16 research outputs found
Meniscus subluxation retensioning: “autotransplant”
Knee osteoarthritis (OA) is a common condition in the older population and is characterized by several articular dysfunctions with consequent anatomic abnormalities including osteochondral degenerative changes and meniscal extrusion. Meniscal damage with extrusion is one of the strongest identified risk factors for the development and progression of knee OA and represents an important factor in the long-term health of the joint. Meniscal extrusion can alter normal knee biomechanics and dramatically inhibit meniscal function. We present a surgical technique for the treatment of early knee OA in association with an extruded meniscus to restore the meniscal anatomic position and preserve its native physiological function related to cartilage preservation. Meniscal retensioning, or a "meniscal autotransplant," can increase meniscal coverage in the compromised compartment, prevent cartilage degeneration, decrease subchondral bone exposure, and restore the compartmental space and, consequently, can relieve patients' symptoms related to early OA.The experimental work (arthroscopy laboratory) and surgical equipment were financially supported by Arthrex. Video 1 was edited by Arthrex. J.E-M. received support for travel-related expenses and laboratory equipment from Arthrex for this study. R.B. received support for travel-related expenses and laboratory equipment from Arthrex for this study. Full ICMJE author disclosure forms are available for this article online, as supplementary material
Animal model for chronic massive rotator cuff tear: behavioural and histologic analysis
Purpose
Massive rotator cuff tears (MRCT) are usually chronic lesions that present associated degenerative changes of the myotendinous unit that have been implicated in limitations for surgical repair. In order to develop effective therapies, it is important to establish animal models that mimic the hallmarks of the injury itself. Therefore, in the present work, we aimed to (1) optimize a rodent animal model of MRCT that closely reproduces the fatty infiltration of the cuff muscles seen in humans and (2) describe the effects of unilateral or bilateral lesion in terms of histology and behaviour.
Methods
Massive tear was defined as two rotator cuff tendons—supraspinatus and infraspinatus—section. Twenty-one Wistar rats were randomly assigned to four groups: bilateral lesion (five animals), right-sided unilateral lesion (five animals), left-sided unilateral lesion (five animals) and control (six animals). Behaviour was analyzed with open field and staircase test, 16 weeks after lesion. After that, animals were killed, and the supraspinatus and infraspinatus muscles were processed.
Results
Histologic analysis revealed adipocytes, fatty infiltration and atrophy in the injured side with a greater consistency of these degenerative changes in the bilateral lesion group. Behaviour analysis revealed a significant functional impairment of the fine motor control of the forepaw analyzed in staircase test where the number of eaten pellets was significantly higher in sham animals (sham = 7 ± 5.0; left unilateral = 2.6 ± 3.0; right unilateral = 0 ± 0; and bilateral = 0 ± 0, p left unilateral = 2 ± 2.1 > right unilateral = 0.8 ± 1.3 > bilateral = 0.8 ± 1.1).
Conclusions
The present study has been able to establish an animal model that disclosed the hallmarks of MRCT. This can now be used as a valuable, cost-effective, pre-clinical instrument to assist in the development of advanced tissue engineered strategies. Moreover, this animal model overcomes some of the limitations of those that have been reported so far and thus represents a more reliable source for the assessment of future therapeutic strategies with potential clinical relevance.Portuguese Foundation for Science and Technology (FCT)Programa Operacional Regional do Norte (ON.2—O Novo Norte), ao abrigo do Quadro de Referência Estratégico Nacional (QREN), através do Fundo Europeu de Desenvolvimento Regional (FEDER
Assessment of rotatory laxity in anterior cruciate ligament-deficient knees using magnetic resonance imaging with Porto-knee testing device
Purpose Objective evaluation of both antero-posterior
translation and rotatory laxity of the knee remains a target
to be accomplished. This is true for both preoperative
planning and postoperative assessment of different ACL
reconstruction emerging techniques. The ideal measurement tool should be simple, accurate and reproducible,
while enabling to assess both ‘‘anatomy’’ and ‘‘function’’
during the same examination. The purpose of this study is
to evaluate the clinical effectiveness of a new in-housedeveloped testing device, the so-called Porto-knee testing
device (PKTD). The PKTD is aimed to be used on the
evaluation of both antero-posterior and rotatory laxity of
the knee during MRI exams.
Methods Between 2008 and 2010, 33 patients with ACLdeficient knees were enrolled for the purpose of this study.
All patients were evaluated in the office and under
anesthesia with Lachman test, lateral pivot-shift test and
anterior drawer test. All cases were studied preoperatively
with KT-1000 and MRI with PKTD, and examinations
performed by independent observers blinded for clinical
evaluation. During MRI, we have used a PKTD that applies
antero-posterior translation and permits free tibial rotation
through a standardized pressure (46.7 kPa) in the proximal
posterior region of the leg. Measurements were taken for
both knees and comparing side-to-side. Five patients with
partial ruptures were excluded from the group of 33.
Results For the 28 remaining patients, 3 women and 25
men, with mean age of 33.4 ± 9.4 years, 13 left and 15 right
knees were tested. No significant correlation was noticed for
Lachman test and PKTD results (n.s.). Pivot-shift had a
strong positive correlation with the difference in anterior
translation registered in lateral and medial tibia plateaus of
injured knees (cor. coefficient = 0.80; p\0.05), and with
the difference in this parameter as compared to side-to-side
(cor. coefficient = 0.83; p\0.05).
Considering the KT-1000 difference between injured and
healthy knees, a very strong positive correlation was found
for side-to-side difference in medial (cor. coeffi-
cient = 0.73; p\0.05) and lateral (cor. coefficient = 0.5;
p\0.05) tibial plateau displacement using PKTD.
Conclusion The PKTD proved to be a reliable tool in
assessment of antero-posterior translation (comparing with
KT-1000) and rotatory laxity (compared with lateral pivotshift under anesthesia) of the ACL-deficient knee during
MRI examinatio
Osteochondral transplantation using autografts from the upper tibio-fibular joint for the treatment of knee cartilage lesions
Purpose Treatment of large cartilage lesions of the knee
in weight-bearing areas is still a controversy and challenging topic. Autologous osteochondral mosaicplasty has
proven to be a valid option for treatment but donor site
morbidity with most frequently used autografts remains a
source of concern. This study aims to assess clinical results
and safety profile of autologous osteochondral graft from
the upper tibio-fibular joint applied to reconstruct symptomatic osteochondral lesions of the knee.
Methods Thirty-one patients (22 men and 9 women) with
grade 4 cartilage lesions in the knee were operated by
mosaicplasty technique using autologous osteochondral
graft from the upper tibio-fibular joint, between 1998 and
2006. Clinical assessment included visual analog scale
(VAS) for pain and Lysholm score. All patients were
evaluated by MRI pre- and post-operatively regarding joint
congruency as good, fair (inferior to 1 mm incongruence),
and poor (incongruence higher than 1 mm registered in any
frame). Donor zone status was evaluated according to
specific protocol considering upper tibio-fibular joint
instability, pain, neurological complications, lateral collateral ligament insufficiency, or ankle complaints.
Results Mean age at surgery was 30.1 years (SD 12.2). In
respect to lesion sites, 22 were located in weight-bearing
area of medial femoral condyle, 7 in lateral femoral condyle, 1 in trochlea, and 1 in patella. Mean follow-up was
110.1 months (SD 23.2). Mean area of lesion was 3.3 cm
2
(SD 1.7), and a variable number of cylinders were used,
mean 2.5 (SD 1.3). Mean VAS score improved from 47.1
(SD 10.1) to 20.0 (SD 11.5); p = 0.00. Similarly, mean
Lysholm score increased from 45.7 (SD 4.5) to 85.3
(SD 7.0); p = 0.00. The level of patient satisfaction was
evaluated, and 28 patients declared to be satisfied/very
satisfied and would do surgery again, while 3 declared as
unsatisfied with the procedure and would not submit to
surgery again. These three patients had lower clinical scores
and kept complaints related to the original problem but
unrelated to donor zone. MRI score significantly improved
at 18–24 months comparing with pre-operative (p = 0.004).
No radiographic or clinical complications related to donor
zone with implication in activity were registered.
Conclusions This work corroborates that mosaicplasty
technique using autologous osteochondral graft from the
upper tibio-fibular joint is effective to treat osteochondral
defects in the knee joint. No relevant complications related
to donor zone were registered
Roturas massivas da coifa dos rotadores: uma abordagem biológica e regenerativa
Tese de Doutoramento em MedicinaMassive rotator cuff tears (MRCTs) are very large tears that are difficult to repair and often
associated to an uncertain prognosis. These lesions are usually degenerative and may be
associated with chronic pain and severe functional impairments. They are extremely frequent
with advancing age, leading to great suffering and limitations in affected patients. The
musculo-tendinous degenerative changes associated to chronic MRCTs and, the low natural
healing and regeneration potential of the rotator cuff Tendon-Bone interface (TBi) represents a
difficult challenge, thereby imposing the development of new therapeutic strategies. Several
clinical solutions (e.g. surgical repair, tendon transfers, reverse shoulder arthroplasty and,
superior capsule reconstruction) have been addressed to tackle this problem. However, none of
them have been, so far, satisfactory, imposing the need for innovative therapeutical
approaches.
Several studies have proposed the use of stem cells as a possible tool for tendon healing and
regeneration, and within it, human mesenchymal stem cells (hMSCs) have emerged as a valid
therapeutic option. Most of their therapeutic effects are attributed to their capacity of secreting
a wide panel of trophic factors (secretome) capable of inducing modulation and regenerative
processes in the affected regions. Having this in mind the present thesis aimed at developing
innovative strategies for MRCT regenerative medicine based on hMSCs, their secretome and
the combination of them with nanopatterned based biodegradable biomaterials.
For this purpose a MRCT rat model was initially established by sectioning bilaterally the
supraspinatus and infraspinatus tendons. Interestingly, with the use of a bilateral lesion, our
results demonstrated that the degenerative changes were aggravated in a more accurate way,
resembling those observed in human tissues. Consequently, the described animal model
represented a key step for the assessment of therapeutic strategies aiming at
preventing/reverting chronic musculo-tendinous changes and/or enhancing the potential
healing of TBi.
After this, considering the importance of muscle quality on TBi healing and surgical outcomes when repair is attempted, the effect of hMSCs secretome on the prevention of muscle
degeneration after inflicting a MRCT was analyzed. It was observed that the injection of
hMSCs secretome immediately after the lesion was established, could decrease the
development of muscle degeneration in a rodent model of MRCT. In addition, both precise
intramuscular local injection and multiple systemic secretome injections shown to be
promising delivery forms for preventing muscle degeneration. This strategy is particularly
important for patients whose tendon healing after later surgical repair could be compromised
by the progressing degenerative changes.
Finally, the impact of a Tissue Engineering (TE) strategy based on the combination of an
electrospun keratin scaffold seeded with hMSCs secretome-preconditioned human tendon
cells (hTCs) to improve rotator cuff TBi healing, without surgical repair, was assessed. Initial
in vitro data revealed that hMSCs secretome increased hTCs phenotype, particularly the
expression of extracellular matrix associated molecules, as well as their cell densities, and
viability. A proteomic characterization of hMSCs secretome, revealed the presence of specific
proteins (e.g. Follistatin, Pigment epithelium-derived factor (PEDF), IL-6, decorin, and
biglycan) involved in muscle homeostasis and TBi healing, which are most likely linked to
these phenomena. Subsequent experiments performed in a MRCT rat animal model
(previously described and discussed) revealed that preconditioning hTCs with the hMSCs
secretome in a TE strategy yielded improved rotator cuff TBi healing.
In summary, the present work indicates that hMSCs, and their secretome, could represent a
potential tool to help treating and improve MRCT outcomes. Nevertheless, we should keep in
mind that its application in the future should be combined with other different approaches,
particularly those that use TE concepts. These findings are of clinical and social relevance as
they bring a new perspective for the prevention and treatment of MRCT aiming to improve the
quality of life of these patients.As roturas massivas da coifa dos rotadores (RMCR) são roturas grandes, difíceis de reparar e
muitas vezes associadas a um prognóstico incerto. Estas lesões são geralmente degenerativas e
podem causar dor crónica e incapacidade funcional graves. As RMCR são mais frequentes
com o avançar da idade, levando a um aumento da sintomatologia e limitação funcional. As
alterações degenerativas músculo-tendinosas associadas às RMCR crónicas e o baixo
potencial natural de cicatrização e regeneração da interface Osso-Tendão (iOT) da coifa dos
rotadores representam um desafio difícil, impondo assim o desenvolvimento de novas
estratégias terapêuticas. Várias soluções clínicas (e.g. reparação cirúrgica, transferências
tendinosas, artroplastia invertida do ombro e reconstrução da cápsula superior) têm sido
usadas para tentar resolver este problema. No entanto, nenhuma destas opções tem sido
satisfatória, até agora, impondo a necessidade de terapêuticas inovadoras.
Vários estudos têm proposto o uso de células-estaminais como uma possível ferramenta para a
cicatrização e regeneração do tendão e, dentro destas, as células-estaminais mesenquimatosas
humanas (CEMh) emergiram como uma opção terapêutica válida. A maior parte dos seus
efeitos terapêuticos é atribuída à sua capacidade de segregar um vasto painel de fatores
tróficos (secretoma) que são capazes de induzir modulação e processos regenerativos nas
regiões afetadas. Tendo isto em mente, a presente tese teve como objetivos o desenvolvimento
de estratégias inovadoras para a medicina regenerativa das RMCR baseada em CEMh, o seu
secretoma e a combinação deles com biomateriais biodegradáveis baseados em nanopartículas.
Para este propósito, um modelo de rato de RMCR foi inicialmente estabelecido através da
secção bilateral dos tendões supra-espinhoso e infra-espinhoso. Curiosamente, os nossos
resultados demonstraram que usando a lesão bilateral, as alterações degenerativas foram
agravadas de forma mais consistente e semelhante aquelas observadas nos tecidos humanos.
Consequentemente, o modelo animal descrito representou um passo chave para a avaliação de
estratégias terapêuticas visando a prevenção/reversão de alterações músculo-tendinosas
crónicas e/ou o aumento do potencial de cicatrização da iOT. Depois disso, e considerando a importância da qualidade do músculo na cicatrização da iOT e
dos resultados cirúrgicos quando a reparação é tentada, foi analisado o efeito do secretoma das
CEMh sobre a prevenção de degeneração muscular após induzir uma RMCR. Os resultados
demonstraram que a injeção de secretoma das CEMh, imediatamente após a lesão ser
estabelecida, poderia diminuir o desenvolvimento de degeneração muscular num modelo de
rato de RMCR. Além disso, tanto a injeção local precisa intramuscular quanto as injeções
sistémicas múltiplas de secretoma mostraram ser formas de administração promissoras para
prevenir a degeneração muscular. Esta estratégia é particularmente importante para os
pacientes cuja cicatrização do tendão após a posterior reparação cirúrgica poderia ser
comprometida pelas alterações degenerativas progressivas.
Por fim, avaliou-se o impacto de uma estratégia de Engenharia de Tecidos (ET) baseada na
combinação de uma matriz de queratina electroalinhada semeada com células tendinosas
humanas (CTh) pré-condicionadas pelo secretoma das CEMh para melhorar a cicatrização da
iOT da coifa dos rotadores, sem reparação cirúrgica associada. Os dados iniciais in vitro
revelaram que o secretoma das CEMh aumentaram o fenótipo das CTh, particularmente a
expressão de moléculas associadas à matriz extracelular, bem como a sua viabilidade e
densidades celulares. A caracterização proteómica do secretoma das CEMh, revelou a
presença de proteínas específicas (e.g. Follistatina, fator derivado do epitélio pigmentado
(FDEP); IL-6, decorina, and biglycano) envolvidos na homeostasia muscular e cicatrização da
iOT, e que estão muito provavelmente ligados a estas ações. Experiências subsequentes
realizadas no modelo animal de rato de RMCR (anteriormente descrito e discutido) revelaram
que o pré-condicionamento de CTh com o secretoma das CEMh, numa estratégia de ET,
proporcionou uma melhoria da cicatrização da iOT da coifa dos rotadores.
Em resumo, o presente trabalho indica que as CEMh, e o seu secretoma, podem representar
um instrumento potencial para ajudar a tratar e melhorar os resultados clínicos das RMCR. No
entanto, devemos ter em mente que a sua aplicação futura deve ser combinada com outras
abordagens diferentes, particularmente aquelas que utilizam conceitos de ET. Estes achados
são de relevância clínica e social, uma vez que trazem uma nova perspetiva para a prevenção e
tratamento das RMCR visando melhorar a qualidade de vida desses pacientes.The work presented in this thesis was performed in the Life and Health Sciences Research Institute (ICVS), Minho University. Financial support was provided by FEDER funds through the Operational Programme Competitiveness Factors - COMPETE and National Funds through FCT - Foundation for Science and Technology under the project POCI-01-0145-FEDER-007038; and by the project NORTE-01-0145-FEDER-
000013, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF)
Complex Elbow Dislocations
Complex Elbow DislocationsSports practice has become common in all ages, and the number of persons practicing extreme sports has been rapidly increasing. High-risk activities have raised the number and severity of (elbow) lesions that can cause severe disability.
Diagnosis of acute elbow dislocation is usually clinically evident, and reduction should be performed expeditiously. On-field reduction should be performed if an experienced health technician is present. Most of the times, the radiographic evaluation is performed first and usually allows identifying an associated fracture that defines a complex dislocation. Postreduction radiographic control is essential, and frequently CT scan or MRI can complete the information needed to fully understand the lesion and plan the treatment.
Fractures associated with elbow dislocation are frequent, but fortunately most of them are impacted fractures that do not require surgical treatment. When the dislocation causes a fracture of the olecranon, the radial head, and/or the coronoid, this can justify surgical treatment to provide stability and allow for early rehabilitation in an attempt to avoid either the stiffness or the instability.
The most frequent patterns of complex dislocation needing surgical treatment are transolecranon fracture-dislocations and elbow dislocations associated with fracture of the coronoid and/or the radial head. When both coronoid and radial head fractures are present, this pattern of injury is known as “elbow terrible triad” due to the bad outcomes associated with treatment.
Surgical treatment can include open reduction and internal fixation of the fractures, exploration, and repair of the medial collateral ligament and/or the lateral ulnar collateral ligament. Dynamic external fixation is another useful option when the elbow remains unstable even after surgical treatment, allowing an early mobilization while maintaining a concentric and stable reduction. Its use needs a strict technique to avoid possible complications such as radial nerve palsy.
In summary, ensuring a stable elbow that allows an early active range of motion is the critical point to improve elbow function after a complex elbow dislocation.(undefined)info:eu-repo/semantics/publishedVersio
Improved outcomes of older patients with acute and displaced proximal humerus fractures treated with window bone ingrowth fracture-specific stem reverse shoulder arthroplasty
Abstract Background The optimal treatment of displaced proximal humerus fractures (PHFs) in the older people population remains controversial. Reverse shoulder arthroplasty (RSA) is a popular surgical treatment option that provides improved and reproducible results. However, the relevance of fracture-specific stem designs for RSA to improve tuberosity consolidation and shoulder function remains debatable. Methods This study included all patients 70 years or older with acute and displaced PHFs primarily treated with RSA at a single institution in Portugal, between January 2010 and December 2019 who participated in a minimum follow-up of 2 years. Results A total of 112 patients (15 men and 97 women) with a median clinical follow-up of 52 months were included. The mean age at the time of fracture was 78.6 years. All fractures were classified as Neer types 3 and 4 (n = 50 and n = 62, respectively). A window bone ingrowth fracture-specific stem was used for 86 patients, and a conventional humeral stem was used for 26 patients. Regarding the tuberosity fixation technique, 76 tuberosities were attached using technique A (according to Boileau's principles), 36 tuberosities were attached using technique B (not following Boileau's principles) and 11cases were classified as technique C (if fixation was not possible). The overall survival rate during the 2-year follow-up was 88.2%; however, this decreased to 79% at 5 years. Only three patients had complications (two infections and one dislocation) requiring revision surgery. In the multivariable analysis, the tuberosity fixation technique (P = 0.012) and tuberosity anatomical consolidation (P < 0.001) were associated with improved Constant scores (median Constant Score 62.67 (technique A), 55.32 (technique B), 49.70 (technique C). Fracture-specific humeral implants (P = 0.051), the tuberosity fixation technique (P = 0.041), tuberosity anatomical consolidation (P < 0.001), and dementia influenced the achievement of functional mobility (P = 0.014). Tuberosity anatomic consolidation was positively associated with bone ingrowth fracture-specific humeral implants (P < 0.01) and a strong tuberosity fixation technique (P < 0.01). Conclusion RSA is used for complex and displaced fractures of the proximal humerus in older patients. Dementia was negatively correlated with functional outcomes. A window bone ingrowth fracture-specific stem combined with strong tuberosity fixation can yield better clinical and radiological results. Level of evidence Level II; prospective comparative study; treatment study
Biomaterials for Tendon Regeneration
Tendon is a highly complex tissue that exhibits high mechanical strength, flexibility, and extensibility to perform movement and physical exercise. However, it is exposed at a high-risk of injury, namely, at the tendon–bone interface (TBi).
The tendon natural healing process occurs by reactive scar formation, giving origin to a tissue that does not have the same characteristics of native tendon. As a consequence the healing response is suboptimal causing scar tissue formation, which implies inferior mechanical properties.
Tissue engineering using biomaterials trying to regenerate tendon tissue and improve clinical outcomes when treating tendon pathology is the focus of intense investigation worldwide. The authors review tendon structure and healing process and summarize the current knowledge about biomaterials for tendon regeneration.(undefined)info:eu-repo/semantics/publishedVersio
Reverse shoulder arthroplasty for irreparable massive rotator cuff tears: a systematic review with meta-analysis and meta-regression
Background: Massive rotator cuff tears (MRCTs) are very large tears that are often associated with an uncertain prognosis. Indeed, some MRCTs even without osteoarthritis are considered irreparable, and nonanatomic solutions are needed to improve the patient's symptoms. Reverse shoulder arthroplasty (RSA) is an option that can provide a more predictable pain relief and recovery of function. Nonetheless, outcomes after RSA for irreparable MRCTs have not been well defined. The aim of this study was to quantitatively aggregate the findings associated with the use of RSA in this subset of patients and analyze the effect on patient functional status and pain.
Methods: A comprehensive search was performed until October 2015 using MEDLINE, Scopus, Cochrane Database of Systematic Reviews, and Central Register of Controlled Trials databases. Studies that assessed the outcomes of RSA in patients with irreparable MRCT without osteoarthritis (with at least 2 years of follow-up) were included. If the results of MRCT without osteoarthritis were not possible to subgroup, the study was excluded. Methodologic quality was assessed using the Coleman Methodology Score.
Results: Included were 6 studies (266 shoulders) with a follow-up ranging from 24 to 61.4 months. The mean Coleman Methodology Score was 58.2 +/- 11.8 points. There was an overall improvement from preoperative to postoperative assessments of the clinical score (Cohen d = 1.35, P < .001), forward flexion (d = 0.50, P = .009), external rotation (d = 0.40, P < .001), function (d = 1.04, P < .001), and pain (d = -0.89, P < .001).
Conclusion: Patients with irreparable MRCT without presence of osteoarthritis have a high likelihood of achieving a painless shoulder and functional improvements after RSA.
Level of evidence: Level IV; Meta-AnalysisThis study received support from the Portuguese Foundation for Science and Technology: IF Development Grant to Antonio J. Salgado (IF/00111/2013) and a predoctoral scholarship to Pedro Moreira (PDE/BDE/113601/2015) from the PhD-iHES program. This work has been funded by Fonds Europeen de Developpement Economique et Regional (FEDER) funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038.Portuguese Foundation for Science and Technology: IF Development Grant to António J. Salgado (IF/00111/2013) and a predoctoral scholarship to Pedro Moreira (PDE/BDE/113601/2015) from the PhD-iHES program. This work has been funded by Fonds Européen de Développement Économique et Régional (FEDER) funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio
New tools for diagnosis, assessment of surgical outcome and follow-up
Objective evaluation of antero-posterior and rotatory laxity of the knee is a
critical issue in anterior cruciate ligament (ACL) research. Th is is essential to
allow surgeons to rigorously evaluate the outcome of the diff erent available
techniques. Furthermore it will make it possible to carry out advance predictions of which patients can benefi t from a particular approach, i.e. partial reconstructions,
single- or double-bundle techniques. Th e ideal method should be
able to assess anatomic and functional features of the ACL-defi cient knee, besides
being accurate, reproducible and cost-eff ective. Th is is an overview of the most recent
achievements and the scientifi c-technical considerations in this particular
area of research. Th is chapter presents the advantages and limitations of robotic
systems and manual instrumented devices compared to manual tests that are
commonly used in the clinical setting. It also highlights the Porto-knee testing
device as a new tool to assess laxity in ACL-defi cient knee during magnetic
resonance imaging. Insights of intraoperative navigation-assisted tools are also
considered