Efficacy of reconstruction with half of peroneous longus tendon autograft for the treatment of chronic Achilles tendon rupture combined with tendon defects / 中华创伤杂志

Objective:To evaluate the outcomes of reconstruction with half of peroneous longus tendon autograft for the treatment of chronic Achilles tendon rupture combined with tendon defects.Methods:A retrospective case series study was conducted on the clinical data of 14 patients with chronic tendon rupture combined with defects admitted to Orthopedic Sports Medicine Center, West China Hospital, Sichuan University from November 2017 to August 2020, including 11 males and 3 females, aged 26-62 years [(42.8±10.7)years]. All the patients underwent Achilles tendon reconstruction with half of peroneus longus tendon autograft. American Orthopedic Foot and Ankle Society (AOFAS) score, Achilles tendon total rupture score (ATRS) and Visual Analogue Scale (VAS) were compared before surgery, at 12 months after surgery and at the last follow-up. At the last follow-up, MRI of the injured ankle was prescribed to evaluate tendon healing; Thomspon test was performed and the patients were asked to do single-leg heel raise; the patients were asked about their conditions in returning to daily life activities and sports. Postoperative complications were observed.Results:All the patients were followed up for 24-47 months [(35±9)months]. AOFAS score, ATRS and VAS at 12 months after surgery were (87.9±6.6)points, (80.9±2.4)points and (2.0±0.3)points respectively, superior to those before surgery [(52.7±16.9)points, (42.0±4.4)points and (4.1±0.4)points respectively] ( P<0.05). The afore-mentioned results at the last follow-up were (95.2±7.2)points, (85.9±2.5)points and (0.8±0.3)points respectively, superior to those at 12 months after surgery ( P<0.05). MRI images of the affected ankle joints showed satisfactory healing of the reconstructed Achilles tendon at the last follow-up. All the patients, being negative in Thompson test at the last follow-up, were able to complete the heel lift on the affected side. All the patients resumed activities of daily living at the last follow-up, among whom 5 resumed to moderate- to high-intensity sports activities, such as basketball sport, and moderate-to high-intensity physical training, 5 resumed light-intensity sports activities such as jogging and swimming, and the other 4 did not resume sports due to fear of re-injury or aging. One patient had delayed wound healing, which was considered gout-related. One patient complained about mild pain at the Achilles tendon in cold weather or after long walks. No re-rupture of the Achilles tendon occurred. No patient complained about discomfort at the graft harvest site, calcaneal valgus or restricted ankle plantar flexion. Conclusions:For patients with chronic Achilles tendon rupture combined with tendon defects, reconstruction with half of peroneous longus tendon autograft facilitates postoperative spinal function recovery and pain alleviation, achieves satisfaction with the returning to daily activity and sports, and has few complications.

Minimally Invasive Suture Technique Pull-out to Repair the Acute Flexor Tendons in Zone II of the Hand / Técnica de sutura minimamente invasiva pull-out para reparar lesões agudas dos tendões flexores da zona II da mão

Abstract Objective: To evaluate the safety and effectiveness of a modified pull-out suture technique in patients undergoing primary repair surgery for injuries to the flexor tendons of the fingers with Total Active Motion (TAM) as the primary outcome. Method: A total of 29 patients (38 fingers) were chosen from both sexes, aged between 18 and 65 years with clean acute tendon laceration occurring within 15 days, in the Verdan's zone II of flexor tendon in the hand, when only the deep flexor tendon was sutured, either associated or not with digital nerve injury. The patients were operated on using the proposed technique and evaluated at 3, 9 and 24-weeks PO. The primary outcome was the assessment of Total Active Movement (TAM) and 3 classifications were employed: Strickland, IFSSH and Buck-Gramcko. Results: We observed a total active motion (TAM) of 209.3 °at the end of 24 weeks; 83.0% of Good and Excellent results by the Modified Strickland Classification, 93% of Excellent results by the IFSSH Classification, and 97% of Good and Excellent results using the Buck-Gramcko Classification. There were no cases of rupture, but tendon adhesion was observed in 3 fingers. Conclusion: The present suture technique proved to be safe and effective with a low rate of complications, obtaining an excellent functional result in terms of total active mobility, according to the evaluations and classifications used.

Resumo Objetivo: Avaliar a segurança e a efetividade da técnica de sutura pull-out modificada nos pacientes submetidos à cirurgia de reparo primário das lesões dos tendões flexores nos dedos, tendo como desfecho primário o movimento ativo total (TAM). Método: Foram escolhidos 29 pacientes (38 dedos), de ambos os sexos, com idade entre 18 e 65 anos, com laceração tendinosa aguda e limpa, ocorrida em até 15 dias, na zona II de Verdan do tendão flexor da mão, quando apenas o tendão flexor profundo foi suturado, associada ou não à lesão do nervo digital. Os pacientes foram operados pela técnica proposta e avaliados em 3, 9 e 24 semanas PO. O desfecho primário foi a avaliação do movimento ativo total (TAM) e foram empregadas 3 classificações: Strickland, IFSSH e Buck-Gramcko. Resultados: Observamos um movimento ativo total (TAM) de 209,3° ao final de 24 semanas; 83,0% de resultados Bons e Excelentes pela Classificação de Strickland Modificada, 93% de resultados Excelentes pela Classificação IFSSH e 97% de resultados Bons e Excelentes pela Classificação Buck-Gramcko. Não houve casos de ruptura, mas foi observada aderência tendínea em 3 dedos. Conclusão: A presente técnica de sutura mostrou-se segura e eficaz com baixo índice de complicações, obtendo excelente resultado funcional em termos de mobilidade ativa total, de acordo com as avaliações e classificações utilizadas.

Quadricipital Tendon Simultaneous Bilateral Tear in a Patient with Type-II Diabetes Mellitus after Low-energy Trauma: Case Report / Ruptura bilateral simultânea do tendão quadricipital em paciente portador de diabetes mellitus do tipo II após trauma de baixa energia: Relato de caso

Abstract Simultaneous bilateral rupture of the quadricipital tendon is an extremely rare lesion. We report a case of this injury after low-energy trauma in a patient with type-II diabetes mellitus. Both knees were surgically approached in the same surgical procedure. Early rehabilitation is essential for the adequate functional recovery of the knee. The aim of the present report was to describe an atypical case of this type of injury after minimal trauma, as well as to detail the surgical technique used to treat it.

Resumo A ruptura bilateral simultânea do tendão do quadríceps é uma lesão extremamente rara. Relatamos um caso desta lesão após trauma de baixa energia em paciente portador de diabetes mellitus do tipo II. O diagnóstico é essencialmente clínico, e requer tratamento precoce. Os dois joelhos foram abordados cirurgicamente no mesmo ato operatório. A reabilitação precoce é fundamental para a recuperação funcional adequada do joelho. O objetivo deste relato foi descrever um caso atípico deste tipo de lesão após trauma mínimo, bem como detalhar a técnica cirúrgica utilizada para o tratamento.

Acute Distal Biceps Tendon Injury: Diagnosis and Treatment / Lesões agudas do tendão distal do bíceps: Diagnóstico e tratamento

Abstract Acute distal biceps injuries clinically present with sudden pain and acute loss of flexion and supination strength. The main injury mechanism occurs during the eccentric load of the biceps. The hook test is the most significant examination test, presenting the highest sensibility and specificity for this lesion. Magnetic resonance imaging, the gold standard imaging test, can provide information regarding integrity and identify partial and/or complete tears. The surgical treatment uses an anterior or double approach and several reattachment techniques. Although there is no clinical evidence to recommend one fixation method over the other, biomechanical studies show that the cortical button resists better to failure. Although surgical treatment led to an 89% rate of return to work in 14 weeks, the recovery of high sports performance occurred in 1 year, with unsustainable outcomes.

Resumo As lesões agudas do tendão distal do bíceps se apresentam, clinicamente, com uma dor súbita associada a perda aguda de força de flexão e supinação. Seu principal mecanismo de lesão ocorre durante contração excêntrica do bíceps. O "Hook Test" é o principal teste semiológico, sendo o mais sensível e específico. A ressonância magnética, exame padrão ouro para o diagnóstico, pode fornecer informações sobre a integridade, identificando as lesões parciais e/ou completas. O tratamento cirúrgico pode ser realizado por duas vias principais: anterior e por dupla via porém as técnicas de reinserção tendínea são diversas não havendo evidência clínica que recomende um método de fixação em detrimento ao outro; embora o botão cortical apresente maior resistência a falha nos estudos biomecânicos. Com o tratamento cirúrgico o retorno as atividades laborais foi de 89% em 14 semanas (média) porém ao esporte de alto rendimento o prazo foi longo, média de 1 ano, e não duradouro.

Early or Delay? The Most Suitable Rehabilitation Protocol for "No Man's Land" Injury: Meta-Analysis with Trial Sequential Analysis - 20 Years Trends / Precoce ou tardio? O protocolo de reabilitação mais adequado para lesão na região 'terra de ninguém': Metanálise com análise sequencial de ensaios - Tendências de 20 anos

Abstract Objective The aim of this study is to analyze various rehabilitation protocol and determine which methods will yield a better outcome. Methods The database reports were searched within 1990 until 2020, using PubMed, Cochrane library database, Ovid, Medline, and the other several published trials. A statistical analysis was made from Review Manager and Trial Sequential Analysis (TSA). Result The mean of re-rupture rate is 3.3% (n= 8) in the combination protocol until 8% (n= 48) in CAM protocol. Meta-analyses found no significant difference between Kleinert vs CAM in re-rupture rate. Also no significant difference in Duran vs CAM in rerupture rate. In Trial Sequential Analysis (TSA), the z-curve does not cross both of the trial sequential boundaries, a further trial with larger sample will be required. The TSA of flexion contracture CAM vs Kleinert was indicated that CAM protocol may be superior than Kleinert to reduce the incidence of flexion contracture. For the range of mean flexion contracture 6.6% (n= 18) in CAM to 23.6% (n= 76) in Kleinert protocol. Conclusion Current meta-analysis proposed that the combination technique will result less re-rupture incidence and better functional outcome in flexor zone II injuries than other techniques. The CAM method also results less flexion contracture than others. However, a further meta-analyses with larger sample trials will be required to confirm this review's conclusion.

Resumo Objetivo O objetivo deste estudo é analisar vários protocolos de reabilitação e determinar quais métodos produzem um melhor resultado. Métodos Os relatórios dos bancos de dados foram pesquisados entre 1990 e 2020, usando PubMed, banco de dados da biblioteca Cochrane, Ovid, Medline e vários outros ensaios publicados. Uma análise estatística foi feita a partir do Review Manager e Trial Sequential Analysis (TSA). Resultado A taxa média de re-ruptura é de 3,3% (n = 8) no protocolo combinado, e até 8% (n = 48) no protocolo de Movimento Ativo Controlado (MAC). As metanálises não encontraram diferença significativa entre Kleinert vs MAC na taxa de re-ruptura. Também não há diferença significativa entre Duran e MAC na taxa de re-ruptura. Na Trial Sequential Analysis (TSA), a curva z não cruza ambos os limites sequenciais de ensaio, será necessário um ensaio adicional com amostra maior. A TSA de contratura em flexão MAC vs Kleinert indicou que o protocolo MAC pode ser superior ao Kleinert para reduzir a incidência de contratura em flexão. Para a faixa de contratura média em flexão de 6,6% (n = 18) no MAC a 23,6% (n = 76) no protocolo Kleinert. Conclusão A metanálise atual propôs que a técnica combinada resultará em menor incidência de re-ruptura e melhor resultado funcional em lesões da zona flexora II do que outras técnicas. O método MAC também resulta em menos contratura em flexão do que outros. No entanto, serão necessárias mais metanálises com estudos com amostras maiores para confirmar a conclusão desta revisão.

Rotura aguda del tendón de Aquiles tratadas quirúrgicamente con Técnica de Mínimo Abordaje. Resultados clínicos y funcionales a un año de seguimiento / Acute rupture of the Achilles tendon surgically treated with the Minimal Approach Technique. Clinical and functional results at one year of follow-up

Se deben tener consideraciones especiales cuando se realizan reparaciones quirúrgicas del tendón de Aquiles. Su anatomía e irrigación particular plantean desafíos únicos para el manejo, y tener comprensión profunda de estas características es crucial para escoger el tratamiento adecuado y lograr resultados exitosos. El objetivo de este trabajo es analizar la eficiencia de la reparación quirúrgica de la rotura aguda del tendón de Aquiles con técnica de Dresden, entre el 2015 y el 2021. Se realizó un estudio de tipo analítico, observacional, longitudinal y prospectiva. El análisis del aspecto estadístico fue a través de estadística descriptiva y asociación de las variables. Se incluyeron 34 pacientes con un promedio de 42 años, la mayoría de sexo masculino. Al aplicar las escalas VISA-A se obtuvo un promedio de 12 puntos, 67,5 puntos a los 6 meses y 80,5 puntos a los 12 meses. En la encuesta SF-12 a los 6 meses se obtuvo un promedio de 68,5 puntos y 80 puntos a los 12 meses; un paciente presentó rechazo de la sutura y 6 afirmaron algún grado de edema residual aun al año de la cirugía. La reparación quirúrgica con técnica de Dresden mejora la funcionabilidad del tendón de malos resultados a regulares y buenos resultados al año de seguimiento. El 68% de la población estudiada afirmó que se encuentran satisfechos con la cirugía(AU)

Special considerations must be made when performing surgical repairs of the Achilles tendon. Its particular anatomy and blood supply pose unique management challenges, and a thorough understanding of these characteristics is crucial to choosing the right treatment and achieving successful results. The objective of this work is to analyze the efficiency of the surgical repair of the acute rupture of the Achilles tendon with the Dresden technique, between 2015 and 2021. An analytical, observational, longitudinal and prospective study was carried out. The analysis of the statistical aspect was through descriptive statistics and association of the variables. 34 patients with an average age of 42 years were included, most of them male. When applying the VISA-A scales, an average of 12 points was obtained, 67,5 points at 6 months and 80,5 points at 12 months. In the SF-12 survey at 6 months an average of 68,5 points and 80 points at 12 months were obtained; One patient presented rejection of the suture and 6 reported some degree of residual edema even one year after surgery. Surgical repair with the Dresden technique improves the functionality of the tendon from poor to regular results and good results after a year of follow-up. 68% of the population studied stated that they are satisfied with the surgery(AU)

Research progress in the measurement and influencing factors of tendon elongation following acute Achilles tendon rupture / 中华创伤杂志

Acute Achilles tendon rupture (AATR) is one of the most common sport injuries in clinical practice, which is usually treated surgically or non-surgically. Regardless of treatment choice, early weight bearing should be encouraged to promote tendon healing. After ruptured Achilles tendon is healed, permanent defects in the biomechanical function of the patients′ affected lower limbs are found and performance in running, jumping, and competitive sports is affected, which may be due to a decrease in the flexion strength of the ankle as a result of tendon elongation following the repair of an Achilles tendon. The methods for evaluating tendon elongation can be divided into indirect measurement and direct measurement. Achilles tendon resting angle (ATRA) is the most commonly used and reliable indirect measurement index, while ultrasound and MRI are commonly used for direct measurement. However, there is no recommended "gold standard" at present. Among the potential influencing factors of tendon elongation, the choice of surgical or non-surgical treatment, different tendon suturing methods and start time of weight bearing have attracted attention and are still controversial. The authors reviewed the research progress of tendon elongation's effects on lower limb biomechanics, evaluation of tendon elongation, and factors affecting tendon elongation so as to provide reference for clinical diagnosis and treatment as well as related researches.

Outcomes of using long head of biceps tendon transposition to augment arthroscopic massive rotator cuff repair / 中华创伤杂志

Objective:To investigate the outcome of using long head of biceps tendon (LHBT) transposition to augment arthroscopic massive rotator cuff repair.Methods:A retrospective case series study was performed on 22 patients with massive rotator cuff tear treated in Zhongshan Hospital, Xiamen University from June 2019 through July 2020, including 12 males and 10 females, aged 54-79 years [(63.9±6.8)years]. LHBT transposition was performed to augment arthroscopic repair of massive rotator cuff tear. The active range of motion (forward flexion, abduction, external rotation), visual analog scale (VAS), University of California Los Angeles (UCLA) score and American Shoulder and Elbow Surgeons (ASES) score were compared preoperatively and at 3 months and 12 months postoperatively. The cuff integrity was evaluated using MRI following Sugaya classification at 12 months postoperatively. LHBT dislocation or distal retraction was recorded at the last follow-up.Results:All patients were followed up for 12-24 months [(17.0±3.8)months]. The postoperative 3-month active forward flexion [162.5(160.0, 170.0)°] and abduction [170.0(160.0, 170.0)°] were improved compared with preoperative measurements [90.0(73.8, 120.0)°,85.0(70.0, 112.5)°](all P<0.05). However, no statistically significant difference was found between the preoperative and postoperative 3-month external rotation [50.0(37.5,60.0)° vs. 60.0(48.8,70.0)°] ( P>0.05). The postoperative 12-month active forward flexion, abduction and external rotation were 170.0(160.0, 175.0)°, 170.0(170.0, 177.8)° and 60.0(48.8, 70.0)°, showing no significant improvement from those at 3 months postoperatively (all P>0.05). The postoperative 3-month VAS [1.0(0.8, 2.0)points], UCLA score [23.0(23.0, 25.0)points] and ASES score [79.1(72.9, 83.3)points] were improved significantly compared with preoperative measurements [7.0(8.0, 9.0)points, 9.0(10.0, 14.0)points, 25.0(16.6, 31.6)points] (all P<0.05). The postoperative 12-month UCLA score [33.0(31.0, 35.0)points] and ASES score [91.6(86.6, 93.3)points] were further improved compared with those at 3 months postoperatively (all P<0.05). However, the postoperative 12-month VAS [0.0 (0.0, 1.0)points] showed no statistically significant difference with that at 3 months postoperatively ( P>0.05). The UCLA score was excellent in 6 patients and good in 16 at 12 months postoperatively.MRI revealed healed tendons with continuity in 16 patients, with the healing rate of 72.7%, and partially retears with good shoulder function in 6 patients, with the retearing rate of 17.3%. No LHBT dislocation or distal retraction was found at 12 months postoperatively in regardless of mild anterior shoulder pain in 2 patients. Conclusion:Using LHBT transposition to augment arthroscopic massive rotator cuff repair has yielded excellent shoulder range of motion, shoulder function recovery, pain relief and high tendon healing rate with rare postoperative complication.

Estudio de las heridas por amoladora tratadas en el Hospital de Clínicas y Hospital Pasteur, Montevideo, Uruguay / Grinder injuries treated at the Clínicas and Pasteur Hospital of Montevideo, Uruguay / Estudo das lesões por esmerilhadeira tratadas no Hospital de Clínicas e Hospital Pasteur, Montevidéu, Uruguai

Resumen: Introducción: las heridas causadas por amoladora representan una consulta frecuente al cirujano plástico en nuestro país. Los objetivos del presente trabajo fueron conocer la epidemiología de los pacientes que consultaban con estas lesiones, conocer las circunstancias del accidente y estudiar si existía relación entre las condiciones de uso de la herramienta y la gravedad de las lesiones. Material y método: se realizó un estudio descriptivo, transversal, donde se recabaron los datos de los pacientes que consultaban por heridas por amoladora en las puertas de emergencia de Hospital Pasteur y Hospital de Clínicas en un período de 6 meses. Resultados: un total de 76 pacientes fueron incluidos en el estudio, la mayoría de sexo masculino, en edad laboral activa (39 a 58 años) dedicados a la realización de trabajos temporales o tareas de construcción, con bajo nivel de instrucción. El 84% de las heridas fueron graves. El 61% de los pacientes no utilizó los elementos de seguridad de la herramienta al momento del accidente. La mayoría de las lesiones se produjeron fuera del ambiente laboral. Conclusiones: en base a nuestro trabajo pudimos establecer el perfil epidemiológico de la población más susceptible de sufrir estas lesiones. Comprobamos que las heridas producidas por amoladora son en su mayoría graves y requieren procedimientos complejos para su resolución.

Summary: Introduction: grinder injuries represent a large number of consultations for plastic surgeons in our country. This study aims to learn about the epidemiological characteristics of patients who consulted for these lesions and the circumstances of the accidents, and to analyze whether there is a relationship between the conditions for tool use and the severity of lesions. Methodology: we conducted a retrospective, descriptive, transversal study where we collected data from the patients who consulted for grinder injuries at the emergency departments of Pasteur and Clínicas Hospital during a 6-month period. Results: seventy-six patients were included in the study, most of which were male working adults (between 39 and 58 years-old) who had temporary jobs or were performing construction works and had low levels of education. 84% of lesions were severe. 61% of patients did not respect safety regulations at the time of the accident. Most lesions occurred out of working hours. Conclusions: based on our study, we could identify the epidemiological profile of the most vulnerable population for this kind of lesions. We proved that most grinder lesions are severe and their management requires complex procedures.

Resumo: Introdução: as lesões causadas por esmerilhadeira são causa frequente de consulta ao cirurgião plástico no Uruguai. Os objetivos do presente trabalho foram conhecer as características dos pacientes que consultaram com essas lesões, conhecer as circunstâncias do acidente e analisar a possível relação entre as condições de uso da ferramenta e a gravidade das lesões. Metodologia: foi realizado um estudo descritivo, transversal, onde foram coletados dados de pacientes que consultaram por lesões de esmerilhadeira no pronto-socorro do Hospital Pasteur e Hospital de Clínicas durante um período de 6 meses. Resultados: foram incluídos no estudo 76 pacientes, a maioria do sexo masculino, em idade ativa para trabalhar (39 a 58 anos) dedicados à realização de trabalhos temporários ou trabalhos na construção civil, com baixo nível de escolaridade. 84% dos ferimentos foram graves. 61% dos pacientes não utilizaram os elementos de segurança da ferramenta no momento do acidente. A maioria das lesões ocorreu fora do ambiente de trabalho. Conclusões: com base em nosso trabalho conseguimos estabelecer o perfil da população mais suscetível a esses agravos. Constatamos que a maioria das lesões causadas por esmerilhadeiras são graves, exigindo procedimentos complexos para sua resolução.

Reconstrução do antebraço com matriz dérmica acelular após excisão de neurofibroma plexiforme gigante: relato de casos / Forearm reconstruction with acellular dermal matrix after giant plexiform neurofibroma excision: case reports

Introdução: O neurinoma plexiforme gigante é um neuroectoderma e uma doença hereditária. É um tumor cutâneo incomum associado à NF1, caracterizado como um tumor benigno da bainha do nervo periférico envolvendo múltiplos fascículos nervosos. Os objetivos da reconstrução da cobertura do antebraço são proteger as estruturas que vão até o punho e a mão e evitar cicatrizes que levem à perda de movimento. Tanto o antebraço quanto a mão desempenham papéis funcionais e sociais. O manejo bem-sucedido de feridas complexas é necessário para a reabilitação funcional geral desses pacientes. Relato do Caso: Paciente do sexo feminino, 31 anos, apresentou-se na divisão de cirurgia plástica com neurofibroma plexiforme gigante no antebraço direito. Após ressecção cuidadosa, todos os tendões anteriores do antebraço foram expostos. O defeito foi coberto com Pelnac T enxertável (espessura de 3mm e tamanho 12 X 24cm2), fixados com pontos monocryl 4-0. Após 10 dias, a matriz dérmica acelular foi removida e um enxerto de malha de pele de espessura parcial foi colocado. No dia 7, a matriz dérmica acelular apresentou bons sinais de ingestão. No dia 17, observamos uma sobrevida do enxerto de 95%. No seguimento de 3 meses, a reconstrução estava estável, sem defeitos de contorno, a mão apresentava amplitude de movimento completa e o paciente não apresentava problemas nas atividades diárias. Conclusões: A matriz dérmica acelular parece ser uma opção útil na cobertura de defeitos complexos no antebraço, permitindo menor morbidade e rápida recuperação funcional.

Introduction: Giant plexiform neurinoma is a neuroectoderm and inherited disease. It is an uncommon skin tumor associated with NF1, characterized as a benign peripheral nerve sheath tumor surrounding multiple nervous fascicles. The goals of forearm coverage reconstruction are to protect the structures running to the wrist and hand and prevent scarring that leads to movement loss. Both forearm and hand play functional and social roles. Successful management of complex wounds is necessary for the overall functional rehabilitation of these patients. Case Report: A 31-year-old woman presented at the plastic surgery division with a giant plexiform neurofibroma in the right forearm. After careful resection, all anterior forearm tendons were exposed. The defect was covered with graftable Pelnac T (thickness of 3mm and sizing 12 X 24cm2), fixed with 4-0 monocryl sutures. After 10 days, the acellular dermal matrix silicone layer was removed, and a split-thickness skin meshed graft was placed. On day 7, the acellular dermal matrix showed good signs of intake. On day 17, we observed a 95% graft survival. At the 3-month follow-up, reconstruction was stable without contouring defects, the hand had full range of motion, and the patient had no problems in daily activities. Conclusions: Acellular dermal matrix appears to be a useful option in covering complex defects in the forearm, allowing for less morbidity and rapid functional recovery.

Efficacy comparison of bundle suture and Krackow suture in the treatment of acute closed Achilles tendon rupture / 中华创伤杂志

Objective:To compare the clinical efficacy of bundle suture and Krackow suture in the treatment of acute closed Achilles tendon rupture.Methods:A retrospective cohort study was used to analyze the clinical data of 58 patients with acute closed Achilles tendon rupture admitted to Tongji Hospital of Tongji University from August 2014 to August 2021, including 53 males and 5 females, aged 27-55 years [(39.6±7.1)years]. The patients were treated with open repair and were assigned to bundle suture group ( n=30) and Krackow suture group ( n=28). The incision length and operative time were compared between the two groups. The healing of the Achilles tendon was observed. The difference in circumference between the affected and healthy side of the calf, ratio of width to anterior-posterior diameter at the cross-sectional area of Achilles tendon rupture, and ratio of scar tissue to tendinous fibrous tissue at the cross-sectional area of Achilles tendon rupture were measured at 12 months after surgery. At the same time, the complete Achilles tendon rupture score (ATRS) and American Foot and Ankle Surgery Society (AOFAS) ankle-hindfoot score were performed. The occurrence of complications was observed at follow-up. Results:All patients were followed up for 12-28 months [(17.9±4.2)months]. The incision length and operative time in bundle suture group [6.0(4.5, 9.0)cm, 77.5(60.0, 95.0)minutes] were significantly shorter or longer than those in Krackow suture group [8.0(7.0, 11.0)cm, 68.5(55.0, 86.0)minutes] (all P<0.01). After 3 months, healing of the Achilles tendon was obtained in both groups. After 12 months, the difference in circumference between the affected and healthy side of the calf was (2.0±0.9)cm in bundle suture group and was (1.9±0.9)cm in Krackow suture group ( P>0.05); the ratio of width to anterior-posterior diameter at the cross-sectional area of Achilles tendon rupture was 1.42±0.20 in bundle suture group, significantly greater than 1.27±0.16 in Krackow suture group ( P<0.01); the ratio of scar tissue to tendinous fibrous tissue at the cross-sectional area of Achilles tendon rupture was 8.6%(6.0%, 24.0%) in bundle suture group, significantly lower than 11.9%(9.0%, 33.0%) in Krackow suture group ( P<0.01); the ATRS and AOFAS ankle-hindfoot score were 91.5(80.0, 99.0)points and 93.0(82.0, 100)points in bundle suture group, similar to 89.0(75.0, 99.0)points and 91.5(77.0, 99.0)points in Krackow suture group (all P>0.05). During the follow-up period, the occurrence of complications were not significantly different between bundle suture group [no deep infection, early Achilles tendon rerupture in 2 patients (7%) ] and Krackow suture group [deep infection in 1 patient (4%), early Achilles tendon rerupture in 1 patient (4%)] (all P>0.05). Conclusions:Both bundle suture and Krackow suture can achieve satisfactory clinical efficacy in the treatment of acute closed Achilles tendon rupture. However, the bundle suture is more conducive to restoring normal anatomical shape of the Achilles tendon and reducing scar formation at the end of the Achilles tendon rupture.

Research progress in the effect and mechanism of stem cell-derived exosomes in tendon and enthesis repair / 中华创伤杂志

Tendon and enthesis injuries are common sports injuries that seriously impair patients′ daily activities and quality of life. Surgical reconstruction is the main treatment for tendon and enthesis injuries. However, the surgical effect is often unsatisfactory due to the structure of repaired tendon and enthesis remaining different from those of the native ones, and re-rupture is prone to occur. Exosomes are lipid bilayer vesicles containing varieties of active substances, which play a crucial role in the communication of different cells. As a new cell-free therapy, stem cell-derived exosomes have been widely studied in the fields of drug delivery, tissue engineering and degenerative diseases, but their role in tendon and enthesis repair is rarely concerned. Therefore, the authors review tendon and enthesis injuries from aspects of histological features, repair process, and repair effect and mechanism of action of stem cells-derived exosomes, aiming to provide new insights into the basic research and clinical treatment of tendon and enthesis injuries.

Research progress in the diagnosis, treatment and rehabilitation of peroneal tendon spondylolisthesis / 中华创伤杂志

Peroneal tendon plays an important role in maintaining the alignment of the hindfoot and stabilizing the arch of the foot. It is also the main tendon against ankle varus injuries, and is of great significance in maintaining lateral ankle stability. As an infrequent disease, peroneal tendon spondylolisthesis can be easily misdiagnosed in clinical diagnosis and treatment which results in pain and instability of the lateral ankle and weakness in eversion of the affected foot. Improper diagnosis or treatment can affect patient quality of life. Peroneal tendon spondylolisthesis is mainly treated by non-surgical and surgical treatments, among which surgical treatments mainly include superior peroneal retinaculum repair, superior peroneal retinaculum augmentation, peroneal bone block procedure, peroneal groove deepening technique, and peroneal rearrangement. Surgical indications for different surgical treatments remain controversial. Moreover, there are no rehabilitation guidelines for peroneal tendon spondylolisthesis at home or abroad, and postoperative rehabilitation is generally based on the experience of clinicians. On the basis of related literature, the authors review the research progress in treating peroneal tendon spondylolisthesis from aspects of anatomical characteristics, injury mechanism, diagnosis, treatment and rehabilitation, so as to provide a reference for accurate and effective diagnosis, treatment and rehabilitation of peroneal tendon spondylolisthesis.

How useful is elastography in the follow-up of achilles tendon repair? / Quão útil é a elastografia no acompanhamento do reparo do tendão do calcâneo?

ABSTRACT Introduction: In addition to conservative modalities in the treatment of Achilles tendon injuries, open, percutaneous and minimally invasive semi-open techniques, as well as biological open surgical repair methods are used as surgical options. Compression elastography is one of the methods used for the follow-up of treatment in Achilles tendon injuries. Methods: 23 patients were included in our study between July 2013 and June 2014, as long as they had at least 4 years of follow-up. In the final control, the intact side and the operated side were both examined and compared. The variables were the American Orthopedic Foot and Ankle Score (AOFAS) which is measured as a functional score considering plantar flexion and dorsiflexion; calf circumference; Achilles tendon anteroposterior (AP) diameter; and elastographic examination. Results: The strain ratio value and AP diameter of the patients was significantly higher on the operated side than on the non-operated side (p <0.001). There was no significant difference between the plantar flexion and dorsiflexion degrees on the operated side of the patients(p> 0.05). No correlation was observed between strain ratio and AOFAS (p: 0,995). Conclusion: Elastography is not a useful technique to evaluate functional results on long-term tendon healing. Level of Evidence III; Retrospective comparative study.

RESUMO Introdução: Além de métodos mais conservadores de terapia, utilizam-se, como opções cirúrgicas para o tratamento das lesões do tendão do calcâneo, técnicas abertas, percutâneas e semiabertas minimamente invasivas, bem como métodos cirúrgicos de reparo aberto. A elastografia por compressão é um dos métodos utilizados para o acompanhamento do tratamento das lesões do tendão do calcâneo. Métodos: Entre julho de 2013 e junho de 2014, 23 pacientes com pelo menos 4 anos de seguimento foram incluídos em nosso estudo. No controle final, o lado intacto e o lado operado foram examinados e comparados. As variáveis foram o American Orthopaedic Foot and Ankle Score, que foi medido como pontuação funcional por meio da flexão plantar e dorsiflexão; a circunferência da panturrilha; o diâmetro anteroposterior (AP) do tendão do calcâneo; e exame elastográfico. Resultados: O índice de tensão e o diâmetro AP dos pacientes foram significativamente maiores no lado operado do paciente que no lado não operado. Não houve diferença significativa entre os graus de flexão plantar e dorsiflexão dos pacientes no lado operado (p> 0,05). Não foi observada correlação entre strain ratio e AOFAS(p: 0,995). Conclusão: Acreditamos que a elastografia não seja uma técnica útil para avaliar os resultados funcionais na cicatrização do tendão em longo prazo. Nível de evidência III; Estudo comparativo retrospectivo.

Rotura del tendón largo del bíceps braquial: resultado tras 15 años de evolución / Long tendon rupture of the biceps brachii: result after 15 years of evolution

RESUMEN 15. La rotura de la porción larga del tendón del bíceps produce dificultades para la función del miembro superior y la estética del brazo. Se presenta un paciente con rotura de tendón largo del bíceps, que fue tratado hace 15 años con tratamiento quirúrgico; se muestra desde su lesión y tratamiento hasta la recuperación total y sus condiciones actuales. El siguiente trabajo tiene como objetivo la presentación de un paciente, el cual fue atendido en el Hospital General Provincial Universitario «Mártires del 9 de Abril», en Sagua la Grande, por una rotura de la porción larga de bíceps en el año 2005. Se utilizó una forma de anclaje al hueso diferente a la clásica descrita en la literatura, con excelente resultado. Tras 15 años, se expone el caso y se detalla la evolución posterior, se valora la función actual y se aporta conocimiento interesante para los profesionales que tratan esta afección.

ABSTRACT 19. Rupture of the long head of the biceps tendon causes difficulties for upper limb function and arm aesthetics. We present a male patient with a rupture of the long biceps tendon, who was treated 15 years ago with surgical treatment; he is shown from his injury and treatment to his full recovery and current condition. The aim of the following work is to present a patient who was treated at "Mártires del 9 de Abril" Provincial General University Hospital, in Sagua la Grande, due to a rupture of the long head of the biceps in 2005. A form of bone anchorage, different from the classic one described in the literature, was used with excellent results. After 15 years, the case is presented and the subsequent evolution is detailed, the current function is assessed and interesting knowledge is provided for professionals who treat this condition.

Presión y área de contacto en reparación de manguito rotador: una revisión sistemática / Pressure and contact area in rotator cuff repair: a systematic review

OBJETIVO Proporcionar una sinopsis exhaustiva y un análisis de los estudios biomecánicos sobre la magnitud y distribución de la presión en la interfase tendón-huella de las roturas del manguito rotador, informadas en la literatura en los últimos cinco años. MÉTODOS La investigación se realizó de acuerdo con los métodos descritos en el Manual Cochrane. Los resultados se informan de acuerdo con el consenso de Ítems Preferidos de Reporte en Revisiones Sistemáticas y Metaanálisis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, en inglés). La búsqueda se realizó el 1er de junio de 2020. Se identificaron e incluyeron estudios ex vivo de ciencia básica y estudios biomecánicos publicados, que evaluaran la magnitud y distribución de la presión en la interfase tendón-huella de las roturas del manguito rotador reparadas entre enero de 2015 y junio de 2020. Se realizaron búsquedas sistemáticas en las bases de datos MEDLINE, Embase, Scopus y Google Scholar utilizando los términos y operadores booleanos: (Rotator Cuff OR Supraspinatus OR Infraspinatus OR Subscapularis OR Teres Minor) AND Pressure AND Footprint. En la base de datos Embase, respetando su sintaxis, se utilizó: Rotator Cuff AND Pressure AND Footprint. RESULTADOS Un total de 15 de los 87 artículos encontrados cumplieron con todos los criterios de elegibilidad y se incluyeron en el análisis. CONCLUSIÓN La presión y área de contacto sería optimizada biomecánicamente con una reparación transósea de doble fila equivalente, sin nudos en la hilera medial, y con el uso de cintas para su ejecución, conceptos de reparación específica para roturas delaminadas, y limitación de la abducción en el postoperatorio inmediato.

OBJETIVE To provide a comprehensive synopsis and analysis of biomechanical studies on the magnitude and distribution of pressure at the tendon-footprint interface of rotator cuff tears reported in the literature in the last five years. METHODS The research was performed according to the methods described in the Cochrane Manual. The results are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) consensus. The search was performed on June 1st, 2020. We identified and included ex vivo basic science studies and published biomechanical studies that evaluated the magnitude and distribution of pressure at the tendon-footprint interface of rotator cuff tears repaired between January 2015 and June 2020. Systematic searches on the MEDLINE, Embase, Scopus and Google Scholar databases were performed using the terms and Boolean operators: (Rotator Cuff OR Supraspinatus OR Infraspinatus OR Subscapularis OR Teres Minor) AND Pressure AND Footprint. In the Embase database, respecting its syntax, the following was used: Rotator Cuff AND Pressure AND Footprint. RESULTS In total, 15 of the 87 articles found fulfilled all the eligibility criteria and were included in the analysis. CONCLUSION The pressure and contact area would be biomechanically optimized with an equivalent transosseous double-row repair, without knots in the medial row, and with the use of tapes for its execution, specific repair concepts for delaminated tears, and a limitation of abduction in the immediate postoperative period.

Mayor presión y área de contacto en reparación transósea cruzada de manguito rotador versus reparación simple / Increased pressure and contact area in rotator cuff crossed versus simple transosseous repair

OBJETIVO: Comparar la presión y el área de contacto en la interfase tendón-huella de una reparación realizada con suturas transóseas simples y cruzadas. MÉTODOS: Se utilizaron doce hombros de cordero para simular una rotura de manguito rotador. Se midió el área de contacto en la interfase tendón-huella con láminas sensibles a presión; luego, se midió la presión con un sensor digital. Se registró la presión basal durante la aplicación de carga cíclica y al final de la intervención. Se compararon 2 reparaciones: 2 túneles transóseos con nudos simples (TOS; n = 6) y 2 túneles transóseos con nudos cruzados (TOC; n = 6), utilizando FiberWire #2. Se realizaron 1.400 ciclos, con una frecuencia 2,5 Hz y una carga de 5 N. Se utilizó la prueba de Mann-Whitney, y ae consideraron significativos valores de p < 0,05. RESULTADOS: La reparación TOS presentó un 50,9 ± 12,7% distribución de presiones en comparación con 72,2 ± 5,3% en la reparación TOC (p < 0,009). La presión promedio en la reparación TOS fue 0,7 ± 0,1 MPa en comparación con 1,1 ± 0,2 MPa en la reparación TOC (p < 0,007). La reparación TOS registró una presión basal de 5,3 ± 5,3 N, presión final de 3,8 ± 4,6 N, y una variación de 51,7 ± 38%. La reparación TOC registró una presión basal de 10,7 ± 1,8 N, presión final de 12,9 ± 8,7 N, y una variación de 114,9 ± 65,9% (p < 0,044; p < 0,022; y p < 0,017, respectivamente). CONCLUSIÓN: La reparación TOC presenta mayor presión a nivel de la interfase tendón-hueso, menor pérdida de fuerza de contacto ante cargas cíclicas, y una mejor distribución de fuerza en la huella al comparar con la reparación TOS, lo que se podría traducir en mejor cicatrización tendínea.

OBJETIVE: To compare the pressure and contact area at the tendon-footprint interface of a repair performed with simple and crossed transosseous sutures. METHODS: Twelve lamb shoulders were used to simulate a rotator cuff tear. The contact area at the tendon-footprint interface was measured with pressure-sensitive films; then, the pressure was measured with a digital sensor. The baseline pressure was recorded during the application of a cyclic load and at the end of the intervention. A total of 2 repairs were compared: 2 transosseous sutures with single knots (STO; n = 6) and 2 transosseous sutures with crossed knots (TOC; n = 6) using FiberWire #2. In total, 1,400 cycles were performed, with a frequency of 2.5 Hz and a load of 5 N. The Mann-Whitney test was used. Values of p < 0.05 were considered significant.RESULTS: The TOS repair presented 50.9 ± 12.7% of pressure distribution compared to 72.2 ± 5.3% in the TOC repair (p < 0.009). The mean pressure in the TOS repair was of 0.7 ± 0.1 MPa compared to 1.1 ± 0.2 MPa in the TOC repair (p < 0.007). The TOS repair registered a basal pressure of 5.3 ± 5.3 N, a final pressure of 3.8 ± 4.6 N, and a variation of 51.7 ± 38%. The TOC repair registered a basal pressure of 10.7 ± 1.8 N, a final pressure of 12.9 ± 8.7 N, and a variation of 114.9 ± 65.9% (p < 0.044; p < 0.022; and p < 0.017 respectively).CONCLUSION: The TOC repair presents higher pressure at the tendon-bone interface, less loss of contact force under cyclic loads, and a better distribution of force on the footprint when compared with the TOS repair, which could translate into better tendon healing.

Abrasión intraósea por sutura según el ángulo del túnel transóseo en huella del manguito rotador / Intraosseous suture abrasion according to the angle of the transosseous tunnel in rotator cuff footprint

OBJETIVO: Comparar el desgaste óseo generado por la abrasión de una carga cíclica entre túneles clásicos oblicuos y perpendiculares. Nuestra hipótesis es la de que el túnel oblicuo presenta un menor desgaste óseo por abrasión cíclica comparado con el túnel perpendicular. MÉTODOS: Ocho hombros congelados de cordero fueron usados para el estudio biomecánico. En cada húmero proximal, dos túneles (oblicuo y perpendicular) fueron generados en la tuberosidad mayor. Se utilizó un sistema de tracción cíclica para traccionar hacia atrás y adelante una sutura trenzada en tensión a través del túnel, midiendo la distancia entre la entrada y la salida de la sutura en el túnel antes y después del proceso de ciclado como medida de perdida de tensión de la sutura. El resultado principal es el cambio de la distancia entre la entrada y la salida de la sutura en el túnel después del ciclado para estimar el desgaste óseo dentro del túnel. Para el análisis estadístico, se utilizó la prueba U de Mann-Whitney. Se consideraron significativos valores de p < 0,05. RESULTADOS: Los túneles perpendiculares tuvieron un 23,24 7,44% de pérdida de longitud, y los túneles oblicuos, 7,76 4,32%. La diferencia de pérdida de longitud fue significativa (p » 0,0003). CONCLUSIÓN: La abrasión ósea generada por el movimiento cíclico de la sutura en el túnel transóseo está influenciada por la geometría del túnel. El desgaste óseo es menor en un túnel oblicuo comparado con un túnel perpendicular. NIVEL DE EVIDENCIA: Estudio de ciencia básica

OBJETIVE: To compare the bone wear generated by the abrasion of a cyclic load between classic oblique and perpendicular tunnels. Our hypothesis is that the oblique tunnel is submitted to less cyclic abrasion bone wear compared with the perpendicular tunnel. METHODS: Eight fresh-frozen lamb shoulders were used for biomechanical testing. In each proximal humerus, two tunnels (one oblique and one perpendicular) were drilled at the greater tuberosity. We used a cyclic traction system to pull back and forth a braided suture under tension through the tunnel, measuring the distance between the entry and exit points of the suture within the tunnel before and after the cyclic process to release the tension in the suture. The main outcome was the percentage of change in the distance between the entry and exit points of the suture within the tunnel before and after cyclic abrasion to estimate the degree of bone wear inside the tunnel. For the statistical analysis, the Mann-Whitney U test was used. Values of p < 0.05 were considered significant. RESULTS: The perpendicular bone tunnels had 23.24 7.44% decrease in length, and the oblique bone tunnels, 7.76 4.32%. The difference in the decrease in length was significant (p » 0.0003). CONCLUSION: The bone abrasion caused by the cyclical movement of the suture in the bone tunnel was influenced by the shape of the tunnel. Bone wear was lower with an oblique tunnel compared with a perpendicular tunnel. LEVEL OF EVIDENCE: Basic Science Study

Avulsão do tendão reto femoral em atleta amador: relato de caso diagnosticado pela ressonância magnética / Rectus femoris tendon avulsion in an amateur athlete: case report diagnosed by magnetic resonance

Introdução: o músculo reto femoral é o músculo mais frequentemente lesado do grupo quadríceps durante chutes e corridas repetitivas, apesar de suas avulsões serem raras. A dor localizada na coxa proximal e a incapacidade de flexionar o quadril e/ou estender o joelho associado à história do paciente de contração violenta ou alongamento forçado do grupo muscular do quadríceps femoral podem indicar uma avulsão do reto femoral. Objetivo: relatar um caso e revisar a literatura acerca desta lesão incomum. Materiais e Métodos: revisão do prontuário, registro fotográfico do método diagnóstico e revisão da literatura. Resultados: homem de 46 anos com dor localizada no quadril esquerdo com irradiação para a coxa por três meses após cair no chão com a região dolorida em um jogo de futebol. A dor começou subitamente uma semana após a queda. A ressonância magnética do quadril apresentava avulsão completa do reto femoral esquerdo, distando 2 cm da espinha ilíaca anterior inferior com efusão líquida adjacente. Conclusão: este relato demonstra a dificuldade de diagnosticar essa lesão, pois o seu exame físico é inespecífico, podendo simular patologias mais complexas, necessitando de exames complementares para seu correto diagnóstico.

Introduction: the rectus femoris muscle is the most frequently injured muscle of the quadriceps group during repetitive kicking and sprinting. Avulsions of the rectus femoris are rare injuries. Pain located at the proximal thigh and disability in flexing the hip and/or extending the knee associated with a patient history of a violent contraction or forceful stretching of the quadriceps femoris muscle group can indicate an avulsion of rectus femoris. Objective: report a case and review the literature about this uncommon lesion. Materials and Methods: we reviewed medical records, photographic records of diagnostic methods, and reviews from the literature. Results: a 46-year-old man with pain located at the left anterior hip with irradiation to the thigh for three months after falling to the ground with the sore region in a soccer game. The pain started suddenly one week after the fall. The MRI of the hip featured complete avulsion of the left rectus femoris, being 2 cm distal from the anterior inferior iliac spine with adjacent liquid effusion. Conclusion: this report demonstrates the difficulty of diagnosing this lesion, since its physical examination is non-specific, and it can simulate more complex pathologies, requiring complementary tests for its correct diagnosis.

Presión en la reparación de manguito rotador con suturas transóseas y Mason-Allen modificado / Pressure on the rotator cuff repair with transosseous sutures and modified Mason-Allen

OBJETIVO:Comparar el promedio de curva de presión de contacto y el porcentaje de presión de contacto residual final en la interfase tendón-huella de una reparación transósea (TO) realizada con nudos cruzados y una configuración Mason-Allen modificada (MAM). MÉTODOS: Se utilizaron ocho hombros de cordero para simular una rotura de manguito rotador. Se midió la presión con un sensor digital. Se registró la presión basal durante la aplicación de carga cíclica y al final de la intervención. Se compararon dos reparaciones: dos túneles TOs con nudos cruzados (TOCs) (n » 4) y dos puntos MAMs (n » 4) utilizando suturas MaxBraid #2 (Zimmer Biomet, Warsaw, IN, EEUU). Se realizaron 1.000 ciclos, con una frecuencia de 2 Hz y una carga de 30 N. Se utilizó el test de t de Student, y se consideraron significativos valores de p < 0,05. RESULTADOS: El promedio de curva de presión de contacto en las piezas que fueron reparadas con suturas TOCs fue de 86,01 8,43%, mientras que con MAM fue de 73,28 12,01% (p < 0,0004). El promedio del porcentaje residual al final del ciclado fue de 71,57% para suturas TOCs y de 51,19% para MAM (p < 0,05). CONCLUSION: La reparación TOC presenta mayor promedio de curva de presión de contacto y mayor porcentaje de presión de contacto residual final en la interfase tendón-huella que la reparación con sutura MAM luego de carga cíclica estandarizada, lo que podría traducirse en una mejor cicatrización del tendón. NIVEL DE EVIDENCIA: Estudio de ciencia básica.

OBJECTIVE: To compare the average contact pressure curve and the percentage of final residual contact pressure at the tendon-footprint interphase of a transosseous (TO) repair performed with crossover sutures or a modified Mason-Allen (MMA) configuration. METHODS: Eight lamb shoulders were used to simulate a rotator cuff tear. The pressure was measured with a digital sensor. The baseline pressure was recorded during the application of the cyclic load and at the end of the intervention. Two repairs were compared: 2 crossover TO (CTO) sutures (n » 4) and 2 MMA sutures MMA (n » 4), using MaxBraid #2 (Zimmer Biomet, Warsaw, IN, US) sutures. A thousand cycles were performed, with a frequency of 2 Hz and a 30-N load. The Student t-test was used, and significance was set at p < 0.05. RESULTS: The average contact pressure curve was of 86.01 8.43% for parts repaired with CTO sutures, and of 73.28 12.01% for those repaired with MMA sutures (p < 0.0004). The mean residual percentage at the end of cycling was of 71.57% for CTO sutures, and of 51.19% for MMA sutures (p < 0.05). CONCLUSION: The CTO repair shows a higher average contact pressure curve and a higher percentage of final residual contact pressure at the tendon-footprint interphase than the MMA suture repair after standardized cyclic loading, potentially resulting in improved tendon healing. LEVEL OF EVIDENCE: Basic Science Study.