ABSTRACT

Introduction: Knee joint injection is a daily procedure in orthopedic outpatient visit. In order to obtain the maximum therapeutic benefit, it is necessary to perform the injection directly into the articular space and not into the adjacent structures. Objective: To establish the accuracy of the injection site into the knee joint in patients with grade II-III gonarthrosis. The portal approaches taken into consideration in this study were: Anterolateral (AL), Anteromedial (AM), Lateral Suprapatellar (LSP), Lateral mid-patellar (LMP), Medial mid-patellar (MMP) and Transtendinous (TT). Material and methods: A cross-sectional and descriptive study was conducted. A total of 123 knee joints were injected under fluoroscopy through the different approach portals. Variables: gender, positive arthrography at the first attempt, level of pain in patients during the procedure, as well as complications and side effects. Results: Lateral mid-patellar (LMP) approach was used on 20 knee joints with a 40% positive arthrography, 17 through LSP with 70.5%, 20 MMP with 90%, 21 AL with 61.3%, 26 M with 69.9%, 19 TT with 78.9%. Conclusion: The medial mid-patellar approach portal provides the greatest effectiveness in comparison to the other portals used on this study. Additionally, a greater percentage of positive arthrography was achieved at the first attempt.

Keywords: articular injection, gonarthrosis, knee joint.

RESUMEN

Introducción: La infiltración de la rodilla es una labor cotidiana en la consulta ortopédica. Para alcanzar el mayor potencial terapéutico en la infiltración articular, es necesario inyectar directamente en el espacio articular y no en estructuras adyacentes. Objetivo: Determinar la exactitud y eficacia de los diferentes puntos de infiltración de la rodilla en pacientes con gonartrosis grado II – III, considerando los portales de abordaje anterolateral (AL), anteromedial (AM), suprapatelar lateral (SPL), medio patelar lateral (MPL), medio patelar medial (MPM) y trans tendón (TT). Métodos: Estudio descriptivo y transversal. Se infiltraron 123 rodillas bajo control fluroscópico en las diferentes vías de acceso, teniendo como variables el sexo, artrografía positiva al primer intento, grado de dolor que presentan los pacientes durante la prueba así como complicaciones y efectos secundarios. Resultados: Se usó MPL en 20 rodillas teniendo una artrografía positiva en el 40%, 17 SPL con 70,5%, 20 MPM con 90%, 21 AL rodillas con 61,3%, 26 AM con 69,9%, 19 TT con 78,9%. Conclusión: El portal de abordaje MPM proporciona una mayor eficacia en comparación de los otros portales utilizados en este estudio. Siendo mayor el porcentaje de artrografías positivas en el primer intento de punción.

Palabras Clave: Infiltración articular, gonartrosis, punción articular, rodilla.

INTRODUCTION

Osteoarthrosis is a degenerative disease that affects diarthrotic joints. Radiographic changes are described by Kellgren and Lawrence in 1957: osteophyte formation on tibial tuberosity, non-uniform joint space narrowing, subchondral sclerosis and subchondral cyst formation with sclerotic borders. ^(1,2,3)

Gonarthrosis is a disease of polymorphic nature, usually in later stages of life. Therefore, complicating the distintion between an affected and healthy individual. This entails that more than one gen is cumulatively and quantitively implicated.

The knee joint is a common place for interventions of different procedures, which can be guided through imaging methods. ^(1,2)

Soft tissues surrounding the knee joint are commonly affected by sport activities and frequently require interventions guided by imaging methods. ⁽²⁾

Age is the most important risk factor, the relation between age and osteoarthrosis casts questions whether these changes are pathological or physiological related with aging. Osteoarthrosis affects more than 10% of population over 60 years old and is associated frequently with physical and psychological disorders. This warrants a high cost and the incidence increases as life expectancy increases. ^(2,4)

Worldwide it is recognized as a frequent cause of impaired life quality and disability after the fifth decade of life. The incidence of osteoarthrosis is directly related to age and in developed countries, there is one person in their productive years out of ten that is affected by this condition. ^(2,5,6)

Articular and soft tissues injection is a relatively simple procedure and generally, it achieves symptomatic relief with few side effects. Furthermore, it is the treatment of choice when soft tissues are involved in inflammatory processes. ^(1,3,7)

In order to achieve the greatest therapeutic benefit, injections are required to be directly guided into the intraarticular space and not into the adjacent adipose pouches or synovial tissues. The injection is particularly challenging in the absence of joint effusion. ^(2,3)

MATERIAL AND METHODS

A descriptive and cross-sectional study was conducted in a Third Level Attention Hospital of Instituto Mexicano del Seguro Social in Puebla, México. Different approach portals to the knee joint were assessed in patients with grade II-III gonarthrosis. Fluoroscopy was used to guide the procedure.

The population inclusion criteria were: 18 to 45 years old, both genders, grade II-III gonarthrosis and outpatients attended in the High Specialty Medical Unit, Traumatology and Orthopedics Hospital of Puebla. Exclusion criteria were important knee deformity, avian proteins hypersensitivity, intraarticular infection or in areas close to the injection site. Patients with adverse effects to the medication or willing to withdraw from the study were eliminated. The technique and research protocol were explained to each patient. Every patient signed an informed consent.

Data was organized on an Excel spreadsheet and subsequently on the SPSS V.25 IBM program for MAC. Descriptive statistics was used and Fisher´s exact test for the association between variables. It was considered as statistically important the value of p<0.05.

This study did not require external funding and material resources were provided by the researchers and the Mexican Institute of Social Security. Authorization was given by the Local Research Committee of the Mexican Institute of Social Security.

RESULTS

A total of 123 knee joints with grade II-III gonarthrosis were assessed. 87 (70.7%) were female and 36 (29.3%) male. Mean age was 55.72 (22 minimum - 92 maximum age). Lateral mid-patellar (LMP) approach portal was employed on 20 knee joints (16.3%), Lateral suprapatellar (LSP) on 17 (13.8%), Medial mid-patellar (MMP) on 20 (16.3%), Anterolateral (AL) on 21(17.1%), Anteromedial (AM) on 26 (21.1%), Transtendinous (TT) on 19 (15.4%). The injection through the different portals was achieved on the first attempt on 8 knees through LMP, 12 LSP, 18 MMP, 13 AL, 18 AM, 15 TT. The Medial Mid-patellar injection was the approach portal with most frequent positive arthrographies at the first attempt. According to statics with a level of significance of p=0.022. The frequency of positive arthrographies at first attempt of the other 5 approach portals are shown in Table 1.

The Numeric Rating Scale (NRS) was used to assess pain in patients during the procedure. Findings were that 43.9% of patients had mild pain (NRS= 0-3), 38.2% moderate pain (NRS= 4-7) and 17.9% severe pain (NRS=8-10). This data is shown on Table 2.

There was no correlation between gender and number of attempts of the injection, a shown in Table 3.

Both genders more frequently had mild pain. In addition, there was no correlation between gender and pain during the procedure (Table 4).

The different approach portals were taken into account to determine the one with the greatest number of injections at the first attempt. The MMP achieved a greater number of injections with 18 at the first attempt and 2 injections with needle reposition to achieve a positive arthrography. According to statics with a level of significance of p=0.022. Results of the other portals are shown in table 1.
Pain perceived in the different approach portals was assessed, MMP proved to be the portal with no patients in severe pain and 14 (70%) patients in mild pain. Results are shown in table 5.

DISCUSSION

Injection into the knee joint is used by orthopedists and performed in the doctor´s office with no direct vision. This can lead to medical errors in the procedure when experience and knowledge are lacking. ^(1,4,8)

Despite being a relatively simple procedure, the different approach portals deliver different results in terms of pain and positive arthrography achieved at the first attempt. Orthopedist use the approach portal which are most comfortable, regardless this not being the best option. Hence, the importance of determining the effectiveness with objective measurements of each approach portal and establish a portal of choice, avoiding treatment failures and complications due to needle malposition. ^(2,9,10,11)

According to our results, the portal most effective for the injection is the Medial Mid-patellar, with 18 patients with positive arthrography at the first attempt, 24 of them had mild pain (NRS 1-3) and 0 had severe pain (NRS 8-10), which does not concord with other authors (6,12,13,14,15)

Findings in Jackson DW and cols´ trial were different and among the approach portals using fluoroscopy and a contrast agent, the Lateral Mid-patellar had better results, with 93% of injection at the first attempt. ⁽³⁾

Wind WM and cols published a trail with 131 knee joints. It was concluded that the lateral knee border as injection site was not reliable since a positive injection was achieved in less than half of cases. ⁽⁶⁾

Hermans J and cols in their 2011 systematic review included 9 studies in which different approach portals were compared in European population. It was concluded that the injection of choice was the superolateral with 90% of effectiveness in the 9 studies. ⁽⁷⁾

Comparing the previous mentioned review with our study, findings in this were SPL had 70.5% of effectiveness and MMP 90%. The sample was of 17 and 20 patients respectively.

In a 2014 systematic review, Douglas R considered 11 case series that punctured knee joint for injection and evacuation. In this review, the Waddel approach portal (modified AM) is encouraged to use. However, the heterogenous nature of this study in terms of knee pathology deprives it of a solid evidence for the use of this portal in gonarthrosis. ⁽⁸⁾

In this study, a total of 123 knee joints with grade II-III gonarthrosis were injected through different portals. Results regarding positive arthrography at first attempt were 8 knees through LMP (40%), 12 LSP (70.5%), 18 MMP (90%), 13 AL (61.9%), 18 AM (69.9%) and 15 TT (78.9%).

With the precedence of this study, it will be feasible to lead a similar study with a greater sample and resources and subsequently conduct it in similar patients.

The intraarticular injection into the knee joint must be handled as an efficient technique, reliable and with the minimal pain. Multiple studies have compared the accuracy of the different portals, having inconsistent results between them. The result with greatest prevalence of better results was lateral suprapatellar portal. ^(10,11)

Additionally, in this study a correlation, not completely measurable, was found between the level of pain and overweight. Results established that overweight patients had greater pain during the procedure. Despite not being a measurable variable, it is encouraged to lead studies in order to establish a relation between pain in orthopedic procedures and overweight.

The importance of this study resides on the frequency in which the injection is performed with no objective approach to verify the actual intraarticular injection. Consequently, it is urged to implement similar studies to this in order to standardize the injection method criteria. An adequate knee joint injection entails a responsibility from the physician to the patient in terms of health and economy since this is decisive step that defines whether the treatment has a favorable course or not.

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