Long-term outcome of total hip arthroplasty in patients with multiple hereditary exostosis.

BACKGROUND: Multiple hereditary exostosis (MHE) is a rare autosomal dominant disorder characterized by multiple osteochondromas. There is a paucity of literature concerning total hip arthroplasty (THA) in patients with MHE. The aim of this study is to report long-term outcomes of THA in patients with MHE. METHODS: Fourteen patients undergoing 15 THA's for the treatment of osteoarthritis in the presence of osteochondromas and proximal femoral deformity secondary to MHE were reviewed. Mean age at the time of surgery and follow-up was 56 and 12 years. Seven (47%) had uncemented femoral components. Eleven hips had coxa valga on preoperative imaging. Clinical outcomes were assessed with both Harris hip scores (HHS) and Musculoskeletal Tumor Society Scores (MSTS). RESULTS: Following surgery, there was an improvement in the HHS (48-82, p < 0.01) and MSTS scores (41-70%, p < 0.01). Complications occurred in 5 patients leading to reoperation in 3 patients, of which 2 patients underwent a revision procedure at 19 and 20-years postoperative. The 10-year revision free survival was 100%. CONCLUSIONS: THA in the setting of MHE reliably improves patient function. One in three patients will have a postoperative complication; however, the long-term incidence of revision is low.

Guided Growth Improves Coxa Valga and Hip Subluxation in Children With Hereditary Multiple Exostoses.

BACKGROUND: In children with severe hereditary multiple exostoses (HME), coxa valga, and hip subluxation are common deformities. The literatures related to surgical management and prevention of hip joint subluxation in HME are scarce. In this study, we aimed to investigate the efficacy of guided growth procedure to correct coxa valga and hip subluxation in HME patients. METHODS: We retrospectively retrieved 12 patients who received guided growth procedures for coxa valga and hip subluxation in HME patients with proximal femur exostoses with a minimum follow-up time of 2 years between 2012 and 2019. Radiographic parameters include head-shaft angle, Hilgenreiner-epiphyseal angle, acetabular index, Reimer migration percentage, center-edged angle, articulo-trochanteric distance, and femoral neck length for comparison between preoperative and latest follow-up results. It was conducted statistically by paired t test and Wilcoxon signed rank test. RESULTS: In this study, the mean difference between preoperative and latest follow-up was significant in head-shaft angle (12±5 degrees; CI, 10-14; P<0.001), Hilgenreiner-epiphyseal angle (12±5 degrees; CI, 10-15; P<0.001), and MP (7%±8%; CI, 3-11; P=0.001). There was a low revision rate (4 of 21, 19%) and no complication in our study. Compared with previous studies on guided growth in children with cerebral palsy and developmental dysplasia of the hip, our study showed good comparable outcomes. CONCLUSION: The results indicated that guided growth improves the hip radiographic parameters of children with HME and may prevent coxa valga and hip subluxations. It is a safe procedure and provides predictable results. LEVEL OF EVIDENCE: Level IV; therapeutic, case series.

Does screw position matter for guided growth in cerebral palsy hips?

AIMS: Guided growth has been used to treat coxa valga for cerebral palsy (CP) children. However, there has been no study on the optimal position of screw application. In this paper we have investigated the influence of screw position on the outcomes of guided growth. METHODS: We retrospectively analyzed 61 hips in 32 CP children who underwent proximal femoral hemi epiphysiodesis between July 2012 and September 2017. The hips were divided into two groups according to the transphyseal position of the screw in the coronal plane: across medial quarter (Group 1) or middle quarter (Group 2) of the medial half of the physis. We compared pre- and postoperative radiographs in head-shaft angle (HSA), Reimer's migration percentage (MP), acetabular index (AI), and femoral anteversion angle (FAVA), as well as incidences of the physis growing-off the screw within two years. Linear and Cox regression analysis were conducted to identify factors related to HSA correction and risk of the physis growing-off the screw. RESULTS: A total of 37 hips in Group 1 and 24 hips in Group 2 were compared. Group 1 showed a more substantial decrease in the HSA (p = 0.003) and the MP (p = 0.032). Both groups had significant and similar improvements in the AI (p = 0.809) and the FAVA (p = 0.304). Group 1 presented a higher incidence of the physis growing-off the screw (p = 0.038). Results of the regression analysis indicated that the eccentricity of screw position correlated with HSA correction and increases the risk of the physis growing-off the screw. CONCLUSION: Guided growth is effective in improving coxa valga and excessive femoral anteversion in CP children. For younger children, despite compromised efficacy of varus correction, we recommend a more centered screw position, at least across the middle quarter of the medial physis, to avoid early revision. Cite this article: Bone Joint J 2020;102-B(9):1242-1247.

Can we predict failure of percutaneous fixation of femoral neck fractures?

PURPOSE: This study evaluated a series of geriatric femoral neck fracture treated with closed reduction percutaneous pinning (CRPP) at a single level-1 trauma center to determine if there are any simple, reliable, radiographic characteristics that can be used to predict increased risk of post-operative failure in nondisplaced and valgus impacted fracture patterns. METHODS: We conducted a retrospective cohort study of all patients with femoral neck fractures (AO/OTA 31B) who underwent CRPP over a 12-year period at a single Level 1 trauma center. Failure was defined as radiographic failure within the first year after the index operation requiring revision surgery. Common patterns identified on initial review were the presence of a visible medial transcervical line (MTL) felt to indicate a tension-sided failure, a straight inferior calcar (SIC) indicating severe valgus impaction, and quality of intra-operative screw positioning. X-rays of patients were then reviewed for these characteristics in a blinded manner by three different trauma-fellowship trained orthopedic surgeons. Inter-rater reliability was calculated using Fleiss' Kappa Coefficient. Comparisons of failure rates between groups were made using a Fisher's Exact test. RESULTS: 139 patients who underwent CRPP for a femoral neck fracture and follow-up for at least 90 days were identified and reviewed. There were a total of 19 failures (13.6%) within one year. The patients with a varus fracture had a failure rate of 9/24 (37.5%). Of the valgus/nondisplaced fractures, MTL was identified in 42/115 (36%) patients. Inter-rater agreement was high for the presence of an MTL (84%, Kappa 0.69). Patients with an MTL had a fourfold increase in risk of failure (7/42=17% with an MTL vs. 3/73=4% without, p  0.03). The presence of a SIC and quality of screw placement were not predictive of failure. CONCLUSION: Varus femoral neck fractures fixed with CRPP have a high rate of failure (37.5%). Nondisplaced or valgus impacted fractures with the presence of a visible medial transcervical line on pre-operative radiographic imaging resulted in a fourfold increase in the risk of failure after CRPP. Identification of the MTL will help treating surgeons better council patients when making pre-operative decisions between arthroplasty and CRPP.

Preoperative digital planning versus postoperative outcomes in total hip arthroplasty using a calcar-guided short stem: frequent valgization can be avoided.

INTRODUCTION: Modern total hip arthroplasty is largely dependent on the successful preservation of hip geometry. Thus, a successful implementation of the preoperative planning is of great importance. The present study evaluates the accuracy of anatomic hip reconstruction predicted by 2D digital planning using a calcar-guided short stem of the newest generation. METHODS: A calcar-guided short stem was implanted in 109 patients in combination with a cementless cup using the modified anterolateral approach. Preoperative digital planning was performed including implant size, caput-collum-diaphyseal angle, offset, and leg length using mediCAD II software. A coordinate system and individual scale factors were implemented. Postoperative outcome was evaluated accordingly and was compared to the planning. RESULTS: Intraoperatively used stem sizes were within one unit of the planned stem sizes. The postoperative stem alignment showed a minor and insignificant (p = 0.159) mean valgization of 0.5° (SD 3.79°) compared to the planned caput-collum-diaphyseal angles. Compared to the planning, mean femoral offset gained 2.18 (SD 4.24) mm, while acetabular offset was reduced by 0.78 (SD 4.36) mm during implantation resulting in an increased global offset of 1.40 (SD 5.51) mm (p = 0.0094). Postoperative femoroacetabular height increased by a mean of 5.00 (SD 5.98) mm (p < 0.0001) compared to preoperative measures. DISCUSSION: Two-dimensional digital preoperative planning in calcar-guided short-stem total hip arthroplasty assures a satisfying implementation of the intended anatomy. Valgization, which has been frequently observed in previous short-stem designs, negatively affecting offset, can be avoided. However, surgeons have to be aware of a possible leg lengthening.

Is there an Increase in Valgus Deviation in Tibial Distraction Using the Lengthening Over Nail Technique?

BACKGROUND: During tibial lengthening, the soft tissues of the posterolateral compartment produce distraction-resisting forces causing valgus angulation. Although this occurs with the classic Ilizarov method, whether a valgus deformity develops with the lengthening over nail (LON) technique is questioned, because the intramedullary nail is thought to resist deforming forces and adequately maintain alignment of the distracted bone. QUESTIONS/PURPOSES: The purposes of this study were to (1) determine the amount of valgus deviation during tibial lengthening with the LON technique; and (2) analyze the factors that may be associated with valgus deviation with the LON technique. METHODS: Between June 2009 and September 2013, we performed 346 tibial lengthenings using the LON technique, lengthening and then nail technique, or lengthening with an intramedullary lengthening device. Sixty patients (120 tibias) who underwent bilateral lower leg lengthening with the LON technique were enrolled in this retrospective study. To limit the number of variables, we analyzed only the right tibia in all patients (60 tibias). The mean followup was 42 months (range, 26-71 months). The mean age of the patients was 25 years (range, 18-40 years). There were 36 male and 24 female patients. The mean final length gain was 67 ± 9 mm. The mean time for distraction was 100 ± 25 days. The overall valgus deviation was assessed by measuring the change in the medial proximal tibial angle and mechanical femorotibial angle on radiographs obtained before and after surgery and after completion of lengthening. Several demographic, surgical, and distraction-related variables were considered possible factors to prevent valgus deviation: proximal fixation method; presence of a blocking screw; diameter and length of the intramedullary nail; degree of nail insertion; length of the nail in the distal segment after completion of distraction; final length gain; and patient's BMI. During the period studied, the blocking screw was to maintain the mechanical axis in patients who had neutral or valgus alignment preoperatively, or to prevent more valgus change in patients who underwent acute correction of varus deformity intraoperatively. Uni- and multivariate analyses were conducted. RESULTS: Valgus deviation occurred during the tibial LON. The medial proximal tibial angle increased from 86° (95% CI, 85°-86°) to 90° (95% CI, 89°-91°) (p < 0.001). The mechanical femorotibial angle changed from 2.2° varus (95% CI, 3°-1.4° varus) to 2.6° valgus (95% CI, 1.8°-3.4° valgus) (p < 0.001). Valgus deviation was evident in proximal and distal segments. In the multivariate regression model, use of a blocking screw was the only factor that was associated with decreased valgus deviation, and its effect size, although detectable, was small (-2.62; 95% CI, -4.65 to -0.59; p = 0.013). CONCLUSIONS: We found that valgus deviation does occur during tibial lengthening using the LON technique, but that blocking screw placement may help to minimize the likelihood that severe valgus deviation will occur. Future prospective studies should be conducted to confirm this preliminary finding. LEVEL OF EVIDENCE: Level III, therapeutic study.

Guided Growth of the Proximal Femur for Hip Displacement in Children With Cerebral Palsy.

BACKGROUND: Guided growth by 1 eccentric transphyseal screw has been used to correct lower limb deformities. Pilot animal studies showed encouraging results in producing varus deformity in the proximal femur. The purpose of this study was to report the preliminary results of guided growth surgery to treat spastic hip displacement. METHODS: This case series study included consecutive patients who received soft-tissue release and guided growth at the proximal femur from January 2004 to May 2012 with minimal 2-year follow-up. Surgical indications were children with spastic cerebral palsy aged 4 to 10 years, a gross motor function classification system level IV or V, and hip displacement on 1 or both sides. Study outcomes were Reimer's migration percentage (MP) and the head-shaft angle (HSA). RESULTS: Nine children with 13 spastic displaced hips received surgery at the age of 6.2 years and were followed up for a mean of 45.6 months. The mean MP improved significantly from 52.2% preoperatively to 45.8% at 3 months, 40.3% at 1 year, and 37.1% at 2 years after operation. HSA was unchanged in the first 3 months, and deceased from 173.3 to 166.4 degrees at 1 year (P<0.01) and to 162.7 degrees at 2 years postoperatively. The screw was usually backed out from the femoral epiphysis in the second postoperative year, and no radiologic bony bar or other surgical complications occurred. CONCLUSIONS: The immediate postoperative improvement of MP was the result of soft-tissue release. From postoperative 3 months to 2 years, the HSA was reduced by 10.6 degrees and the MP further improved by 8.7%. Less surgical dissection, faster recovery of motion, and less comorbidity than varus osteotomy make guided growth surgery a treatment option for coxa valga in spastic hip displacement in nonambulant cerebral palsy children. LEVEL OF EVIDENCE: Level IV-therapeutic, case series.

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.

Corrections of lower limb deformities in patients with diastrophic dysplasia.

OBJECTIVE: Accurate understanding of the cause of the underlying pathology in children with diastrophic dysplasia would help in designing targeted management of their locomotion. METHODS: Diastrophic dysplasia was diagnosed in twelve patients (nine girls and three boys; age range 1-14 years), all of whom presented with small stature and apparent short extremities. Club foot (mostly talipes equinovarus) was the most frequent and consistent abnormality. Concomitant abnormalities such as hip flexion contracture, flexion contractures of the knees with excessive valgus deformity and lateral patellar subluxation, were also encountered. Muscle ultrasound and muscle magnetic resonance imaging imaging showed no myopathic changes and muscle biopsies and the respiratory chain were normal. Serum choline kinase and plasma lactate concentrations were normal. RESULTS: Surgical correction of the foot and ankle in patients with diastrophic dysplasia is extremely difficult because of the markedly distorted anatomy. In all of these children, plantigrade foot was achieved along with the improved function of the locomotor system. Mutations of the diastrophic dysplasia sulfate transporter (also known as solute carrier family 26 member 2) were encountered. CONCLUSION: Arthrogryposis multiplex is the usual terminology used to describe the abnormality in infants with multiple contractures. Diligent orthopaedic care should be provided based on an accurate understanding of the associated syndromes in such children.

Kinematic gait analysis in children with valgus deformity of the hindfoot.

Deformities of the feet in children can influence not only optimal foot development but also the development of other body segments. The aim of the study was to compare the hip and pelvis kinematics in groups of children with and without valgus deformity of the hindfoot. Three groups of children participated in the study: bilateral hindfoot valgosity (11 children, age 5.4 ± 1.4 years), unilateral hindfoot valgosity (14 children, age 5.6 ± 1.6 years) and the control group (8 children, 4.8 ± 1.2). Hindfoot valgus angle was measured clinically during standing. Hindfoot valgosity was considered in the range of 6 to 20 degrees. Kinematic data from five trials for each child was obtained using the Vicon MX system (six infrared cameras, frequency 200 Hz, Vicon Motion Systems, Oxford, UK). The results of our study showed significantly higher pelvic anteversion during the whole gait cycle for both unilateral and bilateral hindfoot valgosity children and significantly higher hip external rotation during the first half of the stance phase in bilateral deformity. The differences in the hip and pelvis kinematics, when compared to the control group, are higher for the group with bilateral deformity than in the group with unilateral deformity.

Femoral bow predicts postoperative malalignment in revision total knee arthroplasty.

Diaphyseal bowing may compromise axial alignment in revision total knee arthroplasty (TKA). 277 patients undergoing revision TKA were evaluated for coronal bowing and hip-knee-ankle (HKA) axis. The mean femoral bow was 1.52° ± 0.18° varus (-10.1° to +8.4°). The mean tibial bow was 1.25° ± 0.13° valgus (-5.9° to +10°). HKA axis averaged 3.08° ± 0.35° varus preoperatively compared to 0.86° ± 0.25° varus postoperatively. Inter-rater and intra-rater reliability was high. Femoral bow greater than 4° significantly correlated with postoperative HKA axis malalignment (r = 0.402, P = 0.008). 39.7% of patients deviated 3° or greater from a neutral mechanical axis with a significant difference in femoral bow (0.94° ± 0.31°, P = 0.003). Diaphyseal bowing clearly has an important effect on postoperative limb alignment in revision TKA.

Hip dysplasia is more severe in Charcot-Marie-Tooth disease than in developmental dysplasia of the hip.

BACKGROUND: Patients with Charcot-Marie-Tooth disease may develop hip dysplasia. Hip geometry in these patients has not been well described in the literature. QUESTIONS/PURPOSES: We compared the hip morphometry in Charcot-Marie-Tooth hip dysplasia (CMTHD) and developmental dysplasia of the hip (DDH) in terms of extent of (1) acetabular dysplasia and subluxation, (2) acetabular anteversion and osseous support, (3) coxa valga and femoral version, and (4) osteoarthritis. METHODS: Fourteen patients with CMTHD (19 hips; mean age, 23 years) presenting for periacetabular osteotomy were matched to 45 patients with DDH (45 hips; mean age, 21 years) based on age, sex, and BMI. We assessed acetabular dysplasia and subluxation using lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), and acetabular roof angle of Tönnis (TA) on plain pelvic radiographs and acetabular volume, area of femoral head covered by acetabulum, and percentage of femoral head covered by acetabulum on three-dimensional CT reconstruction models. Acetabular version and bony support, femoral version, and neck-shaft angle were measured on two-dimensional axial CT scans. Hip osteoarthritis was graded radiographically according to Tönnis criteria. RESULTS: Acetabular dysplasia was more severe in CMTHD, as measured by smaller LCEA (p < 0.001), ACEA (p < 0.001), and acetabular volume (p = 0.0178) and larger TA (p = 0.025). Hip subluxation was more pronounced in CMTHD, as demonstrated by lower area of femoral head covered by acetabulum (p = 0.034) and percentage of femoral head covered by acetabulum (p = 0.007). CMTHD was associated with higher acetabular anteversion (p < 0.001), lower anterior (p < 0.001) and posterior (p = 0.072) osseous support, and more severe coxa valga (p < 0.001). More (p = 0.006) arthritic hips were found in CMTHD. CONCLUSIONS: The extent of acetabular dysplasia, hip subluxation, acetabular anteversion, coxa valga, and hip osteoarthritis was more severe in CMTHD. These findings are important in choosing the appropriate surgical strategy for patients affected by CMTHD.

Resemblance of valgus malalignment of the distal tibia in 15-degree craniocaudal radiographs.

PURPOSE: To describe and quantify a radiological phenomenon where the distal tibial plafond appears in valgus malalignment in intra-operative fluoroscopy owing to 15 degrees craniocaudal angulation of the X-ray beam. METHODS: The lateral distal tibial angle (LDTA) of 14 male and 9 female skeletally mature patients was measured by a single reviewer using 2 types of anteroposterior radiographs, in which the X-ray beam was projected at 0 (orthogonal to the ankle) and then at 15 (in a craniocaudal direction) degrees. The LDTA was the angle between the long axis of the tibia and a line drawn across the most radiodense part of the tibial plafond. The paired t-test was used to compare the LDTA of the 2 measurements. RESULTS: The mean LDTA on the 0-degree orthogonal radiographs was 89 (range, 87-92) degrees, whereas the mean LDTA on the 15-degree craniocaudal radiographs was 79 (range, 77-81) degrees. The mean difference was 10 degrees (range, 9-12; p<0.0001). In the 15-degree craniocaudal radiographs, the ankle joint appeared to have valgus malalignment. CONCLUSION: During intramedullary nailing of the tibia, the knee is usually flexed and the image intensifier may not swing over far enough. This can result in well-aligned reduction being incorrectly viewed as having valgus malalignment or a varus-malaligned fracture being incorrectly viewed as reduced.

[Crooked legs- just an aesthetic problem]. / Krumme Beine - mehr als ein ästhetisches Problem?

Because the lower extremities are weight bearing, malalignment plays a key role in the development of degenerative disease of the joints. This is particularly true as degenerative arthropathy is of mechanical and not inflammatory cause. Deviation of the axis has been shown to alter the load and force distribution in the joint and thereby causing excessive wear. Whether or not a deformity is clinically relevant or not depends on the symptoms, the amount of the deformity and the location of the deformity. Relevant deformities can be treated with orthotics or corrective osteotomies in early stages. In late stages fusions or joint replacement is the mainstay of treatment.

Parce que les extrémités inférieures portent un poids, un mauvais alignement de ces dernières joue un rôle clé dans le développement des atteintes dégénératives des articulations. Cela est particulièrement vrai puisque l'arthropathie dégénérative est d'origine mécanique et non pas inflammatoire. Une déviation axiale a été montrée modifier la répartition des charges et des forces dans l'articulation et provoquer ainsi un poids excessif. Qu'une déformation soit significative ou non sur le plan clinique dépend des symptômes, de l'importance et de la localisation de la déformation. Les déformations significatives peuvent être traitées dans des stades précoces par des ostéotomies orthotiques ou correctrices. Dans les stades tardifs des fusions ou des remplacements articulaires représentent les options thérapeutiques principales.

Conversion hemiarthroplasty and valgus osteotomy after failed ORIF of hip intertrochanteric fractures.

Hip arthroplasty after open reduction and internal fixation of the proximal femur presents a challenge to reconstructive surgeons. Bony defects, fracture malunion, and non-union increase the risk of complications, including intraoperative fracture, unrecognized perforation, and trochanteric non-union. The authors describe a novel surgical technique using conversion hemiarthroplasty and valgus osteotomy for failed open reduction and internal fixation of intertrochanteric hip fractures. The described surgical technique resulted in trochanteric advancement and preservation of the bone stock in the intertrochanteric region. This technique was successful in eliminating pain and restoring ambulation and abductor function and resulted in stable ingrowth and healing in these patients.

Adverse sequelae due to plate retention following submuscular plating for pediatric femur fractures.

OBJECTIVE: Submuscular plating has become a common operative treatment of length-unstable pediatric femur fractures. There has been no consensus regarding the need for plate removal after fracture union. The purpose of this report was to describe the potential constellation of findings that may occur with growth after plate retention. DESIGN: Retrospective case series. METHODS: A retrospective study was done on all patients who underwent a submuscular plate application for a pediatric femur fracture at our institution between 2003 and 2010 by the senior author. We reviewed the clinical and radiographic findings of patients who had returned for problems after being discharged from care after fracture union. RESULTS: We identified 3 patients who returned after having been discharged from care. All 3 patients had been treated with a distally contoured plate. All patients had findings of stress shielding, leg length discrepancy, valgus deformity of the femur, bony overgrowth of the plate, and screw tip prominence in the medial thigh. All these findings were related to plate migration secondary to the normal growth of the femur. One patient required a corrective osteotomy for significant limb malalignment, and 2 patients required removal of prominent distal screws. CONCLUSIONS: Submuscular plates that are distally contoured and applied in growing children for femoral fracture fixation should be removed after complete fracture healing to avoid the potential sequelae of plate retention seen with growth. LEVEL OF EVIDENCE: Therapeutic level IV.

Distal femoral valgus deformity following plate fixation of pediatric femoral shaft fractures.

BACKGROUND: This study investigated the frequency and potential risk factors associated with the development of distal femoral valgus deformity following plate fixation of diaphyseal femoral fractures in children. METHODS: Records of eighty-five skeletally immature patients who underwent plate fixation of a diaphyseal femoral fracture at a tertiary-care pediatric center from January 2003 to December 2010 were reviewed. Demographic data and clinical information were analyzed. Radiographic measurement of the distance from the distal plate edge to the distal femoral physis and of the anatomic lateral distal femoral angle was performed. Development of distal femoral valgus deformity was defined as a change in the anatomic lateral distal femoral angle of ≥5° in the valgus direction. Logistic regression analysis and contingency tables were used to relate the development of distal femoral valgus deformity with retention of hardware, patient age, fracture site, plate-to-physis distance, and the location of a bend in the plate at fixation. RESULTS: Midshaft fractures (45%) were more common than proximal or distal diaphyseal fractures. Intraoperatively, the plate was bent proximally or distally, or both, in 80% of the patients. Distal femoral valgus deformity of ≥5° was seen in ten patients, eight of whom had distal diaphyseal fractures. Three of the ten patients developed symptoms as a result of the distal femoral valgus deformity that required at least one unplanned additional surgical procedure. On the basis of the statistical analysis, patients with a plate-to-physis distance of ≤20 mm (relative risk= 12.77, p = 0.005) and a distal fracture (relative risk = 11.0, p < 0.001) were at a significantly higher risk of developing distal femoral valgus deformity. Although not clearly an independent factor, a distal bend was also found to be associated with distal femoral valgus deformity (p = 0.004) but was not predictive of the pathology. CONCLUSIONS: Distal femoral valgus deformity occurred in 30% of patients with distal diaphyseal fractures and in 12% overall. We advocate long-term monitoring of patients with femoral plate fixation, particularly those in whom the plate is placed ≤20 mm from the distal femoral physis.

Clinical implication of subgrouping in valgus femoral neck fractures: comparison of 31-B1.1 with 31-B1.2 fractures using the OTA/AO classification.

OBJECTIVES: This study aimed to identify the clinical implications of valgus-impacted femoral neck fractures and compare fractures with >15-degree angle of impaction (31-B1.1) against fractures with <15-degree angle of impaction (31-B1.2). DESIGN: Retrospective study. PATIENTS/PARTICIPANTS: We enrolled 78 patients with 31-B1 femoral neck fractures who were treated by screw osteosynthesis. MAIN OUTCOME MEASUREMENTS: We evaluated the clinical and radiographic outcomes. RESULTS: Thirty-six patients sustained 31-B1.1 fractures, and 42 patients sustained 31-B1.2 fractures. The average follow-up period was 15 months, and bony union occurred in all cases. The mean femur neck shortening was 8.88 mm for B1.1 and 3.70 mm for B1.2 fractures (P < 0.001). The mean sliding distance of the screw was 3.36 mm for B1.1 fractures and 1.38 mm for B1.2 fractures (P < 0.001). The mean Harris hip score was 82.0 for B1.1 and 88.8 for B1.2 fractures (P = 0.029). Avascular necrosis (AVN) of the femoral head occurred in 4 patients with B1.1 fractures, and none with B1.2 fractures (P = 0.041). Eighteen of the 78 patients required a second operation, and 15 of them were included in 31-B1.1 fracture (P = 0.003). Three patients underwent arthroplasty due to AVN, and 15 patients required hardware removal due to pain after bony union. CONCLUSIONS: More femoral neck shortening and less functional recovery should be expected in valgus-impacted femoral neck fracture patients based on the severity of the initial deformity. Even though we obtained bony union in all of the cases, the risk of AVN and second operation after bony union was higher with greater initial deformity. LEVEL OF EVIDENCE: Therapeutic level III.