Femoral Deformity Research Articles

NEUTRAL WEDGE DISTAL FEMORAL OSTEOTOMY (NWDFO) FOR CORRECTION OF LARGE VALGUS AND VARUS DEFORMITIES: TECHNIQUE AND RESULTS

IntroductionAngular deformities of the distal femur can be corrected by opening, closing and neutral wedge techniques. Opening wedge (OW) and closing wedge (CW) are popular and well described in the literature. CW and OW techniques lead to leg length difference whereas the advantage of neutral wedge (NW) technique has several unique advantages. NW technique maintains limb length, wedge taken from the closing side is utilised on the opening side and since the angular correction is only half of the measured wedge on either side, translation of distal fragment is minimum. Leg lengths are not altered with this technique hence a useful technique in large deformities. We found no reports of clinical outcomes using NW technique. We present a technique of performing external fixator assisted NW correction of large valgus and varus deformities of distal femur and dual plating and discuss the results.Materials & MethodsWe have treated 20 (22 limbs – 2 patients requiring staged bilateral corrections) patients for distal femoral varus and valgus deformities with CWDFO between 2019 and 2022. Out of these 4 patients (5 limbs) requiring large corrections of distal femoral angular deformities were treated with Neutral Wedge (NW) technique. 3 patients (four limbs) had distal femoral valgus deformity and one distal femoral varus deformity. Indication for NW technique is an angular deformity (varus or valgus of distal femur) requiring > 12 mm opening/closing wedge correction. We approached the closing side first and marked out the half of the calculated wedge with K – wires in a uniplanar fashion. Then an external fixator with two Schanz screws is applied on the opposite side, inserting the distal screw parallel to the articular surface and the proximal screw 6–7 cm proximal to the first pin and at right angles to the femoral shaft mechanical axis. Then the measured wedge is removed and carefully saved. External fixator is now used to close the wedge and over correct, creating an appropriate opening wedge on the opposite side. A Tomofix (Depuoy Synthes) plate is applied on the closing side with two screws proximal to osteotomy and two distally (to be completed later). Next the osteotomy on the opposite side is exposed, the graft is inserted. mLDFA is measured under image intensifier to confirm satisfactory correction. Closing wedge side fixation is then completed followed by fixation of opposite side with a Tomofix or a locking plate.Results3 patients (4 limbs) had genu valgum due to constitutional causes and one was a case of distal femoral varus from a fracture. Preoperative mLDFA ranged from 70–75° and in one case of varus deformity it was 103°. We achieved satisfactory correction of mLDFA in (85–90°) in 4 limbs and one measured 91°. Femoral length was not altered. JLCA was not affected post correction. Patients were allowed to weight bear for transfers for the first six weeks and full weight bearing was allowed at six weeks with crutches until healing of osteotomy. All osteotomies healed at 16–18 weeks (average 16.8 weeks). Patients regained full range of movement. We routinely recommend removal of metal work to facilitate future knee replacement if one is needed. Follow up ranged from 4 months to 2 yrs. Irritation from metal work was noted in 2 patients and resolved after removing the plates at 9 months post-surgery.ConclusionsNWDFO is a good option for large corrections. We describe a technique that facilitates accurate correction of deformity in these complex cases. Osteotomy heals predictably with uniplanar osteotomy and dual plate fixation. Metal work might cause irritation like other osteotomy and plating techniques in this location.

THE BELFAST TECHNIQUE FOR DEFORMITY CORRECTION OF FEMORAL COXA VARA IN OSTEOGENESIS IMPERFECTA: A NOVEL PLANNING AND SURGICAL TECHNIQUE

IntroductionOsteogenesis imperfect (OI) is a geno- and phenotypically heterogeneous group of congenital collagen disorders characterized by fragility and microfractures resulting in long bone deformities. OI can lead to progressive femoral coxa vara from bone and muscular imbalance and continuous microfracture about the proximal femur. If left untreated, patients develop Trendelenburg gait, leg length discrepancy, further stress fracture and acute fracture at the apex of the deformity, impingement and hip joint degeneration. In the OI patient, femoral coxa vara cannot be treated in isolation and consideration must be given to protecting the whole bone with the primary goal of verticalization and improved biomechanical stability to allow early loading, safe standing, re-orientation of the physis and avoidance of untreated sequelae. Implant constructs should therefore be designed to accommodate and protect the whole bone. The normal paediatric femoral neck shaft angle (FNSA) ranges from 135 to 145 degrees. In OI the progressive pathomechanical changes result in FNSA of significantly less than 120 degrees and decreased Hilgenreiner epiphyseal angles (HEA). Proximal femoral valgus osteotomy is considered the standard surgical treatment for coxa vara and multiple surgical techniques have been described, each with their associated complications. In this paper we present the novel technique of controlling femoral version and coronal alignment using a tubular plate and long bone protection with the use of teleoscoping rods.MethodologyAfter the decision to operate had been made, a CT scan of the femur was performed. A 1:1 scale 3D printed model (AXIAL3D, Belfast, UK) was made from the CT scan to allow for accurate implant templating and osteotomy planning. In all cases a subtrochanteric osteotomy was performed and fixed using a pre-bent 3.5 mm 1/3 tubular plate. The plate was bent to allow one end to be inserted into the proximal femur to act as a blade. A channel into the femoral neck was opened using a flat osteotome. The plate was then tapped into the femoral neck to the predetermined position. The final position needed to allow one of the plate holes to accommodate the growing rod. This had to be determined pre operatively using the 3D printed model and the implants. The femoral canal was reamed, and the growing rod was placed in the femur, passing through the hole in the plate to create a construct that could effectively protect both the femoral neck and the full length of the shaft. The distal part of the plate was then fixed to the shaft using eccentric screws around the nail to complete the construct.ResultsThree children ages 5,8 and 13 underwent the procedure. Five coxa vara femurs have undergone this technique with follow-up out to 62 months (41–85 months) from surgery. Improvements in the femoral neck shaft angle (FNSA) were av. 18o (10–38o) with pre-op coxa vara FNSA av. 99o(range 87–114o) and final FNSA 117o (105–125o). Hilgenreiner's epiphyseal angle was improved by av. 29o (2–58o). However only one hip was restored to <25o. In the initial technique employed for 3 hips, the plates were left short in the neck to avoid damaging the physis. This resulted in 2 of 3 hips fracturing through the femoral neck above the plate at approximately 1 year. There were revisions of the 3 hips to longer plates to prevent intra-capsular stress riser. All osteotomies united and both intracapsular fractures healed. No further fractures have occurred within the protected femurs and no other repeat operations have been required.ConclusionsSurgical correction of the OI coxa vara hip is complex. Bone mineral density, multiplanar deformity, a desire to maintain physeal growth and protection of the whole bone all play a role in the surgeon's decision making process. Following modifications, this technique demonstrates a novel method in planning and control of multiplanar proximal femoral deformity, resulting in restoration of the FNSA to a more appropriate anatomical alignment, preventing long bone fracture and improved femoral verticalization in the medium term follow-up.

Knee valgus and patellofemoral instability after pediatric anterior cruciate ligament reconstruction: a case report and review of the literature

BackgroundPediatric athletes who undergo anterior cruciate ligament reconstruction are at risk for a growth deformity if the surgery violates the physes.CaseA 12-year-old African American boy underwent anterior cruciate ligament reconstruction using a hamstring autograft. The procedure violated the distal femoral growth plate and the perichondrial ring of LaCroix, resulting in a distal femoral lateral physeal growth arrest. Three years later, he had developed a 15° valgus deformity, an increased quadriceps angle and patellofemoral instability. He was able to return to sports after undergoing a distal femoral osteotomy to correct the valgus and medial patellofemoral ligament reconstruction to stabilize the patella.ConclusionAnterior cruciate ligament reconstruction in athletes with open physes has the potential to cause distal femoral valgus deformity, an increased quadriceps angle, and subsequent patellofemoral instability.

Minimally Invasive Correction of Proximal Femoral Valgus Deformity in Cerebral palsy

Minimally Invasive Correction of Proximal Femoral Valgus Deformity in Cerebral palsy

Reliability of the Modified Method for Sphericity Deviation Score Using Only the Involved Hip Radiographs in the Patients With Legg-Calve-Perthes Disease.

The sphericity deviation score (SDS) is a validated radiographic outcome measure that quantifies the severity of the femoral head deformity in the healed stage of Legg-Calve-Perthes disease (LCPD). The current method requires radiographs of both hips regardless of unilateral involvement to standardize radiographic magnification. As LCPD affects the unilateral hip in 85% to 90% of cases, the current method imposes unnecessary radiation exposure to most of the patients and having to exclude patients from research studies who only had unilateral hip radiographs. We thus modified the SDS method to use unilateral hip radiographs. The purpose of this study was to investigate the reliability of the modified SDS method using the radiographs containing only one hip. This retrospective study involved 40 patients with LCPD with unilateral involvement in the healed stage of LCPD. We modified the SDS measurement method by using the distance between the teardrop and the lateral acetabulum for magnification correction and providing a clear anatomic description of reference points on the femoral head. Three independent observers performed measurements using radiographs containing the affected hip only (modified method) and both hips (conventional method). The intraclass correlation (ICC) estimates were calculated. To verify clinical relevance, the correlation of the SDS with the Stulberg classification and hip range of motion (ROM) were also investigated. Measurements using the modified SDS showed excellent inter-/intra-observer ICCs (0.903 to 0.978). The ICCs between the modified and conventional methods were also excellent: 0.940 to 0.966 within the same observer and 0.897 to 0.919 between different observers. The modified SDS showed moderate-to-strong correlations with the Stulberg classification (Spearman ρ=0.650) and hip ROM (Pearson r =-0.661). The modified SDS measurement method showed excellent inter-/intra-observer reliability and moderate-to-strong correlations with the Stulberg classification and hip ROM. This method will help reduce unnecessary radiation exposure in patients with unilateral LCPD and prevent the exclusion of patients with unilateral radiographs from future research studies. Level III-diagnostic study.

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

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

In closed wedge distal femur osteotomies for correction of valgus malalignment overcorrection of mLDFA should be avoided.

The purpose of the study was to investigate the influence of the mLDFA (mechanical lateral distal femur angle) as a parameter in varus realignment osteotomies for valgus deformities of the knee. We hypothesized that joint line obliquity with mLDFA > 90° after distal femur osteotomy (DFO) is associated with inferior clinical outcome. In a retrospective study, a total of 52 patients with isolated femoral valgus deformities were included in the study. The mean postoperative follow-up was 70.5 (SD 33.3) months (standard deviation SD±33.3). In all patients, a distal femur osteotomy was performed. A clinical examination and survey of questionnaires was conducted with the HSS (Hospital for Special Surgery), LG (Lysholm-Gilquist), and KOOS (Knee Injury and Osteoarthritis Outcome Score) scores. Several radiological parameters were assessed on long-standing x-rays: mechanical tibio-femoral angle (mTFA), mLDFA, mechanical medial proximal tibia angle (mMPTA), joint-line convergence angle (JLCA). The ttest was used for normally distributed data. The Mann-Whitney U test was performed in non-normally distributed data. The mLDFA was 84.9° (SD±2.3) preop and changed to 91.9° (SD±3, 22.9) postop. The mTFA (mechanical tibio-femoral angle) was 5.2° (SD±2.9°) preop and -1.8° (SD±2.9) postop demonstrating a difference of 6.7°. For analysis, the data was divided into two groups based on postop mLDFA. Group 1: mLDFA ≤ 90°; Group 2: > 90°. Postoperatively, a mean mLDFA of 88.6° (SD±1.4°) was measured in group 1 and 93.9° (SD±2.1) in group 2. The change in mLDFA was 4.7° (SD±1.6) in group 1 and 8.4° (SD±2.8) in group 2. Preoperatively, the mTFA was 4.8° (SD±1.9) in group 1 and 5.5° (SD±3.3) in group 2. Postoperatively, the mTFA decreased in group 1 by 4.8° (SD±2.3) to -0.1° (SD±2.1). In group 2, the mTFA decreased by 8.2° (SD±3.8) to -2.8° (SD±2.9). Regarding the HSS, group 1 showed a 10.4 points better score than group 2 (p<0.01). Also, regarding the Lysholm, a significant difference of 16.9 points was found (p<0.01). Correction of valgus knees using closed wedge DFO leads to good clinical results. A postoperative mLDFA of 85-90° results in superior clinical outcome compared to mLDFA > 90°. Joint-line obliquity should be avoided using double level osteotomy, if needed. III.

Superior Hip Dislocation in a Child

Superior hip dislocation is a rare entity reported in the medical literature. Superior hip dislocation in the pediatric age is even rarer. Careful clinical and radiological assessment helps to diagnose these injuries early for their appropriate management. We, hereby, describe a case of superior hip dislocation in a 10-year-old child following fall from a tree. The characteristic attitude of limb and radiological correlation helped in prompt diagnosis which was then followed by an emergent closed and successful reduction. The stable and concentric reduction was achieved and no re-dislocation was noted in the follow-up of 8 months. The child shall be under periodic review for future complications such as avascular necrosis, arthritis, or femoral head deformity among other potential complications.

Application of 3D-printed osteotomy guide plates in proximal femoral osteotomy for DDH in children: a retrospective study

BackgroundPatients with developmental dysplasia of the hip (DDH) have complex proximal femoral deformities, and orthopedic surgery lacks objectivity. Expectations for surgical outcomes are often not achieved, and postoperative problems are common. Using 3D-printed technology in orthopedics offers a novel approach to precise and individualized treatment in modern orthopedics. The aim of this study was to investigate the value of the application of 3D-printed osteotomy guide plates in femoral osteotomy. The clinical indices of femoral osteotomy in children with DDH using 3D-printed osteotomy guide plates were compared with those of traditional osteotomy.MethodsThe clinical data of children with DDH who underwent open reduction and Salter pelvic osteotomy combined with femoral osteotomy from September 2010 to September 2020 were retrospectively collected and analyzed. Based on the inclusion and exclusion criteria, a total of 36 patients were included in the study: 16 in the guide plate group and 20 in the conventional group. Operation time (total), operation time (femoral side), X-ray fluoroscopy times (total), X-ray fluoroscopy times (femoral side) and intraoperative blood loss were analyzed and compared between the two groups. Comparison of treatment-related indicators such as postoperative neck-shaft angle, postoperative anteversion angle, hospitalization time, and hospitalization expenses is made between the two groups. The two groups of patients were evaluated at the last follow-up using the McKay clinical evaluation criteria.ResultsBetween the two groups, there were significant differences in operation time (total), operation time (femoral side), X-ray fluoroscopy times (total), X-ray fluoroscopy times (femoral side) and intraoperative blood loss (P < 0.05). The postoperative neck-shaft angle, postoperative anteversion angle, hospitalization time and hospitalization expenses did not differ significantly (P > 0.05). The MacKay clinical evaluation did not significantly differ at the most recent follow-up (P > 0.05).ConclusionsChildren with DDH undergoing proximal femoral osteotomy using 3D-printed osteotomy guide plates benefit from a simpler surgical procedure, shorter operative time, less bleeding and less radiation exposure during surgery. This technique is of great clinical value.

Computed tomographic angular measurements using a bone-centered three-dimensional coordinate system are accurate in a femoral torsional deformity model and precise in clinical canine patients.

In small animal orthopedics, angular measurements in the canine femur are often applied in clinical patients with bone deformities and especially in complex and severe cases. Computed tomography (CT) has been shown to be more precise and accurate than two-dimensional radiography, and several methods are described. Measurement techniques evaluated in normal bones must prove accuracy in deformed bones in clinical settings. The goals of our study were to evaluate the accuracy of canine femoral torsion angle measurements in a femoral torsional deformity model and to test repeatability and reproducibility of canine femoral neck inclination, torsion, and varus angle measurements in CT datasets of dogs applying a CT-based technique using a three-dimensional (3D) bone-centered coordinate system. For precision testing, femoral torsion, femoral neck inclination, and femoral varus angles were measured in CT data of 68 canine hind limbs by two operators, and their results were compared. For accuracy testing, a femoral torsional deformity model was preset from 0° to +/-90° with a goniometer and scanned. Torsion angles were measured in the CT data and compared to the preset value. In the femoral torsion model, the Bland-Altman plots demonstrated a mean difference of 2.11°, and the Passing-Bablok analysis demonstrated a correlation between goniometer and CT-based measurements. In the clinical CT scans, intra- and interobserver agreement resulted in coefficients of variation for repeated measurements (%) between 1.99 and 8.26 for the femoral torsion, between 0.59 and 4.47 for the femoral neck inclination, and between 1.06 and 5.15 for the femoral varus angles. Evaluation of femoral malformations with torsional deformities is the target area of this technique. Further studies are required to assess its value in different types, degrees, and combinations of osseous deformities and to establish normal reference values and guidelines for corrective osteotomies. Based on the results of this study, the accuracy of the torsion angle measurements and the precision of inclination, torsion, and the varus angle measurements were considered acceptable for clinical application.

Hip Pain after Distal Femoral Derotational Osteotomy for a Patient with Patellar Instability: A Case Report

Increased torsional deformity of femur is one of the most important factors in recurrent patellofemoral instability. And distal femoral derotational osteotomy is an effective treatment option in patients with increased femoral torsional deformity. However, groin pain is a rare complication after femoral derotational osteotomy. The patient was a 23-year-old female suffering from anterior knee pain and patellar instability in her left leg. Continuous CT scans of the hip, knee, and ankle were performed and the femoral anteversion was 44.99°. Considering the significant enlargement of the femoral internal torsion which may contribute most for dislocation of patella, we did a derotational osteotomy of distal femur. The anterior knee pain and patellar instability were resolved after surgery. The femoral internal torsion angle was corrected to 21.47°. But she developed left hip pain in the groin area which she had never encountered before 1 year after the surgery. We believed that the hip pain was closely related to the surgery. And the imaging and follow-up partly confirmed this. The situation of the hip joint should be carefully evaluated before doing derotational osteotomy in recurrent patellofemoral instability and patient should be informed that derotational osteotomy may cause hip pain. Clinical studies are needed to further clarify the impact of derotational osteotomy on the hip.

FINITE ELEMENT ANALYSIS OF THE IMPINGING HIP: SUBJECT-SPECIFIC MODELS TO ASSESS THE RISK OF OSTEOARTHRITIC DEGENERATION

Femoro-acetabular impingement involves a deformity of the hip joint and is associated with hip osteoarthritis. Although 15% of the asymptomatic population exhibits a deformity, it is not clear who will develop symptoms. Current diagnostic imaging measures have either low specificity or low sensitivity and do not consider the dynamic nature of impingement during daily activities. The goal of this study is to determine stresses in the cartilage, subchondral bone and labrum of normal and impinging hips during activities such as walking and sitting down.Quantitative CT scans were obtained of a healthy Control and a participant with a symptomatic femoral cam deformity (‘Bump’). 3D models of the hip were created from automatic segmentation of CT scans. Cartilage layers were added so the articular surface was the mid-line of the joint. Finite element meshes were generated in each region. Bone elastic modulus was assigned element-by-element, calculated from CT intensity converted to bone mineral density using a calibration phantom. Cartilage was modelled as poroelastic, E=0.467 MPa, v=0.167, and permeability 3×10-16 m4/N s. The pelvis was fixed while rotations and contact forces from Bergmann et al. (2001) were applied to the femur over one load cycle for walking and sitting in a chair. All analyses were performed in FEBio.High shear stresses were seen near the acetabular cartilage-labrum junction in the Bump model, up to 0.12 MPa for walking and were much higher than in the Control.Patient-specific modelling can be used to assess contact and tissue stresses during different activities to better understand the risk of degeneration in individuals, especially for activities that involve high hip flexion. The high stresses at the cartilage labrum interface could explain so-called bucket-handle tears of the labrum.

Impact of the diaphyseal femoral deformity on the lower limb alignment in osteoarthritic varus knees

The impact of a diaphyseal femoral deformity on knee alignment varies according to its severity and localization. The aims of this study were to determine a method of assessing the impact of diaphyseal femoral deformities on knee alignment for the varus knee, and to evaluate the reliability and the reproducibility of this method in a large cohort of osteoarthritic patients. All patients who underwent a knee arthroplasty from 2019 to 2021 were included. Exclusion criteria were genu valgus, flexion contracture (> 5°), previous femoral osteotomy or fracture, total hip arthroplasty, and femoral rotational disorder. A total of 205 patients met the inclusion criteria. The mean age was 62.2 years (SD 8.4). The mean BMI was 33.1 kg/m2 (SD 5.5). The radiological measurements were performed twice by two independent reviewers, and included hip knee ankle (HKA) angle, mechanical medial distal femoral angle (mMDFA), anatomical medial distal femoral angle (aMDFA), femoral neck shaft angle (NSA), femoral bowing angle (FBow), the distance between the knee centre and the top of the FBow (DK), and the angle representing the FBow impact on the knee (C'KS angle). The FBow impact on the mMDFA can be measured by the C'KS angle. The C'KS angle took the localization (length DK) and the importance (FBow angle) of the FBow into consideration. The mean FBow angle was 4.4° (SD 2.4; 0 to 12.5). The mean C'KS angle was 1.8° (SD 1.1; 0 to 5.8). Overall, 84 knees (41%) had a severe FBow (> 5°). The radiological measurements showed very good to excellent intraobserver and interobserver agreements. The C'KS increased significantly when the length DK decreased and the FBow angle increased (p < 0.001). The impact of the diaphyseal femoral deformity on the mechanical femoral axis is measured by the C'KS angle, a reliable and reproducible measurement.

Intraosseous injection of mesenchymal stem cells for the treatment of osteonecrosis of the immature femoral head and prevention of head deformity: A study in a pig model.

Cell therapy has been proposed as part of the therapeutic arsenal to assist bone formation and remodeling in the early stages of osteonecrosis of the femoral head. The purpose of this study is to determine the effects of intraosseous inoculation of mesenchymal stem cells on bone formation and remodeling in an established experimental model of osteonecrosis of the femoral head in immature pigs. Thirty-one 4-week-old immature Yorkshire pigs were used. Experimental osteonecrosis of the femoral head was created in the right hip of all included animals (n = 31). The month after surgery, hip and pelvis radiographs were taken to confirm osteonecrosis of the femoral head. Four animals were excluded following surgery. Two groups were established: (A) mesenchymal stem cell-treated group (n = 13) and (B) saline-treated group (n = 14). One month after surgery the mesenchymal stem cell-group received an intraosseous injection of 10 × 106 mesenchymal stem cell (5 cc) and the saline-treated group of 5 cc of physiological saline solution. Osteonecrosis of the femoral head progression was assessed by monthly X-rays (1-, 2-, 3- and 4-months post-surgery). The animals were sacrificed 1 or 3 months following the intraosseous injection. Repair tissue and osteonecrosis of the femoral head were histologically evaluated immediately after sacrifice. At time of sacrifice, radiographic images showed evident osteonecrosis of the femoral head with associated severe femoral head deformity in 11 of the 14 animals (78%) in the saline group and in only 2 of the 13 animals (15%) in the mesenchymal stem cell group. Histologically, the mesenchymal stem cell group showed less osteonecrosis of the femoral head and less flattening. In the saline group, there was pronounced femoral head flattening and the damaged epiphyseal trabecular bone was largely replaced with fibrovascular tissue. Intraosseous mesenchymal stem cells inoculation improved bone healing and remodeling in our immature pig osteonecrosis of the femoral head model. This work supports further investigation to determine whether mesenchymal stem cells enhance the healing process in immature osteonecrosis of the femoral head.

Posterior Pubic Incidence: A Novel Morphologic Spinopelvic Parameter Nearly Equal to Pelvic Incidence.

Pelvic incidence (PI) and Jackson's angle are 2 major spinopelvic parameters that define the position of the sacrum within the pelvis. These parameters are measured on standing lateral radiography, and the identification of the hip axis is essential for measurements. Moreover, identifying the hip axis in patients with hip diseases or femoral head deformity is challenging. In this study, we described a novel parameter named posterior pubic incidence (PPI) that could be measured using the posterior pubic edge instead of the hip axis. Group A comprised 50 volunteers who underwent standing lateral lumbosacral radiography. Group B comprised 54 patients with abdominal or urologic problems who underwent supine computed tomography. The PI, pelvic tilt (PT), sacral slope, PPI, and posterior pubic tilt were measured. The differences between PI and PPI were evaluated. Linear regression analysis was used to predict the PI value from PPI. The mean PI and PPI values were 47.41°±12.32° and 49.32°±11.94° in group A and 49.19°±9.99° and 49.99°±9.25° in group B, respectively. The mean absolute differences in groups A and B were 2.41°±1.63° and 1.9°±1.62°, respectively. High correlations were obtained between PI/PPI and pelvic tilt/posterior pubic tilt. PI could be calculated as PI°=PPI°- 2° on plain radiography and as PI°=PPI°- 1° on computed tomography. PPI was strongly correlated with PI, which was nearly equal to PI, and may replace PI in formulas containing PI.

Preoperative MR imaging for hip dysplasia : Assessment of associated deformities and intraarticular pathologies

Developmental dysplasia of the hip (DDH) is aknown reason for hip pain for adolescents and young adults. Preoperative imaging is increasingly recognized as an important factor due to the recent advances in MR imaging. The aim of this article is to give an overview of preoperative imaging for DDH. The acetabular version and morphology, associated femoral deformities (cam deformity, valgus and femoral antetorsion) and intraarticular pathologies (labrum and cartilage damage) and cartilage mapping are described. After an initial evaluation with AP radiographs, CT or MRI represent the methods of choice for the preoperative evaluation of the acetabular morphology and cam deformity, and for the measurement of femoral torsion. Different measurement techniques and normal values should be considered, especially for patients with increased femoral antetorsion because this could lead to misinterpretation and misdiagnosis. MRI allows analysis of labrum hypertrophy and subtle signs for hip instability. 3DMRI for cartilage mapping allows quantification of biochemical cartilage degeneration and yields great potential for surgical decision-making. 3D-CT and, increasingly, 3DMRI of the hip to generate 3Dpelvic bone models and subsequent 3Dimpingement simulation can help to detect posterior extraarticular ischiofemoral impingement. Acetabular morphology can be divided in anterior, lateral and posterior hip dysplasia. Combined osseous deformities are common, such as hip dysplasia combined with cam deformity (86%). Valgus deformities were reported in 44%. Combined hip dysplasia and increased femoral antetorsion can occur in 52%. Posterior extraarticular ischiofemoral impingement between the lesser trochanter and the ischial tuberosity can occur in patients with increased femoral antetorsion. Typically, labrum damage and hypertrophy, cartilage damage, subchondral cysts can occur in hip dysplasia. Hypertrophy of the muscle iliocapsularis is a sign for hip instability. Acetabular morphology and femoral deformities (cam deformity and femoral anteversion) should be evaluated before surgical therapy for patients with hip dysplasia, considering the different measurement techniques and normal values of femoral antetorsion.

Surgical treatment for ipsilateral femoral neck and shaft fracture

To retrospectively analyze efficacy of single structure internal fixation and double structure internal fixation in the treatment of ipsilateral femoral shaft and neck fracture, and analyze their indications. From June 2015 to December 2020, 21 patients with ipsilateral femoral shaft and femoral neck fracture were treated, including 14 males and 7 females, aged 23 to 69 years old with an average of(38.1±12.9) years old. According to different femoral shaft fracture sites, some patients were fixed with cephalomedullary implant for both femoral neck and the femoral shaft(single structure, InterTan or PFNA Ⅱ), some patients were fixed with cannulated screws for the femoral neck and a retrograde locking nail for the femoral shaft (dual structure), and postoperative function and complications were recorded during follow-up. In 10 cases of single-structure fixation, the femoral necks were all basicervical fractures, and the femoral shaft fractures were located in the proximal isthmus;11 cases were double-structure fixation, 9 cases in 11 were basal type of femoral neck, 2 cases in 11 were neck type, and the femoral shaft fractures were located in the isthmus and the distal isthmus. All patients were followed up for 12 to 27 months. No femoral head necrosis, deformity, delay or nonunion occurred in the patients with single-structure fixation, and no delayed union or nonunion occurred in femoral shaft fractures;At the final follow-up, Harris score of patients with single-structure fixation was 91.8±4.1, with 8 cases were excellent and 2 cases were good. The fractures of patients with dual-structure fixation achieved good union without femoral head necrosis, except 1 case of femoral shaft fracture had delayed union;At the final follow-up, Harris score of patients with dual-structure fixation was 92.4±5.9, 7 cases were excellent, 3 cases were good, and 1 case was fair. Good reduction and fixation is the key to the treatment of such fractures. Both the single-structure fixation and the dual-structure fixation are good methods, and it should be selected according to the locations of femoral shaft and femoral neck fractures. Single-structure fixation is a good choice for femoral shaft fractures located at the proximal isthmus and basal femoral neck fractures. For isthmus and distal femoral shaft fractures combined with ipsilateral femoral neck fractures, dual-structure fixation is recommended.

Predicting Rates of Angular Correction After Hemiepiphysiodesis in Patients With X-Linked Hypophosphatemic Rickets.

Patients with X-linked hypophosphatemic rickets (XLH) often develop coronal plane knee deformities despite medical treatment. Hemiepiphysiodesis is an effective way to correct coronal plane knee deformities in skeletally immature patients, but a full understanding of the rate of angular correction after hemiepiphysiodesis in XLH patients, compared with idiopathic cases is lacking. We retrospectively reviewed charts of 24 XLH patients and 37 control patients without metabolic bone disease who underwent hemiepiphysiodesis. All patients were treated with standard-of-care medical therapy (SOC=active vitamin D and phosphate salt supplementation) in our clinical research center and had a minimum of 2-year follow-up after hemiepiphysiodesis. Demographic data as well as complications, repeat procedures, or recurrence/overcorrection were recorded. Standing lower extremity radiographs were evaluated before the surgical intervention and at subsequent hardware removal or skeletal maturity, whichever came first. Mean axis deviation, knee zone, mechanical lateral distal femoral angle (mLDFA), and medial proximal tibial angle were measured on each radiograph. The rate of angular correction was calculated as the change in mLDFA and medial proximal tibial angle over the duration of treatment. The magnitude of the initial deformity of the distal femur was greater in XLH patients as compared with control for varus (XLH mLDFA 97.7 +/- 4.9 vs. Control mLDFA 92.0 +/- 2.0 degrees) and valgus (XLH mLDFA 78.7 +/- 6.2 vs. Controls mLDFA 83.6 +/- 3.2 degrees). The rate of correction was dependent on age. When correcting for age, XLH patients corrected femoral deformity at a 15% to 36% slower rate than control patients for the mLDFA (>3y growth remaining XLH 0.71 +/- 0.46 vs. control 0.84 +/- 0.27 degrees/month, <3y growth remaining XLH 0.37 +/- 0.33 vs. control 0.58 +/- 0.41 degrees/month). No significant differences were seen in the rate of proximal tibia correction. XLH patients were less likely to end treatment in zone 1 (55.0% XLH vs. 77.8% control). XLH patients had longer treatment times than controls (19.5 +/- 10.7 vs. 12.6 +/- 7.0mu, P value <0.001), a higher average number of secondary procedures than controls (1.33 +/- 1.44 vs. 0.62 +/- 0.92 number of procedures), a higher rate of overcorrection than controls (29.2% vs. 5.4%), and a higher rate of subsequent corrective osteotomy than controls (37.5% vs. 8.1%). There was no significant difference in the rate of complications between groups (8.3% vs. 5.4%). Patients with XLH undergoing hemiepiphysiodesis have a 15% to 36% slower rate of femoral deformity correction that results in longer treatment times, a higher likelihood to undergo more secondary procedures, and a lower likelihood to reach neutral mechanical alignment. This study provides important information to guide the timing and treatment of patients with XLH and coronal plane knee deformities. In addition, results from this study can be educational for families and patients with respect to anticipated treatment times, success rates of the procedure, complication rate, and likelihood of needing repeat procedures.

Intussusception Allograft Prosthetic Composites in Total Hip Arthroplasty: A Salvage Operation for Extensive Femoral Bone Loss

BackgroundAllograft prosthetic composites (APCs) have been used to perform revision total hip arthroplasty (THA) for massive femoral bone loss or deformity. Intussusception, or “telescoping”, APC techniques have been proposed to enhance the contact area of this interface and provide superior mechanical fixation over conventional methods. The purpose of this study is to present to our knowledge, the largest series of telescoping APC THAs, along with surgical technique details and midterm (average 5-10 years) clinical results. MethodsBetween 1994 and 2015, 46 revision THAs performed with proximal femoral telescoping APCs were retrospectively reviewed at a single institution. Overall survival, reoperation-free survival, and construct survival rates were calculated via Kaplan-Meier methods. In addition, radiographic analyses were performed to evaluate for component loosening, union at the APC-host interface, and resorption of the allograft. ResultsAt 10 years, the overall patient survival was 58%, reoperation-free survival was 76%, and construct survival was 95%. Reoperation was performed in 20% (n = 9) and only 2 constructs required resection. Radiographic analyses performed at latest follow-up revealed no instances of radiographic femoral stem loosening, an 86% union rate at the APC-host site, 23% with signs of some allograft resorption, and a 54% trochanteric union. The mean postoperative Harris hip score was 71 points (range, 46-100). ConclusionTelescoping APCs are technically demanding, but provide reliable mechanical fixation for the reconstructing of large proximal femoral bone deficits in revision THA with excellent construct survivorship, acceptable reoperation rates, and good clinical outcomes. Level of EvidenceIV.

The treatment of a femoral shaft fracture in patients with a previous post-traumatic femoral deformity using a Clamshell osteotomy.

The aim of this study was to assess the safety and clinical outcome of patients with a femoral shaft fracture and a previous complex post-traumatic femoral malunion who were treated with a clamshell osteotomy and fixation with an intramedullary nail (IMN). The study involved a retrospective analysis of 23 patients. All had a previous, operatively managed, femoral shaft fracture with malunion due to hardware failure. They were treated with a clamshell osteotomy between May 2015 and March 2020. The mean age was 42.6 years (26 to 62) and 15 (65.2%) were male. The mean follow-up was 2.3 years (1 to 5). Details from their medical records were analyzed. Clinical outcomes were assessed using the quality of correction of the deformity, functional recovery, the healing time of the fracture, and complications. The mean length of time between the initial injury and surgery was 4.5 years (3 to 10). The mean operating time was 2.8 hours (2.05 to 4.4)), and the mean blood loss was 850 ml (650 to 1,020). Complications occurred in five patients (21.7%): two with wound necrosis, and three with deep vein thrombosis. The mean coronal deformity was significantly corrected from 17.78° (SD 4.62°) preoperatively to 1.35° (SD 1.72°) postoperatively (p < 0.001), and the mean sagittal deformity was significantly corrected from 20.65° (SD 5.88°) preoperatively to 1.61° (SD 1.95°; p < 0.001) postoperatively. The mean leg length discrepancy was significantly corrected from 3.57 cm (SD 1.27) preoperatively to 1.13 cm (SD 0.76) postoperatively (p < 0.001). All fractures healed at a mean of seven months (4 to 12) postoperatively. The mean Lower Extremity Functional Scale score improved significantly from 45.4 (SD 9.1) preoperatively to 66.2 (SD 5.5) postoperatively (p < 0.001). Partial cortical nonunion in the deformed segment occurred in eight patients (34.8%) and healed at a mean of 2.4 years (2 to 3) postoperatively. A clamshell osteotomy combined with IMN fixation in the treatment of patients with a femoral shaft fracture and a previous post-traumatic femoral malunion achieved excellent outcomes. Partial cortical nonunions in the deformed segment also healed satisfactorily.