Outcome Prediction Model Following Proximal Femoral Osteotomy in Legg-Calvé-Perthes Disease Using Machine Learning Algorithms.

BACKGROUND: The purpose of the current study was (1) to analyze various factors that may be associated with the outcomes of Legg-Calvé-Perthes disease (LCPD), and (2) to develop and internally validate machine learning algorithms capable of providing patient-specific predictions of which patients with LCPD will achieve relevant improvement in radiologic outcomes after proximal femoral varus osteotomy (PFVO). We examined several variables, previously identified as factors, that may influence the outcome of LCPD and developed a machine learning algorithm based on them. METHODS: In this retrospective study, we analyzed patients aged older than  6 years at the time of LCPD diagnosis who underwent PFVO at our institution between 1979 and 2015. Univariate and multivariate logistic regression analyses were used to examine the effects of variables on the sphericity of the femoral head at skeletal maturity, including age at onset, sex, stage at operation, extent of epiphyseal involvement and collapse, presence of specific epiphyseal, metaphyseal, and acetabular changes, and postoperative neck shaft angle (NSA). Recursive feature selection was used to identify the combination of variables from an initial pool of 13 features that optimized the model performance. Five machine learning algorithms [extreme gradient boosting (XGBoost), multilayer perception, support vector machine, elastic-net penalized logistic regression, and random forest) were trained using 5-fold cross-validation 3 times and applied to an independent testing set of patients. RESULTS: Ninety patients with LCPD who underwent PFVO were included in this study. The mean age at diagnosis was 7.93 (range, 6.0 to 12.33) years. The average follow-up period was 10.11 (range, 5.25 to 22.92) years. A combination of 8 variables, optimized algorithm performance, and specific cutoffs were found to decrease the likelihood of achieving the 1 or 2 Stulberg classification: age at onset ≤ 8.06, lateral classification ≤ B, 12.40 < preoperative migration percentage (MP) ≤ 22.85, Catterall classification ≤ 2, 117.4 < postoperative NSA ≤ 122.90, -10.8 < postoperative MP ≤ 6.5, 139.65 < preoperative NSA ≤ 144.67, and operation at stage 1. The XGBoost model demonstrated the best performance (F1 score: 0.78; area under the curve: 0.84). CONCLUSIONS: The XGBoost machine learning algorithm achieved the best performance in predicting the postoperative radiologic outcomes in patients with LCPD who underwent PFVO. In our population, age at onset ≤ 8.06, lateral classification ≤ B, 12.40 < preoperative MP ≤ 22.85, Catterall classification ≤ 2, 117.4 < postoperative NSA ≤ 122.90, -10.8 < postoperative MP ≤ 6.5, 139.65 < preoperative NSA ≤ 144.67, and operation at an early stage had the likelihood of achieving the spherical femoral head for the patients with LCPD that underwent PFVO. After external validation, the online application of this model may enhance shared decision-making. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Effect of Postoperative Femoral Neck Shaft Angle on Femoral Head Sphericity Following Proximal Femoral Osteotomy in Legg-Calve-Perthes Disease.

BACKGROUND: Herein, we aimed to examine the relationship between the postoperative neck shaft angle (NSA) and the Stulberg outcome at skeletal maturity in patients with Legg-Calvé-Perthes disease (LCPD) who underwent proximal femoral varus osteotomy (PFVO) and to determine the optimal angle of varization. METHODS: In this retrospective study, we analyzed the data of 90 patients aged older than 6 years at the time of diagnosis with LCPD who underwent PFVO at our institution between 1979 and 2014. Univariate and multivariate logistic regression analyses were used to examine the effects of variables on the sphericity of the femoral head at skeletal maturity, including the age at onset, sex, stage at operation, extent of epiphyseal involvement and epiphyseal collapse, presence of specific epiphyseal, metaphyseal, and acetabular changes, and postoperative NSA. The sphericity of the femoral head on the final plain follow-up radiographs of the hip joint at skeletal maturity was assessed using the Stulberg classification. Cases of spherical femoral head (Stulberg I or II) were rated as good, whereas those of ovoid or flat femoral head (Stulberg III, IV, or V) were rated as bad. RESULTS: The mean age at diagnosis was 7.93 (range, 6.0-12.33) years. The average follow-up period was 10.11 (range, 5.25-22.92) years. The pre and postoperative mean NSAs were 137.31±6.86 degrees (range, 115.7-158 degrees) and 115.7±9.83 degrees (range, 88.6-137.6 degrees), respectively. The age at diagnosis, lateral pillar classification, and postoperative NSA were found to be closely related to the sphericity of the femoral head at skeletal maturity. Patients with a postoperative NSA of <105 degree or more than 125 degree were less likely to have a spherical femoral head. CONCLUSIONS: Our study showed that patients with a postoperative NSA between 105 and 125 degrees were more likely to have a spherical femoral head. When performing PFVO in patients with LCPD, reasonable varus angulation of PFVO should be taken into consideration for the success of the operation. LEVEL OF EVIDENCE: Level III retrospective cohort study.

Characteristics of hip impingement syndrome in patients with multiple hereditary exostoses.

BACKGROUNDS: This study aimed to investigate the characteristic deformities of the hip in multiple hereditary exostoses patients (MHE) and its association with the hip impingement syndrome. MATERIALS AND METHODS: Between 2001 and 2019, total 51 patients (102 hips) were evaluated in this study. Patients with MHE were classified to femoro-acetabular impingement (FAI) symptom group, ischio-femoral impingement (IFI) symptom group and non-impingement symptom group by comparing the symptoms, clinical signs and imaging studies. To assess the morphometry of the hip in patients with MHE, the femoral neck-shaft angle, Sharp's acetabular angle and center-edge (CE) angle were evaluated. Alpha angle was further evaluated to investigate the FAI using radiographs, and the minimum ischio-femoral distance was further measured to investigate the IFI using computed-tomographic (CT) study. RESULTS: On hip impingement symptom analysis, FAI symptom and IFI symptom were confirmed in 14 hip joints and 18 hip joints, respectively. Unlike general population, the number of the hip with IFI-symptom was higher than those with FAI symptom in this study. In morphometric evaluation of MHE hips, coxa valga was most prominent deformity with occasional tendency of mild acetabular dysplasia. In a comparison of morphometric study between the impingement symptom group and non-symptom group, the FAI symptom showed significant differences of morphometric measure values than those of the non-symptom group (FAI symptom group vs. Non-FAI symptom group; Femoral neck-shaft angle (153.9 vs 142.6), Sharp's angle (45.0 vs 41.5), CE angle (21.1 vs 28.8) and alpha angle (76.7 vs 57.9)). Similarly, the IFI symptom group also showed significant differences of morphometric measure values than those of the non-symptom group (IFI-symptom vs. Non-IFI symptom; Femoral neck-shaft angle (150.9 vs 142.7), Sharp's angle (44.7 vs 41.4), CE angle (21.1 vs 29.3) and alpha angle (73.3 vs 56.8)). In addition, the minimum ischio-femoral distance measured using CT was significantly decreased in the IFI symptom group (IFI symptom group: 6.6, Non-IFI symptom group: 16.4). CONCLUSION: The results suggest that the characteristic deformities represented by coxa valga in the MHE hip act as an offset for FAI symptoms, on the contrary, act as a trigger for IFI symptoms. LEVEL OF EVIDENCE: Level III.

Results of Early Proximal Femoral Osteotomy at Skeletal Maturity in Legg-Calvé-Perthes Disease: Implication for the Bypass of Fragmentation Stage.

BACKGROUND: The aim was to assess the long-term radiographic outcomes of patients with Legg-Calvé-Perthes disease following an early proximal femoral osteotomy (PFO) performed in avascular necrosis stage or early fragmentation stage. METHODS: In this retrospective study, we analyzed data of 65 patients aged above 6 years at the time of diagnosis with unilateral Legg-Calvé-Perthes disease, following early PFO performed at our institution between 1979 and 2013. We observed the presence of bypassing fragmentation stage, which was classified into complete and incomplete. We compared radiographic outcomes between patients with bypass of fragmentation stage (26 hips) and those without (31 hips). Regarding skeletal maturity, the hips were graded according to the femoral head shapes: spherical, ovoid, or flat. RESULTS: The mean age at diagnosis was 7.9 years (range: 6.0 to 11.9 y). The average follow-up period was 11.8 years (range: 5.9 to 22.9 y). Fragmentation bypass occurred in 40.5% (26/65) of patients, with 8 (12.3%) "undetermined" cases. Patients who completely or partially bypassed fragmentation experienced significantly less severe lateral pillar collapse (P=0.016). The femoral head was also significantly more spherical in patients with bypass (P=0.024). CONCLUSIONS: Our results show that 40.5% of patients who underwent early PFO bypassed the fragmentation stage. The degree of lateral pillar collapse was lower in patients with bypass. In addition, there were significantly more patients with more spherical femoral head in the bypass group. LEVEL OF EVIDENCE: Level IV-case series.

Clinical analysis of patients with skeletal metastasis of lung cancer.

BACKGROUND: Many factors influence bone metastases of lung cancer, and several studies report about survival of skeletal metastasis. However, few studies have focused on identifying the prognostic factors for skeletal metastasis of lung cancer, especially following orthopedic surgery. We conducted a retrospective analysis of the clinical characteristics of skeletal metastasis from lung cancer and discuss the prognostic factors. METHODS: We performed a medical record review of 202 patients who were diagnosed with skeletal metastasis from lung cancer. Adenocarcinoma was found in 116 patients (57.4%), squamous cell carcinoma in 29 (14.4%), small-cell lung cancer (SCLC) in 37 (18.7%), and large-cell carcinoma and other types of cancer in 20 patients (9.9%). Orthopedic surgery for skeletal metastasis was performed in 41 patients (20.3%). RESULTS: Lung cancer survival was 12.1 months. After diagnosis of lung cancer, skeletal metastasis was found at a mean of 2.5 months, and skeletal metastasis survival was 9.8 months. Lung cancer survival in patients younger than 60 years was 13.8 months, and lung cancer survival in patients 60 years or older was 10.8 months (p = 0.009). Skeletal metastasis survival in patients younger than 60 years was 11.0 months, and skeletal metastasis survival in patients 60 years or older was 8.8 months (p = 0.002). Mean skeletal metastasis survival with surgery was 12.6 months and without surgery was 9.1 months (p < 0.000). In the multivariate analysis of lung cancer survival, age under 60 years [HR (95% CI) 1.549 (1.122-2.139), p = 0.008], non-small cell lung cancer pathology type [HR (95% CI) 1.711 (1.157-2.532), p = 0.008], chemotherapy for skeletal metastasis [HR (95% CI) 8.064 (3.981-16.332), p < 0.000], and radiation therapy for skeletal metastasis [HR (95% CI) 1.791 (1.170-2.742), p = 0.007] were significant, independent, good prognostic factors. In the multivariate analysis of skeletal metastasis survival, age under 60 years [HR (95% CI) 1.549 (1.124-2.134), p = 0.007], non-small cell lung cancer pathology type [HR (95% CI) 2.045 (1.373-3.047), p < 0.000], chemotherapy for skeletal metastasis [HR (95% CI) 7.121 (3.542-14.317), p < 0.000], and orthopedic surgical treatment for skeletal metastasis [HR (95% CI) 1.710 (1.148-2.547), p = 0.008] were significant, independent, good prognostic factors. CONCLUSIONS: Patients who survived longer were less than 60 years old, received chemotherapy as treatment for skeletal metastasis, had NSCLC rather than SCLC, and underwent orthopedic surgery for skeletal metastasis.

A cellular blue nevus with pigmented epithelioid melanocytoma-like pattern on the ipsilateral upper arm associated with a congenital plaque-type blue nevus on the hand.

A 36-year-old man presented with a subcutaneous nodule on the right upper arm. A small nodule had developed 8 years earlier, and grew in size, accompanied by a tingling sensation and numbness. In addition, he had a bluish irregular patch on the right hand since birth, which crossed from the palm to the dorsal hand. Skin biopsies from the hand showed a heavily pigmented melanocyte proliferation in the dermis with perieccrine, perivascular, and perineural involvement, and a diagnosis of congenital plaque-type blue nevus was made. The tumor on the arm was located closely along the median nerve, and was observed as a large black pedunculated round tumor. Histopathologically, the tumor on the arm consisted of densely packed tissue with nevoid cells without atypia in the larger nodular part, and heavily pigmented spindle and epithelioid melanocytes in the slender stalk area, which was diagnosed as cellular blue nevus with pigmented epithelioid melanocytoma-like pattern. Next-generation sequencing revealed GNAQ mutations in the hand lesion, and in the lesions on the arm. This case suggests that the areas of skin following the same neural distribution of a congenital plaque-type blue nevus on the extremities should be followed up for secondary changes.

Coronal malalignment of lower legs depending on the locations of the exostoses in patients with multiple hereditary exostoses.

BACKGROUNDS: Though malalignment of lower legs is a common pathologic phenomenon in multiple hereditary exostoses (MHE), relationship between locations of exostoses and malalignment of lower legs remains unclear. This study examined radiographs of MHE patients in an attempt to evaluate the tendency of coronal malalignment of lower legs with different location of exostoses on lower legs consisting of two parallel long bones. METHODS: Between 2000 and 2017, we retrospectively reviewed the anteroposterior films of the teleo-roentgenographics of 63 patients with MHE. The patients were classified into four different groups depending on the locations of the exostosis, which occurred on both proximal and distal tibiofibular joints (A), proximal tibiofibular joint (B), distal tibiofibular joint (C), and not for the tibiofibular joint area (D). To evaluate the influence of the location of exostoses on coronal malalignment of lower legs, medial proximal tibia angle (MPTA), lateral distal tibia angle (LDTA), and fibular shortening were analyzed for each group. RESULTS: Significant difference was observed in multiple comparative analyses for each of the four groups. On MPTA radiologic analysis, group A showed greatest value with significant difference compared with groups C and D (vs. (B): p = 0.215; vs. distal joints (C): p = 0.004; vs. (D): p = 0.001). Group B showed significant difference only with group D (vs. distal joints (C): p = 0.388; vs. (D): p = 0.002), but for group C and D showed no significant difference. For LDTA, only group A showed significant difference compared to other groups (p < 0.001). With regard to tibiofibular ratio for evaluation of fibular shortening, group A showed the lowest ratio (vs. (B): p = 0.004; vs. (C): p = 0.655; vs. (D): p < 0.001). Group C also presented the significant lower ratio than group D (p = 0.002). CONCLUSIONS: For evaluation of the coronal malalignment of lower legs in MHE patients, not only ankle around the distal tibiofibular joint but also proximal tibiofibular joint should be examined, in that, lower limb deformity occurred by two parallel long bone which has self-contained joint. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Prognostic implications of polycomb proteins ezh2, suz12, and eed1 and histone modification by H3K27me3 in sarcoma.

BACKGROUND: Polycomb repressive complex 2 (PRC2; formed by EZH2, SUZ12, and EED protein subunits) and PRC1 (BMI1 protein) induce gene silencing through histone modification by H3K27me3. In the present study, we characterized the PRC expression pattern and its clinical implication in sarcoma. METHODS: Using immunohistochemistry, we analyzed PRC expression in 105 sarcoma patients with 5 subtypes: synovial sarcoma (n = 18), rhabdomyosarcoma (n = 28), Ewing sarcoma (n = 15), osteosarcoma (n = 30), and others (n = 14). RESULTS: The median age at diagnosis in the patient cohort was 26.8 years (range: 1-78 years) and the male-to-female ratio was 1:4. Initial disease presentation was locoregional disease in 83% of patients and initial metastatic disease in the remaining 17%. PRC expression was not significantly different according to histologic subtype (P = 0.400). Overall survival (OS) was significantly poor for SUZ12 high (P = 0.001), EED1 high (P = 0.279), and H3K27me3 high (P = 0.009). Ultimately, patients with PRC2high had significantly inferior OS than the no expression group (P = 0.009). In the Cox proportional hazard model adjusted for stage, histologic grade, surgery, margin and initial metastasis, SUZ12 expression (P = 0.020, HR 29.069, 95% CI 1.690-500.007), H3K27me3 (P = 0.010, HR 3.743, 95% CI 1.370-10.228) expression was significantly associated with shorter OS. CONCLUSION: We detected PRC expression in various sarcomas and demonstrated its independent negative prognostic role, suggesting the PRC axis as promising therapeutic target for treating sarcoma.

Novel NTRK1 mutations associated with congenital insensitivity to pain with anhidrosis verified by functional studies.

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV, features loss of pain sensation, decreased or absent sweating (anhidrosis), recurrent episodes of unexplained fever, self-mutilating behavior, and variable mental retardation. Mutations in neurotrophic receptor tyrosine kinase 1 (NTRK1) have been reported to be associated with CIPA. We identified four novel NTRK1 mutations in six Korean patients from four unrelated families. Of the four mutations, we demonstrated using a splicing assay that IVS14+3A>T causes aberrant splicing of NTRK1 mRNA, leading to introduction of a premature termination codon. An NTRK1 autophosphorylation assay showed that c.1786G>A (p.Asp596Asn) abolished autophosphorylation of NTRK1. In addition, Western blotting showed that c.704C>G (p.Ser235*) and c.2350_2363del (p.Leu784Serfs*79) blunted NTRK1 expression to undetectable levels. The four novel NTRK1 mutations we report here will expand the repertoire of NTRK1 mutations in CIPA patients, and further our understanding of CIPA pathogenesis.

An Evaluation of Forearm Deformities in Hereditary Multiple Exostoses: Factors Associated With Radial Head Dislocation and Comprehensive Classification.

PURPOSE: This study attempted to evaluate a series of patients with hereditary multiple exostoses (HME) who could not be categorized according to the widely accepted Masada classification and to identify radiographic variables such as radial bowing, ulnar shortening, ulnar variance, radial articular angle, and carpal slip predictive of deformity. METHODS: We retrospectively reviewed data on 102 upper limbs of 53 pediatric patients with HME. Demographics, site of forearm involvement, and radiographic parameters were documented. Patients with exostoses of the forearms were categorized into 6 groups based on location of the exostoses and presence or absence of a dislocated radial head. Proportional ulnar shortening was calculated as the ratio of ulnar length to radial length. RESULTS: According to the Masada classification, 4 limbs were normal, 10 were type I, 2 were type II, and 24 were type III. Sixty-six limbs were unclassifiable. We classified those 66 limbs using a modification of the Masada classification. Of the 106 limbs, 11 (10.3%) had a dislocated radial head. Based on the radiographic analysis, patients with proportional ulnar shortening of less than 0.9 had a higher risk of radial head dislocation than did those with proportional ulnar shortening of 0.9 or greater. Patients with radial bowing greater than 8.1% showed a higher frequency of radial head dislocation than did those with radial bowing of 8.1% or less. Exostoses of both the distal radius and ulna tended to increase the rate of radial head dislocation. A greater amount of negative ulnar variance caused more radial bowing and a greater radioarticular angle. CONCLUSIONS: We propose a new comprehensive forearm classification for patients with HME. Proportional ulnar shortening less than 0.9 and radial bowing 8.1% or greater can be used to predict the risk of radial head dislocation. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Posttraumatic Tibiofibular Synostosis After Treatment of Distal Tibiofibular Fractures in Children.

INTRODUCTION: Posttraumatic pediatric distal tibiofibular synostosis is a rare complication following fracture. This is a retrospective, multicenter case series of synostosis of distal tibiofibular fractures in children. The purpose was to evaluate the incidence and pattern of posttraumatic distal tibiofibular synostosis in children. METHODS: Of the 604 pediatric distal tibiofibular fractures, 20 patients (3.3%) with synostosis after treatment of distal tibiofibular fractures were identified at 3 tertiary referral centers. There were 12 boys and 8 girls, with a mean age of 8.4±2.0 years (range, 3.7 to 11.5 y) at the time of injury. Medical records were reviewed, and serial radiographs were analyzed to determine fracture configuration, pattern of synostosis, and changes in the relative positions of the proximal and distal tibial and fibular physes and in the alignment of the ankle. RESULTS: The time from the occurrence of fracture until the recognition of the synostosis ranged from 2 to 6 months (mean, 2.8 mo). The most common fracture configuration was oblique tibial fracture combined with comminuted fibular fracture. There were 12 focal types and 8 extensive types. The proximal tibiofibular distance was decreased in 13 patients. Proximal migration of the distal fibular physis developed in all cases. Five patients exhibited ankle valgus of 10 degrees or greater with moderate or severe distal fibular shortening. Eight patients were symptomatic after synostosis and 12 patients were asymptomatic. CONCLUSIONS: We identified 2 patterns of synostosis after the treatment of pediatric distal tibiofibular fracture: focal and extensive. The focal type was more prevalent than the extensive type, which was more likely to occur due to high-energy injury. When a tibiofibular cross-union develops, it creates growth abnormalities that warrant observation and potential treatment, as it may lead to progressive deformity or ankle pain. LEVEL OF EVIDENCE: Level IV.

Developmental pattern of the hip in patients with hereditary multiple exostoses.

BACKGROUND: Coxa valga is a common clinical feature of hereditary multiple exostoses (HME). The current study aimed to determine the unique developmental pattern of the hip in patients with HME and evaluate the factors that influence its progression. METHODS: Thirty patients (57 hips) with HME were divided into two groups according to the Hilgenreiner epiphyseal angle (HEA). Twenty-two patients (44 hips) including 13 men and 9 women were assigned to group 1 (HEA <25°), and 8 patients (13 hips) including 3 men and 5 women were assigned to group 2 (HEA ≥25°). The mean age at the initial presentation was 6.0 (4-12) years with 6.8 (4-11) years of follow-up in group 1, and 10.4 (8-13) years with 5.4 (2-9) years of follow-up in group 2. We measured the HEA, neck-shaft angle (NSA), acetabular index (AI), center-edge angle (CEA), and migration percentage (MP) for radiographic evaluation. RESULTS: Among the hips, 50 (87.7%) hips had coxa valga and 27 (47.4%) hips had abnormal MP (42.1% were borderline and 5.3% were subluxated). There was a significant difference in the HEA and NSA between the groups (p < 0.001 and p < 0.05, respectively). The HEA significantly correlated with the development of the NSA and no correlation was found between the HEA and AI, CEA, and MP. CONCLUSIONS: There was a significant relationship between the HEA at the initial presentation and the NSA at skeletal maturity. We should consider guided growth for patients with lower HEA to prevent significant coxa valga deformity with close follow-up.

Anterior translation and rotational stability of anterior cruciate ligament-deficient knees during walking: speed and turning direction.

BACKGROUND: Anterior cruciate ligament (ACL) rupture is one of the most common injuries associated with the knee. After ACL injury, knee joint stability can be altered, resulting in abnormal loading during functional activities. Since ACL-deficient (ACLD) knees are also vulnerable to translational and rotational instability, patients need to be wary of certain motions encountered in daily life. The present study investigated the effect of walking speed and pivoting directional change during gait on knee joint kinematics of ACLD knees. We hypothesized that faster walking and crossover turning would induce severe kinematic changes. METHODS: Thirty-five patients (22 males and 13 females) having a unilateral isolated subacute ACLD knee (from 1 to 3 months after injury) and contralateral intact (CLI) knee participated in this study. Spatiotemporal parameters, three-dimensional (3D) knee joint angles, and anterior-posterior (AP) translation were obtained by a 3D high-speed motion-capturing system. The CLI knee of each patient served as the control. The calculated AP stability and knee joint angles were used to test the research hypothesis. Mixed two-way repeated measures analysis of variance was performed to clarify the effects of walking speed and pivoting direction with a significance of 0.05. When a significance of mean comparison was detected, a post hoc test was performed. RESULTS: Significant and consistent increased AP translation of the tibia relative to the femur at the whole stance phase of the gait cycle was evident in ACLD knees compared to CLI knees for normal and faster (20 % greater than normal) walking speeds. Faster walking speed did not induce significantly more anterior location of the tibia. In addition, ACLD knees were significantly less extended than CLI knees during a large portion of midstance. Although there was a consistent varus offset between the curves of ACLD and CLI knees, the difference did not reach statistical significance during the stance phase. Also, ACLD knees did not show any significant difference in tibial rotation compared to CLI knees during the entire stance phase of the gait cycle. For pivoting turns, ACLD knees showed significantly less extended and varus offset than CLI knees only during the cutting turn. ACLD knees exhibited less tibial internal rotation during the crossover turn and less tibial external rotation during the cutting turn than CLI knees. CONCLUSIONS: In ACLD knees, the tibia tended to shift more anteriorly and changed with less extension at walking. However, faster walking speed did not induce any significant difference compared with normal-speed walking. In addition, ACLD knees displayed kinematic changes during pivoting, but not the crossover turn.

Minimally invasive surgical technique for unstable supracondylar humerus fractures in children (Gartland type III or IV).

Background: Achieving and maintaining anatomical reduction during the treatment of pediatric humerus fractures, classified as Gartland type III or IV, presents a clinical challenge. Herein, we present a minimally invasive surgical approach using a novel and simple K-wire push technique that aids in achieving and maintaining anatomical reduction. Methods: We reviewed data of children receiving treatment for supracondylar fractures of the humerus at our hospital between January 2016 and December 2020. Patients were divided into two groups based on the method of treatment: Group 1 was treated with the K-wire push technique, and Group 2 was treated with the standard technique as described by Rockwood and Wilkins. The medical records and radiographic images were reviewed. In total, 91 patients with Gartland types III and IV fractures were included, with 37 and 54 patients in Groups 1 and 2, respectively. Results: The postoperative reduction radiographic parameters and Flynn scores at final follow-up were not significantly different between the two groups. Conclusion: The minimally invasive K-wire push technique for unstable supracondylar fractures in children is a safe and effective alternative for improving reduction. Using this technique, complications can be minimized, and the requirement for open reduction can be reduced.

Toe component excision in postaxial polydactyly of the foot.

BACKGROUND: Polydactyly of the fifth toe is the most common congenital malformation of the forefoot, and no consensus has been reached as to which toe component should be excised or by which surgical technique. The purpose of this study was to evaluate the results of the operative treatment of postaxial polydactyly and to offer treatment guidelines. METHOD: We retrospectively reviewed the details of 27 patients with postaxial polydactyly (36 feet) treated from September 2004 to March 2010. To select the dominant toe of postaxial polydactyly, we evaluated the morphological and radiological configurations. To excise the medial toe, we treated the polydactyly by dorsal rectangular flap and a full-thickness inguinal skin graft. To excise the lateral toe, we treated the polydactyly by racket-shape incision. Patient satisfaction indices were evaluated on the basis of responses to the PSQ-10 patient satisfaction questionnaire and clinical outcomes. RESULT: Overall surgical outcomes were satisfactory with the exception of 2 cases of skin graft problems. Eighteen of the 36 reconstructed toes were smaller than the normal toes, but valgus deformity was observed in only 3 cases. CONCLUSION: The described medial toe excision technique and the devised toe selection algorithm were able to satisfy functional and cosmetic requirements.

New posterior column reconstruction using titanium lamina mesh after total en bloc spondylectomy of spinal tumour.

PURPOSE: To investigate the usefulness of titanium lamina mesh for posterior column reconstruction after total en bloc spondylectomy in patients with spinal tumour and evaluate the radiographic outcomes of this method. METHOD: Eight patients who underwent total en bloc spondylectomy with posterior column reconstruction using titanium lamina mesh and bone graft to treat a spinal tumour were included in this study. The mean age at the time of surgery was 50.6 years (range, 16.5-70.9 years) and the mean follow-up duration was 50.2 months (range, 28.1-68.7 months). The pathological lesions were located from the T2 to L1 vertebrae. There were four patients in each primary and metastatic tumour group. For the posterior column reconstruction, titanium lamina mesh was used and bone graft was applied over the lamina mesh. Radiographic evaluation was used to investigate the displacement of lamina mesh and union of the grafted bone above lamina mesh. RESULTS: At the postoperative six month follow-up, a bony bridge on the titanium mesh between upper and lower adjacent lamina was observed in all cases, except for one with infection. On the last follow-up, there was no collapse or displacement of titanium lamina mesh, and there was no instability or malalignment of the spinal column. CONCLUSIONS: Posterior column reconstruction using titanium lamina mesh during total en bloc spondylectomy for spinal tumour was a useful surgical option that provided new lamina reconstruction for stability of spinal column and protection of the neural elements.

Treatment of bilateral congenital extensor tendon dislocation on multiple digits with only one sagittal band reconstruction: a case report.

Bilateral congenital dislocation of the extensor tendon in the metacarpophalangeal joint is an exceedingly rare disease and often involves multiple fingers. Surgical treatment of multiple congenital extensor tendon dislocations in both hands has been reported; however, no report has clearly stated whether all fingers should be surgically treated in patients with multiple finger involvement. We report a case in which we successfully treated bilateral congenital extensor tendon dislocation on multiple digits with only one single-loop reconstruction of the sagittal band instead of operating on all involved fingers.

Relationship between Slip Severity and BMI in Patients with Slipped Capital Femoral Epiphysis Treated with In Situ Screw Fixation.

Background: Slipped capital femoral epiphysis (SCFE) is a hip disorder that occurs in adolescence before epiphyseal plate closure, causing anatomical changes in the femoral head. Obesity is known to be the single most important risk factor for idiopathic slipped capital femoral epiphysis (SCFE), which is highly related to mechanical factors. Meanwhile, as increased slip angle increases major complications in patients with SCFE, slip severity is an important factor to evaluate prognosis. In obese patients with SCFE, higher shear stress is loaded on the joint, which increases the likelihood of slip. The study aim was to assess the patients with SCFE treated with in situ screw fixation according to the degree of the obesity and to find any factors affecting the severity of slip. Methods: Overall, 68 patients (74 hips) with SCFE who were treated with in situ fixation screw fixation were included (mean age 11.38, range: 6-16) years. There were 53 males (77.9%) and 15 females (22.1%). Patients were categorized underweight, normal weight, overweight, and obese depending on BMI percentile for age. We determined slip severity of patients using the Southwick angle. The slip severity was defined as mild if the angle difference was less than 30 degrees, moderate if the angle difference was between 30 and 50 degrees, and severe if the angle difference was greater than 50 degrees. To examine the effects of several variables on slip severity, we used a univariable and multivariate regression analysis. The following data were analyzed: age at surgery, sex, BMI, symptom duration before diagnosis (acute, chronic, and acute on chronic), stability, and ability to ambulate at the time of the hospital visit. Results: The mean BMI was 25.18 (range: 14.7-33.4) kg/m2. There were more patients with overweight and obese than those with normal weight in SCFE (81.1% vs. 18.9%). We did not find significant differences between overall slip severity and degree of obesity or in any subgroup analysis. Conclusions: We did not find a relationship between slip severity and degree of obesity. A prospective study related to the mechanical factors affecting the slip severity according to the degree of obesity is needed.

Outcomes of proximal chevron osteotomy for moderate versus severe hallux valgus deformities.

BACKGROUND: Proximal chevron osteotomy with a distal soft tissue procedure has been widely used to treat moderate to severe hallux valgus deformities. However, there have been no studies comparing the results of proximal chevron osteotomy between patients with moderate and severe hallux valgus. We compared the results of this procedure among these groups. METHODS: A retrospective review of 95 patients (108 feet) that underwent proximal chevron osteotomy and distal soft tissue procedure for moderate and severe hallux valgus was conducted. The 108 feet were divided into two groups: moderate hallux valgus (Group A) and severe hallux valgus (Group B). Group A was composed of 57 feet (52 patients) and Group B of 51 feet (43 patients). Average followup was 45 months. RESULTS: Mean American Orthopedic Foot and Ankle Society hallux metatarsophalangeal-interphalangeal scores were 54.1 points in Group A and 53.0 points in Group B preoperatively, and these improved to 90.8 and 92.6, respectively, at the last followup. Mean hallux valgus angles in Groups A and B reduced from 32.3 and 40.8 degrees, preoperatively to 10.7 and 13.2 degrees, postoperatively. Similarly, mean first intermetatarsal angles in Groups A and B reduced from 15.0 and 19.2 degrees, preoperatively to 9.0 and 9.2 degrees, postoperatively. CONCLUSION: The clinical and radiographic outcomes of proximal chevron osteotomy with a distal soft tissue procedure were found to be comparable for moderate and severe hallux valgus. Accordingly, our results suggest that this procedure provides an effective and reliable means of correcting hallux valgus regardless of severity of deformity.

A Genotype-Phenotype Study of Multiple Hereditary Exostoses in Forty-Three Patients.

Multiple hereditary exostoses (MHE) is a rare autosomal dominant skeletal disorder with a variety of clinical manifestations. We aimed to evaluate the general clinical phenotypic severity of MHE using our own scoring system and analyzed the risk factors associated with severe clinical phenotypes. In this study, 43 patients from 30 families were analyzed. The mutations were identified by direct sequencing of polymerase chain reaction-amplified genomic DNA or by multiplex ligation-dependent probe amplification. According to a new scoring system devised by the authors, the severity of the phenotype was assessed as mild, moderate, or severe based on the deformity of each segment, number of exostoses, leg length discrepancy, and functional limitations. Of 43 patients from 30 families, 39 patients (90.7%) and 24 families (80%) presented with EXT1 or EXT2 mutations. Patients with EXT1 mutations had a significantly worse phenotype than that of patients with EXT2 mutations or without any detectable mutation. The mean clinical score of patients with an EXT1 mutation (5.76; range, 2.0-8.0; SD = 1.60) was higher than that of patients with an EXT2 mutation (4.06; range, 2.0-7.0; SD = 1.47) or of those without any detectable mutation (4.63; range, 3.0-6.0; SD = 1.44; p = 0.005). According to our classification system, more patients with EXT1 mutations had 'severe disease' than those with EXT2 mutations. Deformity scores were also higher in patients with EXT1 mutations (p = 0.018). In the multivariate analysis, the deformity score was found to be associated with the 'severe' class (p = 0.031). In conclusion, 90.7% of patients with MHE showed EXT mutations. Our scoring system showed reliable results. We suggest that the extent of deformity is an important factor in determining the phenotype of MHE and close monitoring for the development of severe disease is recommended in patients with high deformity scores.