reported the efficacy of percutaneous epiphysiodesis using transphyseal screws (PETS) in correcting angular knee deformities, many surgeons refrained from using it in younger children because of a lack of objective evidence of reversibility. Our hypothesis is that PETS is both truly reversible and effective. Twenty-one patients aged 8 to 13 years (36 lower limbs LL) with coronal plane knee deformity were enrolled into this prospective case series from January 2021 to September 2023. Besides the routine monitoring of PETS efficacy, low dose CT knee of 32 treated physes was done 6 months after screw removal. In addition, lower limb length, mechanical lateral distal femur angle (mLDFA), and medial proximal tibial angle (MPTA) were recorded preoperatively and 6 to 17 months after screw removal for 24 LL to investigate physis behavior, technique reversibility, and resumption of bone growth after screw removal. The mean mechanical axis deviation (MAD) correction rate was 3.46mm/mo and 1.78mm/mo for genu valgum and genu varum patients, respectively. No physeal bony bars could be detected 6 months after screw removal for all patients. Out of 24 physis that underwent computerized radiography (CR) of the whole lower limb, 12 LL resumed their growth, 4 were stationary, while 8 were excluded due to inadequate calibration. A single physis showed rebound deformity, and another showed overcorrection in the genu valgum group. In addition to being a highly effective method of hemiepiphysiodesis, PETS was found to be reproducible, safe, and reversible when used in the juvenile and early adolescent pediatric population. IV-Prospective case series.

Hemiepiphysiodesis for Genu Valgum in Patients With Multiple Hereditary Exostoses.

Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population. All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum. A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up. Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction. Level III.

Wedgeless V-Shaped Osteotomy of the Distal Medial Femur with Locking Plate Fixation for Correction of Genu Valgum in Adolescents and Young Adults.

Genu valgum is a common disorder affecting adolescents and young adults. Treatment of this disorder requires restoration of normal mechanical axis alignment and joint orientation, for which it is important to assess whether the deformity arises from the distal femur, knee joint, or proximal tibia. Most commonly, the deformity originates from the distal femur, and various osteotomies of the distal femur have been described1-6. The presently described wedgeless V-shaped osteotomy7,8 is a good option among the various alternative procedures listed below. The anesthetized patient is placed in the supine position on a radiolucent operating table. A bolster is placed beneath the knee to relax the posterior structures. A medial longitudinal skin incision is made that extends from the level of the medial joint line to 5 cm proximal to the adductor tubercle. The vastus medialis is identified and elevated anteriorly by detaching it from its distal and posterior aspects. The leash of vessels underneath the vastus medialis is identified, and the apex of the V-shaped osteotomy is kept just proximal to it. The anterior arm of the V is kept longer than the posterior one, both of them are kept perpendicular to each other, and the apex of the V is made to point distally. The osteotomy is performed on the medial cortex with use of an oscillating saw or multiple drill holes that are then connected using a thin osteotome. Care is taken not to utilize a saw or drill on the lateral cortex. A gentle valgus thrust is applied to break the lateral cortex without periosteal disruption. The apex of the V osteotomy on the proximal fragment is trimmed, and the deformity is corrected with varus force. The osteotomy site is stabilized with use of an anatomically contoured distal medial femoral locking plate or a medial proximal tibial L-shaped buttress plate (of the contralateral side). The implant position is verified under a C-arm image intensifier. The wound is closed in layers over a suction drain in a standard manner. Various types of corrective osteotomies of the distal femur have been described in the literature, including the lateral opening wedge, medial closing wedge, dome, and spike osteotomies1-6. All of these procedures have certain limitations and shortcomings. The wedgeless V-shaped osteotomy is another described procedure that is inherently stable7,8. It is a safe procedure and yields good clinical outcomes8,9. The posterior arm of the V-shaped osteotomy is kept smaller than the anterior arm. The proximal cortical bone is allowed to dig into the cancellous bone of the wider distal metaphysis during deformity correction. Trimming the apex of proximal bone end after making the osteotomy facilitates the process. In a study of 46 patients with a mean age of 16.9 years (range, 15 years to 23 years), Gupta et al.8 reported that the mean radiographic tibiofemoral angle improved from 22.2° (range, 16° to 29°) preoperatively to 5.1° (range, 0° to 10°) postoperatively (p < 0.001). Similarly, the mean lateral distal femoral angle improved from 79.2° preoperatively to 89.1° postoperatively (p < 0.001) and the mean mechanical axis deviation improved from 19.6 mm preoperatively to 3.7 mm postoperatively (p < 0.001). A total of 44 of 46 cases had an excellent functional outcome, with the other 2 having good outcomes. None of the patients in the study had an unsatisfactory outcome. It is important to keep the whole lower limb accessible to the image intensifier intraoperatively.Identification of the leash of vessels underneath the vastus medialis is important to decide the level of the osteotomy.It is important to preserve the periosteal sleeve on the lateral aspect of the femur. CORA = center of rotation of angulationECG = electrocardiogramLDFA = lateral distal femoral angleMAD = mechanical axis deviationMPTA = medial proximal tibial angle.

Effect of ascending and descending medial open wedge high tibial osteotomy on patella height and functional outcomes-a retrospective study.

High tibial osteotomy (HTO) is a popular joint-preserving option for medial compartmental osteoarthritis. However, this is associated with alterations in the patellar height (PH) and tibial slope (TS). This study aims to compare the effect of ascending (AMHTO) and descending medial opening wedge HTO (DMHTO) on patella height, posterior tibial slopeand functional outcomes. A retrospective study was conducted between February 2018 and July 2021. Patients with medial compartment osteoarthritis, varus alignment, and complete pre- and postoperative lateral and full-length anteroposterior radiographs were included. Pre- and postoperative radiological measurements include the Caton-Deschamps index (CDI), the mechanical axis deviation (MAD), and the posterior tibial slope. The functional outcomes were measured using the Oxford Knee Score (OKS), Lysholm Knee Score (LKS), and Tegner Activity Scale (TAS). The osteotomy union was checked with serial X-rays every 6weeks till a satisfactory union was achieved. Fifty-eight patients were included in the study. Thirty-four (58%) patients received AMHTO, and 24 (42%) received DMHTO. There was no baseline difference in the demographic variables or functional scores between the two groups. The preoperative mean MAD of - 9.65° ± 3.67° was corrected significantly to + 0.08 ± 2.80° (varus -, valgus + , P = 0.034). A significant difference in preoperative and postoperative CDI of 0.93 ± 0.45 and 0.83 ± 0.27, respectively, was noted (P = 0.023). In the AMHTO group, a statistically significant decrease in PH from preoperative 1.03 ± 0.77 to 0.84 ± 0.12 was noted (P = 0.003). There was a significant improvement in functional outcomes between baseline and 9-month follow-up in both groups. There was no significant difference between the functional outcomes of the two groups at 9-month follow-up. The study confirmed our hypothesis that descending HTO caused less alteration in the patella height compared to ascending HTO. There is no significant difference in the functional outcomes between the groups. However, in patients with PFOA, and when attempting higher degree of correction through AMHTO, the possibility of worsening of symptoms due to change in PH must be considered.

Isolating factors for the prediction of rebound after guided growth with tension band plating for the valgus deformity of the knee.

The conditions leading to growth rebound after hemiepiphysiodesis are still poorly understood. This article analyzes the radiographical outcomes after guided growth with tension band plating, using plates in idiopathic genu valgum patients and attempts to generate a predictive model of growth rebound. Patients with idiopathic genu valgum deformity who received tension band plating were selected for evaluation. We only analyzed coronal plane deformities. Only patients with a long-standing X-ray before tension band plating surgery, a long-standing X-ray at tension band plating removal, and a long-standing X-ray at the latest follow-up after tension band plating removal were considered for this study. The change of mechanical axis deviation between the tension band plating removal and the last follow-up was evaluated for rebound, and ordinal logistic regression was performed to determine the relevant variables for predictive modeling rebound growth. Overall, 100 patients (189 legs) were analyzed. The mean mechanical axis deviation at tension band plating removal was 8.4 mm in varus direction, and the mean mechanical axis deviation at the last follow-up was -3.4 mm (p ≤ 0.001). However, 111 legs (59%) showed rebound growth, 57 (30%) stayed stable, and 21 (11%) showed a continuous correction. Six significant factors significantly influencing rebound were isolated which are clinically relevant: sex, age, baseline mechanical axis deviation, mechanical lateral distal femoral angle, and mechanical medial proximal tibial angle, and mechanical axis deviation correction rate. Mechanical axis deviation correction rate had the highest odds ratios. The machine learning classification model for predicting rebound growth built from the study data showed a misclassification rate of 39%. There was a high rate of rebound growth in this cohort, especially for patients at a young age at implantation. The highest risk factors for rebound growth were male sex, and high correction rates, such as found during peak growth spurt. The proposed classification model needs more data to improve its predictive power before it can be used in clinics. Level III.

Growth Modulation by Tension Band Plate in Achondroplasia With Varus Knee Deformity: Comparison of Gait Analysis Measurements.

Limited evidence exists concerning growth modulation by tension band plate (TBP) to correct varus deformity in patients with achondroplasia with limited growth due to FGFR3 gene mutation. We evaluated the efficacy of TBP in children with achondroplasia with genu varum and reported the static radiographic and dynamic motion data to determine parameters that impact the rate of deformity correction. Patients with achondroplasia with genu varum who underwent TBP surgery for growth modulation were studied. Those with at least 1 year of follow-up with TBP were included. Radiographic parameters were measured. Growth velocity of femoral/tibial length was calculated separately. Patients were deemed successful or unsuccessful. Spearman correlation analysis and Student t test were used to describe statistical results. Twenty-two patients (41 limbs; 12 girls) fulfilled our criteria. Mean age at TBP surgery was 7.6±2.4 years. Thirty-six femoral TBP and 41 tibial TBP were in place for 24.5±9.7 months. Mean mechanical axis deviation, mechanical lateral distal femoral angle, and medial proximal tibial angle preoperatively were 30.1±7.6mm, 97.2±6.4, and 80.3±4.3 degrees, and 11±15.6mm, 87.4±5.9, and 84.7±5.3 degrees at last follow-up ( P <0.001). Fifteen limbs were successfully straightened; 4 limbs were in more varus than the initial deformity. Twenty-four limbs with TBP were still undergoing correction. In successful limbs, mean age at surgery was 6.5±1.7 years and duration of TBP was 29.9±7.8 months. In 4 unsuccessful limbs, mean age at surgery was 11.7±1.2 years. Analysis in the gait laboratory included physical examination with the measurement of knee varus and kinematic varus based on a posterior view static standing photograph. Photographic measurement of varus was higher than the radiographic measurement. Growth modulation by TBP surgery is a reliable and simple technique to correct genu varum in achondroplasia. An early age at TBP implementation (mean: 6.5y) is crucial to successfully correct the varus knee deformity. Furthermore, we recommend early and regular surveillance of achondroplasia for progressive varus knee deformity. Level IV-cohort study.

Natural behaviours after guided growth for idiopathic genu valgum correction: comparison between percutaneous transphyseal screw and tension-band plate

BackgroundPercutaneous epiphysiodesis using a transphyseal screw (PETS) or tension-band plating (TBP) has shown favourable correction results; however, the physeal behaviours in terms of rebound, stable correction, or overcorrection after guided growth have not been completely understood. In patients with idiopathic genu valgum, we therefore asked: (1) How is the correction maintained after implant removal of guided growth? (2) Is there any difference in the natural behaviours after PETS or TBP removal at the femur and tibia?MethodsWe retrospectively reviewed 73 skeletally immature limbs with idiopathic genu valgum treated with PETS or TBP. PETS was performed in 23 distal femurs and 13 proximal tibias, and TBP was performed in 27 distal femurs and ten proximal tibias. Mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle were measured at pre-correction, implant removal, and final follow-up. Changes of ≤ 3° in mechanical angles after implant removal were considered stable. Comparisons between the implant, anatomical site, and existence of rebound were performed.ResultsThe mean MAD improved from − 18.8 mm to 11.3 mm at implant removal and decreased to -0.2 mm at the final follow-up. At the final follow-up, 39 limbs (53.4%) remained stable and only 12 (16.4%) were overcorrected. However, 22 limbs (30.1%) showed rebound. TBP was more common, and the correction period was longer in the rebound group (p < 0.001 and 0.013, respectively). In femurs treated with PETS, the mean mLDFA increased from 86.9° at implant removal to 88.4° at the final follow-up (p = 0.031), demonstrating overcorrection. However, a significant rebound from 89.7° to 87.1° was noted at the femur in the TBP group (p < 0.001). The correction of the proximal tibia did not change after implant removal.ConclusionThe rebound was more common than overcorrection after guided growth; however, approximately half the cases demonstrated stable correction. The overcorrection occurred after PETS in the distal femur, while cases with TBP had a higher probability of rebound. The proximal tibia was stable after implant removal. The subsequent physeal behaviours after each implant removal should be considered in the guided growth.

Results of Wedgeless Distal Femoral Osteotomy for the Treatment of Genu Valgus Deformity.

Coronal plane knee deformities are common disorders affecting adolescents. Valgus deformities (tibiofemoral angle (TFA) > 12-15 degrees and intermalleolar distance (IMD) > 10 cm) often require corrective osteotomy and a wedgeless "V" distal femoral osteotomy is a good treatment option for such deformities. Thirty adolescent patients (13-17 years) with valgus deformitieswere included. Patients with severe collateral ligament instability, subluxation, and sagittal plane deformity > 15 degrees or genu valgum due to tibial deformity were excluded. Preoperativeclinical(Bostman's knee score, IMD, and knee-flexion test) and radiological evaluations weredone. The surgery (wedgeless distal femoral V osteotomy) was performedand stabilized with two Kirschner wires (K-wires). Postoperative clinical and radiological parameters were recorded including complications. The preoperative TFA was 20.23 ± 3.63 degrees, which reduced to 5.5 ± 0.73 at six months postoperatively. The preoperative IMD was 12.45 ± 2.2 cm, which reduced to 1.63 ± 0.32 cm at six months. The mean mechanical axis deviation (MAD) and lateral distal femoral angle (LDFA)were recorded as 2.8 ± 0.39 and 87.7 ± 0.83, respectively, and the differences were statistically significant from preoperative values. The Bostman score was 26.2 ± 1.79 at three months and 29.47 ± 0.9 at six months. The complications included infection in two patients, a hypertrophic scar in one patient, and common peroneal neuropraxia in one patient. Wedgeless distal femoral osteotomywith K-wire fixation is a viable option for correction of genu valgus deformity with potential advantages of minimal blood loss, no leg length discrepancy, non-rigid fixation, and early union as compared to other treatment options.

Acute correction of distal femoral deformities by retrograde femoral nail using preoperative planning.

This study presents the technique and results of acute correction of distal femoral deformities using retrograde femoral nailing based on preoperative planning without using a fixator. Twenty-eight patients (34 limbs: 22 left-sided, 12 right-sided, mean age = 36years) undergoing distal femoral deformity correction with retrograde femoral nailing between 2013 and 2020 were examined retrospectively. The osteotomy line, block screw location and number were identified by detailed preoperative planning. Osteotomy was performed using the percutaneous multiple drill method, and the retrograde femoral nail was placed. The average follow-up period was 62.7months (range: 13-84months). Postoperatively, the mean mechanical axis deviation was corrected to 6.8mm (range: 0-8mm) and the mean mechanical lateral distal femoral angle to 87.42° (range: 84-90°). The Association for the Study an Application of the Method of Ilizarov (ASAMI) score was excellent for all patients. None of the patients had fracture, infection, implant failure, or non-union. Distal femoral deformities can be corrected acutely, without applying external fixators, with good preoperative planning and using the retrograde femoral nail. This technique is safe and effective, with a low complication rate.

Persistent Lower Limb Deformities Despite Amelioration of Rickets in X-Linked Hypophosphatemia (XLH) - A Prospective Observational Study.

BackgroundGait deviations, lower limb pain and joint stiffness represent key symptoms in patients with X-linked hypophosphatemia (XLH, OMIM 307800), a rare disorder of mineral homeostasis. While the pathomechanism for rickets is well understood, the direct role of PHEX (Phosphate-regulating neutral endopeptidase) deficiency in non-rachitic features including complex deformities, skull and dental affections remains unclear. FGF23-inhibiting antibody treatment can normalize serum phosphate levels and to improve rickets in XLH patients. However, linear growth remains impaired and effects on lower limb deformity and gait are insufficiently studied.AimsTo characterize and evaluate the course of lower limb deformity in a case series of pediatric XLH patients receiving Burosumab therapy.MethodsComparative assessment of planar radiographs, gait analysis, biochemical and clinical features of pediatric patients before and ≥12 months after initiation of FGF23-inhibiting was performed prospectively. Lower limb maltorsion was quantified by torsional MRI and gait analysis. Standardized deformity analysis of lower limb anteroposterior radiographs was conducted.ResultsSeven patients (age 9.0 +/-3.6 years) were eligible for this study. All patients received conventional treatment before onset of antibody treatment. Maltorsion of the femur was observed in 8/14 legs using torsional MRI (mean antetorsion 8.79°). Maltorsion of the tibia was observed in 9/14 legs (mean external torsion 2.8°). Gait analysis confirmed MRI findings with femoral external malrotation prior to and one year after onset of Burosumab therapy. Internal foot progression (intoeing gait) remained pathological in all cases (mean 2.2°). Knee rotation was pathologically internal 10/14 legs. Mean mechanical axis deviation (MAD) of 16.1mm prior to Burosumab changed in average by 3.9mm. Three children underwent guided growth procedures within the observation period. Mild postprocedural rebound of frontal axis deviation was observed under Burosumab treatment in one patient.ConclusionsThis is the first study to investigate lower limb deformity parameters quantitatively in children with XLH receiving Burosumab. One year of Burosumab therapy was associated with persistent maltorsion and frontal axis deviation (varus/valgus) despite improved rickets in this small, prospective uncontrolled study.

Lower Limb Alignment in Indian Children: A Radiographic Analysis of Coronal Plane Parameters

Indian children are known to have variations in the tibiofemoral angle as compared to children of other ethnicities. There is no study describing radiographic angles in coronal plane in Indian children. Our aim was to evaluate coronal plane alignment in Indian children. Database of radiographs between January 2011 and December 2019 was searched. Full-length standing radiographs of patients younger than 16years with unilateral congenital or post-traumatic or post-infective deformity were included. The radiographs were measured for mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), tibiofemoral angle (TFA), hip-knee-ankle (HKA) angle, lateral distal tibial angle, mechanical axis deviation (MAD), and mechanical lateral proximal femoral angle. Analysis of 221 lower limbs of 177 children is presented. There were 103 (58.2%) boys and 74 (41.8%) girls. Mean age was 8years, 6months (range: 2years, 1month to 15years, 11months). The mean mLDFA remained constant between 87° and 88° after the age of 5years. The mean MPTA remained around 88° after 8years of age. The mean MAD remained within 4mm of the midpoint of the knee after the age of 8years. The adult value of TFA was achieved after 8years of age. The mLDFA, MPTA, and mLPFA are significant predictors of change in the TFA. The development of tibiofemoral angle in Indian children is slightly different than children of other ethnicities. We recommend using age-specific values for Indian children younger than 8years of age.

Multiplanar correction of proximal tibial recurvatum deformity with tibial osteotomy and computer assisted fixator

BackgroundSeveral treatment modalities including open wedge osteotomies and Ilizarov reconstruction have been described for treatment of Proximal tibial recurvatum (PTR). However, the literature lacks information regarding the multiplanar correction of PTR using the computer assisted hexapod external fixator. The aim of the study is to present the results of PTR treatment with a computer assisted fixator systems. MethodsThere were three female and three male patients (10 lower extremities) with a mean age of 20.6 years (7.3 to 25.2y) in the study group. The angle of genu recurvatum (aGR), the tibial plateau tilt angle (aTP), the mechanical posterior proximal tibial angle (mPPTA) and sagittal mechanical axis deviation (MADs) was measured for the sagittal plane assessment. ResultsPreoperative sagittal assessment showed that the mean aGR was 28.9°±6.8°, mean aTP was 64.5°±10.2° and mean mPPTA was mPPTA was 114.1° ±10.3°. At the final follow-up there was a significant correction (p < 0.05 for aGR, aTP and mPPTA). Mean MADs was improved from 66.1 ± 14.2 mm to 16.6 ± 5.1 mm (p:0.005). Mean A:B ratio was 0.92 ± 0.13 preoperatively and 0.89 ± 0.14 postoperatively (p:0.37). Nine out of 10 knees had valgus deformity and mean preoperative tibiofemoral anatomic angle (TFA) was improved from 10.8°±3.7° valgus to 6.5°±1.7° valgus. ConclusionThe treatment of PTR deformity with a computer-assisted hexapod external fixator is safe and effective. It provides multiplanar correction of the deformity with a high precision and the patellar alignment remains stable during the correction.

Acute correction of severe complex adolescent late-onset tibia vara by minimally invasive osteotomy and simple circular fixation: a case series with 2-year minimum follow-up

BackgroundDespite multiple published reviews, the optimum method of correction and stabilisation of Blount’s disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. Weighing up the pros and cons and to establish if this method would be the method of choice in similar severe cases especially in a context of limited resources.MethodsThis study was conducted between November 2016 and July 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32 tibiae) who had correction of severe late-onset tibia vara by proximal tibial osteotomy and Ilizarov external fixator. The mean age at the time of the operation was 16.6 (± 2.7) years (range 13–22).ResultsThe mean proximal tibial angle was 65.7° (± 7.8) preoperatively and 89.8° (± 1.7) postoperatively (p < 0.001). The mean mechanical axis deviation improved from 56.2 (± 8.3) preoperatively to 2.8 (± 1.6) mm postoperatively (p < 0.001). The mean femoral-tibial shaft angle was changed from –34.3° (± 6.7) preoperatively to 5.7° (± 2.8) after correction, with degree of correction ranging from 25° to 45°. Complications included overcorrection (three cases 9%) and pin tract infection (eight cases 25%). The mean Hospital for Special Surgery knee scoring system (HSS) improved from 51.03 (± 11.24) preoperatively to 94.2 (± 6.8) postoperatively (p < 0.001). The mean length of follow up period 33.22 (± 6.77) months, (rang: 25–46 months). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity.ConclusionThis simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities.

Simultaneous multisegmental and multifocal corrections of complex lower limb deformities with a hexapod external fixator

IntroductionExternal fixators are a part of the therapeutic arsenal used in the correction of complex pediatric lower limb deformities. These long iterative procedures, which are commonly performed over several months, strongly impact the lives of these children and their families. To reduce these drawbacks, we perform, whenever possible, a simultaneous multisegmental and/or multifocal correction of these deformities. HypothesisSimultaneous multilevel correction of complex pediatric deformities using external fixators does not result in more complications than sequential corrections. Materials and methodsSixteen patients were treated with this hexapod external fixator correction procedure. The mean age was 13.9 years. The corrections involved 12 femurs and 20 tibias, representing 53 osteotomies on 23 limbs. The quality of the correction was assessed by measuring the mechanical axis deviation (MAD), residual limb length discrepancy (RLLD) and a new, specifically defined, criterion called the “angular healing index” (AHI). Complications were assessed according to Lascombes’ classification. ResultsThe mean MAD went from 30 to 13.5 mm (P<.05) and the mean RLLD from 33.2 to 6.9 mm (P<.05). The mean AHI was 74.1 days/cm (16.7 to 319). The overall complication rate was 13/23 operated limbs or 56.5% (4.3% grade 1, 43.3% grade 2, 9.3% grade 3, and no grade 4). DiscussionOne-stage multilevel corrections of complex pediatric lower limb deformities represent a difficult technical challenge, and any reduction in treatment time must not adversely impact the quality of the results. The rate and severity of complications compared to monofocal/segmental procedures were no higher than that reported in the literature. This study demonstrated the feasibility of multisegmental and multifocal corrections, which reduced the total treatment duration compared to successive corrections, without adversely affecting the result or increasing the complication rate. Level of evidenceIV; retrospective study.

Role of hemi-epiphysiodesis using 8-plate system in the correction of coronal plane deformities around the knee

Introduction: Angular deformities around the knee in children is a common finding, these deformities are from diverse group of etiologies. Most of these deformities are physiological in nature corresponding to the changes in the alignment of tibio-femoral angle from birth to adolescence. Angular deformities can also be developed due to pathological causes like skeletal dysplasias, metabolic bone disorders, Blount’s disease and trauma. Osteotomies were the mainstay of treatment for correcting deformities in both adults and children been replaced by Hemiepiphysiodesis using 8 plates having less complication rate. Materials and Methods: A total of 49 knees (35 genu valgum, 14 genu varum) of 30 patients were studied. 8 -plates were used for correction of coronal plane deformities around the knee. All cases were followed for minimum period of 12 months. Preoperative clinical and radiological measurements were compared to post-operative measurements. Results: There was statistically significant improvement in clinical and radiological outcome measures. In genu valgum group preoperative mean Tibio-femoral angle (TFA) improved from 24.16 to 8.36. Mean Mechanical axis deviation (MAD) improved from 4.26 to 1.09. Rate of correction of TFA is 1.1/month, rate of correction of MAD is 0.22/month. In genu varum group preoperative mean TFA improved from 34.58 to 21.47. Mean MAD improved from 4.92 to 0.63. Rate of correction of TFA is 0.77/ month, rate of correction of MAD is 0.12/month. Conclusion: Hemi-epiphysiodesis using 8-plate systemin the correction of coronal plane deformities around the knee is a safe and effective procedure. Keywords: Hemiepiphysiodesis, Guided growth modulation, Genu varum, Genu valgum.

Ipsilateral Osteochondritis Dissecans-like Distal Femoral Lesions in Children with Blount Disease: Prevalence and Associated Findings.

ABSTRACTPurposeOur goal was to assess the prevalence of ipsilateral distal femoral osteochondritis dissecans (OCD)-like lesions in children with Blount disease, including factors associated with this finding.Materials and methodsCharacteristics of patients with an OCD-like lesion on an imaging study [(X-ray and/or magnetic resonance imaging (MRI)] were compared with those without such a finding.ResultsOver a 12-year period, 6/63 (10%) skeletally immature patients (9/87 limbs) with Blount disease had an OCD-like lesion visible on plain radiographs. Based on available MRI, 7/37 (19%) patients or 10/53 (19%) limbs had an OCD-like distal femoral lesion. All lesions were noted in the posterior third of the weight-bearing portion of the medial femoral condyle with intact overlying articular cartilage. All patients with OCD-like lesions were followed for an average of 1.9 years (range: 1–2.6 years), and complete radiographic resolution of lesion was noted in 7/9 limbs (78%). There was no association of the presence of OCD-like lesion with early- vs late-onset disease, gender, age at imaging, laterality, magnitude of deformity [mean mechanical axis deviation (MAD) 63.3 vs 71.9 mm], mean mechanical lateral distal femoral angle (mLDFA; 91.3 vs 89.7°), and mean medial proximal tibial angle (MPTA; 71.7 vs 71.8°). Children with an OCD-like lesion tended to have a lower mean body mass index (BMI; 21 vs 36, p = 0.003).ConclusionThe overall prevalence of OCD-like lesions in the medial femoral condyle in children with Blount disease lesions is 10% using plain radiographs and at least 19% on MRI. Based on the numbers available, we were unable to demonstrate any associations between the presence of such lesions and the patient’s age, gender, or magnitude of varus deformity. Further research is needed to fully ascertain the aetiology and natural history of these benign appearing osteochondral imaging findings in children with Blount disease. Our current data support that these lesions do resolve with time and that no surgical intervention targeted at the femoral OCD-like lesion is warranted.Level of evidenceDiagnostic study Level III.How to cite this articleEdobor-Osula F, Wenokor C, Bloom T, et al. Ipsilateral Osteochondritis Dissecans-like Distal Femoral Lesions in Children with Blount Disease: Prevalence and Associated Findings. Strategies Trauma Limb Reconstr 2019;14(3):121–125.

Correction of Genu Valgum in Patients With Congenital Fibular Deficiency.

Patients with congenital fibular deficiency often develop genu valgum secondary to lateral femoral condylar hypoplasia. Guided growth strategies are often performed to correct limb alignment when adequate skeletal growth remains. A retrospective review of patients with postaxial hypoplasia of the lower extremity managed with an amputation strategy and who had a guided growth procedure for coronal plane limb malalignment during their course of treatment was performed. Clinical and radiographic data, including measures of coronal plane deformity and alignment, type of amputation, subsequent operative procedures, and complications were recorded. Seventeen patients (20 extremities) met study inclusion criteria (mean follow-up 8.8 y). Foot ablation and hemiepiphysiodesis for valgus deformity of the knee was performed in all extremities. The average age at the time of initial hemiepiphysiodesis was 11.2 years at an average of 8.8 years from the initial amputation procedure. The mean preoperative mechanical axis deviation was 26.5 mm, which was corrected to a mean mechanical axis deviation of 7.0 mm. Fifteen (75%) of the extremities had correction of the deformity to neutral alignment after the initial procedure. Lack of correction occurred in 3 extremities, and overcorrection occurred in 2 extremities. Additional procedures were required in 5 extremities for rebound valgus deformity after hardware removal. In patients with postaxial hypoplasia, regular monitoring of the residual limb for growth-related changes must occur to ensure optimal function and prosthetic fit. Timing of the guided growth procedure is critical, as younger patients may be more likely to experience rebound deformity. Families and patients should be made aware that growth might be unpredictable in this population with risks of both overcorrection and undercorrection. Level IV-case series.

Three-dimensional assessment of lower limb alignment: Reference values and sex-related differences

BackgroundThree-dimensional (3D) preoperative planning and assisted surgery is increasingly popular in deformity surgery and arthroplasty. Reference ranges for 3D lower limb alignment are needed as a prerequisite for standardized analysis of alignment and preoperative planning in 3D, but are not yet established. MethodsOn 60 3D bone models of the lower limbs based on computed tomography data, fifteen parameters per leg were assessed by standardized validated 3D analysis. Distribution parameters and differences between sexes were evaluated. Reference values were generated by adding/subtracting one standard deviation from the mean. ResultsWomen had a significantly lower mean mechanical lateral distal femoral angle compared with men (86.4 ± 2.1° vs. 87.8 ± 2.0°; P < .05) and significantly lower mean joint line convergence angle (−2.5 ± 1.4° vs. -1.3 ± 1.2; P < .01), but higher mean hip knee ankle angle (178.9 ± 1.9° vs. 177.8 ± 2.3°; P < .05) and mean femoral torsion (18.2 ± 9.5° vs. 13.2 ± 6.4°; P < .05), resulting in a tendency towards valgus alignment and vice versa for men. Differences in mean medial proximal tibial angle were not significant. The mean mechanical axis deviation from the tibial knee joint center was 6.9 ± 7.3 mm medial and 1.4 ± 16.1 mm ventral without significant differences between sexes. ConclusionsWe describe total and sex-related reference ranges for all alignment relevant axes and joint angles of the lower limb. There are sex-related differences in certain alignment parameters, which should be considered in analysis and surgical planning.

Rebound of Frontal Plane Malalignment After Tension Band Plating.

Despite the popularity of tension band plating (TBP) current literature lacks clinical data concerning recurrence ("rebound") of frontal plane malalignment. This study investigated the rebound phenomenon after TBP in idiopathic genu varum/valgum deformities. We analyzed factors that may contribute to the development of rebound after removal of TBP. Patients who had correction of idiopathic valgus or varus deformities by TBP at the distal femoral and/or proximal tibial growth plate were selected from a prospective consecutive database. Only patients who had plates removed for at least 1 year and had a long standing radiograph of the lower limbs before plate removal were included. Patients who had presumably not yet reached skeletal maturity (age under 14 y for girls and under 16 y for boys) were excluded. The change of the mechanical axis from plate removal to follow-up after skeletal maturity was evaluated and a statistical analysis was performed. Twenty-nine patients (64 extremities) were eligible. The mean follow-up was 39.1 months (range, 12.3 to 67.3 mo). The mean mechanical axis deviation (MAD) was +0.8 mm (range, -26 to +22 mm) after plate removal and -2.4 mm (range, -29 to +27 mm) at follow-up, accounting for a significant change of MAD (P=0.046). We observed a mean, relative recurrence of frontal plate malalignment into valgus direction of -3.2 mm (range, -48 to +23 mm). Twenty extremities (31%) showed <3 mm of MAD change; 27 extremities (42%) showed >3 mm of MAD change into valgus, and 17 extremities (27%) >3 mm of MAD change into varus direction. Patients with <3 mm MAD change had only 0.8 years, and those >3 mm a mean of 2.0 years of remaining growth until skeletal maturity. Each additional m/kg of body mass index increased the risk of valgus recurrence by 12.1%. The 3 genua vara patients revealed to have an even higher rate of malalignment recurrence (4 of 6 limbs) at final follow-up. Given our strict criteria, there is a high rate of radiologic recurrence of frontal plane malalignment after TBP. Children who are more than 1 year before skeletal maturity at TBP removal, and those with increased body mass index are at higher risk for rebound growth. Level IV-consecutive therapeutic case series.