Long-term Assessment of Subchondral Bone Changes and Intralesional Bony Overgrowth After Third-Generation Autologous Chondrocyte Implantation: A Retrospective Study.

BACKGROUND: There is an increasing interest in subchondral bone changes and intralesional bony overgrowth (ILBO) after cartilage repair. Their clinical and predictive relevance is unclear and debated. PURPOSE: To evaluate the long-term development of ILBO and bone marrow edema-like signals (BMELSs) after autologous chondrocyte implantation (ACI) treatment of cartilage defects to find any predictive factors for their appearance. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 130 patients with 160 cartilage defects in the knee joint treated with third-generation ACI were included in this study. Radiological scores as the MOCART (magnetic resonance observation of cartilage repair tissue), the MOCART 2.0 and the 3D-MOCART using magnetic resonance imaging (MRI), and patient-reported outcome measures such as the Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, Noyes Sports Activity Rating Scale (NSARS) score, and Tegner Activity Scale (TAS) score were evaluated between 60 and 120 months (mean, 88 months) postoperatively. The radiological evaluation focused on the occurrence and size of subchondral bone changes, BMELSs, and ILBO during short-, medium-, and long-term follow-up. RESULTS: In long-term evaluation of clinical data, the IKDC score increased preoperatively from 36 to 64, the overall KOOS from 43 to 64, the NSARS score from 30 to 67, and the TAS score from 2 to 3.7. The mean MOCART score was 73; the MOCART 2.0, 69; and the 3D-MOCART, 69 and 70. The authors observed ILBO in 77% and BMELSs in 74% of patients after 60 to 120 months. Previous cartilage surgeries and osteochondral defect buildup showed higher rates of these abnormalities. Early lesions of the subchondral lamina did not predict ILBO in long-term follow-up, but BMELSs predicted later appearance with decreasing size. CONCLUSION: Subchondral changes frequently appeared in long-term MRI evaluation of patients after ACI. BMELSs showed a decreasing diameter over the years, while the size of ILBO increased in the later follow-ups. These findings did not affect the clinical outcome in the study population. However, osteoarthritis is likely to progress. The degenerative effect and influence on longer-term outcomes needs to be clarified in future studies.

The influence of advanced age in bone healing after intramedullary limb lengthening.

BACKGROUND: Distraction osteogenesis with an intramedullary motorized nail is a well-established method to treat leg length discrepancy (LLD). The complex process of bone consolidation is affected by age, location, comorbidities, smoking and gender. The purpose of this case series was to investigate influencing factors in bone regeneration after intramedullary callus distraction. HYPOTHESIS: Advanced age influences the outcome of intramedullary limb lengthening. PATIENTS AND METHODS: This retrospective analysis included 19 patients after intramedullary telescopic nailing (PRECICE) on the lower limb with a mean age of 43 years. Bone healing was assessed by distraction and healing parameters such as distraction-consolidation time (DCT), distraction index (DI), healing index (HI), lengthening index (LI), and consolidation index (CI). RESULTS: Confounding factors such as smoking, previous operations on the treated bone, but also the occurrence of complications, and the number of revision surgeries are independent of the patients' age. Younger patients showed a shorter distraction distance, a lower DCT, a lower DI, a higher HI, and a higher CI than older patients. The complication rate requiring nail exchange was higher among the younger patients. Bony healing was observed in all age groups treated with a telescopic nail regardless of age. CONCLUSION: Advanced age did not influence bone healing or complication rate in intramedullary lengthening. However, the conclusion is limited by the small patient number. LEVEL OF EVIDENCE: IV; Case control study.

Computed Tomography in Limb Salvage and Deformity Correction-3D Assessment, Indications, Radiation Exposure, and Safety Considerations.

Computed tomography (CT) is an essential tool in orthopedic surgery but is known to be a method with that entails radiation exposure. CT increases the risk of developing fatal cancer, which should not be underestimated. However, patients with bone defects and/or deformities must frequently undergo numerous investigations during their treatment. CT is used for surgical planning, evaluating callus maturation, alignment measurement, length measurement, torsion measurement, and angiography. This study explores the indications in CT scans for limb lengthening and deformity correction and estimates the effective radiation dose. These results should help avoid unnecessary radiation exposure by narrowing the examination field and by providing explicit scanning indications. For this study, 19 posttraumatic patients were included after the bone reconstruction of 21 lower limbs. All patients underwent CT examinations during or after treatment with an external ring fixator. The mean effective dose was 3.27 mSv, with a mean cancer risk of 1:117,014. The effective dose depended on the location and indication of measurement, with a mean dose of 0.04 mSv at the ankle up to 6.8 mSv (or higher) for vascular depictions. CT evaluation, with or without 3D reconstruction, is a crucial tool in complex bone reconstruction and deformity treatments. Therefore, strict indications are necessary to reduce radiation exposure-especially in young patients-without compromising the management of their patients.

Implant failure after externally magnetic-controlled nail lengthening.

The number of intramedullary procedures to treat leg length discrepancy (LLD) has risen in the past decade and this has led to increased complications such as nail breakage. The aim of this study was to reveal our experience with implant failure after externally magnetic-controlled telescopic bone lengthening. We observed nail-breakage in 4 out of 24 patients (16.7%) after 6 to 15 months (median 13.5 months) following lower limb lengthening for LLD due to non-union or insufficient bone healing. Three femora and one tibia were treated in one posttraumatic and three congenital cases. Three out of the four patients had an elevated Charleston Comorbidity Index (CCI). Revision surgery involved removal of the broken nail and implantation of a trauma nail. At final follow-up all patients showed subjective satisfaction, achievement of desired lengthening with complete bone healing. Based on our results no unequivocal risk factor including number of previous surgeries, comorbidities and age was identified. In cases of delayed bone formation, early revision surgery with an exchange to a trauma nail has to be considered to prevent breakage of the intramedullary telescopic device.

Bone reconstruction: Subjective evaluation and objective analysis based on conventional digital X-rays - a retrospective evaluation.

BACKGROUND: Various approaches have been used to evaluate callus stiffness in distraction osteogenesis. This assessment becomes even more critical as inadequate corticalization and premature removal of the frame lead to bending, refracture, and loss of length. This study aimed to verify the objective Pixel Value Ratio (PVR) and define an evaluation scheme to assess callus tissue development during internal and external bone lengthening. HYPOTHESIS: There are no differences between subjective parameters and objective evaluation for external and internal bone lengthening. PATIENTS AND METHODS: We included 24 patients in this retrospective study, treated by distraction osteogenesis of the lower limb. Ten patients were treated with external ring fixators and 14 with intramedullary lengthening devices. The minimum distraction distance was 3cm. Callus tissue was evaluated with the PVR, using digital X-rays during and after treatment. We combined this method with subjective evaluation parameters, including the continuity, signal intensity, and the regeneration tissue's homogeneity, presented in the X-ray Evaluation System for Distraction Osteogenesis (XESDO). RESULTS: The subjective evaluation showed an increase of continuity and signal-intensity between 4th postoperative weeks and complete healing with significant differences between the external and internal groups for homogeneity only after four weeks and for all parameters at 3C (p<0.05). The PVR showed an increase during consolidation with values between 0.7 and 1.0 for both groups with almost perfect interobserver agreement. Significant lower values were found in the anterior tibial cases. CONCLUSION: PVR appears to be a practical tool for radiological evaluation of callus tissue development. In combination with the newly introduced XESDO and the surgeon's experience, these methods can be helpful for decisions during all phases of distraction osteogenesis. It is important for adapting alignment or distraction-rate, as various potential complications can be detected early. However, further studies are necessary to assess the image-based determination of callus tissue stability. LEVEL OF EVIDENCE: III; cohort study.

Clinical evaluation after matrix-associated autologous chondrocyte transplantation : a comparison of four different graft types.

AIMS: The aim of this retrospective study was to determine if there are differences in short-term clinical outcomes among four different types of matrix-associated autologous chondrocyte transplantation (MACT). METHODS: A total of 88 patients (mean age 34 years (SD 10.03), mean BMI 25 kg/m2 (SD 3.51)) with full-thickness chondral lesions of the tibiofemoral joint who underwent MACT were included in this study. Clinical examinations were performed preoperatively and 24 months after transplantation. Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC) Subjective Knee Form, the Brittberg score, the Tegner Activity Scale, and the visual analogue scale (VAS) for pain. The Kruskal-Wallis test by ranks was used to compare the clinical scores of the different transplant types. RESULTS: The mean defect size of the tibiofemoral joint compartment was 4.28 cm2 (SD 1.70). In total, 11 patients (12.6%) underwent transplantation with Chondro-Gide (matrix-associated autologous chondrocyte implantation (MACI)), 40 patients (46.0%) with Hyalograft C (HYAFF), 21 patients (24.1%) with Cartilage Regeneration System (CaReS), and 15 patients (17.2%) with NOVOCART 3D. The mean IKDC Subjective Knee Form score improved from 35.71 (SD 6.44) preoperatively to 75.26 (SD 18.36) after 24 months postoperatively in the Hyalograft group, from 35.94 (SD 10.29) to 71.57 (SD 16.31) in the Chondro-Gide (MACI) group, from 37.06 (SD 5.42) to 71.49 (SD 6.76) in the NOVOCART 3D group, and from 45.05 (SD 15.83) to 70.33 (SD 19.65) in the CaReS group. Similar improvements were observed in the VAS and Brittberg scores. CONCLUSION: Two years postoperatively, there were no significant differences in terms of outcomes. Our data demonstrated that MACT, regardless of the implants used, resulted in good clinical improvement two years after transplantation for localized tibiofemoral defects. Cite this article: Bone Joint Res 2021;10(7):370-379.

Third-Generation Autologous Chondrocyte Implantation at the Knee Joint Using the Igor Scaffold: A Case Series With 2-Year Follow-up.

BACKGROUND: For large, locally restricted cartilage defects in young patients, third-generation matrix-supported autologous chondrocyte implantation (ACI) with a variety of scaffolds has shown good mid- to long-term results. PURPOSE/HYPOTHESIS: This study aimed to monitor the clinical and radiological outcomes of patients who received ACI at the knee joint using the Igor scaffold (IGOR-Institute for Tissue and Organ Reconstruction) at 2-year follow-up. Our hypothesis was that there would be improvements in postoperative subjective scores and cartilage repair tissue quality. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 21 patients (12 male and 9 female) were available for 2-year follow-up after third-generation ACI using the Igor scaffold. All were clinically assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale, Brittberg score, International Knee Documentation Committee (IKDC) Subjective Knee Form, Noyes Sports Activity Rating Scale, and visual analog scale for pain. For morphological evaluation, the magnetic resonance observation of cartilage repair tissue (MOCART) and MOCART 2.0 scores were calculated using 3-T magnetic resonance imaging performed at 3, 6, 12, and 24 months postoperatively. Results were compared between baseline and 24 months postoperatively. RESULTS: After 2 years, the clinical and radiological scores showed good to excellent results in the majority of patients. On the IKDC, 10 patients were graded as excellent, 4 as good, 5 as fair, and 2 as severe; on the KOOS, 7 patients were graded as excellent, 8 as good, 4 as fair, and 2 as severe. From baseline to latest follow-up, visual analog scale pain scores decreased from 5.6 ± 3.2 (mean ± SD) to 1.5 ± 2; KOOS results increased from 51 ± 20.7 to 75.2 ± 15.4; and the Tegner score improved from 2.2 ± 1.8 to 4.3 ± 1.3. The MOCART and MOCART 2.0 scores were comparable at 2-year follow-up, with mean values of 74 ± 10 and 78 ± 13, respectively. Satisfactory filling and integration were found in 90.5%. Overall, 16 of 21 patients (76.1%) were satisfied with the surgery and would undergo the procedure again. CONCLUSION: Third-generation ACI using the Igor scaffold showed improvements in clinical and radiological results that were comparable with other scaffolds for patients with large traumatic or degenerative cartilage defects. Patients reported a decrease in pain and an increase in activity, with the majority reporting good results.

Intramedullary Bone Lengthening Following Preceding Hip Surgery-A Case Series.

Limb length discrepancy (LLD) is a common problem after joint-preserving hip surgeries, hip dysplasia, and hip deformities. Limping, pain, sciatica, paresthesia, and hip instability are common clinical findings and may necessitate limb-lengthening procedures. The study included five patients (two female and three male, mean age of 28 years (20-49; SD: 12)) with symptomatic limb length discrepancy greater than 2.5 cm (mean: 3.6 cm) after total hip arthroplasty (THA), hip dysplasia, or post-traumatic hip surgery. They underwent either ipsi- or contralateral intramedullary limb-lengthening surgeries using the PRECICE™ telescopic nail. All patients achieved complete bone healing and correction of the pelvic obliquity after intramedullary lengthening. None of the patients had a loss of proximal or distal joint motion. The mean distraction-consolidation time (DCT) was 3.8 months, the distraction index (DI) 0.7 mm/day, the lengthening index (LI) 1.8 months/cm, the consolidation index (CI) 49.2 days/cm, the healing index (HI) 1.1 months/cm, and the modified healing index (HI*) 34 days/cm. Intramedullary limb lengthening after LLD in cases of hip dysplasia, hip deformity, and various kinds of hip surgery is a useful and safe procedure in young patients to achieve equal limb length. No functional impairment of the preceded hip surgery was seen.

Anatomical Considerations of Intramedullary Humeral Nailing and Lengthening.

Intramedullary lengthening, in cases of extensive humeral shortening, offers the advantages of preventing external-fixator-associated problems. The humeral cavity, as the main parameter in nailing, however, has been neglected in recent literature. It was hypothesized that available implants might be too large and therefore increase the risk of intraoperative fractures. The aim of this cross-sectional study was to describe the humeral canal and how it might affect the choice of implant and the surgical approach. Thirty humeri (15 female, 15 male) from clinical patients and anatomical specimens were studied. Specifically, the medullary cavity width (MCW), cortical thickness (CoT), and the course of the medullary canal were examined. The smallest MCW diameters were found at the distal third of the humeral shaft with mean diameters of 10.15 ± 1.96 mm. CoTs of female humeri were significantly smaller than those of male humeri (p < 0.001). The mean angles of the pro- and recurvatum were 4.01 ± 1.68° and 10.03 ± 2.25°, and the mean valgus bending was 3.37 ± 1.58°. Before implanting a straight lengthening nail into a doubly curved humerus, X-rays and, in selected cases, CT-scans should be performed. The unique size and course of the humeral canal favors an antegrade approach in cases of intramedullary lengthening.

Innovative Technique in Extended Intramedullary Humeral Lengthening: A Case Report.

CASE: Intramedullary humeral lengthening is still a very uncommon procedure to treat humeral limb length discrepancy (LLD). This approach has various advantages compared with external devices but is limited in its ability to lengthen bones because of the length of the telescopic nail. This case report describes a middle-aged patient with a short right humerus secondary to a childhood growth plate injury that was successfully lengthened with an off-label application of a tibial distracting device. Hereby, a novel treatment technique with unlocking, backwinding, and reinterlocking of the telescopic nail for extended humeral distraction was performed. CONCLUSIONS: Extended intramedullary humeral lengthening with unlocking, backwinding, and reinterlocking of the nail is a cost-effective, minimally invasive procedure in cases of massive humeral LLD with limitations in the distraction capacity of the telescopic nail.

Traumatic periimplant fracture after nail arthrodesis of the knee in a limb reconstruction case.

Many principles of bone reconstruction were successfully applied in this unique case of a 1.92m (6 ft 3 in.) tall 15 year old boy with intercalary leg amputation. This patient suffered from a 26 cm (10.2 in.) bone loss of his left distal femur and severe soft tissue damage with an irreparable extensor mechanism after motor cycle accident. After periimplant fracture below the knee arthrodesis nail, definite treatment consisted of implant exchange to an 870 mm (34.3 in.) long custom made nail, which is to our knowledge the longest implanted arthrodesis nail in literature. Therefore the aim of the study was to present our treatment strategies and pitfalls after traumatic periimplant arthrodesis nail fracture in an unusual case of limb reconstruction.

[Intramedullary upper arm lengthening]. / Intramedulläre Oberarmverlängerung.

The new technology of motorized intramedullary telescopic nails has simplified the treatment for upper limb lengthening surgery. Improved patient comfort, low infection rates and absence of fractures in the regenerated bone are contrasted by the limitations of the methods, such as a current maximum distraction of 5cm and the fact that they cannot be used when the growth plates are still open.

Matrix Production Affects MRI Outcomes After Matrix-Associated Autologous Chondrocyte Transplantation in the Knee.

BACKGROUND: Matrix-associated autologous chondrocyte transplantation (MACT) has been an effective therapy for large, full-thickness cartilage lesions for years. However, little is known about how graft maturation is affected by characteristics of transplanted chondrocytes. PURPOSE: To investigate the influence of gene expression of chondrocytes at the time of transplantation on MRI outcomes up to 2 years after MACT. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study included 25 patients with 27 symptomatic traumatic defects of articular cartilage, who had undergone MACT in the knee. Postoperative MRI examinations were conducted at 3, 6, 12, and 24 months after surgery. Biochemical graft maturation was assessed by measuring T2 relaxation time values of the transplant and healthy native cartilage areas. The MOCART (magnetic resonance observation of cartilage repair tissue) score was used to evaluate the morphological quality of regeneration tissue. Gene expression (collagen type I, collagen type II, aggrecan, versican, and interleukin-1ß) was determined by real-time polymerase chain reaction (PCR) in transplant residuals at the time point of transplantation and was correlated with MRI outcomes using Spearman's rank correlation coefficient. A Friedman test with post hoc analysis (Wilcoxon signed rank test) conducted with a Bonferroni correction was applied to compare scores at different time points. RESULTS: T2 relaxation time of regeneration tissue improved from a mean ± SD of 74.6 ± 20.1 milliseconds at 3 months to 47.9 ±13.3 milliseconds at 24 months ( P < .003). These values were similar to the T2 relaxation times of the native surrounding cartilage (50.9 ± 15 ms). The calculated T2 index (ratio of regeneration tissue to native cartilage) improved from 1.63 ± 0.76 at 3 months to 1.0 ± 0.4 at 24 months ( P < .011). The MOCART score increased from 51.6 ± 15 points to 72.4 ± 12.2 points ( P < .001). Improvement of the T2 index over time significantly correlated with aggrecan, COL1A1, COL2A1, and versican expression ( rs = 0.9, P < .001; rs = 0.674, P < .012; rs = 0.553, P < .05; and rs = 0.575, P < .04, respectively). No correlation was found for IL-1ß. CONCLUSION: These data demonstrate that matrix production in transplanted chondrocytes affects maturation of MACT grafts in MRI 2 years after surgery.

Tibio-talo-calcaneal fusion after limb salvage procedures-A retrospective study.

BACKGROUND: The treatment of limb threatening trauma on the distal tibia or hindfoot often results in posttraumatic osteoarthritis requiring tibiotalocalcaneal (TTC) arthrodesis. The purpose of this study was to present a case series of patients undergoing various techniques of joint fusion after bone reconstruction and deformity correction as a salvage procedure. The study should help trauma surgeons making decisions in limb salvage and deformity correction in complex lower leg and foot injuries by presenting options and treatment strategies. PATIENTS AND METHODS: Eight patients (4 male, 4 female) after TTC arthrodesis as a definitive procedure after polytrauma or monotrauma involving the distal tibia or hindfoot were the subject of this retrospective analysis. We included patients treated by external ring fixation (1 case), external fixation+wires (1 case), external fixation+screws (1 case) and intramedullary nailing (1 ante- and 5 retrograde; 1 bilateral, 4 unilateral). Initial trauma included open fractures, subtotal foot amputations and closed fractures with failed osteosynthesis and failed ankle joint replacement. Bone defects were treated with callus distraction or segment transport in 5 cases. Various angles were measured to assess foot deformities in the lateral radiographic view and clinical results were presented. RESULTS: Independent, pain-free mobilisation with full weight bearing was achieved in all 8 patients. In terms of subjective outcome, all patients reported a highly satisfying result. Complete consolidation at the fusion site was achieved in 8 out of 9 cases with a high rate of adjacent joint arthritis. Angles measures in the lateral radiographs showed values typical for a pes cavus tendency. CONCLUSION: Tibio-talo-calcaneal (TTC) arthrodesis is a viable treatment option for severe post traumatic arthritis and deformity of the ankle and subtalar joint. Despite bad bone quality retrograde intramedullary nailing does provide acceptable results providing stability, low invasiveness and low infection rate. Simultaneous TTC-fusion and tibial lengthening using the Ilizarov ring fixator may be necessary when the surgeon is confronted with large bone defects - often followed by a nailing after lengthening procedure. This study shows that limb preservation after limb threatening trauma with hindfoot injury and multiple fractures of the lower extremity is recommenced as the method of choice with reasonable clinical results. LEVEL OF EVIDENCE: IV, Case series.

Intramedullary magnetically actuated limb lengthening in a patient with congenital humeral limb shortening.

The treatment of leg length discrepancy has become a common procedure in orthopaedic surgery. However, lengthening of humeral deformities is still infrequent. The purpose of this case report was to present humeral lengthening with a new intramedullary lengthening device (PRECICE® P2 for tibia) in a 32 year old female patient with congenital shortening. Hereby the telescopic device presents a promising tool for humeral limb lengthening with excellent outcome at short-term in this case.

Cartilage evaluation with biochemical MR imaging using in vivo Knee compression at 3T-comparison of patients after cartilage repair with healthy volunteers.

Magnetic resonance (MR) transverse relaxation time (T2) mapping has been frequently used to evaluate collagen content and its organization. In this study, MR T2 mapping, using the multi-slice, multi-echo Carr-Purcell-Meiboom-Gill technique, was performed in volunteers and patients after matrix-associated autologous chondrocyte transplantation (MACT) under unloading and loading conditions with an MR-compatible compression device. In the volunteer study, a statistically significant decrease in the cartilage MR T2 values was observed during the loading phase when compared to the initial load-free measurement. During the recovery period, a statistically significant increase in the T2 values was found in the central superficial layer (p=0.001), the central deep layer (p=0.005), the posterior deep layer (p=0.001), and in the tibia superficial layer (p=0.01) when compared to measurements under loading. In patients after MACT, during unloading or loading conditions, statistically significant changes in T2 values were observed in the transplant deep zone (p=0.005), in the posterior deep zone (p=0.004), and in the tibia superficial zone (p=0.012). The results of this study show that MR T2 mapping under loading conditions may provide additional information about cartilage repair tissue composition and organization during the postoperative follow-up, and may help to evaluate the efficacy of cartilage-repair surgery techniques.

Effect of accelerated weightbearing after matrix-associated autologous chondrocyte implantation on the femoral condyle: a prospective, randomized controlled study presenting MRI-based and clinical outcomes after 5 years.

BACKGROUND: Long-term effects of different weightbearing (WB) modalities after matrix-associated autologous chondrocyte implantation (MACI) on changes in knee articular cartilage and clinical outcomes are needed to establish more evidence-based recommendations for postoperative rehabilitation. HYPOTHESIS: There will be no differences between accelerated WB compared with delayed WB regarding knee articular cartilage or patient self-reported knee function or activity level 5 years after MACI. Furthermore, significant correlations between magnetic resonance imaging (MRI)-based outcomes and patient-reported outcome measures 5 years postoperatively will exist. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: After MACI, 31 patients (23 male, 8 female) were randomly assigned to the accelerated WB group (AWB group) or to the delayed WB group (DWB group). With the exception of time and increase to full WB, both groups underwent the same rehabilitation program. The AWB group was allowed full WB after 6 weeks and the DWB group after 10 weeks. Assessments were performed 3 months, 2 years, and 5 years postoperatively, but this long-term follow-up study only included changes from 2 to 5 years postoperatively. The magnetic resonance observation of cartilage repair tissue (MOCART) score (primary outcome), the MRI-based variables of bone edema and effusion, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner scale were included. In addition, the association between MRI-based outcomes and the KOOS at 5 years postoperatively was investigated. RESULTS: There was a significant decrease in the MOCART score and a significant increase in bone edema 2 and 5 years postoperatively but no significant group differences. The only significant correlation between the MRI-based variables and the KOOS was found for bone edema and the KOOS subscale of pain (r=-0.435, P<.05) at 5-year follow-up. CONCLUSION: There were no significant differences in the MRI-based or clinical outcomes between the AWB group and DWB group 5 years after MACI. While the clinical outcomes remained stable, a decline of the MRI-based findings was observed between 2 and 5 years postoperatively. Furthermore, a significant association between bone edema and pain was found. No occurrence of unintended effects was observed.

Clinical and radiological long-term outcomes after matrix-induced autologous chondrocyte transplantation: a prospective follow-up at a minimum of 10 years.

BACKGROUND: It is unclear whether matrix-associated autologous chondrocyte transplantation (MACT) results in objective and subjective clinical improvements at 10 years after surgery. HYPOTHESIS: Matrix-associated autologous chondrocyte transplantation will result in clinical and radiological improvements in patients with symptomatic, traumatic chondral defects of the knee joint. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 16 patients with chondral defects of the knee were treated with MACT between November 2000 and April 2002 and evaluated for up to 10 years after the intervention. The International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner activity score, Brittberg score, Noyes sports activity rating scale, and visual analog scale (VAS) for pain as well as 3-T magnetic resonance imaging (MRI) using the magnetic resonance observation of cartilage repair tissue (MOCART) score and functional evaluation by the limb symmetry index (LSI) formed the basis of this study. The Friedman test and the Wilcoxon signed-rank test were performed for a comparison between all time points and 2 separate time points, respectively. If significant differences were revealed, a Bonferroni adjustment to the α level was applied so that P values <.007 (<.05/7) were regarded as significant in the paired comparisons. RESULTS: Significant improvements (P < .05) from baseline to 120 months postoperatively were observed for the IKDC score (mean, 44.1 ± 26.9 to 59.0 ± 27.4), Noyes sports activity rating score (mean, 37.7 ± 30.1 to 62.1 ± 31.3), and KOOS Quality of Life and Pain subscores, whereas no statistically significant improvement was detected for the Brittberg score, Tegner activity score, or VAS score. After 5 years, a slight downward tendency of all clinical scores was evident. After 10 years, the mean MOCART score was 70.4 ± 16.1. Complete filling of the defect was observed in 73.9% of cases, and osteophytes were present in 78.3%. In 65.2% of the cases, a subchondral bone edema <1 cm was visible, whereas in 21.7% of the cases, a subchondral bone edema >1 cm was seen. The mean LSI for the single-legged hop test was 95.6% ± 16.2% and for the triple hop test for distance was 91.3% ± 12.2%. The mean VAS score for self-perceived stability was 60.2 ± 3.5 (range, 0-9.5) for the injured and 60.7 ± 3.8 (range, 0-10) for the uninjured leg. No adhesions or effusions were seen regarding the clinical and radiological outcomes. CONCLUSION: The significantly improved results on 3 outcome measures after 10 years suggest that MACT represents a suitable option in the treatment of local cartilage defects in the knee.

Results 2 Years After Matrix-Associated Autologous Chondrocyte Transplantation Using the Novocart 3D Scaffold: An Analysis of Clinical and Radiological Data.

BACKGROUND: A range of scaffolds is available from various manufacturers for cartilage repair through matrix-associated autologous chondrocyte transplantation (MACT), with good medium- to long-term results. PURPOSE: To evaluate clinical and magnetic resonance imaging (MRI) outcomes 2 years after MACT on the knee joint using the Novocart 3D scaffold based on a bilayered collagen type I sponge. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Of 28 initial patients, 23 were clinically and radiologically evaluated 24 months after transplantation. Indications for MACT were chondral or osteochondral lesions on the knee joint with a defect size >2 cm2, no instability, and no malalignment (axis deviation <5°). Then, MRI was performed on a 3-T scanner to assess the magnetic resonance observation of cartilage repair tissue (MOCART) and 3-dimensional (3D) MOCART scores. A variety of subjective scores (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Noyes sports activity rating scale, Tegner activity scale, and visual analog scale [VAS] for pain) were used for clinical evaluation. RESULTS: Two years after MACT, the MRI evaluation showed a mean MOCART score of 73.2 ± 12.4 and a 3D MOCART score of 73.4 ± 9.7. Clinical results showed mean values of 69.8 ± 15.2 for the IKDC; 51.6 ± 21.2, 86.5 ± 13.9, 54.5 ± 23.6, 65.0 ± 8.0, and 91.5 ± 10.6 for the KOOS subscales (Quality of Life, Pain, Sports and Recreation, Symptoms, and Activities of Daily Living, respectively); 77.5 ± 12.7 for the Noyes scale; 4.4 ± 1.6 for the Tegner activity scale; and 1.8 ± 1.7 for the VAS, with statistically significant improvement in all scores other than KOOS-Symptoms. CONCLUSION: Undergoing MACT using the Novocart 3D scaffold is an applicable method to treat large focal chondral and osteochondral defects, with good short-term clinical and radiological results.

Influence of cell differentiation and IL-1ß expression on clinical outcomes after matrix-associated chondrocyte transplantation.

BACKGROUND: Several patient- and defect-specific factors influencing clinical outcomes after matrix-associated chondrocyte transplantation (MACT) have been identified, including the patient's age, location of the defect, or duration of symptoms before surgery. Little is known, however, about the influence of cell-specific characteristics on clinical results after transplantation. PURPOSE: The aim of the present study was to investigate the influence of cell differentiation and interleukin-1 ß (IL-1ß) expression on clinical outcomes up to 5 years after MACT. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-seven patients who underwent MACT of the tibiofemoral joint area of the knee were included in this study. Clinical assessments were performed preoperatively as well as 6, 12, 24, and 60 months after transplantation by using the following scores: the Knee injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee (IKDC) Subjective Knee Form, the Noyes sports activity rating scale, the Brittberg clinical score, and a visual analog scale (VAS) for pain. The quality of repair tissue was assessed by magnetic resonance imaging using the magnetic resonance observation of cartilage repair tissue (MOCART) score at 1 and 5 years. Cell differentiation (defined as collagen type II:type I expression ratio), aggrecan, and IL-1ß expression were determined by real-time polymerase chain reaction in transplant residuals and were correlated with clinical outcomes. RESULTS: The largest improvements in clinical scores were found during the first year. Two years postoperatively, a stable improvement was reached until 5 years after transplantation, with a mean IKDC score of 34.4 ± 8.6 preoperatively to 77.9 ± 16 after 24 months (P < .001). Cell differentiation showed a significant positive correlation with nearly all clinical scores at different time points, especially after 12 months (P < .05). IL-1ß expression negatively influenced clinical outcomes at 24 months (Brittberg score) and 60 months (Brittberg and VAS scores) after surgery (P < .05). No correlation was found between the MOCART score and clinical outcomes or gene expression. CONCLUSION: Our data demonstrate that cell differentiation and IL-1ß expression influence clinical outcomes up to 5 years after MACT.