Stiffness Before and After Total Knee Arthroplasty

Exposing the Stiff Knee

Exposure of the ankylosed knee can be difficult. Extreme care must be taken to avoid excessive stress on the patellar tendon insertion that might lead to patellar tendon avulsion. The two most common methods to facilitate exposure are a proximal release or a tibial tubercle osteotomy. I prefer the proximal release to avoid the potential morbidity of tubercle osteotomy, which includes wound-healing difficulties, problems with union of the osteotomy, and the potential for stress fracture at the osteotomy site. The classic proximal release is the so-called quadriceps snip initially described by Garvin and associates. I perform a modification of the snip in which the medial arthrotomy is taken to the top of the quadriceps tendon on the medial side and then brought distally along the lateral side of the tendon in an inverted V configuration ( Fig. 6.1 ). I prefer this release because it is easy to close and seal the joint to prevent leakage of the hematoma.

This procedure can also be extended to a formal V-Y quadricepsplasty to lengthen the quadriceps mechanism when appropriate. The proximal quadriceps release effectively takes tension off the patellar tendon and allows the patella to be turned like the page of a book. The surgeon then has access to lateral parapatellar scar tissue and the lateral retinaculum to perform a preliminary lateral release to further facilitate eversion and exposure. Despite these measures, I think it is advisable to place a smooth ⅛-inch pin into the tibial tubercle to further prevent the patellar tendon from avulsing or peeling off its insertion ( Fig. 6.2 ).

Exposing the Knee Ankylosed in Extension

When the knee is ankylosed in extension (the knee has limited potential to flex), I recommend the following sequence of maneuvers. An inverted V or quadriceps snip is performed on initial exposure. Flexion of the knee is achieved by gentle manipulation. If the anterior cruciate ligament (ACL) is present, it is surgically released. In certain knees (in postseptic or juvenile rheumatoid arthritis), a joint line osteotomy using a saw or osteotomes may be required. A prophylactic tubercle pin is placed. During preparation of the femur, maximal trochlear resection is performed short of notching the anterior cortex. During preparation of the patella, maximal patellar resection is performed, leaving a remnant, however, of at least 10 mm in thickness. These two measures enhance flexion by increasing the quadriceps excursion. At the same time, the surgeon should avoid overstuffing the joint with an oversized femoral component.

At the time of closure, flexion against gravity is measured with the capsule closed anatomically. If this range is deemed inadequate for the specific patient, then consideration can be given to extending the inverted V quadriceps incision to a formal V-Y quadriceps lengthening ( Fig. 6.3 ). The disadvantage of V-Y quadriceps lengthening is the resultant extensor lag, which will depend on the amount of lengthening. The quadriceps usually will recover to an acceptable amount, but the patient may have to be braced during ambulation until active extension is −15 degrees or better.

Exposing the Knee Ankylosed in Flexion

I recommend the following measures in exposing the knee that will not straighten because of a severe flexion contracture. Again, a quadriceps snip or inverted V proximal quadriceps release is indicated. For most primary knees, I start with femoral resection. For the knee with a severe flexion contracture, a conservative tibia-first resection is a reasonable way to help mobilize the knee. When the tibial resection is performed, it is advisable to apply no posterior slope to the cut. This is because every degree of posterior slope is a degree of flexion imparted to the prosthetic components.

In most primary knees, I preserve the posterior cruciate ligament (PCL) (see Chapter 1 ). One of my indications for PCL resection and substitution is the knee with a severe flexion contracture. PCL resection facilitates release of the posterior capsule, and substitution helps correct knees with posterior subluxation of the tibia in association with a contracture ( Fig. 6.4 ).

Whether the PCL is preserved or substituted, it is important to remove all posterior femoral and tibial osteophytes, which tent up the posterior capsule. Further posterior capsule release can be achieved by using a periosteal elevator or osteotome to strip the capsule from the femur and tibia. Distal femoral resection is increased by 2 mm for every 10 to 15 degrees of contracture up to a limit of 12 to 14 mm. Resection greater than this amount can compromise the integrity of the collateral ligaments. Stabilization with a Total Condylar III (DePuy, Inc., Warsaw, Indiana) type of prosthesis sometimes must be considered for persistent flexion gap laxity.

At the time of capsular closure, the medial capsule is advanced distally on the lateral capsule to minimize the extensor lag that would be created by use of an anatomic capsular closure ( Fig. 6.5 ) (see Chapter 7 ).