Ankle arthrodesis or total ankle arthroplasty surgery for end stage ankle arthritis, which is best? A review of the best available evidence.

BACKGROUND: End Stage Ankle Arthritis (ESAA) causes pain and dysfunction. It is treated effectively with Total Ankle Arthroplasty (TAA) or Ankle Arthrodesis (AA). Currently there is no consensus on which surgical procedure is superior. This paper will provide a systematic review of all published high-quality studies directly comparing TAA and AA for the surgical treatment of ESAA to determine superiority. METHODS: A comprehensive literature review of the highest quality studies published that directly compare clinical outcomes of TAA and AA for surgical treatment of ESAA was conducted. Each study was assigned a Level of Evidence (LOE) rating (I-III) and then summarized to assign a grade of recommendation (A-C, I). Superiority was determined for the clinical outcomes of pain, activity, Health Related Quality of Life (HRQL), readmission to hospital, revision surgery and general complications. RESULTS: There is fair evidence (GOR B) that supports both TAA and AA for the surgical treatment of ESAA. However, TAA trended to be superior for pain relief (GOR B), activity (GOR B), health related quality of life (GOR B) and readmission rate (GOR B) while AA trended to be superior for revision rates (GOR B). Conflicting evidence was presented for general complications (GOR C) CONCLUSION: Due to the lack of level I papers and the findings from the papers reviewed not being consistent, no definitive conclusion on which procedure is better can be made. However, there is enough evidence to provide a basis for which procedure is more effective in each of the outcomes reviewed. This should be considered when deciding on which procedure is best suited for a patient on a case-by-case basis. To allow for a stronger recommendation, further studies-ideally, high-quality level I randomized control trials directly comparing Ankle Arthrodesis and Total Ankle Arthroplasty are needed. LEVEL OF EVIDENCE: Level III, systematic review.

Surgical interventions of Freiberg's disease: A systematic review.

BACKGROUND: Freiberg's disease is an osteonecrosis of the metatarsal head bone. Numerous surgical interventions can be provided; however, the literature is limited in systematic reviews discussing the various options. The study aimed to systematically review the quantity and quality of literatures exploring the surgical interventions. METHODS: Fifty articles were found to be relevant for assessing the efficacy of common surgical interventions. The articles were assigned a level of evidence (I-V) to assess their quality. Next, the studies were reviewed to provide a grade of recommendation (A-C, I). RESULTS: Two studies were found at level III that explored osteotomy and autologous transplantation; the other studies were level IV-V. There is poor evidence (grade C) in supporting of joint sparing and joint sacrificing for Freiberg's disease. CONCLUSION: Poor evidence exists to support the surgical interventions for Freiberg's disease, higher quality trials are needed to support the increasing application of these surgical techniques. LEVEL OF EVIDENCE: Level IV, Systematic review.

Outcomes of Total Ankle Replacement, Arthroscopic Ankle Arthrodesis, and Open Ankle Arthrodesis for Isolated Non-Deformed End-Stage Ankle Arthritis.

BACKGROUND: End-stage ankle arthritis is a disabling condition that has a similar effect on morbidity, pain, and loss of function to hip arthritis. We compared clinical outcomes of total ankle replacement (TAR) involving the HINTEGRA prosthesis (Integra LifeSciences), arthroscopic ankle arthrodesis (AAA), and open ankle arthrodesis (OAA) in patients with isolated, non-deformed end-stage ankle arthritis. METHODS: Patients ≥18 years old who underwent TAR, AAA, or OAA from 2002 to 2012 with a minimum follow-up of 2 years were retrospectively identified from the Canadian Orthopaedic Foot and Ankle Society (COFAS) Prospective Ankle Reconstruction Database. All patients had symptomatic COFAS Type-1 end-stage ankle arthritis without intra-articular or extra-articular deformity or surrounding joint arthritis. Clinical outcomes included the Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36). Revision was defined as removal of 1 or both metal ankle prosthesis components for TAR and as reoperation for malposition, malunion, or nonunion for AAA and OAA. RESULTS: Analysis included 238 ankles (88 TAR, 50 AAA, and 100 OAA) in 229 patients with a mean follow-up of 43.3 ± 18.5 months. The TAR group had more female patients (55%; p = 0.0318) and a higher mean age (p = 0.0005). Preoperative AOS pain, disability, and total scores were similar for all groups. SF-36 physical and mental component summary scores were similar across groups, both preoperatively and postoperatively. Improvement in AOS total score was significantly larger for TAR (34.4 ± 22.6) and AAA (38.3 ± 23.6) compared with OAA (25.8 ± 25.5; p = 0.005). Improvement in AOS disability score was also significantly larger for TAR (36.7 ± 24.3) and AAA (40.5 ± 26.4) compared with OAA (26.0 ± 26.2; p = 0.0013). However, the greater improvements did not meet the minimal clinically important difference. The TAR group underwent more reoperations than AAA and OAA groups (p < 0.0001). Revision rates were similar for all 3 groups (p = 0.262). CONCLUSIONS: AAA and OAA resulted in comparable clinical outcomes to TAR in patients with non-deformed, COFAS Type-1 end-stage ankle arthritis. The rate of component revision in patients who underwent TAR was similar to the rate of revision for patients who underwent AAA or OAA; however, TAR patients underwent a greater number of additional procedures. Overall, AAA and TAR involving the HINTEGRA prosthesis were not significantly different surgical options in terms of short-term outcomes; patients should be counseled regarding higher reoperation rates for TAR. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Arthroscopic anterior talofibular ligament repair for lateral instability of the ankle.

UNLABELLED: Although several arthroscopic procedures for lateral ligament instability of the ankle have been reported recently, it is difficult to augment the reconstruction by arthroscopically tightening the inferior extensor retinaculum. There is also concern that when using the inferior extensor retinaculum, this is not strictly an anatomical repair since its calcaneal attachment is different to that of the calcaneofibular ligament. If a ligament repair is completed firmly, it is unnecessary to add argumentation with inferior extensor retinaculum. The authors describe a simplified technique, repair of the lateral ligament alone using a lasso-loop stitch, which avoids additionally tighten the inferior extensor retinaculum. In this paper, it is described an arthroscopic anterior talofibular ligament repair using lasso-loop stitch alone for lateral instability of the ankle that is likely safe for patients and minimal invasive. LEVEL OF EVIDENCE: Therapeutic study, Level V.

Gastrocnemius recession for foot and ankle conditions in adults: Evidence-based recommendations.

BACKGROUND: Gastrocnemius recession is a surgical technique commonly performed on individuals who suffer from symptoms related to the restricted ankle dorsiflexion that results when tight superficial posterior compartment musculature causes an equinus contracture. Numerous variations for muscle-tendon unit release along the length of the calf have been described for this procedure over the past century, although all techniques share at least partial or complete release of the gastrocnemius muscle given its role as the primary plantarflexor of the ankle. There exists strong evidence to support the use of this procedure in pediatric patients suffering from cerebral palsy, and increasingly enthusiastic support-but less science-behind its application in treating adult foot and ankle pathologies perceived to be associated with gastrocnemius tightness. The purpose of this study, therefore, was to evaluate currently available evidence for using gastrocnemius recession in three adult populations for whom it is now commonly employed: Achilles tendinopathy, midfoot-forefoot overload syndrome, and diabetic foot ulcers. METHODS: A systematic review of the literature was performed on December 21, 2013 using the PubMed, Scopus, and Cochrane databases along with the search term "(gastrocnemius OR gastrocsoleus) AND (recession OR release OR lengthening)." This search generated 1141 results; 12 articles found in the references of these papers were also screened for inclusion. In total, 18 articles met our inclusion criteria. These articles were reviewed and assigned a classification (I-V) of Level of Evidence, according to the criteria recommended by the Journal of Bone & Joint Surgery. Based on these classifications, a Grade of Recommendation was assigned for each of the indications of interest. RESULTS: Grade B evidence-based literature ("fair") exists to support the use of gastrocnemius recession for the treatment of isolated foot pain due to midfoot/forefoot overload syndrome in adults. There are some data in support of utilizing gastrocnemius recession to treat midfoot or forefoot ulcers and non-insertional Achilles tendinopathy in adults, but to date this evidence remains Grade Cf. Insufficient evidence (Grade I) is currently available to make any recommendation either for or against this procedure for the treatment of insertional Achilles tendinopathy. CONCLUSION: Scientific literature continues to grow in support of using isolated gastrocnemius recession as an effective treatment strategy for a variety of lower limb pathologies, although it remains clear that higher evidence levels and more carefully controlled investigations will be necessary to more convincingly define the true efficacy and ideal applications of gastrocnemius recession in the adult population. LEVEL OF EVIDENCE: Level IV systematic review.

Foot and ankle tendoscopy: evidence-based recommendations.

PURPOSE: The purpose of this study was to provide a comprehensive review of the current literature on tendoscopy of the foot and ankle and assign an evidence-based grade of recommendation for or against intervention. METHODS: A comprehensive review of the literature was performed on May 26, 2013, using the PubMed, Cochrane, and Scopus databases. Studies focusing on the use of foot and ankle tendoscopy were isolated, and these articles were then reviewed and assigned a Level of Evidence (I through V). The literature was then analyzed, and a grade of recommendation was assigned for tendoscopy of the tendons of the foot and ankle on which the procedure is generally performed. RESULTS: There is weak evidence (grade Cf) to support the use of tendoscopy on the Achilles, flexor hallucis longus, and peroneal tendons. Insufficient evidence (grade I) exists to assign a grade of recommendation for tendoscopy of the tibialis posterior, tibialis anterior, flexor digitorum longus, extensor hallucis longus, and extensor digitorum longus. CONCLUSIONS: A comprehensive review of the literature on foot and ankle tendoscopy has shown predominantly Level IV and V studies, with just 1 Level II study. On the basis of the current literature available, there is poor evidence (grade Cf) in support of Achilles, flexor hallucis longus, and peroneal tendoscopy for the common indications. There is insufficient evidence to make a recommendation (grade I) for or against tendoscopy of the tibialis posterior, tibialis anterior, flexor digitorum longus, extensor hallucis longus, and extensor digitorum longus. Although current literature suggests that tendoscopy is a safe and effective procedure, original scientific articles of higher levels of evidence are needed before a stronger recommendation can be assigned. LEVEL OF EVIDENCE: Level IV, systematic review of Level II, IV, and V studies.

Evidence-based analysis of the efficacy for operative treatment of hallux rigidus.

BACKGROUND: The aim of this article is to provide an evidence-based literature review and assessment of the quality of literature regarding operative interventions for hallux rigidus. METHODS: A comprehensive evidence-based literature review of the PubMed database was conducted on June 24, 2011, identifying 586 articles, of which 135 were relevant in assessing the efficacy of common operative interventions for hallux rigidus. The 135 studies were then assigned a level of evidence (I-V) to denote quality. They were then reviewed to provide a grade of recommendation (A-C, I) in support of or against the operative intervention in treatment of hallux rigidus. RESULTS: Based on the results of this evidence-based review, there is fair evidence (grade B) in support of arthrodesis for treatment of hallux rigidus. There is poor evidence (grade C) in support of cheilectomy, osteotomy, implant arthroplasty, resection arthroplasty, and interpositional arthroplasty for treatment of hallux rigidus. There is insufficient evidence (grade I) for cheilectomy with osteotomy for treatment of hallux rigidus. CONCLUSION: There are no consistent findings in comparative studies that are properly powered with validated and appropriate outcome measures to allow any definitive conclusions on which procedure is best. However, the grade B recommendation assigned to arthrodesis may make it the logical leading candidate for future high-quality randomized controlled trials. Clearly, further studies-ideally, high-quality Level I randomized controlled trials with validated outcome measures-are needed to allow stronger recommendations to be made. LEVEL OF EVIDENCE: Level III, systematic review.

Evidence-based indications for distraction ankle arthroplasty.

BACKGROUND: The purpose of this study was to review the literature to provide a comprehensive description of the Level of Evidence (LOE) available to support the operative technique of distraction ankle arthroplasty for the current generally accepted indications and make a grade of recommendation for each. METHODS: A comprehensive review of the literature was performed (November 2010 to January 2011) using the PubMed database. The abstracts from these searches were reviewed to isolate literature that described therapeutic studies investigating the results of distraction ankle arthroplasty. All articles were reviewed and assigned a classification (I-V) of Level of Evidence. An analysis of the literature reviewed was used to assign a Grade of Recommendation for each current generally accepted indication for distraction ankle arthroplasty. RESULTS: There is insufficient evidence based literature (Grade I) to support or refute the procedure for either: post-traumatic ankle arthritis, arthritis associated with ligamentous instability, primary degenerative joint disease, chondrolysis, deformity associated with arthritis, osteochondral defects and congenital ankle abnormalities. CONCLUSION: Inadequate evidence based literature exists to support or refute all currently accepted indications for distraction ankle arthroplasty and further high quality, scientific studies are needed upgrade to these recommendations.

Longitudinal migration and inducible displacement of the Mobility Total Ankle System.

BACKGROUND AND PURPOSE: RSA can be used for early detection of unstable implants. We assessed the micromotion of the Mobility Total Ankle System over 2 years, to evaluate the stability of the bone-implant interface using radiostereometric analysis measurements of longitudinal migration and inducible displacement. PATIENTS AND METHODS: 23 patients were implanted with the Mobility system. Median age was 62 (28-75) years and median BMI was 28.8 (26.0-34.5). Supine radiostereometric analysis examinations were done from postoperatively to the 2-year follow-up. Standing examinations were taken from the 3-month to the 2-year follow-up. Migrations and displacements were assessed using model-based RSA software (v. 3.2). RESULTS: The median maximum total point motion (MTPM) for the implants at 2 years was 1.19 (0.39-1.95) mm for the talar component and 0.90 (0.17-2.28) mm for the spherical tip of the tibial component. The general pattern for all patients was that the slope of the migration curves decreased over time. The main direction of motion for both components was that of subsidence. The median 2-year MTPM inducible displacement for the talar component was 0.49 (0.27-1.15) mm, and it was 0.07 (0.03-0.68) mm for the tibial component tip. INTERPRETATION: The implants subside into the bone over time and under load. This corresponds to the direction of primary loading during standing or walking. This statistically significant motion may become a clinically significant finding that would correspond with premature implant failure.

Responsiveness and validity of the SF-36, Ankle Osteoarthritis Scale, AOFAS Ankle Hindfoot Score, and Foot Function Index in end stage ankle arthritis.

BACKGROUND: We examined four commonly used scores, the SF-36, the Ankle Osteoarthritis Scale (AOS), the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Score, and the Foot Function Index (FFI) to determine their responsiveness and validity. METHODS: Patients with end stage ankle arthritis were recruited into a prospective multicenter cohort study and baseline and one year outcome scores were compared. The Standardized Response Mean and Effect Size for the AOS, AOFAS, and FFI were calculated and the three region- or disease-specific scores were compared with the SF-36 to determine their criterion validity. RESULTS: All four scores showed acceptable responsiveness, and when using the validated SF-36 as the standard the three region or disease specific scores all showed similar criterion validity. CONCLUSION: All four scores are responsive and can be considered for use in this population. The objective component of the AOFAS Ankle Hindfoot Score may make it harder to perform than the other three scores which have subjective components only, and as yet its objective component has not been shown to demonstrate reliability. We recommend use of a purely subjective score such as the Ankle Osteoarthritis Scale or Foot Function Index as the region- or disease-specific score of choice in this population. As the SF-36 shows acceptable responsiveness, using it alone could also be considered.

Evidence-based indications for elbow arthroscopy.

PURPOSE: The purpose was to review the literature on the outcomes of elbow arthroscopy and to make evidence-based recommendations for or against elbow arthroscopy for the treatment of various conditions. Our hypothesis was that the evidence would support the use of elbow arthroscopy in the management of common elbow conditions. METHODS: A literature search was performed by use of the PubMed database in October 2010. All therapeutic studies investigating the results of treatment with elbow arthroscopy were analyzed for outcomes and complications. The literature specific to common elbow arthroscopy indications was summarized and was assigned a grade of recommendation based on the available evidence. RESULTS: There is fair-quality evidence for elbow arthroscopy in the treatment of rheumatoid arthritis of the elbow and lateral epicondylitis (grade B recommendation). There is poor-quality evidence for, rather than against, the arthroscopic treatment of degenerative arthritis, osteochondritis dissecans, radial head resection, loose bodies, post-traumatic arthrofibrosis, posteromedial impingement, excision of a plica, and fractures of the capitellum, coronoid process, and radial head (grade C(f) recommendation). There is insufficient evidence to give a recommendation for or against the arthroscopic treatment of posterolateral rotatory instability and septic arthritis (grade I recommendation). CONCLUSIONS: The available evidence supports the use of elbow arthroscopy in the management of the majority of conditions where it is currently used. The quality of the evidence, however, is generally fair to poor. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.

The postoperative COFAS end-stage ankle arthritis classification system: interobserver and intraobserver reliability.

End-stage ankle arthritis is operatively treated with numerous designs of total ankle replacement and different techniques for ankle fusion. For superior comparison of these procedures, outcome research requires a classification system to stratify patients appropriately. A postoperative 4-type classification system was designed by 6 fellowship-trained foot and ankle surgeons. Four surgeons reviewed blinded patient profiles and radiographs on 2 occasions to determine the interobserver and intraobserver reliability of the classification. Excellent interobserver reliability (κ = .89) and intraobserver reproducibility (κ = .87) were demonstrated for the postoperative classification system. In conclusion, the postoperative Canadian Orthopaedic Foot and Ankle Society (COFAS) end-stage ankle arthritis classification system appears to be a valid tool to evaluate the outcome of patients operated for end-stage ankle arthritis.

Varus hindfoot deformity after talar fracture.

Posttraumatic malalignment after talar neck fractures invariably leads to painful functional impairment. Anatomic reduction and definitive, stable osteosynthesis at the primary surgical intervention is preventative. Secondary anatomic reconstruction with joint preservation should be considered in the absence of arthrosis in the peritalar articulations. Reorientating arthrodeses should be entertained where deformity has resulted in joint incongruity and, ultimately, posttraumatic arthritis. TAA may have a role as a motion-conserving procedure in combination with adjacent subtalar and midtarsal fusions.

Validation and precision of model-based radiostereometric analysis (MBRSA) for total ankle arthroplasty.

BACKGROUND: The goal of this study was to design a RSA marker insertion protocol to evaluate the stability of the bone-implant interface of a TAA prosthesis, and to validate that this marker insertion protocol can be combined with MBRSA technology to provide clinically adequate precision in assessing the micromotion of the TAA prosthesis. METHODS: The Mobility™ Total Ankle System was used in this study. A marker placement protocol was developed with a Phantom Protocol. The Improved Marker Placement Protocol was used in 20 patients. Postoperative RSA double exams were taken. Condition Numbers (CN) were used to assess the marker distribution. The system precision was defined as the standard deviation of the double exams (MTE, MRE). MBRSA software was used to evaluate the double exams. RESULTS: The RSA marker insertion technique for the 20 {\it in vivo} cases provided satisfactory results. CNs in all subjects but one were below 50 mm(-1) and implied a desirable marker configuration. The tibial sphere MTE was 0.07 mm and the talar was 0.09 mm. The talar MRE was 0.51 degrees. CONCLUSION: The system precision for these {\it in vivo} TAA implants was within the normal range identified by RSA studies, and comparable to the existing TAA RSA studies. This study demonstrated a reliable RSA marker insertion technique in both the tibia and talus. The study confirms that the insertion and MBRSA technique allows the typical high precision demonstrated in other RSA studies (standard deviation less than or equal to 0.25 mm or 0.6 degrees). CLINICAL RELEVANCE: This method may allow more accurate assessment of prosthetic subsidence clinically.

The evidence for hip arthroscopy: grading the current indications.

PURPOSE: The purpose of this systematic review is to provide a comprehensive analysis of the Level of Evidence and the Grade of Recommendation for hip arthroscopy. METHODS: A literature review was performed (in June 2010) using the PubMed and Cochrane databases. Studies that focused on the efficacy of hip arthroscopy for all therapeutic indications were reviewed to determine their Level of Evidence. The studies were grouped based on indication, and the literature supporting each indication was analyzed and assigned a Grade of Recommendation. A subscale proposed by us was used to further describe the evidence base for indications receiving a Grade of Recommendation indicating poor-quality evidence. RESULTS: Fair evidence (grade B) exists to support the surgical technique of hip arthroscopy for the treatment of femoroacetabular impingement. Poor-quality evidence (grade C(f)) exists to support a recommendation for the use of hip arthroscopy in the treatment of acetabular labral tears, extra-articular lesions, septic arthritis, and loose bodies. There is poor-quality conflicting evidence (C(c)) regarding the use of hip arthroscopy for the treatment of mild to moderate osteoarthritis of the hip. CONCLUSIONS: Although fair evidence (grade B) exists to support the use of hip arthroscopy for the treatment of femoroacetabular impingement, a majority of recognized indications for this surgical technique currently lack adequate evidence-based support in the literature (grade C or grade I). Higher-quality trials (Level I and Level II) are needed to provide support for the increasing application of this surgical technique. We also applied a new subscale to the grades of recommendation for summaries or reviews of orthopaedic surgical studies proposed by Wright et al. to provide a description of the direction in which outcomes are trending in Level IV studies. LEVEL OF EVIDENCE: Level IV, systematic review.

Inter- and intraobserver reliability of the COFAS end-stage ankle arthritis classification system.

BACKGROUND: End-stage ankle arthritis should have an appropriate classification to assist surgeons in the management of end-stage ankle arthritis. Outcomes research also requires a classification system to stratify patients appropriately. MATERIALS AND METHODS: Six fellowship trained foot and ankle surgeons met on two occasions to derive a classification system for end-stage ankle arthritis. A four-part classification system was designed. Four surgeons reviewed blinded patient profiles and radiographs on two occasions to determine the inter- and intraobserver reliability. RESULTS: Good interobserver reliability (kappa = 0.62) and intraobserver reproducibility (kappa = 0.72) was demonstrated for the classification system. CONCLUSION: The COFAS classification system appears to be a valid tool for the management and research of end-stage ankle arthritis.

Evidence-based indications for ankle arthroscopy.

PURPOSE: The purpose of this study was to review the literature to provide a comprehensive description of the Level of Evidence available to support the surgical technique of ankle arthroscopy for the current generally accepted indications and assign a grade of recommendation for each of them. METHODS: A comprehensive review of the literature was performed (in August 2008) by use of the PubMed database. The abstracts from these searches were reviewed to isolate literature that described therapeutic studies investigating the results of different ankle arthroscopic treatment techniques. All articles were reviewed and assigned a classification (I-IV) of Level of Evidence. An analysis of the literature reviewed was used to assign a grade of recommendation for each current generally accepted indication for ankle arthroscopy. RESULTS: There exists fair evidence-based literature (grade B) to support a recommendation for the use of ankle arthroscopy for the treatment of ankle impingement and osteochondral lesions and for ankle arthrodesis. Ankle arthroscopy for ankle instability, septic arthritis, arthrofibrosis, and removal of loose bodies is supported with only poor-quality evidence (grade C). Treatment of ankle arthritis, excluding isolated bony impingement, is not effective and therefore this indication is not recommended (grade C against). Finally, there is insufficient evidence-based literature to support or refute the benefit of arthroscopy for the management of synovitis and fractures (grade I). CONCLUSIONS: There exists adequate evidence-based literature to support the surgical technique of ankle arthroscopy for most current generally accepted indications; however, further studies in this area are needed. LEVEL OF EVIDENCE: Level IV, systematic review.

Evidence-based classification of complications in total ankle arthroplasty.

BACKGROUND: Total ankle arthroplasty (TAA) has become a viable treatment for end-stage ankle arthrosis. Current literature on survival rates and complications of TAA consist of mostly retrospective Level IV papers that do not provide a system for classifying complications. The aim of the current review is to provide a summary of TAA implant survival and complication rates from current literature on outcomes of second or third generation ankle prostheses and subsequently propose a classification system. METHODS: A literature review was used to identify articles reporting complications and failures of TAA ankle prostheses. Inclusion criteria included studies with at least 25 cases and a minimum of 24 months followup. RESULTS: Twenty studies met the inclusion criteria. The percentage of failed TAA reported for the short- and intermediate-term followup in this review ranged from 1.3 to 32.3 % with an overall mean of 12.4 % failure at 64 months. Nine main complications of TAA were identified. CONCLUSION: Deep infection, aseptic loosening and implant failure should be considered ;;high-grade'' complications since they will result in failure greater than 50% of the time. Technical error, subsidence and postoperative bone fracture should be considered "medium-grade'', while intra-op bone fractures and wound healing problems should be considered "low-grade''. We believe this review provides the groundwork for uniform complication reporting in TAA and allows the development of a classification system that will provide prognostic information that may serve to guide postoperative care of patients receiving TAA.

Histological analysis of achilles tendons in an overuse rat model.

The purpose of this study was to design an animal model that induces histological changes in Achilles tendons consistent with those cited in the literature for human Achilles tendon disease. Sprague-Dawley rats were subjected to 10 degrees uphill treadmill running on a custom-designed rodent treadmill and at a speed of 17 meters per minute for 1 h, five times per week, over a 12-week treatment period. Subsequent histological analysis revealed alterations in the rat Achilles tendon that were generally consistent with those described in the literature for diseased human tendon tissues. These features include: decreased collagen fiber organization, more intense collagen staining, and increased cell nuclei numbers. Interestingly, though, immunohistochemical cell typing suggests that the observed increased cellularity does not include a significant inflammatory component but is secondary to increased numbers of endothelial cells (i.e., vascularization) and fibroblasts. These histological features likely represent a biological repair/remodeling response resulting from overuse running.