Comparative Studies of Bone Graft and Orthobiologics for Foot Ankle Arthrodesis: A Critical Review.

Graft materials available to supplement hindfoot and ankle arthrodesis procedures include autologous (autograft) or allogeneic bone graft (allograft) but also bone graft substitutes such as demineralized bone matrix, calcium sulfate, calcium phosphate, and tricalcium phosphate/hydroxyapatite. In addition, biologic agents, such as recombinant human bone morphogenetic protein-2 or recombinant human platelet derived growth factor-BB (rhPDGF-BB), and preparations, including platelet-rich plasma or concentrated bone marrow aspirate, have been used to facilitate bone healing in ankle or hindfoot arthrodesis. The purpose of this review was to summarize the available clinical evidence surrounding the utilization and efficacy of the above materials and biological agents in ankle or hindfoot arthrodesis procedures, with emphasis on the quality of the existing evidence to facilitate clinical decision making.

Evidence Guiding Commercial Payer Coverage Criteria for Total Ankle Arthroplasty.

Background: Total ankle arthroplasty (TAA), first developed as an alternative to ankle arthrodesis, has become an increasingly popular management option for end-stage ankle arthritis. Prior studies have shown commercial insurance payers base their coverage criteria on limited and low level of evidence research. This study aims to quantify and describe the evidence insurance companies use to support TAA coverage policies. Methods: The top 11 national commercial health insurance payers for TAA were identified. A google search was performed to identify payer coverage policies. Policy documents were examined and cited references were classified by type of reference as well as reviewed for level of evidence (LOE). Specific coverage criteria for each individual payer were then extracted. Criteria were compared to assess for similarities among commercial payers. Finally, all references cited by each payer were examined to determine whether they mentioned the specific payer criteria. Results: Six of the 11 payers had accessible coverage policies. The majority of cited references were primary journal articles (145, 60.9%) and the majority of references cited (179, 75.2%) were level III or level IV evidence. We found significant homogeneity in coverage criteria among payers. In addition, cited sources inconsistently mentioned specific payer coverage criteria. Conclusion: This study demonstrates that commercial insurance payers rely on the relatively low level of currently available scientific evidence when formulating coverage policies for TAA use and adopt criteria that have not been thoroughly analyzed in the literature. More high level of evidence research is needed to help clinicians and insurance companies further refine indications for TAA so that patients who might benefit from the procedure are adequately covered. Level of Evidence: Level IV, review.

Elite Athletes Successfully Return to the Preinjury Level of Sport Following Ankle Syndesmosis Injuries: A Systematic Review and Meta-Analysis.

OBJECTIVE: To comprehensively review and report the outcomes of ankle syndesmotic injury management in elite athletes. DATA SOURCES: Three databases were searched for articles reporting the rate of return to sport following treatment of ankle syndesmotic injuries in elite athletes (collegiate or professional level). Ten articles and 440 athletes were included. Articles reporting the rate of return to sport following high ankle sprain injury in elite athletes. Data collected included demographics, type of treatment received, and return to sport (RTS) information. A random effects model was used. MAIN RESULTS: The estimated overall rate of RTS was 99% (95% CI, 95.5-99.9). The mean time to RTS was 38 ± 18 (range, 14-137) days. Of the 440 athletes, 269 (269/440%, 61%) were treated nonoperatively (nonoperative group); the rate of RTS was 99.6%, and the athletes returned at a mean time of 29 ± 14 (range, 13-45) days. A total of 171 athletes (171 of 440%, 39%) underwent surgical treatment (operative group). All (171 of 171%, 100%) athletes returned at a mean time of 50.3 ± 13 (range, 41-137) days. Almost all athletes who underwent surgery had suture button fixation (164 of 171 athletes, 96%), and the mean time to RTS was 7 weeks with 9.1% complication rate. CONCLUSIONS: Elite athletes with ankle syndesmosis injury return to sport at an extremely high rates, following operative or nonoperative treatment. Return to the preinjury level of competition should be expected at 4 weeks and 7 weeks in high-level athletes who undergo nonoperative and operative management, respectively. Suture button fixation was used by the majority of studies reporting surgical management of ankle syndesmosis injuries in athletes.

Return to Sport Following Operative Treatment of Displaced Medial Sesamoid Fractures in NCAA Division I Football Players.

Level of Evidence: Level V.

Suture Tape Augmentation in Lateral Ankle Ligament Surgery: Current Concepts Review.

Chronic lateral ankle instability (CLAI) is a condition that is characterized by persistent disability and recurrent ankle sprains while encompassing both functional and mechanical (laxity) instability. Failure of conservative treatment for CLAI often necessitates operative intervention to restore the stability of the ankle joint. The traditional or modified Broström techniques have been the gold standard operative approaches to address CLAI with satisfactory results; however, patients with generalized ligament laxity (GLL), prior unsuccessful repair, high body mass index, or high-demand athletes may experience suboptimal outcomes. Synthetic ligament constructs have been tested as an adjunct to orthopedic procedures to reinforce repaired or reconstructed ligaments or tendons with the hope of early mobilization, faster rehabilitation, and long-term prevention of instability. Suture tape augmentation is useful to address CLAI. Multiple operative techniques have been described. Because of the heterogeneity among the reported techniques and variability in postoperative rehabilitation protocols, it is difficult to evaluate whether the use of suture tape augmentation provides true clinical benefit in patients with CLAI. This review aims to provide a comprehensive outline of all the current techniques using suture tape augmentation for treatment of CLAI as well as present recent research aimed at guiding evidence-based protocols.

Learning curve assessment for total ankle replacement using the transfibular approach.

BACKGROUND: Total ankle arthroplasty is an increasingly effective option for the treatment of end-stage arthritis. One recent innovation utilizes a transfibular, lateral approach. Like any new system, there is likely a learning curve associated with its use. We analyzed a series of patients who received a total ankle arthroplasty via a transfibular approach to state if it is possible to identify and to evaluate effects of a learning curve in the use of this novel total ankle replacement system. METHODS: 76 consecutive patients meeting inclusion and exclusion criteria were retrospectively analyzed. All patients had a minimum of 24 months of follow-up. Intraoperative parameters, preoperative and postoperative subjective outcome scores, radiographic parameters, and complications were recorded and evaluated. RESULTS: There were significant learning curve effects on various surgical and postoperative parameters. Surgical time decreased with the curve stabilizing after the 16th patient. With regard to patient outcomes, a learning curve was identified for the VAS, AOFAS, and SF-12 MCS scores. The number of patients required to stabilize these curves were 21, 13, and 16, respectively. Alignment as measured by alpha and gamma angles also improved with experience, with the curves stabilizing at 18 and 15 patients, respectively. There was a larger number cases required for complication rates, with the curve stabilizing after the 39th patient. No significant learning curve was found for ankle ROM, SF-12 PCS, beta angle, tibio-talar ratio (TTR), or tibio-talar surface angle (TTS). CONCLUSIONS: This study demonstrates a significant learning curve with respect to operative time, patient outcomes, and radiographic parameters. Extrapolating this information, we urge surgeons to adequately familiarize themselves with any new implant through a training program in a high-volume center. LEVEL OF EVIDENCE: IV, case series.

Outcomes of flexor digitorum longus (FDL) tendon transfer in the treatment of Achilles tendon disorders.

BACKGROUND: In patients with chronic Achilles tendon disorders, Achilles tendon debridement can be supplemented with a tendon transfer, with the flexor hallucis longus tendon (FHL) transfer representing the most common used technique. Our study describes clinical and functional results of patients treated with flexor digitorum longus (FDL) tendon transfer in the treatment of patients with chronic Achilles tendon disorders. METHODS: Retrospective study of prospectively collected data of thirteen patients (15 feet) that underwent FDL tendon transfer as part of the treatment of chronic Achilles tendon disorders. Preoperative and postoperative assessment included visual analogue score (VAS) for pain, SF-36 survey and lower extremity functional scale (LEFS). The average follow-up was 26.4 (range, 14-56) months. Patients were also assessed for ability to perform single leg heel rise test, muscle power for plantar flexion of the lesser toes, surgical scar condition and associated complications. RESULTS: At final follow-up, we found significant postoperative improvement in VAS score (6.6 ±â€¯2.99 vs 1.06 ±â€¯1.43; p < .0001), SF-36 physical component summary (PCS) (28.20 ±â€¯10.71 vs 45.04 ±â€¯11.19; p < .0001) and LEFS (36.13 ±â€¯20.49 vs 58.73 ±â€¯18.19; p < .0001). Twelve patients (92%) could perform a single leg heel rise test in the operated extremity, although there was significant difference when comparing operated and uninvolved sides (4.86 ±â€¯3.36 cm vs 7.18 ±â€¯3.40 cm; p = .0002). One patient reported weakness for plantar flexion of the lesser toes, without balance or gait disturbances. Two patients (2 feet, 13.3%) had superficial infections and one patient (one foot, 6.6%) needed operative debridement for a deep infection. CONCLUSIONS: FDL tendon transfer represent an operative alternative in the treatment of chronic Achilles tendon disorders. Our study showed good clinical outcomes with low complications and donor site morbidity. LEVEL OF EVIDENCE: Observational study, case series - level IV.

Patient and Practice Trends in Total Ankle Replacement and Tibiotalar Arthrodesis in the United States From 2007 to 2013.

INTRODUCTION: Both total ankle replacement (TAR) and tibiotalar arthrodesis (TTA) are used in the surgical management of ankle arthritis. Over the past decade, TAR instrumentation, techniques, and implants have improved, making the procedure more reliable and reproducible, thus making TAR more common. METHODS: The Nationwide Inpatient Sample database from 2007 to 2013 was used to obtain data on patients elder than 50 years who underwent either TAR or TTA. Differences in temporal, demographic, and diagnosis trends between TAR and TTA were analyzed. RESULTS: Between 2007 and 2013, 15,060 patients underwent TAR and 35,096 underwent TTA. Patients undergoing TTA had significantly more comorbidities (2.17 versus 1.55; P < 0.001). The share of TAR performed increased significantly from 2007 (14%) to 2013 (45%) (P < 0.001). From 2007 to 2013, we found a 12-fold increase in the odds of having a TAR for patients with posttraumatic osteoarthritis (P < 0.001), a 4.9-fold increase for those with primary osteoarthritis, and a 3.1-fold increase for patients with rheumatoid arthritis (P < 0.001). CONCLUSIONS: Over the past decade, the frequency of TAR has increased, particularly in patients with posttraumatic arthritis and osteoarthritis. Surgeons still perform TAR in healthier patients compared with TTA; however, because surgeons become more experienced with the technique, patients are undergoing TAR at a markedly higher rate. LEVEL OF EVIDENCE: Level III: retrospective comparative study.

Fibular groove morphology and measurements on MRI: correlation with fibularis tendon abnormalities.

PURPOSE: Fibular (peroneal) groove morphology may influence fibularis tendon pathology, including tendinosis, tears, and luxation. The study goal was to evaluate the inter-reader agreement of morphologic characterization and measures of the fibular groove at two different levels on MRI and correlation with fibularis tendon pathology. MATERIALS AND METHODS: 47 ankle MRIs in patients without lateral ankle pain were reviewed by two musculoskeletal radiologists. Fibular groove morphology and various measurements were assessed at both the level of the tibial plafond and 1 cm proximal to the tip of the lateral malleolus. Fibularis tendon pathology and other variants were also recorded. Intraclass correlation (ICC) and kappa statistic (κ) were applied to assess inter-observer agreement. Receiver operating characteristic (ROC) and area under the curve (AUC) analysis were performed to determine correlation between fibular groove morphometry and fibularis (peroneus) brevis tendon tears. RESULTS: Between readers, there was fair-to-excellent agreement (ICC = 0.61-0.95) for performed fibular groove measurements and moderate-to-very good agreement for identification and description of fibular groove and fibularis tendon morphology and pathology and normal variants in this region (κ = 0.46-1), with the exception of fibular groove morphology at 1 cm proximal to the lateral malleolar tip (κ = 0.34). Individually, no measurement or description of pathology could discriminate between patients with or without fibularis brevis tendon tears except fibularis brevis tendinosis (AUC = 0.87 for reader 1). CONCLUSION: There is overall moderate-to-excellent inter-reader agreement for various measurements and descriptors of fibular groove and fibularis tendon morphometry and pathology, including novel measurements introduced in this study.

Clinical and Radiological Outcomes of Transfibular Total Ankle Arthroplasty.

BACKGROUND:: Ankle arthritis is a highly limiting pathology that causes pain and functional limitation with subsequent deterioration of quality of life. With recent advances in surgical instrumentation and techniques, prosthetic replacement of the ankle has proven to be a valid alternative to arthrodesis with comparable outcomes. The purpose of this study was to evaluate clinical and radiological findings in a transfibular total ankle replacement with follow-up of at least 2 years. METHODS:: This prospective study included 89 patients who underwent transfibular total ankle arthroplasty from May 2013 to February 2016. The mean age was 53.2 ± 13.5 years. All patients were followed for at least 24 months postoperatively with an average follow-up of 42.0 ± 23.5 months. Patients were assessed clinically and radiographically preoperatively and at 6, 12, and 24 months postoperatively. RESULTS:: At 24 months postoperatively, patients demonstrated statistically significant improvement in the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score from 33.8 ± 14.3 to 88.5 ± 6.6 ( P < .001), visual analog scale (VAS) from 80.5 ± 17.0 to 14.1 ± 9.2 ( P < .001), and Short Form-12 Physical and Mental Composite Scores from 29.9 ± 6.7 and 43.3 ± 8.6 to 47.0 ± 7.6 and 53.3 ± 8.1, respectively ( P < .001). In addition, ankle dorsiflexion and plantarflexion improved from 6.2 ± 5.5 and 9.6 ± 5.8 degrees to 24.2 ± 7.9 and 18.1 ± 7.6 degrees, respectively ( P < .001). Radiographically, patients demonstrated maintained neutral alignment of the ankle at 24 months. No patient demonstrated any radiographic evidence of tibial or talar lucency at final follow-up. Seven patients underwent reoperation for removal of symptomatic hardware (6 fibular plates, 1 syndesmotic screw); 2 patients experienced delayed wound healing. The first one was treated with plate removal and flap coverage. The second one required fibular plate removal. One patient developed a postoperative prosthetic infection requiring operative debridement, removal of implants, and placement of an antibiotic spacer. CONCLUSION:: This study found that transfibular total ankle replacement was a safe and effective option for patients with ankle arthritis resulting in improvements in patient-reported outcomes, range of motion, and radiographic parameters. However, further studies are required to determine the mid- and long-term performance of these implants. LEVEL OF EVIDENCE:: Level IV, case series.

Histological and Gross Evaluation through Second-Look Arthroscopy of Osteochondral Lesions of the Talus after Failed Treatment with Particulated Juvenile Cartilage: A Case Series.

INTRODUCTION: The treatment of osteochondral lesions of the talus (OLTs) recalcitrant to non-surgical interventions is challenging. Particulated juvenile cartilage allograft transplantation (PJCAT) has become a viable treatment option, obviating the need for an osteotomy or second-stage surgery and eliminating risk of donor site morbidity. Short-term outcomes have been promising, but failures associated with PJCAT have not been well described. CASE REPORT: Four patients with OLTs who had continued symptoms after PJCAT underwent a second-look arthroscopic evaluation. The quality of cartilage repair was evaluated using the international cartilage repair society (ICRS) score. Biopsy of the repair was taken for histological analysis. Two patients demonstrated a lack of integration of the allograft into the surrounding cartilage, and two had failures associated with impingement. Three patients' repairs were consistent with a Grade III ICRS score and one with a Grade II score. Histological examination demonstrated fibrotic repair tissue (Type 1 collagen) with depleted proteoglycans and Type II collagen. CONCLUSION: There were no obvious patients or surgical factors associated with poor outcomes. Integration of PJCAT with surrounding cartilage appears to be affected by biological and mechanical factors. Further, understanding of factors influencing PJCAT integration will help develop more specific indications for use.

☆Diagnostic and therapeutic injections of the foot and ankle-An overview.

Foot and ankle injections are useful diagnostic and therapeutic tools, particularly when the pain etiology is uncertain. A variety of foot and ankle injuries and pathologies, including degenerative joint disease, plantar fasciitis and different tendinopathies are amenable to injections. Understanding the foot and ankle anatomical landmarks, a thorough physical exam and knowledge of the different injection techniques is key for a successful approach to different pathologies. The objective of this study is to review the use of foot and ankle injections in the orthopaedic literature, present the readers with the senior author's experience and provide a comprehensive clinical guideline to the most common foot and ankle diagnostic and therapeutic injections.

Bone-block arthrodesis procedure in failures of first metatarsophalangeal joint replacement.

BACKGROUND: The treatment for the failure of a first metatarsophalangeal joint (MTP1) prosthesis can be complex. There is no consensus regarding the ideal treatment. One of the main issues is the available bone stock after prosthesis removal. The aim of the study was to report the clinical and radiographic results for MTP1 arthrodesis with autologous calcaneus bone graft (bone-block fusion) as a revision procedure of a previous MTP1 implant failure. METHODS: This study included 12 patients diagnosed with failure of a MTP1 prosthesis. All patients were treated with MTP1 arthrodesis using ipsilateral calcaneal bone graft. Patients were evaluated with the Foot Ankle Disability Index (FADI), the visual analogue pain scale (VAS) and AOFAS Hallux Metatarsophalangeal Interphalangeal scoring system (AOFAS-HMI), weight-bearing radiograph of the foot, and a computed tomography scan. The 1-2 intermetatarsal angle, hallux valgus angle, and first ray length were measured before surgery and at final follow-up. RESULTS: Complications included 3 cases of arthrodesis nonunion, (1 symptomatic, 2 asymptomatic) with 2 of the 3 patients experiencing hardware failure and 1 superficial wound infection. The average FADI improved from 41.8 preoperatively to 84.6 at final follow-up (p<0.05); the average VAS improved from 8.5 preoperatively to 2 at final follow-up (p<0,05); the average AOFAS-HMI significantly improved from 50.7 preoperatively to 73.8 at final follow-up (p<0.05). The average length of the bone-block used was 14.3mm (range 11-19mm). The 1-2 intermetatarsal angle decreased from 9.5° preoperatively to 8.4° at final follow-up (p<0.05); hallux valgus angle improved from 19.7° preoperatively to 14.3° at final follow-up (p<0.05). CONCLUSIONS: The management of a failed first metatarsophalangeal joint prosthesis remains controversial. Bone-block arthrodesis using ipsilateral calcaneal autograft appears to be a viable option restoring the bone loss, and avoiding hallux shortening. Nonunion is the most frequent complication with 25% of patients affected, but only 1/3 of patients with nonunion were symptomatic and required revision.

Identifying the learning curve for total ankle replacement using a mobile bearing prosthesis.

BACKGROUND: Total ankle arthroplasty remains a technically demanding surgery highly influenced by the operator experience. However, no consensus exists regarding the ideal number of cases that need to be performed before a surgeon is considered proficient. The aim of this study was to identify the learning curve of a specific replacement system with regards to intraoperative and postoperative outcomes. METHODS: The first 31 patients undergoing total ankle arthroplasty were examined. No additional procedures were performed at the time of the TAA. Intraoperative characteristics, postoperative complications, as well as clinical and radiologic outcomes were assessed with 24-month follow-up. Learning curves, examining the relationship between surgeon experience and patient outcomes, were determined using the Moving Average Method. RESULTS: The operatory time, and the risk of intraoperative fractures decreased with increasing surgeon experience with the learning curve stabilizing after the 14th and 24th patient, respectively. Furthermore, there appeared to be a learning curve associated with most of the important clinical and radiological outcomes. The number of patients required to stabilize the learning curve for the VAS, ROM, and AOFAS was 11, 14 and 28, respectively. Radiographically, there appeared to be a learning curve of 22 patients required to stabilize the tibio-talar ratio. There was no learning curve associated with the SF-12 PCS and MCS as well as the α-, ß-, and γ-angle. CONCLUSION: This study demonstrates that a surgical learning curve does indeed exist when performing TAA. Most of the operative variables as well as clinical and radiological outcomes stabilize after a surgeon has performed 28 cases.

Post-Traumatic Periprosthetic Tibial and Fibular Fracture After Total Ankle Arthroplasty: A Case Report.

Periprosthetic fractures after total ankle arthroplasty are uncommon, with most cases occurring intraoperatively. We describe a post-traumatic periprosthetic fracture of the distal tibia and fibula after total ankle arthroplasty that was treated with minimally invasive plate osteosynthesis. It is important for orthopedic surgeons not only to recognize the risk factors for postoperative periprosthetic total ankle arthroplasty fractures, but also to be familiar with the treatment options available to maximize function and minimize complications. The design of the tibial prosthesis and surgical techniques required to prepare the ankle joint for implantation are important areas of future research to limit the risk of periprosthetic fractures.

Effect of Insurance on Rates of Total Ankle Arthroplasty Versus Arthrodesis for Tibiotalar Osteoarthritis.

BACKGROUND: Several studies have examined the effect of insurance on the management of various orthopedic conditions. The purpose of our study was to assess the effect of insurance and other demographic factors on the operative management of tibiotalar osteoarthritis. METHODS: The National Inpatient Sample (NIS) database was used to identify patients who underwent a total ankle arthroplasty (TAA) or tibiotalar arthrodesis (TTA) for tibiotalar osteoarthritis. Insurance status was identified for each patient, and the proportions of each insurance type were computed for each operative modality. A multivariate analysis was performed to account for confounding variables to isolate the effect of insurance type on operative treatment. RESULTS: From 2007 to 2012, a total of 10 010 patients (35.6%) were identified who underwent a total ankle replacement (TAR) procedure and 18 094 patients (64.4%%) who underwent TTA for tibiotalar osteoarthritis. Patients receiving a TAR were older (65.8 vs 64.2, P < .001), more likely to be female (54% vs 51%, P < .001), and had fewer comorbidities (4.2 vs 4.5, P < .001) than patients who underwent a TTA. After controlling for baseline differences, patients with Medicare (odds ratio [OR] 3.00, P < .001), and private insurance (OR 3.19, P < .001) were approximately 3 times more likely to undergo TAR than patients with Medicaid. CONCLUSIONS: Patients with tibiotalar osteoarthritis were more likely to receive a TAR procedure if they had Medicare or private insurance compared with patients who had Medicaid. Further research should be done to better understand the drivers of this phenomenon if equitable care is to be achieved. LEVEL OF EVIDENCE: Level II, prognostic study.

Mesenchymal Stem Cell-Bearing Sutures for Tendon Repair and Healing in the Foot and Ankle.

Improving the quality and strength of soft tissue repairs remains an important area of orthopedic research and innovation. The need for immobilization and early motion is an important balance essential for the successful treatment of tendon repair and reconstruction. Mesenchymal stem cell (MSC)-bearing sutures represent an emerging biological augmentation to traditional suture repair. Two previous large studies using stem cell sutures in rat Achilles tendon models have demonstrated early increased biomechanical strength and significantly increased ultimate failure strength. The MSCs seem to remain locally at the repair site and enhance the histologic repair quality of the tendon collagen.

Early Complications and Secondary Procedures in Transfibular Total Ankle Replacement.

BACKGROUND: A new transfibular total ankle arthroplasty (TAA) system has not been assessed for potential early complications. METHODS: We retrospectively assessed prospectively collected data on the initial cohort of patients undergoing TAA with this implant. We evaluated visual analog scale (VAS) pain and function, range of motion, and early radiographic outcomes. RESULTS: Twenty consecutive TAAs (19 patients) were treated with the implant from January 2013 through June 2014. Average patient age was 63.7 (range, 41-80) years, with an average follow-up of 18 (range, 12-27) months. No fibular nonunion or implant failure was found at 12 months postoperatively. One patient had asymptomatic mild tibial lucency. Four of 20 TAAs underwent additional surgery for anterior impingement (1 ankle), deep infection and symptomatic fibular hardware (1 ankle), and symptomatic fibular hardware (2 ankles). CONCLUSION: Of 20 ankles treated with a new transfibular arthroplasty system, no fibular nonunion, delayed union, or implant failure was noted at 12 months postoperatively. Two complications were resolved with secondary treatment, and 2 other ankles underwent secondary surgery for symptomatic fibular hardware with good outcome. The findings suggest that this total ankle system is safe and effective at short-term follow-up. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Early Weightbearing After Operatively Treated Ankle Fractures: A Biomechanical Analysis.

BACKGROUND: No consensus exists regarding the timing of weightbearing after surgical fixation of unstable traumatic ankle fractures. We evaluated fracture displacement and timing of displacement with simulated early weightbearing in a cadaveric model. METHODS: Twenty-four fresh-frozen lower extremities were assigned to Group 1, bimalleolar ankle fracture (n=6); Group 2, trimalleolar ankle fracture with unfixed small posterior malleolar fracture (n=9); or Group 3, trimalleolar ankle fracture with fixed large posterior malleolar fracture (n=9) and tested with axial compressive load at 3 Hz from 0 to 1000 N for 250 000 cycles to simulate 5 weeks of full weightbearing. Displacement was measured by differential variable reluctance transducer. RESULTS: The average motion at all fracture sites in all groups was significantly less than 1 mm (P < .05). Group 1 displacement of the lateral and medial malleolus fracture was 0.1±0.1 mm and 0.4±0.4 mm, respectively. Group 2 displacement of the lateral, medial, and posterior malleolar fracture was 0.6±0.4 mm, 0.5±0.4 mm, and 0.5±0.6 mm, respectively. Group 3 displacement of the lateral, medial, and posterior malleolar fracture was 0.1±0.1 mm, 0.5±0.7 mm, and 0.5±0.4 mm, respectively. The majority of displacement (64.0% to 92.3%) occurred in the first 50 000 cycles. There was no correlation between fracture displacement and bone mineral density. CONCLUSION: No significant fracture displacement, no hardware failure, and no new fractures occurred in a cadaveric model of early weightbearing in unstable ankle fracture after open reduction and internal fixation. CLINICAL RELEVANCE: This study supports further investigation of early weightbearing postoperative protocols after fixation of unstable ankle fractures.

Posterior Talar Shifting in Mobile-Bearing Total Ankle Replacement.

BACKGROUND: End-stage ankle osteoarthritis frequently involves multiplanar malalignment in both the coronal and the sagittal planes. Sagittal malalignment often includes anterior translation of the talus relative to the tibia. Restoration of the correct tibial and talar alignment is essential for the long-term survival of total ankle replacement. METHODS: This study includes 66 consecutive patients who underwent total ankle arthroplasty with the Hintegra prosthesis from May 2011 to April 2014. There were 28 females (42.4%) and 38 males (57.6%) with a mean age of about 57 years (25-82 years). Patients were clinically and radiologically assessed preoperatively and at 2, 6, and 12 months postoperatively. RESULTS: At 12 months postoperatively, there was a statistically significant increase in American Orthopaedic Foot & Ankle Society scores from 31.9 to 72.3. Range of motion significantly increased from 9.5 to 25.4 degrees. In addition, there was a statistically significant decrease in visual analog scale (VAS) pain score from 8.9 to 2.2. Furthermore, there was a significant increase in the Tibio-Talar ratio from 2 to 6 months postoperatively (34.6%-37.2%). CONCLUSIONS: This study demonstrated significant improvements in clinical and radiologic outcomes after Hintegra total ankle arthroplasty. Significant movement of the talus occurs within the first 6 months postoperatively. This may be the result of rebalancing of muscle and ligament forces after surgery. LEVEL OF EVIDENCE: Level IV, case series.