*2.1.2 Intraoperative period*

At the time of surgery, technical errors during the bone cut, soft tissue procedure, and implantation, which relate to an imbalance in flexion and extension gaps, are the most frequent causes of postoperative stiffness. All of these conditions may result in limitation of motion both flexion and extension after TKA (**Table 1**) [4, 9].

*Complications after Total Knee Arthroplasty: Stiffness, Periprosthetic Joint Infection… DOI: http://dx.doi.org/10.5772/intechopen.105745*


#### **Table 1.**

*The intraoperative conditions which result in stiff TKA.*

#### *2.1.3 Postoperative period*

There are several factors causing stiffness following TKA in this period, including inadequate rehabilitation and poor patient motivation, deep infection, arthrofibrosis, complex regional pain syndrome (CRPS), associated stiffness or pain derived from the adjacent joints or spine that alters knee motion, and heterotropic ossification (HO) [14]. Adequate postoperative pain management is essential in improving functional recovery and achieving rehabilitation protocol, especially knee motion enhancement [15]. Deep infection or PJI is one of the conditions leading to difficulty in ROM with chronic dull pain. It should be considered, especially in patients who developed stiffness after achieving adequate ROM [4, 14]. The details of this condition are described later in this chapter.

Arthrofibrosis after TKA is the most common cause of stiffness with an incidence ranging from 1.2 to 17 percent [9]. The etiology is multifactorial and the exact pathophysiology is unclear. Patients with poor preoperative ROM, higher complexity surgery, and a history of previous knee surgery increase the risk of excessive fibrous tissue formation after TKA. The theory of developing arthrofibrosis is disruption of cytokines and growth factors signaling cell growth, differentiation, and death, resulting in uncontrolled proliferation of fibroconnective tissue [16]. The histology is characterized by metaplasia of calcified tissue, myofibroblasts, and excessive fibrosis, with the increasing number of macrophages and lymphocytes in the periarticular tissue [17, 18]. The clinical manifestation is broad spectrum, from a localized lesion to a generalized involvement of the entire joint, and results in the formation of extensive extra-articular fibrous tissue.

Recently, there is no gold standard for diagnosis of arthrofibrosis, and also no effective method to prevent the idiopathic arthrofibrosis after TKA, apart from patient education and early mobilization [4].

#### **2.2 Treatment**

Initial evaluation of stiff TKA to assess the causes is necessary before management. A correct diagnosis leads to correct treatment. The evaluation should review back to the preoperative status of the patient, especially the risk factors mentioned above. The radiological examination should perform in case of suspicious mechanical problems from surgical errors of bone cut and implantation. Do not hesitate to work up for PJI if infection or wound-related complications that predispose the patient to infection are suspected [4, 9].

There are various treatment options for stiff TKA: manipulation under anesthesia (MUA), arthroscopic arthrolysis, open arthrolysis, and revision surgery [4].

#### *2.2.1 Manipulation under anesthesia (MUA)*

The purpose of MUA is to break immature adhesions within the knee in patients who disadvantage of self-training or regular rehabilitation programs and accelerate the initial rehabilitation process [19]. This procedure should be performed within 6–8 weeks after initial TKA before the development of mature adhesions which increases the likelihood of complications after MUA, especially periprosthetic fractures or rupture of the extensor mechanism [20]. Aggressive rehabilitation is necessary to prevent further and recurrent stiffness. A systematic review by Fitzsimmons et al. showed a mean gain in knee motion from 30 to 47 degrees after MUA [7].

#### *2.2.2 Arthroscopic arthrolysis*

Arthroscopic arthrolysis is a minimal invasive surgery that resects fibrosis directly in the suprapatellar pouch, medial and lateral gutters, and also in the intercondylar groove [4]. The indication of this operative procedure is painless, stiff TKA after non-progression of conservative treatment for 3 months. Disadvantage is inadequate arthrolysis because of poor access to the posterior structure and the area above the suprapatellar pouch [9]. A systematic review demonstrated improvement of overall ROM between 18.5 and 60 degrees, which also achieved 30.8–42 degrees even performing arthroscopic arthrolysis after 1 year of index TKA [7].

#### *2.2.3 Open arthrolysis*

Open lysis of adhesions is recommended in case of severe ROM limitation which impedes the use of arthroscope without component malposition and after the failure of conservative treatment. This operative procedure can provide a broad assessment of the knee joint and fibrosis resection should be performed meticulously. However, exposure to the joint may be difficult from adhesions and need further operative technique, for example, tibial tubercle osteotomy, quadriceps snip, or VY-plasty [4, 9]. A systematic review by Fitzsimmons et al. showed an average increasing of ROM between 19 and 31 degrees after open arthrolysis [7].

#### *2.2.4 Revision surgery*

This is the final treatment option reserved for stiffness from surgical errors that need to be corrected. Accurate analysis of the errors is required for planning the revision correctly to meet the patient's satisfaction [4].
