Functional Limb Salvage Research Articles

Ankle Arthrodesis With Structural Grafts Can Work for the Salvage of Failed Total Ankle Arthroplasty.

Background. Treatment options after failed total ankle arthroplasty (TAA) are limited. This study reports midterm outcomes and radiographic results in a single-surgeon group of patients who have undergone ankle arthrodesis with intramedullary nail fixation and structural allograft augmentation following failed TAA. Methods. A retrospective review on patients who underwent failed TAA revision with structural femoral head allograft and intramedullary tibiotalocalcaneal (TTC) nail fixation was completed. Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) outcome scores, and radiographs were obtained at each visit with 5-year follow-up. Results. Five patients were followed to an average of 5.2 years (range 4.7-5.6). Enrollment FFI was 34.82 (range 8.82-75.88); at midterm follow-up it was 20.42 (range 0-35.38). Enrollment AOFAS scores averaged 66.6 (range 61-77); at midterm follow-up it was 70.33 (range 54-88). Radiographs showed union in 4 of 5 patients at enrollment and 2 of 3 patients at midterm. Conclusions. Utilization of TTC fusion with femoral head allograft is a salvage technique that can produce a functional limb salvage. Our results show continued improvement in patient-reported outcomes, with preservation of limb length and reasonable union rate. Levels of Evidence: Therapeutic, Level II: Prospective, comparative trial.

Evaluation of materials used for vascular anastomoses using shear wave elastography

Cardiovascular disease is the leading cause of mortality in the United States. Peripheral artery disease (PAD) affects a substantial portion of the elderly population (>70 years). PAD can be symptomatic or asymptomatic, and treatment is directed towards improving functional vessel patency and limb salvage. Revascularization surgical treatments are needed in some cases, and it is not always possible to use autologous veins for vascular grafting. In this case, synthetic materials may be used. Synthetic materials such as expanded polytetrafluoroethylene (ePTFE) and poly (ethylene terephthalate) (Dacron) have been used. These materials are much stiffer compared to normal arterial vessels so developing alternative materials is an active area of research. One such potential material is a p olyvinyl alcohol cryogel reinforced arterial model (PRAM). In this study we used shear wave elastography (SWE) techniques to compare the mechanical behavior of excised aortas and anastomoses formed between the aortas and the Dacron, ePTFE, and PRAM materials. Different initial longitudinal strains (0%–40%) and transmural pressures (20–180 mmHg) were used to test a wide range of parameters that are within physiological ranges. We found that the PRAM materials had similar mechanical behavior in terms of group velocity measured in the vessel wall with respect to the excised aortas compared to the Dacron and ePTFE that had higher values of group velocity. The ratios of the group velocity for the PRAM material with respect to the aortas ranged from 0.83 to 1.13 where the Dacron and ePTFE had ranges of 1.12–2.22 and 1.91–3.10 for the same stretch and pressure ranges. The PRAM materials provide an alternative vascular material with better mechanical matching with excised aortas.

Study of risk factors affecting the limb salvage in patients with lower extremity arterial trauma

Background: Vascular injury in extremity is a complication of both blunt and penetrating trauma. In Indian scenario, patients generally present late to the tertiary care center with mangled extremity for treatment. The aim of the study is to assess the risk factors affecting the outcome in the management of patients with lower extremity arterial trauma. Materials and Methods: A single-center, observational study was conducted at Sir Ganga Ram Hospital, New Delhi, from January 2013 to June 2017. Sixty patients of lower extremity arterial trauma who underwent revascularization were included and followed up for 6 months. All the risk factors (mode/mechanism of injury, time since injury, compartment syndrome, mangled extremity severity score [MESS], etc.,) and limb salvage were assessed at 6 months. Statistical analysis was performed using Chi-square test and Fisher's exact test. Results: Majority of the patients presented late (6–24 h) of injury and had high mean MESS (7.85). The most common mechanism of injury was blunt trauma (83.3%), and popliteal artery (72%) was the most commonly injured artery. Limb salvage was achieved in 75% of the patients. Time since injury and MESS score affected the limb salvage significantly. On multivariate analysis, MESS score was the single independent factor which affected the limb salvage (95% confidence interval, 0.231–0.769, P = 0.005). Conclusions: MESS is the most important predictors for limb salvage. Multidisciplinary team approach with timely diagnosis and immediate repair is the key to the ultimate goal of functional limb salvage.

Outcomes of limb and life in patients with acute lower limb ischema presenting before and after the “golden six hours”

Background: Acute limb ischemia (ALI) is any sudden decrease in limb perfusion causing a potential threat to limb viability. It is generally accepted that in a patient without underlying arterial disease who develops an acute arterial blockage has approximately six hours for revascularisation before irreversible damage occurs. This study endeavoured to analyse and evaluate the causes and clinical outcome of acute lower limb ischemia.Methods: 80 successive patients visiting Jain Institute of Vascular Sciences, Bangalore who were diagnosed to have ALI were included in this prospective study. Thromboembolectomy was performed in 48% of patients, 9% of patients were managed with anticoagulation alone, 8% of patients were treated by catheter directed thrombolysis and primary amputation was inevitable in 16 patients of class III ischemia.Results: All the five patients who presented within the golden six hours survived and their limbs could be salvaged without any morbidity. Even in patients with delayed presentation but viable limb (47 patients) functional limb salvage was possible in 39 patients (82.9%). Overall there was 72.73% limb salvage and 27.27% patients underwent amputation. There was a mortality rate of 13.16% in the study.Conclusions: Overall there was 72.73% limb salvage and 27.27% patients underwent amputation. Revascularization within six hours is ideal (only 6.25% of patients in our study); however, in delayed presentation (93.75%), physiological state of the limb, rather than elapsed time from onset of occlusion will determine the operability. Late revascularization may thus be indicated and is often successful if limb still exhibits signs of viability.

Successful limb salvage through staged bypass combined with free gracilis muscle transfer for critical limb ischemia with osteomyelitis after failed endovascular therapy

BackgroundCritical limb ischemia with osteomyelitis is so difficult to treat that even appropriate revascularization and wound therapy cannot achieve limb salvage because of uncontrollable infection. It is still difficult to judge the possibility of limb salvage before revascularization.Case presentationA 73-year-old male complained of a small ulcer on his left toe, which was treated with multiple endovascular therapy. After failed endovascular therapy, he suffered extensive tissue loss with tibial osteomyelitis. We carried out staged surgery that was composed of dual bypass to the sural artery and posterior tibial artery. After intensive debridement and wound care, insertion of a subsequent free gracilis muscle flap to cover the exposed tibial bone was performed, achieving functional limb salvage.ConclusionEven in the threatened limb with extensive tissue loss and osteomyelitis, intensive and multidisciplinary treatment with staged revascularization, muscle transfer, and appropriate wound care achieved functional limb salvage.

Ankle Arthrodesis with Structural Grafts Can Work for the Salvage of Failed Total Ankle Replacement

Category: Ankle, Ankle Arthritis Introduction/Purpose: Surgical treatment options after failed total ankle replacement (TAR) are limited to revision total ankle replacements, revision bone block interposition arthrodesis, or amputation. In patients where revision TAR is not an option and limb salvage is desired, conversion to an ankle arthrodesis can provide a stable, plantigrade foot. Revision arthrodesis is challenged by significant bone loss with removal of the TAR implant. The purpose of this study was to report midterm outcomes and radiographic results in a single surgeon’s group of patients who have undergone revision ankle arthrodesis with intramedullary nail fixation and structural allograft augmentation following failed TAR. Methods: Institutional review board approval was obtained for this study. A retrospective chart and radiographic review was performed. Patients with a minimum follow-up of 1 year who underwent failed TAR revision with structural femoral head allograft and intramedullary tibiotalocalcaneal (TTC) nail fixation were included. Patients with less than 1-year follow-up and alternative fixation or graft constructs were excluded from the study. Data were collected upon enrollment visit and again at midterm follow-up ranging from 3-7 years post-operatively. Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) outcomes scores and radiographs were obtained at each visit. Primary outcomes of interest were the rate of limb salvage and patient reported outcome scores. Secondary outcomes include limb length correction and the fate of the structural allograft. Results: Five patients were available for enrollment. Average age at surgery was 63.2 (range 56-69) years. Enrollment visits averaged 1.68 years post-operative (range 0.95 - 3.78). Midterm follow-up was at an average of 5.2 years (range 4.7-5.6). Upon enrollment average FFI was 34.82 (range 8.82-75.88) and at midterm follow-up was 20.42 (range 0-35.38). AOFAS scores upon enrollment averaged 66.6 (range 61-77) and at midterm follow-up averaged 70.33 (range 54-88). Radiographic results show union in 4 of 5 patients at enrollment and in 2 of 3 patients upon midterm follow-up. Average limb length discrepancy at enrollment was 1.4 cm (range 0.5 - 2.0) and 1.6 cm (range 0.2 – 2.4) at midterm follow-up. Conclusion: Conversion of failed TAR to TTC fusion with femoral head allograft is a salvage technique that can lead to a functional arthrodesis and limb salvage in a situation where options are challenging. Our results show continued improvement in patient reported outcomes scores moving from short-term to midterm follow-up with preservation of limb length and no trend towards structural allograft resorption.

Plastic Surgery Challenges in War Wounded I: Flap-Based Extremity Reconstruction

Scope and Significance: Reconstruction of traumatic injuries requiring tissue transfer begins with aggressive resuscitation and stabilization. Systematic advances in acute casualty care at the point of injury have improved survival and allowed for increasingly complex treatment before definitive reconstruction at tertiary medical facilities outside the combat zone. As a result, the complexity of the limb salvage algorithm has increased over 14 years of combat activities in Iraq and Afghanistan. Problem: Severe poly-extremity trauma in combat casualties has led to a large number of extremity salvage cases. Advanced reconstructive techniques coupled with regenerative medicine applications have played a critical role in the restoration, recovery, and rehabilitation of functional limb salvage. Translational Relevance: The past 14 years of war trauma have increased our understanding of tissue transfer for extremity reconstruction in the treatment of combat casualties. Injury patterns, flap choice, and reconstruction timing are critical variables to consider for optimal outcomes. Clinical Relevance: Subacute reconstruction with specifically chosen flap tissue and donor site location based on individual injuries result in successful tissue transfer, even in critically injured patients. These considerations can be combined with regenerative therapies to optimize massive wound coverage and limb salvage form and function in previously active patients. Summary: Traditional soft tissue reconstruction is integral in the treatment of war extremity trauma. Pedicle and free flaps are a critically important part of the reconstructive ladder for salvaging extreme extremity injuries that are seen as a result of the current practice of war.

Failed Agility™ LP Total Ankle Replacement Salvaged with Tibio-Talo- Calcaneal Arthrodesis and Vascularized Pedicled Medial Malleolus and Fibula Onlay Bone Grafts

Controversy exists regarding the most predictable salvage for failed total ankle replacement. Revision total ankle replacement with soft-tissue release/reconstruction or explantation with tibio-talo-calcaneal arthrodesis with bulk structural allograft are the most commonly performed approaches. Tibio-talo-calcaneal arthrodesis with bulk structural allograft has a high complication rate; however, augmentation with vascularized pedicled onlay bone grafts may improve osseous union and functional limb salvage. This manuscript presents the revision of a failed Agility™ LP total ankle replacement system with severe >45° varus ankle deformity that was salvaged with tibio-talocalcaneal arthrodesis, bulk femoral head structural allograft and vascularized pedicled medial malleolus and fibula onlay bone grafts. At short-term 1.5-years follow-up the patient had a well-balanced and painless foot/ankle and return of a functional lower limb.

Pediatric lower extremity sarcoma reconstruction: A review of limb salvage procedures and outcomes

In recent years, dramatic advances in the multidisciplinary treatment of pediatric sarcoma have resulted in significant improvement in the long-term survival of the patient. Thus, following tumor resection, significant effort has gone into limb salvage and improving functional outcomes. Plastic surgeons, in conjunction with orthopedic surgeons, are using techniques in microvascular free-tissue transfer and rotational flap surgery to preserve limb length. This study presents a review of the current reconstructive strategies and the oncologic, surgical, and functional outcomes in this population. Using the Pubmed and Cochrane Library databases, studies describing lower extremity plastic surgical reconstruction were identified following pediatric lower extremity sarcoma resection. This study included those studies which described reconstructive techniques, oncologic and functional outcomes, and surgical complications. A total of nine articles were identified, yielding 96 pediatric patients. The most common procedures performed were free fibular flaps (53 patients) followed by pedicled muscle flaps (31 patients). A total of 72 of 96 patients (75%) achieved independent ambulation, and an additional 19 patients (20%) ambulated with assistance. There were only three (3%) amputations. A total of 13 patients died from metastatic disease (14%). Plastic surgery procedures play an increasingly important role in pediatric lower extremity sarcoma reconstruction and functional limb salvage. Published series are limited in number and case volume; to date, no systematic review has been published. The existing data emphasize the role of microvascular free-fibula transfer as well as local muscle flap coverage in preserving limb length and function, with minimal risk of local recurrence and need for amputation.

Fucoidan protects mesenchymal stem cells against oxidative stress and enhances vascular regeneration in a murine hindlimb ischemia model

BackgroundMesenchymal stem cells (MSCs) have the potential to differentiate into multiple cell lineages. Given this potential for tissue regeneration, MSC-based therapeutic applications have been considered in recent years. However, ischemia-induced apoptosis has been reported to be one of the main causes of MSC death following transplantation. The primary objective of this study was to determine whether a natural antioxidant, fucoidan, could protect MSCs from ischemia-induced apoptosis in vitro and in vivo. Furthermore, we investigated the mechanism of action of fucoidan's anti-ischemic effect in MSCs. Methods and resultPre-treatment with fucoidan (10μg/mL) suppressed the increase in H2O2-induced reactive oxygen species (ROS) levels and drastically reduced apoptotic cell death in MSCs. Fucoidan inhibited the activation of the pro-apoptotic proteins p38-mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK), and caspase-3, and augmented the expression of the anti-apoptosis protein cellular inhibitor of apoptosis (cIAP). Moreover, fucoidan significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the Akt pathway, resulting in enhanced cell survival. In a murine hindlimb ischemia model, transplanted fucoidan-treated MSCs showed significantly enhanced cell survival and proliferation in ischemic tissues. Functional recovery and limb salvage also remarkably improved in mice injected with fucoidan-stimulated MSCs compared with mice injected with non-stimulated MSCs. ConclusionTaken together, these results show that fucoidan protects MSCs from ischemia-induced cell death by modulation of apoptosis-associated proteins and cellular ROS levels through regulation of the MnSOD and Akt pathways, suggesting that fucoidan could be powerful therapeutic adjuvant for MSC-based therapy in ischemic diseases.

The sulfated polysaccharide fucoidan rescues senescence of endothelial colony-forming cells for ischemic repair.

The efficacy of cell therapy using endothelial colony-forming cells (ECFCs) in the treatment of ischemia is limited by the replicative senescence of isolated ECFCs in vitro. Such senescence must therefore be overcome in order for such cell therapies to be clinically applicable. This study aimed to investigate the potential of sulfated polysaccharide fucoidan to rescue ECFCs from cellular senescence and to improve in vivo vascular repair by ECFCs. Fucoidan-preconditioning of senescent ECFCs was shown by flow cytometry to restore the expression of functional ECFC surface markers (CD34, c-Kit, VEGFR2, and CXCR4) and stimulate the in vitro tube formation capacity of ECFCs. Fucoidan also promoted the expression of cell cycle-associated proteins (cyclin E, Cdk2, cyclin D1, and Cdk4) in senescent ECFCs, significantly reversed cellular senescence, and increased the proliferation of ECFCs via the FAK, Akt, and ERK signaling pathways. Fucoidan was found to enhance the survival, proliferation, incorporation, and endothelial differentiation of senescent ECFCs transplanted in ischemic tissues in a murine hind limb ischemia model. Moreover, ECFC-induced functional recovery and limb salvage were markedly improved by fucoidan pretreatment of ECFCs. To our knowledge, the findings of our study are the first to demonstrate that fucoidan enhances the neovasculogenic potential of ECFCs by rescuing them from replicative cellular senescence. Pretreatment of ECFCs with fucoidan may thus provide a novel strategy for the application of senescent stem cells to therapeutic neovascularization.

Intraoperative extracorporeal autogenous irradiated tendon grafts for functional limb salvage surgery of soft tissue sarcomas of the wrist and hand.

BackgroundIn patients with soft tissue sarcoma of the wrist and hand, limb salvage operation is extremely challenging for surgeons in attempting a complete tumor resection with negative surgical margins. In this study, we report four patients with soft tissue sarcoma of the wrist and hand treated by limb salvage operation with intraoperative extracorporeal autogenous irradiated tendon grafts.MethodsThe patients were all male, and the mean age at the time of surgery was 45 years. Histological diagnoses included clear cell sarcoma in two patients, synovial sarcoma in one, and angiosarcoma in one. All four patients had high grade tumors, wherein three had American Joint Committee on Cancer (AJCC) stage III disease and one with AJCC stage IV disease. The tumors were resected en bloc with involved tendons. The tendons were isolated from the resected tissues, irradiated ex vivo, and re-implanted into the host tendons. In one patient, the bone was resected additionally because of tumor invasion to the bone. Hand function was evaluated using Musculoskeletal Tumor Society (MSTS) rating system.ResultsOf the four patients, three died of distant metastatic disease. The remaining patient lives and remains disease-free. The mean follow-up period was 33 months. One patient had local recurrence outside the irradiated graft at 20 months after surgery. The functional rating was 22. Lower scores were seen in patients with reconstruction of flexor tendons than extensor tendons.ConclusionsLimb salvage operation with intraoperative extracorporeal autogenous irradiated tendon grafts is an acceptable method in selected patients with soft tissue sarcoma of the wrist and hand.

Surgical management of Charcot neuroarthropathy.

Charcot neuroarthropathy is one of the more devastating complications of diabetes. It is a progressive, destructive condition that is characterized by acute fracture, dislocation, and joint destruction in weight-bearing neuropathic foot. In its acute phase, it is often misdiagnosed and can lead to several deformities such as ulcerations and amputation. Early diagnosis and management is, therefore, imperative to avoid rapid progression. Review current literature on the diagnosis and management of diabetic patients with Charcot neuroarthropathy. Narrative review. Particular attention is directed to the role of surgical management in achieving long term osseous stability and alignment so that appropriate footwear and bracing are possible. Charcot neuroarthropathy is a serious and potentially limb-threatening lower extremity late complication of diabetes. Correct timing, adequate fixation and a long post-operative weightbearing period are key to optimizing reconstructive surgery. Primary care providers who treat diabetic patients should be cognizant of the possible complication among patients with diabetic neuropathy of which includes Charcot neuroarthropathy. In this paper, discussion is provided on a rational approach to functional limb salvage with various surgical techniques when non-operative management fails.

Pediatric Lower Extremity Sarcoma Reconstruction

INTRODUCTION: Dramatic advances in the multidisciplinary treatment of pediatric sarcoma have been made in recent years resulting in significantly improved long-term survival. As survival has increased, greater effort has been made towards limb salvage and improving functional outcomes following tumor resection. Plastic surgeons in conjunction with orthopedic surgeons are applying techniques in microvascular free tissue transfer and rotational flaps to preserve limb length. METHODS: Studies describing lower extremity reconstruction following pediatric lower extremity sarcoma resection were identified by PubMed literature search. Those studies which described reconstructive techniques, oncologic and functional outcomes, and surgical complications were included. RESULTS: A total of 10 articles were identified, yielding 119 total patients. Two articles presented a wider scope of inquiry but sufficient sub-group detail to permit inclusion and three articles were single patient case reports. The average patient age ranged 9 to 14 years and overall age range was 15 weeks to 19 years. The average follow-up ranged 27 to 63 months and overall follow-up range was 0 to 168 months. The most common procedures performed were pedicled gastrocnemius +/- soleus flap (58 patients) and free fibular flap (40 patients). Eighty eight out of 116 patients (76%) achieved independent ambulation, and an additional ten patients (9%) were ambulatory with assistance. There were only three (2.5%) amputations. Seven patients died from metastatic disease (5.9%). CONCLUSIONS: Plastic surgery procedures play an increasingly important role in pediatric lower extremity sarcoma reconstruction and functional limb salvage. Published series are limited in number and case volume, and no systematic review has been published to date. However, the existing data emphasizes the role for local muscle flap coverage as well as microvascular free fibula transfer in preserving limb length and function, with a minimal risk of local recurrence and need for amputation.

Is claviculo pro humeri of value for limb salvage of pediatric proximal humerus sarcomas?

There are several options for proximal humerus reconstruction in young children after resection of a malignant tumor and no one technique has been definitively shown to be superior to others, leaving the decision to surgeon and patient choice. Claviculo pro humeri (CPH) is a biologic reconstruction of the proximal humerus using the patient's ipsilateral clavicle as a rotational osseous flap. CPH represents a potential option for this complicated clinical problem in very young children, but little is known about it because the indications for its use are so uncommon. The purposes of this study were to (1) assess the oncologic outcomes of CPH at a minimum of 2 years in a small series of patients; (2) elicit the complications associated with this procedure; and (3) show the Musculoskeletal Tumor Society (MSTS) functional score of these patients. Four patients (average age, 5 years 11 months; range, 4 years 5 months to 8 years 9 months at the time of surgery) were treated with CPH for reconstruction after resection of a proximal humerus sarcoma; this represented all of the patients treated with this approach for this problem between January 2008 and April 2011 at one institution. During this period, the general indications for using CPH were the need to reconstruct a proximal humerus defect in a child younger than 10 years of age. During this time, CPH was used for all patients treated for proximal humerus sarcomas meeting these criteria. Patient demographics, diagnosis, tumor size and extent, operative details, radiographs and MRIs, complications, and functional outcomes were assessed. All are alive with no evidence of disease at a minimum followup of 31 months (average, 43 months; range, 31-58 months). Two patients developed nonunion and underwent revision surgery. Osseous union and a stable neoshoulder articulation were ultimately obtained in all patients. Limited shoulder motion was the only functional deficit noted with forward elevation ranging between 30° and 90°. MSTS functional scores were excellent with a range of 87% to 90%. This is a rarely used procedure in North America but we achieved functional limb salvage in all four patients. Consistent with prior literature, nonunion was the major complication in this series. The two nonunions were successfully treated without interruption of chemotherapy or significant bone graft donor site morbidity. Based on these results, the authors suggest that this procedure is a reasonable reconstruction option to consider after proximal humerus resection in patients younger than 10 years of age. Further followup will be required to assess long-term results and to determine how this procedure compares with the alternatives. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Patient-based outcomes and quality of life after salvageable wartime extremity vascular injury

To date, contemporary studies on wartime vascular trauma have focused on acute management strategies and early results, with no characterization of enduring functional limb salvage or its relation to quality of life. The objective of this study was to describe long-term, patient-based quality of life and function after extremity vascular injury (EVI). The Joint Theater Trauma Registry was queried for U.S. troops with EVI. Injury and management data was obtained and the Medical Outcomes Study Short Form 36 (SF-36) Health Survey administered after patient contact and consent. Demographic, injury, and management variables were analyzed and examined for correlation with the primary end points of favorable or unfavorable outcome defined by SF-36 Mental (MCS) or Physical Component Summary (PCS) scores of >42 or <42 (effect size ≥ 0.8). Surveys were completed by 214 patients, who were a median age of 25 years (range, 19-52 years). The Injury Severity Score was 15.3 ± 8.6 and the Mangled Extremity Severity Score was 5.65 ± 1.4. Amputation-free survival was 84% at mean follow-up of 61 ± 24 months. Overall SF-36 PCS and MCS scores were 43.0 ± 9.2 and 46.6 ± 12.4, respectively, with 92 respondents (43%) reporting favorable outcomes on both MCS and PCS. On multivariate analysis, older age, severe extremity injury (Mangled Extremity Severity Scores ≥ 7), and chronic pain were predictive of unfavorable physical outcomes (P < .05). Presence of pain, nerve injury, and junior rank (<E7) were predictive of unfavorable MCS scores (P < .05). Higher educational background (baccalaureate or above) was associated with favorable outcome (P < .05). This study reports the first long-term patient-centered outcomes data after wartime EVI. At 5 years after injury, quality-of-life measures are reduced compared with national norms. Understanding high-risk characteristics, both demographic- and injury-specific, that are associated with unfavorable outcomes will help guide future acute management and long-term recovery strategies.

Tibiotalocalcaneal Arthrodesis With Bulk Femoral Head Allograft for Salvage of Large Defects in the Ankle

Tibiotalocalcaneal arthrodesis in patients with large segmental bony defects presents a substantial challenge to successful reconstruction. These defects typically occur following failed total ankle replacement, avascular necrosis of the talus, trauma, osteomyelitis, Charcot, or failed reconstructive surgery. This study examined the outcomes of tibiotalocalcaneal (TTC) arthrodesis using bulk femoral head allograft to fill this defect. Thirty-two patients underwent TTC arthrodesis with bulk femoral head allograft. Patients who demonstrated radiographic union were contacted for SF-12 clinical scoring and repeat radiographs. Patients with asymptomatic nonunions were also contacted for SF-12 scoring alone. Preoperative, intraoperative, and postoperative factors were analyzed to determine positive predictors for successful fusion. Sixteen patients healed their fusion (50% fusion rate). Diabetes mellitus was found to be the only predictive factor of outcome; all 9 patients with diabetes developed a nonunion. In this series, 19% of the patients went on to require a below-knee amputation. Although the radiographic fusion rate was low, when the 7 patients who had an asymptomatic nonunion were combined with the radiographic union group, the overall rate of functional limb salvage rose to 71%. TTC arthrodesis using femoral head allograft should be considered a salvage procedure that is technically difficult and carries a high risk for complications. Patients with diabetes mellitus are at an especially high risk for nonunion. Level IV, retrospective case series.

Characterization of a composite injury model of severe lower limb bone and nerve trauma

Severe extremity trauma often results in large zones of injury comprising multiple types of tissue and presents many clinical challenges for reconstruction. Considerable investigation is ongoing in tissue engineering and regenerative medicine therapeutics to improve reconstruction outcomes; however, the vast majority of musculoskeletal trauma models employed for testing the therapeutics consist of single-tissue defects, offering limited utility for investigating strategies for multi-tissue repair. Here we present the first model of composite lower limb bone and nerve injury, characterized by comparison to well-established, single-tissue injury models, using biomaterials-based technologies previously demonstrated to show promise in those models. Quantitative functional outcome measures were incorporated to facilitate assessment of new technologies to promote structural and functional limb salvage following severe extremity trauma. Nerve injury induced significant changes in the morphology and mechanical properties of intact bones. However, BMP-mediated segmental bone regeneration was not significantly impaired by concomitant nerve injury, as evaluated via radiographs, microcomputed tomography (μCT) and biomechanical testing. Neither was nerve regeneration significantly impaired by bone injury when evaluated via histology and electrophysiology. Despite the similar tissue regeneration observed, the composite injury group experienced a marked functional deficit in the operated limb compared to either of the single-tissue injury groups, as determined by quantitative, automated CatWalk gait analysis. As a whole, this study presents a challenging, clinically relevant model of severe extremity trauma to bone and nerve tissue, and emphasizes the need to incorporate quantitative functional outcome measures to benchmark tissue engineering therapies.

Reperfusion strategies in the management of extremity vascular injury with ischaemia

Extremity injury with ischaemia is the most common pattern of vascular trauma and is a challenge for surgeons who must make decisions about the timing and mechanism of limb reperfusion. In modern military conflicts, effective use of limb tourniquets and rapid transport of the injured have increased the number of casualties who reach a medical service with potentially survivable vascular trauma. This report provides a review of extremity ischaemia and reperfusion following vascular trauma. A review was undertaken of extremity vascular injury with ischaemia, including a focus on adjuncts aimed at reducing reperfusion injury and improving neuromuscular recovery and limb salvage. Findings from basic and clinical research support the need to restore perfusion to an ischaemic limb as soon as possible in order to achieve optimal neuromuscular recovery. Large-animal studies demonstrate that haemorrhagic shock worsens the impact of ischaemia on the neuromuscular structures of the limb and reduces the ischaemic threshold to as little as 1 h. Surgical adjuncts such as vascular shunts, fasciotomy, regional limb cooling and ischaemic conditioning may reduce the severity of ischaemic injury. Medical therapies have also been described including hypertonic saline, statins and ethyl pyruvate, which reduce the inflammatory response following limb reperfusion. Contemporary translational research refutes a casual approach to extremity vascular injury with ischaemia, instead emphasizing expedited reperfusion. Surgical and medical adjuncts exist to expedite reperfusion and mitigate reperfusion injury. Additional research and development of these adjuncts is necessary to improve quality or functional limb salvage after vascular trauma.

The Ischemic Threshold of the Extremity

Military efforts to limit ischemic time and reperfusion injury are being investigated with a focus on functional limb salvage as opposed to the more historic statistical salvage, since a dysfunctional limb may be a worse outcome than amputation. Translatable animal research, supported by reports from forward deployed surgeons in the field, is needed to improve care. Current studies have determined the threshold for meaningful recovery is less than 6 hours. Attempts at modeling vascular injury and ischemia reperfusion can be divided into 2 categories: chronic ischemia that mimics human age related disease and acute vascular injury that represents traumatic injury. A swine model to evaluate battlefield injuries and scenarios encountered in traumatic extremity vascular injury with a focus on functional limb salvage has been developed. Future endeavors should focus on understanding the factors that affect ischemic threshold as well as testing therapeutic and physical maneuvers to prolong this threshold.