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Background: Satisfactory clinical results of meniscal allograft transplantation (MAT) have been reported in recent years. However, it remains unclear whether the clinical outcomes of MAT when combined with an osteotomy are inferior to those of isolated MAT. Purpose: To compare the survival rates and clinical outcomes of patients who received isolated medial MAT with those of patients undergoing medial MAT combined with high tibial osteotomy (HTO). Study Design: Cohort study; Level of evidence, 3. Methods: A total of 55 patients underwent arthroscopic medial MAT using the soft tissue technique and HTO (mean age, 41.3 ± 10.4 years; 9 female); after fuzzy case-control matching on demographics, 55 controls who underwent isolated medial MAT were also included. Survival analyses were performed using the Kaplan-Meier method with surgical failure, clinical failure (Lysholm score, <65), and reoperation as endpoints. Subjective clinical scores were collected preoperatively and at the final follow-up. Results: The mean follow-up time was 5.4 years, up to 8 years. All outcomes significantly improved at the last follow-up (P <.001). No differences were identified between MAT and MAT + HTO groups preoperatively and at the last follow-up (P >.05). At the final follow-up, 8 of 55 (14.5%) of the MAT + HTO patients and 9 of 55 (16.4%) of the MAT patients had a Lysholm score <65 (P =.885). Overall, 90% of the patients declared they would repeat the surgery regardless of the combined procedure. Surgical failure was identified in 6 of 110 (5.5%) patients: 5 of 55 (9.1%) in the MAT + HTO group and 1 of 55 (1.8%) in the MAT group (P =.093). Clinical failure was identified in 19 of 110 (17.3%) patients: 11 of 55 (20%) in the MAT + HTO group and 8 of 55 (14.5%) in the MAT group (P =.447). A significantly lower survivorship from surgical failure was identified in the MAT + HTO group (hazard ratio, 5.1; P =.049), while no differences in survivorship from reoperation and clinical failure were identified (P >.05). Conclusion: Patients undergoing medial MAT + HTO showed similar clinical results to patients undergoing isolated medial MAT at midterm follow-up, and thus a surgically addressed malalignment does not represent a contraindication for medial MAT. However, the need for a concomitant HTO is associated with a slightly higher failure rate over time. [ABSTRACT FROM AUTHOR]

Background: Meniscal allograft transplant (MAT) is an effective treatment for relieving symptoms and improving knee function in patients who experience symptomatic unicompartmental knee pain after a previous meniscectomy. However, the literature contains a paucity of studies assessing the survival rate and prognostic factors of soft tissue MAT. Purpose: To report the survivorship of a large, single-center cohort of consecutive patients treated with arthroscopic MAT using soft tissue technique and to investigate variables that could potentially influence failures and outcomes. Study design: Case series; Level of evidence, 4. Methods: Consecutive MAT procedures totaling 364 performed in a single institution between June 2004 and April 2019 were screened and assessed for eligibility. Subjective clinical scores (Lysholm score, Tegner activity scale, and visual analog score) were collected preoperatively and at 2, 5, 7, and 10 years of follow-up. Two survival analyses were performed using Kaplan-Meier curves, with surgical failure (defined as any graft revision) and clinical failure (defined as a Lysholm score <65 points) used as endpoints. Univariate analyses were performed using reoperations, surgical failure, clinical failure, and different demographic and surgical characteristics as endpoints. Results: A total of 324 consecutive patients were evaluated at a mean follow-up 5.7 ± 3.0 years. Of these, 189 (58%) underwent an associated surgical procedure. A total of 22 patients (6.8%) were considered to have experienced surgical failure, and no predictors of surgical failure were identified based on the relevant variables. When all patients were considered, a significant improvement in all of the patient-reported outcome measures was present between the preoperative assessment and the last follow-up (P <.001), with no significant decrease over time. Moreover, 70 (21.6%) patients were considered to have experienced clinical failure; the need for concurrent cartilage procedures (odds ratio, 0.16; P =.001) and anterior cruciate ligament (ACL) reconstruction (odds ratio, 0.40; P =.059) were predictors of failure. Finally, a lower survival rate was reported in female patients compared with male patients (49% vs 69%, respectively; P =.007) and in patients who required cartilage surgery (P =.014). In particular, patients who required cartilage surgery showed nearly half the survival rate compared with those with required no cartilage procedures at 10-year follow-up (36.4% vs 71%, respectively; P =.029). Conclusion: Female sex and the need to combine MAT with a cartilage procedure or ACL reconstruction could result in an increased rate of clinical failure at midterm follow-up. [ABSTRACT FROM AUTHOR]

Background: Collagen meniscal implant (CMI) is a biologic scaffold that can be used to replace meniscus host tissue after partial meniscectomy. The short-term results of this procedure have already been described; however, little is known about risk factors for failure. Purpose: To determine the factors that predict failure of meniscal scaffold implantation in a large series of patients treated at a single institution and to better define the indications for surgery. Study Design: Case-control study; Level of evidence, 3. Methods: The analysis included 186 consecutive patients with a minimum 5-year follow-up who underwent CMI scaffold implantation or combined procedures. Patients' characteristics and details of the surgery were obtained via chart review. Patients with a Lysholm score <65 were considered to have experienced clinical failure. Surgical failure was defined as partial or total scaffold removal. Results: The final analysis included 156 patients (84%) at a mean follow-up of 10.9 ± 4.3 years. The patients' mean age at surgery was 42.0 ± 11.1 years, and the survival rate was 87.8%. Subgroup analysis identified Outerbridge grade 3-4 (Hazard ratio [HR], 3.8; P =.004) and a lateral meniscal implant (HR, 3.2; P =.048) as risk factors for failure. The survival rate was 90.4% for medial implants and 77.4% for lateral implants. An Outerbridge grade 3-4 (HR, 2.8; P <.001) and time from meniscectomy to scaffold >10 years (HR, 2.8; P =.020) were predictive of surgical or clinical failure. Conclusion: CMI for partial meniscal deficiency provided good long-term results, with 87.8% of the implants still in situ at a mean 10.9 years of follow-up. Outerbridge grade 3-4, lateral meniscal implants, and longer time from the meniscectomy to implantation of the CMI were identified as risk factors for clinical and surgical failure. [ABSTRACT FROM AUTHOR]

Background: Platelet-rich plasma (PRP) is gaining large interest in clinical practice as a minimally invasive injective treatment for knee osteoarthritis (OA). Different preparation methods are available, and the presence of leukocytes, deemed detrimental in some preclinical studies, is one of the most debated aspects regarding PRP efficacy. Purpose: To compare the safety and effectiveness of leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) for the treatment of knee OA. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 192 patients with symptomatic knee OA (Kellgren-Lawrence grade 1-3) were randomly allocated to 3 weekly injections of LR-PRP or LP-PRP. LP-PRP was obtained with a filter for leukodepletion. LR-PRP and LP-PRP were divided into aliquots of 5 mL, with a mean platelet concentration of 1146.8 × 109/L and 1074.9 × 109/L and a mean leukocyte concentration of 7991.4 × 106/L and 0.1 × 106/L, respectively. Patients were evaluated at baseline and thereafter at 2, 6, and 12 months for the primary outcome, the International Knee Documentation Committee (IKDC) subjective score; and for secondary outcomes, the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, EuroQol–visual analog scale (EQ-VAS), and Tegner score. Results: No differences between groups were observed in terms of absolute values or improvement of the clinical scores across all follow-up intervals. The mean IKDC subjective score at baseline and 12 months improved from 45.6 to 60.7 in the LR-PRP group as compared with 46.8 to 62.9 in the LP-PRP group (P =.626). No severe adverse events were described in either group, although 15 mild adverse events (knee pain or swelling) were reported: 12.2% for LR-PRP and 4.7% for LP-PRP (P =.101). No statistically significant difference was also found between LR-PRP and LP-PRP in terms of failures (7.8% vs 3.5%, P =.331). Conclusion: This double-blind randomized trial showed that 3 intra-articular LR-PRP or LP-PRP injections produced similar clinical improvement in the 12 months of follow-up in patients with symptomatic knee OA. Both treatment groups reported a low number of adverse events, without intergroup differences. The presence of leukocytes did not significantly affect the clinical results of PRP injections. Registration: NCT02923700 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Background: Long-term patient-reported outcome measures (PROMs) and predictors of success or failure after anterior cruciate ligament (ACL) reconstruction are not fully understood, especially when combined with a lateral extra-articular reconstruction. Purpose: To assess the long-term PROMs, revision rate, and predictors of success or failure after ACL reconstructions using an over-the-top surgical technique with single-bundle hamstring tendon autografts and a lateral extra-articular reconstruction. Study Design: Case series; Level of evidence, 4. Methods: The study cohort consisted of 267 consecutive patients (mean age, 30.7 years) who underwent ACL reconstruction with an over-the-top surgical technique with single-bundle hamstring tendon autografts and a lateral extra-articular augmentation between November 2007 and May 2009. The number of subsequent ACL revisions and reoperations were recorded. Subjective clinical status was assessed with PROMs—specifically, the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and visual analog scale for pain—at a minimum follow-up of 10 years. Results: Overall, 3% of patients underwent ACL revision, with a 10-year survival rate of 96.3%. High sport activity (hazard ratio, 6.9; P =.285) and concomitant meniscal lesion (hazard ratio, 2.6; P =.0487) were predictors of ACL revision or new meniscectomy. The mean ± SD Lysholm score was 94.1 ± 10.8, while that for the visual analog scale for pain was 0.2 ± 0.9 at rest and 2.1 ± 2.6 during activity. KOOS subscale scores were as follows: 95.7 ± 8.1 for Pain, 92.5 ± 10.5 for Symptoms, 98.4 ± 7.4 for Activities of Daily Living, 90.7 ± 17.2 for Sport, and 91.2 ± 17.1 for Quality of Life; respectively, 88%, 99%, 81%, 89%, and 91% of patients achieved the Patient Acceptable Symptom State. Female sex and chondropathy with Outerbridge grade ≥2 were predictors of worse KOOS subscales. Overall, 82% of patients returned to sport, and 57% were still participating at the 10-year evaluation. Conclusion: ACL reconstruction with an over-the-top surgical technique with single-bundle hamstring autografts and a lateral extra-articular reconstruction provided satisfactory results in terms of function, symptoms, sports, and quality of life in 80% to 90% of patients after 10 years. Long-term survivorship was 96%. Sport participation declined from 82% postoperatively to 57% at long-term follow-up. A concomitant medial meniscal lesion was a predictor of higher risk of ACL failure or new meniscal lesion, while advanced chondropathy and female sex were predictors of higher pain, lower function, and poor quality of life scores. [ABSTRACT FROM AUTHOR]

Background: Matrix-assisted autologous chondrocyte transplantation (MACT) procedures have been developed to overcome some of the limits of first-generation autologous chondrocyte implantation. However, while good autologous chondrocyte implantation results have been documented over time, data are scarce on the long-term MACT results. Purpose: To evaluate long-term clinical results of a large cohort of patients treated with hyaluronic acid–based MACT for articular cartilage defects of the knee. Study Design: Case series; Level of evidence, 4. Methods: A long-term evaluation of 113 patients was performed (91 men, 22 women; mean ± SD age, 29.0 ± 10.6 years) for 115 knees affected by chondral and osteochondral lesions of the femoral condyles and trochlea. Of these, 61 knees had undergone previous surgery, while other procedures were combined during the same operation in 48 knees. These patients were prospectively evaluated before surgery and at 2, 5, and 10 years after surgery, as well as at a final mean follow-up of 15 years (range, 12-18 years), with various clinical scores: International Knee Documentation Committee (IKDC), EuroQol visual analog scale (EQ-VAS), and Tegner. Both surgical and clinical failures were documented. Results: The IKDC subjective score increased from the basal level of 39.9 ± 14.6 (mean ± SD) to 77.3 ± 20.5 (P <.0005) at 2 years; results remained stable up to the 15-year follow-up (76.9 ± 20.5). EQ-VAS and Tegner scores showed a statistically significant improvement up to 10 years, with a further significant improvement at the final follow-up. A failure rate of 15.0% was documented, which increased to 21.7% when clinical failures were also considered. A worse outcome was found for older age (P <.0005), female sex (P =.002), degenerative lesions (P <.0005), longer duration of symptoms (P =.005), and previous surgery (P <.0005). Conclusion: Arthroscopic MACT offered good and long-lasting results that were stable over time and resulted in a limited number of failures and reinterventions for up to 15 years of follow-up. Several factors were identified as having a prognostic value: a worse outcome could be expected in older patients, female patients, those affected by lesions with a degenerative cause, those having a longer duration of symptoms, and patients who underwent previous surgery. [ABSTRACT FROM AUTHOR]

Background: Meniscal allograft transplant (MAT) is considered an effective procedure for reducing pain and improving knee function. Nevertheless, the current knowledge regarding the results of MAT is limited to short- to mid-term follow-up studies, especially for arthroscopic techniques. Purpose: To evaluate the long-term clinical outcomes, reoperations, and failures with a minimum follow-up of 10 years after fresh-frozen MAT performed arthroscopically with soft tissue fixation. Study Design: Case series; Level of evidence, 4. Methods: A total of 46 patients (age, 36.6 ± 10.6 years; 36 male, 10 female) who underwent medial MAT (n = 27) or lateral MAT (n = 19) with a minimum 10-year follow-up were evaluated with the Lysholm score, Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale for pain, and Tegner score. Surgical failure was defined as the need for partial or total graft removal (meniscectomy or knee replacement), and clinical failure was defined as the need for partial or total graft removal in addition to a poor Lysholm score (<65 points) at final follow-up. Survival analysis was performed with Kaplan-Meier curve, and clinical scores were analyzed based on the Patient Acceptable Symptom State (PASS) for MAT. Results: 10-year survival and clinical data were available for 38 patients. Because 6 meniscectomies were required, the rate of survival free from surgical failure was 91% at 5 years and 86% at 10 years. Lower survival was reported in lateral MAT (73%) compared with medial MAT (96%). Because a further 4 patients had poor Lysholm scores, the rate of survival free from surgical and clinical failure was 87% at 5 years and 70% at 10 years. The average Lysholm score at final follow-up was 82 ± 20, and 60% to 82% of patients achieved PASS of the various KOOS subscales. The Tegner score and the KOOS Sport score significantly decreased from mid-term to long-term evaluation (P <.001 and P <.05, respectively). Other KOOS subscales and the Lysholm score remained stable at long-term evaluation. No significant differences were found between isolated MAT or combined MAT regarding subjective scores, surgical failures, or clinical failures. Conclusion: Up to 10 years after surgery, 86% of fresh-frozen MATs with soft tissue fixation were still in situ, and satisfactory clinical results were present for about 70% of patients. Decline of clinical outcomes from midterm to long term was noted only in sports-related scores. A higher number of overall reoperations was noted in female patients, whereas a higher risk of failure was present in the patients with lateral MAT. [ABSTRACT FROM AUTHOR]

Background: Arthroscopic debridement with graft preservation has been advocated as the treatment of choice for septic arthritis after anterior cruciate ligament (ACL) reconstruction, but no previous studies have investigated if hardware removal, while retaining the graft in situ, improves the success rate. Moreover, it is unclear whether the premature removal of fixation devices may affect graft integration and knee stability. Purpose/Hypothesis: The purpose was to assess the clinical and functional outcomes of patients with septic arthritis after ACL reconstruction who underwent arthroscopic debridement, while retaining the graft in situ but removing fixation devices, and to determine if premature hardware removal affects graft integrity and function. The hypothesis was that arthroscopic debridement with hardware removal would be effective in eradicating infections while not compromising graft integration and function. Study Design: Case series; Level of evidence, 4. Methods: From a cohort of 2384 cases of arthroscopic ACL reconstruction, 24 patients with postoperative septic arthritis were included for the analysis; 18 patients were available for a clinical evaluation using the International Knee Documentation Committee (IKDC) form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, and Tegner score at a minimum 12-month follow-up. Knee laxity was assessed clinically with standardized manual laxity tests and instrumentally using an arthrometer and a triaxial accelerometer. Additionally, 3-T magnetic resonance imaging (MRI) at final follow-up was performed, focusing on the graft signal, the cartilage status, and the occurrence of arthrofibrosis. Results: Eradication of the infection was achieved in all cases, and only 1 graft removal was performed because of insufficient tension. Among the remaining 23 patients, a single arthroscopic debridement procedure with hardware removal while preserving the graft was effective in 21 cases (91%) at a mean of 30 ± 37 days from ACL reconstruction to debridement. At last follow-up, 2 patients required a further ACL revision procedure. The mean IKDC, WOMAC, Lysholm, and Tegner scores of the patients available for the clinical evaluation were 75 ± 19, 90 ± 8, 79 ± 21, and 6 ± 2, respectively. No abnormal laxity was reported on manual testing, and arthrometric and accelerometer tests also demonstrated good knee stability (mean KT-1000 arthrometer side-to-side difference was 1.6 ± 1.2 mm at manual maximum force). On MRI, a good graft signal was found in 50% of cases, while concomitant signs of arthrofibrosis were detected in 81% of patients. Severe cartilage defects (International Cartilage Repair Society grade ≥3) were reported in 63% of cases. Conclusion: Arthroscopic debridement with hardware removal was effective in the eradication of infections after ACL reconstruction with extra-articular fixation while preserving graft integrity without compromising knee stability. Patients and surgeons should be aware of complications that might affect the outcome, particularly arthrofibrosis and chondrolysis. [ABSTRACT FROM AUTHOR]

Background: A biodegradable polyurethane scaffold was developed to treat patients with the challenging clinical condition of painful partial meniscal defects. Hypothesis: The use of an acellular polyurethane scaffold in patients with symptomatic partial meniscal defects would result in both midterm pain relief and improved function. Study Design: Case series; Level of evidence, 4. Methods: A total of 155 patients with symptomatic partial meniscal defects (101 medial and 54 lateral) were implanted with a polyurethane scaffold in a prospective, single-arm, multicentric study with a minimum 5-year follow-up. Clinical outcomes were measured with the visual analog scale for pain, International Knee Documentation Committee subjective knee evaluation form, Lysholm knee scale, and Knee injury and Osteoarthritis Outcome Score at baseline and at 2- and 5-year follow-ups. Magnetic resonance imaging (MRI) was used to evaluate the knee joint, meniscal implant, and meniscal extrusion. Kaplan-Meier survival analysis was also performed. Removal of the scaffold, conversion to a meniscal transplant, and unicompartmental/total knee arthroplasty were used as endpoints. Results: Eighteen patients were lost to follow-up (11.6%). The patients who were included in this study showed significant clinical improvement after surgery as indicated by the different outcome measures (P =.01). However, the clinical improvement tended to stabilize between 2 and 5 years of follow-up. MRI scans of the scaffolds in 56 patients showed a smaller-sized implant in the majority of the cases when compared with the native meniscus with an irregular surface at the 5-year follow-up. During the follow-up period, 87.6% of the implants survived in this study. At 5 years of follow-up, 87.9% of the medial scaffolds were still functioning versus 86.9% of the lateral scaffolds. In total, 23 treatments had failed: 10 removed scaffolds because of breakage, 7 conversions to meniscal allograft transplantation, 4 conversions to unicompartmental knee arthroplasty, and 2 conversions to total knee arthroplasty. Conclusion: The polyurethane meniscal implant was able to improve knee joint function and reduce pain in patients with segmental meniscal deficiency over 5 years after implantation. The MRI appearance of this scaffold was different from the original meniscal tissue at the midterm follow-up. The treatment survival rates of 87.9% of the medial scaffolds and 86.9% of the lateral scaffolds in the present study compared favorably with those published concerning meniscal allograft transplantation after total meniscectomy. [ABSTRACT FROM AUTHOR]

Background: Failure of anterior cruciate ligament (ACL) reconstruction or an injury to the ACL in the contralateral knee represents a devastating event for patients, especially those young and physically active. However, controversies are still present regarding long-term failure rates and risk factors. Purpose: To assess the long-term rate of ipsilateral graft failure and contralateral ACL injuries after ACL reconstruction performed at a single center using the same surgical technique with a hamstring autograft and to investigate the effect of sex, age, and preinjury activity level as predictors of second ACL injuries. Study Design: Case series; Level of evidence, 4. Methods: The study cohort consisted of 244 consecutive patients (mean age, 30.7 years) who underwent ACL reconstruction with a single bundle plus lateral plasty technique using the hamstring tendon between November 2007 and May 2009. The number of subsequent ACL injuries (ipsilateral ACL revision or contralateral ACL reconstruction) was determined at a minimum follow-up of 10 years. Survivorship of either knee and subgroup analysis included sex, age, preoperative Tegner activity level, timing of ACL reconstruction, body mass index, and smoking status. Results: Ipsilateral ACL revision was performed in 8 (3.4%) patients and contralateral ACL reconstruction in 19 (7.8%) patients. Only 1 patient had both ipsilateral and contralateral injuries. No predictors were found for ipsilateral ACL revision, while age <18 years and preoperative Tegner level ≥7 had a higher risk of contralateral ACL reconstruction. The highest rate of a second ACL reconstruction procedure was in young (<18 years) and active (Tegner ≥7) patients, in whom the 10-year survival of either knee was 61.1%. Six years after primary ACL reconstruction, the rate of contralateral ACL reconstruction was significantly higher than that of ipsilateral ACL revision (hazard ratio, 2.4-3.6). Conclusion: In the long term, a second injury to either the ipsilateral or the contralateral knee in young and active populations could reach 40%, with a more than double-fold risk of contralateral ACL reconstruction compared with ipsilateral ACL revision. [ABSTRACT FROM AUTHOR]

Background: There are few published studies with very long-term follow-up of combined intra- and extra-articular anterior cruciate ligament (ACL) reconstruction. Purpose: To analyze clinical and radiographic outcomes of over-the-top ACL reconstruction plus extra-articular lateral tenodesis with autologous hamstrings at minimum 20-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: Of 60 originally eligible patients who underwent over-the-top ACL reconstruction with double-stranded hamstring tendon (leaving intact graft tibial insertions) and extra-articular lateral plasty (performed with the remnant part of tendons), 52 were prospectively evaluated at a minimum 20-year follow-up (mean follow-up, 24 years; 41 men, 11 women; mean age at time of surgery, 25.5 ± 7.6 years). Twenty-nine patients were available for prospective evaluations: clinical (Lysholm, Tegner, and objective International Knee Documentation Committee [IKDC]), instrumented (KT-2000), and radiographic (standard, long-standing, and Merchant views). Subjective KOOS (Knee injury and Osteoarthritis Outcome Score) and objective inertial sensor pivot-shift analysis (KiRA) were carried out at final follow-up. Twenty-three patients were investigated by phone interview for subjective Tegner score and documented complications, rerupture, or revision surgery. Results: At final follow-up, mean Lysholm score was 85.7 ± 14.6; median Tegner score, 4 (range, 3-5); sport activity resumption, 86.2%; and objective IKDC score, good or excellent in 86% of patients (31%, A; 55%, B). Only 3 of 26 patients (12%) had >5-mm manual maximum KT-2000 side-to-side difference. KiRA system documented positive pivot-shift (>0.9-m/s2 tibial acceleration side-to-side difference) in these 3 of 26 patients (12%). Statistically significant changes were as follows: decrease in Tegner score from 7 (range, 6-8) at 5-year follow-up to 4 (range, 3-5) at 10 years (P < .0001) and decrease in Lysholm score from 96.1 ± 7.3 at 10-year follow-up to 85.7 ± 14.6 at 20 years (P = .0003). Radiographic evaluation demonstrated significant difference of medial joint space between injured and healthy knees in patients with concomitant medial meniscectomy (n = 8, 3.2 ± 0.6 vs 5.0 ± 1.8 mm, P = .0114). No significant differences were reported regarding lateral or patellofemoral joint space. One patient (2%) experienced rerupture, with 3 of 52 (5.8%) having a contralateral ACL injury (excluded from KT-2000 and radiographic evaluations). Overall, 4 of 29 clinical failures (objective IKDC, KT-2000) and 1 rerupture among 52 patients were registered at final follow-up. Conclusion: Studied surgical technique demonstrated good results in laxity control at 20-year minimum follow-up. The lateral extra-articular plasty associated with ACL reconstruction did not generate lateral knee or patellofemoral osteoarthritis. The factor increasing osteoarthritis was meniscectomy. [ABSTRACT FROM AUTHOR]

Background: The treatment of symptomatic cartilage defects of the patella is particularly challenging, and no gold standard is currently available. Purpose: To evaluate the clinical results of a biphasic cell-free collagen-hydroxyapatite scaffold and to evaluate osteochondral tissue regeneration with magnetic resonance imaging (MRI). Study Design: Case series; Level of evidence, 4. Methods: Thirty-four patients (18 men and 16 women; mean ± SD: age, 30.0 ± 10 years) were treated by scaffold implantation for knee chondral or osteochondral lesions of the patella (area, 2.1 ± 1 cm2). The clinical evaluation was performed prospectively at 12 and 24 months via the IKDC (International Knee Documentation Committee; objective and subjective) and Tegner scores. MRI evaluation was performed at both follow-ups in 18 lesions through the MOCART score (magnetic resonance observation of cartilage repair tissue) and specific subchondral bone parameters. Results: A statistically significant improvement in all the scores was observed at 12- and 24-month follow-up as compared with the basal evaluation. The IKDC subjective score improved from 39.5 ± 14.5 to 61.9 ± 14.5 at 12 months (P > .0005) with a further increase to 67.6 ± 17.4 at 24 months of follow-up (12-24 months, P = .020). The MRI evaluation showed a stable value of the MOCART score between 12 and 24 months, with a complete filling of the cartilage in 87.0% of the lesions, complete integration of the graft in 95.7%, and intact repair tissue surface in 69.6% at final follow-up. The presence of osteophytes or more extensive bony overgrowth was documented in 47.8% of the patients of this series, but no correlation was found between MRI findings and clinical outcome. Conclusion: The implantation of a cell-free collagen-hydroxyapatite osteochondral scaffold provided a clinical improvement at short-term follow-up for the treatment of patellar cartilage defects. Women had lower outcomes, and the need for realignment procedures led to a slower recovery. MRI evaluation showed some abnormal findings with the presence of bone overgrowth, but no correlation has been found with the clinical outcome. [ABSTRACT FROM AUTHOR]