Clinical and MRI evaluation of medium- to long-term results after autologous osteochondral transplantation (OCT) in the knee joint

Purpose

Autologous osteochondral transplantation (OCT) is one of the surgical options currently used to treat cartilage defects. It is the only cartilage repair method that leads to a transfer of hyaline cartilage repair tissue. The purpose of this study was to evaluate the magnetic resonance observation of cartilage repair tissue (MOCART) score, the 3D MOCART score and various clinical scores in patients after OCT in knee joints.

Methods

Two women and eight men were evaluated 6–9 years (median 7.2 years) after OCT on the femoral condyle of the knee joint. All patients were evaluated by magnetic resonance imaging (MRI) measurement, using a 3.0 T Scanner with different cartilage-specific sequences. Clinical assessment included the knee injury and osteoarthritis outcome score (KOOS), the international knee documentation committee (IKDC) subjective knee form, the Noyes sport activity rating scale and the Tegner activity score. For MRI evaluation, the MOCART score and 3D MOCART score were applied.

Results

Clinical long-term results after OCT showed median values of 77 (range 35.7–71.4) for the IKDC; 50 (6.3–100), 66.7 (30.6–97.2), 65 (0–75), 57.1 (35.7–71.4) and 80.9 (30.9–100) for the KOOS subscales (quality of life, pain sports, symptoms and activity of daily living); 61.4 (22.3–86.2) for the Noyes scale; and 3 (0–6) for the Tegner activity score. The median MOCART score was 75 (30–90) after both 1 and 2 years and 57.5 (35–90) after 7 years, as assessed by different cartilage-specific sequences. The 3D MOCART score showed values of 70 (50–85) and 60 (50–80) in the two different isotropic sequences after 7 years.

Conclusion

The MOCART and 3D MOCART scores are applicable tools for patient follow-up after OCT. Post-operative follow-up assessments would also benefit from the inclusion of OCT-specific parameters. Long-term results after OCT reflect an impairment in clinical scores in the first 2 years with good results during follow-up. Stable conditions were observed between 2 and 7 years after surgery. The filling of the defects and the cartilage interface appeared good at MRI evaluation after the first 2 years, but cartilage loss was observed between the medium- and long-term follow-ups. Isotropic imaging with multiplanar reconstruction is useful for daily clinical use to assess bony cylinders in cartilage repair, especially in combination with the 3D MOCART.

Level of evidence

Retrospective therapeutic study, Level IV.     

Use of cell-free collagen type I matrix implants for the treatment of small cartilage defects in the knee: clinical and magnetic resonance imaging evaluation

Purpose

Articular cartilage defects of the knee are a common condition for which several repair techniques have been described. The aim of the present study was to assess medium-term results of a one-step procedure using a cell-free collagen type I matrix.

Methods

Fifteen patients with articular cartilage defects of the knee were treated with an 11-mm-diameter cell-free collagen type 1 matrix implant. The matrices were implanted in a press-fit manner into the defect after careful debridement down to the subchondral bone but without penetration of this margin. Follow-up examinations were carried out at 6 weeks, 6 months, and at 12, 24, 36, and 48 months after implantation. Clinical assessment included the visual analogue scale (VAS), the Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. Radiological assessment for graft attachment and tissue regeneration was performed using the magnetic observation of cartilage repair tissue (MOCART) score.

Results

A total of 15 patients (males: n = 6 and females: n = 9) with a mean age of 26.4 years (range 19–40) were treated. The mean VAS improved significantly when compared to the preoperative values (P < 0.05). Six weeks after implantation, IKDC values were slightly lower than the preoperative values (n.s.), but increased significantly at final follow-up (P < 0.05). At 24 months, there were no significant differences in the median Tegner score between the post-operative values and the preoperative values (n.s.). However, after 36 months, a significant improvement was noted that lasted at least up to 48 months (P < 0.05). The MOCART score improved consistently up to 4 years after implantation, with significant improvements already observed after 12 months (P < 0.05). No correlation between the clinical scores and the MOCART score could be perceived.

Conclusion

The present study showed that the use of cell-free collagen type I matrix implants led to a significant and durable improvement in all the clinical and imaging scores investigated 4 years after implantation.

Level of evidence

IV.     

Failed cartilage repair for early osteoarthritis defects: a biochemical, histological and immunohistochemical analysis of the repair tissue after treatment with marrow-stimulation techniques

Purpose

To examine the entire repair tissue resulting from marrow-stimulation techniques in patients with early osteoarthritis.

Methods

The repair tissue and adjacent articular cartilage after failed marrow-stimulation techniques (microfracture and Pridie drilling) of 5 patients (47–65 years old) with cartilage defects and radiographic early osteoarthritis (Kellgren–Lawrence grading 1 and 2) was removed during total joint arthroplasty (mean time until analysis: 8.8 months), analysed by histology, polarized light microscopy, immunohistochemistry, biochemistry and by histological score systems.

Results

Macroscopic cartilage repair assessment revealed ICRS grades of II (nearly normal) and III (abnormal). Cartilage defects were mostly completely filled with a fibrocartilaginous tissue that had small and large fissures. Cartilage-specific stains of the repair tissue were more intense than the surrounding native cartilage but reduced compared with normal articular cartilage. The subchondral bone was incompletely restored. A new tidemark was absent. The repair tissue always showed positive immunoreactivity for types II and X collagen, and was sometimes positive for type I collagen. Proteoglycan contents of the repair tissue were generally higher than of the surrounding cartilage. The repair tissue was always more cellular than the adjacent articular cartilage. Histological scoring of the repair tissue revealed a mean Sellers score of 17.6 ± 3.0 and an ICRS grading of 7–9.

Conclusion

Failed marrow stimulation of articular cartilage defects in patients with early osteoarthritis is characterized by fibrocartilaginous repair. The balance of cell number to extracellular matrix is shifted towards an increased cell number in this tissue. Articular cartilage repair did not reach the quality of normal hyaline articular cartilage.

Level of evidence

IV.     

Short-term outcome of the second generation characterized chondrocyte implantation for the treatment of cartilage lesions in the knee

Purpose

To evaluate short-term clinical and MRI outcome of the second generation characterized chondrocyte implantation (CCI) for the treatment of cartilage defects in the knee.

Methods

Thirty-two patients aged 15–51 years with single International Cartilage Repair Society (ICRS) grade III/IV symptomatic cartilage defects of different locations in the knee were treated with CCI using a synthetic collagen I/III membrane to cover the defect. Clinical outcome was measured over 36 months by the Knee injury and Osteoarthritis Outcome Score (KOOS) and Visual Analogue Scale (VAS) for pain. Serial magnetic resonance imaging (MRI) scans of 22 patients were scored using the original and modified Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) system.

Results

The patients included in this study showed a significant gradual clinical improvement after CCI. The MRI findings of this pilot study were considered to be promising. No signs of deterioration were observed. A complete or hypertrophic filling was observed in 76.5% of the cases at 24 months of follow-up. No preventive effect of an avital membrane on the occurrence of hypertrophic repair tissue was observed on MRI. Three failures were observed among the 32 patients until now (9.4%).

Conclusions

This investigation provided useful information on the efficacy of this treatment. The short-term clinical and MRI outcome are promising. Large-scale and long-term trials are mandatory to confirm the results and the reliability of this procedure.

Level of evidence

IV.     

Repair tissue quality after arthroscopic autologous collagen-induced chondrogenesis (ACIC) assessed via T2* mapping

Objective

A novel single-stage approach using arthroscopic microdrilling and atelocollagen/fibrin-gel application is employed for cartilage repair of the knee. The purpose of our study was to investigate the morphological and biochemical MRI outcome after this technique.

Materials and methods

A retrospective case series of ten patients (mean age 45 years) with symptomatic chondral defects in the knee who were treated arthroscopically with microdrilling and atelocollagen application was analyzed. All defects were ICRS grade III or IV and the sizes were 2–8 cm² intra-operatively. All patients underwent morphological MRI and T2-star mapping at 1.5 T at 1-year follow-up. The magnetic resonance observation of cartilage repair tissue (MOCART) score was assessed. T2* relaxation time values of repair tissue and a healthy native cartilage area was assessed by means of region of interest analysis on the T2* maps.

Results

The mean MOCART score at 1-year follow-up was 71.7?±?21.0 ranging from 25 to 95. The mean T2* relaxation times were 30.6?±?11.3 ms and 28.8?±?6.8 ms for the repair tissue and surrounding native cartilage, respectively. The T2* ratio between the repair tissue and native cartilage was 105 %?±?30 %, indicating repair tissue properties similar to native cartilage.

Conclusions

An arthroscopic single-stage procedure using microdrilling in combination with atelocollagen gel and fibrin-glue can provide satisfactory MRI results at 1-year follow-up, with good cartilage defect filling. The T2* values in the repair tissue achieved similar values compared to normal hyaline cartilage.

     

Clinical outcome after medial patellofemoral ligament reconstruction and autologous chondrocyte implantation following recurrent patella dislocation

Purpose

Medial patellofemoral ligament (MPFL) reconstruction is a well-established treatment option in recurrent patella dislocation. The combination with associated retropatellar cartilage lesions are severe injuries and very difficult to treat. The purpose of this study was to evaluate our clinical results of MPFL reconstruction and autologous chondrocyte implantation (ACI).

Methods

Thirteen patients with recurrent patella dislocation were treated with a combination of MPFL reconstruction and ACI at our institution between 2010 and 2014. All patients had at least 2 patella dislocations. The posttraumatic cartilage lesions were grade IV according to the ICRS and were localized retropatellar in 8 cases and at the lateral femoral condyle in 2 cases. The mean defect size was 7.2 ± 3.5 cm² (3–12 cm²). Subjective and objective scores were assessed before surgery and at f/u, as well as radiologic parameters and cartilage status on magnetic resonance imaging (MRI).

Results

Ten patients (5 male, 5 female) with a mean follow-up of 2 years (minimum 1 year to 4 years) were enrolled in the study. At latest clinical follow-up, all patients had a stable patella with no signs of instability and all patients showed improved subjective and objective scores. Lysholm score increased to 74.1 ± 18.7 (48–99), KOOS score to 74.4 ± 16.9 (57–95), IKDC subjective to 63.9 ± 22.1 (34–93) and Kujala score to 73.8 ± 25.1 (50–100). The post-operative modified MOCART score for quality assessment of the ACI on MRI was an average of 13.7 ± 1.8 points (11–16), with a complete fill of the defect in 80 % of lesions.

Conclusion

Medial patellofemoral ligament reconstruction with simultaneous ACI showed good clinical results in recurrent patella dislocation with traumatic cartilage lesions grade IV. No patella re-dislocation occurred and the ACI was successful in 80 % of patients according to MRI. Subjective and objective scores improved but combined surgery is inferior to reports from the literature on MPFL reconstruction alone without cartilage damage.

Level of evidence

Therapeutic case series, Level IV.     

No negative effect on patient-reported outcome of concomitant cartilage lesions 5–9 years after ACL reconstruction

Purpose

To compare patient-reported outcome 5–9 years after anterior cruciate ligament (ACL) reconstruction in patients with and without a concomitant full-thickness [International Cartilage Repair Society (ICRS) grade 3–4] cartilage lesion.

Methods

This is a prospective follow-up of a cohort of 89 patients that were identified in the Norwegian National Knee Ligament Registry and included in the current study in 2007, consisting of 30 primary ACL-reconstructed patients with a concomitant, isolated full-thickness cartilage lesion (ICRS grade 3 and 4) and 59 matched controls without cartilage lesions (ICRS grade 1–4). At a median follow-up of 6.3 years (range 4.9–9.1) after ACL reconstruction, 74 (84 %) patients completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), which was used as the main outcome measure. Secondary outcomes included radiographic evaluation according to the Kellgren–Lawrence criteria of knee osteoarthritis (OA).

Results

At follow-up, 5–9 years after ACL reconstruction, no statistically significant differences in KOOS were detected between patients with a concomitant full-thickness cartilage lesion and patients without concomitant cartilage lesions. Radiographic knee OA of the affected knee, defined as Kellgren and Lawrence ≥2, was significantly more frequent in subjects without a concomitant cartilage lesion (p = 0.016).

Conclusion

ACL reconstruction performed in patients with an isolated concomitant full-thickness cartilage lesion restored patient-reported knee function to the same level as ACL reconstruction performed in patients without concomitant cartilage lesions, 5–9 years after surgery. This should be considered in the preoperative information given to patients with such combined injuries, in terms of the expected outcome after ACL reconstruction and in the counselling and decision-making on the subject of surgical treatment of the concomitant cartilage lesion.

Level of evidence

Prognostic; prospective cohort study, Level I.

     

Graft hypertrophy of matrix-based autologous chondrocyte implantation: a two-year follow-up study of NOVOCART 3D implantation in the knee

Purpose

Graft hypertrophy is a major complication in the treatment for localized cartilage defects with autologous chondrocyte implantation (ACI) using periosteal flap and its further development, Novocart (a matrix-based ACI procedure). The aim of the present study is to investigate individual criteria for the development of graft hypertrophy by NOVOCART 3D implantation of the knee in the post-operative course of 2 years.

Methods

Forty-one consecutive patients with 44 isolated cartilage defects of the knee were treated with NOVOCART 3D implants. Individual criteria and defect-associated criteria were collected. Follow-up MRIs were performed at 3, 6, 12 and 24 months. The NOVOCART 3D implants were measured and classified. The modified MOCART Score was used to evaluate quality and integration of the NOVOCART 3D implants in MRI.

Results

Graft hypertrophy was observed in a total of 11 patients at all post-operative time points. We were able to show that NOVOCART 3D implantation of cartilage defects after acute trauma and osteochondritis dissecans (OCD) led to a significantly increased proportion of graft hypertrophy. No other individual criteria (age, gender, BMI) or defect-associated criteria (concomitant surgery, second-line treatment, defect size, fixation technique) showed any influence on the development of graft hypertrophy. The modified MOCART Score results revealed a significant post-operative improvement within 2 years.

Conclusion

The aetiology of cartilage defects appears to have a relevant influence for the development of graft hypertrophy. Patients, who were treated with NOVOCART 3D implants after an acute event (acute trauma or OCD), are especially at risk for developing a graft hypertrophy in the post-operative course of two years.

Level of evidence

Case series, Level IV.     

Treatment of isolated chondral and osteochondral defects in the knee by autologous matrix-induced chondrogenesis (AMIC)

Purpose

The purpose of this study is to evaluate clinical and radiological outcomes of patients treated with autologous matrix-induced chondrogenesis (AMIC) for full-thickness chondral and osteochondral defects of the femoral condyles and patella.

Method

A retrospective evaluation of clinical and radiographic outcomes of patients treated with AMIC for chondral and osteochondral full-thickness cartilage defects of the knee was performed with a mean follow-up of 28.8 ± 1.5 months (range, 13–51 months).

Results

Significant improvements in clinical outcome scores (IKDC, Lysholm, Tegner, and VAS pain score) were noted. The largest improvements were seen in the osteochondral subgroup (mean age 25.9 years), whereas patients treated for chondral defects in the patellofemoral joint and on the femoral condyles improved less. Patients in all groups were generally satisfied with their results. MRI evaluation showed that tissue filling was present but generally not complete or homogenous.

Conclusions

AMIC is a safe procedure and leads to clinical improvement of symptomatic full-thickness chondral and osteochondral defects and to regenerative defect filling. The value of AMIC relative to other cartilage repair procedures and to the natural course remains undefined.

Level of evidence

Case series, Level IV.     

Matrix-induced autologous chondrocyte implantation (MACI) for chondral defects in the patellofemoral joint

Purpose

Both autologous chondrocyte implantation (ACI) and tibial tubercle transfer (TTT) have been used to treat chondral defects in the patellofemoral joint resulting in clinical improvement. Our study investigates the magnetic resonance imaging (MRI) appearance of the matrix-induced autologous chondrocyte implantation (MACI) graft at 5-year follow-up to determine if it provides a durable treatment option in patients with an average age of 42 (standard deviation 11.6).

Methods

Twenty-three patients were available for follow-up. Nine patients required realignment of the extensor mechanism with lateral release and TTT. The MRI magnetic resonance observation of cartilage repair tissue (MOCART) scoring system was used to assess the graft status. Clinical outcomes were assessed at these time periods.

Results

The mean weighted MOCART composite score improved from 2.87 at 3 months to 3.39 at 5 years, indicating an intact appearance in most grafts. Graft height measured >50 % of the adjacent native cartilage in 82 % of patients. Clinical improvement assessed by the Knee Injury and Osteoarthritis Outcome Score, SF-36 (PCS) and the 6-minute walk test was demonstrated between pre-operative scores and final 5-year follow-up. 91 % of patients would undergo MACI again. Correlation between MOCART and clinical scores were low in MACI to the patellofemoral joint. No significant difference was found in outcome between those that required realignment surgery compared with those that did not.

Conclusion

Patellofemoral MACI provides a durable graft on MRI assessment at 5 years with resultant clinical improvement. Further work is needed to determine which defect locations may benefit most from this procedure.

Level of evidence

IV.     

Cartilage extra-cellular matrix biomembrane for the enhancement of microfractured defects

Purpose

The purpose of the study was to evaluate whether the biomembrane made of cartilage extracellular matrix, designed to provide cartilage-like favourable environments as well as to prevent against washout of blood clot after microfracture, would enhance cartilage repair compared with the conventional microfracture technique.

Methods

A prospective trial was designed to compare the biomembrane cover after microfracture with conventional microfracture among patients with grade III–IV symptomatic cartilage defect in the knee joint. Patients aged 18–60 years were assigned to either the microfracture/biomembrane (n = 45) or microfracture groups (n = 19). Among them, 24 knees in the microfracture/biomembrane and 12 knees in the microfracture were followed up for 2 years. Cartilage repair was assessed with magnetic resonance imagings taken 6 months, 1 year, and 2 years postoperatively, and the clinical outcomes were also recorded.

Results

Compared with conventional microfracture, microfracture/biomembrane resulted in greater degree of cartilage repair (p = 0.043). In the intra-group analysis, while microfracture showed moderate to good degree of cartilage repair in nearly 50 % of the patients (47 % at 6 months to 50 % at 2 years; n.s.), microfracture/biomembrane maintained an equivalent degree of repair up to 2 years (88 % at 6 months to 75 % at 2 years; n.s.). The clinical outcome at 2 years also showed improved knee score and satisfaction and decreased pain in each group, but the difference between the two groups was not statistically significant.

Conclusions

Compared with conventional microfracture, biomembrane cover after microfracture yielded superior outcome in terms of the degree of cartilage repair during 2 years of follow-up. This implies that initial protection of blood clot and immature repair tissue at the microfractured defect is important for the promotion of enhanced cartilage repair, which may be obtained by the application of a biomembrane.

Level of evidence

Prospective comparative study, Level II.     

Cartilage repair in the knee with subchondral drilling augmented with a platelet-rich plasma-immersed polymer-based implant

Purpose

The aim of our study was to analyse the clinical and histological outcome after the treatment of focal cartilage defects in non-degenerative and degenerative knees with bone marrow stimulation and subsequent covering with a cell-free resorbable polyglycolic acid–hyaluronan (PGA-HA) implant immersed with autologous platelet-rich plasma (PRP).

Methods

Fifty-two patients (mean age 44 years) with focal chondral defects in radiologically confirmed non-degenerative or degenerative knees were subjected to subchondral drilling arthroscopically. Subsequently, defects were covered with the PGA-HA implant immersed with autologous PRP. At 2-year follow-up, the patients’ situation was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and compared to the pre-operative situation and 3–12-month follow-up. Biopsies (n = 4) were harvested at 18–24 months after implantation and were analysed by histology and collagen type II immune staining.

Results

At 1- and 2-year follow-up, the KOOS showed clinically meaningful and significant (p < 0.05) improvement in all subcategories compared to baseline and to 3-month follow-up. There were no differences in KOOS data obtained after 2 years compared to 1 year after the treatment. Histological analysis of the biopsy tissue showed hyaline-like to hyaline cartilage repair tissue that was rich in cells with a chondrocyte morphology, proteoglycans and type II collagen.

Conclusions

Covering of focal cartilage defects with the PGA-HA implant and PRP after bone marrow stimulation improves the patients’ situation and has the potential to regenerate hyaline-like cartilage.

Level of evidence

Case series, Level IV.     

The safety and efficacy of magnetic targeting using autologous mesenchymal stem cells for cartilage repair

Purpose

A new cell delivery system using magnetic force, termed magnetic targeting, was developed for the accumulation of locally injected cells in a lesion. The aim of this study was to assess the safety and efficacy of mesenchymal stem cell (MSC) magnetic targeting in patients with a focal articular cartilage defect in the knee.

Methods

MSC magnetic targeting for five patients was approved by the Ministry of Health Labour and Welfare of Japan. Autologous bone marrow MSCs were cultured and subsequently magnetized with ferucarbotran. The 1.0-T compact magnet was attached to a suitable position around the knee joint to allow the magnetic force to be as perpendicular to the surface of the lesion as possible. Then 1?×?10⁷ MSCs were injected into the knee joint. The magnet was maintained in the same position for 10 min after the MSC injection. The primary endpoint was the occurrence of any adverse events. The secondary endpoints were efficacy assessed by magnetic resonance imaging (MRI) T2 mapping and clinical outcomes using the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation and the Knee Injury and Osteoarthritis Outcome Score (KOOS).

Results

No serious adverse events were observed during the treatment or in the follow-up period. Swelling of the treated knee joint was observed from the day after surgery in three of the five patients. The swelling resolved within 2 weeks in two patients. MRI showed that the cartilage defect areas were almost completely filled with cartilage-like tissue. MOCART scores were significantly higher 48 weeks postoperatively than preoperatively (74.8?±?10.8 vs 27.0?±?16.8, p?=?0.042). Arthroscopy in three patients showed complete coverage of their cartilage defects. Clinical outcome scores were significantly better 48 weeks postoperatively than preoperatively for the IKDC Subjective Knee Evaluation (74.8?±?17.7 vs 46.9?±?17.7, p?=?0.014) and knee-related quality-of-life (QOL) in the KOOS (53.8?±?26.4 vs 22.5?±?30.8, p?=?0.012).

Conclusion

Magnetic targeting of MSCs was safely performed and showed complete coverage of the defects with cartilage-like tissues and significant improvement in clinical outcomes 48 weeks after treatment. The magnetic targeting of MSCs is useful as a minimally invasive treatment for cartilage repair.

Level of evidence

IV.

     

In vivo evaluation of biomechanical properties in the patellofemoral joint after matrix-associated autologous chondrocyte transplantation by means of quantitative T2 MRI

Purpose

To determine in vivo biomechanical properties of articular cartilage and cartilage repair tissue of the patella, using biochemical MRI by means of quantitative T2 mapping.

Methods

Twenty MR scans were achieved at 3T MRI, using a new 8-channel multi-function coil allowing controlled bending of the knee. Multi-echo spin-echo T2 mapping was prepared in healthy volunteers and in age- and sex-matched patients after matrix-associated autologous chondrocyte transplantation (MACT) of the patella. MRI was performed at 0° and 45° of flexion of the knee after 0 min and after 1 h. A semi-automatic region-of-interest analysis was performed for the whole patella cartilage. To allow stratification with regard to the anatomical (collagen) structure, further subregional analysis was carried out (deep–middle–superficial cartilage layer). Statistical analysis of variance was performed.

Results

During 0° flexion (decompression), full-thickness T2 values showed no significant difference between volunteers (43 ms) and patients (41 ms). Stratification was more pronounced for healthy cartilage compared to cartilage repair tissue. During 45° flexion (compression), full-thickness T2 values within volunteers were significantly increased (54 ms) compared to patients (44 ms) (p < 0.001). Again, stratification was more pronounced in volunteers compared to patients. The volunteer group showed no significant increase in T2 values measured in straight position and in bended position. There was no significant difference between the 0- and the 60-min MRI examination. T2 values in the patient group increased between the 0- and the 60-min examination. However, the increase was only significant in the superior cartilage layer of the straight position (p = 0.021).

Conclusion

During compression (at 45° flexion), healthy patellar cartilage showed a significant increase in T2-values, indicating adaptations of water content and collagen fibril orientation to mechanical load. This could not be observed within the patella cartilage after cartilage repair (MACT) of the patella, most obvious due to a lack of biomechanical adjustment.

Level of evidence

III.     

Evaluation of reproducibility of the MOCART score in patients with osteochondral lesions of the talus repaired using the autologous matrix-induced chondrogenesis technique

Purpose

To evaluate the applicability and reproducibility of magnetic resonance observation of cartilage repair tissue (MOCART) score for morphological evaluation of osteochondral lesions of the talus (OLT) repaired using autologous matrix-induced chondrogenesis (AMIC) technique.

Methods

Two radiologists (R1–R2) and two orthopaedists (O1–O2) independently reviewed 26 ankle MRIs performed on 13 patients (6 females; age: 38.9 ± 15.9, 14–63) with OLT repaired using AMIC. The MRIs were performed at 6 and 12 months from surgery. For inter/intra-observer agreement evaluation for each variable of the MOCART, we used Cohen’s kappa coefficient. Progression of MOCART between 6- and 12-month evaluation was assessed using the Wilcoxon test. The Spearman’s correlation coefficient was used to evaluate the correlation between baseline lesion size and MOCART.

Results

The inter-observer agreement between R1 and R2 ranged from poor (adhesions, k = 0.124) to almost perfect (subchondral bone, k = 0.866), between O1 and O2 from absent (effusion, k = ?0.190) to poor (surface, k = 0.172), and between R1 and O1 from absent (cartilage interface, k = ?0.324) to fair (signal intensity, k = 0.372). The intra-observer agreement of R1 ranged from poor (signal intensity, k = 0.031) to substantial (subchondral lamina, k = 0.677), while that of O1 from absent (subchondral bone, k = ?0.061) to substantial (surface, k = 0.663). There was a significant increase of MOCART between 6- and 12-month evaluation of R1 (Z = ?2.672; P = 0.008), R2 (Z = ?2.721; P = 0.007) and O1 (Z = ?3.034; P = 0.002). Conversely, the increase of MOCART of O2 was not significant (Z = ?1.665; P = 0.096). Inverse correlation between lesion size at baseline and MOCART was significant at 12-month evaluation (?0.726; P = 0.005).

Conclusion

MRI has an important role in the follow-up of surgical repaired OLT, but MOCART score does not seem to be sufficiently reproducible to be applied for this purpose.

     

Use of innovative biomimetic scaffold in the treatment for large osteochondral lesions of the knee

Purpose

Large osteochondral defects involve two different tissues characterized by different intrinsic healing capacity. Different techniques have been proposed to treat these lesions with results still under discussion. The aim of the study is to evaluate the clinical outcome of 19 patients treated with a type I collagen–hydroxyapatite nanostructural biomimetic osteochondral scaffold at minimum follow-up of 2 years.

Methods

Twenty lesions, 19 patients were treated with this scaffold implantation. The lesions size went from 4 to 8 cm² (mean size 5.2 ± 1.6 cm²). All patients were clinically evaluated using the International Repair Cartilage Society score, the Tegner Score and EQ-VAS. MRI was performed at 12 and 24 months after surgery and then every 12 months and evaluated with magnetic resonance observation of cartilage repair tissue scoring scale.

Results

The IKDC subjective score improved from a mean score of 35.7 ± 6.3 at the baseline evaluation to 67.7 ± 13.4 at 12-month follow-up (p < 0.0005). A further improvement was documented from 12 to 24 months (mean score of 72.9 ± 12.4 at 24 months) (p < 0.0005). The IKDC objective score confirmed the results. The Tegner activity score improvement was statistically significant (p < 0.0005). The EQ-VAS showed a significant improvement from 3.15 ± 1.09 to 7.35 ± 1.14 (p < 0.0005) at 2-year follow-up. The lesion’ site seems to influence the results showing a better outcome in the patients affected in the medial femoral condyle.

Conclusions

The use of the MaioRegen scaffold is a good procedure for the treatment for large osteochondral defects where other classic techniques are difficult to apply. It is an open one-step surgery with promising stable results at medium follow-up.

Level of evidence

IV.     

Alignment does not influence cartilage T2 in asymptomatic knee joints

Purpose

To investigate whether the static knee alignment affects articular cartilage ultrastructures when measured using T2 relaxation among asymptomatic subjects.

Methods

Both knee joints (n = 96) of 48 asymptomatic volunteers (26 females, 22 males; 25.4 ± 1.7 years; no history of major knee trauma or surgery) were evaluated clinically (Lysholm, Tegner) and by MRI (hip–knee–ankle angle, standard knee protocol, T2 mapping). Group (n = 4) division was as follows: neutral (<1° varus/valgus), mild varus (2°–4° varus), severe varus (>4° varus) and valgus (2°–4° valgus) deformity with n = 12 subjects/group; n = 24 knees/group. Regions of interest (ROI) for T2 assessment were placed within full-thickness cartilage across the whole joint surface and were divided respecting compartmental as well as functional joint anatomy.

Results

Leg alignment was 0.7° ± 0.5° varus among neutral, 3.0° ± 0.6° varus among mild varus, 5.0° ± 1.1° varus among severe varus and 2.5° ± 0.7° valgus among valgus group subjects and thus significantly different. No differences between the groups emerged from clinical measures. No morphological pathology was detected in any knee joint. Global T2 values (42.3 ± 2.3; 37.7–47.9 ms) of ROIs placed within every knee joint per subject were not different between alignment groups or between genders, respectively.

Conclusion

Static frontal plane leg malalignment does not affect cartilage ultrastructure among young, asymptomatic individuals as measured by T2 quantitative imaging.

Level of evidence

Cross-sectional study, Level II-III.     

The use of fibrin matrix-mixed gel-type autologous chondrocyte implantation in the treatment for osteochondral lesions of the talus

Purpose

This study assessed the clinical results and second-look arthroscopy after fibrin matrix-mixed gel-type autologous chondrocyte implantation to treat osteochondral lesions of the talus.

Methods

Chondrocytes were harvested from the cuboid surface of the calcaneus in 38 patients and cultured, and gel-type autologous chondrocyte implantation was performed with or without medial malleolar osteotomy. Preoperative American orthopedic foot and ankle society ankle-hind foot scores, visual analogue score, Hannover scoring system and subjective satisfaction were investigated, and the comparison of arthroscopic results (36/38, 94.7 %) and MRI investigation of chondral recovery was performed. Direct tenderness and relationship to the active daily life of the donor site was evaluated.

Results

The preoperative mean ankle–hind foot scores (71 ± 14) and Hannover scoring system (65 ± 10) had increased to 91 ± 12 and 93 ± 14, respectively, at 24-month follow-up (p < 0.0001), and the preoperative visual analogue score of 58 mm had decreased to 21 mm (p < 0.0001). Regarding subjective satisfaction, 34 cases (89.5 %) reported excellent, good or fair. Chondral regeneration was analysed by second-look arthroscopy and MRI. Complications included one non-union and two delayed-unions of the osteotomy sites, and 9 ankles (9/31, 29.0 %) sustained damaged medial malleolar cartilage due to osteotomy. Marked symptoms at the biopsy site did not adversely affect the patient’s active daily life.

Conclusions

Fibrin matrix-mixed gel-type autologous chondrocyte implantation using the cuboid surface of the calcaneus as a donor can be used for treating osteochondral lesions of the talus.

Level of evidence

Therapeutic study, prospective case series, Level IV.     

Early resumption of physical activities leads to inferior clinical outcomes after matrix-based autologous chondrocyte implantation in the knee

Purpose

Matrix-based autologous chondrocyte implantation is a well-established operation procedure for full cartilage defects. When to resume physical activity after matrix-based autologous chondrocyte implantation is controversial. Our hypothesis was that early resumption of physical activity leads to a worse clinical outcome after matrix-based autologous chondrocyte implantation in the knee two years post-operatively. Physical activity is defined as any kind of impact sport.

Methods

Forty-four patients with cartilage defects of the knee were treated with matrix-based autologous chondrocyte implantation (Novocart^®3D). All patients were assessed preoperatively and after a period of 24 months with the University of California Los Angeles (UCLA) Activity score. The return to physical activities or sports after matrix-based autologous chondrocyte implantation was documented. Patients were evaluated using the International Knee Documentation Committee Knee Examination Form and visual analogue scale for pain after 6, 12 and 24 months.

Results

Fifty-five percent showed an unchanged level of physical activity in the UCLA Activity score post-operatively. About 35 % showed a lower level and 10 % a higher level of physical activity. The average return to physical activities or sports after matrix-based autologous chondrocyte implantation procedure was 10.2 months. Patients with a later return of sports after 12 months showed significantly better clinical results after two years. In particular, patients who started practicing impact sport after 12 months post-operatively showed significantly better results.

Conclusion

Resuming physical activity including impact sports without waiting at least 12 months after the operation leads to inferior outcomes up to 24 months after matrix-based autologous chondrocyte implantation.

Level of evidence

Level IV.     

Arthroscopic autologous chondrocyte implantation in the ankle joint

Purpose

Autologous chondrocyte implantation (ACI) is an established procedure in the ankle providing satisfactory results. The development of a completely arthroscopic ACI procedure in the ankle joint made the technique easier and reduced the morbidity. The purpose of this investigation was to report the clinical results of a series of patients who underwent arthroscopic ACI of the talus at a mean of 7 ± 1.2-year follow-up.

Methods

Forty-six patients (mean age 31.4 ± 7.6) affected by osteochondral lesions of the talar dome (OLT) received arthroscopic ACI between 2001 and 2006. Patients were clinically evaluated using AOFAS score pre-operatively and at 12, 36 months and at final follow-up of 87.2 ± 14.5 months.

Results

The mean pre-operative AOFAS score was 57.2 ± 14.3. At the 12-month follow-up, the mean AOFAS score was 86.8 ± 13.4 (p = 0.0005); at 36 months after surgery, the mean score was 89.5 ± 13.4 (p = 0.0005); whereas at final follow-up of 87.2 ± 14.5 months it was 92.0 ± 11.2 (p = 0.0005). There were three failures. Histological and immunohistochemical evaluations of specimens harvested from failed implants generally showed several aspects of a fibro-cartilaginous tissue associated with some aspects of cartilage tissue remodelling as indicated by the presence of type II collagen expression.

Conclusion

This study confirmed the ability of arthroscopic ACI to repair osteochondral lesions in the ankle joint with satisfactory clinical results after mid-term follow-up.

Level of evidence

IV, retrospective case series.