Structural Bone Graft Research Articles

Editorial on “Bone remodeling in acetabular reconstruction using a Kerboull-Type reinforcement device and structural bone-grafting in total hip arthroplasty”

The article entitled “ Bone Remodeling in Acetabular Reconstruction Using a Kerboull-Type Reinforcement Device and Structural Bone-Grafting in Total Hip Arthroplasty” (1) was reviewed in detail. In primary or revision total hip arthroplasty, acetabular bone loss is one of the challenging conditions to place the acetabular component at the original acetabular region. Although recent advance of ultra-porous coated metal acetabular shell or augment implants may influence the surgeons’ decision making at the time of pre-operative planning for such technically demanding conditions, we have to recognize that the most important concept of total hip arthroplasty is to place the hip rotation center at around the anatomical position with preserving the bone stock of the hip joint.

Cementless acetabular component with or without upward placement in dysplasia hip: Early results from a prospective, randomised study

BackgroundTotal hip arthroplasty (THA) in developmental dysplasia of hip (DDH) is difficult for the abnormal acetabulum. The purpose of this study was to evaluate the difference of anatomic and upward placement of acetabular component during early stage. MethodsFrom April 2014 through June 2015, forty DDH patients (Crowe I to III, 42 hips) were prospectively randomized to either anatomic or upward group. Patient recorded diaries were collected. Radiographs were reviewed. WOMAC and Harris scores were tabulated from pre-operation to 12 months after surgery. ResultsThe patients' characteristics including age and body mass index (BMI) had no significant difference (P>0.05). There were no statistically differences between two groups for surgery time, intraoperative blood loss, hemoglobin (Hb), blood transfusion, albumin decrease, length of stay-day, but surgery time and blood loss in patients with structural bone graft was much higher in anatomic group. The postoperative limb-length discrepancy (LLD) was also no difference, but limb lengthening was better in anatomic group (P=0.042). The total hospital costs in the anatomic group were higher, but no significant differences. With regard to Harris and WOMAC score, there were significant improved after surgery in both groups, and the anatomic group was better in the value, but these differences were no statistically significant. ConclusionsAcetabular reconstruction for DDH subluxation should be reconstructed as close to the actual acetabular location as possible, but an appropriate (<20mm) upward placement that can achieve at least 70% native bone coverage of the acetabular implant is a valuable technique for early faster recovery.

Autologous structural iliac bone grafts in reconstructions of short bone defects in the hand and foot after primary bone tumor resections: a single-institution retrospective study.

The use of structural autografts from the iliac crest for reconstruction of bony defects in the hand and foot was described by Wilson and Lance in 1965. However, very few series of this technique are published and long-term results are unknown. We present a single-institution series of 23 patients with a mean follow-up of 92months. We also describe a novel modification of this technique using the anterior superior iliac spine for reconstruction of the adjacent joint. Failure rate was 13% at mean of 17.3months. All patients had a firm grip in the hand and walked without support. Bony fusion was achieved in all cases regardless of the type of fixation used. The use of ASIS for joint reconstruction was successful, particularly in low-demand joints. We encountered 1 case of instability and progressive stiffness in weight-bearing joints. This is a reliable method of reconstructing bony defects in the hand or foot following tumor resections.

Utilization of ring-shaped bone allograft for surgical treatment of adolescent post-tubercular kyphosis: A retrospective study.

This study aimed to investigate the mid-term outcome of ring-shaped bone allografts in the surgical treatment of adolescent post-tubercular kyphosis secondary to spinal tuberculosis.The records of adolescent patients diagnosed with spinal tuberculosis who received treatment in our department between 2009 and 2013 were retrospectively reviewed. The anterior approach was used in cases of cervical kyphosis and the posterior approach was used in cases of thoracic and lumbar kyphosis. During the surgery, the ring-shaped bone was used as a structural bone graft associated with the cancellous bone filing in the center portion of the ring shape. Cobb's angle, signs of spinal infusion on computed tomography, and complications were followed up.A total of 25 patients were included in our study. Among them, 3 involved the cervical region, 5 involved the thoracic region, 8 involved the thoracolumbar region, and 9 involved the lumbar region. The preoperative kyphosis deformity was a mean 65° Cobb's angle (40°–97°) compared to the postoperative 14° Cobb's angle (10°–21°) for an average correction of 51°. All wounds healed well without graft rejection. All patients achieved bone fusion 3 months postoperative for a 100% fusion rate.Our results show that the ring-shaped allograft bone is an effective option for the treatment of adolescent kyphosis. The ring-shaped allograft bone demonstrated satisfactory mechanical strength and vertebral fusion without mid-term metallic toxicity.

Knockdown of toll-like receptor 4 signaling pathways ameliorate bone graft rejection in a mouse model of allograft transplantation

Non-union occurring in structural bone grafting is a major problem in allograft transplantation because of impaired interaction between the host and graft tissue. Activated toll-like receptor (TLR) induces inflammatory cytokines and chemokines and triggers cell-mediated immune responses. The TLR-mediated signal pathway is important for mediating allograft rejection. We evaluated the effects of local knockdown of the TLR4 signaling pathway in a mouse segmental femoral graft model. Allografts were coated with freeze-dried lentiviral vectors that encoded TLR4 and myeloid differentiation primary response gene 88 (MyD88) short-hairpin RNA (shRNA), which were individually transplanted into the mice. They were assessed morphologically, radiographically, and histologically for tissue remodeling. Union occurred in autografted but not in allografted mice at the graft and host junctions after 4 weeks. TLR4 and MyD88 expression was up-regulated in allografted mice. TLR4 and MyD88 shRNAs inhibited TLR4 and MyD88 expression, which led to better union in the grafted sites. More regulatory T-cells in the draining lymph nodes suggested inflammation suppression. Local inhibition of TLR4 and MyD88 might reduce immune responses and ameliorate allograft rejection.

Computer-assisted planning and patient-specific guides for the treatment of midshaft clavicle malunions

The surgical treatment of malunions after midshaft clavicle fractures is associated with a number of potential complications and the surgical procedure is challenging. However, with appropriate and meticulous preoperative surgical planning, the surgical correction yields satisfactory results. The purpose of this study was to provide a guideline and detailed overview for the computer-assisted planning and 3-dimensional (3D) correction of malunions of the clavicle. The 3D bone surface models of the pathologic and contralateral sides were created on the basis of computed tomography data. The computer-assisted assessment of the deformity, the preoperative plan, and the design of patient-specific guides enabling compression plating are described. We demonstrate the benefit and versatility of computer-assisted planning for corrective osteotomies of malunions of the midshaft clavicle. In combination with patient-specific guides and compression plating technique, the correction can be performed in a more standardized fashion. We describe the determination of the contact-optimized osteotomy plane. An osteotomy along this plane facilitates the correction and enlarges the contact between the fragments at once. We further developed a technique of a stepped osteotomy that is based on the calculation of the contact-optimized osteotomy plane. The stepped osteotomy enables the length to be restored without the need of structural bone graft. The application of the stepped osteotomy is presented for malunions of the clavicle with shortening and excessive callus formation. The 3D preoperative planning and patient-specific guides for corrective osteotomies of the clavicle may help reduce the number of potential complications and yield results that are more predictable.

Evaluation of the effects of the combination of autologous mesenchymal stem cells and platelet-rich plasma on structural bone allograft healing.

In this study, we evaluated the efficacy of the combination of autologous mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) for enhancing structural allogenic bone graft healing in rabbits. For these experiments segmental bone defects (1.5-2cm) were generated on femoral diaphysis of New Zealand white rabbits and reconstructed via structural allogenic bone grafting and additional intramedullary nail fixation. The structural allografts were subsequently wrapped with Gelfoam containing autologous MSCs and PRP, or PRP alone (control). Grafted periosteal tissues were harvested at 4, 8, and 12weeks post-implantation and subjected to plain radiographic and, histological, as well as real-time quantitative reverse transcription-PCR analysis of bone morphogenic protein (BMP)-2, BMP-4, BMP-7, receptor activator of nuclear factor-kappa B ligand (RANKL), and vascular endothelial growth factor (VEGF) expression. Compared to those in the control group, the animals in the experimental group exhibited significantly higher Taira radiographic scores at 4 and 12weeks after surgery, as well as callus formation. Likewise, these animals exhibited increases in BMP-4 production at 4weeks, RANKL production at 4 and 12weeks, and BMP-2, BMP-7, and VEGF production at 4, 8, and 12weeks. Together, these data suggest that the administration of autologous MSCs and PRP resulted in enhanced healing of structural allogenic bone grafts compared to PRP alone. As such, this combination might comprise an ideal therapy for improving the clinical outcomes of structural allografts.

Effect of Jumbo cups for total hip arthroplasty revision on femoral offset and hip center of rotation

To investigate the change of the femoral offset and hip center of rotation (COR) after using Jumbo cups in total hip arthroplasty (THA) revision. The clinical data of 23 patients who underwent THA revision using Jumbo cups between January 2010 and May 2015 were retrospectively analyzed. Morselized bone graft was performed on 8 cases, morselized bone graft combined with structural bone graft on 10 cases. There were 10 males and 13 females, aged 65.4 years on average (range, 51-77 years). The disease duration was 1-24 years (mean, 8.57 years). The reasons for revision included aseptic loosening in 21 cases and periprosthetic infection in 2 cases. The Harris hip score and visual analogue scale (VAS) were 43.04±5.05 and 5.70±0.97 before operation respectively. According to the Paprosky acetabular defect classification, there were 5 cases of type I, 5 cases of type II A, 3 cases of type II B, 6 cases of type II C, and 4 cases of type III A. The X-ray films showed that the femoral offset was (40.65±4.09) mm for normal side and was (44.04±5.08) mm for affected side at preoperation, showing significant difference ( t=4.098, P=0.000). Ten patients underwent femoral offset reconstruction (43.48%) but 13 patients did not (56.52%) before operation. The COR was reconstructed in 10 cases (43.48%); COR elevation was observed in 11 cases (47.83%), and COR decline in 2 cases (8.69%) before operation. Primary healing of incision was obtained in all patients, with no complication of infection, vascular injury, deep vein thrombosis, dislocation of the joint, or fracture around prosthesis. All the patients were followed up 12-76 months (mean, 22.48 months). The Harris hip score and VAS were 82.09±4.53 and 0.74±0.62 at 1 year after operation respectively, showing significant differences when compared with preoperative scores ( t=37.831, P=0.000; t=22.318, P=0.000). The X-ray films showed that the femoral offset was (43.87±3.57) mm for affected side at 1 year after operation, showing no significant difference when compared with preoperative one ( t=0.250, P=0.805), but significant difference was found between affected side and normal side ( t=5.591, P=0.000). The femoral offset was restored in 16 patients (69.57%) and was not restored in 7 patients (30.43%) after operation. The COR was restored in 15 patients (65.22%) and was not restored in 8 patients (34.78%). Using Jumbo cups or combined with morselized or structural bone graft is effective in restoring hip COR and femoral offset at the maximum limit in THA revision, with good short-term outcome and improved stability of acetabular prosthesis.

Reviziona artroplastika kolena - naše iskustvo

Introduction: Revision knee arthroplasty is not a routine procedure and almost always it is a technically demanding operation. The paradigm in revision total knee arthroplasty is to achieve correct alignment of the components, maintenance of the joint space and ligament balance by providing a stable bone-implant fusion. Metaphyseal bone loss is a crucial problem in revision total knee arthroplasty. The bone loss is due to primary arthroplasty technical errors and design, or problematic removal of the implants. Aim: The aim of this article is to present our experience on total knee revision surgery using tantalum metal cones as a structural bone graft substitute in total arthroplasty failure with gross metaphyseal bone loss categorized by the AORI classification, performed by a specific surgical technique and evaluated by the Knee Society Score (KSS). Material and methods: From 2013 to 2016 at the University Clinic for Orthopedic Surgery in Skopje 21 patient has been treated with revision total knee arthroplasty. Twelve patients had type 1/type 2 bone defects according to AORI, and nine had type 3 bone defect. We used trabecular metal bone graft in type 3 bone defects. A special emphasis is placed on preoperative planning according to the classification system for ligament and soft tissue damage as well as the AORI classification in order to determine the quantity, location and extent of the bone loss. In our series in patients with type 3 deformities, trabecular metal augments were used. This material resembles the human trabecular bone by its cellular structure and elastic characteristics. Results: Preoperatively, all the patients had Knee Society Score below 60, most of them were housebound, experiencing great pain and disability. After six months 95% were rated excellent, and on one year follow up, 89% were rated good or excellent (KSS score above 82, mean score 81.5), 1 patient was marked as poor with a complication-dislocation of the prosthesis. In the follow up period there was no infection. Conclusion: Our results of revision knee arthroplasty by using the trabecular metal augments with at least a year of follow up are excellent according to the KSS compared to the other studies. The disadvantages of the study are mentioned and the need for further investigation is stressed.

The Effects of Autologous Structural Bone Graft without Internal Fixation on Posteromedial Tibial Bone Defect in Primary Total Knee Arthroplasty

The Effects of Autologous Structural Bone Graft without Internal Fixation on Posteromedial Tibial Bone Defect in Primary Total Knee Arthroplasty

Letter Regarding: Prospective, Randomized, Multi-centered Clinical Trial Assessing Safety and Efficacy of a Synthetic Cartilage Implant Versus First Metatarsophalangeal Arthrodesis in Advanced Hallux Rigidus.

Background Although a variety of great toe implants have been tried in an attempt to maintain toe motion, the majority have failed with loosening, malalignment/dislocation, implant fragmentation and bone loss. In these cases, salvage to arthrodesis is more complicated and results in shortening of the ray or requires structural bone graft to reestablish length. This prospective study compared the efficacy and safety of this small (8/10 mm) hydrogel implant to the gold standard of a great toe arthrodesis for advanced-stage hallux rigidus. Methods In this prospective, randomized non-inferiority study, patients from 12 centers in Canada and the United Kingdom were randomized (2:1) to a synthetic cartilage implant or first metatarsophalangeal (MTP) joint arthrodesis. VAS pain scale, validated outcome measures (Foot and Ankle Ability Measure [FAAM] sport scale), great toe active dorsiflexion motion, secondary procedures, radiographic assessment, and safety parameters were evaluated. Analysis was performed using intent-to-treat (ITT) and modified ITT (mITT) methodology. The primary endpoint for the study consisted of a single composite endpoint using the 3 primary study outcomes (pain, function, and safety). The individual subject's outcome was considered a success if all of the following criteria were met: (1) improvement (decrease) from baseline in VAS pain of ≥30% at 12 months; (2) maintenance of function from baseline in FAAM sports subscore at 12 months; and (3) absence of major safety events at 2 years. The proportion of successes in each group was determined and 1-sided 95% confidence interval for the difference between treatment groups was calculated. Noninferiority of the implant to arthrodesis was considered statistically significant if the 1-sided 95% lower confidence interval was greater than the equivalence limit ( Results VAS pain scores decreased significantly in both the implant and arthrodesis groups from baseline at 12 and 24 months. Similarly, the FAAM sports and activity of daily living subscores improved significantly at 12 and 24 months in both groups. First MTP active dorsiflexion motion improvement was 6.2 degrees (27.3%) after implant placement and was maintained at 24 months. Subsequent secondary surgeries occurred in 17 (11.2%) implant patients (17 procedures) and 6 (12.0%) arthrodesis patients (7 procedures). Fourteen (9.2%) implants were removed and converted to arthrodesis, and 6 (12.0%) arthrodesis patients (7 procedures [14%]) had isolated screws or plate and screw removal. There were no cases of implant fragmentation, wear, or bone loss. When analyzing the ITT and mITT population for the primary composite outcome of VAS pain, function (FAAM sports), and safety, there was statistical equivalence between the implant and arthrodesis groups. Conclusion A prospective, randomized (2:1), controlled, noninferiority clinical trial was performed to compare the safety and efficacy of a small synthetic cartilage bone implant to first MTP arthrodesis in patients with advanced-stage hallux rigidus. This study showed equivalent pain relief and functional outcomes. The synthetic implant was an excellent alternative to arthrodesis in patients who wished to maintain first MTP motion. The percentage of secondary surgical procedures was similar between groups. Less than 10% of the implant group required revision to arthrodesis at 2 years. Level of evidence Level I, prospective randomized study.

Technique for Use of Trabecular Metal Spacers in Tibiotalocalcaneal Arthrodesis With Large Bony Defects.

There are many causes of large bone defects in the tibiotalar joint that need to be definitively treated with a tibiotalocalcaneal (TTC) arthrodesis. Some of the challenges of a large defect are its effect on leg length and the complications associated with trying to fill the defect with structural bone graft. We present an operative strategy involving the use of a trabecular metal implant, a TTC nail that utilized 2 forms of compression, and Reamer/Irrigator/Aspirator (RIA) autograft, to address limitations of previous operative approaches and reliably treat this operative challenge.

Occipitocervical Fixation: A Single Surgeon's Experience With 120 Patients.

Occipitocervical junction instability can lead to serious neurological injury or death. Open surgical fixation is often necessary to provide definitive stabilization. However, long-term results are limited to small case series. To review the causes of occipitocervical instability, discuss the indications for surgical intervention, and evaluate long-term surgical outcomes after occipitocervical fixation. The charts of all patients undergoing posterior surgical fixation of the occipitocervical junction by the senior author were retrospectively reviewed. A total of 120 consecutive patients were identified for analysis. Patient demographic characteristics, occipitocervical junction pathology, surgical indications, and clinical and radiographic outcomes are reported. The study population consisted of 64 male and 56 female patients with a mean age of 39.9 years (range, 7 months to 88 years). Trauma was the most common cause of instability, occurring in 56 patients (47%). Ninety patients (75%) were treated with screw/rod constructs; wiring was used in 30 patients (25%). The median number of fixated segments was 5 (O-C4). Structural bone grafts were implanted in all patients (100%). Preoperative neurological deficits were present in 83 patients (69%); 91% of those patients improved with surgery. Mean follow-up was 35.1 ± 27.4 months (range, 0-123 months). Two patients died, and 10 were lost to follow-up before the end of the 6-month follow-up period. Fusion was confirmed in 107 patients (89.1%). The overall complication rate was 10%, including 3 patients with vertebral artery injuries and 2 patients who required revision surgery. Occipitocervical fixation is a durable treatment option with acceptable morbidity for patients with occipitocervical instability. AIS, American Spinal Injury Association Impairment ScaleCVJ, craniovertebral junctionmJOAS, modified Japanese Orthopaedic Association ScaleNLI, neurological level of injurySCI, spinal cord injury.

Multilevel Corpectomy With Anterior Column Reconstruction and Plating for Subaxial Cervical Osteomyelitis.

A retrospective case series. The aim of this study was to evaluate patients with cervical spine osteomyelitis who underwent multilevel (≥2) subaxial corpectomies and anterior column reconstruction and plating. Neglected multilevel subaxial cervical osteomyelitis is a potentially dangerous disease. As it is rare, early radiographic and clinical outcomes after multilevel anterior corpectomy and reconstruction for subaxial cervical osteomyelitis are incompletely defined. Adults who underwent multilevel corpectomy and anterior plating/reconstruction for subaxial cervical osteomyelitis at two institutions were reviewed. Analysis of patient demographics, operative details, and radiographic cervical alignment parameters [segmental kyphosis, cervical lordosis, C2-7 sagittal vertical axis (SVA)] was performed. Nineteen patients [15 males, four females; average age 48 years (20-81 yrs)] met inclusion criteria. The majority had pre-operative neurologic deficits or was immunosuppressed. All were treated with ≥6 weeks of intravenous antibiotics following operation. All had anterior plating/reconstruction with titanium cages (expandable-6; mesh-6) or structural bone graft (fibular allogaft-6; tricortical iliac crest-1). The average number of corpectomies was 2.4 (2-4). The average numbers of levels fused anteriorly was 4.4 (4-6) and posteriorly was 6.3 (4-9). The majority of patients (74%) was treated with an anterior/posterior approach. Average follow-up was 16 ± 9 months. There was significant improvement in all cervical alignment parameters (segmental kyphosis, C2-7 SVA, cervical lordosis). No intraoperative complications occurred and no patient deteriorated neurologically postoperatively. Postoperative complications included anterior cage/graft dislodgement (n = 2), recurrent neck hematomas requiring revision (n = 1), epidural hematoma (n = 1), and wound infection (n = 1). Sixty percent of patients had persistent neurologic dysfunction at final follow-up. None required reoperation for recurrent infection or pseudarthrosis. Although overall prognosis and neurologic recovery are guarded in medically fragile patients with multilevel subaxial cervical osteomyelitis, reconstruction with multilevel (≥2) corpectomy and anterior reconstruction/plating results in excellent restoration of cervical alignment and low rates of recurrent infection and pseudarthrosis. 4.

A Systematic Review With Consensus Expert Opinion of Best Reconstructive Techniques After Osseous En Bloc Spinal Column Tumor Resection.

Systematic literature review and consensus expert opinion. To provide recommendations on reconstructive constructs for large tumor resections of the spinal column. Four questions were studied: (1) What are the best reconstructive options for single versus multilevel resections? (2) Should short segment fixation be considered in primary tumor reconstruction? (3) How should reconstructive techniques differ at various regions of the spine? (4) Does planned postoperative radiation change the fusion strategy? Primary spinal tumors requiring en bloc resection are rare. Most studies focus on disease-free survival and local recurrence rates. Few studies focus on reconstructive options and outcomes with respect to fusion rates and need for revision. A literature search was performed from January 1990 to December 2013. Data were combined and construct survivorship summarized. A survey was administered to international spine tumor surgeons, evaluating reconstructive preferences. The search yielded 381 articles, 12 included in the final analysis. Revision rates for anterior reconstruction were similar for autogenous strut grafts (10%), cages (7.7%), and allograft strut grafts (8.3%). There were two reports of revision from short to long segment constructs and three reports of broken pedicle screws, one requiring revision. Expert survey results revealed that most surgeons preferred cages packed with morcelized allograft and autograft (75%) for anterior reconstruction of single-level vertebrectomies, and strut bone grafting at the cervicothoracic junction (65%) and when more than one vertebrae was resected in the mid-thoracic spine (75%). Surgeons may alter their fusion technique if postoperative radiation is planned. Posterior reconstruction with at least two vertebral levels above and below is recommended. Cages should be used for single-level defects and structural bone graft alone, or in combination with a cage, should be used when spanning a defect greater than two vertebral bodies. Planned postoperative radiation may affect fusion strategy. N/A.

Bone Remodeling in Acetabular Reconstruction Using a Kerboull-Type Reinforcement Device and Structural Bone-Grafting in Total Hip Arthroplasty

BackgroundThe purpose of this study was to identify the long-term durability of the Kerboull-type reinforcement device (KT plate) in acetabular reconstruction for massive bone defects, assessing the remodeling of structural bone grafts. MethodsThis study retrospectively evaluated 106 hips that underwent acetabular reconstruction using a KT plate between November 2000 and December 2010. Thirty-eight primary total hip arthoplasties (THAs) and 68 revised THAs were performed, and the mean duration of clinical follow-up was 8 years (5-14 years). Regarding reconstructing the acetabular bone defects, autografts were used in 37 hips, allografts in 68 hips, and A-W glass ceramics in 2 hips. ResultsOne hip exhibited radiological migration and no revision for aseptic loosening. The mean Merle d'Aubigné Clinical Score improved from 7.5 points (4-12 points) preoperatively to 10.9 points (9-18 points) at the last follow-up. The Kaplan–Meier survival rate for radiological migration of primary and revised THAs at 10 years was 100% and 97% (95% confidence interval: 96%-100%), respectively. Bone remodeling was evaluated using the radiological demarcation at the bone-to-bone interface, and an improvement of 100% in primary THAs and 94% in revised THAs was observed. ConclusionFor massive bone defects, acetabular reconstruction using the KT plate with a structural bone grafting can yield successful results.

Evaluating Outcomes After Midfoot Bone Block Arthrodesis

Category: Midfoot/Forefoot Introduction/Purpose: Midfoot arthrodesis requires a structural graft where bone loss from AVN, osteomyelitis and erosive arthritis is present in the navicular, cuneiform or 1st metatarsal. The goal of this study was to evaluate radiographic outcomes of midfoot bone block arthrodesis. Methods: A retrospective, IRB approved study was completed evaluating midfoot arthrodesis between 2002 and 2014. where structural bone graft was used as part of an arthrodesis of the tarsometatarsal (TMT) joints or the naviculocuneiform (NC) joints or both. Demographic characteristics were obtained including age, body mass index (BMI), diagnosis, diabetes or tobacco use, indication for use of bone block, location of the bone block, and type of graft used. Radiographic data collected included time to union, the number of patients in which union was obtained, and graft length Results: Over a 12-year period, there were a total of 33 with an average age of 57.9 years, and included 20 females and 13 males with an average BMI of 29. The average length of follow up was 24 months. The most common diagnoses was erosive midfoot arthritis (11) and prior navicular fracture associated with AVN (9). Structural allograft was used in all patients. (first TMT (10), talocuneiform (9), other combinations (14)). Various types of biologic agents were used in 20 of 33 arthrodeses. Radiographic evidence of union was found in 21/33 patients (63.6%) at an average of 4.7 months after surgery. Twelve patients developed a nonunion. The risk factors for nonunion include age &gt; 50, the presence of erosive osteoarthritis, AVN of the navicular and lack of use of biologic stimulation. There was no correlation between the presence of diabetes, a prior history of infection or prior history of trauma and development of nonunion. Conclusion: The radiographic fusion rate of patients undergoing large structural midfoot bone graft arthrodesis was 63.6% with radiographic evidence of healing present in this group at 4.77 months after surgery. This is the first known study reporting on radiographic outcomes of structural bone graft arthrodesis of the midfoot. The rate of fusion seen here is slightly better compared with recent studies evaluating healing of large defects using femoral head structural allografts. Nonetheless, the risk of non-union remains far greater than when an in situ arthrodesis of these same joints are performed.

The Biomechanical Evaluation of Revision First Metatarsophalangeal Arthrodesis

Category: Midfoot/Forefoot Introduction/Purpose: First metatarsophalangeal (MP) arthrodesis in the setting of bone loss is a difficult problem. Bone loss may compromise stability of implant fixation. Union rates may be adversely affected by these circumstances. The primary goals of this cadaveric, biomechanical study were as follows: 1) To investigate stiffness of a dual mini-plate construct versus a standard MP arthrodesis plate in the setting of severe bone loss, 2) To evaluate arthrodesis interface motion when an interpositional graft is used. Methods: Twelve matched pairs of fresh, frozen cadaveric foot/ankle specimens were utilized in this study. Pairs were randomized to fixation constructs via computerized randomization (Excel, Microsoft, WA). Within a matched pair one construct used the dual mini plate fixation technique while the other was secured with a standard MP arthrodesis plate. (Fig 1) A revision MP fusion construct with structural bone graft was simulated on six of the specimen pairs, while the remaining constructs did not utilize any interpositional graft. Results: Based on load to failure data, there were no differences between the various constructs in terms of stiffness. There was a high degree of calculated plantar gapping with the placement of a bone block, irrespective of the fixation type. In the presence of an interpositional graft, regardless of plating construct, the calculated proximal interface strain was an average of 26%. Subsequently, failure was most commonly seen at the proximal interface of the interpositional graft group (83%, 10 out of 12). Distal interface strain in the interpositional graft group was calculated to be 11%. The proximal interface strain was significantly larger than the distal interface strain (26% vs 11%) (p &lt; 0.05). Conclusion: Although no construct differences were observed in terms of stiffness, the dual mini-plate is an alternative option for fixation when asymmetric bone loss is either seen on the phalangeal or metatarsal head side. The high degree of plantar gapping of the proximal interface with the placement of the bone block may have implications for healing potential across the arthrodesis site.

Subtalar Distraction Arthrodesis with Fresh Frozen Femoral Neck Allograft: A Retrospective Case Series.

Subtalar joint distraction arthrodesis has been well reported with use of structural iliac crest or local autologous bone graft for malunited calcaneal fractures. Early reports for structural allograft did not yield good, consistent results, leading to a subsequent lack of recommendation in previous literature. Newer studies have had promising results utilizing femoral allograft as an alternative to autogenous bone graft. We performed a retrospective chart review on 10 patients (12 feet) undergoing subtalar joint distraction arthrodesis with femoral neck allograft for malunited calcaneal fractures. The primary aim of this study was to report on successful union rates and, in addition, outline any consistent complications. Twelve of the 12 procedures (100%) yielded successful fusion with a mean final follow-up of 7.7 months (range = 2.2-35.1 months). The mean increase in talocalcaneal height was 4 mm (range = 2-6 mm). The overall complication rate was 16.6%, including one superficial wound complication that healed uneventfully and one hardware removal. In conclusion, the current study reports a 100% successful fusion rate with interpositional structural femoral neck allograft in treatment for malunited calcaneal fractures. Therapeutic, Level IV: Case series.

Pediatric occipitocervical fixation: radiographic criteria, surgical technique, and clinical outcomes based on experience of a single surgeon.

OBJECTIVE If left untreated, occipitocervical (OC) instability may lead to serious neurological injury or death. Open internal fixation is often necessary to protect the neurovascular elements. This study reviews the etiologies for pediatric OC instability, analyzes the radiographic criteria for surgical intervention, discusses surgical fixation techniques, and evaluates long-term postoperative outcomes based on a single surgeon's experience. METHODS The charts of all patients < 18 years old who underwent internal OC fixation conducted by the senior author were retrospectively reviewed. Forty consecutive patients were identified for analysis. Patient demographic data, OC junction pathology, radiological diagnostic tools, surgical indications, and outcomes are reported. RESULTS The study population consisted of 20 boys and 20 girls, with a mean age of 7.3 years. Trauma (45% [n = 18]) was the most common cause of instability, followed by congenital etiologies (37.5% [n = 15]). The condyle-C1 interval had a diagnostic sensitivity of 100% for atlantooccipital dislocation. The median number of fixated segments was 5 (occiput-C4). Structural bone grafts were used in all patients. Postsurgical neurological improvement was seen in 88.2% (15/17) of patients with chronic myelopathy and in 25% (1/4) of patients with acute myelopathy. Preoperatively, 42.5% (17/40) of patients were neurologically intact and remained unchanged at last follow-up, 42.5% (17/40) had neurological improvement, 12.5% (5/40) remained unchanged, and 2.5% (1/40) deteriorated. All patients had successful fusion at 1-year follow-up. The complication rate was 7.5% (3/40), including 1 case of vertebral artery injury. CONCLUSIONS Occipitocervical fixation is safe in children and provides immediate immobilization, with excellent survival and arthrodesis rates. Of the radiographic tools evaluated, the condyle-C1 interval was the most predictive of atlantooccipital dislocation.