Management of stiffness following total knee arthroplasty: A systematic review

Abstract

Aim

The aim of the study was to systematically evaluate the outcome of four main modalities of treatment for arthrofibrosis that develops subsequent to a total knee arthroplasty (TKA), namely manipulation under anesthesia (MUA), arthroscopic debridement, open surgical release and revision TKA.

Materials and methods

A computerised search was conducted for relevant studies published from 1975 onwards in all the major databases and various search engines. A total of twenty-five studies were selected, representing a total of 798 patients. Studies that passed the inclusion criteria were then subjected to quality assessment using the Newcastle-Ottawa Scale. On assessment, the 25 studies scored a total of 77 stars out of a possible 125. Two studies were prospective in design, while the remaining case series were retrospective in nature. The primary outcome measures assessed were increase in range of movement (ROM) and the Knee Society Score (KSS) at final follow-up.

Results

Our results showed that manipulation under anesthesia (MUA) had a mean increase in ROM of 38.4°, arthroscopic release had a mean increase of 36.2°, open surgical release had a mean increase of 43.4° and revision TKA had a mean increase of 24.7°. No significant differences were found in the KSS of the four treatment modalities.

Our analysis suggests that open surgical release would be the most beneficial option for patients who are fit to undergo secondary surgery if their lifestyle requires a higher ROM for activities of daily living. However, there were methodological limitations as majority of the papers were case series, which decreased the quality of the evidence available.

Introduction

Total knee arthroplasty (TKA) is considered to be the most effective and reliable treatment for patients with advanced osteoarthritis of the knee. The definition of stiffness varies widely throughout the available literature, resulting in different reported ranges of prevalence. However, two large series performed in recent times by Kim et al. [1] and Yercan et al. [2] report the prevalence to be 1.3% in 1000 knees and 5.3% in 1188 knees respectively. Post-operative stiffness, which is attributed to arthrofibrosis which occurs in the knee joint, can be extremely debilitating for the patient, often making activities of daily living such as climbing stairs or rising from a chair painful and difficult [3], [4].

The causes of arthrofibrosis after total knee arthroplasty surgery are multifactorial. Several risk factors for stiffness in the knee post-TKA have been identified. These risk factors can be divided into pre-operative, per-operative and post-operative. The most significant and well-recognised cause of a stiff TKA is decreased pre-operative range of movement [5]. A correlation also has been demonstrated between history of previous surgery and diabetes mellitus and stiffness post-TKA [6]. Per-operative risk factors leading to stiffness include incorrect flexion–extension gap, malpositioning of components, inadequate femoral or tibial resection, excessive joint line elevation, creation of an anterior tibial slope and incomplete resection of posterior osteophytes. Post-operative risk factors leading to decreased range of movement include poor patient motivation, lack of compliance with physiotherapy, deep infection, arthrofibrosis of the knee joint, patellar complications, complex regional pain syndrome and heterotopic ossification [7].

The definition of stiffness in the knee varies within the available literature, Christensen et al. [8] described it as an arc of motion less than 70° whereas Kim et al. [1] describe it as a flexion contracture of > 15° and/or < 75° of flexion. Another parameter that is used to measure stiffness in the knee is the Knee Society Scoring System, which provides a uniform method to quantify the amount of pain that the patient is experiencing in the knee. It encompasses various aspects of knee movement and function, such as pain, flexion contracture, extension lag, range of movement, alignment and stability [9].

The various treatment options available for arthrofibrosis of the knee are manipulation under anesthesia (MUA), arthroscopic arthrolysis, open arthrolysis and finally revision TKA. MUA is generally regarded as the first step in the treatment of a stiff TKA, especially in the first two months [2]. The technique of performing MUA is uniform, the patient is put under adequate anesthesia to the point of maximum relaxation and the ipsilateral hip is flexed to 90°. The knee is then flexed slowly and gently until the audible and palpable separation of adhesions no longer occurs [10]. Arthroscopic release is another treatment option for the stiff TKA, and is usually performed in moderately painful and stiff knees, preferably within 3 to 6 months after TKA. In arthroscopic debridement, the arthrofibrosis is relieved by resecting large fibrous bands of scar tissue under arthroscopic visualisation [6]. In certain cases, open surgical release is recommended to patients, especially in the case of severe stiffness (< 60°). Other cases of severe stiffness, especially those with malpositioned implants, require a revision TKA. Although studies have been performed in the past to examine the effect of these treatment modalities on the stiff knee post-TKA, there is paucity of evidence regarding the comparable effectiveness of these treatments.

The aim of this systematic review, therefore, was to pool the studies dealing with different treatment strategies available in order to summarise the outcome of these treatment modalities. In the literature reviewed, different treatments of post-TKA stiffness have been explored to compare the outcomes of improvement in range of movement and improvement in the Knee Society Score (KSS).