Hip-to-calcaneus alignment differs from hip-to-talus alignment in patients with genu varum deformity.

PURPOSE: To (1) compare the weight-bearing line (WBL) ratios of the knee joints measured using the conventional (hip-to-talus radiographs, HTRs) and novel (hip-to-calcaneus radiographs, HCRs) orthoradiograms, (2) compare the hip-knee-ankle (HKA) angle between cases with < 5% and > 5% differences in WBL ratios between two orthoradiograms, and (3) investigate the optimal cutoff value (COV) of the HKA angle causing inconsistency in the orthoradiograms. METHODS: Sixty limbs of 31 patients with HTR and HCR records were retrospectively reviewed. After drawing the mechanical axis on each radiograph, the WBL ratios of the knees were calculated and compared between the conventional and novel orthoradiograms. In subgroup analysis, cases with < 5% and > 5% differences in WBL ratios between two orthoradiograms were classified as consistent and inconsistent groups, respectively. Receiver operating characteristic curve based on the HKA angles of the lower limbs was used to identify the COV causing the inconsistency between the orthoradiograms. RESULTS: Inter- and intra-rater reliabilities of all radiologic measurements were > 0.75. The WBL ratios showed no significant difference between the two orthoradiograms. However, the HKA angle was significantly larger in the inconsistent group than in the consistent group (7.0° ± 1.8° vs. 4.4° ± 2.5°; P < 0.001). The COV of the HKA angle that caused inconsistency in the two orthoradiograms was 4.0° (area under the curve, 0.774). CONCLUSION: The hip-to-calcaneus alignment differed significantly from the hip-to-talus alignment in patients with genu varum deformity. HCR measurement can be a complementary method for planning corrective osteotomy for patients with genu varum deformity. LEVEL OF EVIDENCE: IV.

Increased external rotation of the osteoarthritic knee joint according to the genu varum deformity.

PURPOSE: To evaluate the rotational profile of the lower extremity using computed tomography (CT) in accordance with the degree of varus deformity in medial condyle-affected knee joint osteoarthritis (OA). METHODS: This retrospective study included 1036 patients (872 lower extremities) with end-stage knee OA. The coronal alignment of the lower extremity was measured using standing anteroposterior radiography. The CT parameters of femoral anteversion and tibial torsion were assessed in relation to the knee joint. The axes were the femoral neck axis; the distal femoral axis, which was composed of the anterior trochlear axis, the clinical transepicondylar axis, and the posterior condylar axis; the axis of the proximal tibial condyles; and the bimalleolar axis. RESULTS: There was a tendency for increased external rotation of the knee joint parameters in relation to the hip and ankle joints as varus deformity of the lower extremity increased. The relative external rotational deformity of the knee joint in relation to the hip joint had a positive value with a good correlation. The relative external rotational deformity of the knee joint in relation to the ankle joint also demonstrated a positive value with a good correlation. CONCLUSION: The distal femur and proximal tibia (knee joint) tended to rotate externally in relation to the hip and ankle joint, respectively, as the degree of varus deformity increased. This study identified the relationship between lower extremity varus deformity and rotational deformity of knee joints with OA. LEVEL OF EVIDENCE: III.

How coronal alignment affects distal femoral anatomy: an MRI-based comparison of varus and valgus knees.

PURPOSE: In contemporary total knee arthroplasty (TKA), most often, the goal is to align the femoral component to the epicondylar axis (EA). The posterior condylar axis (PCA) is easier to define than the EA, and thus the relationship of PCA to the EA is then used instead to align the femoral component to the EA. However, the relationship of PCA to EA is not constant and has been reported to differ between varus and valgus knees and with increasing deformity. The aim of this large MRI-based study was to evaluate the relationship between PCA and EA with varying coronal deformity especially with increasing valgus deformity. METHODS: EA, PCA, AP (Whiteside's line) and the mechanical axis were obtained from 474 magnetic resonance imaging (MRI) scans used to create patient-specific instrumentation (PSI) for the Biomet Signature (Warsaw, NJ) system. RESULTS: The relationship of EA relative to the PCA showed considerable heterogeneity in both varus and valgus groups. In the valgus group, there was statistically greater external rotation (P < 0.05) of the EA from the PCA with a mean of 2.52° (range - 1.9° to 6°) compared to the varus group with a mean of 2.03° (range - 3.9° to 6.9°). This relationship did not significantly change with increasing severity of coronal malalignment. Externally rotating the femoral cutting guide by 3° from the PCA, 11% (42 of 382) of varus knees would lie outside of ± 3° from EA. In valgus knees, externally rotating the femoral cutting block by 3° or 5° from the PCA, 6.5% (6 of 92) and 33.7% (31 of 92) of knees, respectively, would lie outside of ± 3° from EA. CONCLUSION: The relationship of PCA to EA is heterogeneous and is not altered significantly with increasing valgus coronal deformity. External rotation beyond 3° from PCA in valgus knees may lead to significant femoral component malrotation in a large proportion cases.

High occurrence of osteoarthritic histopathological features unaccounted for by traditional scoring systems in lateral femoral condyles from total knee arthroplasty patients with varus alignment.

Background and purpose - A better understanding of the patterns and variation in initiation and progression of osteoarthritis (OA) in the knee may influence the design of therapies to prevent or slow disease progression. By studying cartilage from the human lateral femoral condyle (LFC), we aimed to: (1) assess specimen distribution into early, mild, moderate, and severe OA as per the established histopathological scoring systems (HHGS and OARSI); and (2) evaluate whether these 2 scoring systems provide sufficient tools for characterizing all the features and variation in patterns of OA. Patients and methods - 2 LFC osteochondral specimens (4 x 4 x 8 mm) were collected from 50 patients with idiopathic OA varus knee and radiographically preserved lateral compartment joint space undergoing total knee arthroplasty. These were fixed, sectioned, and stained with HE and Safranin O-Fast Green (SafO). Results - The histopathological OA severity distribution of the 100 specimens was: 6 early, 62 mild, 30 moderate, and 2 severe. Overall, 45/100 specimens were successfully scored by both HHGS and OARSI: 12 displayed low OA score and 33 displayed cartilage surface changes associated with other histopathological features. However, 55/100 samples exhibited low surface structure scores, but were deemed to be inadequately scored by HHGS and OARSI because of anomalous features in the deeper zones not accounted for by these systems: 27 exhibited both SafO and tidemark abnormal features, 16 exhibited only SafO abnormal features, and 12 exhibited tidemark abnormal features. Interpretation - LFC specimens were scored as mild to moderate OA by HHGS and OARSI. Yet, several specimens exhibited deep zone anomalies while maintaining good surface structure, inconsistent with mild OA. Overall, a better classification of these anomalous histopathological features could help better understand idiopathic OA and potentially recognize different subgroups of disease.

Evaluation of the size and position of the insertion of the anterior medial meniscus root in varus osteoarthritic knees.

PURPOSE: Recent studies have suggested radial displacement of the medial meniscus as a cause of varus knee osteoarthritis (OA). Two anatomical studies reported that such displacement may be associated with anterior insertion of the medial meniscus anterior horn. It was aimed to evaluate the location and area of this insertion in patients with advanced knee OA. METHODS: Medial meniscus anterior horn insertions were classified into four types, as described in a previously reported classification during 225 total knee arthroplasty (TKA) in 184 patients. The incidence rates of insertion type were compared with previously reported rates in nearly normal or non-arthritic knees. The insertion surface area was also measured during 158 TKAs. RESULTS: Of the 225 knees, 82 (36.4 %), 93 (41.3 %), 35 (15.6 %), and 15 (6.7 %) were classified as I, II, III, and IV, respectively. An anteriorly inserted anterior horn was not more frequent in advanced varus OA knees than in previously reported nearly normal or non-arthritic knees. The insertion surface areas were 57.5 ± 18.9, 56.1 ± 16.0, and 56.4 ± 14.4 mm2 for types I, II, and III, respectively; these areas did not differ significantly. CONCLUSION: Since the incidence of an anteriorly inserted medial meniscus anterior horn was not higher in advanced varus OA knees than in normal or non-arthritic knees, an anteriorly inserted anterior horn may have little or no effect on the aetiology of varus OA knees. This study provides some information for clarifying the aetiology of knee OA. LEVEL OF EVIDENCE: IV.

The Efficacy of Percutaneous Lateral Hemiepiphysiodesis on Angular Correction in Idiopathic Adolescent Genu Varum.

BACKGROUND: Percutaneous lateral hemiepiphysiodesis of the lower extremity is a simple and excellent method to correct the angular and length problems cosmetically. However, the efficacy of percutaneous lateral hemiepiphysiodesis is not well established in the literature. The purpose of this study was to evaluate the efficacy of percutaneous lateral hemiepiphysiodesis for angular corrections in adolescent idiopathic genu varum patients with proximal tibia vara and identify the factors affecting the amount of deformity correction of the lower limb in the coronal plane. METHODS: We retrospectively reviewed 20 patients (40 lower limbs) who had percutaneous lateral hemiepiphysiodesis on the proximal lateral tibia between 1997 and 2010. Radiographic evaluations were made using (1) the hip-knee-ankle angle and (2) the length of the tibia. Furthermore, the intercondylar distance was evaluated at the level of the knee joint. Preoperative factors (gender, age, body mass index, intercondylar distance, preoperative hip-knee-ankle angle, remaining growth of tibia, and calculated correctable angle) were analyzed, as well as their correlation with the degree of the actual correction angle. RESULTS: The amount of coronal deformity of the lower limb was improved from its preoperative state. The median average of hip-knee-ankle angle improved from 8.0° (interquartile range [IQR], 7.0° to 10.0°) preoperatively to 3.0° (IQR, 2.5° to 4.0°) at the final follow-up (p < 0.001). The median percent ratio of the angular correction was 60% (IQR, 50% to 71.3%). The correlation coefficients were -0.537, 0.832, 0.791, and 0.685 for the bone age, preoperative hip-knee-ankle angle, the remaining growth of tibia, and calculated correctable angle, respectively. CONCLUSIONS: Despite the excellent cosmetic outcome of percutaneous lateral hemiepiphysiodesis on the proximal lateral tibia in adolescent idiopathic genu varum, the effect was limited in most cases. For optimum results, surgery a few months earlier is recommended, rather than at the calculated operation time.

[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.

Multilevel guided growth for hip and knee varus secondary to chondrodysplasia.

BACKGROUND: Young children with chondrodysplasia may develop multilevel varus deformities that compromise comfort and gait. The classic treatment of performing corrective, staged osteotomies, at each level of deformity, is a daunting prospect that is fraught with potential complications. To avoid this scenario, we have adopted single-event, multilevel surgery, using guided growth to simultaneously address bilateral varus deformities of the knee and hip, with good results. METHODS: Three cousins with Schmid-type metaphyseal dysplasia, presented for treatment of progressive varus deformities. In lieu of osteotomies, we used simultaneous guided growth of the proximal and distal lateral femora and proximal lateral tibiae, while ignoring the distal tibial deformity. The pan-genu 8-plates served to neutralize the mechanical axis while preserving a horizontal knee. The rationale for applying the trochanteric 8-plate was to stabilize the proximal femoral chondroepiphysis, hoping to postpone or avert intertrochanteric osteotomy. The average age at surgery was 28 months, with a range of 19 to 33 months, and follow-up has ranged from 28 to 59 months (average 48 mo). The pan-genu 8-plates were removed after an average of 12 months, leaving the trochanteric implants in situ, pending further growth. RESULTS: Neutralization of the mechanical axis resolved lateral knee thrust and intoeing. As the femur is effectively adducted by knee realignment, the greater trochanteric impingement on the ilium is alleviated. Lateral tethering of the trochanteric apophysis served to increase the femoral neck-shaft angle, improving the abductor lever arm. Each patient experienced complete resolution of the fatigue hip pain and Trendelenburg gait. As knee alignment was restored, the ankle varus resolved spontaneously, requiring no direct treatment. The clinical improvement was reflected in trending of the radiographic angles and axes toward normal. CONCLUSIONS: These children have benefited from outpatient guided growth, rather than the anticipated osteotomies, to correct multilevel varus deformities. Our goal is to exclusively use guided growth, repeatedly as needed, to avoid osteotomies altogether. Annual follow-up until skeletal maturity is planned. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Role of the mechanical axis of lower limb and body weight in the horizontal tear and root ligament tear of the posterior horn of the medial meniscus.

PURPOSE: To compare and analyse the relationship between horizontal tear and root ligament tear of the posterior horn of the medial meniscus (PHMM) and the degree of varus in the axis of lower limb and body weight. METHODS: One hundred and nineteen patients underwent surgical treatment as they were diagnosed with medial meniscus tear in our hospital from May 2006 to December 2009. Of these, 19 cases (group 1), underwent partial meniscectomy as they were confirmed to solely have horizontal tear of the PHMM on arthroscopic examination and 27 cases (group 2), underwent subtotal meniscectomy as they were confirmed to solely have root ligament tear of the PHMM on arthroscopic examination, were chosen for retrospective study. Standing radiographs were taken of every case prior to arthroscopic surgery to measure varus angle. Also, we checked body mass index (BMI) of two groups. The difference of varus angle and BMI between two groups were statistically verified using the Levene's test, paired t-test. RESULTS: Group 1 showed mean value of varus angle of 2.30 ± 0.54, and BMI of 25.32 ± 3.23. Group 2 showed mean value of varus angle of 5.64 ± 0.54, and BMI of 25.67 ± 3.12. The degree of varus of group 2 was statistically significantly higher than group 1 (p = 0.002). Comparison between the BMI of two groups showed no statistical significance (p = 0.053). CONCLUSION: Through a comparative study of sole horizontal tear and root ligament tear of the PHMM, the authors have found that sole root ligament tear of the PHMM is more relative to the genu varum than sole horizontal tear of the PHMM. However, body weight was statistically irrelevant to the incidence of the two lesions.

Interpopliteal distance percentiles to diagnose bowleg in 0-84 month-old Turkish children.

The purpose of this study was to determine the percentiles of interpopliteal distance to diagnose bowleg in 0-6 year-old children. Measurement of interpopliteal distance is a simple but valuable indicator in clinical examination to diagnose bowleg. We analyzed data from the anthropometry of Turkish children aged 0-6 years. The primary sampling unit included 21 family health centers (Aile Sagligi Merkezi) located in the city center and suburbs of Kayseri, Turkey. A total of 2,873 children and adolescents (1,419 boys, 1,454 girls), whose parents gave consent were included in the study. The smoothed percentiles and Z-scores were calculated by age and gender in 0-6 year-old children in quarter year intervals except for the 0-28-day newborn period. We found a significant correlation (r: 0.60, p < 0.001) between body weight and interpopliteal distance (after onset of walking). We consider that percentiles of interpopliteal distance can be used in the follow-up of children who may be at risk of bone and growth disorders. The zone between -2 standard deviation (SD) and +2SD values can be used to decide if the child has a normal growth pattern.

Open-wedge osteotomy using an internal plate fixator in patients with medial-compartment gonarthritis and varus malalignment: 3-year results with regard to preoperative arthroscopic and radiographic findings.

PURPOSE: Our purpose was to evaluate the 3-year clinical results of patients with medial-compartment osteoarthritis of the knee and varus malalignment who underwent open-wedge high tibial osteotomy (HTO) with an internal plate fixator (TomoFix; Synthes, Solothurn, Switzerland). Clinical results are correlated with arthroscopic and radiographic findings at the time of surgery. METHODS: This study included 69 patients with a minimum follow-up of 36 months who underwent open-wedge HTO for medial-compartment osteoarthritis of the knee. Knee function was assessed before surgery and at 6, 12, 24, and 36 months after HTO by use of subjective International Knee Documentation Committee and Lysholm scores. Arthroscopic findings before HTO and radiographic assessment of the metaphyseal deformity of the proximal tibia (tibial bone varus angle) were correlated with clinical outcome. RESULTS: A significant continuous increase in International Knee Documentation Committee score from 47.25 ± 18.71 points before surgery to 72.72 ± 17.15 points at 36 months after HTO was found (P < .001). Grade of cartilage damage of the medial compartment and partial-thickness defects of the lateral compartment did not significantly influence clinical outcome (P > .05 at all time points). The tibial bone varus angle was correlated significantly with greater improvement and better clinical outcome after HTO (P < .01). The overall complication rate of 8.6% was mostly related to surgical causes; nevertheless, a high proportion of patients reported discomfort related to the implant at some point during the follow-up period (40.6%). CONCLUSIONS: Open-wedge osteotomy by use of the TomoFix system leads to reliable 3-year results. Results do not depend on the severity of medial cartilage defects, whereas partial-thickness defects of the lateral compartment seem to be well tolerated. The prognostic relevance of patellofemoral cartilage defects remains unclear. Local irritation of the implant was observed in a significant number of patients. LEVEL OF EVIDENCE: Level IV, therapeutic case series.