Arthroscopy:
The Journal of Arthroscopic
and Related Surgery
Published by Raven Press, Ltd. 0 1992 Arthroscopy
Osteochondritis
8(4):474-481
Association of North America
Dissecans of the Lateral Femoral Condyle in the Adult
John C. Garrett, M.D., Kenneth J. Kress, M.D., and Mark Mudano, M.D.
Summary: In osteochondritis
dissecans, 15% of the lesions occur in the lateral condyle. In order to understand the significance of these lesions, 27 were studied prospectively from 1983 to 1990 and compared with 20 consecutive cases of lesions of the medial femoral condyle. Lesions of the lateral femoral condyle were larger, and often comprised the entire width of a condyle and resulted in deformation of a significant segment of the femoral condyle. They lay further posteriorly and commonly were associated with mechanical symptoms including buckling or locking. A discernible clunk was unique to these lesions. In addition, lateral lesions were more fragile, often having multiple bony islands that were prone to fragmentation, making replacement difficult if not impossible. Lateral lesions occurred directly within the main force-bearing areas of the condyle, disrupting normal contact areas and possibly leading to more rapid joint deterioration once segments are lost. This has prompted concern for reinsertion of articular fragments or reconstruction with osteochondral allografts. Key Words: Osteochondritis dissecans-Osteochondral allograftArthritis-Loose body-Abrasion arthroplasty-Avascular necrosis.
followed prospectively. All were those of the senior author (J.C.G.) whose interest in OCD and transplant surgery may have resulted in an uncommonly high incidence of this disorder due to referral of cases from sources outside his practice. Cases of acute chondral fracture, chondral delamination, and osteonecrosis were eliminated from the study. The patients included 22 males and five females ages 16-46 years (mean, 25 years) at the time of the study. All exhibited physeal plate closure establishing them as adults. All lateral condylar lesions were unilateral although in one case OCD was present in the ipsilateral medial condyle as well as in the medial femoral condyle of the contralateral knee. Patients were studied clinically as to the type and frequency of symptoms. Each was examined for evidence of effusion, atrophy, condylar tenderness, and audible clicks or clunks indicative of mechanical dysfunction. The diameter of the lesions was measured roentgenographically with standard anteroposterior and lateral views. The product of these two figures was
Osteochondritis dissecans (OCD) is a rare disorder of unknown etiology. Approximately 15% of the lesions occur in the lateral femoral condyle (l), making these so rare that a general orthopaedic surgeon may evaluate only one or two within a lifetime and therefore lump them together with those of the medial condyle. However, they differ in subtle but important ways that has caused David Dandy (personal communication) to suggest that they are a distinct entity, if not because of etiology at least by virtue of their clinical behavior. In order to gain a better understanding, 27 cases of OCD of the lateral femoral condyle were studied prospectively. MATERIALS AND METHODS Twenty-seven cases of OCD of the lateral femoral condyle diagnosed between 1984 and 1991 were Address correspondence and reprint requests to Dr. J. C. Garrett, 77 Collier Road, Suite 2000, Atlanta, GA 30309, U.S.A.
474
and then subtracting the width of the medial joint space) was used as an estimate of the space necessary to fill with fibrous tissue if abrasion arthroplasty was performed or with an osteochondral allograft if transplantation was chosen instead. The number of bony islands within the lesion was noted. At follow-up, a search was made for degenerative changes as evidenced by progressive joint space narrowing, osteophyte formation, and sclerosis.
S
5-
.25 - .50
0 -.25
.50 -
Width m
Medial
L
FIG. 2. The width of the lesion compared condyle as noted on anteroposterior roentg
RESULTS The patients who averaged 25 years of age at the time of the study had an average age of onset of symptoms of 18.4 years. Only seven patients were symptomatic for < 1 year prior to diagnosis, the remainder being symptomatic for a mean average of 6.6 years. All were studied at the time when they first presented, which was coincident to the time that articular fracture had occurred or loose bodies extruded leaving craters in their wake. All 27 com-
FIG. 1. Osteochondritis dissecans of the lateral femoral condyle. Note the location of the defect in the midportion of the weight-bearing surface.
plained of pain that varied accordin activity, and interferred variously daily living and sports. Swelling the 27 patients. Buckling and locki by 19 and a complaint of recurrent, was noted in three. Examination revealed atrophy and effusion in 16. Tenderness wa a frank clunk was palpated in 12. Roentgenographically, anteropos vealed 100% of the lesions to be i of the lateral femoral condyle (Fig extended across the entire width whereas six involved only 50-75% diameter (Fig. 2). Of the 27 cases, parent joint space widening. As roentgenograph, seven were bisec tending down the posterior corte whereas 20 lay posterior to the lin these comprised the far posterior condyle, had no bony backing pos peared to have shifted posteriorly 4A and B). When measured acc sectional area, none of the lesion three were 4-8 cm2, 12 were 8-1 12-16 cm*, and two were 16 cm’ lesions had one or more discernib three had two, three had three, and more (Figs. 5 and 6). Two of the
Arthroscop
476
.I. C. GARRETT
ET AL. were compared roentogenographically with 20 consecutive cases of the medial femoral condyle. All of the lesions of the medial condylar were marginal in location with their epicenter in the lateral aspect of the condyle (Fig. 8A). Only one of the 20 involved
The Journal of Arthroscopic
and Related Surgery
Published by Raven Press, Ltd. 0 1992 Arthroscopy
Osteochondritis
8(4):474-481
Association of North America
Dissecans of the Lateral Femoral Condyle in the Adult
John C. Garrett, M.D., Kenneth J. Kress, M.D., and Mark Mudano, M.D.
Summary: In osteochondritis
dissecans, 15% of the lesions occur in the lateral condyle. In order to understand the significance of these lesions, 27 were studied prospectively from 1983 to 1990 and compared with 20 consecutive cases of lesions of the medial femoral condyle. Lesions of the lateral femoral condyle were larger, and often comprised the entire width of a condyle and resulted in deformation of a significant segment of the femoral condyle. They lay further posteriorly and commonly were associated with mechanical symptoms including buckling or locking. A discernible clunk was unique to these lesions. In addition, lateral lesions were more fragile, often having multiple bony islands that were prone to fragmentation, making replacement difficult if not impossible. Lateral lesions occurred directly within the main force-bearing areas of the condyle, disrupting normal contact areas and possibly leading to more rapid joint deterioration once segments are lost. This has prompted concern for reinsertion of articular fragments or reconstruction with osteochondral allografts. Key Words: Osteochondritis dissecans-Osteochondral allograftArthritis-Loose body-Abrasion arthroplasty-Avascular necrosis.
followed prospectively. All were those of the senior author (J.C.G.) whose interest in OCD and transplant surgery may have resulted in an uncommonly high incidence of this disorder due to referral of cases from sources outside his practice. Cases of acute chondral fracture, chondral delamination, and osteonecrosis were eliminated from the study. The patients included 22 males and five females ages 16-46 years (mean, 25 years) at the time of the study. All exhibited physeal plate closure establishing them as adults. All lateral condylar lesions were unilateral although in one case OCD was present in the ipsilateral medial condyle as well as in the medial femoral condyle of the contralateral knee. Patients were studied clinically as to the type and frequency of symptoms. Each was examined for evidence of effusion, atrophy, condylar tenderness, and audible clicks or clunks indicative of mechanical dysfunction. The diameter of the lesions was measured roentgenographically with standard anteroposterior and lateral views. The product of these two figures was
Osteochondritis dissecans (OCD) is a rare disorder of unknown etiology. Approximately 15% of the lesions occur in the lateral femoral condyle (l), making these so rare that a general orthopaedic surgeon may evaluate only one or two within a lifetime and therefore lump them together with those of the medial condyle. However, they differ in subtle but important ways that has caused David Dandy (personal communication) to suggest that they are a distinct entity, if not because of etiology at least by virtue of their clinical behavior. In order to gain a better understanding, 27 cases of OCD of the lateral femoral condyle were studied prospectively. MATERIALS AND METHODS Twenty-seven cases of OCD of the lateral femoral condyle diagnosed between 1984 and 1991 were Address correspondence and reprint requests to Dr. J. C. Garrett, 77 Collier Road, Suite 2000, Atlanta, GA 30309, U.S.A.
474
and then subtracting the width of the medial joint space) was used as an estimate of the space necessary to fill with fibrous tissue if abrasion arthroplasty was performed or with an osteochondral allograft if transplantation was chosen instead. The number of bony islands within the lesion was noted. At follow-up, a search was made for degenerative changes as evidenced by progressive joint space narrowing, osteophyte formation, and sclerosis.
S
5-
.25 - .50
0 -.25
.50 -
Width m
Medial
L
FIG. 2. The width of the lesion compared condyle as noted on anteroposterior roentg
RESULTS The patients who averaged 25 years of age at the time of the study had an average age of onset of symptoms of 18.4 years. Only seven patients were symptomatic for < 1 year prior to diagnosis, the remainder being symptomatic for a mean average of 6.6 years. All were studied at the time when they first presented, which was coincident to the time that articular fracture had occurred or loose bodies extruded leaving craters in their wake. All 27 com-
FIG. 1. Osteochondritis dissecans of the lateral femoral condyle. Note the location of the defect in the midportion of the weight-bearing surface.
plained of pain that varied accordin activity, and interferred variously daily living and sports. Swelling the 27 patients. Buckling and locki by 19 and a complaint of recurrent, was noted in three. Examination revealed atrophy and effusion in 16. Tenderness wa a frank clunk was palpated in 12. Roentgenographically, anteropos vealed 100% of the lesions to be i of the lateral femoral condyle (Fig extended across the entire width whereas six involved only 50-75% diameter (Fig. 2). Of the 27 cases, parent joint space widening. As roentgenograph, seven were bisec tending down the posterior corte whereas 20 lay posterior to the lin these comprised the far posterior condyle, had no bony backing pos peared to have shifted posteriorly 4A and B). When measured acc sectional area, none of the lesion three were 4-8 cm2, 12 were 8-1 12-16 cm*, and two were 16 cm’ lesions had one or more discernib three had two, three had three, and more (Figs. 5 and 6). Two of the
Arthroscop
476
.I. C. GARRETT
ET AL. were compared roentogenographically with 20 consecutive cases of the medial femoral condyle. All of the lesions of the medial condylar were marginal in location with their epicenter in the lateral aspect of the condyle (Fig. 8A). Only one of the 20 involved
