Arthroscopic autologous osteochondral grafting for cartilage defects of the knee: prospective study results at a minimum 7-year follow-up

Influence of intra-articular administration of trichostatin a on autologous osteochondral transplantation in a rabbit model

Autologous osteochondral transplantation (AOT) is a method for articular cartilage repair. However, several disadvantages of this method have been reported, such as transplanted cartilage degeneration and the lack of a connection between the grafted and adjacent cartilage tissues. To evaluate the effect of intra-articular administration of trichostatin A (TSA) on AOT, we conducted a case control study in a rabbit model. International Cartilage Repair Society (ICRS) macroscopic scores, the modified O'Driscoll histology scores, and real-time PCR were utilized to evaluate the results. At 4 weeks, both macroscopic and histological assessments showed that there was no significant difference between the TSA and control groups. However, the mean macroscopic and histological scores for the TSA-treated group were significantly higher than the scores for the control group at 12 weeks. TSA was shown to directly reduce collagen type II (COL2), aggrecan, matrix metalloproteinase (MMP), and a disintegrin and metalloproteinase domain with thrombospondin motifs 5 (ADAMTS-5) expression and to simultaneously repress the upregulation of MMP-3, MMP-9, and MMP-13 levels induced by interleukin 1β (IL-1β) in chondrocytes. In conclusion, TSA protects AOT grafts from degeneration, which may provide a benefit in the repair of articular cartilage injury.

Arthroscopic mosaicplasty: long-term outcome and joint degeneration progression

BACKGROUND

This study aims to document the long-term results in a group of patients treated with arthroscopic mosaicplasty for knee cartilage lesions, both in terms of clinical outcome and joint degeneration progression, evaluated by radiographs.

METHODS

26 patients (19 men and 7 women, mean age 29 years, mean BMI 23) treated arthroscopically with mosaicplasty for cartilage defects of the femoral condyles (mean/median/mode size 1.9 standard deviation, SD 0.6 cm(2)) were prospectively evaluated at 12 years follow-up. The clinical outcome was analyzed with IKDC and Tegner scores. Range of motion, transpatellar and suprapatellar circumferences were also measured. Radiographs with weight-bearing antero-posterior and Rosenberg projections were used for radiological evaluation in 18 patients, applying both Kellgren-Lawrence score and a direct joint line measurement to assess osteoarthritis.

RESULTS

A significant improvement in all clinical scores was obtained from the basal evaluation to the 12-year follow-up (IKDC subjective score from 36.8 standard deviation, SD 13.0 to 77.3 standard deviation, SD 20.6, P<0.0005; Tegner score from 2.9 standard deviation, SD 1.3 to 5.2 standard deviation, SD 2.5, P<0.0005), and better results in patients with a higher pre-injury activity level and those requiring fewer plugs. The radiographic evaluation showed significantly poorer Kellgren-Lawrence scores and a reduction of the joint line in the treated compartments. Knees with 3-4 plugs presented a significantly higher joint degeneration level with respect to those implanted with 1-2 plugs.

CONCLUSIONS

Mosaicplasty is an effective surgical option for small lesions of the femoral condyles. Although joint degeneration progression was present at 12 years, this did not affect significantly the clinical outcome which was satisfactory at long-term follow-up.

Osteochondral allograft transplant to the medial femoral condyle using a medial or lateral femoral condyle allograft: is there a difference in graft sources?

BACKGROUND

Osteochondral allograft (OCA) transplantation is an effective treatment for defects in the medial femoral condyle (MFC), but the procedure is limited by a shortage of grafts. Lateral femoral condyles (LFCs) differ in geometry from MFCs but may be a suitable graft source. The difference between articular surface locations of the knee can be evaluated with micro-computed tomography imaging and 3-dimensional image analysis.

HYPOTHESIS

LFC OCAs inserted into MFC lesions can provide a cartilage surface match comparable with those provided by MFC allografts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty MFCs and 10 LFCs were divided into 3 groups: 10 MFC recipients (MFCr), 10 MFC donors (MFCd), and 10 LFC donors (LFCd). A 20-mm defect was created in the weightbearing portion of the MFCr. Two grafts, 1 MFCd and 1 LFCd, were implanted sequentially into each MFCr. Micro-computed tomography (μCT) images of the MFCr were acquired and analyzed to compare the topography of the original recipient site with the MFCd- and LFCd-repaired sites. Three-dimensional transformations were defined to register the defect site in the 3 scans of each MFCr. Vertical deviations from each voxel of the graft cartilage surface, relative to the intact recipient cartilage surface, were calculated and assessed as root mean square deviation and percentage graft area that was proud, sunk, and within the "acceptable" distance (±1.00 mm). The effect of repair (with MFC vs with LFC) on each of the surface match parameters is presented as mean ± SD and was assessed by t test: height deviation over area (root mean square, mm), graft area acceptable (%), area unacceptably proud (%), area unacceptably sunk (%), step-off height over circumference (root mean square, mm), graft circumference acceptable (%), circumference unacceptably proud (%), and circumference unacceptably sunk (%). Percentage data were arcsin transformed before statistical testing. An alpha level of 0.05 was used to conclude if variations were statistically significant.

RESULTS

MFCr defects were filled with both orthotopic MFCd and nonorthotopic LFCd. Registered μCT images of the MFCr illustrate the cartilage surface contour in the sagittal and coronal planes, in the original intact condyle, as well as after OCA repairs. Specimen-specific surface color maps for the MFCr after implant of the MFCd and after implant of LFCd were generally similar, with some deviation near the edges. On average, the MFCr site exhibited a typical contour, and the MFCd and LFCd were slightly elevated. Both types of OCA-MFCd and LFCd-matched well, showing overall height deviations of 0.63 mm for area and 0.47 mm for step-off, with no significant difference between MFCd and LFCd (P = .92 and .57, respectively) and acceptable deviation based on area (87.6% overall) and step-off (96.7% overall), with no significant difference between MFCd and LFCd (P = .87 and .22, respectively). A small portion of the implant was proud (12.1% of area and 2.6% of circumference step-off height), with no significant difference between MFCd and LFCd (P = .26 and .27, respectively). A very small portion of the implant area and edge was sunk (0.3% of area and 0.6% of circumference), with no significant difference between MFCd and LFCd (P = .29 and .86, respectively).

CONCLUSION/CLINICAL RELEVANCE

The achievement of excellent OCA surface match with an MFCd or LFCd graft into the common MFCr site suggests that nonorthotopic LFC OCAs are acceptable graft options for MFC defects.

Single-plug autologous osteochondral transplantation: results at minimum 16 years' follow-up

Different techniques have been proposed for the treatment of cartilage defects. Among the currently available options, autologous single-plug osteochondral transplantation is one of the few to be applied to address small and medium lesions. The goal of the current study was to document the long-term clinical outcome of a cohort of patients treated by this surgical strategy, which consists of harvesting a single osteochondral plug from a less weight bearing area of the knee and implanting it on the defect site by press-fit technique. Fifteen patients were enrolled. Age at surgery was 30.2±15.3 years, and body mass index was 22.5±3.0 kg/m(2). The inclusion criteria were clinical symptoms, such as knee pain or swelling, and grade III to IV chondral and osteochondral knee lesions. Patients were prospectively evaluated up to a mean of 17.5±3.5 years of follow-up by using Lysholm, International Knee Documentation Committee (IKDC) subjective, and Tegner scores. A significant improvement was noted in all clinical scores. In particular, the IKDC subjective score increased from 34.5±23.6 to 66.3±26.4 (P=.001). The Lysholm score showed a similar trend. From a baseline value of 47.8±29.5, the score increased to 79.8±24.6 at the last evaluation (P=.001). A significant increase in Tegner score was observed at the 2-year evaluation, with stable results up to the last follow-up. Four failures were reported, which in 3 cases occurred at mid- to long-term follow-up, confirming that this technique can be considered a suitable option for the treatment of small and medium chondral and osteochondral lesions in young patients.

Weight-bearing compared with non-weight-bearing following osteochondral autograft transfer for small defects in weight-bearing areas in the femoral articular cartilage of the knee

BACKGROUND

Patients are routinely kept non-weight-bearing for four to eight weeks following osteochondral autograft transfer to repair cartilage defects of the medial and/or lateral femoral condyle. Therefore, the objective of this novel study was to investigate whether postoperative weight-bearing restrictions affect the outcomes of cartilage repair when an osteochondral autograft transfer system is used to repair small defects in weight-bearing areas of femoral articular cartilage.

METHODS

This a retrospective comparative study. Following review of the charts on 567 consecutive arthroscopic osteochondral autograft transfers, three homogeneous groups of patients with consecutive cases were identified: group A, cases of patients who were non-weight-bearing following the procedure (n = 68); group B, cases of those who were non-weight-bearing following the procedure with concomitant anterior cruciate ligament reconstruction (n = 29); and group C, cases of those who were weight-bearing as tolerated following the procedure (n = 437). The cases of patients whose knees underwent second-look (repeat) arthroscopy were stratified into two subgroups: non-weight-bearing (n = 20) and weight-bearing as tolerated (n = 42). Graft position and manifestation of a repair-adjacent defect (Outerbridge grade-III or IV cartilage defect that develops adjacent to the original osteochondral autograft transfer repair) were assessed during second-look arthroscopy. Cartilage repair was retrospectively assessed from second-look arthroscopy pictures by a blinded, independent orthopaedic surgeon with use of the International Cartilage Repair Society macroscopic cartilage-repair assessment tool. Postoperative complication rates were compared among the three primary groups.

RESULTS

The mean grafted area was 0.72 cm(2) (range, 0.16 to 1.45 cm(2)) and 0.73 cm(2) (range, 0.16 to 1.80 cm(2)) for the non-weight-bearing and weight-bearing-as-tolerated second-look subgroups, respectively. The mean International Cartilage Repair Society score was 11.12 and 11.25 points (near-normal cartilage) for the non-weight-bearing and weight-bearing-as-tolerated subgroups (p = 0.71) at a mean follow-up of 42.7 and 33.0 months, respectively. There was no significant difference in the duration of follow-up (p = 0.58), repair-adjacent defect prevalence (p = 0.94), or graft position (p = 0.99) between the two subgroups. Weight-bearing-as-tolerated patients (group C) experienced significantly fewer deep vein thrombosis and arthrofibrosis complications compared with non-weight-bearing patients (groups A and B) (p < 0.001).

CONCLUSIONS

Postoperative weight-bearing restrictions did not affect mid-term cartilage repair outcomes in patients who underwent second-look arthroscopy when an osteochondral autograft transfer system was used to repair small defects in weight-bearing areas of cartilage of the medial and/or lateral femoral condyle.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Correlation Between Clinical and Radiological Outcomes After Matrix-Induced Autologous Chondrocyte Implantation in the Femoral Condyles

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) is an established technique for the repair of knee chondral defects, although the correlation between clinical and radiological outcomes after surgery is poorly understood.

PURPOSE

To determine the correlation between clinical and radiological outcomes throughout the postoperative timeline to 5 years after MACI.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

This retrospective study was undertaken in 83 patients (53 male, 30 female) with complete clinical and radiological follow-up at 1, 2, and 5 years after MACI. The mean age of patients was 38.9 years (range, 13-62 years), with a mean body mass index (BMI) of 26.6 kg/m(2) (range, 16.8-34.8 kg/m(2)), mean defect size of 3.3 cm(2) (range, 1-9 cm(2)), and mean preoperative duration of symptoms of 9.2 years (range, 1-46 years). Patients indicated for MACI in this follow-up were 13 to 65 years of age, although they were excluded if they had a BMI >35 kg/m(2), had undergone prior extensive meniscectomy, or had ongoing progressive inflammatory arthritis. Patients were assessed clinically using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Magnetic resonance imaging (MRI) was used to evaluate the graft using a 1.5-T or 3-T clinical scanner; the MRI assessment included 8 parameters of graft repair (infill, signal intensity, border integration, surface contour, structure, subchondral lamina, subchondral bone, and effusion) based on the magnetic resonance observation of cartilage repair tissue (MOCART) score as well as an MRI composite score. The degree of an association between the MRI parameters and the KOOS subscales at each postoperative time point was assessed with the Spearman correlation coefficient (SCC), and significance was determined at P < .05. Ethics approval was obtained from the appropriate hospital and university Human Research Ethics Committees, and informed consent was gathered from all patients.

RESULTS

The only MRI parameter displaying consistent evidence of an association with the KOOS subscales was effusion, with a pattern of increasing strength of correlations over time and statistically significant associations at 5 years with KOOS-Pain (SCC, 0.25; P = .020), KOOS-Activities of Daily Living (SCC, 0.26; P = .018), and KOOS-Sport (SCC, 0.32; P = .003). Apart from a significant correlation between subchondral lamina and KOOS-Sport at 1 year (SCC, 0.27; P = .016), no further significant findings were observed.

CONCLUSION

Apart from some consistent evidence of an association between the KOOS and effusion, this analysis demonstrated a limited correlative capacity between clinical and radiological outcomes up to 5 years after surgery.

Arthroscopic debridement of unicompartmental arthritis: fact or fiction?

Patients with recurrent or mechanical symptoms of unicompartmental knee arthritis that have failed conservative management are candidates for surgical intervention. Surgical options include debridement, lavage, chondroplasty, bone marrow-stimulating techniques, chondrocyte transfer, and chondrocyte implantation. These techniques have been well studied but it is still unclear which technique is superior. Various factors need to be accounted for when choosing the proper technique; among the factors discussed are the patient's age and the size of the articular cartilage defect.

Osteochondral transplantation for the treatment of osteochondral defects at the talus with the Diamond twin system(®) and graft harvesting from the posterior femoral condyles

BACKGROUND

The aim of this study is to analyze clinical results after osteochondral cylinder transplantation for osteochondral defects at the medial or lateral talar dome using the Diamond twin system (Karl Storz). We hypothesize that grafts harvesting from the posterior femoral condyles are associated with less donor site morbidity than reported by previous studies.

METHODS

We have surgically treated 20 patients with an osteochondral defect of the talus by osteochondral transplantation with the Diamond twin system via an osteotomy of the ankle. The osteochondral cylinders were harvested from the posterior aspects of the femoral condyles of the ipsilateral knee. The defects at donor site were filled with a bone substitute of tricalcium phosphate (Synthricer, Karl Storz). The mean age was 25.4 years. After a mean time of 12.6 months, the screws at the medial malleolus were removed and an arthroscopy was performed. The functional outcome was evaluated with the visual analog scale for pain at walking, running, stair climbing, quality of life at the time of implant removal and at a mean follow-up of 25.8 months. Activity was assessed with the Tegner scale. Knee function was evaluated with the Lysholm score.

RESULTS

In one case, the osteochondral cylinder did not heal and an osteochondral fragment was removed arthroscopically. In all other cases, the osteochondral cylinder was stable with surrounding cartilage. The average ICRS Cartilage Repair Assessment was 10.1 points (±1.3). All malleolar osteotomies healed radiologically. In 15 patients, a synovectomy and local debridement of the ankle were performed at second-look arthroscopy. Ankle pain at walking, running and stair climbing as measured by a visual analog scale (10-0) decreased significantly from preoperatively to the first follow-up (mean 12.6 months) and to the second follow-up (mean 25.8 months). The ankle-related quality of life increased significantly from preoperatively to postoperatively. There was no significant change in the Lysholm score. The activity measured with the Tegner activity scale increased significantly from preoperatively to the last follow-up, but only two out of nine patients continued pivoting sports.

CONCLUSIONS

Autologous osteochondral grafting with the Diamond twin system is a reliable treatment option for symptomatic osteochondral defects of the talus. After 1 year, the majority of patients had still some complaints. However, after screw removal and second-look arthroscopy, the pain and ankle-related quality of life further improved.

CLINICAL RELEVANCE

The donor site morbidity after graft harvesting from the posterior aspects of the femoral condyles is lower than previously reported.

Whole joint MRI assessment of surgical cartilage repair of the knee: cartilage repair osteoarthritis knee score (CROAKS)

OBJECTIVE

To develop a magnetic resonance imaging (MRI) scoring system for follow-up of knee cartilage repair procedures integrating assessment of the repair site and the whole joint called Cartilage Repair OsteoArthritis Knee Score (CROAKS), and to assess its reliability.

DESIGN

MRI examinations of 20 patients that had undergone matrix-associated autologous chondrocyte transplantation (MACT) of the knee 12 months before were semi-quantitatively assessed for the repair site using features of the magnetic resonance observation of cartilage repair tissue (MOCART) system and for the whole joint based on experiences with the MRI Osteoarthritis Knee Score (MOAKS) instrument. Intra- and inter-observer reliability was calculated using weighted (w) kappa statistics for plates (medial/lateral tibia, medial/lateral femur, trochlea, patella), compartments (medial tibio-femoral, lateral tibio-femoral, patello-femoral) and the whole joint. For certain features with low prevalence the overall percent agreement was calculated in addition.

RESULTS

For cartilage, reliability on a plate level ranged between 0.48 (lateral femur) and 1.00 (medial femur). BML assessment showed comparable results ranging on a plate level between 0.46 and 1.00 with overall percent agreement between 83.3% and 100%. Meniscal morphology assessment ranged between 0.62 and 0.94. For repair site assessment reliability ranged from 0.41 (signal intensity inter-observer) to 1.00 (several features). Overall percent agreement was above 80% for 17 of 22 features assessed (intra- and inter-observer results combined).

CONCLUSIONS

Combined scoring of the repair site and whole joint assessment for common osteoarthritis features using CROAKS, which is based on experience with two established semi-quantitative scoring tools, is feasible and may be performed with good to excellent reliability.

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.

Autologous osteochondral transplantation for treating patellar chondral injuries: evaluation, treatment, and outcomes of a two-year follow-up study

BACKGROUND

The patella is the largest human sesamoid bone and often sustains chondral injury. There is no consensus on how to treat a full-thickness, symptomatic articular cartilage injury of the patella. We analyzed the clinical and functional outcomes of patients with symptomatic full-thickness patellar chondral lesions treated with autologous osteochondral transplantation and evaluated osteochondral autograft bone-plug integration through magnetic resonance imaging.

METHODS

In this prospective study, thirty-three patients with a symptomatic full-thickness patellar chondral injury surgically treated with autologous osteochondral transplantation were evaluated before and after surgical treatment with a minimum two-year follow-up using the Lysholm, Kujala, and Fulkerson questionnaires and the Short Form-36 health survey score. Magnetic resonance images were made at six and twelve months postoperatively and studies were performed to analyze the osteochondral autograft bone-plug integration.

RESULTS

All thirty-three patients showed a significant improvement in functional scores two years after surgery. The average Lysholm scores were 57.27 points preoperatively and 80.76 points at two years postoperatively, the average Kujala scores were 54.76 points preoperatively and 75.18 points at two years postoperatively, and the Fulkerson average scores were 54.24 points preoperatively and 80.42 points at two years postoperatively. The Short Form-36 life quality score improved significantly. Two years after surgery, all magnetic resonance images showed full bone-plug integration into the patella.

CONCLUSIONS

Autologous osteochondral transplantation is a successful technique to surgically treat symptomatic full-thickness patellar articular cartilage injuries smaller than 2.5 cm in diameter. Patients had a significant improvement in clinical scores. Bone-plug integration and surface alignment were demonstrated in all patients two years after surgery.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Autologous osteochondral transplantation for the treatment of knee lesions: results and limitations at two years' follow-up

PURPOSE

Focal chondral and osteochondral knee lesions are a common condition, particularly hard to treat, and often involve young active patients with high expectations in terms of symptomatic relief and return to sports. Autologous osteochondral transplantation allows the defect area to be restored with hyaline cartilage. The aim of this study is to analyse whether it represents a safe and effective treatment option for small-medium-sized knee chondral and osteochondral lesions in a young and active population.

METHODS

Thirty-one patients (18 men, 13 women; mean age 32 ± ten; mean BMI 24 ± 3) affected by focal knee chondral and osteochondral lesions were enrolled and treated with autologous osteochondral transplantation. They were prospectively followed-up for 24 months with the IKDC-subjective, IKDC-objective, and Tegner scores. Adverse events and failures were also reported, as well as the Bandi score to detect symptoms from the donor area.

RESULTS

A significant increase was reported in all the clinical scores adopted. In particular, the IKDC-subjective score increased from a basal value of 40.3 ± 16.2 to 62.6 ± 18.0 at the 12 months' evaluation, with a further significant increase up to 71.6 ± 20.5 at the final 24 months' follow-up (p < 0.0005). A positive trend was also found by analysing the IKDC-objective score. The Tegner score revealed a significant improvement from a basal value of 2.2 ± 1.8 to 3.7 ± 1.5 at the final evaluation (p = 0.003), although it was not possible to regain the same pre-injury sports activity level of 5.0 ± 2.2. Two failures were reported. The Bandi score revealed patients complaining of mild and moderate symptoms, not correlated to the lesion size. The presence of symptoms ascribable to the donor area was significantly correlated with a lower clinical outcome.

CONCLUSIONS

Autologous osteochondral transplantation proved to be, at short-term evaluation, a suitable option to treat small-medium sized chondral and osteochondral lesions. However, clinical improvement is slow and a significant percentage of patients develop symptoms attributable to the donor area, thus reducing the overall benefit of this procedure.

Cell-laden biphasic scaffolds with anisotropic structure for the regeneration of osteochondral tissue

Sufficient treatment of chondral and osteochondral defects to restore function of the respective tissue remains challenging in regenerative medicine. Biphasic scaffolds that mimic properties of bone and cartilage are appropriate to regenerate both tissues at the same time. The present study describes the development of biphasic, but monolithic scaffolds based on alginate, which are suitable for embedding of living cells in the chondral part. Scaffolds are fabricated under sterile and cell-compatible conditions according to the principle of diffusion-controlled, directed ionotropic gelation, which leads to the formation of channel-like, parallel aligned pores, running through the whole length of the biphasic constructs. The synthesis process leads to an anisotropic structure, as it is found in many natural tissues. The two different layers of the scaffolds are characterized by different microstructure and mechanical properties which provide a suitable environment for cells to form the respective tissue. Human chondrocytes and human mesenchymal stem cells were embedded within the chondral layer of the biphasic scaffolds during hydrogel formation and their chondrogenic (re)differentiation was successfully induced. Whereas viability of non-induced human mesenchymal stem cells decreased during culture, cell viability of human chondrocytes and chondrogenically induced human mesenchymal stem cells remained high within the scaffolds over the whole culture period of 3 weeks, demonstrating successful fabrication of cell-laden centimetre-scaled constructs for potential application in regenerative treatment of osteochondral defects. Copyright © 2014 John Wiley & Sons, Ltd.

Bioglass®/chitosan-polycaprolactone bilayered composite scaffolds intended for osteochondral tissue engineering

Polymer-coated 45S5 Bioglass(®) (BG)/chitosan-polycaprolactone (BG/CS-PCL) bilayered composite scaffolds were prepared via foam replication and freeze-drying techniques for application in osteochondral tissue engineering. The CS-PCL coated and uncoated BG scaffolds were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The mechanical properties of the coated scaffolds were significantly improved in comparison to uncoated scaffolds. The bioactivity and biodegradation behavior of scaffolds were studied in simulated body fluid (SBF) for up to 28 days. The interface between the BG scaffold and the polymer coating layer was observed by SEM and a suitable interpenetration of the polymer into the scaffold struts was found. The effects of coated and uncoated BG scaffolds on MG-63 osteoblast-like cells were evaluated by cell viability, adhesion and proliferation.

The John Insall Award: A minimum 10-year outcome study of autologous chondrocyte implantation

BACKGROUND

Autologous chondrocyte implantation (ACI) has demonstrated good and excellent results in over 75% of patients up to 10 years after surgery. Reports of longer-term outcomes, however, remain limited.

QUESTIONS/PURPOSES

The purposes of this study were to describe the (1) survivorship of ACI grafts; (2) the long-term functional outcomes using validated scoring tools after ACI; and (3) to provide an analysis of potential predictors for failure.

METHODS

Two hundred ten patients treated with ACI were followed for more than 10 years. Indications for the procedure included symptomatic cartilage defects in all compartments of the knee unresponsive to nonoperative measures. Mean age at surgery was 36 ± 9 years; mean defect size measured 8.4 ± 5.5 cm(2). Outcome scores were prospectively collected pre- and postoperatively at the last followup.

RESULTS

At a mean of 12 ± 2 years followup, 53 of 210 patients (25%) had at least one failed ACI graft. Nineteen of these patients went on to arthroplasty, 27 patients were salvaged with revision cartilage repair, and seven patients declined further treatment; three patients were lost to followup. The modified Cincinnati increased from 3.9 ± 1.5 to 6.4 ± 1.5, WOMAC improved from 39 ± 21 to 23 ± 16, Knee Society Score (KSS) knee score rose from 54 ± 18 to 79 ± 19, and KSS function from 65 ± 23 to 78 ± 17 (all p < 0.0001). The Physical Component of the SF-36 score increased from 33 ± 14 to 49 ± 18, whereas the Mental Component improved from 46 ± 14 to 52 ± 15 (both p < 0.001). Survivorship was higher in patients with complex versus salvage-type lesions (p = 0.03) with primary ACI versus ACI after prior marrow stimulation (p = 0.004) and with concomitant high tibial osteotomy (HTO) versus no HTO (p = 0.01).

CONCLUSIONS

ACI provided durable outcomes with a survivorship of 71% at 10 years and improved function in 75% of patients with symptomatic cartilage defects of the knee at a minimum of 10 years after surgery. A history of prior marrow stimulation as well as the treatment of very large defects was associated with an increased risk of failure.

Joint-preserving surgical options for management of chondral injuries of the hip

Management of injuries to the articular cartilage is complex and challenging; it becomes especially problematic in weight-bearing joints such as the hip. Several causes of articular cartilage damage have been described, including trauma, labral tears, and femoroacetabular impingement, among others. Because articular cartilage has little capacity for healing, nonsurgical management options are limited. Surgical options include total hip arthroplasty, microfracture, articular cartilage repair, autologous chondrocyte implantation, mosaicplasty, and osteochondral allograft transplantation. Advances in hip arthroscopy have broadened the spectrum of tools available for diagnosis and management of chondral damage. However, the literature is still not sufficiently robust to draw firm conclusions regarding best practices for chondral defects. Additional research is needed to expand our knowledge of and develop guidelines for management of chondral injuries of the hip.

Early evaluation and value-based pricing of regenerative medicine technologies

Since the first pioneering scientists explored the potential of using human cells for therapeutic purposes the branch of regenerative medicine has evolved to become a mature industry. The focus has switched from ‘what can be done‘ to ‘what can be commercialized‘. Timely health economic evaluation supports successful marketing by establishing the value of a product from a healthcare system perspective. This article reports results from a research project on early health economic evaluation in collaboration with developers, clinicians and manufacturers. We present an approach to determine an early value-based price for a new treatment of cartilage defects of the knee from the area of regenerative medicine. Examples of using evaluation results for the purpose of business planning, market entry, preparing the coverage decision and managed entry are discussed.

Osteochondral autologous transfer combined with valgus high tibial osteotomy: long-term results and survivorship analysis

BACKGROUND

Deep osteochondral defects of the medial femoral condyle in young and active patients are a serious condition that might lead to early osteoarthritis of the knee joint. Concomitant varus malalignment most likely promotes this process because of overloading of the medial compartment. Osteochondral autologous transfer (OAT) combined with valgus high tibial osteotomy (HTO) might therefore be a comprehensive solution to preserve long-term knee function in these patients.

PURPOSE

To evaluate clinical long-term results and analyze survival rates (conversion to knee joint arthroplasty) after combined OAT and valgus HTO in young and active patients with symptomatic osteochondral defects of the medial femoral condyle and concomitant varus malalignment.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 1998 and 2008, combined OAT and valgus HTO was performed in 86 patients with deep osteochondral defects of the medial femoral condyle and concomitant varus malalignment >2°; 74 patients (86%) were available for follow-up evaluation. The mean age of patients was 38 years, and the mean follow-up time was 7.5 years. Knee function was assessed using the Lysholm score, and pain intensity was measured using the visual analog scale (VAS). The survival rates of this combined procedure were evaluated. Failure was defined as conversion to knee joint arthroplasty during the follow-up period.

RESULTS

Adjusted to follow-up time, the Lysholm score showed a mean increase of 33 points (95% CI, 27.1-39.4; P < .001) from 40 to 73, representing a significant improvement compared with preoperatively. The VAS score decreased by a mean of 4.8 points (95% CI, 4.1-5.5; P < .001) from 7.5 to 2.7, and 93% of the patients were satisfied with the results of the operative procedure. Mean survival rates were 95.2% ± 2.7% at 5 years, 93.2% ± 3.3% at 7 years, and 90.1% ± 4.4% at 8.5 years after surgery.

CONCLUSION

Combined OAT and valgus HTO is an option to successfully treat patients with deep osteochondral defects of the medial femoral condyle and concomitant varus malalignment. Significantly improved knee function, decreased pain intensity, and a high survivorship rate can be expected up to 8.5 years postoperatively.

Return to an athletic lifestyle after osteochondral allograft transplantation of the knee

BACKGROUND

Osteochondral allograft transplantation (OATS) is a treatment option that provides the ability to restore large areas of hyaline cartilage anatomy and structure without donor site morbidity and promising results have been reported in returning patients to some previous activities. However, no study has reported on the durability of return to activity in a setting where it is an occupational requirement.

HYPOTHESIS

Osteochondral allograft transplantation is less successful in returning patients to activity in a population in which physical fitness is a job requirement as opposed to a recreational goal.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review was conducted of 38 consecutive OATS procedures performed at a single military institution by 1 of 4 sports medicine fellowship-trained orthopaedic surgeons. All patients were on active duty at the time of the index procedure, and data were collected on demographics, return to duty, Knee Injury and Osteoarthritis Outcome Score (KOOS), and ultimate effect on military duty. Success was defined as the ability to return to the preinjury military occupational specialty (MOS) with no duty-limiting restrictions.

RESULTS

The mean lesion size treated was 487.0 ± 178.7 mm(2). The overall rate of return to full duty was 28.9% (11/38). An additional 28.9% (11/38) were able to return to limited activity with permanent duty modifications. An alarming 42.1% (16/38) were unable to return to military activity because of their operative knee. When analyzed for return to sport, only 5.3% (2/38) of patients were able to return to their preinjury level. Eleven patients underwent concomitant procedures. Statistical power was maintained by analyzing data in aggregate for cases with versus without concomitant procedures. When the 11 undergoing concomitant procedures were removed from the data set, the rate of return to full activity was 33.3% (9/27), with 22.3% (6/27) returning to limited activity and 44.4% (12/27) unable to return to activity. In this subset, 7.4% (2/27) were able to return to a preinjury level of sport. The KOOS values were significantly higher in the full activity group when compared with the limited and no activity groups (P < .01). Branch of service was a significant predictor of outcome, with Marine Corps and Navy service members more likely to return to full activity compared with Army and Air Force members. A MOS of combat arms was a significant predictor of a poor outcome. All patients demonstrated postoperative healing of their grafts as documented in their medical chart, and no patient in the series required revision for problems with graft incorporation.

CONCLUSION

Osteochondral allograft transplantation for the treatment of large chondral defects in the knee met with disappointing results in an active-duty population and was even less reliable in returning this population to preinjury sport levels. Branch of service and occupational type predicted the return to duty, but other traditional predictors of outcome such as rank and years of service did not. The presence of concomitant procedures did not have an effect on outcome with respect to activity or sport level with the numbers available for analysis.

One-step arthroscopic technique for the treatment of osteochondral lesions of the knee with bone-marrow-derived cells: three years results

Osteochondral lesions of the knee (OLK) are a common cause of knee pain and associated diseases. A new bone-marrow-derived mesenchymal stem cells technique has been developed for the treatment of OLK. 30 patients with OLK underwent arthroscopic one-step procedure. The bone marrow was harvested from the patients' posterior iliac crest and arthroscopically implanted with a scaffold into the lesion site. Clinical inspection and MRI were performed. Mean International Knee Documentation Committee (IKDC) score before surgery was 29.9 ± 13.2 and 85.4 ± 4.2 at 29 ± 4.1 months (p < 0.0005), while Knee injury and Osteoarthritis Outcome Score (KOOS) before surgery was 35.1 ± 11.9 and 87.3 ± 7.3 at 29 ± 4.1 months (p < 0.0005). Control MRI and bioptic samples showed an osteochondral regeneration of the lesion site. The one-step technique appears to be a good and reliable option for treatment of OLK at three years of follow-up. Level of evidence Case series, Level IV.

Is magnetic resonance imaging reliable in predicting clinical outcome after articular cartilage repair of the knee? A systematic review and meta-analysis

BACKGROUND

While MRI can provide a detailed morphological evaluation after articular cartilage repair, its additional value in determining clinical outcome has yet to be determined.

PURPOSE

To evaluate the correlation between MRI and clinical outcome after cartilage repair and to identify parameters that are most important in determining clinical outcome.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was performed in Embase, MEDLINE, and the Cochrane Collaboration. Articles were screened for relevance and appraised for quality. Guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) Statement were used. Chi-square tests were performed to find variables that could determine correlation between clinical and radiological parameters.

RESULTS

A total of 32 articles (total number of patients, 1019) were included. A majority (81%) were case series or cohort studies that used similar standardized MRI techniques. The mean Coleman score was 63 (range, 42-96). For the majority of MRI parameters, limited or no correlation was found. Nine studies (28%) found a correlation between clinical outcome and the composite magnetic resonance observation of cartilage repair tissue (MOCART) or Henderson score and 7 (22%) with defect fill. In 5 studies, a weak to moderate correlation was found between clinical outcome and the T2 index (mean Pearson coefficient r = .53).

CONCLUSION

Strong evidence to determine whether morphological MRI is reliable in predicting clinical outcome after cartilage repair is lacking. Future research aiming specifically at clinical sensitivity of advanced morphological and biochemical MRI techniques after articular cartilage repair could be of great importance to the field.

Correlation between magnetic resonance imaging and clinical outcomes after cartilage repair surgery in the knee: a systematic review and meta-analysis

BACKGROUND

Magnetic resonance imaging (MRI) is often used to assess cartilage after surgical repair. The correlation between MRI and clinical outcomes is not well understood.

HYPOTHESIS

Postoperative MRI findings correlate with clinical outcome measures in patients after articular cartilage surgery of the knee.

STUDY DESIGN

Meta-analysis.

METHODS

A systematic review of the literature was performed to identify studies in which MRI and clinical outcomes were correlated after autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), or microfracture. Studies that reported correlation coefficients (r) for different MRI parameters were then included in a meta-analysis.

RESULTS

A total of 26 studies were identified for inclusion in this systematic review, 15 of which were included in the meta-analysis. Most of the studies (n = 19) involved ACI, although studies were available for OATS (n = 5) and microfracture (n = 4). The strongest MRI correlates with clinical outcomes after ACI were graft hypertrophy (r = 0.72) and repair tissue signal (r = 0.71). After microfracture, the strongest MRI correlates were the Henderson score (r = 0.97), subchondral edema (r = 0.77), and repair tissue signal (r = 0.76). Correlations after OATS were not as strong, with defect fill (r = 0.53) and repair tissue structure (r = 0.51) being the strongest.

CONCLUSION

The MRI findings do correlate with clinical outcomes after cartilage repair surgery in the knee, although the specific parameters that correlate best vary by the type of procedure performed. No current MRI classification system has been shown to correlate with clinical outcomes after all types of cartilage repair surgery.

Integrated bi-layered scaffold for osteochondral tissue engineering

Osteochondral tissue engineering poses the challenge of combining both cartilage and bone tissue engineering fundamentals. In this study, a sphere-templating technique was applied to fabricate an integrated bi-layered scaffold based on degradable poly(hydroxyethyl methacrylate) hydrogel. One layer of the integrated scaffold was designed with a single defined, monodispersed pore size of 38 μm and pore surfaces coated with hydroxyapatite particles to promote regrowth of subchondral bone while the second layer had 200 μm pores with surfaces decorated with hyaluronan for articular cartilage regeneration. Mechanical properties of the construct as well as cyto-compatibility of the scaffold and its degradation products were elucidated. To examine the potential of the biphasic scaffold for regeneration of osteochondral tissue the designated cartilage and bone layers of the integrated bi-layered scaffold were seeded with chondrocytes differentiated from human mesenchymal stem cells and primary human mesenchymal stem cells, respectively. Both types of cells were co-cultured within the scaffold in standard medium without soluble growth/differentiation factors over four weeks. The ability of the integrated bi-layered scaffold to support simultaneous matrix deposition and adequate cell growth of two distinct cell lineages in each layer during four weeks of co-culture in vitro in the absence of soluble growth factors was demonstrated.

Treatment of osteochondral defects in the rabbit's knee joint by implantation of allogeneic mesenchymal stem cells in fibrin clots

The treatment of osteochondral articular defects has been challenging physicians for many years. The better understanding of interactions of articular cartilage and subchondral bone in recent years led to increased attention to restoration of the entire osteochondral unit. In comparison to chondral lesions the regeneration of osteochondral defects is much more complex and a far greater surgical and therapeutic challenge. The damaged tissue does not only include the superficial cartilage layer but also the subchondral bone. For deep, osteochondral damage, as it occurs for example with osteochondrosis dissecans, the full thickness of the defect needs to be replaced to restore the joint surface (1). Eligible therapeutic procedures have to consider these two different tissues with their different intrinsic healing potential (2). In the last decades, several surgical treatment options have emerged and have already been clinically established (3-6). Autologous or allogeneic osteochondral transplants consist of articular cartilage and subchondral bone and allow the replacement of the entire osteochondral unit. The defects are filled with cylindrical osteochondral grafts that aim to provide a congruent hyaline cartilage covered surface (3,7,8). Disadvantages are the limited amount of available grafts, donor site morbidity (for autologous transplants) and the incongruence of the surface; thereby the application of this method is especially limited for large defects. New approaches in the field of tissue engineering opened up promising possibilities for regenerative osteochondral therapy. The implantation of autologous chondrocytes marked the first cell based biological approach for the treatment of full-thickness cartilage lesions and is now worldwide established with good clinical results even 10 to 20 years after implantation (9,10). However, to date, this technique is not suitable for the treatment of all types of lesions such as deep defects involving the subchondral bone (11). The sandwich-technique combines bone grafting with current approaches in Tissue Engineering (5,6). This combination seems to be able to overcome the limitations seen in osteochondral grafts alone. After autologous bone grafting to the subchondral defect area, a membrane seeded with autologous chondrocytes is sutured above and facilitates to match the topology of the graft with the injured site. Of course, the previous bone reconstruction needs additional surgical time and often even an additional surgery. Moreover, to date, long-term data is missing (12). Tissue Engineering without additional bone grafting aims to restore the complex structure and properties of native articular cartilage by chondrogenic and osteogenic potential of the transplanted cells. However, again, it is usually only the cartilage tissue that is more or less regenerated. Additional osteochondral damage needs a specific further treatment. In order to achieve a regeneration of the multilayered structure of osteochondral defects, three-dimensional tissue engineered products seeded with autologous/allogeneic cells might provide a good regeneration capacity (11). Beside autologous chondrocytes, mesenchymal stem cells (MSC) seem to be an attractive alternative for the development of a full-thickness cartilage tissue. In numerous preclinical in vitro and in vivo studies, mesenchymal stem cells have displayed excellent tissue regeneration potential (13,14). The important advantage of mesenchymal stem cells especially for the treatment of osteochondral defects is that they have the capacity to differentiate in osteocytes as well as chondrocytes. Therefore, they potentially allow a multilayered regeneration of the defect. In recent years, several scaffolds with osteochondral regenerative potential have therefore been developed and evaluated with promising preliminary results (1,15-18). Furthermore, fibrin glue as a cell carrier became one of the preferred techniques in experimental cartilage repair and has already successfully been used in several animal studies (19-21) and even first human trials (22). The following protocol will demonstrate an experimental technique for isolating mesenchymal stem cells from a rabbit's bone marrow, for subsequent proliferation in cell culture and for preparing a standardized in vitro-model for fibrin-cell-clots. Finally, a technique for the implantation of pre-established fibrin-cell-clots into artificial osteochondral defects of the rabbit's knee joint will be described.

Surgical restoration/repair of articular cartilage injuries in athletes

Articular cartilage injuries of the knee are an increasingly common source of pain and dysfunction, particularly in the athletic population. In the athlete, untreated articular cartilage defects can represent a career threatening injury and create a significant obstacle in returning to full athletic participation. The markedly limited healing potential of articular cartilage often leads to continued deterioration and progressive functional limitations. Numerous studies have shown that full thickness articular cartilage lesions are frequently encountered at the time of arthroscopy, particularly associated with athletic injury. A variety of surgical treatment options exist, including debridement, microfracture, osteochondral autograft, osteochondral allograft, and autologous chondrocyte implantation. Each technique has advantages and limitations for restoring articular cartilage function, and emerging technology continues to improve the results of treatment. Our article provides an evidence-based review on the etiology and prevalence of articular cartilage injuries in athletes, along with the principles and techniques available for restoring articular cartilage function following injury.

Matrix assisted autologous chondrocyte transplantation for cartilage treatment: A systematic review

OBJECTIVES

Matrix-assisted autologous chondrocyte transplantation (MACT) has been developed and applied in the clinical practice in the last decade to overcome most of the disadvantages of the first generation procedures. The purpose of this systematic review is to document and analyse the available literature on the results of MACT in the treatment of chondral and osteochondral lesions of the knee.

METHODS

ALL STUDIES PUBLISHED IN ENGLISH ADDRESSING MACT PROCEDURES WERE IDENTIFIED, INCLUDING THOSE THAT FULFILLED THE FOLLOWING CRITERIA: 1) level I-IV evidence, 2) measures of functional or clinical outcome, 3) outcome related to cartilage lesions of the knee cartilage.

RESULTS

The literature analysis showed a progressively increasing number of articles per year. A total of 51 articles were selected: three randomised studies, ten comparative studies, 33 case series and five case reports. Several scaffolds have been developed and studied, with good results reported at short to medium follow-up.

CONCLUSIONS

MACT procedures are a therapeutic option for the treatment of chondral lesions that can offer a positive outcome over time for specific patient categories, but high-level studies are lacking. Systematic long-term evaluation of these techniques and randomised controlled trials are necessary to confirm the potential of this treatment approach, especially when comparing against less ambitious traditional treatments.

Scaffold-based repair for cartilage healing: a systematic review and technical note

PURPOSE

The aim of this systematic review was to address the treatment of chondral and osteochondral knee lesions through the use of scaffolds, by showing surgical options and results of this scaffold-based repair approach for the healing of the articular surface.

METHODS

All studies published in English addressing cartilage scaffold-based treatment were identified, including those that fulfilled the following criteria: (1) Levels I to IV evidence addressing the outlined areas of interest, (2) measures of functional or clinical outcome, (3) knee cartilage lesions, and (4) minimum of 2 years of follow-up.

RESULTS

The analysis showed a progressively increasing number of articles per year from 1995 to February 2012. The number of selected articles was 51, with 40 focusing on 2-step procedures and 11 focusing on 1-step procedures. The evaluation of evidence level showed 3 randomized studies, 10 comparative studies, 33 case series, and 5 case reports.

CONCLUSIONS

Regenerative scaffold-based procedures are emerging as a therapeutic option for the treatment of chondral lesions, but well-designed studies are lacking. Systematic long-term evaluation of these techniques and randomized studies are necessary to confirm the potential of this treatment approach, especially compared with the available traditional treatments. Different 1-step scaffold-based strategies are emerging to simplify the procedure and reduce costs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Treatment of cartilage lesions: what works and why?

Cartilage injuries have a high incidence and a high impact on society. In an attempt to fulfill patients' expectations and successfully treat this pathology, various techniques have been developed over the years. Treatments proposed for cartilage lesions are described with their rationale and indications, ranging from conservative measures to surgical approaches, reparative or regenerative. Among the numerous and heterogeneous procedures proposed over time to treat cartilage defects none has clearly proven to lead to a hyaline articular surface nor to offer better clinical results. Regenerative procedures have been introduced as ambitious techniques that aim to overcome the limitations of the more traditional reparative approaches and restore the articular surface with a hyaline-like tissue; improvement in tissue engineering with new scaffolds as well as new regenerative options involving growth factors or MSCs are currently being investigated as promising solutions to further improve the treatment of cartilage lesions. However, the current literature findings are not conclusive. Randomized controlled trials are necessary to evaluate new regenerative approaches, to show clearly advantages and disadvantages with respect to the more traditional procedures, besides their potential, limits, and indications to improve the treatment of patients affected by chondral and osteochondral lesions. Since clear and commonly accepted treatment algorithms are not available in the literature, the massively increasing number of controversial results may be confusing for the orthopaedic surgeon who has to choose the proper management of patients with cartilage lesions. Thus, the results obtained through the study of the authors' 20 years' experience in cartilage treatment were analyzed to give some indications on the potential and limits of different treatment approaches available in clinical practice.

Fresh osteochondral allograft is a suitable alternative for wide cartilage defect in the knee

INTRODUCTION

There are several surgical options to restore a wide osteochondral defect in the knee. Fresh osteochondral allografts are usually considered a poor alternative due to their difficulties in surgical application. The aim of this work is first to present our experience including the surgical technique and the functional results of patients receiving fresh osteochondral allograft to restore major knee lesions, then, to compare our results with other results presented in literature.

METHODS

Between 2006 and 2011, we treated 11 patients with osteochondral lesion of the knee (Outerbridge IV°). The average lesion size was 10.3 cm(2) (range 3-20 cm(2)). The average age was 34 years (range 18-66). Patients were followed from 12 to 55 months (average of 26.5) through clinical examination, X-ray film and MRI every 3 months for the first year, then every 6 months.

RESULTS

The treatment was successful in 10 patients showing pain regression and mean IKDC subjective score improvements from 27.3 to 58.7. The IKDC objective score also improved of at least one class for each patient except the who failed. The radiographs show good osteointegration in all cases but one.

CONCLUSIONS

Fresh allograft is an effective therapy for osteochondral defects repair because it allows functional recovery in a considerable number of patients. This technique obtains better results in lesion smaller than 8 cm(2). However larger lesion show good results.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Ten-year follow-up of a prospective, randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint of athletes

BACKGROUND

Various techniques have proven to be effective for treating articular cartilage defect (ACD) and osteochondral defect (OCD) of the knee joint, but knowledge regarding which method is best still remains uncertain.

PURPOSE

To evaluate and compare the outcomes of mosaic-type osteochondral autologous transplantation (OAT) and microfracture (MF) procedures for the treatment of articular cartilage defects of the knee joint in young active athletes. This article represents an update of the clinical results at 10 years.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Between 1998 and 2002, a total of 60 athletes with a mean age of 24.3 years (range, 15-40 years) and with a symptomatic ACD or OCD in the knee were randomized to undergo either OAT or MF. Patients were then evaluated postoperatively using the International Cartilage Repair Society (ICRS) score, Tegner activity score, radiographs, and magnetic resonance imaging. The mean follow-up time was 10.4 years (range, 9-11 years).

RESULTS

Three to 10 years after the OAT and MF procedures, patients had lower ICRS and Tegner scores (P < .05), but both groups still had significant clinical improvement over presurgery scores according to ICRS scores at 10-year follow-up. Statistically significantly better results were detected in patients in the OAT group compared with those in the MF group at 10 years (P < .005). At 10-year follow-up, there were 15 failures (26%), including 4 failures (14%) of the OAT and 11 failures (38%) of MF treatment (P < .05). Seven patients (25%) from the OAT group and 14 patients (48%) from the MF group had radiographic evidence of Kellgren-Lawrence grade I osteoarthritis at 10 years, but these differences were not significant (P = .083) or related to the clinical results. The ICRS and Tegner scores of younger athletes (<25 years at the time of primary surgery) remained significantly higher after 10 years compared with older patients (P < .05); 15 of 20 patients (75%) in the OAT group and 8 of 22 patients (37%) in the MF group maintained the same physical activity level.

CONCLUSION

The OAT technique for ACD or OCD repair in the athletic population allows for a higher rate of return to and maintenance of sports at the preinjury level compared with MF.

Arthroscopic second generation autologous chondrocytes implantation associated with bone grafting for the treatment of knee osteochondritis dissecans: Results at 6 years

PURPOSE

The aim of this study was to analyze the clinical outcome obtained with arthroscopic second generation autologous chondrocyte implantation (ACI) associated with bone grafting for the treatment of knee osteochondritis dissecans (OCD) at medium term follow-up.

METHODS

Thirty-four knees affected by symptomatic OCD grade III or IV on the ICRS (International Cartilage Repair Society) scale were treated and prospectively evaluated at 12, 24 months of follow-up, and at a final mean 6 ± 1 years of follow-up. The mean age at treatment was 21 ± 6 years. The average size of the defects was 3 ± 1cm(2). Patients were evaluated with IKDC, EQ-VAS, and Tegner scores.

RESULTS

A statistically significant improvement in all scores was observed after the treatment. The IKDC subjective score improved from 38 ± 13 to 81 ± 20, and 91% of the knees were rated as normal or nearly normal in the objective IKDC at the final evaluation. EQ-VAS and Tegner scores showed a statistically significant linear trend of improvement over time passing from 52 ± 18 to 83 ± 14 and from 2 ± 1 to 5 ± 3, respectively, at 6 years' follow-up. A better outcome was obtained in men, sport active patients, and smaller lesions.

CONCLUSIONS

Second generation ACI associated with bone grafting is a valid treatment option for knee OCD and may offer a good and stable clinical outcome at mean 6 years of follow-up. Further studies are needed to confirm the results over time, and determine if there is only a symptomatic improvement, or if this procedure may also prevent or delay further knee degeneration.

Tissue engineering and regenerative medicine: history, progress, and challenges

The past three decades have seen the emergence of an endeavor called tissue engineering and regenerative medicine in which scientists, engineers, and physicians apply tools from a variety of fields to construct biological substitutes that can mimic tissues for diagnostic and research purposes and can replace (or help regenerate) diseased and injured tissues. A significant portion of this effort has been translated to actual therapies, especially in the areas of skin replacement and, to a lesser extent, cartilage repair. A good amount of thoughtful work has also yielded prototypes of other tissue substitutes such as nerve conduits, blood vessels, liver, and even heart. Forward movement to clinical product, however, has been slow. Another offshoot of these efforts has been the incorporation of some new exciting technologies (e.g., microfabrication, 3D printing) that may enable future breakthroughs. In this review we highlight the modest beginnings of the field and then describe three application examples that are in various stages of development, ranging from relatively mature (skin) to ongoing proof-of-concept (cartilage) to early stage (liver). We then discuss some of the major issues that limit the development of complex tissues, some of which are fundamentals-based, whereas others stem from the needs of the end users.

OSTEOCHONDRAL AUTOLOGOUS TRANSPLANTATION FOR TREATING CHONDRAL LESIONS IN THE PATELLA

Objective: The primary aim of this study was to assess the clinical and functional evolution of patients with total-thickness symptomatic cartilaginous injury of the patellar joint surface, treated by means of osteochondral autologous transplantation. Methods: This prospective study was conducted from June 2008 to March 2011 and involved 17 patients. The specific questionnaires of Lysholm, Kujala and Fulkerson were completed preoperatively and one year postoperatively in order to assess the affected knee, and SF-36 was used to assess these patients’ general quality of life. The nonparametric paired Wilcoxon test was used for statistical analysis on the pre and postoperative questionnaires. The data were analyzed using the SPSS for Windows software, version 16.0, and a significance level of 5% was used. Results: The Lysholm preoperative and postoperative average scores were 54.59 and 75.76 points (p < 0.05). The Fulkerson pre and postoperative average scores were 52.53 and 78.41 points (p < 0.05). Conclusions: We believe that autologous osteochondral transplantation is a good treatment method for total-thickness symptomatic chondral lesions of the joint surface of the patella.

Return to athletic activity after osteochondral allograft transplantation in the knee

BACKGROUND

Fresh-stored osteochondral allografts have been used successfully to resurface large chondral and osteochondral defects of the knee. However, there are limited data available for the return to athletic activity.

PURPOSE

To review the rate of return to athletic activity after osteochondral allograft transplantation in the knee and to identify any potential risk factors for not returning to sport.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Forty-three athletes were treated with fresh-stored osteochondral allograft transplantation for symptomatic large chondral or osteochondral defects of the knee from 2000 to 2010. The average age of the athletes (30 men, 13 women) was 32.9 years (range, 18-49 years). Patients were prospectively evaluated by International Knee Documentation Committee (IKDC), activities of daily living scale of the Knee Injury and Osteoarthritis Outcome Score (KOOS), Marx Activity Rating Scale, and Cincinnati Sports Activity Scale scores. A multivariable regression analysis was performed to identify potential risk factors for failure to return to sport at the preinjury level.

RESULTS

At an average 2.5-year follow-up, limited return to sport was possible in 38 of 43 athletes (88%), with full return to the preinjury level achieved in 34 of 43 athletes (79%). In these 34 athletes, time to return to sport was 9.6 ± 3.0 months. Age ≥25 years (P = .04) and preoperative duration of symptoms greater than 12 months (odds ratio, 37; P = .003) negatively affected the ability to return to sport. In the athletes who returned to their previous level of competition, IKDC (P < .001), KOOS (P = .02), and Marx Activity Rating Scale (P < .001) scores were all significantly greater than in those athletes who did not return to sport.

CONCLUSION

Osteochondral allograft transplantation in an athletic population for chondral and osteochondral defects in the knee allows for a high rate of return to sport. Risk factors for not returning to sport included age ≥25 years and preoperative duration of symptoms ≥12 months.

Current concepts for rehabilitation and return to sport after knee articular cartilage repair in the athlete

Articular cartilage injury is observed with increasing frequency in both elite and amateur athletes and results from the significant acute and chronic joint stress associated with impact sports. Left untreated, articular cartilage defects can lead to chronic joint degeneration and athletic and functional disability. Treatment of articular cartilage defects in the athletic population presents a therapeutic challenge due to the high mechanical demands of athletic activity. Several articular cartilage repair techniques have been shown to successfully restore articular cartilage surfaces and allow athletes to return to high-impact sports. Postoperative rehabilitation is a critical component of the treatment process for athletic articular cartilage injury and should take into consideration the biology of the cartilage repair technique, cartilage defect characteristics, and each athlete's sport-specific demands to optimize functional outcome. Systematic, stepwise rehabilitation with criteria-based progression is recommended for an individualized rehabilitation of each athlete not only to achieve initial return to sport at the preinjury level but also to continue sports participation and reduce risk for reinjury or joint degeneration under the high mechanical demands of athletic activity.

Surgical treatment for early osteoarthritis. Part I: cartilage repair procedures

Young patients with early osteoarthritis (OA) represent a challenging population due to a combination of high functional demands and limited treatment options. Conservative measures such as injection and physical therapy can provide short-term pain relief but are only palliative in nature. Joint replacement, a successful procedure in the older population, is controversial in younger patients, who are less satisfied and experience higher failure rates. Therefore, while traditionally not indicated for the treatment of OA, cartilage repair has become a focus of increased interest due to its potential to provide pain relief and alter the progression of degenerative disease, with the hope of delaying or obviating the need for joint replacement. This review of cartilage repair techniques will discuss currently available procedures, specifically pertaining to experiences in the setting of early OA. Level of evidence IV.

Management of articular cartilage defects of the knee

Articular cartilage injuries of the knee present a difficult clinical dilemma and their treatment is controversial. Hyaline articular cartilage is an avascular, low-friction, and wear-resistant weightbearing surface that has limited capacity for self-repair. The optimal treatment for cartilage lesions has yet to be established. Various treatment methods are employed to reestablish a stable cartilage surface, including microfracture, autologous and allograft osteochondral transplantation, autologous chondrocyte implantation, matrix-associated chondrocyte implantation, and scaffold-assisted methods. Treatment algorithms help to guide physicians' decision making in the care of these injuries. In this article, results from outcomes studies as well as prospective randomized clinical trials comparing treatment methods are reviewed, and current practice guidelines are summarized.

Rehabilitation following osteochondral injury to the knee

Articular cartilage injuries of the knee can be debilitating if not treated properly. Once an articular cartilage injury is sustained there are a variety of surgical interventions depending on the severity of the injury. The most common of these procedures are: osteochondral autograft transplantation (OATS), autologous chondrocyte implantation (ACI) and microfracture. The rehabilitation outlined in this article is specific to the exact surgical procedure performed and the location in the knee. The outcomes of these procedures are also discussed.

Return to Sports after Articular Cartilage Repair in the Football (Soccer) Player

BACKGROUND

The ability to return to football (soccer) presents a critical aspect for successful treatment of articular cartilage injury in the football (soccer) player.

METHODS

Information about sports participation after articular cartilage repair was collected from the literature. Special focus was placed on data in football athletes with information on return rate, timing of return, level of postoperative competition, and the ability to compete in the sport over time.

RESULTS

Twenty studies describing 1,469 athletes including football players with articular cartilage injury were reviewed. Average return to sport was 79% without a significant difference in return rate or postoperative level of play between cartilage repair techniques. Time to return varied between 7 to 17 months, with the longest time for autologous chondrocyte transplantation (ACI). Advanced sport-specific rehabilitation was able to reduce recovery time. Durability of results was best after ACI, with up to 96% continued sport participation after more than 3 years. Player age, time between injury and treatment, competitive level, defect size, and repair tissue morphology affected the ability to return to play. Sports participation after cartilage repair generally promoted joint restoration and functional recovery.

CONCLUSIONS

Articular cartilage repair allows for a high rate of return to high-impact sports including football, often at the preinjury competitive level. The time of return and durability can be variable and depend on repair technique and athlete-specific factors. Advanced, sport-specific rehabilitation can facilitate return to football.

A moderate-intensity static magnetic field enhances repair of cartilage damage in rabbits

BACKGROUND AND AIMS

Electromagnetic fields have been proposed to enhance healing of cartilage defects by stimulation of chondrocyte proliferation, proteoglycan synthesis as well as decreasing pain and improving motion in osteoarthritic patients. However, the effects of a moderate-intensity static magnetic field on cartilage repair have not been investigated. This study tries to determine the effects of a moderate-intensity permanent magnetic field of 40 mT on cartilage repair.

METHODS

Defects of 3 mm in diameter and 6 mm in depth were made on the weight bearing surface of the right medial femoral condyle of 30 rabbits. The animals were divided randomly into three equal groups (magnet, sham and control). In the magnet group, cylindrical permanent magnets were implanted subcutaneously medial to the medial femoral condyle, while in the sham group the cylindrical ceramic were not magnetized, and nothing was implanted in controls. After 12 weeks of observation, Mankin's microscopic scoring was done on all specimens, and irregularity of surface characteristics, cell colonization, hypocellularity, cartilage matrix formation, and presence of empty lacunae were investigated.

RESULTS

Each of these characteristics showed significant differences in magnet group relative to control and sham groups (p <0.05). Mankin's score was 1.6 ± 0.6 in magnet group, 7.2 ± 1.6 in sham group and 7.7 ± 1 in control group (p <0.001).

CONCLUSIONS

[corrected] In this animal study, microscopic Mankin's scoring depicted histological improvement in cartilage of magnet group.

Treatment of knee cartilage defect in 2010

Treatment of knee cartilage defect, a true challenge, should not only reconstruct hyaline cartilage on a long-term basis, but also be able to prevent osteoarthritis. Osteochondral knee lesions occur in either traumatic lesions or in osteochondritis dissecans (OCD). These lesions can involve all the articular surfaces of the knee in its three compartments. In principle, this review article covers symptomatic ICRS grade C or D lesions, depth III and IV, excluding management of superficial lesions, asymptomatic lesions that are often discovered unexpectedly, and kissing lesions, which arise prior to or during osteoarthritis. For clarity sake, the international classifications used are reviewed, for both functional assessment (ICRS and functional IKDC for osteochondral fractures, Hughston for osteochondritis) and morphological lesion evaluations (the ICRS macroscopic evaluation for fractures, the Bedouelle or SOFCOT for osteochondritis, and MOCART for MRI). The therapeutic armamentarium to treat these lesions is vast, but accessibility varies greatly depending on the country and the legislation in effect. Many comparative studies have been conducted, but they are rarely of high scientific quality; the center effect is nearly constant because patients are often referred to certain centers for an expert opinion. The indications defined herein use algorithms that take into account the size of the cartilage defect and the patient's functional needs for cases of fracture and the vitality, stability, and size of the fragment for cases of osteochondritis dissecans. Fractures measuring less than 2 cm(2) are treated with either microfracturing or mosaic osteochondral grafting, between 2 and 4 cm(2) with microfractures covered with a membrane or a culture of second- or third-generation chondrocytes, and beyond this size, giant lesions are subject to an exceptional allografting procedure, harvesting from the posterior condyle, or chondrocyte culture on a 3D matrix to restore volume. Cases of stable osteochondritis dissecans with closed articular cartilage can be simply monitored or treated with perforation in cases of questionable vitality. Cases of open joint cartilage are treated with a PLUS fixation if their vitality is preserved; if not, they are treated comparably to osteochondral fractures, with the type of filling depending on the defect size.

Mosaic osteochondral transplantations in the knee joint, midterm results of the SFA multicenter study

INTRODUCTION

There are several possible options to treat focal articular cartilage defects of the knee. The aim of this study was to evaluate the results and prognostic factors cartilage defects of the knee treated by autologous osteochondral mosaicplasty after more than five years of follow-up.

PATIENTS AND METHODS

One hundred forty-two cases were included in this retrospective multicenter study. Etiologies included osteochondral fractures (n=79), and osteochondritis dissecans (n=61). Mean age of patients was 31. There was a majority of men (76%). Mean BMI was 25 (range: 21-41). Fifty-three percent of the knees had a history of surgery. Mean delay between the accident and surgery was 2.5 years. Mean area of the defect was 2.29 cm(2) (range: 0.3-12.25 cm(2)). The depth of the defect was 3 or 4 on the ICRS score in 97% of cases. An additional surgical procedure was associated with mosaicplasty in 14% of the cases. The follow-up evaluation was based on the Hughston score, the ICRS score, the IKDC subjective score, and the IKDC radiological score. Evaluation of control MRI was based on a modified MOCART score.

RESULTS

The mean follow-up was 96 ± 28 months. There were complications in 19 patients. Patients were able to begin athletic activities again after a mean 35 weeks. Most patients (81.8%) were satisfied or very satisfied. There was a significant improvement (p<0.001) in the ICRS, IKDC function and Hughston scores at follow-up. The factors for a good prognosis were: male gender, medial femoral condyle defects, osteochondritis dissecans, deep, small defects, and the shortest possible delay to surgery. Obesity, smoking, work-related accidents, the level of sports practiced, the percentage of coverage of the defect, the number of plugs, and associated lesions did not have a statistically significant effect on the functional results in the final follow-up.

DISCUSSION

Autologous osteochondral mosaicplasty seems to be a reliable technique in the short and intermediate term. It has the advantage of being less expensive than reconstructive techniques, is a one-step surgical procedure and results in immediate restoration of cartilage surface. Nevertheless, this is a difficult technique, which may result in complications and requires articular harvesting. This technique is limited by the size of the defect to be treated. The primary indication is deep, small defects on the medial femoral condyle.

MR imaging assessment of articular cartilage repair procedures

Because articular cartilage is avascular and has no intrinsic capacity to heal itself, physical damage to cartilage poses a serious clinical problem for orthopedic surgeons and rheumatologists. No medication exists to treat or reconstitute physical defects in articular cartilage, and pharmacotherapy is limited to pain control. Developments in the field of articular cartilage repair include microfracture, osteochondral autografting, osteochondral allografting, repair with synthetic resorbable plugs, and autologous chondrocyte implantation. MR imaging techniques have the potential to allow in vivo monitoring of the collagen and proteoglycan content of cartilage repair tissue and may provide useful additional metrics of cartilage repair tissue quality.

Biofabrication of osteochondral tissue equivalents by printing topologically defined, cell-laden hydrogel scaffolds

Osteochondral defects are prone to induce osteoarthritic degenerative changes. Many tissue-engineering approaches that aim to generate osteochondral implants suffer from poor tissue formation and compromised integration. This illustrates the need for further improvement of heterogeneous tissue constructs. Engineering of these structures is expected to profit from strategies addressing the complexity of tissue organization and the simultaneous use of multiple cell types. Moreover, this enables the investigation of the effects of three-dimensional (3D) organization and architecture on tissue function. In the present study, we characterize the use of a 3D fiber deposition (3DF) technique for the fabrication of cell-laden, heterogeneous hydrogel constructs for potential use as osteochondral grafts. Changing fiber spacing or angle of fiber deposition yielded scaffolds of varying porosity and elastic modulus. We encapsulated and printed fluorescently labeled human chondrocytes and osteogenic progenitors in alginate hydrogel yielding scaffolds of 1×2 cm with different parts for both cell types. Cell viability remained high throughout the printing process, and cells remained in their compartment of the printed scaffold for the whole culture period. Moreover, distinctive tissue formation was observed, both in vitro after 3 weeks and in vivo (6 weeks subcutaneously in immunodeficient mice), at different locations within one construct. These results demonstrate the possibility of manufacturing viable centimeter-scaled structured tissues by the 3DF technique, which could potentially be used for the repair of osteochondral defects.