Evaluation of the functional outcome of a percutaneous technique in correction of excessive anteversion in cerebral palsy.

In cerebral palsy, patients' excessive femoral anteversion is one of the most common skeletal abnormalities. The general agreement is concurrent correction of both soft tissue and bony deformities during the same operative setting by combining open femoral derotation osteotomy (FDO) with soft tissue releases. Fifty-one children (75 lower limbs) with cerebral palsy with a mean age of 10.7 years (range 6-16 years) fulfilling the inclusion criteria who underwent percutaneous FDO and when needed customized soft tissue releases. Derotation was maintained by a pin-in-cast technique. The mean follow-up was 24 m (range 14-36 m) and gross motor function classification system, functional mobility scale (FMS) and anteversion angle using the Staheli rotational profile were evaluated. Femoral anteversion was accurately measured by hip ultrasonography followed by a preoperative three-dimensional gait analysis. Preoperative and postoperative data were statistically analyzed to reveal the validity of this method. Internal and external hip rotation improved significantly (P < 0.001, respectively). Mean cast and Schanz screw application time was 49 days and all patients achieved independent walking for at least 5 m within 7 weeks. FMS, ultrasonography measured hip anteversion and gait kinematics also improved significantly (P < 0.01, respectively). Two patients (3.92%) developed a mild knee flexion contracture which resolved completely with physiotherapy at 12 m. The pins-in-fiberglass cast provides sufficient rigid fixation to constitute a reliable and reproducible method permitting early weight bearing. It is versatile enough to allow concomitant soft tissue procedures and correction of other accompanying bony deformities.

Optimal Level of Femoral Neck for Predicting Postoperative Stem Anteversion in Total Hip Arthroplasty for Crowe Type I Dysplastic Hip.

OBJECTIVE: This study aimed to investigate the optimal level of femoral neck for measuring femoral anteversion to predict postoperative stem anteversion in Crowe type I developmental dysplasia of the hip. METHODS: This retrospective study analyzed 108 Crowe type I hips that underwent THA between January 2016 and December 2017, including 70 women and 19 men with a mean age of 63.08 ± 9.13 (range, 41-83) years. The single-wedge stem was used in 37 hips, the double-wedge stem was used in 71 hips. Computed tomography scans were performed pre- and post-operation. Femoral anteversion at six levels of the proximal femur were measured via preoperative two-dimensional computed tomography. Femoral anteversion at the level of the femoral neck osteotomy plane and postoperative stem anteversion were measured via three-dimensional reconstructed models. RESULTS: The mean follow-up period was 18.5 months (range, 12-27). The mean preoperative Harris Hip Score was 51.5 ± 8.7 and improved to 90.4 ± 7.8 (P < 0.001) by the last follow-up. There were no intraoperative fractures, and no infections occurred during the follow-up period. Two patients developed deep venous thrombosis. There was no sign of prosthetic loosening in all hips. No significant correlations were found between the height of the femoral neck osteotomy plane and postoperative stem anteversion (r = -0.119, P = 0.220). Femoral anteversion decreased gradually from 64.00° ± 10.51° at the center of lesser trochanter to 15.21° ± 13.31° at the head-neck junction, which was changed from more to less than stem anteversion (24.37° ± 13.86°). The femoral anteversion at femoral head-neck junction (15.21° ± 13.31°) was significantly less than postoperative stem anteversion (P = 0.000), with a difference of -9.16° ± 9.27°. The femoral anteversion at the level of the osteotomy plane (28.48° ± 15.34°) was significantly more than the postoperative stem anteversion (P = 0.000), with a difference of 4.11° ± 9.56°. Among all six levels and the level of osteotomy, femoral anteversion at the 10-mm level above the proximal base of lesser trochanter (22.65 ± 12.92) displayed the smallest difference (-1.72° ± 8.90°) and a good correlation (r = 0.764) with postoperative stem anteversion for all 108 hips, with a moderate correlation of 0.465 for single-wedge stem hips and an excellent correlation of 0.821 for double-wedge stem hips. CONCLUSION: For Crowe type I hips, femoral anteversion would be different if it was measured via different levels of the femoral neck. The 10-mm level above the proximal base of the lesser trochanter could be an optimum choice for measuring femoral anteversion to predict postoperative stem anteversion.

Effect of a modular neck hip prosthesis on anteversion and hip rotation in total hip arthroplasty for developmental dysplasia of the hip.

Total hip arthroplasty (THA) is often required to decrease the excessive anatomical femoral anteversion (AA) in developmental dysplasia of the hip. Studies have recommended decreasing the AA via the use of a retroverted modular neck. However, hip rotation after THA may strengthen or weaken the effect of changing the AA. Thus, the present study analyzed the effect of a retroverted neck on AA and hip rotation. Patients who underwent THA using a straight neck (ST group) or a 15° retroverted neck (RV group) in a version changeable dual modular system (Mainstay stem, Kyocera, Kyoto, Japan) were retrospectively reviewed. After matching for age, body mass index, and surgical approach, 44 patients were included in each group. The AA and hip rotation (femoral rotational angle: FRA) were measured on CT images acquired preoperatively and 1 month after THA, and were compared between the groups. The mean ± standard deviation preoperative AA of the ST group (26.1 ± 10.7°) was significantly smaller than that of the RV group (44.2 ± 7.8°) (p < 0.001). In contrast, the postoperative AA did not significantly differ between the groups (ST group 27.5 ± 9.8°, RV group 25.1 ± 8.3°, p = 0.406). The change in FRA after THA did not significantly differ between the groups (ST group - 3.8 ± 9.9°, RV group - 3.5 ± 9.1°, p = 0.841). In conclusion, a 15° retroverted neck was useful in controlling AA in hips with excessive AA, and the change in FRA after THA did not differ between the ST group and the RV group.

Medial unicompartmental knee arthroplasty to patients with a ligamentous deficiency can cause biomechanically poor outcomes.

PURPOSE: The aims of this study were to investigate the biomechanical effects of the deficiency of the collateral ligament and cruciate ligament in medial unicompartmental knee arthroplasty in normal and varus knee patients using computational simulation. METHODS: Validated finite-element (FE) models for conditions of various cruciate and collateral ligament deficiencies were developed to evaluate the biomechanical effects of ligamentous deficiency in UKA for normal and varus knee patients. Contact stresses on the polyethylene (PE) insert, contact stresses on the lateral articular cartilage, and quadriceps force were analyzed under gait-loading conditions. RESULTS: Contact stresses on the PE insert and lateral articular cartilage as well as quadriceps force in a normal knee UKA FE model were increased in the order of anterior cruciate ligament (ACL) deficiency, medial collateral ligament (MCL) deficiency, lateral collateral ligament (LCL) deficiency, and posterior cruciate ligament (PCL) deficiency in the stance phase of gait cycle, as compared with those in the model without ligamentous deficiency. In two or more multiple ligamentous deficiencies, contact stresses on the PE insert and articular lateral cartilage and quadriceps force were significantly increased versus in the case of single-ligament deficiency. CONCLUSION: Poor outcomes of medial UKA in patients with ACL or MCL deficiency can be predicted. Care should be taken to extend the indications when performing medial UKA in patients with ligamentous deficiency, especially when varus knee with ACL or MCL deficiency is present.

Anatomic stem inserted according to native anteversion could reproduce the native anterior distance of the femoral head and decrease bony impingement in total hip arthroplasty.

PURPOSE: To investigate whether anatomic and straight stems could reproduce the anteroposterior distance (AD) of the native femoral head and evaluate the effect of AD of the femoral head on range of motion (ROM) and bony impingement. METHODS: This retrospective simulation study included 64 patients who had undergone primary total hip arthroplasty between 2012 and 2014. Using computed tomography (CT)-based templating software, anatomic and straight stems were inserted with same alignment. AD of the head centre was compared between the two stems and native anatomy. Furthermore, post-operative ROM was calculated, and correlation between AD and ROM was assessed. RESULTS: There was a strong positive correlation between native anteversion (mean 21.9°) and anatomic stem anteversion (mean 22.5°) (R = 0.975, P < 0.001). There was no significant difference in AD between the native and anatomic stems (mean 37.7 and 38.8 mm, respectively), but AD of the straight stem was significantly lower than that of the native and anatomic stems. The straight stem showed a significantly lower ROM in flexion and internal rotation angles with 90° flexion (IR) than the anatomic stem (P < 0.05 and P < 0.001, respectively). AD showed a stronger correlation with ROM of IR than with stem anteversion. CONCLUSIONS: The anatomic stem could reproduce AD of the native femoral head centre, but the head centre of the straight stem in the same anteversion with anatomic stem translated significantly posterior, significantly decreasing the ROM of flexion and IR and increasing bony impingement of IR. To avoid bony impingement and acquire sufficient ROM, reproducing AD was important.

Good Outcomes of Combined Femoral Derotation Osteotomy and Medial Retinaculum Plasty in Patients with Recurrent Patellar Dislocation.

OBJECTIVES: To report the clinical outcomes of combined femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation in patients with excessive femoral anteversion. METHODS: From January 2015 to March 2018, 20 knees in 20 patients (18 female, 2 male) with a mean age of 21 ± 4.2 years (range, 16 to 28 years) were retrospectively reviewed. All patients had undergone femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation and excessive femoral anteversion angle (FAA > 25°). CT and X-rays were used to assess the correction of the femoral anteversion angle, the tibia tuberosity-trochlear groove (TT-TG) distance, patellar tilt, and the congruence angle following the combinatory operations. Subjective scores, such as Kujala, International Knee Documentation Committee (IKDC), Tegner, and visual analogue scale (VAS) scores, were used to evaluate knee function preoperatively and postoperatively. RESULTS: No recurrence of patellar dislocation occurred in these patients during an average of 18 months (range, 12 to 23 months) of follow-up. The mean of the FAA was corrected to 15.80° ± 3.58° postoperatively compared with 31.42° ± 4.95° preoperatively (P < 0.001). The TT-TG distance was decreased from 22.17 ± 5.28 mm before surgery to 19.42 ± 4.57 mm after surgery (P = 0.03). The patellar tilt and congruence angle were improved from 30.43° ± 5.30°, 43.30° ± 11.04° to 15.80° ± 3.94°, 16.64° ± 9.98°, respectively (P < 0.001). The Kujala score was improved from 72.4 ± 19.90 before the surgery to 88.2 ± 12.25 after the surgery (P < 0.001). The IKDC score was improved from 70.56 ± 21.44 to 90.78 ± 14.32, and the VAS score was decreased from 4.23 ± 2.11 preoperatively to 1.27 ± 1.08 postoperatively (P < 0.001). No significant difference in Tegner score (5.46 ± 2.49 vs 5.79 ± 1.44) was found before and after the surgery (P = 0.2). Patients younger than 20 years old had lower Kujala (83.46 ± 14.56 vs. 90.84 ± 7.74, P = 0.02) and IKDC (83.49 ± 17.35 vs 92.46 ± 9.28, P = 0.04) scores than those older than 20 years. CONCLUSION: Good knee function, pain relief, and improved patellofemoral congruence were achieved with the combined femoral derotation osteotomy and medial retinaculum plasty. The combined operations serve as an ideal treatment for recurrent patellar dislocation and address the primary risk factors.

Non-equivalent Results from Different Anteversion Measurements Methods for the Evaluation of the Acetabular Cup Orientation in Total Hip Arthroplasty.

OBJECTIVE: To determine the comparability among 10 radiographic anteversion methods for acetabular cup orientation in total hip arthroplasty (THA) found in the literature and the "gold" standard of assessing the anteversion with CT. METHODS: This is a retrospective study that blindly compares 10 different conventional radiographic anteversion measurements with the "gold" standard, the measurement of anteversion on the transverse plane of the 3-D images made with CT. The patient archiving and communications system (PACS) was systematically searched for subjects that had undergone a CT angiogram of the abdomen and lower extremities, including the pelvis, had at least one THA in situ and had undergone anterior-posterior (AP) and cross-lateral pelvic radiography between January 2013 and August 2016 in the Diakonessenhuis Hospital Utrecht/Zeist, a non-academic institution. CT scans of patients (n = 16) were systematically collected. Three observers independently measured cup anteversion from radiographs, using a total of 10 different methods, and measured the "gold" standard on CT images. The outcomes of the 10 radiographic anteversion were compared in terms of linear correlation with the "gold" standard on CT images. RESULTS: The correlations of the radiographic measured anteversions with the "gold" standard measured on CT images were 0.528 for the method of Liaw, 0.556 for Wan, 0.562 for the cross-lateral method, 0.586 for Hassan, 0.594 for Dorr, 0.602 for Lewinnek, 0.624 for Widmer, 0.671 for the lateral CT, 0.747 for Ackland, and 0.771 for the method of Riten Pradham. CONCLUSION: Anteversion measurement methods represent different projectional angles of the acetabular cup in different planes around different axes. Therefore, they differ from the "gold" standard and are not interchangeable, as is shown by this study. We consider the anatomical anteversion in the transverse plane rotating around the longitudinal axis as the "gold" standard and recommend avoiding using the term anteversion for other projectional angles in different planes.

Midterm follow-up of closing wedge high tibial osteotomy with upper tibiofibular joint capsulotomy.

Closing wedge high tibial osteotomy is a popular surgery for correcting varus knee in symptomatic patients. One of the major drawbacks of this method is complications related to fibular osteotomy. This study describes pearl and pitfalls of closing wedge high tibial osteotomy with upper tibiofibular joint capsulotomy, avoiding fibular osteotomy and proposes that it has less complications and better results. Closing wedge high tibial osteotomy with upper tibiofibular joint capsulotomy was carried on 34 knees (19 patients) between September 2011 and June 2015 (thirteen males and six females). Operated men were between 19 and 38 years with mean 21 years. Operated women were between 23 years and 51 years. Considering that only one woman was 23 years old and the other four were between 45 and 51, better results and fewer complications were obtained in younger individuals with less body mass index and milder deformities. As a conclusion, when selecting patients, it is vital to stick to inclusion criteria. When in two or more factors, the patient is close to upper limits of inclusion criteria, unsatisfactory outcomes might be expected.

Sagittal Imbalance Does Not Influence Cup Anteversion in Total Hip Arthroplasty Dislocations.

STUDY DESIGN: Retrospective Cohort. SUMMARY OF BACKGROUND DATA: Studies have shown that lumbar fusion procedures are associated with an increased risk of total hip arthroplasty (THA) dislocation. Some have speculated that the increased risk of dislocation is caused by mispositioning of the acetabular component because of spinal sagittal imbalance. Unfortunately, the exact relationship between spinal sagittal balance and cup orientation is unknown. OBJECTIVE: The objective of this study was to investigate the effect of spinal sagittal alignment on cup anteversion in THA dislocation. METHODS: Patients that suffered a THA dislocation were retrospectively identified. Cross-table lateral hip radiographs were used to measure cup anteversion with normal acetabular anteversion defined as 15±10 degrees. Lateral lumbar spine radiographs were used to measure lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt, and sacral slope. Normal sagittal balance was defined as a PI-LL difference of <10 degrees. The association between sagittal balance and THA characteristics was assessed using Pearson correlation coefficient, χ analysis, and independent t tests. RESULTS: A total of 29 patients had full radiographic imaging. Among these patients, 62.1% dislocated following a primary THA and 37.9% following a revision THA. Abnormal spinal sagittal balance was identified in 20 patients (69.0%). Eight (27.6%) patients had undergone spinal fusion prior to THA. Abnormal cup anteversion was demonstrated in 51.7% of all patients. Presence of a spinal fusion was not associated with cup anteversion, sagittal balance, or time to dislocation. Sagittal balance was not associated with direction of dislocation, time to dislocation, or cup anteversion. CONCLUSIONS: A majority of patients with a THA dislocation demonstrated abnormal sagittal balance. However, sagittal balance was not associated with acetabular cup anteversion. As such, the relationship between spinal deformity and dislocation rates after THA may not be because of inaccurate cup orientation.

Comparison of the outcome between unilateral and bilateral open wedge high tibial osteotomy in the bilateral varus knees.

INTRODUCTION: Bilateral open wedge high tibial osteotomy (OWHTO) can be performed in a staged manner to enable the healing and rehabilitation of each limb separately after surgery. However, the effects of staged bilateral OWHTO on the pattern of recovery and changes over time for each limb have not been established. Additionally, there is a lack of information regarding the optimal timing for staged surgery. METHODS: Twenty-two patients (44 knees) in the bilateral OWHTO group and 42 patients (42 knees) in the unilateral OWHTO group were analyzed. Clinical and radiological results were evaluated and compared between the two groups. For the alignment change assessment, the hip-knee-ankle (HKA) angle and weight-bearing line (WBL) ratio were measured preoperatively and at postoperative 6 weeks, 3 months, 6 months, and 1 year. RESULTS: The correction loss of HKA angle in the bilateral OWHTO group was significantly larger than that in the unilateral OWHTO group (0.5° ± 1.4° vs 1.3° ± 2.0°, p = 0.049). The correction loss of WBL ratio was significantly greater in the patients with staged bilateral OWHTO within a 3-month interval compared to those with staged bilateral OWHTO in an interval longer than 3 months (WBL ratio; 7.5% vs 2.1%, p = 0.01). There was no significant difference in the clinical scores and range of motion at the last follow-up. CONCLUSION: The smaller loss of correction in the unilateral OWHTO group occurred compared to the bilateral OWHTO group. Additionally, surgeons should keep in mind that the amount of correction loss may be greater if staged bilateral OWHTO is performed at intervals of 3 months or less.

Knee Pain and Activity Outcomes After Femoral Derotation Osteotomy for Excessive Femoral Anteversion.

BACKGROUND: Excessive femoral anteversion is a developmental condition that can become symptomatic into adolescence and manifest as anterior knee pain, tripping, and or problems with sports. Femoral derotational osteotomy about an antegrade intramedullary nail (IMN) is an accepted option to treat this condition. This is the first report of the clinical and functional outcomes of treatment of excessive anteversion with femoral derotational osteotomy stabilized with an IMN. METHODS: We prospectively enrolled 28 consecutive patients between 2013 and 2014 who underwent derotational osteotomy. Physical examination measures were used to calculate the amount of angular correction with focus on internal and external rotation of the hip, as well as the trochanteric prominence angle test of femoral anteversion. The International Knee Documentation Committee-9, Marx, and Tegner activity scales were 3 patient-reported outcomes recorded. RESULTS: After femoral derotation osteotomy over an IMN, femoral anteversion, as measured by the trochanteric prominence angle, improved an average of 29 degrees (P<0.0001). At 1-year minimum follow-up, 22 of 28 subjects (78.5%) demonstrated a mean significant improvement of 13 points for International Knee Documentation Committee-9 (SD=15.4, P=0.0007), which surpassed the level of minimal clinically important change. Furthermore, the Tegner inventory scores for the cohort improved by an average of 1.9 activity levels (SD=2.4, P=0.0012). CONCLUSIONS: For adolescents with symptomatic excessive femoral anteversion, derotational osteotomy over an IMN offers a reliable surgical option that provides predictable deformity correction and significant improvements in both function and pain scales. LEVELS OF EVIDENCE: Level II-prospective, consecutive, nonrandomized, internally controlled cohort study.

Spinopelvic parameter changes and low back pain improvement due to femoral neck anteversion in patients with severe unilateral primary hip osteoarthritis undergoing total hip replacement.

PURPOSE: The study of the interrelation between hip and spine disorders is gaining increasing importance in the last years, but the link between Hip Osteoarthritis (HOA) and Low Back Pain (LBP) remains still unclear. Aim of the study is to assess the relationship between Femoral Neck Anteversion (FNA), LBP, and spinopelvic parameters in patients undergoing Total Hip Replacement (THR) for unilateral severe primary HOA. MATERIALS AND METHODS: 91 patients were recruited. Inclusion criteria were: grade 5 or 6 unilateral HOA, according to Turmezei, and Harris Hip score (HHS) <60. Exclusion criteria were: secondary hip osteoarthritis (dysplasia of the hip, rheumatoid arthritis, and ankylosing spondylitis); previous surgery of the spine, hip or knee; scoliosis with a Cobb angle greater than 10°; spondylolisthesis; history of spine fractures; previous bone tuberculosis or any spine infections; any contraindications to CT; BMI >30. Patients were divided into two homogeneous Groups according to the presence (Group-A) or not of concomitant LBP (Group-B). All patients underwent preoperatively a hip CT scan to evaluate FNA, Acetabular Anteversion (AA), and Combined Anteversion (CA = FNA + AA). ΔFNA, ΔAA and ΔCA were calculated as the differences between the arthritic hip and the normal hip angles in each Group. Full spinal X-rays in upstanding position were performed before (baseline) and 6 months after THR (follow-up) to calculate spinopelvic parameters. The health-related quality of life (HRQoL) was evaluated at baseline and at follow-up using Visual Analogue Scale (VAS), HHS, Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RM), and Short-Form Health Survey (SF-36). The intra-group and inter-group variability were assessed using, respectively, paired and unpaired t tests. At baseline, the association between HRQoL scores and ΔFNA, ΔAA, and ΔCA was analysed by the Pearson correlation test. RESULTS: At baseline, in Group-A, there was a significant difference between arthritic FNA and normal hip FNA, while no differences were found in AA between the two hips. A close correlation was observed between ΔFNA and Spine-VAS (r = 0.788), ODI (r = 0.824), and RM (r = 0.775). In Group-B, there was not a significant difference in FNA and AA between the two hips. At recruitment, in Group-A patients, we recorded a higher LL, SS, PI, SVA(C7), and a lower PT and T1-SPI compared with Group-B subjects. Six months after THR, in Group-A, an improvement of all clinical scores was recorded, as well as, a significant reduction of SS, LL, T1PA, and SVA(C7) and an increment of PT. In Group-B, at follow-up, an improvement of HHS, Hip-VAS, and SF-36 was recorded, while the changes in spinopelvic parameters were not significant. CONCLUSIONS: Patients with concomitant unilateral HOA and LBP showed a marked anteverted FNA in the arthritic hip and a spinopelvic misalignment. After THR, a relief of both hip and low back pain and a change in spinopelvic parameters is observed.

Transverse Acetabular Ligament as an Anatomical Landmark for Intraoperative Cup Anteversion in Primary Total Hip Replacement.

OBJECTIVE: To assess the results of the use of transverse acetabular ligament (TAL) as an intraoperative indicator for acetabular cup anteversion alignment during total hip replacement. STUDY DESIGN: Case series. PLACE AND DURATION OF STUDY: The Nursing Home Hospital in Baghdad Medical City Complex, Baghdad, Iraq, from October 2014 to June 2015. METHODOLOGY: Patients were operated through a posterolateral approach for primary total hip arthroplasty (THA) in which transverse acetabular ligament (TAL) was identified and used as indicator for cup anteversion. Those with previous surgery and secondary osteoarthritis due to dysplasia or tumor were excluded. Postoperative anteversion angles were measured by using anteroposterior pelvic radiographs using Pardhan method by two different observers and the perceived quality of operative outcome was directly asked to the patient. RESULTS: There were a total of 31 patients. The anteversion angle ranged between 5.7 - 24.40°. In addition, the calculated mean angle of 14.7 degrees for the current study sample did not obviously or significantly depart from the required optimum angle of 15 degrees defined by Lewinnek (15 ±10°, p=0.82). For the perceived quality of operative outcome, good outcome (satisfied) was expressed by two-thirds (67.7%) of study subjects after four weeks of surgery. CONCLUSION: Using transverse acetabular ligament as an intraoperative landmark is a simple, effective, and patientspecific method for proper cup anteversion placement in primary THA.

Comparison of Intraoperative Fluoroscopic Dunn View With Magnetic Resonance Imaging to Determine Femoral Version.

PURPOSE: To compare femoral version measured with a fluoroscopic Dunn view taken at the time of hip arthroscopy with values derived from axial magnetic resonance imaging (MRI) scans. METHODS: Of 159 hip arthroscopies performed from January 2014 through March 2015, 50 patients had magnetic resonance imaging (MRI) scans with a protocol that incorporates femoral version analysis. Dunn views are performed as a routine part of the preoperative fluoroscopic examination at the time of arthroscopy. Femoral version was measured from the fluoroscopic views and compared with values calculated from axial MRI images. The measurements were compared with a paired t test for difference in means, the intraclass correlation coefficient (ICC) for reliability, and the limits of agreement method of Bland and Altman. RESULTS: There was a very small but statistically significant difference between the measurement on fluoroscopic Dunn view and the value on axial MRI (mean difference, 1.4°, P = .03). The ICC was 0.809 (P < .0001), indicating substantial agreement. By the Bland and Altman method, the 95% limits of agreement for fluoroscopic versus MRI measurement were -7.6 to 10.4, with no significant difference in variance by Pitman test (P = .526). CONCLUSIONS: With careful attention to technique, the fluoroscopically simulated Dunn view can be used to measure femoral version with acceptable accuracy and obviates the need for repeat 3-dimensional imaging for patients who already have an MRI scan without version analysis. LEVEL OF EVIDENCE: Level II, testing of previously developed diagnostic criteria with a gold standard.

The effect of valgus and varus femoral osteotomies on measures of anteversion in the dog.

OBJECTIVE: To determine whether femoral osteotomies that change frontal plane alignment without affecting torsion influence anteversion and inclination. METHODS: Femurs without deformity were scanned to create three-dimensional reconstructions. The femoral head-neck axis was identified by placement of a virtual intramedullary pin. A proximal osteotomy was simulated to create three conditions while keeping torsion constant: Normal, Coxa Valga (neck-shaft angle increased by 12°), and Coxa Vara (neck-shaft angle decreased by 12°). Femoral anteversion was measured from an axial image in all three conditions. Femoral inclination was calculated for all conditions using the neck-shaft and anteversion angles. Changes in anteversion and inclination were calculated and compared using a one-way repeated measures analysis of variance. Distal femoral osteotomies were then simulated with the native femurs, inducing 18° of distal varus with no change to torsion. Changes in anteversion and inclination for the Normal and Distal Varus conditions were calculated and compared by a paired t-test. RESULTS: Version changed by a mean of 13.9° (± 1.5; p <0.0001) from the Coxa Valga to Coxa Vara conditions while inclination changed by a mean of 1.3° (± 0.39; p <0.01). Version changed by a mean of 6.6° (± 0.7; p <0.0001) between the Distal Varus and Normal conditions while inclination changed by a mean of -3.8° (± 0.75; p <0.001). CLINICAL SIGNIFICANCE: Femoral version changes with changing frontal plane alignment even when torsion is constant. This should be considered when correcting femoral deformities.

Contribution of clinical gait analysis to single-event multi-level surgery in children with cerebral palsy.

Clinical gait analysis (CGA) has been proven useful in understanding the gait disturbances seen in children and adolescents with cerebral palsy. Another major benefit provided by CGA is a clinical and scientific evaluation of how orthopaedic surgical procedures modify gait. The information provided by instrumented CGA complements the clinical data, and the two must be interpreted jointly. Although there is some variability in the surgical details of therapeutic strategies, CGA undoubtedly influences the planning of surgery. Although CGA improves surgical outcomes, these remain challenging to predict. CGA seems cost-effective. Internal hip rotation gait is used as an example to illustrate those benefits.

Biomechanical changes associated with femoral derotational osteotomy.

Torsional deformities of the femur in children may occur as a result of either idiopathic or neuromuscular disorders and may be corrected with derotational osteotomies. Regardless of the underlying etiology, neither the effects of the torsional pathologies nor the alterations resulting from corrective osteotomies are well understood. A study of children with isolated femoral anteversion undergoing a single corrective procedure may assist in understanding the biomechanics of the pathology and the efficacy of surgical correction. A multicenter retrospective study included 25 subjects with idiopathic femoral anteversion who underwent femoral derotational osteotomy and had completed pre and postoperative gait analyses. Both changes with surgery and comparisons to typically developing controls were analyzed. Reduced gait pathology and expected improvements in hip rotation and foot progression were found with derotational osteotomy. Overall gait pathology and pathological differences in pelvic tilt, hip flexion moment and knee adduction moment were found comparing anteversion subjects with typically developing subjects. Following surgery, only hip rotation was significantly and clinically different from typically developing subjects, changing from relatively inward to outward. Idiopathic femoral anteversion creates multifaceted and significant alterations to normal gait and should not be considered solely a cosmetic issue. Additionally, the efficacy of derotational osteotomy is illustrated and may be more broadly applied to other conditions where pathologic femoral anteversion is present.

Accuracy of combined anteversion in image-free navigated total hip arthroplasty: stem-first or cup-first technique?

PURPOSE: In total hip arthroplasty (THA), combined anteversion (CA) is used as a parameter for assessment of overall prosthetic alignment. The purpose of this study was to comparatively examine the CA value in patients who underwent primary THA using the image-free navigation system either with a cup-first or stem-first technique. METHODS: Eighty-three hips undergoing primary THA using the OrthoPilot® image-free navigation system (B. Braun-Aesculap, Tuttlingen, Germany) were included in this study. The patient population was divided into two groups depending on the procedure used: cup-first technique and stem-first technique. In the cup-first group, inclination and anteversion (AV) angles were targeted at 35-45° and 15-25°, respectively, while stem antetorsion (AT) was determined for each patient based on the amount of individual native femoral AT angle. In the stem-first group, the femur was prepared first with the target angle corresponding to the native femoral AT and the cup AV was decided considering the CA calculated with Widmer's formula (aiming at the optimal Widmer's CA of 37.3°). RESULTS: Better consistency in Widmer's CA values was attained in the stem-first group as indicated by the smaller SD values. In the assessment of overall alignment, Widmer's CA values were within the satisfactory range (37 ± 5°) in 41.9 and 92.3 % of the subjects in the cup-first group and the stem-first group, respectively. CONCLUSIONS: The stem-first technique with image-free navigated THA could effectively achieve accurate and consistent control of the CA value and thus is expected to improve the surgical outcome.

Factors associated with recurrence after femoral derotation osteotomy in cerebral palsy.

Femoral derotation osteotomy (FDO) as gold standard treatment for internal rotation gait in cerebral palsy (CP) leads to satisfying short-term results, whereas rates of recurrence up to 33% are reported in long-term outcome studies. The purpose of this study was therefore to identify factors contributing to recurrence of internal rotation gait in patients with CP who were treated with FDO in childhood. 70 patients (age: 10 (± 3.3) years at surgery) with bilateral CP and internal rotation gait were examined pre-, one year and at least five years (mean 8 ± 2 years) postoperatively after distal or proximal FDO, using standardized clinical examination and 3D gait-analysis. 27 patients had a good hip rotation one year postoperatively (between 5° external and 15° internal for both limbs) and were considered for the analysis of factors contributing to recurrence of internal rotation gait. Regarding all included patients both mean hip rotation and foot progression angle improved significantly (p < 0.001) from pre- to postoperative. A significant deterioration in hip rotation (more involved side) (p < 0.001) from one year postoperatively to the long-term follow-up can be observed. Younger age, reduced hip joint impulse, increased plantar flexion and internal foot progression angle postoperatively could be identified as factors for recurrence. FDO on average leads to a satisfactory correction of internal rotation gait. In order to improve the long-term outcome after FDO the time of multilevel surgery should be indicated as late as possible and the different factors leading to potential recurrence should be considered.