Revision Total Knee Arthroplasty Via Tibial Tubercle Osteotomy
Jeffrey A. Geller, MD
Nana Sarpong, MD, MBA
Dr. Geller or an immediate family member is a member of a speakers’ bureau or has made paid presentations on behalf of Smith & Nephew; serves as a paid consultant to or is an employee of Smith & Nephew; and has received research or institutional support from Orthopaedic Scientific Research Foundation, OrthoSensor, and Smith & Nephew. Neither Dr. Sarpong nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this chapter.
PATIENT SELECTION
Total knee arthroplasty (TKA) is a well-proven intervention that relieves pain and improves the quality of life in individuals with advanced degenerative joint disease of the knee. The number of TKA surgeries performed annually in the United States has increased steadily over the past 20 years and is anticipated to reach approximately 3.5 million by the year 2030. It also has been estimated that approximately 268,000 revision TKAs (rTKAs) will be performed per year by 2030.1 Some of these revisions will be performed because of a painful and stiff knee, necessitating increased knowledge of the different techniques used to gain safe, wide exposure for revision knee surgery.
Several techniques have been developed to improve exposure to the knee during a difficult revision. The quadriceps snip, whereby the surgeon improves the ability to evert the patella by making an oblique incision through the midaspect of the rectus femoris tendon, is the most common and direct means to gain access to the knee. Although the quadriceps snip should be the workhorse procedure, tibial tubercle osteotomy (TTO) is an important procedure for the knee arthroplasty surgeon to have in his or her armamentarium,2 especially when the quad snip is not sufficient. The TTO, as initially described by Whiteside, can be used to improve exposure for both rTKA and complex primary TKA.3 Before even entering the operating room, the surgeon should have a sense of whether the patient will require a more extensive surgical approach to avoid damage to a stiffened, fibrosed extensor mechanism. In most patients, a quadriceps snip procedure will provide sufficient exposure, but opting for the TTO early may be judicious, to avoid being forced to resort to a secondary TTO if the quadriceps snip fails to provide appropriate exposure.
Indications
The primary indication for TTO is a severe, rigid lack of range of motion (ROM). Strong consideration should be given to TTO when the ROM is less than 90° of flexion, especially when accompanied by a severe fibrous block in motion, as demonstrated by passive ROM testing under anesthesia. These patients often have a flexion contracture that further complicates the surgical exposure, which should be an early indication that a more extensile procedure is necessary to avoid extensor mechanism avulsion. Such scenarios are common in the setting of a prosthetic joint infection (PJI) when rTKA requires a two-stage procedure; where there may be further stiffness caused by heterotopic bone formation; when rTKA is performed to treat a stiff and painful primary TKA; or when the aseptically loosened TKA has been neglected for a long time, leading to progressive stiffness.
Contraindications
The main contraindication to TTO is extremely poor bone stock in the proximal tibia. This may be due to infection, extreme osteolysis, or a poor fibrous union from a prior TTO, although this is extremely rare. In general, this scenario can be overcome by extending the osteotomized segment farther distally into the diaphyseal portion of the tibia, where there is better bone stock that can be repaired at the conclusion of the procedure.
PREOPERATIVE IMAGING
The recommended preoperative images are the standard radiographs that are obtained in the routine workup of a patient, including AP weight-bearing, lateral, and sunrise views (Figure 1). More relevant is the physical examination of the patient, specifically the preoperative ROM assessment.
PROCEDURE
Room Setup/Patient Positioning
Patient positioning for rTKA via TTO is the standard supine positioning for TKA, although a padded bolster under the ipsilateral hip is essential to keep the lower extremity from excessive external rotation. Similarly, a padded hip positioner lateral to the tourniquet may also be helpful to avoid excessive rotation of the extremity.
 FIGURE 1 Weight-bearing AP (A), lateral (B), and sunrise (C) radiographs of the knee of a patient who underwent a total knee arthroplasty (TKA) 1 yr earlier. The TKA was revised for pain and stiffness. |
Special Instruments/Equipment/Implants
The tools needed to successfully perform a TTO are found in most operating rooms. It is necessary to have a full set of straight and curved osteotomes and a motorized microsagittal saw. Repair of the TTO has been described using either wires or screws. The instruments needed depend on the surgeon’s preferred method. When wires are used to repair the TTO, a standard 2.7-mm drill bit and 18-gauge stainless steel wire are necessary. A wire tightener is also helpful to facilitate the twisting and securing of the wires; several modifications of this device are available. If screws are preferred, 6.5-mm cannulated screws with a washer can be used.4 Our preference is to use wires because they have lower profile and are less likely to cause fracture through the osteotomized fragment than are screws.
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