Comparison of Direct Repair Versus Anatomic Graft Reconstruction of the Anterior Talofibular Ligament: A Biomechanical Cadaveric Study.

The goal of our study is to compare the stability of the anatomic reconstruction of the anterior talofibular ligament (ATFL) with direct repair of the ATFL, in a cadaver model. We performed the following techniques in 18 cadaveric ankles: the intact ATFL was cut, after which a direct repair using 2 anchors was performed. The repair was sectioned, and anatomic reconstruction was then performed with a tendon autograft. We measured angular displacement in 3 anatomic planes (axial, coronal, sagittal) for each situation in response to the anterior drawer test (ADT), talar tilt test (TTT) and pivot test (PT), using a specifically constructed arthrometer. The sectioned ATFL was inferior to the intact ATFL in the axial plane with the ADT (p = .012), in the axial plane with the PT (p = .001) and in the axial and coronal planes with the TTT (p = .013 and p = .016, respectively). Direct anatomic repair was inferior to the intact ATFL in the axial plane upon the PT (p = .009). No differences could be found between anatomic graft reconstructions and the intact ATFL with any manoeuver, nor when comparing anatomic graft reconstruction and direct repair with 2 anchors. We were able to conclude that anatomic graft reconstruction of the ATFL reproduces angular stability of the native ligament in a cadaver model. While we could not detect if anatomic graft reconstruction was superior to direct repair, the latter proved to be less stable in the axial plane upon internal rotation (pivot test) versus the intact ATFL.

Reconstruction of the interosseous talocalcaneal ligament using allograft for subtalar joint stabilization is effective.

PURPOSE: The aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial planes. METHODS: Fifteen fresh frozen cadaveric legs were used, with transfixed tibiotalar joints to isolate motion to the subtalar joint. An arthrometer fixed to the lateral aspect of the calcaneus measured angular displacement in all three spatial planes on the inversion and eversion stress tests. Stress manoeuvres were tested with the intact joint, and then repeated after sequentially sectioning the inferior extensor retinaculum (IER), cervical ligament (CL), interosseous talocalcaneal ligament (ITCL), arthroscopic graft reconstruction of the ITCL, and sectioning of the calcaneo-fibular ligament (CFL). RESULTS: Sectioning the ITCL significantly increased angular displacement upon inversion and eversion in the coronal and sagittal planes. Reconstruction of the ITCL significantly improved angular stability against eversion in the axial and sagittal planes, and against inversion in the axial and coronal planes, at the zero time point after reconstruction. After sectioning the CFL, resistance to eversion decreased significantly in all three planes. CONCLUSION: Progressive injury of ligamentous stabilisers, particularly the ITCL, led to increasing angular displacement of the subtalar joint measured with the inversion and eversion stress tests, used in clinical practice. Reconstruction of the ITCL using tendon graft significantly stabilised the subtalar joint in the axial and sagittal planes against eversion and in the axial and coronal planes against inversion, immediately after surgery.

Isolated distal pisiform dislocation: Case Report.

Isolated pisiform dislocation is a rare lesion with few cases described in the literature. This type of lesion is typically observed in young males and can be easily overlooked at first assessment. Isolated proximal dislocation is more common due to the action of the flexor carpi ulnaris (FCU) muscle. We present the case of a 19-year-old male patient with isolated distal pisiform dislocation after wrist trauma. He underwent open reduction and internal fixation with Kirschner wires with excellent functional outcomes. Although there is no consensual therapeutic method, closed reduction is a first-line treatment for acute presentations. Pisiform open reduction or excision may be performed alternatively or after a failed closed reduction.

Isolated distal pisiform dislocation: Case Report / Luxação distal isolada do pisiforme: Relato de caso

Abstract Isolated pisiform dislocation is a rare lesion with few cases described in the literature. This type of lesion is typically observed in young males and can be easily overlooked at first assessment. Isolated proximal dislocation is more common due to the action of the flexor carpi ulnaris (FCU) muscle. We present the case of a 19-year-old male patient with isolated distal pisiform dislocation after wrist trauma. He underwent open reduction and internal fixation with Kirschner wires with excellent functional outcomes. Although there is no consensual therapeutic method, closed reduction is a first-line treatment for acute presentations. Pisiform open reduction or excision may be performed alternatively or after a failed closed reduction.

Resumo A luxação isolada do pisiforme é uma lesão rara com poucos casos descritos na literatura. Esse tipo de lesão é observado tipicamente em adultos jovens do sexo masculino e pode ser facilmente negligenciada numa primeira avaliação. A luxação proximal isolada é mais comum devido à ação do flexor ulnar do carpo (FUC). Apresentamos o caso de um paciente do sexo masculino, com 19 anos de idade, com luxação distal isolada do pisiforme após traumatismo do punho. O paciente foi submetido a uma redução aberta e fixação interna com fios de Kirschner com excelente resultado funcional. Apesar de não existir um método de tratamento consensual, a redução fechada perfila-se como tratamento de primeira linha na apresentação aguda. Em caso de insucesso ou como método alternativo pode-se optar pela redução aberta ou a excisão do pisiforme.

[Consecutive Ankle Sprain Classification and Injury Systematization (CASCaIS), A New Lateral Ankle Sprain Classification Based on the Pivot Test: A Prospective Cohort Study]. / Consecutive Ankle Sprain Classification and Injury Systematization (CASCaIS), Uma Nova Classificação de Entorse Lateral do Tornozelo Baseada no Teste de Pivot: Estudo Prospetivo de Coorte.

INTRODUCTION: The biggest challenge in the treatment of acute ankle sprain is the uncertainty of the prognosis. The traditional classifications have several interpretations and little correlation with prognosis. In this study we propose a new classification for acute ankle sprain only based on clinical criteria. MATERIAL AND METHODS: We prospectively evaluated all patients with an ankle sprain, aged between 18 and 45 years, admitted to a hospital during a 24 month period. The minimum follow-up period was 12 months. The sprains were classified, in the first few days (CASCaIS-Initial), according to autonomous gait capacity, inspection and palpation. After a few weeks (CASCaIS-Deferred), it was complemented with the mechanical evaluation of ligaments through the ankle pivot test. RESULTS: Among the 49 patients who completed the follow-up, none of those who had a pivot-negative test progressed to chronic ankle instability (CAI). Nine of the 33 patients (27%) with a positive pivot progressed to CAI (p = 0.022). The evaluation of CASCaIS-Deferred demonstrated an association with CAI (p = 0.018). CONCLUSION: This classification proved to be a simple, inexpensive, and reliable tool that clinicians can use to determine the prognosis of the sprain.

Introdução: O maior desafio no tratamento da entorse aguda do tornozelo é a indefinição do prognóstico. As classificações clássicas têm várias interpretações e pouca correlação com o prognóstico. Com este trabalho propomos uma nova classificação baseada apenas em critérios clínicos.Material e Métodos: Foram prospectivamente avaliados doentes entre os 18 e os 45 anos com entorse aguda do tornozelo, admitidos numa instituição durante 24 meses. O seguimento mínimo teve uma duração de 12 meses. Estes doentes foram classificados nos primeiros dias após a entorse (CASCaIS-Inicial) com base na valorização da capacidade de marcha autónoma, inspeção do quadro inflamatório e palpação. Passadas algumas semanas (CASCaIS-Diferida) complementou-se com a avaliação ligamentar pelo teste de pivot do tornozelo.Resultados: Dos 49 doentes que completaram o seguimento, nenhum dos que tinha um teste pivot-negativo evoluiu para instabilidade crónica do tornozelo (ICT). Nove dos 33 doentes (27%) com um pivot-positivo evoluíram para ICT (p = 0,022). A avaliação da CASCaIS-Diferida demonstrou uma associação com a ICT (p = 0,018).Conclusão: Esta classificação demonstrou ser uma ferramenta simples, não dispendiosa e fiável que os clínicos poderão usar para determinar o prognóstico da entorse.

Influence of the PFNA screw position on the risk of cut-out in an unstable intertrochanteric fracture: a computational analysis.

The position of the lag screw in the femoral head is a key factor to cut-out, the most reported complication in the internal fixation of intertrochanteric fractures. Considering that the best position for the lag screw remains controversial, the aim of this study was to evaluate the influence of different lag screw positions on the risk of cut-out of an unstable intertrochanteric fracture fixed with a Proximal Femoral Nail Anti-Rotation (PFNA) implant. The relationship between cut-out and the tip-apex distance (TAD) or the calcar referenced tip-apex distance (CalTAD) was also investigated. Finite element models of one male and one female femur treated with a PFNA implant were developed considering the lag screw positioned centrally and inferiorly on the anteroposterior view, and for each of these, the screw tip at 4 discrete positions along its longitudinal axis. All 8 positions simulated for each femur considered the lag screw in a centre position on the lateral view. The risk of cut-out was evaluated for two loading conditions assuming it is related with high compressive strains. The bone region at the fracture line, near the tip of the missing medial fragment, was always the most concerning regarding high compressive strains. The inferior positioning of the lag screw reduced the volume of bone susceptible to yielding compared to the centre positioning. The deep placement of the screw tip improved the outcome for both centre and inferior positions. The results suggested the inferior and deep placement of the screw to be the best position to reduce the risk of cut-out. The volume of bone susceptible to yielding was found not to be correlated to TAD or CalTAD, suggesting that further investigation is necessary to identify other, more reliable, predictors of cut-out.

Medial collateral ligament release during knee arthroscopy: key concepts.

Complete access to the posterior medial compartment of the knee may represent a technical challenge during arthroscopy in patients with a tight tibiofemoral joint space.Medial collateral release reduces direct iatrogenic cartilage damage in the medial compartment of the knee through manipulation with instruments.We recommend performing medial collateral release in surgeries that access the posteromedial compartment (e.g. partial meniscectomy for ruptures of the posterior horn of medial meniscus or posterior root repairs) when the patient has a tight tibiofemoral joint space.There are two main techniques to perform medial collateral release: inside-out and outside-in. Regardless of the technique used, releasing medial ligament structures is a safe and effective method to be used in the diagnosis and treatment of injuries to the medial compartment. Cite this article: EFORT Open Rev 2021;6:669-675. DOI: 10.1302/2058-5241.6.200128.

Lack of Definition of Chronic Ankle Instability With Arthrometer-Assisted Ankle Joint Stress Testing: A Systematic Review of In Vivo Studies.

Despite extensive research on ankle instability a consensual and clear objective definition for pathological mechanical lateral ankle instability is yet to be determined. This systematic review aimed to summarize current available arthrometric devices, measuring methods and lateral ankle laxity outcomes in patients with chronic ankle instability that underwent objective arthrometric stress measurement. Sixty-eight studies comprising a total of 3,235 ankles with chronic ankle instability were included. Studies reported a wide range of arthrometric devices, testing position and procedures, and measuring methods. For the anterior drawer test, the average mean differences between injured and uninjured ankles ranged from -0.9 to 4.1 mm, and total translation in the injured ankle from 3.2 to 21.0 mm. Most common pathological threshold was ≥4 mm or ≥10 mm unilaterally and ≥3 mm bilaterally. For the talar tilt test, the average mean differences between injured and uninjured ankles ranged from 0.0° to 8.0°, and total tilt from injured ankle from 3.3 to 60.2°. Most common pathological threshold was ≥ 10° unilaterally and ≥ 6° mm bilaterally. It was found high heterogeneity in the scientific literature regarding the arthrometric devices, use of concomitant imaging and measuring methods of arthrometer-assisted anterior drawer and talar tilt tests which led to variable laxity outcomes in individuals with chronic ankle instability. Future studies should focus on standardizing the testing and measuring methods for an objective definition of mechanical ankle instability.

Chronic ankle instability has no correlation with the number of ruptured ligaments in severe anterolateral sprain: a systematic review and meta-analysis.

PURPOSE: Despite being a significant public health problem, ankle sprains' prognostic factors are largely unknown. This review aimed to systematically analyze the literature on acute ankle sprains to compare the prognosis of a combined anterior talofibular (ATFL) and calcaneofibular (CFL) ligaments rupture with an isolated ATFL rupture in terms of progression to chronic ankle instability and other clinical outcomes. METHODS: The databases for Pubmed, CENTRAL and Web of Science were searched. Clinical studies reporting the prognostic effect of combined ATFL-CFL rupture versus an isolated ATFL rupture in conservatively treated ankle sprains, with a minimum follow-up of 12 months, were eligible for inclusion. Only studies with a reliable diagnostic method for anterolateral ankle ligaments evaluation, namely ultrasonography, magnetic resonance imaging, arthrography or stress tenography, were included. The relative risk (RR), along with the 95% confidence interval (CI), was used to quantitatively analyze the main outcomes. RESULTS: Nine papers were selected for inclusion, of which five were suitable for quantitative analysis. None of them found a statistically significant correlation between ligament injury severity and progression to chronic instability. Concerning other clinical outcomes, three studies found a statistically significant correlation between a combined ligament injury and a worse clinical prognosis. From the quantitative analysis, the relative risk (RR) of chronic ankle instability in a single versus a combined ligament rupture showed no significant difference. CONCLUSION: A significant statistical correlation between a combined ATFL-CFL rupture and chronic ankle instability, compared to an isolated ATFL rupture, was not found. There is, however, fair evidence showing a worse clinical outcome score in the combined ruptures, as well as a decreased return to full sports activities. The use of reliable and accessible diagnostic methods to determine the number of ruptured ligaments might have a role in managing severe ankle sprains. LEVEL OF EVIDENCE: Level III.

Biomechanical study of autograft anatomic reconstruction in lateral ankle instability. / Estudio biomecánico de la reconstrucción ligamentosa anatómica con autoinjerto en la inestabilidad lateral de tobillo.

INTRODUCTION: The purpose of this work is perform a biomechanical comparison of anatomic reconstruction of the anterior talofibular ligament (ATFL) with the intact ATFL. MATERIALS AND METHODS: We studied 18 fresh cadaveric ankles with intact ATFL. Each specimen was clinically assessed with the anterior drawer (AD) and varus tilt (VT) tests and the angular movement in the three spatial planes (axial, coronal and sagittal) was measured with an arthrometer using a sensor located in the talus. RESULTS: Statistically significant differences were found in the axial plane, between the intact ATFL versus the sectioned ATFL for AD test with p = 0.012, and for VT test with p = 0.013. Regarding the coronal plane, we also observed a statistically significant difference for VT test with p = 0.016. In the sagittal plane, there are no statistically significant differences in both maneuvers. No statistically significant differences were found when comparing the biomechanics of anatomic ligament reconstruction versus the intact ATFL. CONCLUSION: Autograft anatomic reconstruction of the ATFL showed biomechanical properties similar to those of the native ATFL, at the zero moment in a cadaveric model.

The tibiocalcaneal bundle of the deltoid ligament - Prevalence and variations.

INTRODUCTION: A precise understanding of the anatomy of the multiple bundles of the deltoid ankle ligament might have clinical impact. The most relevant deltoid anatomical series report a variable frequency of the tibiocalcaneal ligament, possibly the most important bundle to be reconstructed in medial ankle insufficiency. Our purpose was to access the deltoid's tibiocalcaneal ligament morphology in a large anatomical study as well as to perform a historical literature review on the reasons for its variable prevalence. MATERIALS AND METHODS: Forty-three ankle specimen were dissected to describe the prevalence of superficial and deep deltoid bundles, with special attention to the tibiocalcaneal ligament and its variants. RESULTS: All ankles had distinct deep and superficial bundles. In all 43 ankles the tibionavicular and tibiospring ligaments were clearly identified. The superficial posterior tibiotalar ligament was identified in 38 ankles (88%). The deep anterior tibiotalar bundle was identified in 35 ankles (81%). The deep posterior tibiotalar bundle was identified in all ankles. The tibiocalcaneal ligament was identified in 33 ankles (77%). In ten ankles there wasn't a direct bundle between the tibia and the sustentaculum tali. In all of these, however, we found some fibers spanning the gap between the tibiospring ligament and the sustentaculum tali. CONCLUSION: The tibiocalcaneal ligament is present in most specimens. In those in which we could not identify a direct bundle between the tibia and the calcareous we found a variant of the tibiospring ligament that connects to the sustentaculum tali.

The vascularization of the peroneal tendons: An anatomic study.

BACKGROUND: Arterial vascularization is intimately related to the peroneal tendon ruptures. Our purpose is to describe the vascular anatomy of peroneal tendons and assess differences in the vascularization patterns between peroneus brevis tendon (PBT) and peroneus longus tendon (PLT). METHODS: Anatomical study of 22 cadaveric lower extremities. We exposed tendons' vascularization by injecting latex. To systematize the vascular description, we considered four anatomical regions in the PBT and six in the PLT. RESULTS: Vascularization was supplied by the peroneal, anterior tibial and lateral plantar arteries and from the deep plantar arch through the vincula connecting the tendons. No avascular areas were found in the PLT. 22.7% of specimens had avascular areas in the PBT. Two visual vascularization patterns were found (arcuate and weblike). Increasing age and a web-like vascularization were associated with a lower number of blood vessels at the tendons' post malleolus area. CONCLUSION: Peroneal tendons are well vascularized throughout their course, running through a common vincula, with vascularization provided by various arteries. Avascular areas were observed in the PBT, but none at the PLT.

Anatomic Arthroscopic Graft Reconstruction of the Interosseous Talocalcaneal Ligament for Subtalar Instability.

Instabilities of the subtalar joint are commonly overlooked or mismanaged, and chronic instability is a debilitating condition leading to premature joint degeneration. Several methods of treatment have been described, mainly screw fixation, arthrodesis, or ligament reconstruction. Most studies describe open methods for ligament reconstruction. We describe an original technique for "all-inside" arthroscopic graft reconstruction of the interosseous talocalcaneal ligament for subtalar instability.

Achilles tendon elongation after acute rupture: is it a problem? A systematic review.

PURPOSE: Rupture of the Achilles tendon (AT) is a common injury. Strength deficits may persist over the long term, possibly owing to elongation of the tendon or inferior mechanical properties. This study aimed to provide a systematic review of the literature on the prevalence and consequences of tendon elongation in patients after acute AT rupture treatment. It was hypothesized that an elongated tendon would be associated with a worse clinical outcome. METHODS: The databases for MEDLINE, CENTRAL and Web of Science were searched. Clinical studies related to AT rupture reporting tendon elongation and clinical or functional outcomes, with a minimum follow-up of 6 months, were eligible for inclusion. Only studies testing for statistical correlations (SCs) between AT elongation and other outcomes were eligible, with the exception of biomechanical studies in which statistically significant AT elongation was found to be a generalized finding in the study group. For these studies to be eligible, the study group had to be compared with a healthy control group, or the injured limb compared with the uninjured limb, regarding biomechanical parameters. RESULTS: Twenty-eight papers were selected for inclusion. Mean AT elongation measured with imaging techniques ranged from 0.15 to 3.1 cm (n = 17). Ten studies investigated SCs with Patient Reported Outcome Measures (PROMs), in which two found SCs with tendon elongation. Five studies reported strength and power evaluations and their correlation with AT elongation, with two having found SCs between decreased strength and tendon elongation. In ten studies reporting data on biomechanical tests, nine found influence of tendon elongation. In this group, four out of five studies found SCs with biomechanical parameters. CONCLUSION: Fair evidence of the influence of tendon elongation in biomechanical parameters was found. In a general population, evidence of a detrimental effect of tendon elongation on PROMs or functional strength at follow-up was not found in this review. LEVEL OF EVIDENCE: Level IV.

Varus talar tilt combined with an internal rotation pivot stress assesses the supination instability vector in lateral ankle ligaments' injury - cadaver study.

BACKGROUND: The lack of consensus on the relevance of the varus talar tilt test (VTTT) might be due to the divergence between the insufficiency vector of lateral ankle instability and the direction of this clinical test. Our hypothesis is that the VTTT is more accurate to diagnose lateral ankle ligaments rupture when it's applied with a pre-positioning of the foot in internal rotation (IR). METHODS: We compared, in 12 cadaver ankles, the varus opening during a classic VTTT with the same test starting in an IR pivot, using a new arthrometer. RESULTS: The classic VTTT caused a 13° tilt after ATFL section and 23,8° after ATFL and CFL section. The application of a VTTT with an IR prepositioning caused a 21,2° tilt after ATFL section (p = 0,002) and 29,5° after ATFL and CFL section (p = 0,006). CONCLUSION: The VTTT is better to identify lateral ankle ligaments' insufficiency when it's applied with a pre-positioning of the foot in internal rotation. The resulting vector is similar to the supination trauma.

Irreducible Acute Patellar Dislocation due to a New Anatomical Variant - the Notched Patella.

Irreducible patella dislocations are rare and are usually associated with complex mechanisms. The authors report the clinical case of an irreducible lateral patellar dislocation due to an anatomical variant. The authors assisted a 16-year-old patient who presented with a lateral patella dislocation that was impossible to reduce by closed manipulation, even under general anesthesia. During the imaging study, the computed tomography (CT) exam showed a notch in the medial facet of the patella, impacted in the lateral condyle, which prevented the reduction. This anatomical variant was later confirmed during surgery. In a bilateral follow-up CT, this variant was also present in the contralateral, normal knee, excluding traumatic reshaping as the reason for this patellar notch. The authors used a medial parapatellar approach for open reduction of the dislocation and to repair the medial retinaculum. According to Wiberg, there are three different patella types. The authors describe a variation of type III patella with a notch in the medial border that is not included in the previous classification. They emphasize the importance of a CT study in the presence of an irreducible dislocation and the recognition of this anatomical variant of the patella, as further aggressive maneuvers have proven to be unsuccessful. Open reduction appears to be the best option in this scenario.

Irreducible Acute Patellar Dislocation due to a New Anatomical Variant - the Notched Patella / Dislocação patelar aguda irredutível devido a uma nova variante anatômica - a patela entalhada

Abstract Irreducible patella dislocations are rare and are usually associated with complex mechanisms. Theauthors report the clinical case of an irreducible lateral patellardislocationdueto an anatomical variant. The authors assisted a 16-year-old patient who presented with a lateral patella dislocation that was impossible to reduceby closedmanipulation, even under general anesthesia. During the imaging study, the computed tomography (CT) exam showed a notch in the medial facet of the patella, impacted in the lateral condyle, which prevented the reduction. This anatomical variant was later confirmed during surgery. In a bilateral follow-up CT, this variant was also present in the contralateral, normal knee, excluding traumatic reshaping as the reason for this patellar notch. The authors used a medial parapatellar approach for open reduction of the dislocation and to repair themedial retinaculum. According to Wiberg, there are three different patella types. The authors describe a variation of type III patellawith a notch inthemedial border that is not included in the previous classification. They emphasize the importance of a CTstudy in the presence of an irreducible dislocation and the recognition of this anatomical variant of the patella, as further aggressive maneuvers have proven to be unsuccessful. Open reduction appears to be the best option in this scenario.

Resumo As luxações irredutíveis da patela são raras e são geralmente associadas a mecanismos complexos. Os autores relatam o caso clínico de uma luxação patelar lateral irredutível devido a uma variante anatômica. Os autores atenderam um paciente de 16 anos que apresentou uma luxação lateral da patela de redução impossível por manipulação fechada, mesmo sob anestesia geral. Durante o estudo de imagem, a tomografia computadorizada (TC) mostrou um entalhe na faceta medial da patela, impactada no côndilo lateral, o que impediu a redução. Esta variante anatômica foi posteriormente confirmada durante a cirurgia. Em uma TC bilateral de acompanhamento, esta variante anatômica também estava presente no joelho contralateral, normal, excluindo o remodelamento traumático como o motivo deste entalhe patelar. Os autores utilizaramuma abordagem parapatelar medial para a redução aberta do deslocamento e para o reparo do retináculo medial. De acordo comWiberg, existem três tipos diferentes de patela. Os autores descrevem uma variação da patela de tipo III com um entalhe na margem medial que não está incluída na classificação anterior. Ressalta-se a importância de um estudo de TC na presença de luxação irredutível e o reconhecimento desta variante anatômica da patela, já quemanobras agressivas foram testadas sem sucesso. A redução aberta parece ser a melhor opção neste cenário. Abstract Irreducible patella dislocations are rare and are usually associated with complex mechanisms. The authors report the clinical case of an irreducible lateral patellar dislocation due to an anatomical variant. The authors assisted a 16-year-old patient

Peri-prosthetic bone cysts after total ankle replacement. A systematic review and meta-analysis.

BACKGROUND: Periprosthetic cystic osteolysis is a well-known complication of total ankle replacement. Several theories have been proposed for its aetiology, based on individual biomechanical, radiological, histopathology and outcome studies. METHODS: Studies that met predefined inclusion/exclusion criteria were analysed to identify literature describing the presence of peri-prosthetic ankle cystic osteolysis. Quantitative data from the selected articles were combined and statistically tested in order to analyse possible relations between ankle peri-prosthetic bone cysts and specific implant characteristics. RESULTS: Twenty-one articles were elected, totalizing 2430 total ankle replacements, where 430 developed peri-prosthetic cystic osteolysis. A statistically significant association (P<.001) was found between the presence of bone cysts and non-anatomic implant configuration, hydroxyapatite-coating, mobile-bearing and non tibial-stemmed implants. No significant association existed between the type of constraining and the presence of cysts (P>.05). CONCLUSIONS: Non-anatomic, mobile-bearing, hydroxyapatite-coated and non tibial-stemmed total ankle replacements are positively associated with more periprosthetic bone cysts.

Repair with bicortical suspension device restores proximal tibiofibular joint motion.

PURPOSE: Dislocation of the proximal tibiofibular joint is a complex injury that is often overlooked or misdiagnosed. Surgical treatment is recommended for severe acute or for chronic symptomatic instability but there is still no evidence on the optimal reconstruction technique. The purpose of this study is to analyze the motion of the proximal tibiofibular joint after repair with a bicortical suspension device as compared to its normal kinematics. METHODS: Kinematic analysis of the proximal tibiofibular joint was performed during continuous passive motion of the knee and ankle in 7 whole body cadavers in a controlled laboratory study. The 14 knees were measured in four conditions: (1) intact; (2) repair with transarticular bicortical suspension device tensioned to 40 N; (3) the same repair tensioned to 50 N; and (4) the repair tensioned to 50 N after interosseous syndesmotic membrane sectioning. RESULTS: Proximal tibiofibular joint can be successfully repaired by a bicortical suspension device restoring its normal 3D spatial motion. The fixation of the PTFJ with the device tested tensioned to 40 or 50 N could restore the intact joint kinematics for every movement tested except knee internal and external rotation. The fixation to 40 N attained closer values to the intact joint in the movements that evolve the anterior PTFJ ligament. The 50 N fixation is overall more rigid than the intact joint but statistically closer to the normal PTFJ kinematics for the movements more dependent on the posterior PTFJ ligament. Sectioning of the interosseous syndesmotic membrane determined an important loss of stability of the PTFJ during the movements of ankle extension and ankle flexion. Such loss illustrates the relevance of this associated injury when planning PTFJ ligament reconstruction. CONCLUSIONS: This study indicates that the repair of the proximal tibiofibular joint with a transarticular bicortical suspension device tensioned to 40 and 50 N can restore the normal kinematics of this joint. Based on these findings, Surgeons may consider this option as a reliable solution when planning successful treatment for proximal tibiofemoral joint instability.

Kinematics of the proximal tibiofibular joint is influenced by ligament integrity, knee and ankle mobility: an exploratory cadaver study.

PURPOSE: The proximal tibiofibular joint (PTFJ) is a rather unknown articulation. There is little understanding of its anatomy, physiology, and functional role. The objectives of this research are to describe the normal kinematics of the PTFJ and its relation to the ankle and knee movements. METHODS: Fourteen knees of seven adult fresh frozen whole body cadavers were studied. The proximal tibiofibular joint and ligaments were identified, after which we sequentially sectioned the anterior proximal tibiofibular ligament (APTFL), the posterior proximal tibiofibular ligament (PPTFL), and the interosseous syndesmotic membrane. Models with intact and sectioned ligaments were compared, while the unloaded lower limb was manually mobilized in a pre-defined sequence of combined movements of knee, ankle, and proximal tibiofibular joints. The PTFJ spatial displacement was measured by analyzing the length of a distance vector between two 3D coordinate systems settled over the tibia and fibula. RESULTS: On the unaltered PTFJ, direct grasping of the head of the fibula with the hip in 45° of flexion and the knee in 90° of flexion was found to produce an average displacement of 7 mm. Knee movements caused the greatest spatial displacements, almost ten times the ones produced by ankle flexion/extension. Flexion/extension of the knee caused 1.8 times more displacement than single rotations with the knee flexed to 90°. It was found that the APTFL was an important stabilizer of the PTFJ when this joint is tensioned accommodating the movements of ankle extension and foot eversion. The APTFL was not a significant stabilizer of the PTFJ during direct manipulation of the fibular head when imprinting a manual force with posterior direction. The PPTFL was an important accommodator of ankle flexion, foot inversion and knee flexion. The interosseous syndesmotic membrane also proved to be a significant PTFJ stabilizer in rotational movements of the ankle and knee. CONCLUSIONS: This is the first cadaver study to illustrate the PTFJ normal spatial displacement, thereby contributing to a deeper insight of this joint. The contribution of each ligament for PTFJ stability was described and, based on these findings; a new mechanism of injury was suggested. Surgeons can translate the results of this study into the clinical practice.