LIVRE JDG 2012

E. Gancel, R.A. Magnussen, F. Trouillet, S. Lustig, E. Servien, P. Neyret

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compartment and the lateral patellofemoral

joint. We interested only by the lateral

compartment. The patient who received a

medial UKA was also excluded. Another

patient received a lateral UKA after a medial

UKA on the same knee. In order to obtain the

most homogeneous group, this patient was

brought of the study. Eleven patients (six right

knees and five left knees) form the study group.

The average age at the time of the UKA was

66.7 years (range: 49 to 79 years). The mean

patient weight was 62.7 kg (range: 49 to 80).

The mean body mass index was 23.9 kg/m

(range 19.1 to 29.3 kg/m

Surgical Indications

Candidates for UKA demonstrated isolated

lateral compartment narrowing with complete

or near complete joint space loss. Patients with

a coronal plane deformity greater 14 degrees of

knee valgus were excluded along with patients

inwhoma stress radiograph did not demonstrate

reductibility of any coronal plane deformity.

The integrity of the anterior cruciate and medial

collateral ligaments were verified clinically

and radiographically. Finally, patients were

required to have at least 90 degrees of flexion

and an extension deficit of less than 10 degrees.

Weight alone was not considered an absolute

contraindication.

Partial lateral patellar facetectomy performed

concurrently in patient with:

objective

evidence of lateral patellofemoral degenerative

disease with complete joint space loss,

localized lateral patellar tenderness on physical

examination. Patients with severe medial or

central patellofemoral degeneration or isolated

patellofemoral articular cartilage defects were

excluded. Pre-operative radiographs and

International Knee Society (IKS) outcome

scores were obtained for all patients [17].

Prosthesis

The HLS Uni Evolution (Tornier, Grenoble,

France) was utilized in all patients. The femoral

implant is symmetric and made from cobalt

chrome. This tibial component is polyethylene

without a baseplate.

Operative Technique

All operations were performed by the senior

author. The partial lateral patellar facetectomy

was performed first as previously described

[39]. With a tourniquet in place and the patient

supine, the knee was approached through a

lateral parapatellar incision.Alateral retinacular

release allowed visualization of the lateral

border of the patella without injuring the vastus

lateralis. Between 1 and 1.5cm of the lateral

border of the patella, including osteophytes and

1 to 2mm of articular cartilage were resected.

Any osteophytes on the lateral trochlea were

also resected and bone wax was applied to all

cut surfaces.

Attention was then turned to the unicompart

mental arthroplasty. A tibial tubercle osteotomy

was not routinely performed [10].

All patients received peri-operative antibiotics

(second generation cephalosprorins) and

prophylactic anti-coagulation treatment (low

molecular weight heparin). Range of motion

and isometric quadriceps exerciseswere initiated

as soon as possible and full weightbearing was

allowed the first week postoperatively.

Assessment of Results

Postoperative clinical and radiographic follow-

up was performed prospectively at 2 months,

6 months, 1 year, and every 2 years thereafter

in all patients. Any subsequent operations on

the index knee were recorded. Clinical results

were assessed with physical examination and

International Knee Society (IKS) scores [17].

Patients were also asked during clinic visits if

they were satisfied with their results.

Patellofemoral articulation was evaluated with

Kujala’s score [22]. Radiographic outcomes

were assessed by a standardized protocol at

follow-up including standing AP, lateral, and