Age and sex differences in coronal lower extremity alignment in a healthy Asian population.

BACKGROUND: The purpose of this study was to analyze the coronal alignment of lower extremities according to age and sex in a healthy population and demonstrate the differences. METHODS: Standing full-lower limb anteroposterior (AP) radiographs of healthy volunteers (670 males and 782 females) aged 18-69 years were retrospectively analyzed. The hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), joint line convergence angle and femoral bowing angle (FBA) were measured. The radiographic parameters were compared according to groups of age and sex. The proportion of volunteers with varus or valgus alignment more than 3° were also analyzed. RESULTS: With increasing age, HKA and LDFA varus increased. With increasing age, femoral medial bowing decreased. In addition, the HKA showed more varus alignment in males than in females (178.01° vs. 178.82°, P < 0.001). The MPTA was about 1° smaller in males than in females (P < 0.001). The proportion of patients with varus alignment of more than 3° increased with increasing age, with 16.9% in the 10-19 years old and 38.0% in the 60-69 years old groups. CONCLUSION: This study demonstrated that males showed more varus tibial alignments than females. Varus limb alignment, LDFA, and FBA also increases with age. In contrast, tibial alignment was constant across all age groups. Therefore, differences in lower extremity alignment according to age and sex should be considered in estimating individual prearthritic alignments.

How Do the Morphological Abnormalities of Femoral Head and Neck, Femoral Shaft and Femoral Condyle Affect the Occurrence and Development of Medial Knee Osteoarthritis.

OBJECTIVE: At present, the main viewpoint is that tibial varus is the main reason of medial knee osteoarthritis (OA), and high tibial osteotomy (HTO) is also the main alignment correction method to correct medial knee OA. In contrast, the impact of the anatomical alignment of the femur on medial knee OA is often overlooked. We evaluated the increased risk for medial knee OA because a varus alignment could be attributed to the anatomical reasons that include hip anatomy, femoral shaft bowing (FSB) and femoral condylar dysplasia. METHODS: The present research adopted a cross-sectional study method. We selected 62 patients with HTO in the Third Hospital of Hebei Medical University from June 2021 to March 2022 as the HTO group and 55 healthy volunteers as the control group. Femoral neck-shaft angle (NSA), lateral FSB, mechanical lateral distal femoral angle (mLDFA) and hip-knee-ankle (HKA) was radiographically examined within the two groups. The femoral neck length and offset were also measured, and the ratio is represented by the ratio of the femoral neck length to off-set (N/O). The 2-tailed Student t-test was used to compare the differences between groups when the data were in accordance with a normal distribution. Otherwise, the Mann-Whitney U tests was used to compare the differences between groups. RESULT: Compared to the control group, the HTO group had a higher offset (p < 0.05), greater femoral neck length (p < 0.05), and decreased (more varus) NSA (p < 0.05). The HKA in the HTO group was 172.20 ° (3.50°), which was significantly lower than that of the control group 177.00° (3.05°), (p < 0.001), while the medial OA was associated with more varus HKA. The mean mLDFA was 89.10 ° (2.35°) and 87.50° (2.85°) in the HTO and control groups (p < 0.005), respectively. The mean lateral FSB values of the full-length radiographs were larger (p < 0.001) in the HTO group (4.24° ± 3.25°) than that in control group (1.16° ± 2.32°). CONCLUSION: The reduction of NSA (coxa vara) and the increase of the mLDFA can lead to medial knee OA, while the lateral FSB also affects medial OA. We believe that femoral deformity is also one of the cause of the medial knee OA. Therefore, it is necessary to evaluate the joint deformity of the femur and tibia before surgery in order to determine whether to use HTO alone to correct the lower limb alignment.

Effect of tibial rotation after uniplane medial open-wedge high tibial osteotomy in genu varum patients: An observational study.

The change in axial tibial rotation after uniplane medial open-wedge high tibial osteotomy (uniplane OWHTO) and its relevant influence factor is not known. Therefore, the aim of this study was to evaluate the change in axial tibial rotation after uniplane OWHTO, and the factors affecting tibia rotational change were analyzed. Between January 2022 and April 2022, the study was retrospectively conducted on genu varum patients who underwent uniplane OWHTO. In the weight-bearing anteroposterior long leg view, the hip-knee-ankle angle and medial proximal tibial angle (MPTA) were evaluated. The posterior tibial slope were measured from the lateral view. A CT scan of the knee joint was performed to evaluate the distal tibial rotation angle (TRA), femorotibial rotation angle and tibial tuberosity-trochlear groove distance. In addition, the foot morphology was assessed by the ankle deformity angle and ankle rotation angle using an angle measuring instrument. All parameters were measured preoperatively and 14 days after surgery. The mean change in hip-knee-ankle, MPTA was 10.5°±2.9°, 8.8°±2.6°. The mean preoperative and postoperative TRA were 25.1°±6.9° and 22.2°±6.2° respectively (P = .007). Thus, the mean ∆TRA was -3.0°±3.4° (IR) with a range of -9.6° to +2.8° after surgery. No significant differences were found in the femorotibial rotation angle and tibial tuberosity-trochlear groove distance before and after surgery (P > .05). The postoperative ankle rotation angle and ankle deformity angle changed significantly compared with preoperative values (P < .001). In the multiple regression analysis, ∆MPTA was the only predictor of distal tibial rotation (ß = 0.667, P = .003). The current study confirms an unintended internal rotation in the distal tibia following uniplane MOWHTO and the rotation in the distal tibia was influenced by the opening width. Surgeron should keep in mind to avoid the osteotomy complication leading to excessive rotation change during surgery.

MAKO robot-assisted total knee arthroplasty cannot reduce the aggravation of ankle varus incongruence after genu varus correction ≥ 10°: a radiographic assessment.

INTRODUCTION: The objective of this study was to investigate the ankle alignment alterations after the correction of knee varus deformity in MAKO robot-assisted total knee arthroplasty (MA-TKA). METHODS: A retrospective analysis was conducted for 108 patients with TKA from February 2021 to February 2022. Patients were divided into two groups based on MAKO robot involvement during the procedure: the MA-TKA group (n = 36) and the conventional manual total knee arthroplasty (CM-TKA) group (n = 72). The patients were divided into four subgroups according to the degree of surgical correction of the knee varus deformity. Seven radiological measurements were evaluated pre and post-surgery: mechanical tibiofemoral angle (mTFA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), tibial plafond inclination angle (TPIA), talar inclination angle (TIA), and tibiotalar tilt angle (TTTA). TTTA is a quantitative representation of the extent of ankle incongruence. RESULTS: The number of mTFA, mLDFA, and MPTA outliers in the MA-TKA group was significantly lower compared to the CM-TKA group (P<0.05). Knee varus deformity was properly corrected and the mechanical axis was restored in all patients, regardless of the treatment group. Only for varus corrections ≥ 10° did TTTA change significantly (p < 0.01) and ankle varus incongruence aggravate post-operation. The ΔTTTA correlated negatively with ΔTFA (r=-0.310,P = 0.001) and correlated positively with ΔTPIA (r = 0.490,P = 0.000). When the varus correction was ≥ 7.55°, the probability of ankle varus incongruence exacerbation increased 4.86-fold. CONCLUSION: Compared with CM-TKA, MA-TKA osteotomy showed more precision but was unable to reduce post-operation ankle varus incongruence. When the varus correction ≥ 10°, ankle varus incongruence aggravated, while when the varus correction ≥ 7.55°, the probability of ankle varus incongruence increased 4.86-fold. This may occasion the pathogenesis of ankle pain following TKA.

High tibial osteotomy for acute correction and subsequent gradual tensioning of the posterolateral knee ligament complex in treating genu varum combined with a lateral thrust using the Ilizarov technique in adults: surgical technique and early results.

OBJECTIVE: To report the early results of using the Ilizarov technique in performing medial wedge opening high tibial osteotomy (MWOHTO) combined with gradual tensioning of the posterolateral corner in adult patients presenting with genu varum (GV) and lateral thrust. METHODS: A prospective case series study included 12 adult patients with a mean age of 25.2 ± 8.1 years who presented with GV deformity associated with lateral thrust. They were evaluated clinically using the "hospital for special surgery" (HSS) knee scoring system. Radiological evaluation was performed using long film from hip to knee to ankle (HKA) radiographs; the overall mechanical alignment was measured as the HKA angle, the upper tibial deformity was measured as the medial proximal tibial angle (MPTA), and the joint line convergence angle (JLCA) was measured. Surgical technique included using Ilizarov for MWOHTO below the level of the tibial tubercle, acute correction of the GV deformity, fibular osteotomy, and gradual distalization of the proximal fibula. RESULTS: After a mean follow-up of 26.3 ± 6.4 months, all osteotomies were united. All patients achieved fibular osteotomy site bony union except two with a fibrous union. The HSS score showed improvement from a mean preoperative score of 88.7 ± 7.6 to a postoperative 97.3 ± 3.9 (P < 0.05). The overall mechanical lower limb alignment improved significantly from a mean preoperative HKA of 164.5 ± 3.2 to a postoperative 178.9 ± 1.6 (P < 0.05). The MPTA improved significantly from 74.6 ± 4.1 to 88.9 ± 2.3, as well as the JLCA from 12.17 ± 1.9 to 2.3 ± 1.7 (P < 0.05). Grade 1 pin tract infection was developed in four patients and was treated conservatively. In two patients, mild pain over the fibular osteotomy site was relieved over time. The lateral thrust reoccurred at the last follow-up evaluation in the two poliomyelitis patients. CONCLUSION: MWOHTO, concomitant with tensioning the knee lateral soft tissue structure at the same setting through applying an Ilizarov apparatus, showed promising functional and radiological outcomes.

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.

Actualización de la osteotomía tibial en el genu varo / Update on tibial osteotomy in genu varum

La osteoartrosis en el compartimento medial de la rodilla es una causa frecuente de dolor cróni-co e impotencia funcional en nuestro medio. Los tratamientos clínicamente efectivos incluyen el tratamiento conservador, la artroplastia unicom-partimental y la osteotomía. Si bien la prótesis unicompartimental puede ser una buena elección en determinados casos, para pacientes jóvenes con una mala alineación de los miembros inferiores se prefieren las osteotomías alrededor de la rodilla con el propósito de redistribuir el eje de carga. Las osteotomías son variadas dependiendo del grado de deformidad y su localización. La más utilizada en la actualidad es la osteotomía tibial valguizan-te, debido a que la mayoría de genu varo artrósico está causada por una deformidad en tibia. Dentro de las osteotomías valguizantes de tibia podemos encontrar: la osteotomía de adición medial, la de sustracción lateral y la osteotomía tridimensional. (AU)

Medial comparment osteoarthritis of the knee is a frequent cause of chronic pain and disability in our environment. Clinically effective treatments include conservative treatment, unicompartmental arthroplasty and osteotomy. Although the unicom-partmental arthroplasty may be a good choice in certain cases, for young patients with lower limb malalingment, osteotomies around the knee are preferred, for the purpose of redistributing the me-chanical axis. Osteotomies are varied depending on the degree of deformity and its location. Valgus tibial osteotomy is the most commonly used, due to the mayority of genu varus arthritis is caused by a tibial deformity. Within the valgus tibial osteoto-mies, we can find: medial opening wedge, lateral closing wedge and tridimensional osteotomy. (AU)

Actualización de la osteotomía tibial en el genu varo / Update on tibial osteotomy in genu varum

La osteoartrosis en el compartimento medial de la rodilla es una causa frecuente de dolor cróni-co e impotencia funcional en nuestro medio. Los tratamientos clínicamente efectivos incluyen el tratamiento conservador, la artroplastia unicom-partimental y la osteotomía. Si bien la prótesis unicompartimental puede ser una buena elección en determinados casos, para pacientes jóvenes con una mala alineación de los miembros inferiores se prefieren las osteotomías alrededor de la rodilla con el propósito de redistribuir el eje de carga. Las osteotomías son variadas dependiendo del grado de deformidad y su localización. La más utilizada en la actualidad es la osteotomía tibial valguizan-te, debido a que la mayoría de genu varo artrósico está causada por una deformidad en tibia. Dentro de las osteotomías valguizantes de tibia podemos encontrar: la osteotomía de adición medial, la de sustracción lateral y la osteotomía tridimensional. (AU)

Medial comparment osteoarthritis of the knee is a frequent cause of chronic pain and disability in our environment. Clinically effective treatments include conservative treatment, unicompartmental arthroplasty and osteotomy. Although the unicom-partmental arthroplasty may be a good choice in certain cases, for young patients with lower limb malalingment, osteotomies around the knee are preferred, for the purpose of redistributing the me-chanical axis. Osteotomies are varied depending on the degree of deformity and its location. Valgus tibial osteotomy is the most commonly used, due to the mayority of genu varus arthritis is caused by a tibial deformity. Within the valgus tibial osteoto-mies, we can find: medial opening wedge, lateral closing wedge and tridimensional osteotomy. (AU)

Influence of femoral bowing on stress distribution of the proximal femur: a three-dimensional finite element analysis.

BACKGROUND: Whether femoral bowing or its direction has a mechanical effect on the proximal femur is unclear. This study aimed to define the changes in stress distribution in the proximal femur associated with femoral bowing using finite element analysis. METHODS: We created four femoral models: original, entire lateral bowing, entire anterior bowing, and the middle of both (50% anterolateral bowing) from computed tomography data of women with standard bowing. Each model's stress distribution was compared by two-layering the stress distribution under loading conditions during walking. We also evaluated displacement vectors. RESULTS: In all directions of femoral bowing, the stress increased in the femoral neck and the femoral trochanter in the 50% anterolateral bowing. The direction of deformation of the vector for the femoral head increased anteroinferiorly in the 50% anterolateral bowing. CONCLUSIONS: This study showed that the stress distribution at the proximal femur shifted laterally. The high-stress area increased at the femoral neck or trochanter due to increasing femoral bowing. Femoral bowing also increases the anteroinferior vector in the femoral head. This study provides valuable insights into the mechanism of proximal femoral fractures in older adults.

Guided growth: angular deformity correction through temporary hemiepiphysiodesis with a novel flexible staple (FlexTack).

Temporary hemiepiphysiodesis (HED) is applied to children and adolescents to correct angular deformities (ADs) in long bones through guided growth. Traditional Blount staples or two-hole plates are mainly used for this indication. Despite precise surgical techniques and attentive postoperative follow-up, implant-associated complications are frequently described. To address these pitfalls, a flexible staple was developed to combine the advantages of the established implants. This study provides the first results of guided growth using the new implant and compares these with the established two-hole plates and Blount staples. Between January 2013 and December 2016, 138 patients (22 children, 116 adolescents) with genu valgum or genu varum were treated with 285 flexible staples. The minimum follow-up was 24 months. These results were compared with 98 patients treated with 205 two-hole plates and 92 patients treated with 535 Blount staples. In long-standing anteroposterior radiographs, mechanical axis deviations (MADs) were measured before and during treatment to analyze treatment efficiency. The evaluation of the new flexible staple was performed according to the idea, development, evaluation, assessment, long-term (IDEAL) study framework (Stage 2a). Overall, 79% (109/138) of patients treated with flexible staples achieved sufficient deformity correction. The median treatment duration was 16 months (interquartile range (IQR) 8 to 21). The flexible staples achieved a median MAD correction of 1.2 mm/month/HED site (IQR 0.6 to 2.0) in valgus deformities and 0.6 mm/month/HED site (IQR 0.2 to 1.5) in varus deformities. Wound infections occurred in 1%, haematomas and joint effusions in 4%, and implant-associated complications in 1% of patients treated with flexible staples. Valgus AD were corrected faster using flexible staples than two-hole plates and Blount staples. Furthermore, the median MAD after treatment was lower in varus and valgus AD, fewer implant-associated complications were detected, and reduced implantation times were recorded using flexible staples. The flexible staple seems to be a viable option for guided growth, showing comparable or possibly better results regarding correction speed and reducing implant-associated complications. Further comparative studies are required to substantiate these findings.

Incidence of adductor tubercle tendinitis and its effect on clinical results in patients with genu varum undergoing high tibial osteotomy.

OBJECTIVE: This study aims to investigate the incidence of adductor tubercle tendinitis (ATT) and demonstrate the effects of intraoperative steroid injections on clinical outcomes in patients undergoing high tibial osteotomy (HTO) due to genu varum (GV). PATIENTS AND METHODS: Of 738 patients who underwent HTO due to GV between 2014-2021, 454 patients had accompanying preoperative ATT. Of these patients, 324 patients who presented to follow-ups and had adequate medical records were evaluated. Mean patient age was 52.6 years. Patients who received steroid injections to the adductor tubercle during HTO (Group I, n=182) and patients who did not receive injections (Group II, n=142) were compared. Univariate and multivariate logistic regression analyses were performed by evaluating preoperative and postoperative VAS scores and presence of ATT. RESULTS: Preoperative ATT sensitivity was present in 61% of the patients. ATT findings were significantly less in Group I compared to Group II in the early-term (1-3 months) (p=0.0001), while there was no significant difference in the late-term (6-12 months) (p=0.880). There was no statistically significant difference between the preoperative and postoperative VAS scores of the groups (p=0.0001). CONCLUSIONS: Stress and tendinitis often develop in the adductor muscle groups due to increased adductor moment in GV. We believe that tendinitis contributes to increased knee pain. HTO reduces the symptoms of tendinitis in the long term by decreasing the adductor moment, while intra-operative steroid injections contribute to relieving complaints related to tendinitis in the early term.

Double level osteotomy for genu varum: Is a return to sport possible?

INTRODUCTION: A double level osteotomy (DLO) may be indicated in patients with genu varum when the deformity involves both the tibia and femur. These patients, who are often young and active, have a high functional demand and hope for a rapid return to sport. The purpose of our study was to assess return to sport and functional outcomes following DLO for symptomatic genu varum. MATERIALS AND METHODS: A total of 40 patients (mean age 45.5±2 years) who underwent a DLO between 2018 and 2020, performed in 2 different hospitals, were reviewed after a minimum follow-up of 1-year. The mean initial varus was 11±2°. The type of sport and frequency of participation (UCLA activity score) as well as time to return to sport and level of activity recovered were defined as the primary endpoints. Functional scores were also assessed with the knee injury and osteoarthritis outcome score (KOOS). RESULTS: At the last follow-up, 87.5% (n=35) of patients reported that they had returned to sport. The mean time to return to sport was 6±1 months with a significant difference (p<0.001) between the pre- and postoperative UCLA activity scores. There was a strong correlation between the presence of a joint line obliquity >3° and decreased functional outcomes (p<0.0001). The overall KOOS score improved (p<0.001) by a mean of 38.6 points after the correction. The 8 lateral cortical fractures (Takeuchi type I and II) and the 2 medial cortical fractures (Nakayama type 1) that were found had no impact on functional outcomes (p>0.05). CONCLUSION: Our findings demonstrated that DLO provided rapid return to sport, thus making it possible to meet the functional demands and expectations of patients. LEVEL OF EVIDENCE: IV; Retrospective study.

Quantitative analysis of lower limb and pelvic deformities in children with X-linked hypophosphatemic rickets.

INTRODUCTION: X-linked hypophosphatemia (XLH) rickets mainly causes leg deformities in children that can worsen as they grow. We hypothesized that quantifying the bone parameters will help to document and monitor these deformities in children with XLH. METHODS: Thirty-five growing children affected by XLH were included in this cross-sectional study. Biplanar radiographs were taken with an EOS system allowing three-dimensional (3D) reconstructions of the pelvis and legs. Sixteen geometric parameters were calculated for the legs and pelvis. A control group of 40 age-matched patients was used to define the reference values for these geometric parameters. RESULTS: For the legs, significant differences (p<0.05) appeared between the XLH patients and the control group in the neck-shaft angle, femur/tibia length ratio and HKS. Among the 70 legs in the XLH group, 23 were in genu varum, 25 were in genu valgum and 22 were straight. There were significant differences between the genu varum and genu valgum subgroups in the femoral mechanical angle and the HKS. A strong correlation was found between the femoral mechanical angle and femorotibial angle (r2=0.73) and between the femoral mechanical angle and HKS (r2=0.69) The sacral slope and acetabular anteversion were significant different from the reference values. DISCUSSION: Quantitative radiological parameters derived from 3D reconstructions show that the deformities in XLH patients are (1) mainly in - but not limited to - the femoral shaft; (2) highly variable from one person to another. Some of these radiological parameters may be useful for the diagnosis and monitoring of XLH patients. LEVEL OF EVIDENCE: III; case control study.

Proximal external femoral torsion increases lateral femoral shaft bowing: a study based on 3D CT reconstruction models.

PURPOSE: Femoral bowing influences the genesis and management of knee osteoarthritis (OA). The aim of this study was to investigate the relationship between the femoral torsion angle (FTA) and femoral bowing angle (FBA) in a southern Chinese population. It was hypothesized that a greater FTA would lead to a greater lateral FBA. METHODS: A total of 381 lower extremities from 381 osteoarthritic patients (298 women, 83 men; 201 left, 180 right; mean age 66.5 ± 8.9 years) were retrospectively reviewed. Age, sex, body mass index (BMI), side, height, femoral length (FL), hip-knee-ankle angle (HKA) and FTA were set as FBA-related factors. The three-dimensional (3D) FBA, the angle between the anatomical axis of the proximal femur and the anatomical axis of the distal femur in the plane they form, and its projection on the coronal (lateral FBA) and sagittal (anterior FBA) planes were measured on 3D computed tomography (CT) models. The correlation of the 3D, lateral and anterior FBAs with each of the FBA-related factors was explored using multiple linear regression analysis. The correlation between the FBA and FTA was explored and verified after using propensity score matching to control for the other FBA-related factors. RESULTS: The mean lateral and anterior FBAs were 5.5°, with 53.5% greater than 5°, and 12.7°, with 70.3% greater than 11°, respectively. 3D FBA was positively correlated with age (Std.Co = 0.113, P < 0.05) and HKA (Std.Co = 0.129, P < 0.05). Lateral FBA was positively correlated with age (Std.Co = 0.118, P < 0.05), female sex (Std.Co = 0.206, P < 0.05), HKA (Std.Co = 0.184, P < 0.05) and FL (Std.Co = 0.220, P < 0.05). Anterior FBA was positively correlated with age (Std.Co = 0.108, P < 0.05) and male sex (Std.Co = 0.108, P < 0.05). When the related factors were balanced between the two groups (NS), FTA did not significantly affect 3D FBA or anterior FBA (NS), while FTA was positively correlated with lateral FBA (Std.Co = 0.165, P < 0.05). CONCLUSION: External torsion of the proximal femur increases the lateral FBA by twisting a partial anterior FBA into a lateral FBA, especially in the female population. If a patient is found to have a large lateral FBA preoperatively, one should be alert to the possibility of a concomitant large FTA, as there are implications for femoral orthopedics, TKA and patellofemoral pressure distribution. LEVEL OF EVIDENCE: III.

Femoral bowing affects varus femoral alignment but not patient satisfaction in mechanically aligned total knee arthroplasty.

PURPOSE: This study evaluated whether patients with particular lower limb morphological factors have femoral and tibial component malpositioning during mechanically aligned total knee arthroplasty (TKA) and lower postoperative satisfaction. METHODS: This study included 146 knees in 117 Asian patients undergoing TKA for medial osteoarthritis. Preoperative bony morphological factors such as the angle between the femoral mechanical and anatomical axes (MA-AA angle), angle between the anatomical axes of the proximal and distal femur (lateral bowing femoral angle, LBFA), mechanical lateral distal femoral angle, medial proximal tibial angle, and % anatomical axis of the tibia were evaluated, as well as preoperative and 1-year postoperative 2011 Knee Society scores (KSSs). RESULTS: MA-AA angle and LBFA were significantly larger in knees with varus femoral component alignment versus neutral alignment. Preoperative MA-AA angle was underestimated in patients with larger MA-AA angle or LBFA, especially by inexperienced surgeons. Tibial morphological factors did not affect tibial component alignment. Changes in 2011 KSSs were similar among groups by lower limb alignment or femoral and tibial component alignment. CONCLUSION: Femoral bowing affects varus femoral component alignment by obscuring preoperative planning, but it had little impact on patient satisfaction when mechanical alignment is targeted during TKA.

"One millimetre equals one degree": a simple way to achieve in 92% of cases the desired correction after opening proximal tibial osteotomy for genu varum.

INTRODUCTION: When performing a high tibial osteotomy (HTO) for genu varum deformity, it is not always easy to obtain the correct amount of overcorrection. The aims of this study were to review the results of a simple and reproducible method of correction that we have called "1 mm equals 1°". We have applied this technique to the medial opening wedge osteotomy. Our hypothesis was that one degree of correction corresponded with one degree of opening. METHODS: 97 proximal medial opening wedge osteotomies were measured intraoperatively with a navigation system and at 3 months with long-leg X-rays. The hip-knee-ankle (HKA) angle preoperatively was on average 173.8 ± 2.3° (170°-177°). In most cases, an opening of 4° greater than the initial varus was performed using our formula that one degree varus was equal to 1 mm of opening. In other words, when the varus was 6°, an opening of 10 mm was performed. The void left by the opening wedge was filled with a calcium triphosphate wedge and the construct fixed and held with a locking plate. RESULTS: Aiming for a knee axis of 184 ± 2°, which corresponds to 2°-6° of overcorrection, we obtained the following results: HKA intraoperatively measured angle with navigation was on average 183.5 ± 0.9° (182°-184°) and HKA radiologically postoperatively angle was 182.5° ± 1.6° (179°-189°). We therefore achieved the desired overcorrection of 2°-6° in 92% of cases based on our postoperative radiographs and in 100% cases based on intraoperative measurements with computer navigation. CONCLUSION: The method of "1 mm equals 1°" is a simple, reliable, and reproducible method to achieve in 92% of cases the desired overcorrection (i.e., 184 ± 2°) with valgising proximal medial opening wedge osteotomy in genu varum.

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

BACKGROUND: 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. METHODS: 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. 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±7.6 mm, 97.2±6.4, and 80.3±4.3 degrees, and 11±15.6 mm, 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. CONCLUSIONS: Growth modulation by TBP surgery is a reliable and simple technique to correct genu varum in achondroplasia. An early age at TBP implementation (mean: 6.5 y) is crucial to successfully correct the varus knee deformity. Furthermore, we recommend early and regular surveillance of achondroplasia for progressive varus knee deformity. LEVEL OF EVIDENCE: Level IV-cohort study.

Atypical fractures of the ulna: Effect of bowing of the ulna on fracture location and occurrence.

INTRODUCTION: Ulnar fractures associated with long-term bisphosphonate (BPs) therapy are rare, and the nature and extent of this potential risk remains unknown. Although ulna is generally considered a "straight bone", it actually features a bow anatomically. For this reason, we speculated that ulnar bow may have a role in the development of atypical ulnar fractures (AUFs). Therefore, we compared the location and depth of ulnar bow between AUF patients and patients with atypical fractures other than the ulna. We aimed to answer: (1) whether a correlation exists between the location of the ulna bow and the location of AUFs, (2) whether the degree of ulnar bow affects the occurrence of AUFs. HYPOTHESIS: Ulnar bowing could play a critical role in the location and occurrence of AUFs. METHODS: We retrospectively reviewed the radiographs and medical records of 64 patients with atypical fractures admitted to our department between May 2010 to July 2020. The bow of the ulna was measured using anteroposterior (AP) and lateral radiographs. Bone angulation was described as apex of deformity, with apex lateral bow designated as AP plane bowing and apex posterior bow marked as lateral plane bowing. RESULTS: In all patients with atypical fractures, bow locations were measured at the proximal third level to the index line in 68% of AP plane and 72% of lateral plane. In patients with AUFs, fracture sites occurred in the range of 20% to<40%, except in one patient. Fracture site versus apex lateral bow location and fracture site versus apex posterior bow location showed a statistically significant correlation coefficient of 0.81 (p<0.001) and 0.69 (p=0.003), respectively. In lateral plane, there was a significant difference between AUF patients and patients with atypical fractures other than the ulna in ulnar bow depth (p=0.014). However, no statistically significant differences were found in AP plane (p=0.110). DISCUSSION: In AUFs, fracture site was highly correlated with ulnar bowing location, and, as the degree of apex posterior bow increased, occurrence of AUFs increased. These findings are helpful in understanding the role of bowing as the ulnar geometry in the development of AUF and early identification of the location of suspicious AUF. LEVEL OF EVIDENCE: IV.

Navigation makes more accurate femur resection compared to conventional total knee arthroplasty in lateral femoral bowing greater than 5º.

There are many disagreements about the merits of navigation in total knee arthroplasty (TKA). We compared and analyzed the difference in the accuracy of femoral resection according to the degree of lateral femoral bowing in 2 surgical methods (conventional and navigation-assisted TKA). A total of 238 (100 who underwent navigation TKA and 138 who underwent conventional TKA from 2016 to 2021) were included in this study. The surgeon first performed TKA as the main operator in 2016. Most of the TKAs were navigation-assisted between 2016 and 2018, and most of the TKAs were conventional between 2019 and 2021. For more accurate distal femoral cutting in patients with lateral femoral bowing, a preoperative scanogram was used to set up the insertion point of the IM rod in conventional TKA. Femoral lateral bowing was divided into 3 groups based on the angle. Group 1 was divided into groups with negative values, group 2 into mild bowing of 0° to 5°, and group 3 into groups with moderate bowing of ≥ 5°. The postoperative mechanical hip knee ankle angle and mechanical lateral distal femoral angle (mLDFA) were aimed to be 0° and 90°. The allowable ranges of these values were set as 0°â€…±â€…3° and 90°â€…±â€…3°, respectively. The distribution of outliers of the mLDFA in the 3 groups divided according to lateral femoral bowing in the navigation-assisted group was not statistically significant difference (P = .59). On the other hand, the distribution of outliers of mLDFA was statistically significant difference in the conventional method group (P = .01). The odds ratio of the outlier occurrence of mLDFA in the conventional method was 2.50, which was statistically significant (P = .03). Also, when the lateral femoral bowing value was moderate; i.e., ≥5°, the odds ratio was 4.20, which was statistically significant (P = .003). In the case of navigation-assisted TKA, the accuracy of femur resection was consistent regardless of the degree of lateral femoral bowing. However, in conventional TKA, the outlier of femur resection increased as lateral femoral bowing increased. Especially, for patients with lateral femoral bowing >5°, navigation-assisted TKA allows for more accurate femur resection compared to conventional TKA.

Tratamiento quirúrgico del raquitismo hipofosfatémico con deformidad en genu valgo: a propósito de un caso / Surgical treatment of hypophosphatemic rickets with genu valgus deformity: apropos of a case

El raquitismo hipofosfatémico es un trastorno caracterizado por hipofosfatemia, deficiencia de la absorción intestinal de calcio y raquitismo u osteomalacia que no responde a la vitamina D. Los síntomas son dolor óseo, fracturas y alteraciones del crecimiento. Raquitismo hipofosfatémico es un defecto en la mineralización ósea, originado por alteraciones metabólicas de calcio y fosfatos, siendo características la hiperfosfaturia e hipercalciuria; produce deformidades angulares óseas, la más importante de ellas es el genu varo. Presentamos el caso de paciente masculino, atendido en la Ortopedia Pediátrica Callisperis, diagnosticada con raquitismo hipofosfatémico. Acude al Servicio con un seguimiento de 2017 a 2021, con 13 años de edad, quien presentaba una importante deformidad en genu valgo un caso relativamente infrecuente, la presentación común del Raquitismo hipofosfatemico es el genu varo , así como deformidad progresiva de las extremidades inferiores, con antecedente de tratamiento con grapas de Blaunt sin observarse mejoría; a la exploración física destaca una talla baja, además de angulación en valgo en ambas rodillas 20°, así como hipofosfatemia y fosfaturia. El tratamiento se realizó de forma multidisiplinaria por parte de endocrinología con calcitriol y fosfatos, además de fisiodesis en ambas rodillas a nivel femoral y tibial bilateral mediante placas en ocho previamente retirando las grapas de Blaunt dicho tratamiento fue insatisfactorio, se realizó los controles correspondientes una vez finalizado su crecimiento y con las fisis cerradas se retira implantes.

Hypophosphatemic rickets is a disorder characterized by hypophosphatemia, impaired intestinal calcium absorption, and rickets or osteomalacia that does not respond to vitamin D. Symptoms include bone pain, fractures, and growth disturbances. Hypophosphatemic rickets is a defect in bone mineralization, caused by metabolic alterations of calcium and phosphates, hyperphosphaturia and hypercalciuria being characteristic; produces angular bone deformities, the most important of which is the genu varus. We present the case of a male patient, treated at the Callisperis Pediatric Orthopedics, diagnosed with hypophosphatemic rickets. He attended the Service with a follow-up from 2017 to 2021, with 13 years of age, who presented an important deformity in genu valgus a relatively infrequent case, the common presentation of hypophosphatemic rickets feels the genu varus, as well as progressive deformity of the lower extremities , having previously been treated with Blaunt staples without observing improvement; Physical examination revealed short stature, in addition to 20 ° valgus angulation in both knees, as well as hypophosphatemia and phosphaturia. The treatment was carried out in a multidisciplinary way by endocrinology calcitriol and phosphates, in addition to physiodesis in both knees at the femoral and bilateral tibial level by means of plates in eight previously removing the Blaunt staples, said treatment was unsatisfactory, the corresponding controls were carried out once finished its growth and with closed physis implants are removed.