Ali Oliashirazi
DEFINITION
Gaining exposure during revision total knee arthroplasty (TKA) and primary TKA for the ankylosed knee can be challenging.
Although over 90% of revision TKA procedures can be performed through a standard surgical approach, the surgeon should be familiar with more extensile techniques in case one of those must be used to avoid extensor mechanism disruption.4
If adequate exposure is not obtained, a graduated approach is necessary.
Quadriceps snip is used most commonly, followed by tibial tubercle osteotomy or V-Y quadriceps turndown.
Although it may be possible to perform a prosthetic implantation without using an extensile exposure in the ankylosed knee, quadriceps contracture can limit extensor mechanism excursion, leading to poor postoperative flexion.
V-Y quadricepsplasty may be performed after prosthetic insertion to improve flexion.6
TECHNIQUES
STANDARD APPROACH
Any skin incisions from previous procedures are clearly marked before skin preparation begins.
Although a straight, midline anterior incision is preferred, because the vascular supply to this skin is primarily from the medial side, the most lateral useable incision is chosen. Previous skin incisions are intersected at an angle of no less than 60 degrees.
Thick flaps are developed that include the superficial fascia.
A medial parapatellar arthrotomy is then made at the junction of the medial and central thirds of the quadriceps tendon.
Subperiosteal dissection of the tibia is then extended from the tibial tubercle to the posteromedial corner, including release to the semimembranous insertion.
A suprapatellar pouch, as well as the medial and lateral gutters, is then reestablished, all adhesions are released, and a thorough synovectomy is performed.
All peripatellar scar tissue is removed.
The knee is then gently flexed. The tibia is externally rotated and subluxed anteriorly, thereby reducing tension on the extensor mechanism.
If the extensor mechanism is still under too much tension, dissection is carried distally and the superficial medial collateral ligament is released, followed by lateral retinacular release, making sure to preserve the lateral superior geniculate.
If adequate exposure still is not possible, a quadriceps snip is performed, as described in Chapter AR-27.
In most revision TKAs, adequate exposure can be obtained with these maneuvers.4
TIBIAL TUBERCLE OSTEOTOMY
Tibial tubercle osteotomy (see Chap. AR-26) is chosen in cases with difficult stem or cement extraction or patients with patella baja.3
QUADRICEPS TURNDOWN
The quadriceps tendon is exposed proximally to the insertion of the vastus lateralis and medialis muscles.
The medial parapatellar arthrotomy is extended proximally to the insertion of the vasti.
The quadriceps is then incised distally and laterally at an angle of about 45 degrees along the insertion of the vastus lateralis (TECH FIG 1).
This inverted V creates a distally based flap that includes the patella. Essentially, the medial incision is connected to the lateral release.
Care should be taken to preserve the lateral superior geniculate artery.
The patella is now “turned down” anterolaterally, providing excellent exposure to the joint.
TECH FIG 1 • Line of incision. (Based on drawing by Dr. Greg Hendricks, Assistant Professor, Department of Orthopaedics, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV.)
V-Y QUADROPLASTY
The quadriceps is repaired in situ with multiple interrupted no. 2 nonabsorbable sutures, and ROM is assessed.
If ROM is acceptable, closure is completed, leaving the lateral retinacular release open.
If increased passive ROM is desired, the V is converted to an inverted Y.
From 1% to 2% of advancement can be performed.
The knee is flexed, and sutures or clamps are placed along the apex of the Y.
Once appropriate lengthening is established, no. 2 nonabsorbable sutures are used to close the medial side of the quadriceps mechanism.
The lateral retinacular release is left open.
The lateral limb of the quadricepsplasty is covered by closing the quadriceps mechanism to the superficial fascia of the vastus lateralis (TECH FIG 2).
The maximum flexion of the knee that will not put undue tension on the repair is recorded prior to routine skin closure.
TECH FIG 2 • Closure. (Based on drawing by Dr. Greg Hendricks, Assistant Professor, Department of Orthopaedics, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV.)
POSTOPERATIVE CARE
One disadvantage of V-Y quadricepsplasty is that it is necessary to modify postoperative rehabilitation.
Maximum passive flexion to avoid tension on the repair is determined intraoperatively, after capsular closure. This is not exceeded in the first 2 weeks.
The patient is placed in an immobilizer immediately postoperatively.
A hinged brace is fitted after the first dressing change. A flexion stop is used for the first 2 weeks.
Passive knee extension and active knee flexion are done for 6 weeks.
Partial weight bearing is required for 6 weeks.
The brace is locked in extension at night and with ambulation until the extensor lag is less than 15 degrees.
OUTCOMES
Knee scores are similar to those of patients who have had revision TKA and reflect the difficulty of knees that need this procedure.
In one study2 that compared patients who had had quadriceps turndown and tibial tubercle osteotomy to patients whose revision TKAs were performed with routine exposure, patients in the quadriceps turndown and tibial tubercle osteotomy groups had equivalent postoperative scores, which were significantly lower than those of patients in the routine exposure revision group. The turndown group had a higher increase in arc of motion than the osteotomy group, but they also had a higher degree of extension lag. The turndown group also had a lower percentage of patients who considered their surgery unsuccessful in relieving pain and return of function, and a lower percentage of patients who had difficulty with kneeling and stooping.2
In a mixed population of primary and revision TKA, Cybex testing revealed that the quadriceps was weaker on the VY quadricepsplasty side, but this did not reach statistical significance. Only 5 of 14 patients had extensor lag greater than 5 degrees, with active extension lag averaging 4 degrees (range 0 to 20 degrees).7
COMPLICATIONS
Patellar osteonecrosis was observed in 8 of 29 patients with quadriceps turndown in one study.5 It is critical to preserve the superior lateral geniculate artery.
One case of minor wound dehiscence also was reported in a hemophiliac patient during manipulation under anesthesia after TKA using VY quadricepsplasty.
REFERENCES
1. Aglietti P, Windsor RE, Buzzi R, et al. Arthoplasty for the stiff or ankylosed knee. J Arthroplasty 1989;4:1–5.
2. Barrack RL, Smith P, Munn B, et al. Comparison of surgical approaches in total knee arthroplasty. Clin Orthop Relat Res 1998;356:16–21.
3. Clarke HD, Scuderi GR. Revision total knee arthroplasty: planning, management, controversies, and surgical approaches. Instr Course Lect 2001;50:359.
4. Della Valle CJ, Berger RA, Rosenberg AG. Surgical exposures in revision total knee arthroplasty. Clin Orthop Relat Res 2006;446: 59–68.
5. Parker DA, Dunbar MJ, Rorabeck CH. Extensor mechanism failure associated with total knee arthroplasty: prevention and management. J Am Acad Orthop Surg 2003;11:238–247.
6. Scott RD, Siliski JM. The use of a modified V-Y quadricepsplasty during total knee replacement to gain exposure and improve flexion in the ankylosed knee. Orthopedics 1985;8:45.
7. Trousdale RT, Hanssen AD, Rand JA. V-Y quadricepsplasty in total knee arthroplasty. Clin Orthop Relat Res 1993;286:48–55.