Alkaline phosphatase in pediatric patients with genu varum caused by vitamin D-deficient rickets.

An elevated serum alkaline phosphatase (ALP) level is one of the markers for the presence of rickets in children, but it is also associated with bone formation. However, its role in diagnosing genu varum in pediatric patients with vitamin D-deficient rickets is still unknown. To clarify the role of the serum ALP level in assessing the severity of genu varum, we retrospectively investigated this issue statistically using data on rickets such as serum intact parathyroid hormone (iPTH), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, ALP, the level of creatinine as the percentage of the median according to age (%Cr), and the metaphyseal diaphyseal angle (MDA) in the lower extremities as an index of the severity of genu varum. A multiple regression analysis revealed that log ALP and %Cr values were negatively associated with MDA values. The former association was also confirmed by a linear mixed model, while iPTH was positively associated with MDA by path model analysis. To elucidate the association of ALP with MDA in the presence of iPTH, we investigated three-dimensional figures by neural network analysis. This indicated the presence of a biphasic association of ALP with MDA: the first phase increases while the second decreases MDA. The latter phenomenon is considered to be associated with the increase in bone formation due to the mechanical stress loaded on the lower extremities. These findings are important and informative for pediatricians to understand the significance of the serum ALP level in pediatric patients with genu varum caused by vitamin D deficiency.

Focal inlay resurfacing for full-thickness chondral defects of the femoral medial condyle may delay the progression to varus deformity.

INTRODUCTION: Full-thickness chondral defects at the knee joint predispose to the beginning of a degenerative process which final consequence is the compartment collapse and finally the deviation to varus, because the cartilage of the medial femoral condyle is the most frequently affected area. Likewise, people with these chondral defects are more likely to develop tricompartmental osteoarthritis, reason why early surgical management should be the treatment of choice. The aim of this study was to compare the pre- and post-operative lower limb alignment (mechanical axis), in cases of full-thickness chondral defects of the femoral medial condyle that have been managed by means of a prosthetic focal inlay resurfacing, at a minimum follow-up of five years. METHODS: A retrospective study of patients treated for chondral defects in the medial femoral condyle was performed. The inclusion criteria were patients who had undergone a focal inlay resurfacing and minimum follow-up of 5 years. Patients that required a concomitant valguizing tibial osteotomy were finally excluded. The follow-up analysis was performed by means of radiological examinations performed prior to surgery and at the last follow-up visit. The mean limb mechanical axis of the operated knees was calculated both pre- and post-operatively, and comparisons between these two settings were performed. RESULTS: Ten patients were included: eight men and two women. The mean age at the time of surgery was 55 (40-65) years. The mean follow-up was 9 years (range 5-15). The mean limb mechanical axis was 1.33 ± 4.16 in the pre-operative setting and 2.40 ± 5.50 in the post-operative setting (p = 0.441). CONCLUSION: In the setting of small to moderate size, unique femoral medial condyle full-thickness chondral lesions, filling the defect with an inlay prosthetic resurfacing may protect against the progression to varus deformity. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.

Distal Femoral Physeal Bar Resection Combined With Guided Growth for the Treatment of Angular Limb Deformity Associated With Growth Arrest: A Preliminary Report.

PURPOSE: Distal femoral growth arrest can result in progressive deformities and functional disability. The treatment is challenging given the significant growth potential of the distal femoral physis. This study addresses the short-term outcomes after distal femoral physeal bar resection combined with guided growth for the treatment of angular limb deformity. METHODS: We conducted a retrospective analysis of patients treated with distal femoral physeal bar resection, fat graft interposition, and growth modulation with a tension-band plate. Data recorded included patient demographics, growth arrest cause, physeal bar size, time-to-surgery, details of the operative procedure, and complications. The mechanical axis zones, tibiofemoral angle, and the anatomic lateral distal femoral angle were assessed on 51-inch anteroposterior standing radiographs. RESULTS: Five patients (3 male individuals) with valgus (n=4) and varus deformities (n=1) due to physeal arrests of the distal femur were analyzed. The cause of the physeal arrest was trauma (n=3) and infection (n=2). The average age at the time of surgery was 6.6 years (range: 2 to 11 y). Average size of the physeal bar was 413.4 mm, which represented 16.8% of the total distal femoral physis (range: 12% to 26%). Four of the 5 patients had a total correction of the deformity in 14.3 months (range: 9 to 22 mo). One patient required correction by osteotomy and external fixation. Postoperatively, 1 patient presented no improvement, and 4 had restoration of the longitudinal bone growth and alignment. Two patients had rebound valgus: one is being observed and another has undergone a repeat guided growth procedure. CONCLUSIONS: Distal femoral physeal bar resection combined with tension-band hemiepiphysiodesis provides a viable option for the correction of angular deformities associated with physeal arrest. Longer follow-up is required to evaluate future growth of the distal femoral physis after this combined procedure. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Genu varum deformity due to premature epiphyseal closure after treatment with isotretinoin for neuroblastoma: A case report.

Isotretinoin, a vitamin A derivative, is known to induce premature epiphyseal closure. We report the case of a 9-year-old boy with neuroblastoma who demonstrated premature epiphyseal closure after 1 year of isotretinoin treatment (72.3 mg/m2/day). A bone bridge developed on the bilateral proximal tibial growth plate resulting in genu varum. We performed hemiepiphysiodesis on the bilateral proximal tibia in anticipation of the spontaneous resolution of the bone bridge. Genu varum on the left side was corrected with the resolution of bone bridge. For the remaining bone bridge on the right side, arthroscopy-assisted physeal bar resection was performed, and genu varum on the right lower extremity was also corrected. A regular review of the alignment of the upper and lower limbs is necessary to provide timely intervention in patients using isotretinoin, considering the possibility of premature epiphyseal closure.

Growth Modulation for Knee Coronal Plane Deformities in Children With Nutritional Rickets: A Prospective Series With Treatment Algorithm.

To report prospectively the radioclinical outcome of guided growth surgery for coronal plane deformities around the knee in young children with nutritional rickets on the intermediate term, to assess the responsiveness of torsional deformities of the tibias to guided growth regarding function and objective clinical parameters, and to propose a treatment algorithm. Methods: Fifty children (male:female, 27:23) with knee coronal plane deformities (knees:physes, 86:99), (varum:valgum, 51:35) secondary to nutritional rickets were subjected to femoral and/or tibial temporary hemiepiphysiodesis using a two-hole 8-plate. The mean age at implantation was 3.8 ± 1.5 years (range 2.5 to 5). The mean follow-up was 2.8 years (range 2 to 4). All children received a standing full-length AP radiographs of both lower limbs in neutral rotation to measure the mechanical axis deviation, tibiofemoral angle, and joint orientation angles. Tibial torsion was objectively assessed by measuring the bimalleolar axis. Results: The radiologic measurements, tibiofemoral angle, mechanical axis deviation, mechanical lateral distal femoral angle, medial proximal tibial angle, and Hilgenreiner-epiphyseal angle, showed a highly statistically significant improvement (P ≤ 0.001). Radiographic outcomes correlated with their clinical counterparts. The mean duration of correction of the mechanical axis was 10.8 ± 2.4 months (7 to 21). The mean follow-up for rebound of the deformity was 1.5 years (range 1 to 3). Conclusion: The radioclinical outcome is rewarding with a tolerable complication profile. The mechanical complications were mostly related to lengthy implant retainment encountered in severe deformities. Internal tibial torsion seems profoundly responsive to correction of coronal plane deformity. And, derotation osteotomies are rarely justified. Our proposed algorithm may be used as a decision-taking guide for achieving the desired growth modulation in a more efficient manner.

Physiologic Leg Bowing is not a Physiologic Condition but Instead is Associated with Vitamin D Disorders in Toddlers.

When children around 2-year-old show leg bowing without lower-limb radiographic abnormalities for rickets, the leg bowing is classified as "physiologic" genu varum without conducting a blood test. However, it has recently been suggested that toddlers who are diagnosed with physiologic genu varum may in fact have some form of bone metabolic disorder. In this 1:2 case-control study, blood samples were obtained from 33 toddlers with genu varum without radiographic abnormalities for rickets and 66 age- and gender-matched healthy children. Serum alkaline phosphatase (sALP), intact parathyroid hormone (siPTH), 25-hydroxy vitamin D [s25(OH)D], calcium (sCa), and inorganic phosphate (sP) were measured. s25(OH)D of the subjects with genu varum (24.8 ng/ml) were significantly lower than those of the control (33.6 ng/ml) (p < 0.001). The frequency of vitamin D insufficiency/deficiency (< 20 ng/ml) of the subjects with genu varum (39%) was significantly higher than that in the control (14%) (p = 0.004) (odds ratio by vitamin D insufficiency/deficiency: 4.1 [1.5-11.1, p = 0.004]). sCa in subjects with genu varum (10.2 ng/ml) were significantly higher than in control (9.8 ng/ml) (p < 0.001), as were sALP (1057 IU/l) and siPTH (28.4 pg/ml) (740 IU/l and 8.8 pg/ml in control, respectively; p < 0.001). siPTH levels were associated with s25(OH)D levels in subjects with genu varum (r = - 0.57, p < 0.001), while no association was observed in the control (r = 0.11, p = 0.36). Genu varum without radiographic abnormalities of rickets was associated with both vitamin D and bone-metabolic disorders in toddlers, indicating that physiologic genu varum is not a physiologic condition in toddlers.

Results through skeletal maturity of planned fibular nonunion for the treatment of genu varum in achondroplasia: An observational retrospective study.

Current surgical options for treating genu varum in achondroplasia include tibial and fibular osteotomy and growth modulation using plates and screws. However, a single surgeon consistently treated genu varum using a planned fibular nonunion (PFN). The purpose of this study is to describe his surgical technique and report radiographic and clinical outcomes for the cohort studied.This is an observational retrospective review. The cohort studied included patients with achondroplasia who had PFN surgery for the treatment of genu varum at a young age (<13 years) and was followed through to skeletal maturity. The surgery included meticulous closure of the periosteum over the remaining fibula. The surgery was considered a success if the patient did not require subsequent surgery and had acceptable or improved clinical alignment. Radiographic measures used to determine change in genu varum included the anatomic tibio-femoral angle (aTFA), tibia varus, and tibia-fibula ratio. Clinically, changes in lower limb alignment were defined using a plumb line and 6 categories of alignment ranging from extreme varus to valgus. Statistics were used to validate the plumb line categorization to available radiographic measures. Other appropriate statistical methods were used with P < .05 considered significant.Of the 53 PFN cases (27 patients) included in the study, 34 (64%) did not require subsequent surgery and had acceptable or improved alignment. The average age at surgery and follow-up was 6.1 and 17.0 years, respectively. For the 37 limbs (19 patients) with available radiographs, pre- and post-surgery radiographic measures significantly improved including aTFA (3° varus to 2° valgus, P = .003), tibia varus (2° varus to 3° valgus, P = .004), and the tibia-fibula ratio (0.977 to 1.013, P < .001). Clinically, 32 cases (60%) demonstrated significant improvement by translating into an improved alignment and 9 (17%) remained the same (P < .01). Complications were minimal and insignificant. Failures were readily managed by tibia-fibular osteotomies in adolescence and at maturity.PFN for the treatment of genu varum in young achondroplasia patients significantly improved radiographic and clinical measures of lower limb alignment through skeletal maturity with relatively few complications.

Proximal tibiofibular division in lateral closing wedge high tibial osteotomy does not increase varus instability of the knee.

PURPOSE: When performing lateral closing wedge high tibial osteotomy (LCWHTO), fibular untethering can be performed with either fibular shaft osteotomy (FSO) or proximal tibiofibular division (TFD). The aim of this study was to compare the degree of varus instability between the two methods after LCWHTO and to analyze the determinants of varus instability. METHODS: This study retrospectively analyzed 108 consecutive patients with medial compartment osteoarthritis who underwent LCWHTO and had >2 years of follow-up. Patients who underwent unilateral LCWHTO without a previous history of ligament injury were included. Forty-five patients who received LCWHTO with TFD and 51 patients who received LCWHTO with FSO were finally analyzed. The mean follow-up duration was 5.3 years in LCWHTO with TFD and 4.1 years in LCWHTO with FSO. The shortest distance between the lateral tibial plateaus and the corresponding most distal subchondral bone surface of the lateral femoral condyle was measured on varus stress radiographs and compared with that on the unaffected contralateral knee. Multivariable logistic regression analyses were conducted to identify predictors of varus instability. RESULTS: Lateral joint space width showed no significant between-group difference. Multivariable logistic regression analysis revealed that the pre-operative hip-knee-ankle angle was positively correlated with the lateral joint space width. The type of fibular untethering procedure was not associated with postoperative varus instability. CONCLUSION: The degree of pre-operative varus malalignment is associated with postoperative varus instability after LCWHTO. Proximal tibiofibular division is not a variable for postoperative varus instability after LCWHTO. LEVEL OF EVIDENCE: Level III, Retrospective comparative study.

Kinematically Aligned TKA Aligns the Ankle Joint Line Closer to Those of the Native Ankle than Mechanically Aligned TKA in Bipedal Stance.

Mechanically aligned total knee arthroplasty (MATKA) aims to make alignment of the hip, knee, and ankle straight unexceptionally. However, emerging evidence suggests that unexceptional straightening the mechanical axis of the lower limb may lead to clinical and radiological problems of the ankle joint. By contrast, kinematically aligned total knee arthroplasty (KATKA) strives to restore the articular surface of the prearthritic knee. In this study, we examined results from KATKA and MATKA to determine which surgery restores the ankle joint orientation closer to the native ankle joint in bipedal stance and hypothesized that KATKA, rather than MATKA, would be more effective. Data from long-leg standing radiographs of 60 healthy adults (control group, n = 120 knees), patients who underwent MATKA (n = 90 knees), and patients who underwent KATKA (n = 90 knees) were retrospectively reviewed. The hip-knee-ankle angle, orientation of the tibial plafond and the talar dome relative to the ground (G-plafond and G-talus, respectively), and orientation of the plafond relative to the mechanical axis of the limb (M-plafond and M-talus, respectively) were measured and analyzed for comparison. Results show that bipedal stance alignment in patients who underwent KATKA (G-plafond: -0.65 ± 3.03 and G-talus: -1.72 ± 4.02) were not significantly different to native ankle joint alignment indicated by the control group. Compared with the native ankle joint measured in the control group (G-plafond: -0.76 ± 2.69 and G-talus: -1.30 ± 3.25), the tibial plafond and talar dome significantly tilted laterally relative to the ground in ankle joints after MATKA (G-plafond: -2.32 ± 3.30 and G-talus: -2.97 ± 3.98, p = 0.001 and p = 0.004, respectively). Thus, postoperative ankle joint line orientation after KATKA was horizontal to the floor and closer to that of native ankle joints than those after MATKA. The level of evidence is Level III.

Schmid's Type of Metaphyseal Chondrodysplasia: Diagnosis and Management.

OBJECTIVES: There are several types of metaphyseal chondrodysplasia and various clinical types have been differentiated. The Schmid type of metaphyseal chondrodysplasia is the most common. Diffuse metaphyseal flaring, irregularity, and growth plate widening, which are most severe in the knees, are the most striking radiological features of this disease. The Schmid type of metaphyseal dysostosis is characterized by failure of normal mineralization of the zone of provisional calcification, leading to widened physes and enlarged knobby metaphyses, effectively causing shortening of the tubular bones, splaying of the metaphyses, coxa vara, and bow legs. Orthopaedic interventions were primarily performed on the lower extremities. METHODS: Twelve children (seven girls and five boys) aged 7-10 years were enrolled in this study. Moderate short stature was a uniform feature associated with predominant involvement of the proximal femora and bow legs resulted in the development of angular deformities. A waddling gait was a consequence of coxa vara in eight children. Valgus osteotomy of the proximal femur was planned after physeal closure for the group of children with coxa vara. Hemiepiphysiodesis was performed to re-align the genu varum in three children. RESULTS: Other forms of metaphyseal dysostosis were ruled based on full clinical and radiographic phenotypes, with confirmation through molecular pathology. Mutations in the COL10A1 gene located on chromosome 6q21-q22.3 were confirmed. Re-alignment was accomplished in our group of patients. CONCLUSION: The most striking clinical features of Schmid metaphyseal chondrodysplasia which appear within the first 2-3 years of life are: moderate short limbs and short stature, a waddling gait, and increasing shortness of stature with age. The Schmid type of metaphyseal chondrodysplasia is a disorder that arises from defective type X collagen, which is typically found in the hypertrophic zone of the physes. Moderate short stature and a waddling gait associated with pain are the most common clinical presentations. Osteotomies to correct bow legs are sometimes combined with lengthening procedures. Recurrence of the deformities with growth is not uncommon; therefore, hemiepiphysiodesis or stapling might be indicated in some cases.

Bowlegs and Intensive Football Training in Children and Adolescents.

BACKGROUND: In many countries around the world, football (association football, or "soccer" predominantly in North America) is the sport most commonly played by children and adolescents. It is widely thought that football players are more likely to develop genu varum (bowlegs); an association with knee arthritis also seems likely. The goals of this systematic review and meta-analysis are to provide an overview of the available evidence on genu varum after intensive soccer training in childhood and adolescence, and to discuss the possible pathogenetic mechanisms. METHODS: We systematically searched the PubMed, Medline, Embase, and Coch- rane Library databases for studies of the relation between leg axis development and intensive football playing during the growing years. RESULTS: Controlled studies employing the intercondylar distance (ICD) as the target variable were evaluated in a meta-analysis, with the mean difference as a measure of effect strength. This meta-analysis included 3 studies with a total of 1344 football players and 1277 control individuals. All three studies individually showed a signifi- cant difference in the mean ICD values of the two groups. The pooled effect esti- mator for the mean difference was 1.50 cm (95% confidence interval [0.53; 2.46]). Two further studies that could not be included in the meta-analysis had similar con- clusions. Asymmetrical, varus muscle forces and predominantly varus stress on the osseous growth plates neighboring the knee joint, especially during the prepubertal growth spurt, seem to be the cause of this phenomenon. CONCLUSION: Intensive soccer playing during the growing years can promote the devel- opment of bowlegs (genu varum) and, in turn, increase the risk of knee arthritis. Phy- sicians should inform young athletes and their parents of this if asked to advise about the choice of soccer as a sport for intensive training. It cannot be concluded, however, that football predisposes to bowlegs when played merely as a leisure activity.

Effect of arthroscopic resection for discoid lateral meniscus on the axial alignment of the lower limb.

PURPOSE: This study was designed to investigate the changes in the lower limb axial alignment and knee joint function after arthroscopic resection of discoid lateral menisci. METHODS: Pre-operative and post-operative full-length weight-bearing radiographs of the lower limb were obtained from 60 patients with discoid lateral menisci from August 2015 to August 2016. Twenty-four patients were treated with meniscectomy and 36 cases were treated with meniscoplasty. The axial alignment of the lower limb was measured, and changes in the lower limb axial alignment before and after surgery were analyzed. The effects of differing degrees of meniscal resection on the lower limb axial alignment were compared and analyzed. Knee joint function on the affected side was scored using the Lysholm knee scoring, Tegner activity, and International Knee Documentation Committee (IKDC) subjective scales before surgery and one, six and 12 months after surgery. RESULTS: There were apparent changes in the lower limb axial alignment after surgery (p < 0.01). The changes were more conspicuous after a total meniscectomy than a meniscoplasty but were insignificant (p > 0.05). Intragroup comparisons of the Lysholm knee, IKDC, and Tegner scores before and after surgery revealed significant differences (p < 001). However, the differences were not significant between the two surgical approaches (p > 0.05). CONCLUSION: For those with considerable genu varum or genu valgum after surgery, individualized therapy should be developed to correct the lower limb axial alignment and to prevent articular cartilage degeneration. Arthroscopic resection of a discoid lateral meniscus greatly improves knee joint function.

Is a high tibial osteotomy (HTO) superior to non-surgical treatment in patients with varus malaligned medial knee osteoarthritis (OA)? A propensity matched study using 2 randomized controlled trial (RCT) datasets.

OBJECTIVE: No randomized controlled trial (RCT) has compared the high tibial osteotomy (HTO) with non-surgical treatment in patients with medial knee osteoarthritis (OA) and varus malalignment. The aim was to compare the effectiveness of an unloader brace treatment or a usual care program to the HTO regarding pain severity and knee function. DESIGN: Surgical treatment (HTO) to two non-surgical options was compared by combining the data of two RCTs. One RCT (n = 117) compared an unloader brace to usual care treatment; the other RCT (n = 92) compared closing to opening wedge HTO. One-to-many propensity score matching was used to equalize patient characteristics. We compared clinical outcome at 1 year follow-up (VAS pain (0-10) and knee function (HSS, 0-100)) with mixed model analysis. RESULTS: Propensity score matching resulted in a comparison of 30 brace patient with 83 HTO patients, and of 28 usual care patients with 71 HTO patients. Pain at 1 year after HTO (VAS 3.8) was lower than after valgus bracing (VAS 5.0) with a mean difference of -1.1 (95% CI -2.2; -0.1). Function showed a nonsignificant mean difference of 2.1 [95% CI -3.1; 7.3]. Comparing HTO to usual care a difference was seen in pain (-1.7 [95% CI -2.8; -0.6]) and function (6.6 [95% CI 0.2; 13.1]), in favor of the HTO. CONCLUSIONS: Our data suggest that HTO was more effective in pain reduction compared to both non-surgical treatments. Function improved only when HTO was compared to usual care treatment. These small differences question the benefits of surgical treatment over the brace treatment.

Simultaneous bilateral correction of genu varum with Smart frame.

PURPOSE: The aim of this study is to evaluate clinical and radiological results of simultaneous bilateral correction of genu varum with Smart frame. METHODS: Between 2011 and 2015, a total of 25 patients (10 females, 15 males) who had bilateral genu varum deformity were operated bilaterally with tibial and fibular osteotomy in the same session, using Smart frame. The mean follow-up period was 28.7 (range, 13-45) months. All patients had bilateral tibial varus deformity. Femoral deformity was corrected in an earlier session in nine patients. Mechanical axis deviation (MAD), mechanical lateral distal femoral angle, mechanical medial proximal tibial angle (mMPTA) and posterior proximal tibial angle (PPTA) were measured preoperatively and postoperatively. Short Form-36 questionnaire was filled by the patients preoperatively and during the last follow-up. RESULTS: The mean preoperative MAD was 37.6 mm (range, 9-98 mm), which improved to 8.4 mm (range, 3-44 mm) postoperatively ( p < 0.05). The mean preoperative mMPTA was 76°, which improved to 89° ( p < 0.05). The mean preoperative PPTA was 75.5°, which improved to 80.3 ( p < 0.05). Ten problems (20%), two obstacles (4%) and no sequelae occurred in 50 legs of 25 patients. CONCLUSIONS: In conclusion, Smart frame is an accurate and reliable method for performing bilateral simultaneous deformity correction in patients with bilateral genu varum deformity. It can be applied for various childhood-induced severe tibial deformities such as achondroplasia, rickets, skeletal dysplasia and Blount's disease.

Is surgery always indicated in rachitic coronal knee deformities? Our experience in 198 knees.

INTRODUCTION: Defective mineralization of osteoid matrix prior to physeal closure causes rickets. Poor calcification of the cartilage matrix in the zone of provisional calcification causes flattened skull, rachitic rosary, bowed legs, coxa vara and brittle bones. The recent literature has seen an increase in the incidence of the disease in both developing and developed nations. We evaluated behaviour of lower limb deformities due to nutritional rickets in 117 patients. MATERIALS AND METHODS: A prospective study was conducted from January 2009 to December 2011 for clinical and radiological evaluation of knee deformities in nutritional rickets. A total of 117 patients with 198 coronal plane knee deformities between 2 years and 12 years age of rickets were enrolled in this study. RESULTS: In our study, there were 65 genu varum and 133 genu valgum deformities. Seven genu varum (10.7%) and 37 genu valgum (28%) deformities were regarded as failure. Fifty eight genu varum got corrected completely obtaining an average of 5° of valgum in an average of 6.3 months. The average rate of spontaneous correction was 1.9° a month. Ninety six valgum got corrected obtaining an average of 4.7 valgum in an average of 13.3 months. The average rate of spontaneous correction was 0.92° a month. CONCLUSION: Most of the rachitic deformities get corrected with age. Genu varum is having better chances and a faster rate of correction as compared with genu valgum. Early surgery may be indicated in late presenting cases. We believe varum above 4 years and 18° of valgum above 9 years usually do not correct and may require surgical intervention.

Dynamic knee behaviour: does the knee deformity change as it is flexed-an assessment and classification with computer navigation.

PURPOSE: The aim of this study was to assess the kinematics of arthritic knees prior to TKA. The hypothesis was that the arthritic knee follows distinct patterns with regard to deformity in coronal plane as it flexes from extended position. METHOD: Data from 585 consecutive arthritic knees that had undergone TKA using two non-image-based navigation systems were included in the study. Coronal plane alignment given by the femoro-tibial mechanical angle (FTMA) was recorded in extension, 30°, 60°, 90° and maximum flexion prior to making any bony cuts or ligamentous releases. RESULTS: Complete data were available for 512 (87.5 %) of arthritic knees. It was found that pre-implant arthritic knees behaved in different distinct patterns from full extension to 90° flexion. These patterns in FTMA from extension through to 90° of flexion were classified into 4 major types (1, 2, 3, and 4) and 8 subgroups (1A, 1B, 2A, 2B, 3, 4A, 4B, 4C) for varus and valgus knees. Beyond 90° of flexion, there were no distinct or consistent patterns. There were differences between varus and valgus knee deformities not only in overall numbers (73.8 % varus vs. 21.1 % valgus) but also in kinematic behaviour. Only 14.1 % of total knees had a consistent deformity (Type 1A) which remained the same throughout the range of flexion. 14.1 % knees actually become opposite deformity as the knee flexes; thus, varus becomes valgus and valgus becomes varus as the knee flexes (Type 3 and 4C). CONCLUSION: This study has observed and categorised distinct patterns which arthritic knees follow in the coronal plane as it flexes. This dynamic change during flexion will have bearing on collateral releases that are traditionally done based on deformity in extension or 90° flexion mainly. This may be the underlying cause of flexion instability especially for Types 3 and 4C knees if collateral soft tissue release is done based on deformity in extension. Full significance of this remains unknown and will need further investigation. LEVEL OF EVIDENCE: III.

Risk factors of post-operative malalignment in fixed-bearing medial unicompartmental knee arthroplasty.

PURPOSE: The purpose of this study was to identify risk factors of post-operative malalignment in medial unicompartmental knee arthroplasty (UKA) using multivariate logistic regression. METHODS: We retrospectively enrolled 92 patients who had 127 medial UKAs. According to post-operative limb mechanical axis (hip-knee-ankle [HKA] angle), 127 enrolled knees were sorted into acceptable alignment with HKA angle within the conventional ± 3 degree range from a neutral alignment (n = 73) and outlier with HKA angle outside ± 3 degree range (n = 54) groups. Multivariate logistic regression was used to analyse risk factors including age, gender, body mass index, thickness of polyethylene tibial insert, pre-operative HKA angle, distal femoral varus angle (DFVA), femoral bowing angle (FBA), tibial bone varus angle (TBVA), mechanical distal femoral and proximal tibial angles, varus and valgus stress angles, size of femoral and tibial osteophytes, and femoral and tibial component alignment angles. RESULTS: Pre-operative DFVA, TBVA and valgus stress angle were identified as significant risk factors. As DFVA increased by one degree, malalignment was about 45 times probable (adjusted OR 44.871, 95 % CI 2.608-771.904). Shift of TBVA and valgus stress angle to a more varus direction were also significant risk factors (adjusted OR 13.001, 95 % CI 1.754-96.376 and adjusted OR 2.669, 95 % CI 1.054-6.760). CONCLUSIONS: Attention should be given to the possibility of post-operative malalignment during medial UKA in patients with a greater varus angle in pre-operative DFVA, TBVA and valgus stress angle, especially with a greater varus DFVA, which was the strongest predictor for malalignment.

[Results of total knee arthroplasty on excessive genu varum superior to 20°]. / Résultats des prostheses totals du genou sur genou varum excessif supérieur à 20°.

BACKGROUND: Total knee arthroplasty on excessive genu varum is a more demanding technique and gives worst results than procedures on moderate deformations. It remains a subject of controversies due to the lack of consensus. The purpose of our study is to evaluate the results of total knee arthroplasty (TKA) on excessive genu varum (superior to 20°) by analyzing pre and post operative clinical and radiological parameters. METHODS: We reviewed retrospectively 40 TKA in 33 patients (seven patients operated bilaterally) performed for genu varum superior to 20° between 2004 and 2011. Pre and post operative evaluation of patients were done according to the International Knee Society score. RESULTS: The mean age of our patients was 67 years with a female predominance. Tricompartmental arthritis was the etiology in all cases. Pre operative IKS score and HKA angle were respectively 52,36 /200 points and 155,7°. The mean follow up was 4 years. Our results were generally satisfactory. The post operative IKS score was 155,36 points (mean joint score of 85.85 points and mean functional score of 69.26 Points) and the post operative HKA angle was 176,17°. Only 60° of patients had normal HKA angle. We noted aseptic loosening of the tibial component in 3 cases. CONCLUSION: TKA on excessive genu varum is more demanding technique. Pre operative planning after analyzing different clinical and radiological parameters is necessary to obtain a good functional outcome while minimizing the rate of complications.

Recurrent Fever, Anemia, Arthralgia, and Genu Varum as Late Manifestations of Congenital Syphilis.

We report an unusual case of recurrent fever, inflammatory knee pain, genu varum, persistent anemia, and high erythrocyte sedimentation rate in a 28-month-old boy as late manifestations of congenital syphilis (CS). Despite standard penicillin treatment at the end of the first month of life, it recurred later in life, more than once. In the first relapse, manifested by a likely gumma lesion, the prior penicillin treatment plus a negative venereal disease research laboratory result unduly led to exclusion of CS. A second treatment with penicillin led to complete clinical resolution. Although rare, bow legs, recurrent fever, anemia, and inflammatory arthralgias may be manifestations of late CS. Congenital syphilis should be considered throughout early childhood, especially if history of syphilis infection is present. A negative venereal disease research laboratory result does not exclude late syphilis, present in nearly 30% of these patients. The possibility of atypical symptoms of this "great masquerader" should always be borne in mind.