PATHOLOGY
Lateral femoral condyle focal chondral defect
TREATMENT
Osteochondral autograft transplant
SUBMITTED BY
Brian J. Cole, MD, MBA, Rush Cartilage Restoration Center, Rush Univer- sity Medical Center, Chicago, Illinois, USA
CHIEF COMPLAINT AND
HISTORY OF PRESENT ILLNESS
This patient is a 34-year-old emergency room nurse who sustained a work-related injury following a twisting event. She heard a pop and had the immediate onset of swelling and lateral-sided right knee pain. Subsequently, she reported a catching sensation but denied any episodes of giving-way. Her symptoms have not improved with a trial of antiinflammatory medication.
PHYSICAL EXAMINATION
Height, 5ft, 4in.; weight, 1351b. She has a sUghtly antalgic gait with neutral alignment.
Her right knee has a moderate-sized effusion.
Her range of motion is 0 to 130 degrees. She is tender to palpation over the lateral femoral condyle. Meniscal findings are equivocal.
Patellofemoral joint demonstrates good track- ing with no evidence of crepitus. Her ligament examination is within normal limits.
RADIOGRAPHIC EVALUATION
Posteroanterior 45-degree flexion weight- bearing and lateral views were within normal limits (Figure C12.1). A magnetic resonance
(MRI) was obtained that was significant for a suggestion of a type II signal within the lateral meniscus but was otherwise considered normal.
SURGICAL INTERVENTION
Because of failure to respond to conservative treatment, she was indicated for arthroscopic evaluation and treatment. At the time of arthroscopy, she was noted to have an isolated chondral lesion of the lateral femoral condyle measuring approximately 12 mm by 12 mm.
This lesion was treated with a formal microfrac- ture technique (Figure C12.2). Following the microfracture, the patient was placed non- weight bearing for approximately 4 to 6 weeks and used continuous passive motion for 4 to 6h/day.
At the patient's 6-month foUow-up visit, she continued to complain of persistent activ- ity-related pain and swelling and was indicated for revision with an osteochondral autograft transplant. At arthroscopy, she had significant fibrocartilage fill of her previously microfrac- tured defect (Figure C12.3). Osteochondral autograft transplantation was performed using 9-mm and 7-mm plugs obtained from the lateral trochlear ridge (Figure C12.4). Postoperatively, the patient was placed on protected weight bearing for approximately 4 to 6 weeks and uti-
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36 Case 12
FIGURE
C12.1. Forty-five-degree flexion posteroanterior weight-bearing (A) and lateral (B) radiographs without abnormalities.
FIGURE
C12.2. Index microfracture treatment of iso- lated 12 mm by 12 mm defect of the lateral femoral condyle. Arthroscopic view of the lesion (A) before
microfracture and (B) after microfracture technique
performed with creation of vertical walls surround-
ing the defect.
Case 12
37FIGURE
C12.3. Arthroscopic view obtained 8 months after microfracture in which the defect was found to be filled with soft fibrocartilaginous tissue.
lized continuous passive motion. At 6 months, she was permitted to engage in activities as tolerated.
FOLLOW-UP
At nearly 1 year postoperatively, the patient has full range of motion, no swelling, and minimal complaints of activity-related pain.
DECISION-MAKING FACTORS
1. Index microfracture in a symptomatic patient indicated for isolated lesion less than 2cm^ as a first-line treatment.
2. Failure of primary microfracture as index treatment in a young intermediate-demand patient with a relatively small isolated defect.
3. Ability to replace fibrocartilage fill with two or fewer osteochondral autograft plugs.
FIGURE
