Single-incision Non-weight-bearing Area Autologous Osteochondral Transplantation for the Treatment of Osteochondral Lesions of the Talus

Background: Autologous osteochondral transplantation (AOT) is one of the most effective treatments for osteochondral lesions of the talus (OLTs). Normally, medial malleolar osteotomy is used to expose posteromedial lesions. However, medial malleolar osteotomy causes additional ankle injuries and a risk of persistent pain in the ankle joint. The purpose of the current study was to evaluate a new medial malleolar triplane osteotomy method and the functional outcomes of AOT from a non-weight-bearing area of the talus for OLTs.Methods: Twenty-three patients (23 ankles), including 14 males and 9 females, received AOT with triplane osteotomy of the medial malleolus for symptomatic OLTs between September 2015 and December 2017. The mean age was 35.6 years. The mean size of the lesion area was 141.5 mm2. The visual analog scale (VAS) for pain during walking and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used for the pre- and postoperative evaluations. In addition, the incorporation of the grafts was assessed by computed tomography (CT).Results: All patients had a minimum follow-up of 22 months, with an average of 37.1 months. The mean time from osteotomy to full weight-bearing activity was 8.1±2.3 weeks (range, 5-12 weeks). The VAS score improved from 4.34 preoperatively to 0.53 postoperatively (P <0.01). The AOFAS ankle-hindfoot score improved significantly in all domains (P<0 .01). Twenty-one patients returned to sport at their previous level, and 2 returned at a lower level compared with preinjury (mean return to play, 7.4 months). According to CT, the medial malleolus recovered in all patients, and the graft was incorporated well. One patient suffered from flexor hallucis longus tendon discomfort due to internal fixation screw irritation posteromedial to the ankle. The general complication rate was 4.3% (1/23).Conclusions: AOT combined with medial malleolus triplane osteotomy is a viable option for OLTs. Patients could perform weight-bearing exercise and return to sport as early as possible, with few complications at the osteotomy site and donor site.

Allograft Fibula Combined with Cannulated Screw for Femoral Head Necrosis: A Finite Element Analysis

Background: Osteonecrosis of femoral head (ONFH) is characterized by high incidence and disability. Allograft fibula combined with cannulated screw has been extensively applied for treating Osteonecrosis of femoral head. However, its biomechanical outcomes remain unclear. The present study aimed to investigate the optimal placement of the allograft fibula and cannulated screw for treating ONFH.Methods: Two types (C1 and C2) of NONFH finite element models were built based on a healthy subject and the Japanese Investigation Committee (JIC) classification system. The allograft fibula combined with cannulated screw was simulated in the respective type of the model. Different models were built by complying with the different positions of allograft fibula and cannulated screw (below model, posteriorly below model, anteriorly below model and anteriorly above model). Furthermore, a comparison was drawn on the maximum stress value and the mean stress value of the subchondral cortical bone of femoral head weight-bearing area.Results: As indicated from the finite element analysis, normal femoral head, necrotic femoral head and postoperative femoral head achieved the different maximum stress values, and the maximum stress value achieved by necrotic femoral head significantly reached over that of normal femoral head. After the operation, the maximum stress value of subchondral cortical bone in the weight-bearing area of the femoral head was noticeably down-regulated compared with that before the operation (necrotic femoral head). When the cannulated screw was directly below the fibula, subchondral cortical bone in the weight bearing area of femoral head achieved the smallest maximum stress value and average stress value, which showed a statistical difference from those of other models (P<0.05).Conclusion: Allograft fibula combined with cannulated screw is capable of significantly reducing the stress of subchondral cortical bone in the weight-bearing area of the ONFH femoral head, as well as down-regulating the stress concentration in the ONFH weight-bearing area. For JIC C1 and C2 osteonecrosis of the femoral head, when administrated with allograft fibula combined with cannulated screw, the optimal biomechanics was the cannulated screw located just directly below the fibula.

Implantation of autologous Expanded Mesenchymal Stromal Cells in Hip Osteonecrosis through Percutaneous Forage: Evaluation of the Operative Technique

Bone forage to treat early osteonecrosis of the femoral head (ONFH) has evolved as the channel to percutaneously deliver cell therapy into the femoral head. However, its efficacy is variable and the drivers towards higher efficacy are currently unknown. The aim of this study was to evaluate the forage technique and correlate it with the efficacy to heal ONFH in a multicentric, multinational clinical trial to implant autologous mesenchymal stromal cells expanded from bone marrow (BM-hMSCs). Methods: In the context of EudraCT 2012-002010-39, patients with small and medium-sized (mean volume = 13.3%, range: 5.4 to 32.2) ONFH stage II (Ficat, ARCO, Steinberg) C1 and C2 (Japanese Investigation Committee (JIC)) were treated with percutaneous forage and implantation of 140 million BM-hMSCs in a standardized manner. Postoperative hip radiographs (AP—anteroposterior and lateral), and MRI sections (coronal and transverse) were retrospectively evaluated in 22 patients to assess the femoral head drilling orientation in both planes, and its relation to the necrotic area. Results: Treatment efficacy was similar in C1 and C2 (coronal plane) and in anterior to posterior (transverse plane) osteonecrotic lesions. The drill crossed the sclerotic rim in all cases. The forage was placed slightly valgus, at 139.3 ± 8.4 grades (range, 125.5–159.3) with higher dispersion (f = 2.6; p = 0.034) than the anatomical cervicodiaphyseal angle. Bonferroni’s correlation between both angles was 0.50 (p = 0.028). More failures were seen with a varus drill positioning, aiming at the central area of the femoral head, outside the weight-bearing area (WBA) (p = 0.049). In the transverse plane, the anterior positioning of the drill did not result in better outcomes (p = 0.477). Conclusion: The forage drilling to deliver cells should be positioned within the WBA in the coronal plane, avoiding varus positioning, and central to anterior in the transverse plane. The efficacy of delivered MSCs to regenerate bone in ONFH could be influenced by the drilling direction. Standardization of this surgical technique is desirable.

Degradation of subchondral bone collagen in the weight-bearing area of femoral head is associated with osteoarthritis and osteonecrosis

Background The aim of the study was to evaluate the change of subchondral bone collagen and trabecular bone in the weight-bearing area of femoral head from patients with osteoarthritis (OA) or osteonecrosis of femoral head (ONFH), and discuss the effect of collagen degradation on OA and ONFH. Methods Femoral heads from patients with femoral neck fracture (FNF) were collected as control group. All collected samples were divided into OA group (N = 10), ONFH group (N = 10), and FNF group (N = 10). Differences of subchondral bone collagen were compared through scanning electron microscope (SEM) observation, immunohistochemistry staining, and Masson’s trichrome staining. Alteration of subchondral bone was displayed through hematoxylin and eosin (H&E) staining and gross morphology. Results SEM results showed that collagen fibers in OA and ONFH group appeared to be thinner, rougher, sparser, and more wizened. Immunohistochemistry and Masson’s trichrome staining results demonstrated that the content of collagen fibers in the OA and ONFH group was obviously less than the FNF group. H&E staining results showed that trabecular bone in OA and ONFH group appeared to be thinner and ruptured. Gross morphology results showed that the degeneration and destruction of cartilage and subchondral bone in OA and ONFH group were severer than FNF group. The characteristics mentioned above in ONFH group were more apparent than OA group. Conclusions This study revealed that degradation of collagen fibers from subchondral bone in the weight-bearing area of femoral head was associated with OA and ONFH, which may help to find new therapeutic strategies of the diseases.

Cervicothoracic Fixation by Domino Connector in Cervicothoracic Junction Tuberculosis–A Case Report

Cervicothoracic junction tuberculosis involves the C7 to D3 levels of the spine which constitutes 5% of all spinal tuberculosis. As the cervicothoracic junction is transitional zone and a weight-bearing area, the anatomical considerations for treatment of cervicothoracic junction is very difficult. We did a lateral mass screw for C5, 6, and 7 and pedicle screw of D3 and 4 levels, and connected cervical 3.5 mm rod with thoracic 5.5 mm rod using a domino connector. We gave antituberculosis therapy for 18 months. We followed-up the patient routinely and she significantly improved.

Biomechanical Analysis of Fibular Graft Techniques for Nontraumatic Osteonecrosis of Femoral Head: A Finite Element Analysis

Background: Free vascularized fibula graft (FVFG) technique has achieved the most consistent successful therapeutic effect on young patients diagnosed as nontraumatic osteonecrosis of femoral head (NONFH), of which the Core Track Technique (CTT) has been the most commonly used. As an alternative to CTT, the modified Light Bulb Technique (LBT) was reported to have a higher success rate. However, its biomechanical characters have been poorly understood. This study aimed to investigate the biomechanical properties of modified LBT in treating NONFH by comparing with CTT.Methods: Two types (C1 and C2) of NONFH finite element models were established from a healthy subject according to the Japanese Investigation Committee (JIC) classification, and CTT and LBT procedures were simulated in each type of the models. The average Von Mises stresses and stiffness of the proximal femur were calculated by applying 250% body weight loading on femoral head to simulate walking condition. In addition, two patient-specific models were built and simulated under the same boundary condition for the further validation of LBT.Results: In the healthy subject-derived models, both LBT and CTT resulted in reduced stresses in the weight-bearing area, central femoral head, femoral neck, and trochanteric and subtrochanteric regions, and increased structural stiffness after surgery. In the weight-bearing area, CTT reduced more stresses than LBT (36.19% vs 31.45%) for Type C1, while less reduction (23.63% vs 26.76%) for Type C2. In patient-specific models, stiffness and stresses of before and after surgery were also increased and reduced respectively, which is consistent with healthy subject-derived models.Conclusion: LBT and CTT have different biomechanical performance on different JIC type of NONFH. In terms of preventing the collapse of femoral head, LBT may be more effective for JIC Type C2, which could alternatively be chosen, while for JIC Type C1, CTT is still a better choice. Both techniques can improve biomechanical properties of NONFH with patients’ proximal femur stress reduced and structural stiffness enhanced.