Weight-bearing Portion Research Articles

MEDIAL PLANTAR ARTERY FLAP FOR RECONSTRUCTION OF HEEL PAD DEFECTS

Introduction: Soft-tissue injury of heel pad is challenging to deal with due to limited reconstructive options. Masquelet and Romana described medial plantar artery flap to reconstruct heel pad with like with like tissue and with lesser donor-site morbidity. Materials and Methods: The study includes 10 patients with soft tissue defects of the heel pad who presented between 2022- 2024. The patients were followed up for a maximum period of 2 years. Results: Ten patients with soft tissue defects of the heel underwent medial plantar artery flap were included in the study. Conclusion: The medial plantar artery flap is a suitable option for the reconstruction of soft tissue defects in the weight-bearing portion of the heel, resulting in excellent functional outcomes. Source of support: Nil Conflict of interest: None.

Tissue-Engineered Bone Regeneration for Medium-to-Large Osteonecrosis of the Femoral Head in the Weight-Bearing Portion: An Observational Study.

Stem cell therapy for the treatment of osteonecrosis of the femoral head (ONFH) showed promising outcomes. However, ONFH with a large lesion in the weight-bearing portion is a poor prognostic factor and still challenging issue to be solved. We aimed to evaluate the effect of tissue-engineered bone regeneration for this challenging condition to preserve the femoral head. A total of 7 patients (9 hips) with ONFH who received osteoblasts expanded ex vivo from bone marrow-derived mesenchymal stem cells (BMdMSCs) and calcium metaphosphate (CMP) as scaffolds from March 2002 to March 2004 were retrospectively reviewed. The median age was 27.0 years (interquartile range [IQR], 23.0-34.0 years), and the median follow-up period was 20.0 years (IQR, 11.0-20.0 years). After culture and expansion of stem cells, we performed core decompression with BMdMSC implantation at a median number of 10.1 ×107 (IQR, 9.9-10.9 ×107). To evaluate radiographic outcomes, the Association Research Circulation Osseous (ARCO) classifications, the Japanese Investigation Committee (JIC) classification, and modified Kerboul combined necrotic angle (mKCNA) were evaluated preoperatively and during follow-up. Clinical outcomes were evaluated by a visual analog scale (VAS) and Harris Hip Score (HHS). The preoperative stage of ONFH was ARCO 2 in 5 hips and ARCO 3a in 4 hips. The ARCO staging was maintained in 3 hips of ARCO 2 and 4 hips of ARCO 3a. Two hips of ARCO 2 with radiographic progression underwent total hip arthroplasty. According to mKCNA, 2 hips showed medium lesions, and 7 hips showed large lesions. The size of necrotic lesion was decreased in 4 hips (2 were ARCO 2 and 2 were ARCO 3a). There were no significant changes in JIC classification in all hips (type C1: 3 hips and type C2: 6 hips) (p = 0.655). Clinically, there were no significant changes in the VAS and HHS between preoperative and last follow-up (p = 0.072 and p = 0.635, respectively). Tissue engineering technique using osteoblasts expanded ex vivo from BMdMSC and CMP showed promising outcomes for the treatment of pre-collapsed and early-collapsed stage ONFH with medium-to-large size, mainly located in weight-bearing areas.

Comparison of instep and non-instep flap in the reconstruction of the weight-bearing portion of the forefoot and heel.

Instep flaps are commonly used for the reconstruction of weight-bearing areas of the foot. However, in cases of large defects or damage to the instep area, non-instep flaps such as reverse sural flaps (RSF) or free anterolateral thigh flaps (ALTF) can be employed. Previous studies have primarily focused on heel reconstruction when comparing different flaps, without considering the forefoot. This study aims to verify the clinical outcomes of these flaps and determine the appropriate donor site for weight-bearing areas of the foot including forefoot reconstruction. In a retrospective study, 39 patients who had undergone flap reconstruction of weight-bearing area defects in the foot with a follow-up period of ≥1 year were included. The patients were categorized into two groups: Group A (n = 19) using instep flaps, and Group B (n = 20) using non-instep flap including RSFs and ALTFs. Surgical outcomes were assessed based on the success of the flap, the presence of partial necrosis, the number of additional surgeries, and complications related to the donor site. Clinical evaluation included visual analogue scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS) score, and the occurrence of ulcers. All flaps were successful, while partial necrosis occurred in one case in Group B. There were three reclosures after flap border debridement in both groups and one donor site debridement in Group A. The VAS scores during weight-bearing were 2.0 ± 1.1 and 2.2 ± 1.5 for Groups A and B, respectively (p = .716). The AOFAS scores were 52.8 ± 6.8 and 50.2 ± 12.7 for Groups A and B, respectively (p = .435). The occurrence of ulcers was 0.4 ± 0.9 times for Group A and 0.3 ± 0.7 times for Group B, with no significant difference between the two groups (p = .453). There was no difference in clinical outcomes between the types of flaps after reconstruction of the forefoot and hindfoot. Therefore, it is recommended to choose the appropriate flap based on factors such as the size of the defect, its location, and vascular status rather than the type of flap.

Evaluation of articular cartilage degeneration in patients with osteonecrosis of the femoral head using T2 mapping magnetic resonance imaging.

To evaluate and characterise articular cartilage degeneration in patients with osteonecrosis of the femoral head (ONFH) using T2 mapping magnetic resonance imaging. We reviewed 35 patients with ONFH (20 males and 15 females, mean age: 45.7 ± 12.9 years) without obvious cartilage abnormalities on plain magnetic resonance imaging (ONFH group) and 25 healthy volunteers (9 males and 16 females, mean age: 42.9 ± 5.8 years) (control group). All patients underwent T2 mapping magnetic resonance imaging after ONFH onset. The region of interest was defined as the weight-bearing portion of the articular cartilage in the femoral head and acetabulum in the coronal view. The T2 values of the articular cartilage of the acetabulum and femoral head, including necrotic and normal regions, were significantly higher in the ONFH group than those in the control group. These T2 values of the acetabulum and femoral head in Stages 3A and 2 were significantly higher in the ONFH group than those in the control group. The articular cartilage of the acetabulum and femoral head can deteriorate after the onset of ONFH, which may affect the natural history of ONFH and ONFH treatment. Our findings suggest the need for early intervention in joint preservation surgery.

Gender differences in patterns of cartilage loss: Data from the Osteoarthritis Initiative

OBJECTIVEUnderstanding gender-specific differences in patterns of cartilage loss can improve our knowledge of the pathogenesis of knee osteoarthritis (KOA) development and progression and may inform clinical trials of treatments for KOA. The goal of our observational study was to examine gender differences in patterns of cartilage loss in the central weight-bearing regions of the femur. METHODSWe measured cartilage volume change in the indexed knee of 700 subjects with Kellgren-Lawrence (KL) 1, 2, or 3 from the OAI for four follow-up periods (BL to 24mo, BL to 48mo, BL to 72mo, and BL to 96mo) using the local area cartilage segmentation (LACS) method. Briefly, the LACS method uses robust coordinate systems fixed to anatomical landmarks to measure patterns of change in cartilage volume in sub-regions using responsiveness heat maps. RESULTSWe observed a statistically significant gender difference in cartilage change in the medial femur (MF), lateral femur (LF), and medial tibia (MT). The heat maps, showed loss was primarily in the posterior central weight-bearing portion of the LF and more general in the LT and MF. Similar patterns were observed for each of the four follow-up periods. CONCLUSIONSThe LACS method was capable of illustrating gender-specific differences in patterns of cartilage loss that may offer insight into the variation of gender differences in the natural history of KOA and may be useful in evaluating the benefit of interventions for KOA.

A novel animal model of osteonecrosis of the femoral head based on 3D printing technology

BackgroundOsteonecrosis of the femoral head (ONFH) is a prevalent orthopedic condition characterized by the disruption of blood supply to the femoral head, leading to ischemia of internal tissues, subchondral bone fractures, necrosis, and eventual collapse of the weight-bearing portion of the femoral head. This condition results in severe functional impairment, pain, and even disability of the hip joint. Existing animal models of ONFH have limitations in replicating the natural disease progression accurately. Thus, there is a critical need to develop a novel animal model capable of better simulating localized pressure on the human femoral head to facilitate ONFH-related research.MethodsIn this study, we present a novel approach for modeling ONFH, which involves integrating stress factors into the modeling process through the utilization of 3D printing technology and principles of biomechanics. A total of 36 animals were randomly assigned to six groups, where they received either the novel modeling technique or the traditional hormone induction method. Subsequently, an 8-week treatment period was implemented, followed by conducting micro-CT scans and histological evaluations to assess tissue outcomes.ResultsThe study evaluated the cytotoxicity of the material used in the new model, and it was observed that the material did not exhibit any cytotoxic effects on cells. Additionally, the novel model successfully replicated the pathological features of ONFH, including femoral head collapse, along with a substantial presence of empty bone lacunae, cartilage defects, and subchondral bone fractures in the subchondral bone region.ConclusionIn conclusion, our study provides evidence that the new model shows the ability to simulate the progression of the disease, making it a valuable tool for research in this field and can contribute to the development of better treatment strategies for this debilitating condition. It holds great promise for advancing our understanding of the pathogenesis of ONFH and the potential therapeutic interventions for this challenging clinical problem.

Delayed Thoracodorsal Artery Perforator Free Flap for Calcaneal Degloving Injury Reconstruction

The thoracodorsal artery perforator (TDAP) flap has a long vascular pedicle that is ideal for lower extremity reconstruction, but it generally relies on the presence of a dominant septocutaneous perforator vessel. Surgical delay optimizes flap survival by creating relative ischemia to augment perforator vessels. In this report, we describe the use of a delayed free TDAP flap in the setting of an absent dominant perforator vessel for the reconstruction of a calcaneal degloving injury. A 22-year-old actively smoking patient with a body mass index of 33.5 presented with a nonhealing left heel wound with overlying necrotic changes after traumatic degloving injury. The entire weight-bearing portion of the calcaneal fat pad and the flanking regions were debrided. The TDAP flap was elevated, revealing three small thoracodorsal artery perforators. Given that a dominant perforator was absent, the flap was surgically delayed. Free-tissue transfer occurred 8 days later. This operation was conducted entirely in left lateral decubitus with simultaneous wound preparation and flap harvest. The flap was elevated on two perforators to elongate the pedicle's length and inset to cover exposed calcaneus and pad the heel. Six months postoperatively, the patient is doing well without flap compromise or ulceration. The TDAP flap is a versatile microsurgical tool, and surgical delay extends the utility of this flap when a dominant septocutaneous perforator is unavailable. Recipient site debridement may occur simultaneously with the TDAP delay procedure. Importantly, only one position is required for flap elevation, microsurgical anastomosis, and insetting, thus obviating intraoperative repositioning.

Effects of the location of both anterior and lateral boundaries of the necrotic lesion on collapse progression in osteonecrosis of the femoral head

BackgroundThe location of the lateral boundary of the necrotic lesion to the weight-bearing portion of the acetabulum (Type classification) is an important factor for collapse in osteonecrosis of the femoral head (ONFH). Recent studies also reported the significance of the location of the anterior boundary of the necrotic lesion on the occurrence of collapse. We aimed to assess the effects of the location of both anterior and lateral boundaries of the necrotic lesion on collapse progression in ONFH. MethodsWe recruited 55 hips with post-collapse ONFH from 48 consecutive patients, who were conservatively followed for more than one year. Using a plain lateral radiograph (Sugioka's lateral view), the location of the anterior boundary of the necrotic lesion to the weight-bearing portion of the acetabulum was classified as follows: Anterior-area I (two hips) occupying the medial one-third or less; Anterior-area II (17 hips) occupying the medial two-thirds or less; and Anterior-area III (36 hips) occupying greater than the medial two-thirds. The amount of femoral head collapse was measured by biplane radiographs at the onset of hip pain and each follow-up period, and Kaplan–Meier survival curves with collapse progression (≥1 mm) as the endpoint were produced. The probability of collapse progression was also assessed by the combination of Anterior-area and Type classifications. ResultsCollapse progression was observed in 38 of the 55 hips (69.0%). The survival rate of hips with Anterior-area III/Type C2 was significantly lower. Among hips with Type B/C1, collapse progression occurred more frequently in hips with Anterior-area III (21 of 24 hips) than in hips with Anterior-area I/II (3 of 17 hips, P < 0.0001). ConclusionsAdding the location of the anterior boundary of the necrotic lesion to Type classification was useful to predict collapse progression especially in hips with Type B/C1.

Operative management of metastatic disease of the acetabulum: review of the literature and prevailing concepts.

Metastatic disease of the periacetabular region is a common problem in orthopaedic oncology, associated with severe pain, decreased mobility, and substantial decline of the quality of life. Conservative management includes optimisation of pain management, activity modification, and radiation therapy. However, patients with destructive lesions affecting the weight-bearing portion of the acetabulum often require reconstructive surgery to decrease pain and restore mobility. The goal of surgery is to provide an immediately stable and durable construct, allowing immediate postoperative weight-bearing and maintaining functional independence for the remaining lifetime of the patient. A variety of surgical techniques have been reported, most of which are based upon cemented total hip arthroplasty, but also include porous tantalum implants and percutaneous cementoplasty. This review discusses the various reconstructive concepts and options, including their respective indications and outcome. A reconstructive algorithm incorporating different techniques and strategies based upon location and quality of remaining bone is also presented.

Investigating the subchondral trabecular bone microstructure in patients with osteonecrosis of the femoral head using multi-detector row computed tomography.

To analyse the microstructural changes of subchondral trabecular bone in patients with osteonecrosis of the femoral head (ONFH) using multi-detector row computed tomography (MDCT). We retrospectively investigated 76 hips in 50 patients diagnosed with ONFH between 2017 and 2021. Groups 1, 2, 3, and 4 comprised hips without ONFH, ONFH without femoral head collapse (FHC), ONFH with mild collapse (<2 mm), and ONFH with severe collapse (>2 mm), respectively. All patients underwent MDCT, and the subchondral trabecular bone microstructure was assessed. Regions of interests were set at the lateral boundary of the femoral head necrotic lesion and centre of the acetabular weight-bearing portion. In both the femoral head and the acetabular regions, there were significant differences in Groups 2 and 3 compared to Group 1, with increased volumetric bone mineral density and apparent bone volume fraction, and more plate-like with increased connectivity, indicating that osteosclerotic changes were occurring. In both the femoral head and the acetabular regions, osteosclerotic changes of subchondral trabecular bone microstructure were present before FHC.

State of the Art : Current Acetabulum Fracture Management

The annual incidence of acetabulum fractures is estimated to be 8.1 per 100.000 patients. In young adults, high energy trauma is the primary mechanism, but in the elderly, low energy trauma is the primary mechanism. Comorbidities, poor bone quality, and delayed presentation are all linked to a poor outcome. From diagnosis to treatment, the goal of this study is to describe the required procedures in reaching a satisfactory result.It is essential to be able to correctly classify acetabular fractures using the Joudet and Letournel classifications, especially when planning definitive therapy. Non-surgical and operative treatment methods are available for acetabulum fractures. All acetabulum fractures that result in hip joint instability and/or incongruity require surgical treatment. Although the prognosis is lower than in younger patients, Open Reduction Internal Fixation (ORIF) remains the mainstay of therapy for most elderly acetabular fractures. Central fracture dislocation of the hip with medial migration of the quadrilateral plate is common in patients with both column, transverse, T-shaped, and anterior column-posterior hemi-transverse fractures. Failure to repair the quadrilateral plate will result in an incongruent hip and a poor outcome since it has a thin medial wall that fractures with less force than the superior weight-bearing portion of the acetabulum.The goals of postoperative care are to maximize the patient's function, allow a quick return to function, and detect early problems. Complications with acetabulum fractures might occur with any treatment option. Post-traumatic arthritis is the most common complications, followed by Deep Vein Thrombosis (DVT), heterotrphic ossification, infection, and iatrogenic sciatic nerve damage.

Testing Hypoxia in Pig Meniscal Culture: Biological Role of the Vascular-Related Factors in the Differentiation and Viability of Neonatal Meniscus.

Menisci play an essential role in shock absorption, joint stability, load resistance and its transmission thanks to their conformation. Adult menisci can be divided in three zones based on the vascularization: an avascular inner zone with no blood supply, a fully vascularized outer zone, and an intermediate zone. This organization, in addition to the incomplete knowledge about meniscal biology, composition, and gene expression, makes meniscal regeneration still one of the major challenges both in orthopedics and in tissue engineering. To overcome this issue, we aimed to investigate the role of hypoxia in the differentiation of the three anatomical areas of newborn piglet menisci (anterior horn (A), central body (C), and posterior horn (P)) and its effects on vascular factors. After sample collection, menisci were divided in A, C, P, and they were cultured in vitro under hypoxic (1% O2) and normoxic (21% O2) conditions at four different experimental time points (T0 = day of explant; T7 = day 7; T10 = day 10; T14 = day 14); samples were then evaluated through immune, histological, and molecular analyses, cell morpho-functional characteristics; with particular focus on matrix composition and expression of vascular factors. It was observed that hypoxia retained the initial phenotype of cells and induced extracellular matrix production resembling a mature tissue. Hypoxia also modulated the expression of angiogenic factors, especially in the early phase of the study. Thus, we observed that hypoxia contributes to the fibro-chondrogenic differentiation with the involvement of angiogenic factors, especially in the posterior horn, which corresponds to the predominant weight-bearing portion.

Review of Quantitative Knee Articular Cartilage MR Imaging.

Osteoarthritis (OA) is one of the most prevalent disorders in today’s society, resulting in significant socio-economic costs and morbidity. MRI is widely used as a non-invasive imaging tool for OA of the knee. However, conventional knee MRI has limitations to detect subtle early cartilage degeneration before morphological changes are visually apparent. Novel MRI pulse sequences for cartilage assessment have recently received increased attention due to newly developed compositional MRI techniques, including: T2 mapping, T1rho mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), sodium MRI, diffusion-weighted imaging (DWI)/ diffusion tensor imaging (DTI), ultrashort TE (uTE), and glycosaminoglycan specific chemical exchange saturation transfer (gagCEST) imaging. In this article, we will first review these quantitative assessments. Then, we will discuss the variations of quantitative values of knee articular cartilage with cartilage layer (depth)- and angle (regional)-dependent approaches. Multiple MRI sequence techniques can discern qualitative differences in knee cartilage. Normal articular hyaline cartilage has a zonal variation in T2 relaxation times with increasing T2 values from the subchondral bone to the articular surface. T1rho values were also higher in the superficial layer than in the deep layer in most locations in the medial and lateral femoral condyles, including the weight-bearing portion. Magic angle effect on T2 mapping is clearly observed in the both medial and lateral femoral condyles, especially within the deep layers. One of the limitations for clinical use of these compositional assessments is a long scan time. Recent new approaches with compressed sensing (CS) and MR fingerprinting (MRF) have potential to provide accurate and fast quantitative cartilage assessments.

Preoperative T2 mapping MRI of articular cartilage values predicts postoperative osteoarthritis progression following rotational acetabular osteotomy.

Rotational acetabular osteotomy (RAO) has been reported to be effective in improving symptoms and preventing osteoarthritis (OA) progression in patients with mild to severe develomental dysplasia of the hip (DDH). However, some patients develop secondary OA even when the preoperative joint space is normal; determining who will progress to OA is difficult. We evaluated whether the preoperative cartilage condition may predict OA progression following surgery using T2 mapping MRI. We reviewed 61 hips with early-stage OA in 61 patients who underwent RAO for DDH. They underwent preoperative and five-year postoperative radiological analysis of the hip. Those with a joint space narrowing of more than 1 mm were considered to have 'OA progression'. Preoperative assessment of articular cartilage was also performed using 3T MRI with the T2 mapping technique. The region of interest was defined as the weightbearing portion of the acetabulum and femoral head. There were 16 patients with postoperative OA progression. The T2 values of the centre to the anterolateral region of the acetabulum and femoral head in the OA progression cases were significantly higher than those in patients without OA progression. The preoperative T2 values in those regions were positively correlated with the narrowed joint space width. The receiver operating characteristic analysis revealed that the T2 value of the central portion in the acetabulum provided excellent discrimination, with OA progression patients having an area under the curve of 0.858. Furthermore, logistic regression analysis showed T2 values of the centre to the acetabulum's anterolateral portion as independent predictors of subsequent OA progression (p < 0.001). This was the first study to evaluate the relationship between intra-articular degeneration using T2 mapping MRI and postoperative OA progression. Our findings suggest that preoperative T2 values of the hip can be better prognostic factors for OA progression than radiological measures following RAO. Cite this article: Bone Joint J2021;103-B(9):1472-1478.

Biomechanical effect of intertrochanteric curved varus osteotomy on stress reduction in femoral head osteonecrosis: a finite element analysis.

BackgroundIntertrochanteric curved varus osteotomy (CVO) has been widely used to remove the necrotic bone away from the weight-bearing portion in the treatment of osteonecrosis of the femoral head (ONFH). However, whether all types of necrosis will benefit from CVO, in terms of the stress level, the effect of different center-edge (CE) angles of acetabulum on stress distribution of necrosis after CVO, and the relationship between the intact ratio and the stress of necrosis, has never been addressed. The purpose of the study was to evaluate the influence of CVO on the stress reduction in necrotic bone using a finite element analysis (FEA) with different CE angles.MethodsCVO finite element models of the hip joint were simulated with a lesion of 60°. The osteotomy angles were divided into four configurations (15°, 20°, 25°, and 30°), and three types (A, B, and C1) of lesions were established based on the Japanese Investigation Committee (JIC) classification. In addition, two CE angles (18° and 33°) of acetabulum were considered. The maximum and mean von Mises stress were analyzed in terms of the necrotic bone by a physiological loading condition. Moreover, the correlation of the intact ratio measured in 3D and the stress distribution after CVO was analyzed.ResultsStress reduction was obtained after CVO. For type B, the CVO angle was 20° (0.61 MPa), and for type C1, the CVO angle was 30° (0.77 MPa), if the mean stress level was close to type A (0.61 MPa), as a standard. The maximum and mean von Mises stress were higher in the CE angle of 18°models, respectively. The intact ratio measured in 3D had a good negative correlation with stress after CVO and had more influence on stress distribution in comparison to other geometric parameters.ConclusionsFor making decisions about the biomechanics of CVO, a CVO angle of > 20° was recommended for type B and > 30° was safe for type C1. The risk of progressive collapse was increased in the insufficient situation of the weight-bearing portion after CVO. The intact ratio could provide information about clinical outcomes and stress distribution after CVO.

Modifications de la morphologie du fémur proximal après ostéotomie trans-trochantérienne de retournement postérieur pour nécrose de la tête fémorale : simulation tridimensionnelle

BackgroundTranstrochanteric posterior rotational osteotomy (PRO) is one of the joint-preserving surgeries for osteonecrosis of the femoral head. In general, postoperative femoral neck-shaft varus realignment is planned to obtain a sufficient intact articular surface of the femoral head in the weight-bearing portion. Unlike anterior rotational osteotomy, PRO allows for more than 90° rotation of the femoral head, resulting in more complicated morphology. However, little is known about the potential risk of postoperative femoral retroversion after PRO. This simulation study aims: 1) to assess whether postoperative femoral neck-shaft varus realignment can coexist with preserved femoral anteversion after PRO, 2) and whether postoperative proximal femoral morphology could be predicted with approximation equations. HypothesisHigh degree (>90°) PRO is favorable for femoral neck-shaft varus realignment but unfavorable for maintaining postoperative femoral anteversion. Materials and methodsPRO was simulated by using CT data from 10 hips in 10 healthy volunteers. During simulation, the intertrochanteric osteotomy plane was determined three-dimensionally based on anteroposterior-view line (the osteotomy line on anteroposterior view) and lateral-view line (the osteotomy line on lateral view). By changing either the angle of anteroposterior-view line or lateral-view line, we simulated 90°, 110°, 130° and 150° PRO. To clarify the effects of various posterior rotation angles on postoperative proximal femoral morphology, we made simplified PRO models through changing only the posterior rotation angle. ResultsIn the 90°, 110°, 130° and 150° PRO models, the vertically inclined angle of anteroposterior-view line showed a significant positive correlation with femoral neck-shaft varus realignment (90° PRO, r=0.90; 110° PRO, r=0.95; 130° PRO, r=0.97; 150° PRO, r=0.99), while a significant negative correlation with postoperative femoral anteversion angle (90° PRO, r=−0.97; 110° PRO, r=−0.95; 130° PRO, r=−0.92; 150° PRO, r=−0.7). Likewise, the posteriorly tilted angle of lateral-view line showed a significant negative correlation with both femoral neck-shaft varus realignment (90° PRO, r=−0.81; 110° PRO, r=−0.81; 130° PRO, r=−0.79; 150° PRO, r=−0.72) and postoperative femoral anteversion angle (90° PRO, r=−0.90; 110° PRO, r=−0.89; 130° PRO, r=−0.92; 150° PRO, r=−0.88). In the simplified PRO models, the posterior rotation angle showed a significant positive correlation with femoral neck-shaft varus realignment (r=0.33), while a significant negative correlation with postoperative femoral anteversion angle (r=−0.76). The approximation equations for predicting the proximal femoral morphology after PRO were validated. DiscussionsIt was confirmed that high-degree PRO (>90°) is favorable for femoral neck-shaft varus realignment but works against preserving femoral anteversion. With the approximation equations developed in the current study, surgeons could examine the feasibility of PRO based on postoperative femoral anteversion. In terms of hip joint function and subsequent total hip arthroplasty, excessive deformities including femoral retroversion and severe varus deformity could be avoided. Level of evidenceIV; case series without control group.

Proximal femoral morphology after transtrochanteric posterior rotational osteotomy for osteonecrosis of the femoral head: A three-dimensional simulation study

BackgroundTranstrochanteric posterior rotational osteotomy (PRO) is one of the joint-preserving surgeries for osteonecrosis of the femoral head. In general, postoperative femoral neck-shaft varus realignment is planned to obtain a sufficient intact articular surface of the femoral head in the weight-bearing portion. Unlike anterior rotational osteotomy, PRO allows for more than 90° rotation of the femoral head, resulting in more complicated morphology. However, little is known about the potential risk of postoperative femoral retroversion after PRO. This simulation study aims: 1) to assess whether postoperative femoral neck-shaft varus realignment can coexist with preserved femoral anteversion after PRO, 2) and whether postoperative proximal femoral morphology could be predicted with approximation equations. HypothesisHigh degree (>90°) PRO is favourable for femoral neck-shaft varus realignment, but unfavourable for maintaining postoperative femoral anteversion. Materials and methodsPRO was simulated by using CT data from 10 hips in 10 healthy volunteers. During simulation, the intertrochanteric osteotomy plane was determined three-dimensionally based on anteroposterior-view line (the osteotomy line on anteroposterior view) and lateral-view line (the osteotomy line on lateral view). By changing either the angle of anteroposterior-view line or lateral-view line, we simulated 90°, 110°, 130° and 150° PRO. To clarify the effects of various posterior rotation angles on postoperative proximal femoral morphology, we made simplified PRO models through changing only the posterior rotation angle. ResultsIn the 90°, 110°, 130° and 150° PRO models, the vertically inclined angle of anteroposterior-view line showed a significant positive correlation with femoral neck-shaft varus realignment (90° PRO, r=0.90; 110° PRO, r=0.95; 130° PRO, r=0.97; 150° PRO, r=0.99), while a significant negative correlation with postoperative femoral anteversion angle (90° PRO, r=−0.97; 110° PRO, r=−0.95; 130° PRO, r=−0.92; 150° PRO, r=−0.7). Likewise, the posteriorly tilted angle of lateral-view line showed a significant negative correlation with both femoral neck-shaft varus realignment (90° PRO, r=−0.81; 110° PRO, r=−0.81; 130° PRO, r=−0.79; 150° PRO, r=−0.72) and postoperative femoral anteversion angle (90° PRO, r=−0.90; 110° PRO, r=−0.89; 130° PRO, r=−0.92; 150° PRO, r=−0.88). In the simplified PRO models, the posterior rotation angle showed a significant positive correlation with femoral neck-shaft varus realignment (r=0.33), while a significant negative correlation with postoperative femoral anteversion angle (r=−0.76). The approximation equations for predicting the proximal femoral morphology after PRO were validated. DiscussionsIt was confirmed that high-degree PRO (>90°) is favourable for femoral neck-shaft varus realignment, but works against preserving femoral anteversion. With the approximation equations developed in the current study, surgeons could examine the feasibility of PRO based on postoperative femoral anteversion. In terms of hip joint function and subsequent total hip arthroplasty, excessive deformities including femoral retroversion and severe varus deformity could be avoided. Level of evidenceIV; case series without control group.

Can an OA Knee Brace Effectively Offload the Medial Condyle? An In Vivo Fluoroscopic Study

BackgroundPrevious studies evaluating the effectiveness of OA offloading knee braces focused on qualitative results. The objective of this study was to analyze the effectiveness of an off-loading knee brace with respect to in vivo three-dimensional knee kinematics to quantitatively measure the changes in medial joint space and relative bone alignment when wearing the brace. MethodsTwenty subjects diagnosed with medial compartmental joint space narrowing and varus deformity due to OA were recruited. During fluoroscopic surveillance, subjects performed normal gait on a treadmill with and without the brace. Images were sequenced at heel-strike and mid-stance during the weight-bearing portion of gait. 3D-to-2D image registration was performed on each subject using 3D bone models derived from CT segmentation and 3D ultrasound scans. ResultsMedial joint space was to increase when the brace was applied in all subjects (1.6 ± 0.7 mm at heel-strike, 1.6 ± 0.8 mm at mid-stance) and was statistically significant (P < .001). It was also found that sixteen of the twenty subjects experienced a medial joint space increase of more than 1.0 mm during heel-strike while thirteen of twenty experienced this change at mid-stance. While wearing the brace, over half of the subjects experienced a valgus correction to their alignment. ConclusionsAll subjects in this study experienced a positive change in the medial joint space when wearing the offloading knee brace. In addition, many subjects also saw joint space values representative of previously documented, nonosteoarthritic subjects and valgus changes in bone alignment more akin to the normal knee.

Below-the-Knee Amputation With Targeted Muscle Reinnervation: Operative Technique and Technical Pearls of an Interfascicular Superficial Peroneal Nerve Targeted Muscle Reinnervation

INTRODUCTION: Targeted muscle reinnervation (TMR) is a nerve transfer technique by which the severed ends of sensory nerves are transferred to expendable donor motor nerves to minimize pain. TMR has successfully been used to reduce residual limb and phantom limb pain in patients with upper and lower extremity amputations. For patients with below-the-knee amputations (BKAs), the tibial nerve and superficial peroneal nerve (SPN) are the most common sensory nerves addressed with TMR. Although the tibial nerve coaptation is well-protected by the deep posterior musculature, the SPN coaptation is commonly positioned at the weight-bearing portion of the stump without significant soft tissue padding. This study details a novel interfascicular SPN TMR technique performed through a proximal incision at the fibular head. TECHNIQUE: TMR performed primarily at time of BKA is offered to all patients preoperatively to prophylactically reduce pain. TMR is also offered secondarily to patients who develop severe neuroma or phantom limb pain after their amputation. When performed primarily, TMR is performed on the SPN and tibial nerve. When performed secondarily, TMR is performed on the involved nerves based on clinical exam. The SPN TMR is performed through an approach to the common peroneal nerve (CPN) at the fibular head. Accessing the CPN at this level allows for complete decompression of the CPN through the peroneal tunnel. An internal neurolysis is performed, and a nerve stimulator is used to map the motor fascicles to identify an expendable target. The extensor digitorum longus is preferentially selected since it is not critical to tibial padding. The SPN is then translocated from the distal wound into the peroneal tunnel incision and an antegrade nerve transfer is performed to the motor target, typically with a close size match (Video). RESULTS: This technique for primary TMR for BKAs was performed in 109 patients over a 2-year period from January 1, 2018 to December 31, 2019. The SPN was transferred to the extensor digitorum longus 78.5% of the time, peroneus brevis 9.3%, redundant branch of tibialis anterior 6.5%, and peroneus longus 5.6%. The tibial nerve was transferred to the tibialis posterior 66.7% of the time, soleus 10.0%, flexor digitorum longus 8.3%, flexor hallucis longus 8.3%, and unspecified muscle of the deep flexor compartment 6.7%. No primary DPN, sural, or saphenous TMRs were performed. There were no added surgical complications attributable to the TMR portion of the case: no surgical site infections at the fibular head incision or reoperation for seromas or hematomas. If patients developed pain in the saphenous or sural distributions a secondary TMR was performed, but this was only required in 2 patients. CONCLUSIONS: TMR has been demonstrated to greatly improve amputees’ pain and ambulation following a major lower extremity amputation. This article provides insight into the technical pearls of the unique interfascicular SPN TMR, which places the coaptation away from the weight-bearing stump and allows for a close size match. This technique has been used with excellent clinical outcomes and no procedure-specific complications in over 100 patients.

Ipsilateral Osteochondritis Dissecans-like Distal Femoral Lesions in Children with Blount Disease: Prevalence and Associated Findings.

ABSTRACTPurposeOur goal was to assess the prevalence of ipsilateral distal femoral osteochondritis dissecans (OCD)-like lesions in children with Blount disease, including factors associated with this finding.Materials and methodsCharacteristics of patients with an OCD-like lesion on an imaging study [(X-ray and/or magnetic resonance imaging (MRI)] were compared with those without such a finding.ResultsOver a 12-year period, 6/63 (10%) skeletally immature patients (9/87 limbs) with Blount disease had an OCD-like lesion visible on plain radiographs. Based on available MRI, 7/37 (19%) patients or 10/53 (19%) limbs had an OCD-like distal femoral lesion. All lesions were noted in the posterior third of the weight-bearing portion of the medial femoral condyle with intact overlying articular cartilage. All patients with OCD-like lesions were followed for an average of 1.9 years (range: 1–2.6 years), and complete radiographic resolution of lesion was noted in 7/9 limbs (78%). There was no association of the presence of OCD-like lesion with early- vs late-onset disease, gender, age at imaging, laterality, magnitude of deformity [mean mechanical axis deviation (MAD) 63.3 vs 71.9 mm], mean mechanical lateral distal femoral angle (mLDFA; 91.3 vs 89.7°), and mean medial proximal tibial angle (MPTA; 71.7 vs 71.8°). Children with an OCD-like lesion tended to have a lower mean body mass index (BMI; 21 vs 36, p = 0.003).ConclusionThe overall prevalence of OCD-like lesions in the medial femoral condyle in children with Blount disease lesions is 10% using plain radiographs and at least 19% on MRI. Based on the numbers available, we were unable to demonstrate any associations between the presence of such lesions and the patient’s age, gender, or magnitude of varus deformity. Further research is needed to fully ascertain the aetiology and natural history of these benign appearing osteochondral imaging findings in children with Blount disease. Our current data support that these lesions do resolve with time and that no surgical intervention targeted at the femoral OCD-like lesion is warranted.Level of evidenceDiagnostic study Level III.How to cite this articleEdobor-Osula F, Wenokor C, Bloom T, et al. Ipsilateral Osteochondritis Dissecans-like Distal Femoral Lesions in Children with Blount Disease: Prevalence and Associated Findings. Strategies Trauma Limb Reconstr 2019;14(3):121–125.