Vascularized Femoral Myo-Periosteal Graft for Congenital Pseudarthrosis of the Tibia: A Case Report.

Pure vascularized periosteal transplants have been shown to be extremely effective at achieving rapid bone healing in children with biologically complex non-union. Free tibial and fibular periosteal transplants are generally indicated when large periosteal flaps are necessary. We report using a vascularized femoral myo-periosteal graft (VFMPG) to treat distal tibial osteotomy non-union in a six-year-old boy with congenital pseudarthrosis of the tibia. The graft consisted of a 9 cm myo-periosteal flap (after 50% of elastic retraction) that incorporated the vastus intermedius muscle and diaphyseal femoral periosteum nourished by the descending branch of the lateral circumflex femoral vessels. Plantaris medialis was used as a recipient vessel. Healing occurred 10 weeks after surgery. The patient resumed gait and sports activity without orthosis. No donor or recipient site complications occurred 17 months after surgery. Employing a VFMPG might be an alternative to other free or large vascularized periosteal flaps currently in use for complex pediatric non-unions.

Morbidity Associated With Distal Tibial Autograft Harvest.

Distal tibial autograft harvesting has been studied in the past, but morbidity at the level of the donor site is unclear. The purpose of this retrospective review is to assess morbidity in distal tibial autograft harvesting associated with foot and ankle arthrodesis procedures. A retrospective analysis was performed utilizing patients treated in the last 13 years at a large, multicenter, academic, tertiary referral, research institution. Included patients were between the ages of 18 and 80 years old. One-hundred and seven patients (39 male; 68 female) underwent ipsilateral distal tibial bone graft (n = 110) harvesting to augment the index procedure. Patients were followed for an average of 11.2 months after surgery (Range: 1-73 months). The incidence rate of distal tibial stress fractures was 4.5%, with an overall postoperative complication rate of 8.2%. Overall, low complication rates associated with distal tibial autograft harvesting were found, supporting the use of the distal tibia as an appropriate site for autograft harvesting in foot and ankle surgery.

Editorial Commentary: Autologous and Synthetic Bone Fillers for Medial Open-Wedge High Tibial Osteotomy Have No Effect on Clinical Outcomes But Autologous Graft Promotes Complete Bony Union.

In contrast to closed-wedge high tibial osteotomy, medial based open-wedge high tibial osteotomy produces gaps of various sizes. Synthetic bone void fillers are an attractive option to close these gaps, potentially increase bone union, decrease time to union, and improve clinical outcomes. Autologous bone grafts are the accepted standard and result in reliable and reproducible outcomes. However, harvesting of autologous bone requires an additional procedure and is associated with potential complications. The use of synthetic bone void fillers could theoretically avoid these issues and reduce operating times. The current evidence suggests that autologous bone grafting has higher union rates but is not associated with better clinical and functional outcomes. Unfortunately, the certainty of evidence to support the use of bone void fillers is low, and the question of whether bone grafting of the gap should be performed in medial based open-wedge high tibial osteotomies cannot be answered with confidence.

Editorial Commentary: It is Never Wrong to Perform Anterior Cruciate Ligament Revision Reconstruction as a Two-Stage Procedure.

Revision anterior cruciate ligament (ACL) reconstruction can be performed in a single surgery, but in some instances, it requires 2 stages to get it right. The most common reasons for staged reconstruction include dilated bone tunnels on the tibial or femoral side (>13 mm), imperfectly placed bone tunnels that cannot be reused but cannot be avoided, and/or the need to combine the revision ACL reconstruction with meniscus and/or cartilage allograft transplantation. In my practice, we use prefabricated bone dowels, sizing up 0.5 to 1 mm relative to the size of the tunnel (after debridement) for both the femoral side and tibial side. The benefits are efficiency and reproducibility, while the challenges include cost and the potential need for multiple dowels if the prefabricated dowels are not long enough. We will occasionally add demineralized bone matrix, particularly on the tibial side, in the event that there is <5 mm of unfilled tunnel using the bone dowel. We wait ∼3 months before proceeding to the second stage using only plain radiographs to assess healing (advanced imaging such as computed tomography scan is not routinely used). We have also begun to push the limits of single-stage revision reconstruction, using dowels in a single setting. No matter what, it is never wrong to perform ACL revision reconstruction as a 2-stage procedure. When performed for the appropriate indications, outcomes tend to be good, regardless of the chosen technique.

Complications associated using the reamer-irrigator -aspirator (RIA) system: a systematic review and meta-analysis.

INTRODUCTION: Complications associated with the application of the Reamer-irrigator-Aspirator (RIA) system are described in the literature. However, to date a systematic review and meta-analysis to assess prevalence of complications associated with the use of the RIA system have not been conducted. MATERIALS AND METHODS: The review is registered with PROSPERO (CRD42021269982). MEDLINE, the Web of Science Core Collection, and Embase were searched from the inception to 10 August 2021. The primary objective was to assess complications and blood loss associated with the use of the RIA system. RESULTS: Forty-seven studies involving 1834 procedures performed with the RIA system were finally included. A total of 105 complications were reported, with a pooled estimated overall prevalence of 1.7% with a 95% confidence interval (CI) of 0.40 to 3.60, with cortex perforation being the largest reported complication with a total of 34 incidences. A significant subgroup difference was observed (p = 0.02). In subgroup 1 (bone graft harvesting), complication prevalence was 1.4% (95% CI 0.2-3.4); in subgroup 2 (clearance intramedullary canal) it was 0.7% (95% CI 0.00-6.30) and in subgroup 3 (reaming with RIA system prior to nail fixation) 11.9% (95% CI 1.80-26.40). No statistically significant difference for tibia and femur as RIA system application site was observed (CI 0.69-4.19). In studies reporting blood loss, a mean volume of 803.29 ml, a mean drop of hemoglobin of 3.74 g/dl and a necessity of blood transfusion in 9.72% of the patients were observed. CONCLUSIONS: The systematic review and meta-analysis demonstrate a low overall prevalence rate of complications associated with the RIA system. However, especially the risk of cortical perforation and the frequently reported relevant intraoperative blood loss are complications that should be anticipated in perioperative management and ultimately considered when using the RIA system.

Donor site morbidity of calcaneal, distal tibial, and proximal tibial cancellous bone autografts in foot and ankle surgery. A systematic review and meta-analysis of 2296 bone grafts.

PURPOSE: This study aims to report on the safety and donor site morbidity of the distal lower extremity (calcaneal, proximal, and distal tibial) cancellous bone autografts. We summarized the findings in a comprehensive infographic illustration. We are unaware of any similar meta-analyses to date. METHODS: Following the PRISMA guidelines, two independent investigators searched MEDLINE (PubMed), EMBASE, SCOPUS, Google Scholar, and Cochrane databases in December 2020 using the following keywords and their synonyms: ("bone graft", "donor site morbidity", "calcaneal graft", "proximal tibia graft", and "distal tibia graft"). Besides, the reference lists from previous review articles were searched manually for eligible studies. The primary outcomes of interest were (1) chronic pain, (2) fracture, and (3) infection, whereas the secondary outcomes were (1) neurological complications, (2) sensory disturbance and hypertrophic scars, (3) other complications such as shoe-wear difficulties and gait disturbance. Inclusion criteria were: studies on complications and adverse events of lower extremity bone autografts (calcaneal, proximal tibial, and distal tibial bone autografts) reporting at least one of the desired outcomes. Studies not reporting any of the outcomes of interest or if the full text is not available in English were excluded. Studies reporting on bone marrow aspirate or autografts for non-orthopedic indications were also excluded. RESULTS: After the removal of duplicates, a total of 5981 studies were identified. After screening those records, 85 studies remained for full-text assessment. Out of those, 15 studies qualified for the meta-analysis with a total of 2296 bone grafts. Out of those grafts, 1557(67.8%) were calcaneal grafts, 625 (27.2%) were proximal tibial grafts, and 114 (5%) were distal tibial grafts. In calcaneal bone grafts, there were 28 cases of chronic pain [1.97%, CI:1.10-2.50%, I2 = 66%], 5 fractures [0.32%, CI: 0.10-0.60%,I2 = 0%], 20 sural neuritis [1.28%, CI:0.70-1.80%, I2 = 0%), and no wound infections. In proximal tibial grafts there were 13 cases of chronic pain [2.08%, CI: 1.01-3.2%, I2 = 34.5%], 1 fracture [0.16%, CI:0.10-0.50%, I2 = 0%], and 3 superficial wound infections [0.48%, CI: 0.10-1.01, I2 = 0%]. In the distal tibial grafts there were no cases of chronic pain or wound infections, 1 fracture [0.90%, CI: 0.80-2.6%, I2 = 0%], and 5 saphenous neuritis [4.5%, CI: 0.70-8.40%, I2 = 65%]. CONCLUSION: Calcaneal, distal tibial, and proximal tibial bone autografts are safe with a low rate of overall and major complications. We report an overall complication rate of 6.8%, which is less than half of that previously reported for iliac crest grafts. The authors recommend using distal lower extremity grafts for foot and ankle primary surgeries instead of iliac crest grafts when indicated. Clinical trials with a large sample size are required.

Do Massive Allograft Reconstructions for Tumors of the Femur and Tibia Survive 10 or More Years after Implantation?

BACKGROUND: Massive bone allografts have been used for limb salvage in patients undergoing bone tumor resections as an alternative to endoprostheses. Although several studies on massive allograft reconstructions for bone tumors reported that most complications occur in the first 3 years after surgery, there are no long-term reports on complications to substantiate this contention. We believe such information is important so that surgeons and patients can make more informed decisions when choosing a reconstructive method after tumor resection. QUESTIONS/PURPOSES: (1) What is the survival of allografts free from removal, amputation, or joint replacement in patients treated for bone tumors in the lower limb with a minimum of 10 years of followup? (2) What complications occur after 10 or more years of followup? (3) Are there factors associated with allograft survival, such as age, sex, the affected bone, reconstruction type (intercalary or osteoarticular allograft), tumor type (malignant or benign), failure type, and chemotherapy use? METHODS: We retrospectively analyzed the records of 398 patients treated in one center with benign or malignant bone tumors in the femur or tibia between 1986 and 2007. During the period in question, our general indications for using allografts (354 patients) included patients with benign or low-grade sarcomas and patients with high-grade sarcomas with clinical and imaging response to neoadjuvant chemotherapy. Other approaches such as endoprostheses (44 patients) were indicated if the patient received radiotherapy, in patients with high-grade sarcomas without clinical and imaging response to neoadjuvant chemotherapy, or with neurovascular tumor involvement. We excluded from the analysis 53 patients treated with allograft-prosthetic composites, 46 with hemicondylar osteoarticular allografts, and 57 with intercalary hemicylindrical allografts. The study was thus performed in 198 patients treated with segmental massive allografts in the long bones of the lower extremity (132 femurs and 66 tibias) after resection of a primary bone tumor, including 120 patients treated with osteoarticular and 78 with segmental intercalary allografts. A total of 32 (16%) of the 198 patients died before 10 years, and graft status was known in all of those patients; these patients were included (mean followup, 192 months; range, 1-370 months). All remaining 166 patients who were not known to have died before 10 years were accounted for at least 10 years after the allograft procedure (mean, 222 months; range, 120-370 months). No patient was lost to followup. The mean age was 22 years (range, 2-55 years); 105 patients were male (53%) and 93 were female. The predominant diagnoses were osteosarcoma (n = 125, 63%), giant cell tumor of bone (n = 27, 14%), and Ewing's sarcoma (n = 19, 10%). In all, 146 patients (74%) underwent chemotherapy. Selected variables were analyzed using multivariate logistic regression analyses to identify risk factors of allograft removal, joint replacement, or amputation. We performed competitive risk analysis with allograft removal, joint replacement, or amputation as the endpoint at 5, 10, and 20 years. Patient function was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 scoring system. RESULTS: The risk of allograft removal, joint replacement, or amputation was 36% at 5 years (95% CI, 30-43), 40% at 10 years (95% CI, 33-47), and 44% at 20 years (95% CI, 37-51). Fractures occurred in 15% (29 patients), infection in 14% (27 patients), nonunion in 12% (23 patients) and tumor recurrence in 7% (13 patients). Thirty-two patients died of disease before 10 years; nine of these patients had a second surgery before death, eight had an amputation, and one underwent graft removal. Of the 166 patients who were still alive 10 years after the allograft procedure, 36 underwent allograft removal, six patients underwent joint replacement, and four had an amputation; however, after 10 years, six more allografts were removed (four due to fractures, one due to infection, and one due to instability), and another patient was amputated due to a second malignancy. After controlling for potentially confounding variables including death, we found that the risk of allograft removal, joint replacement, or amputation in osteoarticular tibial grafts (58% [95% CI, 43-73] at 5, 10, and 20 years) was higher than that of osteoarticular femur allografts (29% [95% CI, 18-39] at 5 years, 30% [95% CI, 19-40] at 10 years, 37% [95% CI, 25-48] at 20 years; p = 0.010) and tibia intercalary allografts (26% [95% CI, 7-45] at 5, 10 and 20 years; p = 0.020). Fractures occurred more frequently in the femur (18% [95% CI, 11-25]) than in the tibia (5% [95% CI, 0-10]; p < 0.010), and infections occurred more frequently in the tibia (24% [95% CI, 14-35]) than in the femur (4% [95% CI, 0-8]; p < 0.001). With the number of patients we had, we found no difference in the proportion of local recurrence in the tibia (12% [95% CI, 4-20]) compared with the femur (5% [95% CI, 1-9]; p < 0.053). CONCLUSIONS: Infections were the most common complications associated with allograft removal in the first 2 to 3 years after reconstruction and were more frequently associated with tibial allograft removal. Fractures were more commonly associated with graft removal with longer term followup and were more frequently associated with femoral allograft removal. Although we cannot directly compare our results with other types of reconstructions, we believe that allografts still have a role in the reconstruction of patients with a benign or low-grade bone tumor. Future studies in femoral allograft with longer followup should be performed to analyze factors that may explain why some grafts fail, such as the percent of the length of the bone resected, type and number of plates and screws used and type of fixation (rods versus plates). There was a higher incidence of graft removal in patients with proximal tibia osteoarticular allografts, which has led us to use this type of reconstruction only in pediatric patients over the last 15 years. LEVEL OF EVIDENCE: Level III, therapeutic study.

Inside-Out Repair of the Meniscus in Concomitant Anterior Cruciate Ligament Reconstruction: Absorbable Versus Nonabsorbable Sutures.

PURPOSE: To compare the clinical and magnetic resonance imaging (MRI) outcomes of meniscal repair using absorbable versus nonabsorbable sutures in patients undergoing concomitant anterior cruciate ligament reconstruction. METHODS: Data of 142 patients who underwent meniscal repair with concomitant anterior cruciate ligament reconstruction using either absorbable or nonabsorbable sutures for longitudinal meniscal tear were retrospectively reviewed. Inside-out suture technique was used for all meniscal repairs. Weight bearing and flexion (>90°) were allowed after 6 weeks postoperatively. Clinical evaluations were assessed by the International Knee Documentation Committee subjective score, Lysholm score, and Tegner activity score preoperatively and at 2-year follow-up. MRI outcomes at 1-year follow-up were compared to identify the successful healing (complete or partial healing) rate and incidence of additional meniscal tears. Subgroup analysis was performed to evaluate the results of medial or lateral meniscus. RESULTS: Eighty patients underwent meniscal repair using absorbable sutures (mean age, 26.3 ± 11.9 years) and 62 patients with nonabsorbable sutures (mean age, 27.2 ± 10.0 years). There were no differences in zone and length of meniscal tears and stability tests between the groups. At a 2-year follow-up, all clinical scores had improved in both groups but did not differ significantly between the groups. Successful healing rate based on 1-year postoperative MRI was not significantly different between the absorbable and nonabsorbable sutures (93.7% vs 96.8%, P = .469). However, the absorbable sutures showed a lower additional tear incidence than the nonabsorbable sutures (2.5% vs 9.6%, P = .031). Subgroup analysis showed that the successful healing rate was not significantly different between the suture materials in both the medial and lateral menisci. CONCLUSIONS: The use of absorbable sutures leads to comparable healing rates to and lower incidence of additional tears than nonabsorbable sutures in patients undergoing meniscal repair with anterior cruciate ligament reconstruction. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

Donor-Specific Human Leukocyte Antigen Antibody Formation After Distal Tibia Allograft and Subsequent Graft Resorption.

The association between donor-specific human leukocyte antigen (HLA) antibody formation and small bone allograft resorption has not been studied. We present the case of a patient treated for glenoid bone loss using a distal tibial allograft with Bankart repair who formed donor-specific HLA antibodies against the allograft and had subsequent graft resorption. X-ray and computed tomography (CT) scans were performed before and after surgery at standard checkpoints. Patient blood and serum samples were collected before and after surgery for HLA typing and HLA antibody testing. Human leukocyte antigen antibodies against the donor-specific HLA-A2 antigens were identified 6 weeks after surgery and were still detected at 5 months after surgery. At 6 months after surgery, a CT arthrogram revealed significant graft resorption. This case shows a temporal correlation between HLA antibody formation and clinical findings, potentially suggesting an association between HLA antibody formation and graft resorption. Further study is required to confirm this.

USE OF MEDIAL FEMORAL CONDYLE FLAP AND ANTEROLATERAL THIGH FREE FLAP IN PROXIMAL TIBIAL POSTTRAUMATIC NON-UNION WITH MULTIPLE ANASTOMOSIS - CASE REPORT.

Fractures of the proximal tibia are high energy fractures. According to available literature, 3-4% of all fractures heal problematically with non-union or osteomyelitis. Usage of locking compression plating system as well as usage of hybrid fixator is associated with the risk of compartment syndrome, local infection and subsequent malunion, osteomyelitis or non-union. We present a case of 30-year-old male suffering from posttraumatic non-union. The medial femoral condyle flap was selected due to its favourable properties providing a highly vascularised osteogenic tissue in combination with anterolateral thigh flap and Corlett loop. Our case report describes a reconstruction of a long weight-bearing bone. Despite the amount of anastomoses and usage of vein graft, the selected method of reconstruction seems to be safe and with a long-lasting benefit for the patient.

Comparison Matrix-Associated Stem Cell Transplantation (MAST) with Autologous Matrix Induced Chondrogenesis plus Peripheral Blood Concentrate (AMIC+PBC) in chondral lesions at the ankle-A clinical matched-patient analysis.

BACKGROUND: The aim of the study was to compare Matrix-Associated Stem Cell Transplantation (MAST) with Autologous Matrix Induced Chondrogenesis plus Peripheral Blood Concentrate (AMIC+PBC) in chondral lesions at the ankle. METHODS: In a matched-patient clinical follow-up study, patients with chondral lesion at the ankle that were treated with MAST from April 1, 2009 to July 15, 2016, and patients that were treated with AMIC+PBC from July 17, 2016 to May 31, 2017 were included and compared. Size and location of the chondral lesions and the Visual-Analogue-Scale Foot and Ankle (VAS FA) before treatment and at follow-up were analysed. Bone Marrow Aspirate Concentrate (BMAC) was used for MAST and Peripheral Blood Concentrate (PBC) for AMIC+PBC to impregnate a collagen I/III matrix (Chondro-Gide, Wollhusen, Switzerland) that was fixed into the chondral lesion with fibrin glue. RESULTS: One hundred and twenty-nine patients with 136 chondral lesions were included in both groups. The chondral lesions were located as follows (MAST/AMIC+PBC, n (%)), medial talar shoulder only, 59 (43)/62 (46); lateral talar shoulder only, 44 (32)/42 (31); medial and lateral talar shoulder, 7 (10)/7 (10); tibia, 19 (14)/18 (13). The lesion size was 1.6/1.8cm2 on average and VAS FA was 46.9/45.7 (MAST/AMIC+PBC). For MAST/AMIC+PBC groups, 107 (83%)/105 (81%) with 112/110 previous chondral lesions completed the defined 2-year-follow-up after 24.4/23.8 months on average. VAS FA improved to 82.3/79.8 (MAST/AMIC+PBC). No parameter significantly differed between MAST and AMIC+PBC groups. CONCLUSIONS: MAST and AMIC+PBC as part of a complex surgical approach led to improved and high validated outcome scores in 2-year-follow-up. MAST and AMIC+PBC showed similar results.

Fibula-pro-tibia transfer with external fixator after tibia fracture with extensive bone defect: a case report.

A 27-year-old girl suffered a tibial fracture with an extensive bone defect due to a major trauma. At first, she was treated with a plate with the purpose to obtain a fibula-pro-tibia transfer, without any improvement. At one-year-follow up, a non-union due to mechanical hardware failure was shown by x-ray. Thus, a second surgery was performed: the ipsilateral fibula was tightly wedged between the preserved proximal and distal third of tibia with an external fixator. We report a follow up of 1 year after the reconstruction that allowed a good bone healing and a remodeling with also further ossification of the periosteal sheath of the fibula.

Fifteen-Year Minimum Follow-Up of Anteromedial Tibial Tubercle Transfer for Lateral and/or Distal Patellofemoral Arthrosis.

PURPOSE: To evaluate a minimum 15-year clinical and radiographic follow-up after anteromedial tibial tubercle transfer (anteromedialization [AMZ]) for lateral and/or distal patellar facet arthrosis. METHODS: Patients treated from 1996 to 2000 were contacted. The inclusion criteria were a minimum of 15 years' follow-up after AMZ for isolated persistent retropatellar pain related to lateral and/or distal patellar chondrosis. The exclusion criteria were clinical patellar instability, revision, and significant medial patellar facet or adjacent compartment chondrosis. The anatomic location(s) and severity of arthrosis, as well as the degree of lateral maltracking, were documented. Follow-up data included pain, activity level, and satisfaction. RESULTS: Of 23 patients, 15 met the inclusion criteria. All were women (17 knees) followed up for a mean of 17.1 years (range, 15.4-18.8 years). The mean age at surgery was 29.5 years. Satisfactory results were reported in 94% of knees (16 of 17), based simply on patients' subjective evaluation of the degree of success perceived. An important criterion of satisfaction was that these patients stated they would opt to undergo surgery again under the same circumstances. For 35% of knees, patients reported engaging in recreational activities, whereas for 18%, patients were minimally active. The average pain score (range, 0-10) for 75% was 2.1, and most of these patients showed grade I or II arthrosis. Post-AMZ symptomatic medial patellar subluxation was corrected successfully in 2 patients. Removal of hardware was performed in 59% of knees, and additional procedures were required in 41%. No cases of postoperative lateral patellar instability or conversion to knee arthroplasty occurred. CONCLUSIONS: Anteromedial tibial tubercle transfer without articular cartilage implantation is effective in patellofemoral joint preservation, ameliorating symptoms and facilitating active lifestyles for a minimum of 15 years to nearly 20 years in patients with lateral and/or distal patellofemoral arthrosis. For 94% of knees, patients would choose to undergo the procedure again under the same circumstances. Fifty-nine percent underwent screw removal, and 41% required additional procedures, mostly arthroscopic. No patients in this therapeutic case series underwent an arthroplasty procedure. LEVEL OF EVIDENCE: Level IV, therapeutic cases series.

Medial patellofemoral ligament reconstruction with or without tibial tubercle transfer is an effective treatment for patellofemoral instability.

PURPOSE: The hypotheses were that medial patellofemoral ligament reconstruction (MPFLr) would improve the long-term symptoms of patellofemoral Instability (PFI) and control patellar tilt, based on computed tomography (CT), and that the addition of a TT transfer, when it is necessary, would not deteriorate the outcome. The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of a large series of MPFLr, either isolated or associated with a TT transfer. METHODS: From 133 MPFLr with a minimum of 4 years postoperatively, three groups were defined: isolated MPFLr, MPFLr with tibial tubercle (TT) medialisation or MPFLr with TT medialisation and distalisation. IKDC and Kujala scores were evaluated. Patellar tilt was evaluated on the patient's preoperative and the last available radiograph, and on CT scan measurements performed preoperatively and at 6-month postoperatively. RESULTS: The mean follow-up was 6.3 ± 1.7 years [4.1-10.3] and four patients reported recurrent patellar dislocation. Between pre and postoperative at last follow-up a significant improvement in IKDC and Kujala functional scores was observed (P < 0.01), with no difference between the three groups. Regarding patellar tilt, there were significant decreases in Laurin and Merchant angles and an improvement of the Maldague stage (P < 0.01). The CT analysis of patellar tilt also demonstrates a significant improvement of the patella tilt (P < 0.01). The control of the patella tilt was correlated with a good functional result (P < 0.01). CONCLUSION: The MPFLr, whether isolated or associated with a TT transfer, provides good long-term clinical and radiological outcomes with a low rate of recurrence. The addition of a TT transfer, when necessary, results in the same good outcomes. This article provides a guide for surgeons evaluating PFI to choose the most appropriate procedure. LEVEL OF EVIDENCE: IV.

A novel method using bone peg fixation for acute osteochondral fracture of the talus: a surgical technique.

INTRODUCTION: The osteochondral fracture of the talus is an uncommon condition, therefore, there are controversies for the optimal treatment. We report a novel surgical technique of bone peg fixation for osteochondral fracture of the talus. MATERIALS AND METHODS: We report two cases that underwent bone peg fixation for the acute osteochondral fractures of talus. Clinical and radiographic evaluations were performed at the last follow-up. RESULTS: At the last follow-up, mean ROM of ankle joint was 50° (range 45°-55°). Additionally, mean VAS and AOFAS score were 0 and 100 at the last follow-up, respectively. All patients obtained bone union without complication at the last follow-up radiographs. CONCLUSIONS: This case study shows good clinical and radiographic results with autologous bone peg fixation in patients with acute osteochondral fractures of the talus. LEVEL OF EVIDENCE: V, expert opinion.

Tibiotalocalcaneal arthrodesis with distal tibial allograft for massive bone deficits in the ankle.

BACKGROUND: The purpose of this study was to assess the outcomes of distal tibial structural allograft to obtain a stable TTC fusion. METHODS: Retrospectively, ten patients were carried out with a minimum one year follow-up. The median age was 72 (33-81). The median BMI was 28 (24-33). Indications for TTC arthrodesis included failed total ankle arthroplasty (n=7 patients), prior nonunion (n=2 patients), and a trauma injury. RESULTS: Union rate was 80%. The median initial height of the distal tibial allograft was 19mm (14-24mm). In seven cases the allograft did not lose height. The AOFAS score median was 69 (31-84). SF-12 median physical component was 39 (30-53), and 59 (23-62) for mental component. The VAS median was 2 (0-8). CONCLUSIONS: TTC using distal tibial allograft shows a lower rate of collapse than other structural grafts and provides a fusion rate higher or in accordance with the literature. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Comparison of Modified Transtibial and Outside-In Techniques in Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To compare the bending angle of anterior cruciate ligament (ACL) graft at femoral tunnel, graft maturation, and tunnel positions and the clinical outcomes of the modified transtibial (mTT) and outside-in (OI) techniques. METHODS: Patients who met the inclusion criteria were divided into the mTT group (n = 50) and the OI group (n = 50). Using 3-dimensional computed tomography (3-D CT), tunnel placement and femoral tunnel bending angle were analyzed. The 3.0-T magnetic resonance imaging (MRI) was used to assess the graft signal intensity (indicative of maturation) with signal/noise quotient (SNQ). Graft tension and synovialization were evaluated with second-look arthroscopy in all cases. Clinical and functional tests were completed at 36 months of follow-up. RESULTS: When tunnel placements were analyzed using the quadrant method, no significant differences were found between the mTT group and the OI group. The femoral graft bending angle was reduced in the mTT group, and the total mean of SNQ values and mean SNQ values at the femoral intraosseous and proximal graft of the mTT group were significantly lower than in the OI group (P < .001), respectively. The femoral graft bending angle on the coronal and axial planes showed moderate-to-strong correlation with the SNQ values at the femoral intraosseous and proximal graft. Second-look arthroscopy revealed better synovialization in the mTT group than in the OI group (P = .040), with no significant difference in graft tension between the 2 groups (P = .328). CONCLUSIONS: Anatomic tunnel placements did not vary between the mTT group and the OI group. However, the mTT group had more benefits in femoral graft bending angle and showed higher graft maturity and better synovial coverage than the OI group, although there were no significant differences in clinical outcomes. The acute femoral graft bending angle might negatively affect the maturation of proximal graft. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Anatomic and non-anatomic anterior cruciate ligament posterolateral bundle augmentation affects graft function.

PURPOSE: The purpose of this study is to compare knee laxity and graft function (tissue force) between anatomic and non-anatomic posterolateral (PL) bundle augmentation. METHODS: Twelve (n = 12) fresh-frozen mature, unpaired porcine knees were tested using a robotic testing system. Four knee states were compared: (a) intact anterior cruciate ligament (ACL), (b) deficient PL and intermediate bundles, (c) anatomic PL augmentation, and (d) non-anatomic PL augmentation. Anterior tibial translation (ATT), internal rotation (IR) and external rotation (ER), and the in situ tissue force were measured under an 89.0-N anterior tibial load and 4.0-N m internal and external tibial torques. RESULTS: Both anatomic and non-anatomic PL augmentation restored the ER, IR, and ATT of the intact knee at all knee flexion angles (n.s.). Both anatomic and non-anatomic PL augmentation restored the in situ tissue force of the ACL during ER and IR loading and ATT loading at all knee flexion angles except at 60° of knee flexion, where the non-anatomic PL augmentation did not restore the in situ tissue force of the ACL during external rotation loading and the anatomic PL augmentation did not restore the in situ tissue force of the ACL during IR loading. Furthermore, there were no differences in ATT, IR, ER, and in situ tissue force under anterior tibial loading, IR and ER loading between the two reconstruction groups. CONCLUSION: There were no significant differences between anatomic and non-anatomic PL augmentation using the porcine knee model.

A new porcine vascularized tibial bone allotransplantation model. Anatomy and surgical technique.

INTRODUCTION: Vascularized bone allotransplantation may provide new options for reconstruction of segmental defects if problems of long-term immune modulation can be solved. The current literature lacks an orthotopic large animal model, limited to bone and without the confounding effects of other tissue types, permitting a multifaceted evaluation before new methods are used clinically. The purpose of this study was to develop a large animal model for vascularized bone allotransplantation. MATERIALS AND METHODS: Eight porcine hind limbs were dissected. Length, diameter, and location of all hindlimb vessels were measured and a single nutrient vessel supplying the tibial diaphysis identified enabling its use as a vascularized bone allotransplant. Four Yucatan minipigs were divided into two pairs with a major swine leukocyte antigen mismatch. A 3.5 cm tibial segment including its nutrient pedicle was raised simultaneously from each pig and transplanted into the matched defect of the other animal. Microarterial anastomosis of the pedicle and 3-drug immunosuppression maintained VCA viability. Bone healing and limb function were followed for 16 weeks. RESULTS: A consistent tibia diaphyseal nutrient artery arose from the caudal tibial artery to enter bone a mean 2.8 mm distal to the tibial tubercle with a pedicle length of 6.6 ± 3.3 mm and diameter of 1.6 ± 0.2 mm. Using this pedicle, we reconstructed a 3.5 cm tibial defect with a vascularized bone allotransplant in four animals. Immediate weightbearing as well as progressive bone healing was demonstrated. CONCLUSION: We have developed a vascularized tibial bone allotranplantation large-animal model suitable for future bone-only allotranplantation research in mini-pigs.

Surface Properties and MC3T3-E1 Cell Response of Cortical Bone Allografts Modified with Low-Concentration Phosphoric Acid.

BACKGROUND/AIMS: This experimental study aimed to evaluate the effect of low-concentration phosphoric acid on the surface structure of cortical allografts. METHODS: Allogenic cortical bones were obtained from femurs and tibias of New Zealand white rabbits. The bones were modified by treatment with various concentrations of phosphoric acid (10%, 20% or 30%) for 10, 30 or 60 minutes, then evaluated by the following methods: 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and LIVE/DEAD assay, alkaline phosphatase (ALP) assay, biomechanical properties testing, contact angle detection, quantitative real-time polymerase chain reaction (Q-PCR), western blotting and scanning electron microscopy (SEM). RESULTS: Compared with the other groups, the group modified with 10% H3PO4 for 10 minutes had lower cytotoxicity according to MTT and LIVE/DEAD assays, higher hydrophilicity in the contact angle detection test and greater stability in the biomechanical properties test. Moreover, an up-regulation of osteopontin (OPN) in bones modified with 10% H3PO4 was observed by Q-PCR and western blotting. In addition, ALP assay and SEM showed that surface porosity and osteoinductivity were increased in the group modified with 10% H3PO4. CONCLUSIONS: Low-concentration phosphoric acid may be a potential method for surface modification of cortical allografts. Further animal experiments and animal infection model studies are required to validate the efficacy of surface-modified cortical allografts to repair large segmental bone defects.