**6. Surgical technique**

The type of anesthesia should emphasize the muscle relaxation and minimize blood loss. Usually, the epidural anesthesia associated with peripheral nerve block as adductor canal provide decrease of narcotic usage and postoperative pain. The tranexamic acid (20–60 mg/kg) can be administrated intravenous during the anesthetic induction in attempt to reduce the blood loss. The use of tourniquet is

*Primary Total Arthroplasty in Stiff Knees DOI: http://dx.doi.org/10.5772/intechopen.106225*

**Figure 2.** *Radiography in lateral view with 30° of flexion.*

questionable and can be avoidable in STK patients [16, 17]. The use of sterile drape is recommended, and the leg should be free to move during the TKA. The range of motion (ROM) and ligamentous stability should be addressed prior the incision and documented.

A straight midline incision should be used, if there is not prior surgical scar. If an anterior longitudinal knee scar is found, the skin incision starts more proximally. Usually, the skin is adherent to the subcutaneous tissue and careful dissection may be required to mobilize the skin. This step assists the deep subfascial dissection and facilitates the dermis and epidermis closure. A medial parapatellar arthrotomy is performed with capsule opening and releases the adhesions in the suprapatellar pouch and plane between anterior distal femur underneath the quadriceps tendon. After this step, cleaning the medial and lateral gutters may be required to gain adequate exposure. All the fibrotic tissues should be removed. The patellar tendon is identified and protected during the TKA, and the space posterior to the tendon freed by sharp dissection with the scalpel or eletrocautery.

The next step is the patellar eversion. The difficulty to dislocate the patella laterally, in SKN, remains a problem. The lateral retinacular release can be performed, if the knee remains stiff with flexion less than 40° and the lateral patellofemoral ligament is cut to assist the patellar eversion. An extensive transquadricipital approach, the rectus snip, can be performed to improve and provide good exposure with low risk related to the extensor mechanism damage. The rectus tendon is transected in an oblique fashion, around 45°, in a superior and lateral direction [18]. Orienting the rectus snip distally allows for conversion to a V-Y quadricepsplasty that the surgeon incises the rectus tendon and vastus lateralis, but not the lateral retinaculum [19, 20]. This approach preserves the superior lateral geniculate artery, which provides the major blood supply to the patella, when a medial arthrotomy has been performed. However, this technique is not recommended in the presence of subluxated or dislocated patella laterally. In this scenario, an extensive lateral retinacular release can be performed and the patella is everted and knee is flexed gently. It is recommended to be cautious during this maneuver to avoid patellar tendon avulsion from the tibia tubercle, bone avulsion, and medial collateral ligament (MCL) tear in the progression for the knee flexion [21]. The placement of a metallic pin through the tibial tubercle can decrease the stress over the patellar tendon and hinder the avulsion. The combination of a quadriceps snip and lateral release provides an adequate exposure for most SKNs. The rectus tendon and vastus lateralis muscle are repaired, but the lateral retinacular incision is left open. This approach has the advantage of not requiring modification of postoperative rehabilitation [22].

In the varus deformity, the subperiosteal medial release is then continued, with a sharp scalpel, an electrocautery or an osteotome, as the knee is further flexed and the tibia externally rotated. Dissection should begin in extension on the bone surfaces in attempt to mobilize the soft tissues. Then, skeletonization of the tibia and femur has been performed to allow knee flexion for adequate exposure. For severe varus SKNs, a medial transepicondylar femoral osteotomy may be required. In the valgus deformity with SKNs, a decision must be made to choose an anterior longitudinal traditional incision or lateral approach described by Keblish [23].

The tibial tubercle osteotomy (TTO) can be performed to extend the incision distally for the most difficult SKNs. The osteotomy should encompass at least 8 centimeters (cm) distal to the top of the tibial tubercle. The bone cut is made with an oscillating saw from medial to lateral, and then the lateral cortex is transected with an osteotome. Muscle attachments to the lateral tibial crest with a periosteal soft tissues hinge are left preserved. Two or three wires are passed to encompass the tubercle during closure [24]. Furthermore, two or three screws can be used to stabilize the TTO, in patients with good bone quality. In osteoporotic bone, TTO is not recommended. Before wound closure, the knee was taken through a passive ROM to assure osteotomy fixation and patellofemoral tracking. Postoperatively, the patients wore a protective knee immobilizer while up and walking for the first 6 weeks.

For the ligament balancing, sequential soft tissue release can be performed to correct the angular deformity; if posterior cruciate ligament (PCL) appears to be functional and balanced, cruciate retaining (CR) prosthesis can be used, but this is an uncommon scenario. For a rigid or severe flexion, contracture may be necessary to cut more distal femur (2 mm) to achieve a straight knee in extension. It is not a feasible solution to cut more distal femur than 2 mm due to the high risk to raise the joint line. Then, the tibial and femoral bone cuts are recommended to place the laminar spreaders in extension and flexion in 90°. A curved osteotome is used to remove the posterior osteophytes and release the posterior capsule (**Figure 3**). This maneuver is essential to open the flexion gap [25](**Figures 4** and **5**).

*Primary Total Arthroplasty in Stiff Knees DOI: http://dx.doi.org/10.5772/intechopen.106225*

**Figure 3.** *Removal of posterior osteophytes in the femoral condyles.*

**Figure 4.** *Narrow flexion gap prior the posterior release.*

Moreover, more constrained implants as posterior stabilized (PS) models with an elevated polyethylene post are considered as the implant of choice due to the PCL contracture in SKNs. If during insertion of trial components, the knee is unstable in both coronal and sagittal plane, and a more constrained modular component with augments and stems or hinged prosthesis can be chosen. It is recommended to place the femoral component more posterior to decrease the flexion gap, mainly in PS implants. The level of constriction will depend the extent of the ligamentous releases and the amount of bone loss encountered during the TKA. A tumor prosthesis or custom

**Figure 5.** *Opening of the flexion gap with laminar spreaders.*

implants may be needed in extremely SKNs, especially in extension. The prosthesis chosen should have options available for femoral and tibial implants in attempt to re-establish the anatomic joint line with available metallic augments (**Figures 6** and **7**). Care should be taken to avoid overstuff in the patellofemoral articulation that can lead to a flexion contracture and anterior knee pain.

In ankylosed and after knee arthrodesis, the patellar and proximal tibial cut can be performed in the beginning to obtain more space and promote a better exposure during the TKA. A posterior capsule release with the electrocautery and the laminar spreaders positioned in extension can help after the bone cuts to achieve zero degrees. For a more severe contracture above 30°, the quadricepsplasty may be needed in attempt to elongate the extensor mechanism and to re-establish the joint line. In patients with MCL insufficiency and bone loss in the metaphysis, a hinge TKA can be considered.

The closure of the quadriceps tendon should be performed between 30° and 60° of knee flexion, depending on the preoperative gravity of the SKN. The type of quadriceps release or TTO performed should be taken into account to consider the angulation of knee flexion during the closure. The intraoperative ROM after this surgical step should be documented with a photograph to demonstrate for the patient and the physiotherapist [26].
