Femoral Condyle Lesions Research Articles

Paper 52: Association of Mechanical Axis with Osteochondritis Dissecans of the Femoral Condyle

Objectives: Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. Pathophysiology for the etiology and underlying mechanism of OCD lesion development is not fully understood. The purpose of this study was to determine the association of lower extremity weightbearing axis with femoral condyle OCD lesion location, and if this association was affected by certain patient and OCD lesion characteristics such as lesion stability, skeletal maturity, and the presence of the OCD lesion on the medial versus lateral femoral condyle. Methods: This was a retrospective case series at a single, large academic institution. The primary outcome was the association of femoral condyle OCD lesion location with lower extremity weightbearing axis as categorized by Cahill and Berg zones of the knee. Secondary outcomes included sub-group analyses (treatment, skeletal maturity, and lesion stability) and contribution of femoral and tibial mechanical axis to lower extremity weightbearing axis deviations (mechanical lateral distal femoral angle [mLDFA] and medial proximal tibial angle [MPTA]). For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. Results: Eighty-six patients and 95 knees with an OCD lesion of the femoral condyle were identified, with 9 patients (11%) having bilateral OCD lesions. There were 74% male patients with average age of 21 years old. 65% of knees had closed distal femoral physes, 82% of OCD lesions were unstable on MRI imaging, and 85% underwent a surgical procedure. Seventy-five percent of OCD lesions were located in Cahill and Berg zone 2 at the lateral aspect of the medial femoral condyle. Lower extremity mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same knee compartment in 56% of cases. Over 90% of OCD lesions were within ±1 zone of the weightbearing axis. There were no significant differences in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condyle OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condyle OCD lesions, the mean mLDFA was 89.9° and MPTA was 85.4°, whereas for valgus alignment and lateral femoral condyle lesions, the mLDFA was 84.8° and MPTA was 88.8°. Both the mLDFA and MPTA were significantly different when comparing medial to lateral femoral condyle OCD lesions (p <0.001 and <0.001, respectively). Patients with unilateral medial femoral condyle OCD lesions were more likely to have varus alignment of the affected extremity compared to the contralateral extremity (59% vs. 36%, p = 0.01). Conclusions: This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condyle OCD location. Patients with unilateral medial femoral condyle OCD lesions are more likely to have varus alignment in the affected extremity. Varus alignment associated with medial femoral condyle lesions had similar varus contributions from both femoral and tibial alignment whereas valgus alignment in the setting of lateral femoral condyle lesions appear to have predominantly femoral contributions. There were no significant differences in association with mechanical axis among medial versus lateral femoral condyle lesions, OCD lesion stability, or distal femoral physeal status. More work is required to better understand the relationship between mechanical axis and femoral condyle OCD lesion pathophysiology with the long-term goal of identifying patients at risk for progression of lesion instability and developing potential interventions to preserve articular cartilage.

Association of Mechanical Axis With Osteochondritis Dissecans of the Femoral Condyle.

Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. The role of weightbearing alignment in the pathophysiology of OCD lesion development is not fully understood. Lower extremity mechanical axis would be concordant with femoral condylar OCD lesion location. Cross-sectional study; Level of evidence, 3. Cases were identified from a single, large academic institutional database using International Classification of Diseases, Ninth Revision and Tenth Revision and Current Procedural Terminology codes associated with OCD. Patients were included if they had a magnetic resonance imaging scan demonstrating the OCD lesion and lower extremity alignment radiographs. OCD lesion location was identified using Cahill and Berg zones. The primary outcome was the association of OCD lesion location with weightbearing mechanical axis. Secondary outcomes included the association of mechanical axis with skeletal maturity, OCD lesion stability, and treatment. For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. A total of 86 patients (95 knees) with an OCD lesion of the femoral condyle were identified. The population was 74% male, and the mean age was 21 years. In total, 65% of knees had closed physes, 82% of lesions were unstable, and 85% underwent a surgical procedure. Mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same compartment in 56% of cases. Spearman correlation coefficient demonstrated a moderate positive correlation (rs = 0.59). No significant differences were found in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condylar OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condylar OCD lesions, the mean lateral distal femoral angle was 89.9°, and medial proximal tibial angle was 85.4°; for valgus alignment and lateral femoral condylar lesions, the lateral distal femoral angle was 84.8°, and medial proximal tibial angle was 88.8°. Patients with unilateral medial femoral condylar OCD lesions were more likely to have varus alignment of the affected extremity compared with the contralateral extremity (59% vs 36%; P = .01). This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condylar OCD location. Patients with unilateral medial femoral condylar OCD lesions frequently had asymmetric varus alignment in the affected extremity.

Poster 256: Is There a Difference Between Medial and Lateral Femoral Condyle Allografts? An Outcome and Survivorship Analysis

Objectives: Focal chondral and osteochondral defects in the knee are problematic and are often difficult to treat. One solution is the use of osteochondral allograft (OCA) transplantation. A majority of the literature deliberates lesions located to the medial femoral condyle (MFC), but little is discussed regarding the lateral femoral condyle (LFC). Given the limited data, the purpose of this study was to compare graft survivorship and patient-reported outcomes (PROs) among patients who underwent OCA transplantation of the MFC or LFC. Methods: A total of 208 patients who underwent primary OCA transplantation of the MFC and 111 patients who underwent primary OCA transplantation of the LFC between 1997 and 2021 were identified from a prospectively collected single-surgeon cartilage registry. Overall, 66% were male and the mean age was 30.5 years. Most patients presented for OCA for osteochondritis dissecans (57%). Mean allograft size was 6.7 cm2. All patients had a minimum 2-year follow-up. Reoperations following the OCA transplantation were captured. Failure of the allograft was defined as removal of the graft (OCA revision or conversion to arthroplasty). PROs were measured both pre and postoperatively using the Knee Injury and Osteoarthritis Outcomes Scores (KOOS), International Knee Documentation Committee (IKDC), and Merle d’Aubigné-Postel scales. Patient satisfaction was also assessed. Results: Patients with MFC grafts were older than patients with LFC grafts (33 years and 26 years respectively; p<0.001) and had a slightly higher BMI (25.6 and 24.4 respectively; p=0.039). There were no differences between groups in regard to diagnosis, sex, number of allografts transplanted, or size of the allograft. Reoperations occurred in 27.9% of patients with MFC grafts and 26.1% of patients with LFC grafts (p=0.737). OCA failure occurred in 12% of MFC grafts and 9% of LFC grafts (p=0.413). The 10-year survivorship was 88% for MFC grafts and 92.9% for LFC grafts (p=0.543) (Figure 1). Among patients who had the allograft in situ at latest follow-up, the mean follow-up duration was 9.4 years for MFC grafts and 8.6 years for LFC grafts (p=0.313). At latest follow-up, KOOS, IKDC, and Merle d’Aubigné-Postel scores were similar between patients with MFC and LFC grafts. Patients with MFC grafts reported a slightly higher rate of satisfaction compared to patients with LFC grafts (93.7% and 86.3% respectively, p=0.041). Conclusions: Little data is available comparing treatment of medial and lateral femoral condyle lesions with osteochondral allografts. Clinical perception is that LFC lesions have inferior outcome to MFC lesions, but we did not find this to be true. We found little difference in reoperation rates and survivorship, as well as patient-reported clinical outcomes as measured on the KOOS, IKDC, and Merle d’Aubigné-Postel scales. There was a small difference in patient satisfaction. We conclude that there is similar outcome when using allografts for either medial or lateral femoral condyle lesions.

Rates and predictors of reimplantation of matrix-induced autologous chondrocyte implantation following first stage cartilage harvest: A cohort study

PurposeTo assess the reimplantation rate and predictors of patients requiring second-staged matrix-induced autologous chondrocyte implantation (MACI) reimplantation after initial first stage cartilage biopsy. MethodsA retrospective review was performed from 2018 to 2022 among patients who underwent only phase I MACI biopsy procedure (biopsy group) or both phase I with transition to phase II implantation of chondrocytes (implantation group) at a single tertiary center. Demographic, qualitative, and quantitative measurements were recorded, and univariate and multivariate regression analysis was performed to assess predictors of ultimately requiring second stage MACI implantation. ResultsA total of 71 patients (51% female, age 27.7 ± 10.6 years (range 12–50)) were included in this study. Eventually, 25 of 71 patients (35.2%) experienced persistence of symptoms after initial MACI biopsy and other concomitant procedures, requiring second-stage implantation. Univariate analysis showed the implantation group compared to the biopsy group had a greater lesion size (5.2 cm2 ± 3.3 vs. 3.3 cm2 ± 1.4, p = 0.024), a higher proportion patients ≥ 26 years of age (76% vs. 43%, p = 0.009), a medial femoral condyle lesion more commonly (33% vs 11%, p = 0.005), were more often female (72% vs. 39%, p = 0.008), and had less often soft tissue repair at time of biopsy (32% vs. 61%, p = 0.020). Backward multivariate logistic regression analysis revealed that size of the lesion (OR 1.43, p = 0.031) and age ≥ 26 years old at time of biopsy (OR 3.55, p = 0.042) were independent predictors of not responding to initial surgery and requiring implantation surgery. ConclusionThis study found that 35% of patients undergoing MACI phase I biopsy harvest eventually required autologous implantation. Independent risk factors for progressing to implantation after failed initial surgery were larger defect size and older age.Level of Evidence: III, Cohort Study.

Association of Stability and Size of Unhealed Area With Failure After Internal Fixation for Osteochondritis Dissecans Lesions of the Knee: Radiological Evaluation Using Computed Tomography

Background: Open reduction and internal fixation (ORIF) has been widely performed because the osteochondral component of the osteochondritis dissecans (OCD) lesion is the most suitable for reconstructing the joint structure. Purpose: To evaluate radiological healing in terms of reconstructed bony structure after ORIF with bone graft by computed tomography (CT), to identify preoperative prognostic factors for failure, and to determine the cutoff value of radiological healing for risk of failure. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective cohort study of 42 patients (44 knees) who underwent internal fixation with bone graft for OCD lesions of the knee from 2004 to 2018 was conducted. All patients were evaluated 6 months postoperatively, and if not healed 6 months after surgery, they were evaluated by CT periodically thereafter. Radiological healing was judged according to the following 3 criteria: (1) reossification of the OCD lesion, (2) bony continuity between the OCD lesion and basal floor, and (3) reconstructed bony surface of the femoral condyle reconstructed to match the normal joint. Then, the percentage of the radiological healing area was calculated as the ratio of the healing length to the total lesion length. The nonhealing area was calculated by multiplying the sum of the total nonhealing length. Clinical failure was defined as any definitive reoperation for the same OCD lesion, such as fragment excision, or a cartilage restoration procedure. After 6 months, all eligible patients underwent arthroscopy to check for protrusion of the absorbable pin into the joint; the removal of an absorbable pin protruding into the joint was not considered a failure. Results: Clinical failure was recorded for 4 cases (9.1%). The mean overall percentage of the radiological healing area of OCD 6 months after ORIF with bone graft was 79.5% ± 24.4%, and the mean overall nonhealing area at 6 months was 87.8 ± 107.9 mm2. The percentages of radiological healing area of stable (International Cartilage Regeneration & Joint Preservation Society OCD II) lesions and femoral condylar (lateral femoral condyle + medial femoral condyle) lesions were significantly lower than unstable lesions and femoral groove lesions, respectively (P = .01 and P = .03, respectively). On receiver operating characteristic curve analysis, the cutoff points for predicting a significantly increased risk of failure were 33.9% (sensitivity, 100%; specificity, 100%; area under the curve, 1) for the percentage of radiological healing area and 222.9 mm2 (sensitivity, 95%; specificity, 100%; area under the curve, 0.956) for the nonhealing area 6 months postoperatively. Conclusion: A stable lesion and a femoral condylar lesion were the predictors of poor radiological healing on CT images 6 months after ORIF with bone graft. The risk of failure was increased significantly in cases with only approximately one-third of the lesion healed or in cases with large nonhealing areas at 6 months postoperatively.

Abnormalities of the pericruciate fat pad: Correlations with the location and severity of chondral lesions of the knee

PurposeThe aim of this study was to evaluate the relationship between the grade of signal change of the pericruciate fat pad (PCFP) and the location and severity of cartilage alterations in the knee on magnetic resonance imaging (MRI). Materials and methodsThis retrospective study included 234 patients (M:F = 96:138, mean: 51 years) who underwent knee MRI. Two experienced musculoskeletal radiologists assessed any PCFP alterations (as grades 0–3) and chondral lesions using the modified Outerbridge grade (as grades 0–4). Bone marrow lesions (BMLs), meniscal status, anterior cruciate ligament alterations, and effusion-synovitis were also evaluated on the MRI. The relationships between PCFP alteration and MR findings (including the grade of chondral lesion) were evaluated. ResultsSignal changes in the PCFP were detected in 150 cases by Reader 1 (grade 0, 67 cases; grade 1, 53 cases; grade 2, 21 cases; grade 3, 9 cases) and in 154 cases by Reader 2 (grade 0, 59 cases; grade 1, 61 cases; grade 2, 24 cases; grade 3, 10 cases). The grade of PCFP signal change was statistically significantly correlated with the grade of the chondral lesion of the medial femoral condyle (MFC) (p = 0.029 and p = 0.003, respectively) and the medial tibial plateau (MTP) (p = 0.045, p = 0.002, Readers 1 and 2, respectively). The grade of PCFP signal change was significantly correlated with the grade of the BMLs of the MFC, MTP, and lateral femoral condyle (p < 0.05) for both readers. PCFP alteration was related to effusion-synovitis and tears of the medial meniscus. ConclusionsThe grade of PCFP signal change was correlated with the severity of the cartilage alteration in the medial compartment of the knee joint and was also correlated with BMLs in the medial compartment, medial meniscal tears, and synovitis. Therefore, signal change in the PFCP seen on MRI can be an additional clue of the presence of osteoarthritis in the knee, particularly in the medial compartment.

Poster 284: Investigating the Frequency and Extent of Articular Cartilage Injury Following Patellar Dislocation: A Comparison of Recurrent vs. First-Time Dislocations

Objectives: In cases of patellar dislocation, surgical intervention is typically reserved for patients with recurrent instability, unless a chondral or osteochondral fragment is identified following the initial dislocation. There is concern that multiple dislocation events may result in a higher incidence of articular cartilage injury. The purpose of this study is to compare the incidence of articular cartilage damage in patients with a single patellar dislocation to those with multiple patellar dislocations, and secondarily to compare the location and severity of chondral injury between the groups. Methods: Patients diagnosed with patellar dislocation were retrospectively identified by ICD-9 &amp; ICD-10 codes from 2017-2021. Inclusion criteria were patients with a documented history of patellar dislocation with an MRI of the affected knee available for review. Patients with articular cartilage injury prior to dislocation event were excluded. Medical records were reviewed to determine the number of previous patellar dislocations. Articular cartilage injury was graded using a validated system, AMADEUS (mean total Area Measurement And DEpth &amp; Underlying Structures, a scale from 0 to 100; 100 = no injury). Parametric continuous data was calculated by performing t tests. Nonparametric continuous data was calculated by performing Mann-Whitney tests. Chi-Square or Fisher’s Exact tests were used to calculate p values for categorical data. Results: After chart and imaging review, 233 patients were included: 117 with a primary dislocation and 116 with recurrent dislocations. Fifty-one (43.6%) of the primary dislocations and 68 (58.6%) of the recurrent dislocations were found to have articular cartilage injuries (p=0.068). When comparing the primary and recurrent groups, there was no difference in age, BMI, race, or laterality, but the recurrent group contained a significantly larger proportion of females (46.2% vs. 65.5%, P=0.004). There was no difference in lesion size, subchondral bone defect, presence of bone edema, or total AMADEUS score between groups (p=0.231). Subgroup analysis revealed that when cartilage damage is present, patients from the primary group had significantly more full-thickness lesions (p&lt;0.001) and lower AMADEUS scores (p=0.016). The primary group had an increased proportion of medial facet and lateral femoral condyle lesions (p=0.026). Conclusions: There is a high percentage of cartilage injury in patients with a history of primary and recurrent patellar instability, with 43.6% and 58.6% of patients respectively, showing articular cartilage injury on MRI. Chondral injury primarily affected the medial and lateral patellar facets, and the lateral femoral condyle in both the primary and recurrent dislocation groups. However, the primary group demonstrated an increased number of full thickness lesions and subchondral bone defects. There was no difference in lesion size, presence of bone edema, or total AMADEUS score between the primary and recurrent groups. [Table: see text][Table: see text]

Knee Injury-Baseball

HISTORY: A 19yo male college baseball pitcher presented for acute onset left medial knee pain after attempting to carry a couch, at which time he twisted the knee into a valgus position and felt a painful pop. He had mild difficulty with weight bearing and swelling. He questioned whether he may have dislocated the kneecap with spontaneous reduction. He denied associated bruising, instability, hip or back pain. He denied prior knee injury. He did report mild chronic groin pain during pitching which was unchanged. PHYSICAL EXAMINATION: There was mild effusion about the left knee, with tenderness at the medial joint line and near the proximal origin of the MCL. There was pain with valgus stress, without clear laxity. Varus stress was non-provocative. Anterior and posterior drawer test were limited secondary to guarding. Lachman's test was equivocal. McMurray's test was positive for pain. Patellar apprehension was positive. Patellar grind was negative. Straight leg test was negative. Distal neurovascular exam was grossly intact. DIFFERENTIAL DIAGNOSIS: Lateral patellar dislocation/subluxation. ACL or MCL sprain/tear. Traumatic medial meniscus tear. Osteochondral lesion of the medial femoral condyle. Muscle or tendon sprain/tear. TEST AND RESULTS: Left knee X-ray was negative for fracture and showed normal alignment. Left knee MRI revealed nonspecific edema throughout the deep soft tissues of the posterior distal thigh and knee, most pronounced along the posteromedial aspect of the distal femoral metaphysis near the insertion of the adductor magnus tendon. Findings were suggestive of acute on chronic partial tearing/avulsion injury of the distal adductor magnus with an adjacent focus of mineralization consistent with underlying calcific tendinosis. The cruciate and collateral ligaments were intact. There were no findings suggestive of transient lateral patellar dislocation. FINAL WORKING DIAGNOSIS: Calcific tendinosis of the adductor magnus tendon, with superimposed traumatic avulsion injury/partial tearing TREATMENT AND OUTCOMES: The patient was allowed to weight bear as tolerated but was instructed to abstain from lower body exercise for 4 weeks. NSAIDs were used for pain relief as needed. He was referred to PT at 4 weeks with a focus on pitching mechanics.

Osteochondral Allograft Transplantation for Focal Cartilage Defects of the Femoral Condyles.

Osteochondral allograft transplantation requires meticulous planning, beginning with preoperative radiographs to evaluate the patient's alignment, estimate the lesion size, and aid in matching of a donor femoral condyle. The procedure begins with the patient supine and the knee flexed. A standard arthrotomy incision is performed on the operative side. Once exposure is obtained, a bore is utilized to remove host tissue from the lesion typically to a depth of 5 to 8 mm. Measurements are taken and the donor condyle is appropriately sized to match. A coring reamer is utilized to create the plug from donor tissue, which is trimmed to the corresponding depth. After marrow elements are removed via pulse lavage, the allograft plug is placed within the femoral condyle lesion through minimal force. Nonoperative treatment involves a reduction in high-impact activities and physical therapy. Surgical alternatives include chondroplasty, microfracture, and osteochondral autograft transplantation; however, these options are typically performed for smaller lesions (<2 cm). For larger lesions (≥2 cm), matrix-induced autologous chondrocyte implantation (MACI) can be utilized, but requires 2 surgical procedures. Osteochondral allograft transplantation is selected against other procedures for various reasons related to patient goals, preferences, and expectations. Typically, this procedure is favored over microfracture or autograft transplantation when the patient has a large lesion. Allograft transplantation might be favored over MACI because of patient preference for a single surgical procedure instead of 2. To our knowledge, there are currently no Level-I or II trials comparing osteochondral allograft transplantation against other treatments for cartilage defects. There are, however, many systematic reviews of case studies and cohorts that report on outcomes. A 2016 review of 291 patients showed significantly improved patient-reported outcomes at a mean follow-up of 12.3 years5,9. The mean survival of grafts was 94% at 5 years and 84% at 10 years5. Overall, data on long-term survival are lacking because interest in and use of this procedure have only increased over the past few decades10. Finally, the rate of return to sport is promising, with the systematic review by Campbell et al. showing rates as high as 88% with an average time to return to sport of 9.6 months11. Postoperatively, patients can expect to immediately begin passive range of motion. Progression of heel-touch weight-bearing begins at 6 weeks, and patients may return to sport-specific activity after 8 months, as tolerated. Ensure that the allograft is of adequate quality and is size-matched prior to performing the surgical procedure.The cannulated cylinder should be perpendicular to both the host lesion and graft tissue in order to ensure symmetric estimations of size.Save subchondral bone shavings when preparing the host lesion. These can be utilized to take up space if your graft depth is not sufficient to fill the host defect.Utilize saline solution irrigation judiciously when reaming out the host tissue and graft plug. AAROM = active-assisted range of motionACI = autologous chondrocyte implantationAP = anteroposteriorBMI = body mass indexCPM = continuous passive range of motionGlut/glutes = gluteal musclesHTO = high tibial osteotomyICRS = International Cartilage Repair SocietyLFC = lateral femoral condyleLTP = lateral tibial plateauMACI = matrix-induced autologous chondrocyte implantationMFC = medial femoral condyleMobs = mobilizationMRI = magnetic resonance imagingNSAIDs = non-steroidal anti-inflammatory drugsOAT = osteochondral allograft transplantationPROM = passive range of motionQuad = quadriceps musclesROM = range of motionSLR = straight leg raise.

Factors associated with acute articular cartilage lesions of the patella and lateral femoral condyle in acute first-time lateral patellar dislocation: A prospective magnetic resonance imaging study

ObjectivesTo identify risk factors of acute articular cartilage lesions of the patella and lateral femoral condyle in acute first-time lateral patellar dislocation (LPD). MethodsMagnetic resonance images were prospectively analyzed in 115 patients in an acute first-time LPD. Factors included gender, skeletal maturity, trochlear dysplasia, patellar height, and tibial tuberosity–trochlear groove (TT-TG) distance. Binary logistic regression analysis was carried out to identify the independent risk factors for the incidence of acute articular cartilage lesions of the patella and lateral femoral condyle in acute first-time LPD. ResultsThe incidence of acute articular cartilage lesion of the patella and lateral femoral condyle were 46.1% and 27% in acute first-time LPD, respectively. Univariate analysis revealed significantly higher incidence rate of acute articular cartilage lesion of the patella in male (P = 0.027), skeletally mature (P = 0.035), normal TT-TG distance (P = 0.043) and normal femoral trochlea (P = 0.031). Risk factors for the incidence of acute articular cartilage lesion of the patella were skeletally mature (odds ratio (OR): 2.324), normal TT-TG distance (OR: 2.824) and normal femoral trochlea (OR: 3.835). Univariate analysis revealed significantly higher incidence rate of acute articular cartilage lesion of the lateral femoral condyle in skeletally mature (P = 0.027) and normal femoral trochlea (P = 0.031). Risk factor for the incidence of acute articular cartilage lesion of the lateral femoral condyle was normal femoral trochlea (OR: 3.347). ConclusionsFor patients in acute first-time LPD, compared with other parameters, the normal femoral trochlea, normal TT-TG distance and skeletally mature are independent risk factors for the incidence of acute articular cartilage lesion of the patella, and the normal femoral trochlea is an independent risk factor for the incidence of acute articular cartilage lesion of the lateral femoral condyle.

Arthroscopic Drilling for Stable Juvenile Osteochondritis Dissecans of the Knee Is Safe and Patients Reliably Return to Daily Activities by 3 Months

PurposeTo assess the postoperative timeline for the return to activities of daily living (ADLs) in pediatric patients after arthroscopic drilling of a stable osteochondritis dissecans (OCD) lesion of the knee and to determine the rate of and risk factors for complications after the procedure.MethodsIn a retrospective chart review, data from all patients aged 18 years or younger who underwent arthroscopic drilling for a stable OCD lesion of either femoral condyle from May 2009 through July 2017 were collected. Demographic data, lesion characteristics, operative data, postoperative course, radiographic outcomes, and complications were recorded. Statistical analysis was performed to determine the risk factors for reoperations.ResultsA total of 139 knees in 131 patients were evaluated, with a mean age of 12.7 years, of which 102 (73%) were male knees. The average follow-up period was 17.8 ± 13.2 months after surgery. All patients regained full extension and flexion within 5° of the contralateral knee at a mean of 12.9 ± 3.2 weeks postoperatively, with 95% having returned fully to ADLs by the 3-month postoperative visit. No cases of infection, stiffness, arthrofibrosis, or other procedure-related complications were recorded. A total of 133 knees (95.7%) showed healing on radiographs, whereas 6 knees (4.3%) underwent additional surgical procedures, all of which were performed for treatment failure related to nonhealing lesions (including loose body removal, chondroplasty, and repeated drilling). Lesion size was the only significant risk factor for reoperation (P = .02).ConclusionsOur findings suggest that arthroscopic drilling for stable, intact OCD lesions in the pediatric knee is a safe procedure with reliable outcomes and return to ADLs and a minimal risk of complications. Most patients return to their preoperative daily activity level with a full range of motion of the knee by 3 months after surgery. Complications, including reoperations, are related to the progression of the OCD lesion rather than to the surgical procedure. Each 1-cm2 increase in lesion size increases the likelihood of reoperation by 2.93 times.Level of EvidenceLevel IV, therapeutic case series.

Differences in Clinical and Functional Outcomes Between Osteochondral Allograft Transplantation and Autologous Chondrocyte Implantation for the Treatment of Focal Articular Cartilage Defects.

Background:Articular cartilage pathology can result from a spectrum of origins, including trauma, osteochondritis dissecans, avascular necrosis, or degenerative joint disease.Purpose:To compare the differences in clinical and patient-reported outcomes after autologous chondrocyte implantation (ACI) versus osteochondral allograft transplantation (OCA) in patients with focal articular cartilage defects without underlying bone loss.Study Design:Cohort study; Level of evidence, 3.Methods:A retrospective review identified patients who underwent ACI or OCA between 2008 and 2016 for isolated grades 3 and 4 articular cartilage defects without underlying bone loss. Outcome measures included the Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), International Knee Documentation Committee (IKDC) evaluation, and 12-Item Short Form Health Survey–Physical Component (SF-12-P) scores. Defect location, size, complications, and rate of subsequent surgery were determined.Results:Overall, 148 patients were included: 82 (55%) underwent ACI and 66 (45%) underwent OCA. The mean age at the time of surgery was 31.2 years within the ACI cohort and 37.7 years within the OCA cohort (P < .001); the mean follow-up for both cohorts was 6.7 years (P = .902). Within the ACI group, 28 (34%) patients had multifocal defects, 21 (26%) had defects confined to the femoral condyles, and 33 (40%) had defects in the patellofemoral region. Within the OCA group, 23 (35%) patients had multifocal defects, 30 (46%) had confined femoral condyle lesions, and 13 (20%) had patellofemoral defects. When comparing by lesion location, there were no significant differences in KOOS JR, and IKDC scores between the ACI and OCA cohorts (P < .05). There was, however, a significant difference for SF-12-P scores for FDD trochlear lesions. In both cohorts, traumatic patellofemoral pathology demonstrated lower patient-reported outcomes and higher failure rates than degenerative lesions. The overall rate of failure, defined as graft failure with revision surgery and/or conversion to arthroplasty, was significantly greater in the OCA group (21% vs 4%; P = .002).Conclusion:Study results indicated that ACI provides similar outcomes to OCA with or without concomitant procedures for the treatment of symptomatic articular cartilage defects in all lesion locations and may have a lower revision rate for multifocal and condylar lesions.

Incidence of Subsequent Surgical Intervention at Short-term Follow-up in Previously Healing and Stable Juvenile Osteochondritis Dissecans of the Knee.

Juvenile osteochondritis dissecans (OCD) of the knee is a defect of subchondral bone seen primarily in active children and adolescents. Studies have evaluated the incidence of surgery in knee OCD, but the incidence of subsequent surgery in patients with stable, healing lesions cleared to return to activities is unknown. This study sought to determine the incidence of surgery in participants with knee OCD lesions cleared to return to activities and evaluate predictors of subsequent surgery. A single center, retrospective review was performed of participants aged 7 to 18 with knee OCD. Inclusion criteria were stable lesion, skeletal immaturity, no history of previous knee surgery, release to activity without surgery, and at least 12 months of follow-up. Documentation of subsequent surgery was queried in the electronic health record. Participants with no recorded surgery were contacted through phone. Analysis included bivariate and logistic regression. Twenty-five individuals were included in this study, with 7 undergoing surgery after returning to activity. Medial femoral condyle lesions were less likely to undergo surgery (B=-2.6, P=0.038). Average lesion size for the Surgery and No Surgery groups was 1.76±0.65 and 1.32±0.81 cm2, respectively, though not significantly different (P=0.21). The Surgery group returned to activity sooner (3.7 mo, range 1.1 to 6.4) than the No Surgery group (8.1 mo, range 1.8 to 35.4), though not significantly different (P=0.18). Mean follow-up time for the study was 42.7 (range 12.6 to 77.6) months. No participants contacted by phone progressed to surgery or reported symptoms that limited their activities. While the majority of participants with stable, healing, and asymptomatic knee OCD lesions have favorable outcomes with nonoperative management, some lesions may progress to surgery. Lesions on the medial femoral condyle may be predictive of lower likelihood of progression to surgery. Our study provides insight on the outcomes of nonoperative management of OCD lesions. Level IV-prognostic study.

Rehabilitation Variability Following Femoral Condyle and Patellofemoral Microfracture Surgery of the Knee.

To assess the variability of postoperative rehabilitation protocols used by orthopedic surgery residency programs for microfracture of femoral condyle and patellofemoral lesions of the knee. Online postoperative microfracture rehabilitation protocols from US orthopedic programs and the scientific literature were reviewed. A custom scoring rubric was developed to analyze each protocol for the presence of discrete rehabilitation modalities and the timing of each intervention. A total of 18 programs (11.6%) from 155 US academic orthopedic programs' published online protocols and a total of 44 protocols were analyzed. Seventeen protocols (56.7%) recommended immediate postoperative bracing for femoral condyle lesions and 17 (89.5%) recommended immediate postoperative bracing for patellofemoral lesions. The average time to permitting weight-bearing as tolerated (WBAT) was 6.1 weeks (range, 0-8) for femoral condyle lesions and 3.7 weeks (range, 0-8 weeks) for patellofemoral lesions. There was considerable variation in the inclusion and timing of strength, proprioception, agility, and pivoting exercises. For femoral condyle lesions, 10 protocols (33.3%) recommended functional testing prior to return to sport at an average of 23.3 weeks postoperatively (range, 12-32 weeks). For patellofemoral lesions, 4 protocols (20.0%) recommended functional testing for return to sport at an average of 21.0 weeks postoperatively (range, 12-32 weeks). A minority of US academic orthopedic programs publish microfracture rehabilitation protocols online. Among the protocols currently available, there is significant variability in the inclusion of specific rehabilitation components and timing of many modalities. Evidence-based standardization of elements of postoperative rehabilitation may help improve patient care and subsequent outcomes.

Osteochondral Allograft Transplantation for Osteochondritis Dissecans of the Medial Femoral Condyle

Background: While the data are not as robust as in the adult population, osteochondral allograft transplantation has proven to be an effective treatment for osteochondritis dissecans (OCD) lesions of the knee in the pediatric and adolescent populations. Indications: The primary indication for osteochondral allograft transplantation is a symptomatic, full-thickness, localized cartilage lesion. Acceptable underlying causes include trauma, avascular necrosis, and OCD lesions. As these are pediatric and adolescent patients, they are not candidates for joint arthroplasty. In this case, the patient is a 16-year-old girl with a 1.5 cm × 1.2 cm OCD lesion of the medial femoral condyle. Technique Description: The patient was positioned supine with a tourniquet on the thigh. The lesion was identified on the medial femoral condyle and exposed. A guidepin was placed in the center of the lesion and a 15 mm reamer was used to ream to a depth of 6 to 7 mm. The wound was copiously irrigated. A corresponding 15 mm plug was harvested from the donor graft and prepared to match the morphology of the condyle. The 12 o’clock position was marked with a fresh marking pen to maintain orientation. The graft was lavaged with a pulsavac and bathed in autologous conditioned plasma. The recipient bed was prepared with 0.0045 K wire, and then the donor graft was placed in proper position and impacted with a tamp, flush with the surrounding cartilage. The tourniquet was deflated and the surgical site was closed in a layered fashion. Results: Studies of adult patients have demonstrated survival rates of greater than 80% for osteochondral allograft transplantation, with pain improvement of 74% to 85%, and return to competitive athletics of 88%. While there is a paucity of studies looking at osteochondral allograft transplantation in pediatric and adolescent populations, outcomes appear to be similar to that of the adult population. Discussion/Conclusion: Osteochondral allograft transplantation is a viable treatment option for pediatric and adolescent patients with symptomatic cartilage lesions. It allows for joint preservation and provides significant improvement of pain with high rates of return to athletics.

Anterior Cruciate Ligament Tears: The Impact of Increased Time From Injury to Surgery on Intra-articular Lesions.

Background:Previous research has shown that meniscal and articular cartilage lesions increase with time in the anterior cruciate ligament (ACL)–deficient knee.Purpose:To analyze the association between increased time from ACL injury to reconstruction and the presence of intra-articular lesions.Design:Cross-sectional study; Level of evidence, 3.Methods:A retrospective chart review was performed for patients who sustained an ACL injury and underwent reconstruction from January 1, 2009, to May 14, 2015. Factors analyzed included age, sex, and body mass index, as well as time from injury to surgery, the presence of meniscal tears, and the presence of cartilage lesions. The data were evaluated to quantify the association between time from ACL injury to reconstruction and presence of intra-articular lesions.Results:Overall, 405 patients were included in this study. Regarding time from injury, 27.3% patients were treated at <3 months, 23.6% at 3 to <6 months, 18% at 6 to <12 months, 13.6% at 12 to <24 months, 10.6% at 24 to <60 months, and 6.9% at ≥60 months. When compared with the group treated <3 months from injury, a significant increase in the rate of medial meniscal tears was seen in the groups treated at 6 to <12 months (odds ratio [OR], 2.2), 12 to <24 months (OR, 3.5), 24 to <60 months (OR, 7.0), and ≥60 months (OR, 6.3). A similar trend was seen with medial femoral condyle lesions in the groups treated at 6 to <12 months (OR, 2.5), 12 to <24 months (OR, 2.6), 24 to <60 months (OR, 2.6), and ≥60 months (OR, 6.9). The prevalence of lateral tibial plateau and lateral femoral condyle lesions also significantly increased with increased time between ACL injury and reconstruction, but this association was not seen until 24 to <60 months (ORs, 5.1 and 11.5, respectively).Conclusion:For patients undergoing ACL reconstruction, an interval >6 months between injury and surgery was associated with an increased prevalence of medial meniscal tears and medial compartment chondral lesions at the time of surgery. An interval >24 months between injury and surgery was associated with an increased prevalence of lateral compartment chondral lesions at the time of surgery.

Topographic Analysis of Lateral Versus Medial Femoral Condyle Donor Sites for Oblong Medial Femoral Condyle Lesions

To analyze the topographic matching of oblong osteochondral allografts to treat large oval medial femoral condyle (MFC) lesions using computer simulation models. The secondary objective was to determine whether lateral femoral condyle (LFC) grafts would have a similar surface matching when compared with MFC grafts in this setting. Human femoral hemicondyles (10 MFCs, 7 LFCs) underwent 3-dimensional computed tomography. Models were created from computed tomography images and exported into point-cloud models. Donor-recipient matches with large condylar width mismatch were excluded. The remaining specimen were divided into 3 donor-recipient groups with 2 defect sizes (17× 30 mm and 20× 30 mm): 20 MFC donor (MFCd)-MFC recipient (MFCr), 27 ipsilateral LFC donor (LFCd)-MFCr, and 26 contralateral LFCd-MFCr. Grafts were optimally virtually aligned with the MFCr defect. Mismatch of the articular cartilage and subchondral bone surfaces between the graft and the defect and articular step-off were calculated. MFCd grafts resulted in articular cartilage surface mismatch and peripheral step of less than 0.5 mm for both defect sizes. The subchondral bone surface mismatch was significantly greater than the articular cartilage surface mismatch (P < .01) in both defect sizes). Conversely, the ipsilateral and contralateral LFCd grafts resulted in significantly greater articular cartilage surface mismatch and step-off for both defect sizes when compared to MFCd grafts (P < .01). Oblong MFC allografts provide acceptable topographic matching for large oval MFC lesions when condylar width differences are minimized. However, concern exists in using oblong LFC allografts for MFC defects, as this can result in increased peripheral step-off and surface mismatch. These data reinforce the ability to use oblong MFC osteochondral allograft for treating oval cartilage lesions of the MFC when condylar width is considered. Although other studies have demonstrated LFCs can be used to treat circular defects on the MFC, this may not be true for oblong grafts.

Conservative Management and Serial Magnetic Resonance Imaging in an Athlete with Radiographically Unstable Juvenile Osteochondritis Dissecans of the Knee: Case Report

This report describes a case of radiographically unstable knee juvenile osteochondritis dissecans (JOCD) that healed without surgery. The authors utilize objective measurements of serial magnetic resonance imaging (MRI) to evaluate healing of the JOCD lesion and inform the decision to continue the course of conservative care or proceed to surgery. A 15-year-old soccer player presented with a 1-month history of worsening left knee pain. Magnetic resonance imaging showed an osteochondral lesion of the lateral femoral condyle with highly specific signs of instability including multiple cyst-like lesions (CLL) and large CLL diameter. An approach involving low-impact, low-intensity rehabilitative exercises and other modalities was implemented. Follow-up MRIs were performed at 3, 6, and 8 months to monitor changes and recalculate healing probability using a previously published nomogram. Clinical improvement was measured using outcome assessments. Follow-up MRIs showed a progressive reduction in size and number of CLLs and a resulting increase in healing probability from 20 to 70%. The patient successfully returned to play at just over 8 months after diagnosis. This case highlights that significant healing in knee JOCD is possible during a carefully monitored course of non-operative care, despite imaging signs of instability such as multiple and large CLL.

Scaffolds for Knee Chondral and Osteochondral Defects: Indications for Different Clinical Scenarios. A Consensus Statement.

To develop patient-focused consensus guidelines on the indications for the use of scaffolds to address chondral and osteochondral femoral condyle lesions. The RAND/UCLA Appropriateness Method (RAM) was used to develop patient-specific recommendations by combining the best available scientific evidence with the collective judgement of a panel of experts guided by a core panel and multidisciplinary discussers. A list of specific clinical scenarios was produced regarding adult patients with symptomatic lesions without instability, malalignment, or meniscal deficiency. Each scenario underwent discussion and a 2-round vote on a 9-point Likert-type scale (range 1-3 "inappropriate," 4-6 "uncertain," 7-9 "appropriate"). Scores were pooled to generate expert recommendations. Scaffold (chondral vs. osteochondral), patient characteristics (age and sport activity level), and lesion characteristics (etiology, size, and the presence of osteoarthritis [OA]) were considered to define 144 scenarios. The use of scaffold-based procedures was considered appropriate in all cases of chondral or osteochondral lesions when joints are not affected by OA, while OA joints presented more controversial results. The analysis of the evaluated factors showed a different weight in influencing treatment appropriateness: the presence of OA influenced 58.3% of the indications, while etiology, size, and age were discriminating factors in 54.2%, 29.2%, and 16.7% of recommendations, respectively. The consensus identified indications still requiring investigation, but also the convergence of the experts in several scenarios defined appropriate or inappropriate, which could support decision making in the daily clinical practice, guiding the use of scaffold-based procedures for the treatment of chondral and osteochondral knee defects.

Implantation of allogenic umbilical cord blood-derived mesenchymal stem cells improves knee osteoarthritis outcomes: Two-year follow-up.

IntroductionClinical outcomes after the implantation of allogenic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in osteoarthritic knees have been rarely reported. Our study aimed to investigate clinical outcomes of osteoarthritic patients who underwent hUCB-MSC implantation.MethodsIn this case series (level of evidence: 4), from January 2014 to December 2015, 128 patients with full-thickness cartilage lesions (International Cartilage Repair Society grade 4 and Kellgren–Lawrence grade ≤3) who underwent hUCB-MSC implantation were retrospectively evaluated with a minimum of 2-year follow-up. After removing the sclerotic subchondral bone with an arthroscopic burr, 4-mm-diameter holes were created at 2-mm intervals, and hyaluronic acid and hUCB-MSCs were subsequently mixed and implanted in the holes and other articular defect sites.Clinical outcomes were evaluated preoperatively, 1 year postoperatively, and 2 years postoperatively (minimum) using visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) scores. To assess clinical outcomes, patients were divided into two or three groups according to the lesion size, lesion location, number of lesions, body mass index, and age; statistical analyses were performed using these data.ResultsThe mean (±standard deviation) VAS, WOMAC, and IKDC scores at 1 and 2 years after surgery including hUCB-MSC implantation improved significantly compared to the preoperative scores (P < 0.001). There were significant differences in the lesion location (P < 0.05). Medial femoral condyle lesions resulted in worse outcomes compared with lateral femoral condyle and trochlea lesions. No adverse reactions or postoperative complications were noted.ConclusionsImplantation of hUCB-MSCs is effective for treating knee osteoarthritis based on a follow-up lasting a minimum of 2 years.