Patellofemoral Chondral Defects Research Articles

Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) Scores > 55 at 6 Months Postoperative Predict Ability to Achieve Patient Acceptable Symptomatic State at Minimum 1 Year Postoperative Following Autologous Chondrocyte Implantation for Grade IV Chondral Defects About the Patellofemoral Joint.

The primary aim is to evaluate the relationship between MOCART scores and patient satisfaction, as evaluated by achievement of (1) the Patient Acceptable Symptomatic State (PASS) and (2) the minimal clinically important difference (MCID) for Knee Injury and Osteoarthritis Score Quality of Life (KOOS QoL), for patients undergoing autologous chondrocyte implantation (ACI) for focal Grade IV patellofemoral chondral defects. The secondary aim is to determine the threshold MOCART score which predicts the ability to meet the PASS and the MCID for KOOS QoL. Patients undergoing ACI for grade IV patellofemoral chondral defects by a single surgeon from 2017 to 2020 were identified by search of the EMR. To determine PASS status, patients were asked, "Do you consider your current level of symptoms to be acceptable?" KOOS QoL scores were also collected. Patients with 6-month postoperative knee MRI, PASS scores, and minimum 2-year follow-up data were included. Paired t tests and Wilcoxon Rank-Sum tests were used to evaluate the relationship between MOCART scores and (1) PASS achievement and (2) achievement of the MCID for KOOS QoL (12.8). Thirty-four patients were included, with a median age of 35.1 years [IQR: 24.6, 37.1], and BMI of 24.0 kg/m2 [IQR: 21.5, 28.1]. The median time to postoperative MRI was 6.7 months [IQR: 5.8, 7.9], and average follow-up time was 3.7 ± 1.2 years. Twenty-five patients (74%) achieved PASS, and 18 patients (out of 27 who had postop KOOS QoL Scores, 67%) achieved the MCID for KOOS QoL. Patients who achieved PASS had higher average MOCART scores (61.8 ± 16.0) than those who did not achieve PASS (45.0 ± 12.8, p=0.011), whereas patients who achieved the MCID for KOOS QoL did not have higher MOCART scores than those who did not achieve the MCID (61.9 ± 18.3 versus 53.3 ± 17.1, P = 0.25). There was no relationship between age, sex, lesion size, and lesion location and ability to achieve PASS or MCID for KOOS QoL (p>0.05). A threshold MOCART value of 55 was associated with the highest AUC on ROC analysis for likelihood of achieving PASS (0.778) and MCID for KOOS QoL (0.667). Higher MOCART scores are associated with an increased likelihood of achieving PASS following patellofemoral ACI. Moreover, MOCART scores > 55 predict the ability to achieve PASS and the MCID for KOOS QoL following patellofemoral ACI. IV.

Positive outcomes following Autologous Matrix-Induced Chondrogenesis (AMIC) in the treatment of retropatellar chondral lesions: a retrospective analysis of a patient registry

BackgroundThe patellofemoral joint is a challenging environment for treating chondral defects. Among the surgical options for the treatment of chondral defects, the single-stage Autologous Matrix-Induced Chondrogenesis (AMIC) procedure uses a porcine collagen I/III membrane to enhance bone-marrow stimulation. However, longer term outcomes data are rare for this specific indication. In order to provide real-world information, an ongoing registry has been established to record patient data and outcomes when AMIC is used to treat chondral and osteochondral lesions.MethodsPatient data were retrieved from an ongoing, prospective, multisite registry of patients who had undergone AMIC treatment of chondral defects. We identified 64 patients who had undergone AMIC for patellofemoral chondral defects and for whom pre-operative and at least 1 post-operative score were available were included in this retrospective data analysis. Outcomes were assessed via the KOOS, VAS pain, and the Lysholm scores. Outcomes at the post-operative time-points were analysed using a factorial ANOVA with post-hoc testing while linear regression was used to assess associations between the change in the Lysholm score and lesion size.ResultsThere was a significant improvement in Lysholm, VAS pain, and KOOS scores from pre-operative to the 1st year post-operative (p < 0.001), and this was maintained during the follow-up.ConclusionsThe forces exerted on the patellofemoral joint make this a challenging scenario for chondral repair. Our data demonstrates that the AMIC procedure with a collagen I/III membrane is an effective treatment for retropatellar cartilage lesions, and provides reliable results, with decreased pain and improved function. Importantly, these improvements were maintained through the follow-up period.

Foot Strike Run Retraining forPatients With Patellofemoral Chondral Defects: A Case Series.

Military service members (SMs) demonstrate high rates of patellofemoral chondral defects (PFCDs) that are difficult to diagnosis and, if untreated, result in a cascade of events eventually leading to osteoarthritis. Running is an essential occupational task for SMs; however, there is little evidence regarding techniques to maintain running ability in individuals with cartilage defects. The purpose of this case series was to assess the clinical application of foot strike run retraining in patients with PFCDs. This case series included two active duty U.S. Marine Corps SMs who presented to outpatient physical therapy with PFCD, diagnosed via MRI. Both patients attended eight foot strike run retraining sessions. Running mechanics and patient-reported outcomes were recorded pre-training, post-training, and at a 1-month follow-up visit. Both patients successfully converted their strike pattern from a rearfoot to a non-rearfoot strike pattern with training and retained this strategy at 1-month follow-up. Post-intervention, both patients demonstrated increased running tolerance, and improvements in Numeric Pain Rating Scale and Lower Extremity Functional Scale scores. Biomechanical analysis showed that both patients demonstrated a 63% to 70% reduction in average and peak vertical ground reaction force loading rates post-treatment. Modification of foot strike pattern from rear to non-rearfoot strike during running for individuals with PFCD can reduce the magnitude of impact loading, which potentially limits disease progression. These findings suggest that foot strike run retraining may be a feasible strategy to reduce pain and improve function in SMs with PFCD who are required to run for occupational responsibilities.

Osteochondral Allograft Transplant for Combined Medial and Lateral Patellar Cartilage Lesions: The Osteochondral Wide Lesion (OWL) Technique

Symptomatic articular cartilage injuries are often seen in young active patients and athletes. Magnetic resonance imaging screening examinations have frequently identified such lesions in athletic patients. Patellofemoral chondral defects were previously identified as the most common knee cartilage lesion in high-level athletes. Chondral defects measuring 2 cm2 or greater and complex cartilage defects involving bone loss are ideally replaced with fresh osteochondral allograft. We describe a technique indicated for patients with symptomatic and recurrent anterior knee pain associated with osteochondral patellar defects including the lateral and medial patellar facets. Patients who have undergone previous interventions, including membrane techniques, microfracture, or autologous chondral transplantation, without clinical benefit are also eligible to undergo osteochondral allograft transplantation for combined medial and lateral patellar cartilage lesions, that is, the osteochondral wide lesion (OWL) technique.

PATELLOFEMORAL JOINT CARTILAGE RESTORATION WITH PARTICULATED JUVENILE ALLOGRAFT IN PATIENTS UNDER 21 YEARS OLD: POSTOPERATIVE MRI ANALYSIS AND RETURN TO SPORT RATES

Background:Patellofemoral joint cartilage defects are difficult to treat due to their unique thickness and topography. Numerous cartilage restoration techniques are available to surgeons treating articular cartilage defects. However, patellofemoral joint restoration historically produces worse outcomes than tibiofemoral joint restoration. One cell-based option is particulated juvenile allograft cartilage (PJAC), though literature regarding the efficacy of this treatment is sparse, especially in patients under the age of 21 years.Hypothesis/ Purpose:The aim of this study is to investigate postoperative outcomes of PJAC for patellofemoral chondral defects using MRI and return to sport rates in this active, high-demand patient population.Methods:Patients at an urban tertiary care musculoskeletal institution who underwent PJAC for patellofemoral joint cartilage restoration were identified through records review. Patients 21 years old or younger with minimum clinical follow-up of 1 year and postoperative MRI at a minimum of 6 months after surgery were included. Cartilage restoration was assessed by MRI using the International Cartilage Repair Society’s standardized system. Sport activity was collected from medical records.Results:Thirty-six knees in 34 patients with a mean age of 16.1 ± 3.1 years old (range 10—21 years old) were analyzed. Mean follow-up was 32.1 months. Defects were located on the patella in 25 knees, and trochlea in 11 knees (Figure 1). There were no bipolar lesions in the cohort. Mean defect size was 2.47 cm2. Twenty-four knees (66.7%) were graded either ‘normal’ or ‘nearly normal’, and 28 knees (77.8%) had greater than 50% of the defect filled on follow-up imaging. Return to sport rates among patients who participated in a sport preoperatively was 100%.Conclusion:Restoration of patellofemoral chondral defects in young patients with particulated juvenile allograft can be performed with satisfactory short-term efficacy, excellent postoperative MRI appearance, and very high rates of return to sport.Tables/Figures:Figure 1.PJAC Surgical Cases. (A) – (C) A patient with recurrent patellofemoral instability (A) Arthroscopic image demonstrating full-thickness defect at inferior portion of patella. (B) Defect bed prepared with vertical walls. (C) PJAC implanted, set and margins sealed with fibrin glue to achieve congruity with adjacent cartilage. (D) — (F) A patient with JOCD (D) Large crater defect of lateral trochlea, friable and easily removed with probe. (E) Approximately 2 x 1.5 cm lesion curetted down to layer of subchondral bone. (F) Initial PJAC placement over bed of fibrin glue. (G) — (I) A patient with recurrent patellofemoral instability. (G) Pre-operative axial T2 MRI demonstrating displaced patella chondral fragment (yellow arrow) and resulting defect (H) Post-operative axial T2 MRI at 1 year demonstrating 75% fill (white arrow). (I) Arthroscopic image of PJAC graft at 18-months post-operative during removal of hardware surgery, demonstrating excellent fill, and some small fraying cartilage, which was gently debrided.

Comparison of Clinical Outcomes in the Treatment of Patellofemoral Chondral Defects: Autologous Chondrocyte Implantation versus Fresh Osteochondral Allografts

Objectives: The complex environment and the extreme stresses of the patellofemoral joint make chondral defects a challenge to treat. Autologous chondrocyte implantation (ACI) and osteochondral allograft transplantation (OCA) have been reported as case series in the patellofemoral joint with mixed results. This study compared the clinical outcomes for ACI and OCA treatments for patellofemoral chondral defects at our institution. Methods: We reviewed all consecutive patients undergoing ACI and OCA at a single institution for the treatment of isolated patellofemoral cartilage defects. Treatment type was based on surgeon preference. Medical records were examined for patient demographic, lesion specific data, complications, re-operations and failures (graft delamination requiring surgery, revision cartilage repair or conversion to arthroplasty). Clinical outcomes included International Knee Documentation Committee (IKDC) and Short Form 12 health survey (SF-12) scores. Mean follow up was 5.2 years (range, 3.1-7.5 years). Results: There were 30 patients: 19 in the ACI group and 11 in the OCA group with a mean age of 33 (15-48) and 25.5 (16-55) respectively (p=0.12). Etiology in the ACI group was 63%(n=12) patellar instability, 21%(n=4) post-traumatic osteoarthritis, 10%(n=2) primary osteoarthritis and 5%(n=1) osteochondritis dissecans, whereas it was more evenly distributed in the OCA group (27%, 27%, 19% and 27% respectively). Lesions in the ACI group were either Fulkerson type III (84% (n=16), medial patellar facet) or type IV (16%(n=3), pan-patellar). In the OCA group, lesions varied between type 1 (9%(n=1)), type II (27%(n=3)), type III (9%(n=1)) and type IV (54%(n=6)). The mean lesion size was similar between the two groups (OCA 3.1 cm2 ±1.1 vs. ACI 3.4 cm2 ±2.4, p=0.7) with more bipolar lesions in the OCA group (45%(n=5) vs.11%(n=2), p=0.038). Failures (requiring revision or replacement surgery), were significantly more common in OCA at 36% (n=4) compared to 5.3% (n=1) in ACI patients (p=0.04), one of which was bipolar in the former group. Re-operation was performed in 27%(n=3) OCA patients (each for adhesiolysis) and in 21%(n=4) ACI patients (2 manipulation under anesthesia, 1 adhesiolysis and 1 graft debridement for overgrowth) (p=0.3). There were no significant differences between the OCA and ACI groups in IKDC (60.7 vs. 74, p=0.08) and SF-12 scores (43.5 vs 43.7, p=0.43). Conclusion: Compared to ACI, OCA had significantly more failures for patellofemoral chondral defects at short to mid-term follow-up. This may relate to differences in the etiology and lesion locations between the two groups. Despite these findings, both groups had similar complication rates and functional outcome scores.

Autologous Chondrocyte Implantation and Tibial Tubercle Osteotomy for Patellofemoral Chondral Defects: Improved Pain Relief and Occupational Outcomes Among US Army Servicemembers

Background: The occupational and functional results of patellofemoral autologous chondrocyte implantation (ACI) are underreported. This investigation sought to establish clinical outcomes and rates for return to work in a predominantly high-demand military cohort undergoing this procedure. Purpose: To determine the return-to-work, pain relief, and perioperative complication rates in a high-demand athletic cohort undergoing patellofemoral ACI. Study Design: Case series; Level of evidence, 4. Methods: All military servicemembers from 2 military medical centers undergoing ACI for high-grade patellofemoral chondral defects between 2006 and 2014 were identified, and data were abstracted from their medical records and clinical databases. Demographic and surgical variables were obtained for patients with at least 2 years of postoperative follow-up, and perioperative complications, rates of return to work, and survivorship from revision were quantified. Results: Seventy-two patients (72%) had >2-year follow-up and had patellofemoral ACI for high-grade chondral defects, with 66 knees (91%) undergoing a concomitant offloading tibial tubercle osteotomy. Mean follow-up was 4.3 years (range, 2.0-9.9 years). The mean ± SD age was 34.4 ± 6.1 years; 86% were male; and 57% were involved in military occupational specialties of heavy or very heavy demand. Second-generation patellofemoral ACI with a type I/III collagen membrane was used for 85% of knees. Most defects were isolated to the patella (n = 40, 55%). The mean total defect surface area was 4.5 ± 2.9 cm2 (range, 2.7-13.5 cm2). Fifty-six servicemembers (78%) returned to their occupational specialties. Three patients (4.1%) were classified as having surgical failures, requiring subsequent knee arthroplasty (n = 2) or a revision chondral procedure (n = 1). Mean visual analog scores improved significantly from 6.5 ± 1.5 to 3.2 ± 2.1 (P < .0001). Multivariate analysis identified use of a periosteal patch as the only significant independent predictor for surgical (P = .013) and overall (P = .033) failures. Age <30 years (P = .019), female sex (P = .019), and regular tobacco use (P = .011) were independent predictors of overall failure. Conclusion: For patellofemoral chondral defects without a failed primary procedure, second-generation ACI successfully returned to work 78% of patients of moderate to very heavy occupational demand with significantly decreased patient-reported knee pain. Risk factors after ACI for patellofemoral articular lesions for overall failure were age <30 years, female sex, and tobacco use, while surgical and overall failures were associated with periosteal patch use.

Cartilage Restoration: Microfracture and Osteochondral Autograft Transplantation.

The treatment of patellofemoral cartilage defects presents several distinct challenges when compared with cartilage restoration techniques used for other compartments of the knee due to the unique anatomy and distribution of forces. The etiologies of patellofemoral articular cartilage lesions include acute traumatic instability injuries, such as dislocation and subluxation, osteochondritis dissecans, and chronic degenerative changes. Regardless of the etiology, untreated patellofemoral cartilage lesions can contribute to activity-limiting anterior knee pain. The goal of patellofemoral cartilage restoration procedures is to impart symptomatic relief and improve quality of life by repairing the articular cartilage surface and any comorbid malalignment or maltracking.Microfracture and osteochondral autograft transplantation (OAT) are two cartilage restoration procedures to consider when treating full-thickness patellofemoral chondral defects. Considered by some experts to be the gold standard therapy, microfracture is one of the most common procedures used for cartilage restoration. The technique involves the perforation of the subchondral bone plate for the release of marrow elements, filling the defect with a fibrocartilage clot repair. Though less commonly used, OAT allows defect replacement with native hyaline cartilage via autologous transplantation from a non-weight bearing area. The purpose of this article is to discuss the indication, technical considerations, and outcomes of microfracture and OAT when used for treating chondral lesions of the patellofemoral joint.

Use of Fresh Osteochondral Allografts in the Patellofemoral Joint.

Fresh osteochondral allograft (OCA) transplantation has become a mainstay for the treatment of osteochondral defects in the tibiofemoral joint. With excellent outcomes and high survival times, this technology has recently become more interesting for use in the patellofemoral (PF) joint. This review article will point out the historical difficulties that the use of fresh OCA poses. With newer surgical approaches and a better understanding of the mechanical requirements of the PF joint, the use of OCA transplantation has shown increasingly better results. Illustrating the technique for the preparation and implantation of single plug allografts and bulk allografts to the trochlea and patella as well as the analysis of the available literature, we point out the current state of the art as well as potentially achievable long-term results. Finally, we will point out emerging technology seeking to further develop the use of allograft technology in patellofemoral chondral defects.

Second Generation Autologous Chondrocyte Implantation in the Patella: Improved Pain Relief and Functional Outcomes among U.S. Army Servicemembers

Objectives:To evaluate the functional outcomes of autologous chondrocyte implantation (ACI) for high-grade patellofemoral chondral defects in a predominately young, high-demand military demographic.Methods:We conducted a retrospective review of all United States military and Tricare beneficiaries undergoing ACI for Outerbridge grade III or IV patellofemoral chondral defects at a two high-volume military medical centers between 2007 and 2014. Second generation surgical technique was performed using autologous cultured chondrocytes (Vericel, Inc; Boston, MA) secured with a type I/III collagen bilayer membrane. Inclusion criteria required minimum two-year surveillance, although patients with knee-related medical discharge were also included to limit non-responder bias. Exclusion criteria were applied to individuals with predominately condylar involvement, periosteal patch coverage, and/or procedure miscoding Demographic information, surgical characteristics, and clinical outcomes were extracted from the electronic medical record. Averages were calculated with standard deviations (SD). Univariate analysis was used to determine significant independent predictors of surgical failure, which was defined as revision chondral procedure or conversion to arthroplasty. Relative risk was quantified with use of odds ratios (OR) with 95% confidence intervals (95% CI).Results:A total 57 patients with 58 knees were identified at average 2.13 year follow-up within the military health care system. The median age was 33.8 years (range, 20.3 to 49.9). Males comprised 77% of patients (n=44), and 93% (n=53) were active duty military status. Mean patient body mass index (BMI) was 30.3 kg/m2, tobacco use was documented in at least 19.3% (n=11), and only one patient had failed prior marrow stimulation procedure. The average lesion size for ACI was 502 mm2 (SD 318; range, 121-1600 mm2) and most defects were based on patella (91.3%). The average tibial tubercle-trochlear groove (TT-TG) distance was 13.9 mm (SD 3.5), and nearly all knees underwent concomitant anteromedializing or offloading tibial tubercle osteotomy (n=56; 97%). Additionally, only three patients required proximal realignment procedure. Only 1 patient (1.7%) required revision chondral procedure, and there were no cases of graft site hypertrophy or conversion to knee arthroplasty. With a “high” or “severe” average patient-reported pain level (86%), the average postoperative visual analog scale (VAS) was 2.3 (SD 2.2; median, 2) at final follow-up. At an average of 1.9 years postoperatively, 14 patients (24.6%) underwent medical discharge due to reported persistent, rate-limiting knee pain, although the average patient-reported VAS was 3 (SD 2.3; range, 0 to 6). No demographic or surgical variables were significantly associated with subsequent adverse clinical outcome (p>0.05).Conclusion:For patellofemoral chondral defects without failed primary procedure, second generation ACI can successful decrease patient-reported anterior knee pain among highly-active and athletic subsets. Approximately 75% of patients resumed modified military duty or preoperative level of function at short-term follow-up, and only 2% underwent revision. Knee related medical discharge occurred in nearly a quarter of patients, but did not preclude significant pain relief or return to lower demand activities.

Treatment of “Patellofemoral” Cartilage Lesions With Matrix-Assisted Autologous Chondrocyte Transplantation

Background: Matrix-assisted autologous chondrocyte transplantation (MACT) has been shown to offer good outcomes at midterm follow-up, but results are heterogeneous among different patients and lesion types. Being part of the same joint, both patellar and trochlear cartilage lesions are commonly considered to be affected by the same treatment issues, and therefore, it is common practice to report results obtained treating these lesions together. Purpose: To determine, in a large cohort of patients prospectively followed at midterm follow-up for patellofemoral chondral defects, if patellar and trochlear defects actually represent different clinical conditions with different healing potentials after cartilage treatment. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 49 consecutive patients with full-thickness patellofemoral chondral lesions of the knee were treated with MACT at the authors’ institute and followed prospectively for a minimum follow-up of 5 years. Among these 49 patients, 28 were affected by patellar lesions, 17 were affected by trochlear lesions, and 4 had both patellar and trochlear defects. The clinical outcome was analyzed with International Knee Documentation Committee (IKDC) subjective, EuroQol visual analogue scale (EQ-VAS), Kujala, and Tegner scores. Results: A statistically significant improvement in all scores was observed after treatment. Patellar lesions required more realignment procedures and were more common in women. The comparative analysis showed better results for trochlear lesions compared with patellar lesions at all follow-ups, with mean IKDC scores at 5-year follow-up of 89.6 ± 12.7 and 69.7 ± 17.6, respectively (P < .0005). Better results were also shown for the mean Kujala score (92.4 ± 14.7 vs 81.5 ± 12.7, respectively; P = .012) and mean EQ-VAS score (90.0 ± 10.8 vs 81.9 ± 11.7, respectively; P = .027). Finally, the sport activity level evaluated with the Tegner score confirmed the same trend; even though neither patellar nor trochlear lesion groups reached the preinjury level, both improved after treatment, with a significantly higher improvement in the trochlear lesion group (5.9 ± 1.8 vs 3.9 ± 1.7, respectively; P < .0005). Conclusion: Patient characteristics differ between patellar and trochlear cartilage defects, and moreover, the results obtained are significantly different, with a markedly good outcome in cases with trochlear lesions and less satisfactory results for patients affected by cartilage lesions of the patella. Thus, patellar and trochlear defects should be considered separately when evaluating the outcome of cartilage treatments in this anatomic region.

Patello-femoral cartilage damage: patients with grade 4 chondral defects of the patella have increased disability

Patello-femoral cartilage damage: patients with grade 4 chondral defects of the patella have increased disability

Improved Outcomes With Combined Autologous Chondrocyte Implantation and Patellofemoral Osteotomy Versus Isolated Autologous Chondrocyte Implantation

To compare clinical outcomes of patients undergoing isolated patellofemoral autologous chondrocyte implantation (ACI) and ACI combined with patellofemoral realignment. A systematic review was performed by use of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines/checklist. We searched PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), SportDiscus, and the Cochrane Central Register of Controlled Trials databases from 1946 through February 2012 to determine whether a difference exists in outcomes of combined ACI and osteotomy versus isolated ACI (minimum 2 years' follow-up). Studies were included only if outcomes were reported separately for both isolated ACI and combined ACI and osteotomy. All ACI generations were eligible for inclusion. Patellofemoral osteotomies eligible for inclusion were anteriorization, medialization, or anteromedialization. All patient-, limb-, and defect-specific characteristics were assessed. All reported clinical scores, radiographic and histologic outcomes, and complications/reoperations were analyzed. Risk of bias was assessed within all studies. Eleven studies (10 Level III or IV evidence) (366 subjects) were included. Of the defects treated, 78% were located on the patella and 22% on the trochlea. The mean subject age was 33.3 years. Twenty-three percent of subjects underwent concomitant osteotomy. The mean length of follow-up was 4.2 years. Significant (P < .05) improvements in patients undergoing both isolated ACI and combined ACI and osteotomy for patellofemoral chondral defects were observed in all studies. Three studies directly compared isolated ACI and combined ACI and osteotomy, with significantly (P < .05) greater improvements shown in patients undergoing combined osteotomy and ACI (International Knee Documentation Committee subjective score, Lysholm score, Knee Injury and Osteoarthritis Outcome Score, Tegner score, modified Cincinnati score, Short Form 12 score, and Short Form 36 score). There was no significant difference between groups in the rate of postoperative complications overall. This review showed statistically significant improvements in patients undergoing both isolated ACI and ACI combined with osteotomy for patellofemoral chondral defects in all studies. When individual studies compared these 2 groups (3 studies), significantly greater improvements in multiple clinical outcomes in subjects undergoing ACI combined with osteotomy were observed. There was no significant difference in the rate of total complications between groups. Level IV, systematic review of studies with minimum Level IV evidence, retrospective case series.

Paper 135: Autologous Chondrocyte Implantation for the Treatment of Patellofemoral Chondral Defects

Paper 135: Autologous Chondrocyte Implantation for the Treatment of Patellofemoral Chondral Defects

Characterized Chondrocyte Implantation in the Patellofemoral Joint

Background: Autologous chondrocyte implantation (ACI) is an accepted treatment option for selected condylar cartilage defects in the knee. Results for patellofemoral chondral defects have been less favorable. Hypothesis: Autologous chondrocyte implantation with characterized chondrocytes will result in clinically relevant improvement in patellofemoral lesions. Study Design: Case series; Level of evidence, 4. Methods: Patients with symptomatic patellofemoral full-thickness cartilage lesions were treated with ACI using characterized chondrocytes (ChondroCelect) covered with a collagen type I membrane. Clinical outcome was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and a visual analog scale (VAS) for pain. Responders were defined using 5 categories (≥10 points and ≥20%, 30%, 50%, 70%) based on the KOOS and VAS. Treatment failure was defined as partial loosening of more than 20% of the graft with subsequent procedures to the subchondral bone. Results: Thirty-eight patients, with a mean defect size of 4.89 cm2 (range, 1.5-11 cm2), were treated for a patellar defect (n = 28), trochlear defect (n = 7), or a kissing lesion (trochlea and patella; n = 3). The minimum follow-up period was 24 months (mean, 37 months; range, 24-72 months). Treated patients showed statistically significant improvements in the KOOS (at 12, 18, 24, 36, and 48 months) and VAS (at the same time points) compared with pretreatment for each time point. Responder analysis identified approximately 84% of patients with a clinically relevant improvement greater than 10 points at 3 years. Treatment failure was observed in 5 patients. The most commonly reported adverse events were joint crepitation (n = 18) and arthrofibrosis (n = 7). No relationship could be found between clinical outcome and anatomic characteristics of the patellofemoral joint, lesion size and site, time since onset, or age. Nine patients required additional surgery: 6 because of persistent symptoms and 3 for hardware removal. Conclusion: Characterized chondrocyte implantation resulted in statistically significant and clinically relevant improvement over time. These results add to the evidence demonstrating that ACI is a valuable cartilage repair technique for patellofemoral lesions.

Sensitivity of Magnetic Resonance Imaging for Detection of Patellofemoral Articular Cartilage Defects

Chondral defects within the patellofemoral compartment are common and lack the ability to heal on their own. Early detection of these lesions with a noninvasive modality would be beneficial in delaying or preventing their possible progression to osteoarthritis. We hypothesized that magnetic resonance imaging (MRI) is a sensitive, specific, and accurate imaging modality for the detection of patellofemoral chondral defects with substantial interobserver reliability and that MRI has a higher sensitivity, specificity, and accuracy for detecting patellar defects than trochlear defects. A systematic review of multiple medical databases was performed by use of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol. Analysis of studies that reported diagnostic performance of MRI in the assessment of patellofemoral chondral defects (patella and trochlea), using arthroscopy as the reference gold standard, was performed. Sensitivity, specificity, accuracy, and interobserver reliability were reported. Significant heterogeneity across studies precluded meta-analysis. MRI was more sensitive in detection of patellar (87%) versus trochlear (72%) defects. MRI was similarly specific for patellar (86%) and trochlear (89%) defects. MRI was similarly accurate for patellar (84%) and trochlear (83%) defects. Interobserver agreement was substantial to almost perfect for both patellar and trochlear defects. MRI is a highly sensitive, specific, and accurate noninvasive diagnostic modality for the detection of chondral defects in the patellofemoral compartment of the knee, using arthroscopy as the reference gold standard. Although there was wide variability in the statistical parameters assessed, MRI was more sensitive for detection of patellar versus trochlear defects and similarly specific and accurate for patellar and trochlear defects. Interobserver reliability is substantial to near perfect in the assessment of these lesions, without a significant difference between patellar and trochlear defects. Use of MRI may allow early detection of chondral defects within the patellofemoral compartment, enabling clinicians to adopt strategies to delay or prevent progression to osteoarthritis. Level III, systematic review of Level I, II, and III studies.

Patellofemoral Chondral Defects Treated with 2nd Generation ACI: A Clinical Review at 6 Years (SS-60)

Patellofemoral lesions are difficult to treat, however, authors hypothesized that Second generation ACI could be a viable treatment for patellofemoral Grade III-IV chondral lesions. The aim of this study was to test the efficacy of Second generation ACI in treating full-thickness patellofemoral defects and report results at six years. In this prospective non-randomized controlled study, 34 patients with patellofemoral chondral lesions, mean size of 4.45 cm2, were followed up. Lesions were classified as ICRS grade IV A or B (76.47%), grade IIIC (14.70%) and secondary to OCD (8.82%). Grafts were implanted through a mini-incision approach (25) or arthroscopically (9). Results were evaluated using the ICRS IKDC 2000 subjective and objective scores, EuroQol VAS, and Tegner scores at pre-op, 2 and 6 yrs. Statistical analysis was performed using the paired T test and Wilcoxon signed rank test. All scores demonstrated a statistically significant improvement (P < .0001) at 6 years from pre-op. Objective preoperative data improved from 8/34 (23.52%) with IKDC A or B scores to 30/34 (88.22%) IKDC A or B scores at 6 years. Mean IKDC subjective scores improved from 46.09 points preoperatively to 70.39 points 6 years after implantation. Tegner improved from 2.56 to 4.68. EQ VAS scores improved from 54.81 to 78.24. Second generation ACI can be a viable treatment for patellofemoral chondral lesions. Long-term investigations (10 years) are needed to determine the durability of the repair produced with this technique.

Results of Arthroscopic and Minimally Invasive Techniques for the Management of Patellofemoral Chondral Defects Using a Hyaluronan-Based Scaffold (SS-22)

Results of Arthroscopic and Minimally Invasive Techniques for the Management of Patellofemoral Chondral Defects Using a Hyaluronan-Based Scaffold (SS-22)