Femoral Reconstruction Research Articles

Proximal Femur Megaprostheses in Orthopedic Oncology: Evaluation of a Standardized Post-operative Rehabilitation Protocol.

Reconstructions of the proximal femur after massive resections represent one of the main challenges in orthopedic oncology. Among the possible treatments, megaprostheses represent one of the most used and reliable reconstructive approaches. Although literature about their outcomes has flourished through the last decades, a consensus rehabilitative treatment is still far from being established. We evaluated the functional results of all our oncologic cases treated between 2016 and 2022 that could follow our standardized post-operative rehabilitative approach, consisting in progressive hip mobilization and early weight-bearing. Twenty-two cases were included in our study. On average, their hospitalization lasted 15.1days. The seated position was achieved on average within 3.7days after surgery, the standing position reached 5.4 after surgery, while assisted deambulation was started 6.4days after surgery. After a mean post-operative follow-up of 44.0months, our patients' mean MSTS score was 23.2 (10-30). Our data suggested a statistically significant inverse linear correlation between post-operative functionality and patients' age, resection length, and the start of deambulation. A correct rehabilitation, focused on early mobilization and progressive weight-bearing, is crucial to maximize patients' post-operative functional outcomes.

Polydioxanone Enhances Bone Regeneration After Resection and Reconstruction of Rat Femur with rhBMP2.

The aim of this study was to assess the bone regeneration potential of a polydioxanone (PDO) scaffold together with recombinant human bone morphogenetic protein-2 (rhBMP-2) for the reconstruction of large bone defect. In total, 24 male rats (6 months old) were subjected to bilateral femoral stabilization using titanium plates to create a 2 mm gap, and reconstruction using rhBMP-2 (Infuse®; 3.25 μg). The bone defects were covered with PDO (PDO group), or with titanium mesh (Ti group). Animals were euthanized on days 14 and 60. Simultaneously, 16 rats received PDO and Ti in their dorsum for the purpose of biocompatibility analysis at 3, 5, 7, and 10 days postoperatively. X-ray densitometry showed a higher density in the PDO group on day 14. On day 60, coverage of the bone defect with PDO showed a larger quantity of newly formed bone than that found for the Ti group, a lower inflammatory infiltrate value, and a more significant number of blood vessels on day 14. By immunohistochemical assessment, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) showed higher labeling on day 14 in the PDO group. On day 60, bone morphogenetic protein-2 (BMP-2) showed higher labeling in the PDO group, whereas Ti showed higher labeling for osteoprotegerin, nuclear factor kappa B ligand-activating receptor, RUNX2, and OCN. Furthermore, biocompatibility analysis showed a higher inflammatory response in the Ti group. The PDO scaffold enhanced bone regeneration when associated with rhBMP-2 in rat femur reconstruction. Impact statement Regeneration of segmental bone defects is a difficult task, and several techniques and materials have been used. Recent advances in the production of synthetic polymers, such as polydioxanone (PDO), produced by three-dimensional printing, have shown distinct characteristics that could improve tissue regeneration even in an important bone defect. The present preclinical study showed that PDO membranes used as scaffolds to carry recombinant human bone morphogenetic protein-2 (rhBMP-2) improved bone tissue regeneration by more than 8-fold when compared with titanium mesh, suggesting that PDO membranes could be a feasible and useful material for use in guided bone regeneration. (In English, viable is only used for living creatures capable of sustaining life.

SSDL-an automated semi-supervised deep learning approach for patient-specific 3D reconstruction of proximal femur from QCT images.

Deep Learning (DL) techniques have recently been used in medical image segmentation and the reconstruction of 3D anatomies of a human body. In this work, we propose a semi-supervised DL (SSDL) approach utilizing a CNN-based 3D U-Net model for femur segmentation from sparsely annotated quantitative computed tomography (QCT) slices. Specifically, QCT slices at the proximal end of the femur forming ball and socket joint with acetabulum were annotated for precise segmentation, where a segmenting binary mask was generated using a3D U-Net model to segment the femur accurately. A total of 5474 QCT slices were considered for training among which 2316 slices were annotated. 3D femurs were further reconstructed from segmented slices employing polynomial spline interpolation. Both qualitative and quantitative performance of segmentation and 3D reconstruction were satisfactory with more than 90% accuracy achieved for allof the standardperformance metrics considered. The spatial overlap index and reproducibility validation metric for segmentation-Dice Similarity Coefficient was 91.8% for unseen patients and 99.2% for validated patients. An average relative error of 12.02% and 10.75% for volume and surface area, respectively, were computed for 3D reconstructed femurs. The proposed approach demonstrates its effectiveness in accurately segmenting and reconstructing 3D femur from QCT slices.

Three-dimensional reconstruction of femur based on Laplace operator and statistical shape model

Reconstructing three-dimensional (3D) models from two-dimensional (2D) images is necessary for preoperative planning and the customization of joint prostheses. However, the traditional statistical modeling reconstruction shows a low accuracy due to limited 3D characteristics and information loss. In this study, we proposed a new method to reconstruct the 3D models of femoral images by combining a statistical shape model with Laplacian surface deformation, which greatly improved the accuracy of the reconstruction. In this method, a Laplace operator was introduced to represent the 3D model derived from the statistical shape model. By coordinate transformations in the Laplacian system, novel skeletal features were established and the model was accurately aligned with its 2D image. Finally, 50 femoral models were utilized to verify the effectiveness of this method. The results indicated that the precision of the method was improved by 16.8%-25.9% compared with the traditional statistical shape model reconstruction. Therefore, the method we proposed allows a more accurate 3D bone reconstruction, which facilitates the development of personalized prosthesis design, precise positioning, and quick biomechanical analysis.

A case report of early detection of rare femoral shaft bone metastasis in a penis cancer patient

Background. Bone metastasis is very common in the advanced stage of numerous carcinomas. In penile carcinoma, lymph nodes metastasis is somehow common but it is very rare reported to be secondary from penile cancer. till the date, there are only few cases of penis carcinoma reported bone metastasis in literature worldwide.Case Presentation. Herein, We presented a 51-year-old Nepalese male with squamous cell carcinoma of penis. computed tomography (ct) scan of the patient revealed that there was carcinoma involving glans penis and precure with bilateral external & internal inguinal lymphadenopathies. After then, the patient was under gone for partial penectomy and bilateral inguinal lymphadenectomy and complete 6-cycle chemotherapy. After one year of treatment, patient developed thigh pain and headache and he advised to have magnetic Resonance imaging (mRi) of brain, 99mTc-MDP whole body bone scan and ct scan of pelvis and thigh. The examination report reveals that there was a sclerotic change in vertex of skull bone and moderate 99mTc-MDP uptake in right proximal shaft of femur just below the neck d/d metastasis. The histopathological examination of the true cut biopsy taken from the lesion of the femur showed metastatic keratinizing squamous cell carcinoma which is rare case of femoral shaft bone metastasis secondary from penile carcinoma. Then patient was sent for surgical reconstruction of femur. Based on the case studies review femur shaft bone metastasis from penile cancer is extremely rare.Conclusion. The best of our knowledge; this is the first early detected bone metastases to shaft of the femur in a patient with penile cancer. early diagnosis helps to radical treatment as well as palliative treatment. surgery is the preferred option of the treatments, especially for metastatic foci in the long bones.

Effect of concomitant deformity correction on patient outcomes following femoral (OTA type 32) nonunion repair

IntroductionThe purpose of this study was to determine what effect, if any, concomitant deformity correction has on outcomes following femoral nonunion repair. Methods605 consecutive patients who presented to our center with a long bone nonunion treated by one of 3 surgeons was queried. Sixty-two patients (10 %) with complete follow up were treated for a fracture nonunion following a Type 32 femur fracture (subtrochanteric, femoral shaft or distal third metaphysis) over an 11-year period. Twenty of these patients underwent a deformity correction (DC)–angular, rotational, or a combination of both–as part of their femoral reconstruction. Patient demographics and initial injury information was reviewed and compared. Outcomes including radiographic healing, time to union, postoperative complications, patient reported pain scores, and functional outcome scores using the Short Musculoskeletal Functional Assessment (SMFA) were recorded. Patients with and without deformity correction were analyzed and compared using independent T-tests and Chi-Square tests. ResultsCompared to the non-deformity correction (NDC) cohort, the DC cohort demonstrated a worse complication profile. Notably, the DC cohort had longer time to union (11.6 ± 7.3 months vs 7.6 ± 8.5 months, P = 0.042), reported significantly higher VAS pain scores at 1-year post-op (4.2 ± 2.8 vs 2.3 ± 2.6, P = 0.007), experienced more complications (25 % vs 4.8 %, P = 0.019), and had a higher rate of secondary procedures (30 % vs 4.8 %, P = 0.006). The DC patients reported less improvement in functional capability as displayed by a smaller average improvement in initial and final SMFA scores (P = 0.042) There was no difference in ultimate bone healing (P = 0.585), baseline SMFA (P = 0.294), and latest SMFA (P = 0.066). ConclusionDeformity correction, if needed as part of femoral nonunion repair, is associated with an increased time to heal, greater rate of complications and diminished improvement of functionality. Eventual healing and patient reported outcomes were similar whether a deformity correction is necessary or not. Level of EvidenceIII

Revision total hip arthroplasty with custom-made hip implant for Paprosky type IV femoral bone loss

Introduction Replacement of extensive Paprosky type IIIB and type IV bone loss is a challenge in revision total hip arthroplasty (THA).The purpose was to demonstrate the possibility of femoral reconstruction in proximal femur bone loss using a custom-made implant for revision THA.Material and methods We report a case of a 72-year-old patient with an extensive Paprosky type IV femoral defect, which was replaced using a custom-made modular component.Results The femoral defect was successfully augmented with a custom-made modular component, and the hip function was restored. The locking mechanism of the constrained system failed at 6 months with the joint remained stable. The patient could ambulate with additional support. VAS, HHS and HOOS scores measured before and after 2 years showed positive dynamics.Discussion Paprosky type IIIB and type IV defects are a challenge for revision hip arthroplasty. There is a variety of surgical options with outcomes being ambiguous. Modular and monoblock tapered stems, the technique of impacted bone graft have been reported to have excellent results in revision THA with Paprosky type III and IV defects. A custom-made femoral component was developed based on the principle of modular stems. Joint stability is a concomitant problem with a severe bone defect that can be addressed with a double mobility or constrained system. Both methods are associated with a sufficient number of complications.Conclusion Replacement of a Paprosky type IV femoral defect with a custom-made modular component demonstrated satisfactory outcomes at a two‑year follow-up. The patient had no complaints, could ambulate unassisted using an elbow crutch and positively evaluated the result of treatment.

Long-term effectiveness of uncemented allograft-prosthesis composite for reconstruction of bone defects after proximal femur tumor resection

To investigate the long-term effectiveness of uncemented allograft-prosthesis composite (APC) for reconstruction of bone defects after proximal femur tumor resection. Between June 2007 and March 2014, 21 patients who underwent uncemented APC reconstruction of proximal femur after tumor resection were retrospectively evaluated. There were 9 males and 12 females with an average age of 33.2 years (range, 19-54 years). There were 9 cases of giant cell tumor of bone, 5 cases of osteosarcoma, 4 cases of osteoblastic osteosarcoma, 2 cases of chondrosarcoma, and 1 case of undifferentiated pleomorphic sarcoma. Thirteen cases of benign bone tumors were all classified as stage 3 by Enneking staging; and 8 cases of malignant bone tumors were classified as grade ⅡB in 7 cases and grade ⅡA in 1 case according to the American Joint Committee on Cancer (AJCC) staging system. Among them, 7 patients underwent reoperation after recurrence, and the rest were primary operations; 8 patients presented with pathological fractures. The preoperative Harris hip score (HHS) and American Musculoskeletal Tumor Society (MSTS) score was 40 (30, 49) and 9.1±3.5, respectively. The length of osteotomy was 80-154 mm, with an average of 110 mm. At 1 year after operation and last follow-up, HHS and MSTS scores were utilized to evaluate the function of hip joint; the gluteus medius strength score was used to evaluation of the hip abduction function. Image examinations were taken at 1, 3, 6, 9, and 12 months after operation and every year thereafter to assess the union of allograft-host bone interfaces. Intra- and post-operative complications were also recorded. All patients were followed up 84-163 months (mean, 123.5 months). At 1 year after operation and last follow-up, the HHS and MSTS scores significantly improved when compared with the preoperative scores ( P<0.05). However, there was no significant difference in the HHS score, MSTS score, and gluteus medius strength score between the two time points after operation ( P>0.05). Image examination showed that all allograft-host bone interfaces achieved union after 5-10 months (mean, 7.6 months). At last follow-up, all patients had bone resorption, including 11 severe cases, 4 moderate cases, and 6 mild cases; the bone resorption sites included Gruen 1, 2, and 7 regions. Complications included 10 fractures and 1 prosthetic fracture. Local recurrence occurred in 3 patients and pulmonary metastasis in 3 patients. Uncemented APC is a reliable method for the reconstruction of bone defects after proximal femur tumor resection. It has the good long-term effectiveness and possesses obvious advantages in the union at the bone-bone surface.

Both Acetabular and Femoral Reconstructions With Impaction Bone Grafting in Revision Total Hip Arthroplasty: Case Series and Literature Review

BackgroundExtensive bone loss on femur and acetabulum posed a big challenge to orthopedists in total hip revision surgeries. Impaction bone grafting (IBG) as a valuable bone preservation technique could effectively address this problem. Either IBG revision on the femoral or acetabular side was well studied, while its use on both sides in one operation was not. The aim of this study is to present the outcomes of IBG on both femoral and acetabular sides at first-time hip revision. MethodsWe retrospectively reviewed 8 patients (mean follow-up of 5.8 years) undergoing first-time revision with IBG on both acetabular and femoral sides at our institution. The Paprosky classification system was used to classify bone defects. Freeze-dried allografts and cemented prostheses were used in all patients. Postoperative complications and rerevision rates were reported. ResultsFive patients presented a Paprosky type IIC acetabular defect, 3 with a type IIIB, IIIA, and IIC defect, respectively. Three patients presented with a type IV femoral defect, 3 with a type IIIB defect, and 2 with a type II defect. Two patients developed complications, while one had an intraoperative femoral fracture and one had delayed wound healing. At the latest follow-up, no patient had rerevisions or operations related to the prosthesis. ConclusionsIBG in combination with cemented prosthesis is a profitable biological reconstruction revision technique that could provide satisfying midterm outcomes. We first propose the use of blood clots mixed with bone grafts for potential bone incorporation enhancement, while its specific effects need to be verified in further studies.

Three-dimensional digital technology-assisted precise tumor resection and reconstruction of the femoral trochanter and postoperative functional recovery: a retrospective study

BackgroundThe trochanter of the femur is a common site for bone tumors. However, locating the specific boundary of bone tumor infiltration and determining the surgical method can be challenging. The objective of this study was to review the diagnosis, treatment, and surgical outcomes of patients with tumors or tumor-like changes in the femoral trochanter after computer-assisted precise tumor resection and hip-preserving reconstruction of the trochanter. MethodsFrom January 2005 to September 2020, 11 patients with trochanteric tumors (aged: 18–53 years; six males and five females) were treated in Guangzhou First People's Hospital. The cases included aneurysmal bone cyst (n = 1), giant cell tumor of bone (n = 2), fibrous histiocytoma of bone (n = 1), endochondroma (n = 1), and fibrous dysplasia of bone (n = 6). For patients with trochanteric tumors, computed tomography and magnetic resonance imaging scanning were performed before operation to obtain two-dimensional image data of the lesion. A three-dimensional digital model of bilateral lower limbs was reconstructed by computer technology, the boundary of tumor growth was determined by computer simulation, the process of tumor resection and reconstruction was simulated, and the personalized guide template was designed. During the operation, the personalized guide plate guided the precise resection of the tumor, and the allogeneic bone was trimmed to match the shape of the bone defect. ResultsAll 11 patients underwent accurate resection of the tumor or tumor-like lesion and reconstruction of the hip. In eight cases, the lesion was confined to the trochanter, which was fixed with large segment allogeneic bone, autologous iliac bone, and proximal femoral anatomic plate. In three cases, allogeneic bone, autologous iliac bone, and femoral reconstruction nail were used to fix the tumor under the trochanter. Postoperative X-ray examination showed that the repair and reconstruction of the bone defect was effective, and callus bridging between the allogenic bone and autogenous bone was observed 6 months after operation. All patients recovered their walking function 3–6 months after operation. The duration of the follow-up period ranged from 6 months to 6 years. A patient experienced recurrence of endochondroma; pathological examination revealed chondrocytic sarcoma. The remaining 10 patients were treated with segmental resection and reconstruction. The operation time ranged 2.5–4.5 h (average: 3.2 h). Intraoperative blood loss ranged from 300 to 500 ml (average: 368 ml). The local recurrence rate was 9.1%, and the overall survival rate was 100%. The average Musculoskeletal Tumor Society score was 27 (excellent and good for eight and three patients, respectively). ConclusionsThree-dimensional computer skeleton modeling and simulation-assisted resection and reconstruction of femoral trochanteric tumor is a new surgical technique, which might markedly improve the surgical effect, shorten the surgical time, increase the overall survival rate of patients with tumors, reduce the local recurrence rate, assist in the digitization and programming of femoral trochanteric tumor surgery, and improve surgical accuracy.

Clinical outcomes of proximal femoral reconstruction technique combined with THA in the treatment of high dislocation secondary to septic arthritis: a retrospective single-center study

PurposeThe aim of this retrospective study was to examine the clinical outcomes and complications of proximal femur reconstruction (PFR) combined with total hip arthroplasty (THA) in patients with high hip dislocation secondary to septic arthritis (SA).MethodsBetween September 2016 to September 2021, we performed a series of 15 consecutive PFR combined with THA on patients with high dislocation of the hip secondary to SA, of these,12 hips were reviewed retrospectively, with a mean follow-up of 2.5 years (range, 1.5-6 years). The mean age of the patients at the time of surgery was 52 years (range, 40–70 years).ResultsAll patients were followed up. At 1-year postoperative follow-up, the median HHS increased from 32.50 preoperatively to 79.50 postoperatively. The median VAS decreased from 7 before surgery to 2 at 1 year after surgery. The median LLD reduced from 45 mm preoperatively to 8 mm at 1 year after surgery. The mean operative time 125 ± 15 min (range 103-195 min). Mean estimated blood loss was500 ± 105ml (range 450–870 ml). Mean hospital days 9.5 days (range 6–15 days). Two patients developed nerve injuries that improved after nutritional nerve treatment. One patient had recurrent postoperative dislocation and underwent reoperation, with no recurrence dislocation during the follow-up. There were no cases of prosthesis loosening during the follow-up period. One patient developed acute postoperative periprosthetic joint infection (PJI) that was treated with Debridement, Antibiotics and Implant Retention (DAIR) plus anti-infective therapy, with no recurrence during 2 years of follow-up.ConclusionThis study indicates PFR combined with THA shows promise as a technique to manage high hip dislocation secondary to SA, improving early outcomes related to pain, function, and limb length discrepancy.

Long-lasting Limb Salvage After Malignant Femoral-Bone Tumor Resection Reconstructed With a Thin-mantle Titanium Stem Fixated With Cement.

The purpose of the present study was to review and report clinical outcomes of the Kyocera Modular Limb Salvage System (KMLS) using a thin-mantle titanium stem fixated with cement, for reconstruction after resection of malignant femoral-bone tumors. Twenty consecutive patients who had undergone reconstruction using the KMLS with cemented thin-mantle titanium stem fixation between July 2010 and December 2019 at Ryukyu University Hospital were included. We retrospectively collected the following data: age, sex, follow-up period, tumor location, histological diagnosis, stem size, overall implant survival, radiolucency, postoperative complications, overall survival, and oncological survival. The median follow-up period was 63 months (range=10.7-261 months). The bone tumors were in the proximal part of the femur in 9 patients and in the distal part of the femur in 11 patients. The 5-year overall implant survival rate was 90.9% among surviving patients. A revision surgery was required for only one patient (5%), due to infection. Radiolucency, due to an instability of the implant, was observed in 7 out of 20 patients: 6 patients with distal femoral reconstruction, and 1 patient with proximal femoral reconstruction. However, none of the patients complained of any symptoms or required revision surgeries at the last follow-up. The 5-year overall patient-survival rate was 67.6%. The KMLS with cemented thin-mantle titanium stem fixation for femoral bone reconstruction after resection for bone malignancy resulted in long-term patient benefit.

Does a novel bridging collar in endoprosthetic replacement optimise the mechanical environment for osseointegration? A finite element study.

Introduction: Limb-salvage surgery using endoprosthetic replacements (EPRs) is frequently used to reconstruct segmental bone defects, but the reconstruction longevity is still a major concern. In EPRs, the stem-collar junction is the most critical region for bone resorption. We hypothesised that an in-lay collar would be more likely to promote bone ongrowth in Proximal Femur Reconstruction (PFR), and we tested this hypothesis through validated Finite Element (FE) analyses simulating the maximum load during walking. Methods: We simulated three different femur reconstruction lengths (proximal, mid-diaphyseal, and distal). For each reconstruction length one in-lay and one traditional on-lay collar model was built and compared. All reconstructions were virtually implanted in a population-average femur. Personalised Finite Element models were built from Computed Tomography for the intact case and for all reconstruction cases, including contact interfaces where appropriate. We compared the mechanical environment in the in-lay and on-lay collar configurations, through metrics of reconstruction safety, osseointegration potential, and risk of long-term bone resorption due to stress-shielding. Results: In all models, differences with respect to intact conditions were localized at the inner bone-implant interface, being more marked in the collar-bone interface. In proximal and mid-diaphyseal reconstructions, the in-lay configuration doubled the area in contact at the bone-collar interface with respect to the on-lay configuration, showed less critical values and trends of contact micromotions, and consistently showed higher (roughly double) volume percentages of predicted bone apposition and reduced (up to one-third) percentages of predicted bone resorption. In the most distal reconstruction, results for the in-lay and on-lay configurations were generally similar and showed overall less favourable maps of the bone remodelling tendency. Discussion: In summary, the models corroborate the hypothesis that an in-lay collar, by realising a more uniform load transfer into the bone with a more physiological pattern, creates an advantageous mechanical environment at the bone-collar interface, compared to an on-lay design. Therefore, it could significantly increase the survivorship of endo-prosthetic replacements.

INTRAMEDULLARY FIXATION OF DOUBLE-BARREL VASCULARIZED FIBULA GRAFTS WITH SUBSEQUENT LENGTHENING FOR RECONSTRUCTION OF THE DISTAL FEMUR IN PATIENTS WITH OSTEOSARCOMA

IntroductionThe use of vascularised fibula grafts is an accepted method for reconstructing the distal femur following resection of malignant childhood tumours. Limitations relate to the mismatch of the cross-sectional area of the transplanted fibula graft and thel ocal bone, instability of the construct and union difficulties. We present midterm results of a unique staged technique—an immediate defect reconstruction using a double-barrel vascularised fibula graft set in in A-frame configuration and a subsequent intramedullary femoral lengthening.Materials &amp; MethodsWe retrospectively included 10 patients (mean age 10 y)with an osteosarcoma of the distal femur, who were treated ac-cording to the above-mentioned surgical technique. All patients were evaluated with regards to consolidation of the transplanted grafts, hypertrophy at the graft-host junctions, leg length discrepancies, lengthening indices, complications as well as functional outcome.ResultsThe mean defect size after tumour resection was 14.5 cm, the mean length of the harvested fibula graft 22 cm, resulting in a mean (acute) shortening of 4.7 cm (in 8 patients). Consolidation was achieved in all cases, 4 patients required supplementary bone grafting. Hypertrophy at the graft-host junctions was observed in78% of the evaluable junctions. In total 11 intramedullary lengthening procedures in 9 patients had been performed at the last follow up. The mean Muskuloskeletal Society Rating Scale(MSTS) score of the evaluable 9 patients was 85% (57% to 100%)with good or excellent results in 7 patients.ConclusionsA-frame vascularised fibula reconstructions showed encouraging results with respect to defect reconstruction, length as well as function and should therefore be considered a valuable option for reconstruction of the distal femur after osteosarcoma resection. The surgical implementation is demanding though, which is emphasized by the considerable high number of com-plications requiring surgical intervention, even though most were not serious.

Combining Shelf Osteotomy With Proximal Femoral Reconstruction After Oncologic Resection

Introduction: Oncologic proximal femoral resection and reconstruction in skeletally immature children remains a formidable task due to the risk of developing hip instability with patient growth or interval leg lengthening through the prosthesis. Shelf pelvic osteotomy increases femoral head coverage and containment, and favorable long-term results have been reported in the setting of developmental dysplasia of the hip and Perthes disease. We present a technique of combining shelf osteotomy with expandable proximal femoral endoprosthesis reconstruction in pediatric limb-sparing surgery. Materials and Methods: Four surgeons at 2 centers from 2012 to 2020 performed proximal femoral reconstruction with shelf osteotomy. Data were collected retrospectively on operative technique, radiographic measurements, and complications including dislocation, subluxation, implant loosening, pain, function, and radiographic outcomes. Results: Five patients were included in the study. The mean follow-up was 49 months (range: 17 to 104 mo). The mean lateral center edge angle status postproximal femoral resection and reconstruction shelf osteotomy was 56.1 degrees (±30.5). There were no reported incidences of subluxations, dislocations, periprosthetic fractures, or soft tissue complications. The 3 patients with the longest follow-up at 3, 5, and 8 years tolerated serial lengthening of the endoprosthesis totaling 1 cm, 7.25 cm, and 9 cm, respectively, and demonstrated earlier triradiate cartilage closure in the operative side compared with the nonoperative side. All patients have returned to independent ambulation. Discussion: Combining proximal femoral reconstruction with shelf osteotomy in limb salvage pediatric orthopedic oncology may help to improve hip stability with serial lengthening and patient growth.

Design of well-matched end-structure of anatomical proximal femoral locking plate based on computer-assisted imaging combined with 3D printing technology: a quality improvement study.

The extramedullary locking plate system was the common internal fixation method for hip fractures. However, common plates were poorly matched to femur, which was because they were designed based on anatomical parameters of the Western populations. Therefore, the aim was to design an end-structure of the anatomical proximal femoral locking plate that closely matched the anatomy of the Chinese population. From January 2010 to December 2021, consecutive patients aged 18 years and older who underwent a full-length computed tomography scan of the femur were included. The end-structure (male and female model) of the anatomical proximal femoral locking plate was designed based on anatomical parameters of femurs that were measured in three-dimensional space using computer-assisted virtual technology. The match degree between the end-structure and femur were evaluated. Inter-observer and intra-observer agreement for the evaluation of match degree was assessed. The matching evaluation based on a three-dimensional printing model was regarded as the gold standard to assess the reliability. A total of 1672 patients were included, with 701 men and 971 women. Significant differences were seen between male and female for all parameters of the proximal femur (all P <0.001). All match degree of end-structure was over 90%. Inter-observer and intra-observer agreement was almost perfect (all kappa value, >0.81). The sensitivity, specificity, and percentage of correct interpretation of matching evaluation in the computer-assisted virtual model was all greater than 95%. From femur reconstruction to completion of internal fixation matching, the process takes about 3min. Moreover, reconstruction, measurement, and matching were all completed in one system. The results showed that based on the larger sample of femoral anatomical parameters, a highly matching end-structure of anatomical proximal femoral locking plate for Chinese population could be designed with use of computer-assisted imaging technology.

Femur reconstruction in 3D ultrasound for orthopedic surgery planning.

Derotation varisation osteotomy of the proximal femur in pediatric patients usually relies on 2-dimensional X-ray imaging, as CT and MRI still are disadvantageous when applied in small children either due to a high radiation exposure or the need of anesthesia. This work presents a radiation-free non-invasive tool to 3D-reconstruct the femur surface and measure relevant angles for orthopedic diagnosis and surgery planning from 3D ultrasound scans instead. Multiple tracked ultrasound recordings are segmented, registered and reconstructed to a 3D femur model allowing for manual measurements of caput-collum-diaphyseal (CCD) and femoral anteversion (FA) angles. Novel contributions include the design of a dedicated phantom model to mimic the application ex vivo, an iterative registration scheme to overcome movements of a relative tracker only attached to the skin, and a technique to obtain the angle measurements. We obtained sub-millimetric surface reconstruction accuracy from 3D ultrasound on a custom 3D-printed phantom model. On a pre-clinical pediatric patient cohort, angular measurement errors were [Formula: see text] and eventually [Formula: see text] for CCD and FA angles, respectively, both within the clinically acceptable range. To obtain these results, multiple refinements of the acquisition protocol were necessary, ultimately reaching success rates of up to 67% for achieving sufficient surface coverage and femur reconstructions that allow for geometric measurements. Given sufficient surface coverage of the femur, clinically acceptable characterization of femoral anatomy is feasible from non-invasive 3D ultrasound. The acquisition protocol requires leg repositioning, which can be overcome using the presented algorithm. In the future, improvements of the image processing pipeline and more extensive surface reconstruction error assessments could enable more personalized orthopedic surgery planning using cutting templates.

Occlusive wound closure prevents prolonged wound discharge-A randomised controlled trial in patients undergoing tumour resection and endoprosthetic reconstruction of the proximal femur because of metastatic bone disease.

Prolonged wound discharge is a common postoperative complication of orthopaedic procedures and a risk factor for implant-related infection. Occlusive wound closure methods have previously been suggested to reduce or even prevent this complication. We performed a randomised controlled trial on 70 patients who underwent surgical treatment for metastatic bone disease involving the proximal femur at our centre between January 2017 and August 2018. At conclusion of the tumour resection and endoprosthetic reconstruction procedure, patients were randomised to either occlusive wound closure (n=35), using the Dermabond Prineo-22 skin closure system, or routine wound closure with conventional skin staples (n=35). Skin closure with occlusive wound closure resulted in a lesser degree (P < .0001) and shorter duration of postoperative wound discharge (HR 2.89 [95% CI 1.6-5.05], P < .0018). Compared with staples, surgical wounds were already dry after a mean of 3.5 days [95% CI 3.2-3.9] versus 6.1 days [95% CI 4.8-7.3] (P < .0001). Prolonged wound discharge for 7 days or more was observed in 23% of patients (n=8) in the Staples-group but was entirely absent in the occlusive wound closure group (P < .003). This study provides strong evidence that occlusive wound closure reduces frequency, degree, and duration of wound discharge in a patient population at particularly high risk for this complication.

2D-3D reconstruction of the proximal femur from DXA scans: Evaluation of the 3D-Shaper software.

Introduction: Osteoporosis is currently diagnosed based on areal bone mineral density (aBMD) computed from 2D DXA scans. However, aBMD is a limited surrogate for femoral strength since it does not account for 3D bone geometry and density distribution. QCT scans combined with finite element (FE) analysis can deliver improved femoral strength predictions. However, non-negligible radiation dose and high costs prevent a systematic usage of this technique for screening purposes. As an alternative, the 3D-Shaper software (3D-Shaper Medical, Spain) reconstructs the 3D shape and density distribution of the femur from 2D DXA scans. This approach could deliver a more accurate estimation of femoral strength than aBMD by using FE analysis on the reconstructed 3D DXA. Methods: Here we present the first independent evaluation of the software, using a dataset of 77 ex vivo femora. We extend a prior evaluation by including the density distribution differences, the spatial correlation of density values and an FE analysis. Yet, cortical thickness is left out of this evaluation, since the cortex is not resolved in our FE models. Results: We found an average surface distance of 1.16mm between 3D DXA and QCT images, which shows a good reconstruction of the bone geometry. Although BMD values obtained from 3D DXA and QCT correlated well (r 2 = 0.92), the 3D DXA BMD were systematically lower. The average BMD difference amounted to 64mg/cm3, more than one-third of the 3D DXA BMD. Furthermore, the low correlation (r 2 = 0.48) between density values of both images indicates a limited reconstruction of the 3D density distribution. FE results were in good agreement between QCT and 3D DXA images, with a high coefficient of determination (r 2 = 0.88). However, this correlation was not statistically different from a direct prediction by aBMD. Moreover, we found differences in the fracture patterns between the two image types. QCT-based FE analysis resulted mostly in femoral neck fractures and 3D DXA-based FE in subcapital or pertrochanteric fractures. Discussion: In conclusion, 3D-Shaper generates an altered BMD distribution compared to QCT but, after careful density calibration, shows an interesting potential for deriving a standardized femoral strength from a DXA scan.

Clinical and Radiographic Outcomes of a Monoblock Fluted Titanium-Tapered Stem for Paprosky IIIa, IIIb, and IV Femoral Bone Defects

BackgroundModern fluted titanium-tapered stems (FTTS) have been increasingly utilized to achieve primary stability in conversion and revision total hip arthroplasty with major femoral bone loss. This study sought to determine the radiographic and clinical outcomes of a monoblock FTTS in patients who had major femoral bone loss. MethodsA multicenter retrospective observational study of all total hip arthroplasty patients who received a monoblock FTTS who had up to 5-year radiographic follow-up was conducted. Only patients with femoral Paprosky classifications of IIIa, IIIb, and IV were included. Eighty-one monoblock FTTS were examined. Median clinical follow-up was 29 months (range, 18 to 58). Stem subsidence and loosening were assessed on most recent radiographs. All-cause revisions and stem survivals were assessed. ResultsMedian subsidence was 1.4 millimeters (mm) (range, 0 to 15.0). Sixteen (23.9%) and 3 (4.5%) stems had subsidence greater than 5 and 10 mm, respectively. All stems not acutely revised appeared stable, without evidence of loosening, at latest follow-up. Ten hips (12.3%) required reoperations. Of these, only 5 (6.2%) stems were removed; 4 due to periprosthetic joint infection and 1 for surgical exposure during acetabular revision. Kaplan–Meier analyses yielded an all-cause stem survivorship of 95.1% at 2-years and 87.1% at 4-years. Stem survivorships excluding septic causes was 98.8% at both 2 and 4 years. ConclusionMonoblock FTTS in complex femoral reconstruction cases showed encouraging clinical and radiographic results in patients who had severe femoral bone loss at median 29 months follow-up.