Hip joint contact pressure and force: a scoping review of in vivo and cadaver studies.

Aims: Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters. Methods: We used the PRISMA extension for scoping reviews for this literature search in three databases. After screening, 16 studies were included for the final analysis. Results: The studies assessed different hip conditions like labrum status, the biomechanical effect of the cam, femoral version, acetabular coverage, and the effect of rim trimming. The testing and loading conditions were also quite diverse, and this disparity limits direct comparisons between the different researches. With normal anatomy the mean contact pressures ranged from 1.54 to 4.4 MPa, and the average peak contact pressures ranged from 2 to 9.3 MPa. Labral tear or resection showed an increase in contact pressures that diminished after repair or reconstruction of the labrum. Complete cam resection also decreased the contact pressure, and acetabular rim resection of 6 mm increased the contact pressure at the acetabular base. Conclusion: To date there is no standardized methodology to access hip contact biomechanics in hip arthroscopy, or with the preservation of the periarticular soft-tissues. A tendency towards improved biomechanics (lower contact pressures) was seen with labral repair and reconstruction techniques as well as with cam correction.

Transiliac Endoscopic-Assisted L5S1 Intraforaminal Lumbar Interbody Fusion: Technical Considerations and Potential Complications.

OBJECTIVE: We sought to determine the clinical outcomes, complications, and fusion rates in transiliac endoscopic-assisted L5S1 intraforaminal lumbar interbody fusion (iLIF). METHODS: Between September 2020 and September 2021, patients with L5S1 degenerative disk disease were enrolled in a prospective study on transiliac L5S1 iLIF and followed for a minimum of 12 months. Conflict of the preoperative planned approach with the ilium was mandatory. The primary outcome measures were the Oswestry Disability Index, the visual analog scale (VAS) score for low back pain (VAS back) and leg pain (VAS leg), and the modified MacNab criteria. The secondary outcomes were complications and fusion rates. RESULTS: Five consecutive patients were enrolled: 2 males and 3 females with a mean age of 50 ± 12.9. All had 12 months' follow-up. The mean improvement in the Oswestry Disability Index, VAS back, and VAS leg (44 ± 11.75, 6.6 ± 1.7, and 4.7 ± 4.2, respectively) was more than 3 times the minimum clinically important difference. The modified MacNab criteria were good or excellent in 80% of cases at all endpoints. Three patients had ipsilateral lower limb dysesthesia. One patient had revision surgery for foraminal bone fragment removal. All patients achieved fusion. CONCLUSIONS: The transiliac iLIF is a feasible but demanding surgical technique that allows overcoming cases in which the ilium prevents endoscopic transforaminal access to L5S1. Our preliminary results had good clinical outcomes and high fusion rates. The main complication was late-onset dysesthesia of the ipsilateral lower limb, 10 to 14 days after surgery. Special care must be taken to prevent L5 dorsal root ganglion injury.

Transforaminal Endoscopic Approach to L5S1: Imaging Characterization of the Lower Lumbar Spine and Pelvis for Surgical Planning.

OBJECTIVE: To determine and compare pelvic and lumbosacral reference parameters with computed tomography in patients with low back pain (LBP) and a control group of asymptomatic patients to provide quantification data and morphological correlations for L5S1 transforaminal endoscopic approach (L5S1TEA). METHODS: We prospectively evaluated 100 patients with LBP and a control group of 100 individuals, with spinopelvic computed tomography. We measured lumbopelvic and L5S1 transforaminal approach parameters: maximum approach angle (maxAA) and minimum approach angle (minAA) and skin incision (maxSI and minSI), iliac crest (IC) projection at intersection point (ICPi), distance between the projected intersection of maxAA with the ilium (ICi) and the posterior limit of the IC (ΔICi-ICpost), and distance between ICi and spinous process (ΔICi-SP). RESULTS: Females and ICPi were increased in the LBP group: maxAA: 48.38° ± 5.09°; minAA:32.5° ± 3.90°; maxSI: 11.39 ± 1.86 cm; and minSI: 8.30 ± 1.48 cm. Ilium intersection was increased in males; IC projection at the highest point (ICPh) was higher than ICPi; maxAA intersected the ilium in 28% and minAA in 1.5% of cases; ICi was positively correlated with facet angle, ICPh, and ICPi and negatively with ΔICi-SP. CONCLUSIONS: Our results set preliminary reference values for L5S1TEA surgical planning. Besides higher ICPi, there were no differences between groups in measured parameters. Traditional IC height (ICPh) does not correspond to the point of intersection of the approach and is significantly higher than ICPi. ICi correlated to higher facet angle values, ICPh and ICPi grades, and lower ΔICi-SP. Potential conflict with the ilium is increased in the male population. IC is not impeditive of L5S1TEA in most cases.

[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.

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.

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.