Nonossifying fibroma of the lower femur with genu valgum: a case report.

BACKGROUND: Nonossifying fibroma is common in children and adolescents, and nonossifying fibroma with genu valgum is rare in the clinic. This article evaluated the effectiveness of treatment in a case of nonossifying fibroma of the lower femur with genu valgum. CASE PRESENTATION: A 16-year-old girl complained of pain in the lower part of her right thigh for one year. She was diagnosed as non ossifying fibroma of the right femur with secondary valgus deformity of the right knee, and was treated in our hospital. We performed curettage, bone grafting and internal fixation,and corrected the valgum deformity at the same time. The patient's incision healed well, the pain was disappeared, and the mechanical axis of lower limbs was corrected. No tumor recurrence was found on X- ray examination one year after operation, and the fracture end was healed. The patient could walk normally, and she was satisfied with her limb function. CONCLUSION: Nonossifying fibroma with genu valgum is rare in the clinic. The patient was satisfied with our treatment, which achieved a good curative effect.

The Fate of Overcorrection After Hemiepiphysiodesis in Valgus Deformities Around the Knee.

BACKGROUND: Tension band plating is widely used in the surgical treatment of coronal plane deformities around the knee. The rebound phenomenon after implant removal is a common complication of this technique. Overcorrection of joint orientation angles is a method to minimize the effect of the rebound phenomenon. This study aims to investigate the natural course of overcorrected joint orientation angles after plate removal in patients with genu valgum deformity. METHODS: Patients who underwent hemiepiphysiodesis with tension band plating due to genu valgum deformity between 2010 and 2019 were retrospectively analyzed. Mechanical lateral distal femoral angles (mLDFA) and mechanical medial proximal tibial angles were calculated before plate application, before implant removal, and at the last follow-up. At the implant removal, mLDFA>90 degrees and mechanical medial proximal tibial angles <85 degrees were accepted as overcorrected. RESULTS: Seventy-two segments from 45 patients were included. For femoral valgus deformities (n=59), the mean mLDFAs at index surgery, implant removal, and the last follow-up were 79.8±3.9 degrees, 95.5±3.7 degrees, and 87.3±5.1 degrees, respectively. In the more and less than 10 degrees rebound groups, the median age of patients at index surgery were 66 and 101 months ( P =0.04), the mLDFA during implant removal were 97.8 degrees and 94.4 degrees ( P =0.005), and the mean amount of correction in mLDFA was 17 degrees and 13 degrees ( P =0.001), respectively. At the last follow-up, joint orientation angles were found to be still overcorrected in 16 (22%), within normal limits in 36 (50%), and undercorrected in 20 (28%) segments. Ten (13%) segments required additional surgery due to residual deformity. CONCLUSIONS: Overcorrection with tension band plating is an effective modality in the treatment of genu valgum deformity. Rebound after plate removal increases as the age at index surgery decreases and the amount of conscious overcorrection increases. Most segments return to normal joint orientation angle limits after overcorrection. We recommend a mean of 5 degrees routine overcorrection in patients with genu valgum deformity to overcome the rebound phenomenon and to make future interventions easier if ever needed. LEVEL OF EVIDENCE: Level III.

Patient-reported Outcomes of Adolescents Treated With Guided Growth to Correct Idiopathic Genu Valgum.

BACKGROUND: Guided growth is commonly used to treat frontal plane alignment deformities in skeletally immature individuals. Treatment aims are to correct the biomechanical loading of the knee and to avoid more invasive surgery that would be required after skeletal maturity. There is little published evidence of pain perception or functional limitations in this population. In addition, the intervention has the potential to worsen pain and function with hardware implantation, and symptoms may not fully resolve after removal. Understanding of pain and function limitations in this population is important to guide the clinical expectations. METHODS: Individuals with idiopathic knee genu valgum who underwent hemiepiphysiodesis with tension plate constructs were identified through a medical records database search. Patient-reported outcomes measurement information system Physical Function/Mobility and Pain Interference domain scores were assessed before hemiepiphysiodesis, immediately before hardware removal, and after hardware removal. Radiographs were also assessed at these times to record the zones and angles of deformity and correction. RESULTS: Twenty-eight subjects (53 operative limbs) contributed to the analysis. Mobility and pain interference as measured by the patient-reported outcomes measurement information system were below typical values in a small percentage of the population studied, only 3.6% scored in the moderate and none in the severe categories for both domains. Valgus by radiographic zone was corrected in all patients without significant rebound at follow-up. Compared with preoperative levels, mobility scores improved before hardware removal. Pain Interference scores improved both before hardware removal and at the final follow-up. CONCLUSIONS: Frontal plane knee deformities in the idiopathic population do not cause pain or limit mobility in most subjects. This is critical information, emphasizing that surgical decisions may be made based on the deformity alone, presence of symptoms, and possible future morbidity secondary to valgus deformity. If surgery is postponed because an individual is asymptomatic, the window for correction with guided growth may be lost. Individuals undergoing hemiepiphysiodesis can expect that their pain and function will not be worse during the time that hardware is in place and that surgery is likely to improve any pain they may be experiencing. LEVEL OF EVIDENCE: Level III; retrospective comparative study.

Factors Affecting Rebound Phenomenon After Temporary Hemiepiphysiodesis and Implant Removal for Idiopathic Genu Valgum in Adolescent Patients.

BACKGROUND: The aim of this study was to investigate factors determining postoperative courses, especially focusing on the rebound phenomenon, in adolescent patients with idiopathic genu valgum who underwent temporary hemiepiphysiodesis and implant removal. METHODS: We identified and reviewed patients with idiopathic genu valgum treated with temporary hemiepiphysiodesis [using tension-band plates (plate group, PG) or transphyseal screws (screw group, SG)] and followed-up to skeletal maturity. RESULTS: In our cohort [68 patients and their 68 limbs (randomly selected in bilateral cases)], the mean hip-knee-ankle alignment was -5.4±1.8 degrees at the time of temporary hemiepiphysiodesis (negative means valgus), 2.6±2.1 degrees at the time of implant removal, and 0.7±2.6 degrees at the last follow-up, respectively. Regarding the implants, the correction speed was not significantly different (P=0.192-0.315) between the PG (total 1.29±0.37 degrees/mo, 0.71±0.23 degrees/mo at distal femur, 0.59±0.16 degrees/mo at proximal tibia, n=19) and the SG (total 1.22±0.49 degrees/mo, 0.65±0.25 degrees/mo at distal femur, 0.57±0.23 degrees/mo at proximal tibia, n=49). The magnitude of rebound phenomenon in the PG (4.1±1.9 degrees) was greater (P<0.001) than that in the SG (1.1±3.1 degrees). The use of plates and faster correction speed, rather than more severe preoperative deformity or greater correction angle, were positively associated with the rebound phenomenon in regression analyses. Among the 68 knees, 1 showed valgus alignment ≥5 degrees and 5 showed varus alignment ≥5 degrees at the last follow-up. All the 6 cases were observed in the SG. Surgical wound dehiscence was observed in 1 patient in the PG. CONCLUSIONS: The use of plates and faster correction speed were positively associated with the rebound phenomenon. Careful attention will be needed with the corresponding conditions for optimal results. Progressive genu varum after transphyseal screw removal, which was observed in this study, should be explored in future research. LEVEL OF EVIDENCE: Level III-retrospective comparative series.

Risk Factors for Rebound After Correction of Genu Valgum in Skeletal Dysplasia Patients Treated by Tension Band Plates.

BACKGROUND: Growth modulation using tension band plates (TBPs) is increasingly important for lower limb deformity correction in patients with skeletal dysplasia (SKD). Development of rebound deformity is a concern after TBP removal. Data regarding this complication are rare; therefore, we evaluated the prevalence and risk factors for rebound deformity in children with SKD undergoing correction of genu valgum using TBP. METHODS: All patients with SKD with genu valgum treated by TBP at the distal femur or/and proximal tibia at a single center were reviewed. Inclusion criteria were: (1) minimum 2-year follow-up after TBP removal or having revision surgery for rebound deformity and (2) implant removal age for girls 14 years and below and boys 16 years and below. Exclusion criteria were any femoral/tibial osteotomies during TBP treatment or follow-up. A change of ≥3 degrees of mechanical lateral distal femoral and/or medial proximal tibial angle was accepted as rebound deformity and analyzed statistically. RESULTS: Thirty-three patients (59 limbs; 52 femur and 29 tibia physes) met our criteria. Mean follow-up after implant removal was 43.7 months. Rebound deformities were seen in 43 limbs (39 femurs and 13 tibias). Boys had more rebound than girls; however, this was not influenced by body mass index. Femurs had more rebound than tibias. Patients in the rebound group were younger than the nonrebound group. Time from application to removal of TBP was shorter in the rebound versus nonrebound group. Overcorrected limbs had more rebound deformity than not overcorrected. The difference in growth velocity of lower limbs in the rebound versus nonrebound group was statistically significant. Patients with epiphyseal dysplasia had more rebound than metaphyseal dysplasia, but this was not statistically significant. CONCLUSION: Risk factors for developing a rebound deformity after correction of genu valgum using TBP in SKD included male sex, TBP surgery at a young age, short duration of TBP implantation, overcorrected extremity (mechanical axis deviation ≤1), and high percent growth velocity after TBP removal. LEVEL OF EVIDENCE: Level IV-retrospective study.

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.

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.

Correction of Genu Valgum in Patients With Congenital Fibular Deficiency.

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

Complications After Pediatric ACL Reconstruction: A Meta-analysis.

BACKGROUND: The purpose of this meta-analysis is to review clinical outcomes and complications following pediatric anterior cruciate ligament (ACL) reconstruction. METHODS: The PubMed and EMBASE databases were searched for studies on ACL ruptures in the skeletally immature from 1985 to 2016. Full-text studies in English and performed on humans were included (n=5718). Titles included discussed operative intervention on skeletally immature patients with ACL tears (n=160). Studies that reported rerupture and/or complications with ACL reconstruction specific to the pediatric population, specifically growth disturbance, were then included in a secondary analysis (n=45). Complications not specific to the pediatric population were excluded. Demographics, graft type, surgical technique, follow-up, growth disturbance, rerupture, and patient-reported outcome scores were collected. Data were analyzed in aggregate. RESULTS: In total, 45 studies were included with 1321 patients and 1392 knees. The average age was 13.0 years, 67% were male, and mean follow-up was 49.6 months. There were 115 (8.7%) reruptures in the initial 160 studies reviewed. In total, 94.6% of patients with rerupture required revision ACL surgery. There were 58 total growth disturbances (16 required corrective surgery, or 27.6%). Eighteen knees (3.7%) developed angular deformity, most commonly valgus. There were 37 patients (7.5%) had at least a 1 cm limb-length discrepancy. A total of 23 studies reported International Knee Documentation Committee scores (range, 81 to 100, 88% grade A or B). In total, 20 studies reported excellent Lysholm scores with mean scores of 94.6. CONCLUSIONS: Growth disturbance can occur with any of the reconstruction techniques. Proper surgical technique is likely more important than the specific reconstruction technique utilized. Patients with rerupture require surgery at much higher rates than those with growth disturbance. Although much attention has been focused on growth disturbance, we suggest that equal attention be given to the prevention of rerupture in this age group. LEVEL OF EVIDENCE: Level III.

Idiopathic Genu Valgum and Its Association With Obesity in Children and Adolescents.

BACKGROUND: Obesity as a cause of lower extremity deformity in children has been well established. This deformity is most often seen as tibia vara, however, at our institution we have observed more obese children and adolescents over age 7 years with excessive or progressive idiopathic genu valgum. Our hypothesis is that children with idiopathic genu valgum have high rates of obesity which impact the severity of their disease. METHODS: Retrospective review of existing data was performed on 66 consecutive children/112 limbs over age 7 years with idiopathic genu valgum, seen from 2010 to 2013. Children with known metabolic or skeletal disease were excluded. Genu valgum was defined as mechanical axis in zone II or III and mechanical tibiofemoral angle ≥4 degrees on standing anteroposterior radiograph of the lower extremities. Body mass index (BMI) was calculated and classified by Center for Disease Control percentiles. Skeletal maturation was rated by closure of pelvic and peri-genu physes. Severity of genu valgum was also assessed by femoral and tibial mechanical axes and the mechanical axis deviation. RESULTS: Mean patient age was 12.2±2.2 years. 47% of patients had BMI≥30 and 71% were categorized as obese (>95th percentile). No sex differences were identified. Skeletal maturation explained 25% of the variance in the mechanical axis deviation and 22% of the mechanical tibiofemoral angle. BMI predicted 9.8% of the tibial valgus. Because of its skewed distribution, BMI percentile was a less useful parameter for assessment. CONCLUSIONS: The 71% obesity rate found in our children with idiopathic genu valgum is significantly higher than the normal population. Higher BMI is associated with more tibial valgum but skeletal maturation was the main predictor of overall valgus severity. This suggests that obesity may play a role in the etiology of idiopathic genu valgum which progresses with skeletal maturation, thereby increasing the risk of osteoarthritis in adulthood. LEVEL OF EVIDENCE: Level III.

Clinical and Radiographic Characteristics of Atypical Slipped Capital Femoral Epiphysis.

BACKGROUND: Slipped capital femoral epiphysis (SCFEs) can be idiopathic or atypical (associated with renal failure, radiation therapy, and endocrine disorders). It is important to estimate the likelihood that atypical SCFE shows different clinical and radiographic characteristics and complications with typical SCFEs. METHODS: We retrospectively reviewed 53 patients (66 hips) with SCFEs managed between 1995 and 2016. Sex, age, weight, height, the duration of symptoms the laterality of the slip, and complications were recorded. Bilateral hip and lower extremity long bone radiographs were utilized to record slip angle, genu valgus deformity. Statistical analyses were performed. RESULTS: Among 53 children (32 boys and 21 girls) with 66 SCFEs, 22 children had 29 atypical SCFEs, and 31 children had 38 typical SCFEs. The average age at the time of presentation for the initial SCFEs was 10.9±0.3 years. The average duration of symptoms was 14.1±21.8 weeks. The average Southwick slip angle difference was 23.3±14.8 degrees. There are 43 mild, 13 moderate, and 10 severe SCFEs. 58 were classified as stable, and 8 were unstable. There were significant differences in terms of average age (10.4±2.6 y for atypical SCFEs, 11.2±1.4 for typical SCFEs; P=0.036), average weight (36.2±22.3 kg for patients with atypical slips, compared with 56.9±9.9 kg for those with typical slips; P<0.001), height (132.1±17.6 cm for those with atypical slips, compared with 148.9±12.1 for those with typical slips; P<0.001), and the body mass index (19.4±5.6 kg/cm for those with atypical slips, compared with 25.8±4.6 for those with typical slips; P<0.001). In the group of 22 children with atypical slipped capital epiphysis, there were 19 children with neoplasm (8 neuroblastomas, 3 medulloblastomas, 3 retinoblastomas, 2 ependymomas, 1 craniopharyngioma, 1 Wilms tumor, 1 immature teratoma), 4 children with primary endocrine disorder. We categorized atypical SCFEs in 3 groups by etiology; endocrine disorder-associated (ENDA) SCFEs, chemotherapy-associated (CTA) SCFEs, and radiation therapy-associated (RTA) SCFEs. Subjects of RTA were included if exposed to pelvic irradiation or total body irradiation. There were 4 ENDA, 9 RTA, and 16 CTA. Atypical SCFEs had significantly more valgus slips (P<0.001) and genu valgus deformity (P<0.001) compared with in the group of typical slipped capital epiphysis. Among the group of atypical SCFEs, children with CTA had significantly low body weight, height, and body mass index. CONCLUSIONS: The markedly greater incidence of valgus displacement of proximal femoral epiphysis and genu valgum in childhood cancer survivors with pelvic irradiation and chemotherapy may be associated with atypical SCFE. The authors conclude that in pediatric cancer survivors with hip pain, consideration should be given to atypical SCFE with valgus slip and long-term follow-up of lower extremity alignment. LEVEL OF EVIDENCE: Level III-retrospective comparative study. See instructions for authors for a complete description of levels of evidence.

Concomitant Anterior Cruciate Ligament Reconstruction and Temporary Hemiepiphysiodesis in the Skeletally Immature: A Combined Technique.

BACKGROUND: Young athletes with an anterior cruciate ligament (ACL) disruption and limb malalignment pose a treatment dilemma. Little has been published regarding limb malalignment in this population. Our aim is to review the results of combined treatment of an ACL deficient knee and genu valgum in skeletally immature patients. METHODS: A retrospective review of skeletally immature patients who underwent transphyseal ACL reconstruction and concomitant hemiepiphysiodesis between 2004 and 2015 by 1 surgeon at a single institution was performed. Included patients had at least a year of growth remaining and were followed to skeletal maturity. Patients with a diagnosis of a connective tissue disorder were excluded. Knee stability, rate of retear, the rate of mechanical axis correction, and time to full correction were determined. RESULTS: Ninety skeletally immature patients underwent transphyseal ACL reconstruction, 8 of which met inclusion criteria. Mean time to correction of the valgus deformity was 13 months (0.4 degree/mo). No patient required additional surgeries for malalignment. All patients had improvement in knee stability. One patient had a retear of their ACL reconstruction, for a failure rate of 13%. Preoperative mechanical lateral distal femoral angle and mechanical axis deviation corrected to near-neutral alignment for all treated limbs and were significantly different (P=0.001) than those measured preoperatively. CONCLUSIONS: Promising results were seen for simultaneous correction of genu valgum and transphyseal ACL reconstruction. Treatment of both pathologies in a concomitant surgery can be considered in the appropriate population, with expected results comparable to each procedure in isolation. LEVEL OF EVIDENCE: Level IV-case series.

Risk factors of postoperative valgus malalignment in mobile-bearing medial unicompartmental knee arthroplasty.

OBJECTIVE: The aim of this observational study was to investigate the risk factors of postoperative valgus malalignment after mobile-bearing medial unicompartmental knee arthroplasty (UKA). METHODS: We retrospectively evaluated radiographic and surgical characteristics in 122 consecutive Oxford phase 3 UKAs. According to postoperative hip-knee-ankle angle (HKAA), 24 knees were sorted into group valgus with HKAA > 180° and 98 knees were sorted into group non-valgus with HKAA ≤ 180°. Logistic regression was performed to analyze risk factors including age, gender, BMI, side, preoperative limb alignment HKAA, preoperative LDFA, MPTA, FTFA, thickness of polyethylene bearing insert, tibial prothesis size, femoral prothesis size, medial tibial cut thickness, thickness of distal femoral mill, prothesis angle of coronal, and sagittal plane. RESULTS: The mean mechanical preoperative HKAA of 174.39°±4.23° was corrected to 178.18°±3.49° postoperatively (t = - 13.45, p = 0.000). The mean of postoperative HKAA in valgus group and non-valgus group was 183.45 ± 2.21° and 176.88 ± 2.35°, respectively (t = 12.44, p = 0.000). After statistical analysis with univariate analysis, eight risk factor variables among 16 independent variables were identified as potential predictors with p value ≤ 0.1. Multivariate logistic regression analysis for these eight potential predictors revealed that tibial cut (p = 0.046), LDFA (p = 0.003), MPTA (p = 0.011), and FTFA (p = 0.008) were significant risk factors predicting postoperative valgus malalignment after mobile-bearing UKA. CONCLUSIONS: Preoperative smaller LDFA, FTFA, larger MPTA and less medial tibial cut thickness were significantly associated with postoperative valgus malalignment in mobile-bearing UKA.

Foot and ankle characteristics and dynamic knee valgus in individuals with patellofemoral osteoarthritis.

STUDY DESIGN: Controlled laboratory study; cross-sectional design. BACKGROUND: Foot and ankle characteristics and dynamic knee valgus differ in people with and without patellofemoral (PF) pain. However, it is unknown if these characteristics are evident in people with PF osteoarthritis (OA), compared to pain-free older adults. OBJECTIVES: To compare foot and ankle mobility, foot posture and dynamic knee valgus, measured as the frontal plane projection angle (FPPA) during single-leg squatting, between individuals with and without PFOA. METHODS: Fifty-one participants with PFOA (66% women, mean ± SD age 57 ± 10 years, body mass index (BMI) 27 ± 6 kg/m2), and 23 controls (56% women, age 56 ± 9 years, BMI 24 ± 4 kg/m2) had ankle dorsiflexion measured using the knee-to-wall test, foot mobility calculated as the difference in midfoot height or width between non-weightbearing and weightbearing, and static foot posture characterized utilizing the Foot Posture Index. Peak FPPA was determined from video recordings while participants performed 5 single-leg squats. Linear regressions examined between-groups relationships for foot and ankle characteristics and the FPPA. RESULTS: The PFOA group had less ankle dorsiflexion (odds ratio 6.7, 95% confidence interval 2.46-18.2), greater midfoot height mobility (5.2, 1.78-15.14) and width mobility (4.3, 1.33-14.39), and greater foot mobility magnitude (8.4, 2.32-30.69) than controls. There was no difference in FPPA (knee valgus angle) between groups (15, 0.63-377.99). CONCLUSION: Foot and ankle characteristics were different in individuals with PFOA compared to control participants, however there was no difference in dynamic knee valgus during single leg squat. Clinical interventions to address greater foot mobility may be relevant for PFOA.

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.

Factors affecting femoral rotational angle based on the posterior condylar axis in gap-based navigation-assisted total knee arthroplasty for valgus knee.

BACKGROUND: Achieving proper rotational alignment of the femoral component in total knee arthroplasty (TKA) for valgus knee is challenging because of lateral condylar hypoplasia and lateral cartilage erosion. Gap-based navigation-assisted TKA enables surgeons to determine the angle of femoral component rotation (FCR) based on the posterior condylar axis. This study evaluated the possible factors that affect the rotational alignment of the femoral component based on the posterior condylar axis. MATERIALS AND METHODS: Between 2008 and 2016, 28 knees were enrolled. The dependent variable for this study was FCR based on the posterior condylar axis, which was obtained from the navigation system archives. Multiple regression analysis was conducted to identify factors that might predict FCR, including body mass index (BMI), Kellgren-Lawrence grade (K-L grade), lateral distal femoral angles obtained from the navigation system and radiographs (NaviLDFA, XrayLDFA), hip-knee-ankle (HKA) axis, lateral gap under varus stress (LGVS), medial gap under valgus stress (MGVS), and side-to-side difference (STSD, MGVS - LGVS). RESULTS: The mean FCR was 6.1° ± 2.0°. Of all the potentially predictive factors evaluated in this study, only NaviLDFA (ß = -0.668) and XrayLDFA (ß = -0.714) predicted significantly FCR. CONCLUSIONS: The LDFAs, as determined using radiographs and the navigation system, were both predictive of the rotational alignment of the femoral component based on the posterior condylar axis in gap-based TKA for valgus knee. A 1° increment with NaviLDFA led to a 0.668° decrement in FCR, and a 1° increment with XrayLDFA led to a 0.714° decrement. This suggests that symmetrical lateral condylar hypoplasia of the posterior and distal side occurs in lateral compartment end-stage osteoarthritis with valgus deformity.