Citations

Objectives: Osteochondritis dissecans (OCD) is a disorder of subchondral bone that commonly affects the knee.The purpose of this study is to (1) evaluate the rate of arthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated non-operatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. Methods: 86 patients (mean age 21.4 years) with OCD lesions treated nonoperatively were identified between 1976 and 2014. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to arthritis was obtained from the medical record. Factors predictive of arthritis and arthroplasty (age, gender, body mass index, and lesion location) were examined. Results: At a mean follow-up of 12.6 (±9.8) years from diagnosis, 13 patients (15%) were diagnosed with arthritis corresponding to a cumulative incidence of 5.0% at 5 years, 10.0% at 10 years, 20.0% at 25 years, and 30.0% at 35 years. The cumulative incidence of arthroplasty was 1.0% at 5 years, 3.0% at 10 years, 8.0% at 25 years, and 8.0% at 35 years. BMI greater than 25 kg/m 2 (HR 15.4, 95% CI: 1.9, 124.5) and patellar OCD lesions (HR 15.0, 95% CI: 1.3, 345.3) were associated with arthritis. Conclusion: Arthritis following nonoperative treatment of OCD lesions is a challenging problem with an estimated 30% cumulative incidence at 35 years after diagnosis. In contrast, the long-term rate of arthroplasty is low. BMI greater than 25 kg/m 2 and patellar OCD lesions are predisposing factors for arthritis. Older age at diagnosis was associated with a greater risk of arthritis and knee arthroplasty.

Objectives: Osteochondritis dissecans (OCD) is a disorder of subchondral bone that causes adverse effects on the overlying cartilage and commonly affects the knee. The purpose of this study is to (1) evaluate the rate of arthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated operatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. Methods: 221 patients (mean age 26.1 ± 13.6 years) with OCD lesions treated operatively were identified between 1976 and 2014 and followed for a mean of 16.3 (±11.4) years from diagnosis. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to arthritis was obtained from the medical record. Surgical treatment was classified as palliative (fragment excision) or restorative (lesion drilling, fragment fixation, osteochondral allograft or autograft). Factors predictive of arthritis and arthroplasty were examined. Results: In the palliative group, the cumulative incidence of arthritis was 12.0% at 5 years, 17.0% at 10 years, 26.0% at 15 years, 39.0% at 20 years, and 70% at 30 years. The cumulative incidence of arthroplasty was 2.0% at 5 years, 4.0% at 10 years, 4.0% at 15 years, 10.0% at 20 years, and 32.0% at 30 years. In the restorative group, the cumulative incidence of arthritis was 3.0% at 5 years, 7.0% at 10 years, 16.0% at 15 years, 25.0% at 20 years, and 51% at 30 years. The cumulative incidence of arthroplasty was 0.0% at 5 years, 0.0% at 10 years, 3.0% at 15 years, 6.0% at 20 years, and 11.0% at 30 years. BMI greater than 25 kg/m 2 (HR 3.3, 95% CI: 1.6, 7.0), older age at diagnosis (HR 4.9, 95% CI: 1.8, 17.3) and fragment excision (HR 2.3, 95% CI: 1.2, 4.6) were predictive of arthritis. Conclusion: OCD patients treated with fragment excision have a high rate of arthritis and knee arthroplasty at long-term follow-up. In contrast, patients treated with fragment repair or osteochondral restoration have lower rates of arthritis and arthroplasty. BMI greater than 25 kg/m 2 , older age at diagnosis, and fragment excision were predictive of arthritis.

Objectives: Patellar dislocation can occur in isolation or be associated with chronicinstability. The goals of this study are to describe the rate and factors associated with additional patellar instability events (ipsilateral recurrence and contralateral dislocation), as well as the incidence of patellofemoral arthritis among skeletally immature patients following patellar dislocation. Methods: The study included a population-based cohort of 232 skeletally immature patients who experienced a first-time lateral patellar dislocation between 1990 and 2010. A chart review was performed to collect information related to the initial injury, treatment, and outcomes. Subjects were followed for a mean of 12.1 years to determine the rate of subsequent patellar dislocation (ipsilateral recurrence or contralateral dislocation) as well as clinically significant patellofemoral arthritis. Results: 104 patients had ipsilateral recurrent patellar dislocation. The cumulative incidence of recurrent dislocation was 11% at 1 year, 21.1% at 2 years, 37.0% at 5 years, 45.1% at 10 years, 54.0 % at 15 years, and 54.0% at 20 years. Patella alta (HR: 10.6, 95% CI: 3.6, 36.1), increased TT-TG distance (HR 18.7, 95% CI: 1.7, 228.2), and trochlear dysplasia (HR 23.7, 95% CI: 1.0, 105.2) were associated with recurrence. Similarly, 18 patients (7.8%) had contralateral patellar dislocation. The cumulative incidence of patellofemoral arthritis was 0% at 2 years, 1.0% at 5 years,2.0% at 10 years, 10.1% at 15 years, 17%% at 20 years, and 39.0% at 25 years. Osteochondral injury was associated with arthritis (HR 25.7, 95% CI: 6.2, 143.8). Conclusion: Skeletally immature patients have a high rate of recurrent patellarinstability that is associated with structural abnormalities such as patella alta and trochlear dysplasia. In contrast, the rate of subsequent contralateral dislocation is low. Osteochondral injury is associated with arthritis after patellar dislocation, but the overall incidence of symptomatic arthritis with advanced radiographic changes in pediatric patients is low at 12-year follow-up.

Background: Osteochondritis dissecans (OCD) is a disorder of subchondral bone that commonly affects the knee. Purpose: To (1) evaluate the rate of arthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated nonoperatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. Study Design: Case series; Level of evidence, 4. Methods: Eighty-six patients (mean age, 21.4 years) with OCD lesions treated nonoperatively were identified between 1976 and 2014. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to arthritis was obtained from the medical record. Factors predictive of arthritis and arthroplasty (age, sex, body mass index [BMI], and lesion location) were examined. Results: At a mean ± SD follow-up of 12.6 ± 9.8 years from diagnosis, 13 patients (15%) were diagnosed with arthritis, corresponding to a cumulative incidence of 5.0% at 5 years, 10.0% at 10 years, 20.0% at 25 years, and 30.0% at 35 years. The cumulative incidence of arthroplasty was 1.0% at 5 years, 3.0% at 10 years, 8.0% at 25 years, and 8.0% at 35 years. BMI at diagnosis greater than 25 kg/m 2 (hazard ratio [HR], 15.4; 95% CI, 1.9-124.5), patellar OCD lesions (HR, 15.0; 95% CI, 1.3-345.3), and diagnosis as an adult (HR, 21.7; 95% CI, 2.7-176.3) were factors associated with an increased risk of arthritis. Conclusion: Arthritis after nonoperative treatment of OCD lesions is a challenging problem, with an estimated 30% cumulative incidence at 35 years after diagnosis. In contrast, the long-term rate of arthroplasty is low. BMI at diagnosis greater than 25 kg/m 2 and patellar OCD lesions are predisposing factors for arthritis. Diagnosis of OCD as an adult was associated with a greater risk of arthritis.

Background: Previous studies have reported variable rates of recurrent lateral patellar instability mainly because of limited cohort sizes. In addition, there is currently a lack of information on contralateral patellar instability. Purpose: To evaluate the rate of recurrent ipsilateral patellar dislocations and contralateral patellar dislocations after a first-time lateral patellar dislocation. Additionally, risk factors associated with recurrent dislocations (ipsilateral or contralateral) and time to recurrence were investigated. Study Design: Cohort study; Level of evidence, 3. Methods: This population-based study included 584 patients with a first-time lateral patellar dislocation occurring between 1990 and 2010. A retrospective review was conducted to gather information about the injury, subsequent dislocations (ipsilateral or contralateral), and structural characteristics including trochlear dysplasia, patella alta, and tibial tubercle to trochlear groove (TT-TG) distance. Risk factors were assessed to delineate associations with subsequent dislocations and time to recurrence. Results: At a mean follow-up of 12.4 years, 173 patients had ipsilateral recurrence, and 25 patients had a subsequent contralateral dislocation. At 20 years, the cumulative incidence of ipsilateral recurrence was 36.0%, while the cumulative incidence of contralateral dislocations was 5.4%. Trochlear dysplasia (odds ratio [OR], 18.1), patella alta (OR, 10.4), age <18 years at the time of the first dislocation (OR, 2.4), elevated TT-TG distance (OR, 2.1), and female sex (OR, 1.5) were associated with recurrent ipsilateral dislocations. Time to recurrence was significantly decreased in patients with trochlear dysplasia (23.0 months earlier time to recurrence; P < .001), elevated TT-TG distance (18.5 months; P < .001), patella alta (16.4 months; P = .001), and age <18 years at the time of the first dislocation (15.4 months; P < .001). Risk factors for subsequent contralateral dislocations included patella alta and trochlear dysplasia. Conclusion: At 20 years after a first-time lateral patellar dislocation, the cumulative incidence of recurrent ipsilateral patellar dislocations was 36.0%, compared with 5.4% for contralateral dislocations. Trochlear dysplasia, elevated TT-TG distance, patella alta, age <18 years at the time of the first dislocation, and female sex were associated with ipsilateral recurrence. Trochlear dysplasia, elevated TT-TG distance, patella alta, and age <18 years at the time of the first dislocation were predictive of a statistically significant decrease in time to recurrence.

Background: Osteochondritis dissecans (OCD) is a disorder of subchondral bone that causes adverse effects on the overlying cartilage and commonly affects the knee. The incidence of OCD and its long-term effect on the knee joint are controversial. Hypothesis/Purpose: The purpose of this study was to (1) evaluate the rate of osteoarthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated operatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. The investigators hypothesized that OCD lesions diagnosed after skeletal maturity and treatment with fragment excision would be predictive of a diagnosis of osteoarthritis. Study Design: Cohort study; Level of evidence, 3. Methods: The investigators identified 221 patients (mean ± SD age, 26.1 ± 13.6 years) with OCD lesions treated operatively between 1976 and 2010 and followed for 16.3 ± 11.4 years (mean ± SD) from diagnosis. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to osteoarthritis was obtained from the medical record. Surgical treatment was classified as fragment excision, fragment preservation (lesion drilling and/or fragment fixation), or chondral defect grafting (osteochondral allograft or autograft). Factors predictive of osteoarthritis and arthroplasty were examined. Results: There were 134 patients in the fragment excision group, 78 patients in the fragment preservation group, and 9 patients in the chondral defect grafting group. In the fragment excision group, the cumulative incidence of osteoarthritis was 12.0% at 5 years, 17.0% at 10 years, 26.0% at 15 years, 39.0% at 20 years, and 70% at 30 years. The cumulative incidence of arthroplasty was 2.0% at 5 years, 4.0% at 10 years, 4.0% at 15 years, 10.0% at 20 years, and 32.0% at 30 years. In the fragment preservation group, the cumulative incidence of osteoarthritis was 3.0% at 5 years, 7.0% at 10 years, 16.0% at 15 years, 25.0% at 20 years, and 51% at 30 years. The cumulative incidence of arthroplasty was 0.0% at 5 years, 0.0% at 10 years, 3.0% at 15 years, 6.0% at 20 years, and 11.0% at 30 years. No patients in the chondral defect grafting group developed osteoarthritis or underwent arthroplasty. Body mass index (BMI) greater than 25 kg/m 2 (hazard ratio [HR] 3.3; 95% CI, 1.6-7.0), older age at diagnosis (HR 4.9; 95% CI, 1.8-17.3), and fragment excision (HR 2.3; 95% CI, 1.2-4.6) were predictive of osteoarthritis. Conclusion: OCD patients treated with fragment excision have a high rate of osteoarthritis and knee arthroplasty at long-term follow-up. In contrast, patients treated with fragment preservation or chondral defect grafting have lower rates of osteoarthritis and arthroplasty. BMI greater than 25 kg/m 2 , older age at diagnosis, and fragment excision were predictive of osteoarthritis.

Background: The rate of patellofemoral arthritis after lateral patellar dislocation is unknown. Purpose/Hypothesis: The purpose of this study was to compare the risk of patellofemoral arthritis and knee arthroplasty between patients who experienced a lateral patellar dislocation and matched individuals without a patellar dislocation. Additionally, factors predictive of arthritis after patellar dislocation were examined. The hypothesis was that the rate of arthritis is likely higher among patients who experience a patellar dislocation compared with those who do not. Study Design: Cohort study; Level of evidence, 3. Methods: In this study, 609 patients who had a first-time lateral patellar dislocation between 1990 and 2010 were compared with an age- and sex-matched cohort of patients who did not have a patellar dislocation. Medical records were reviewed to collect information related to the initial injury, recurrent dislocation, treatment, and progression to clinically significant patellofemoral arthritis (defined as symptoms with degenerative changes on patellar sunrise radiographs). Factors associated with arthritis (age, sex, recurrence, osteochondral injury, trochlear dysplasia) were examined. Results: At a mean follow-up of 12.3 ± 6.5 years from initial dislocation, 58 patients (9.5%) in the dislocation cohort were diagnosed with patellofemoral arthritis, corresponding to a cumulative incidence of arthritis of 1.2% at 5 years, 2.7% at 10 years, 8.1% at 15 years, 14.8% at 20 years, and 48.9% at 25 years. In the control cohort, 8 patients (1.3%) were diagnosed with arthritis, corresponding to a cumulative incidence of arthritis of 0% at 5 years, 0% at 10 years, 1.3% at 15 years, 2.9% at 20 years, and 8.3% at 25 years. Therefore, patients who experienced a lateral patellar dislocation had a significantly higher risk of developing arthritis (hazard ratio [HR], 7.8; 95% CI, 3.9-17.6; P < .001) than individuals without a patellar dislocation. However, the risk of knee arthroplasty was similar between groups (HR, 2.8; 95% CI, 0.6-19.7; P = .2). Recurrent patellar dislocations (HR, 4.5; 95% CI, 1.6-12.6), osteochondral injury (HR, 11.3; 95% CI, 5.0-26.6), and trochlear dysplasia (HR, 3.6; 95% CI, 1.3-10.0) were associated with arthritis after patellar dislocation. Conclusion: Patellar dislocation is a significant risk factor for patellofemoral arthritis, as nearly half of patients have symptoms and radiographic changes consistent with arthritis at 25 years after lateral patellar dislocation. Osteochondral injury, recurrent patellar instability, and trochlear dysplasia are associated with the development of arthritis.

Background: The cases of patients with medial compartment osteoarthritis who were ≤55 years old and had a proximal tibial osteotomy (PTO) or medial unicompartmental knee arthroplasty (UKA) were compared. Outcomes included postoperative activity level, function, and survivorship free of revision to total knee arthroplasty. Methods: Between 1998 and 2013, data were available for 240 patients between 18 and 55 years old with medial compartment arthritis and varus malalignment who were treated either with PTO (57 patients) or with UKA (183 patients). The mean age was 42.7 years for the 57 patients (41 men and 16 women) in the PTO group versus 49.2 years for the 183 patients (82 men and 101 women) in the UKA group. The Tegner activity level and Lysholm knee scores were evaluated at 3 months and at 1, 2, and 5 years postoperatively as well as at the time of the final follow-up. The end point for survival was defined as revision to total knee arthroplasty. A Wilcoxon rank-sum test was used to evaluate the difference between the groups with respect to the Tegner and Lysholm scores at the respective follow-up intervals. Multivariate regression was used to assess potential confounders. Results: Preoperatively, the PTO and UKA groups had similar Tegner (3.0 ± 1.3 and 2.6 ± 0.09, respectively) and Lysholm scores (69.5 ± 7.3 and 71.6 ± 5.4). Postoperatively, the UKA group had significantly superior mean Tegner scores compared with the PTO group at 3 months (3.82 and 2.02, respectively), at 2 years (4.33 and 3.75), and at the time of the final follow-up (4.48 and 3.08), while the Lysholm scores were higher at 3 months (88.0 and 76.3) and at the final follow-up (90.0 and 80.2) (p < 0.01 for all). Multivariate analysis showed UKA to be an independent predictor of activity level at 3 months, 1 year, and 2 years, as well as at the final follow-up. The survivorship was 77% in the PTO group at an average of 7.2 years and 94% in the UKA group at an average of 5.8 years (p < 0.01). The average time to failure was 98 months (range, 38 to 169 months) in the PTO group and 42 months (range, 2 to 123 months) in the UKA group (p < 0.01). Conclusions: In this comparative cohort study of young patients with isolated unicompartmental arthritis, those treated with UKA reached a higher level of activity early after surgery and it persisted at mid-term follow-up. The UKA group had earlier, but less frequent, revision to total knee arthroplasty. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Purpose To compare microfracture (MFX) and osteochondral autograft transfer (OAT) surgical techniques to determine (1) postoperative activity level, (2) subjective patient outcomes, (3) failure rates, and (4) assess if any lesion characteristics favored one technique over the other. Methods A comprehensive review of literature was performed of all studies comparing MFX and OAT. Studies included were all prospective studies that reported on activity‐based outcome measures such as Tegner activity scores and subjective outcomes such as the International Knee Documentation Committee score. Failure rates, as determined by the publishing authors, were recorded for each study. Meta‐analyses were conducted using a random‐effects model. Paired standardized mean differences (Hedges's g to account for small sample bias) were used for continuous outcome measures, and risk ratios (Mantel‐Haenszel method for small sample bias) for dichotomous outcome measures. Results Six prospective studies satisfied the eligibility criteria and included 249 patients (186 male, 120 female) with an average age of 26.4 years and follow‐up of 67.2 months. Tegner scores were superior in patients treated with OAT compared with MFX (ΔOAT‐MFX for pre‐post scores = 0.94 Tegner points, standardized mean difference [SMD] = 0.469, P = .005). Failure rates of MFX were higher than OAT (OAT = 11%, MFX = 32%, risk ratio = 2.42, P < .036). OAT was superior to MFX at 3 years in relation to subjective outcome scores (SMD = 0.404, P = .008). When assessing OAT lesions larger than 3 cm 2 , OAT was superior to MFX with respect to activity level (SMD = 0.506, P = .001). Conclusions OAT may achieve higher activity levels and lower risk of failure when compared with MFX for cartilage lesions greater than 3 cm 2 in the knee, although there was no significant difference for lesions less than 3 cm 2 at midterm. However, because of variability in patient‐specific factors such as age, preinjury activity level, lesion location and size, the superiority of OAT over MFX cannot be generalized to all patient populations and therefore requires individualized patient care. Level of Evidence Level II, meta‐analysis of Level I and II studies.

Objectives: Medial meniscus posterior root tears (MMPRTs) present a unique challenge for both patients and surgeons as these tears have shown to be biomechanically equivalent to complete meniscectomy. However, little is known about the natural history of these lesions. Therefore, the purpose of this study is to describe the clinical course of MMPRTs with respect to subsequent operative and non-operative treatments, and associated comorbidities. Methods: Over 2600 MRIs were identified by searching radiologist reads for the terms “root” or “root tear” from 2005-2013. Presence or absence of MMPRTs and other associated boney, meniscal, or ligamentous injuries were identified and recorded. Of these MRIs, 102 MRIs from 102 patients who had unrepaired MMPRTs with minimum 2-year follow-up and no prior ligamentous surgery were followed. These MRIs were evaluated to confirm the presence of a meniscal root tear and the presence or absence of associated meniscal or ligamentous injuries, as well as meniscal extrusion, subchondral edema, or insufficiency fractures. Chart review was performed to obtain the treatment summary after diagnosis. Radiographs from before and after the diagnosis of MMPRT were reviewed and Kellgren-Lawrence scores were determined. Finally, the association between concomitant boney, ligamentous, or meniscal injuries, patient factors, and rate of arthroplasty, as well as final Kellgren-Lawrence scores were evaluated. Chi-square analysis was used for categorical variables, and Wilcoxon Rank-Sums was used for continuous variables. Kaplan-Meier analysis was used to evaluate the effect of meniscal extrusion on the time-dependant rate of arthroplasty. Results: 104 patients (43 M:61F) were diagnosed with MMPRTs at a mean age of 54±13. These patients were followed for a mean of 66±26 months. 75 (74%) patients had associated meniscal extrusion, 64 (62%) had associated subchondral edema, and 14 (13%) had associated insufficiency fractures at the time of diagnosis. After initial diagnosis, 59 (58%) underwent subsequent surgical treatment. This included 52 (51%) patients undergoing arthroscopic partial meniscectomy, and 29 (28%) patients undergoing total knee arthroplasty at a mean 38±32 (range 3-107) months after MRI. Kellgren-Lawrence grades worsened from 1.3±0.7 before diagnosis to 2.2±1.0 after (p<0.001), with a mean 44±32 months between radiographs. There was a higher rate of radiographic arthritis (K-L grade 2+) after diagnosis (73%) than before diagnosis (36%) (p<0.001). The presence of meniscal extrusion on MRI was associated with the presence of arthritis on post-diagnosis radiographs (p=0.03). Meniscal extrusion, subchondral edema, and insufficiency fractures were not associated with increased rates of surgical treatment, or time to arthroplasty. Conclusion: Little information is available to guide patients and physicians on the clinical outcomes for MMPRTs. These injuries are associated with a relatively high rate of arthroplasty and worsening arthritis, especially with concomitant meniscal extrusion. More information is needed to determine the efficacy of meniscal root repair in preventing these unfavorable outcomes.