Operative And Non-operative Management Of Osteochondritis Dissecans In The Knee Of Skeletally Immature Patients: Rates Of Persistent Knee Pain, Osteoarthritis, And Arthroplasty At Mean 14- Years Follow-up

Abstract

Objectives:The purpose of this study was to report long-term follow-up of skeletally immature OCD lesions treated operatively and non-operatively and determine risk factors for persistent knee pain at final follow-up.Methods:A large, geographic database of over 500,000 patients was reviewed in this case series to identify and confirm patients with OCD of the knee. Presenting radiographs and MRI were reviewed. Clinical course including operative management, persistent knee pain, and conversion to TKA were obtained and analyzed through review of clinical and operative notes.Results:95 skeletally immature patients (70 males, 25 females) with OCD lesions diagnosed at a mean age of 13 years (range: 7-16) were followed for a mean of 14 years (range: 2-40). 53 patients (56%) were treated operatively and 42 patients (44%) were treated non-operatively. At final follow up, 13 patients with a mean age of 30 years noted persistent knee pain, 8 (15%) treated operatively versus 5 (12%) treated non-operatively. Risk factors for knee pain were female gender, patellar lesion location, and unstable lesions (Table 1). Four patients (8%) treated operatively and two (5%) treated non-operatively developed symptomatic osteoarthritis at a mean of 28.6 years following diagnosis. One patient treated operatively and two treated non-operatively converted to TKA at a mean of 37 years following diagnosis. Mean age at TKA was 52 years, significantly younger than that observed for primary TKA at our institution (p = 0.004).Conclusion:Patients with skeletally immature OCD lesions have an estimated 14% rate of persistent knee pain, 6% risk of symptomatic osteoarthritis, and 3% risk of conversion to TKA at a mean of 14 years following time of diagnosis. Female patients, patellar lesions, and unstable lesions demonstrated increased risk of persistent knee pain at final follow-up. Patients with OCD of the knee convert to TKA at a significantly younger age than that of the general primary TKA population.Table 1.Risk factors for penistent ;met pain at the time of final follow-up Variable HR (95% Confidence Interval) p-value Treatment Non-OperativeReference Operative1.16(0.35 - 3.83)0.81Age at diagnosis <10Reference ≥1010.3(0.11-9.63)0.98Gender FemaleReference Male0.24(0.07-0.81) 0.02 Location MFCReference LFC2.91(0.57-14.97)0.2 Patella5.30(1.37-20.48) 0.02 Trochlea0.00(0.00-0.00)a <0.01a AP Radiograph Lesion Width <20mmReference ≥20mm1.74(0.23-12.97)0.59AP Radiograph Lesion Depth <5mmReference ≥5mm0.68(0.08-6.00)0.73Lateral Radiograph Lesion Width <20mmReference ≥20mm1.75(0.31-10.01)0.53Lateral Radiograph Lesion Depth <5mmReference ≥5mm2.14(0.38-11.95)0.38Lesion Contour ConcaveReference Convex0.45(0.08-2.54)0.37Disruption of subchondral bone NoReference Yes0.73(0.15-3.54)0.7Intra-articular displace fragment NoReference Yes0.85(0.10-7.48)0.88Adjacent Focal Articular Cartilage Defects NoReference Yes0.85(0.10-7.48)0.88Stability StableReference Unstable10.58(1.26-88.63) 0.03 aOf then =2 lesions present on the trochlea, none developed symptomatic Knee pain