BACKGROUND: Osteochondral lesions of the talar dome (OLTD) are most often found in patients for whom the return to sports activities is the main issue. Two types of surgery have been distinguished at present, bone marrow stimulation techniques and mosaicplasty techniques. The size of the lesion indicating the need for bone marrow stimulation as the required surgical procedure has recently been decreased (<1cm). The main objective of this study was therefore to evaluate the return to sport after OLTD surgery. Our hypothesis is that surgery of osteochondral lesions of the talar dome allows the resumption of sports activities in the majority of cases.
METHODS: This multicenter prospective study was conducted across 10 French centers specializing in foot and ankle surgery. All patients aged 18 to 65 with symptomatic OLTD resistant to thorough medical treatment for at least 6 months, justifying surgery, were included from June 2018 to September 2019. In addition to the usual demographic data, the practice of sport and level (professional, competitive, leisure) were systematically investigated preoperatively. A common protocol for surgical management and postoperative follow-up had previously been established according to the arthrographic stage of the lesion. The most recent recommendations based on size, but also depth, were taken into account. The primary endpoint was return to sport.
RESULTS: A final functional evaluation with the AOFAS (American Orthopedic Foot & Ankle Society) score was performed at a minimum of 12 months. Of 58 sports patients, 70.6% returned to sport (41/58) with an average delay of 4.3 months. A high AOFAS functional score (p=0.02) and a stage 1 lesion (p=0.006) were the only preoperative criteria significantly associated with a return to sport. No other factor was predictive of a return to sport.
CONCLUSIONS: Our prospective study shows that 70.6% of sports patients returned to sport after OLTD surgery according to a surgical protocol and standardized follow-up.
METHODS: II.

To investigate survival of cartilage repair in the knee by microfracture (MFX; n = 119) or mosaicplasty osteochondral autograft transfer (OAT; n = 84).
For survival analyses, \"failure\" was defined as the event of a patient reporting a Lysholm score <65 or undergoing an ipsilateral knee replacement. The Kaplan-Meier method was used for construction of a survival functions plot for the event \"failure.\" Log rank (Mantel-Cox) test was used for comparison of survival distributions in the 2 groups.
The long-term failure rate (62% overall) was significantly higher in the MFX group (66%) compared with the OAT group (51%, P = 0.01). Furthermore, the mean time to failure was significantly shorter (P < 0.001) in the MFX group, 4.0 years (SD 4.1) compared with the OAT group, 8.4 years (SD 4.8). In the OAT group, the survival rate stayed higher than 80% for the first 7 years, and higher than 60% for 15 years, while the survival rate dropped to less than 80% within 12 months, and to less than 60% within 3 years in the MFX group, log rank (Mantel-Cox) 20.295 (P < 0.001). The same pattern was found in a subgroup of patients (n = 134) of same age (<51 years) and size of treated lesion (<500 mm2), log rank (Mantel-Cox) 10.738 (P = 0.001). The nonfailures (48%) were followed for median 15 yeas (1-18 years).
MFX articular cartilage repairs failed more often and earlier than the OAT repairs, both in the whole cohort and in a subgroup of patients matched for age and size of treated lesion, indicating that the OAT repair is the more durable.
Therapeutic study, Level III.

BACKGROUND: Few comparative randomized long-term studies on microfracture versus mosaicplasty have been published, and only 2 studies reported a follow-up of 10 years. Hypothesis/Purpose: The purpose was to compare the clinical outcome of microfracture versus mosaicplasty/osteochondral autograft transfer in symptomatic cartilage lesions. The null hypothesis was that the outcome was not statistically different at any point of time.
METHODS: Randomized controlled trial; Level of evidence, 1.
METHODS: Forty patients with articular cartilage defects were randomized to undergo cartilage repair by either microfracture (n = 20) or mosaicplasty (n = 20). Inclusion criteria were as follows: age 18 to 50 years at the time of surgery, 1 or 2 symptomatic focal full-thickness articular chondral defects on the femoral condyles or trochlea, and size 2 to 6 cm2. The main outcome variable was the Lysholm knee score recorded before the surgery and at 12 months, median 5 years, median 10 years, and minimum 15 years after the surgery.
RESULTS: Forty patients were included in the study (28 men, 12 women; median age, 32 years; range, 18-48 years). Defects with a median size of 3.5 cm2 (range, 2-5 cm2) were treated. A significant increase in the Lysholm score was seen for all subjects- from a mean 53 (SD, 16) at baseline to 69 (SD, 21) at the minimum 15-year follow-up ( P = .001). The mean Lysholm score was significantly higher in the mosaicplasty group than the microfracture group at 12 months, median 5 years, median 10 years, and minimum 15 years: 77 (SD, 17) versus 61 (SD, 22), respectively ( P = .01), at the last follow-up. At all follow-up time points, the difference in mean Lysholm score was clinically significant (>10 points).
CONCLUSIONS: At short, medium, and long term (minimum 15 years), mosaicplasty results in a better, clinically relevant outcome than microfracture in articular cartilage defects (2-5 cm2) of the distal femur of the knee in patients aged 18 to 50 years.

The purpose of this study was to evaluate changes in biomarker and synovial parameters following autologous osteochondral transplantation (AOT) in the equine stifle joint, to test the hypothesis whether synovial parameters would show significant differences at selected time points following the surgery (at days 3, 14, 60 and 180) compared to baseline level (at day 0). Surgical intervention was performed in both stifles of nine horses (n = 18). The joints were randomly assigned to operated and sham-operated groups. Grafts 8.5 mm in diameter were harvested from the femoropatellar (FP) joint under arthroscopic control and the medial femorotibial (MFT) joints had AOT using mosaicplasty (MP) instrumentation, while the sham FP and sham MFT joints underwent arthroscopy and miniarthrotomy without transplantation, respectively. Synovial fluid (SF) parameters were evaluated at days 4, 14, 60 and 180. Data were analysed by two-way repeated- measures analysis of variance (ANOVA), and P < 0.05 was considered significant. During the first 10-14 days after surgery, lameness of degree 2-3/5 [American Association of Equine Practitioners (AAEP) scores] was present, which disappeared after 60 days. Joints with transplantation showed significant increases in synovial white blood cell count (WBC), total protein (TP), substance P, C1,2C and CS846 epitope concentration at day 3 compared to baseline and shamoperated joints (P < 0.05). These parameters returned to the baseline values by two months after surgery and remained within normal levels at 6 months postoperatively.

Numerous surgical techniques have been developed to treat osteochondral defects of the knee. A study reported encouraging outcomes of third-generation autologous chondrocyte implantation achieved using the solid agarose-alginate scaffold Cartipatch®. Whether this scaffold is better than conventional techniques remains unclear. This multicenter randomized controlled trial compared 2-year functional outcomes (IKDC score) after Cartipatch® versus mosaicplasty in patients with isolated symptomatic femoral chondral defects (ICRS III and IV) measuring 2.5-7.5 cm(2) . In addition, a histological evaluation based on the O\'Driscoll score was performed after 2 years. We needed 76 patients to demonstrate an at least 10-point subjective IKDC score difference with α = 5% and 90% power. During the enrolment period, we were able to include 55 patients, 30 of them were allocated at random to Cartipatch® and 25 to mosaicplasty. After 2 years, eight patients had been lost to follow-up, six in the Cartipatch® group, and two in the mosaicplasty group. The baseline characteristics of the two groups were not significantly different. The mean IKDC score and score improvement after 2 years were respectively 73.7 ± 20.1 and 31.8 ± 20.8 with Cartipatch® and 81.5 ± 16.4 and 44.4 ± 15.2 with mosaicplasty. The 12.6-point absolute difference in favor of mosaicplasty is statistically significant. Twelve adverse events were recorded in the Cartipatch® group against six in the mosaicplasty group. After 2 years, functional outcomes were significantly worse after Cartipatch® treatment compared to mosaicplasty for isolated focal osteochondral defects of the femur.

OBJECTIVE: To investigate the feasibility of repairing osteochondral defects of critical size by performing mosaicplasty using multiple sliced costal cartilage grafts, which enables repair of extensively injured knees using grafts from a single rib.
METHODS: Critical osteochondral defects were prepared on the femoral groove of skeletally mature Japanese white rabbits. Costal cartilage grafts from a single rib were harvested and sliced into multiple segments (approximately 3-5 mm in length). The defects were left untreated or repaired by performing mosaicplasty using costal cartilage grafts (with or without a longitudinal cut along the middle). At 4 and 12 weeks after transplantation, International Cartilage Repair Society macroscopic and histological grading was performed.
RESULTS: The macroscopic score and visual histological score were significantly higher in the repaired groups than in the untreated group at 4 and 12 weeks after surgery. Histological continuous integration between grafted costal cartilage and host bone was observed in both repaired groups.
CONCLUSIONS: The findings suggest that costal cartilage might be a useful alternative source for chondral grafting. We were able to repair large osteochondral defects by performing mosaicplasty using multiple sliced costal cartilage grafts from a single rib.

One Arabian and 5 Hungarian half-bred horses were used to study the macroscopic and microscopic survival of autologous osteochondral grafts in the weight-bearing surface of the medial femoral condyle (MFC). Grafts were harvested from the cranial surface of the medial femoral trochlea (MFT) under arthroscopic control. Three of them were transplanted into the weight-bearing surface of the contralateral MFC using an arthrotomy approach. Three months later this transplantation procedure was repeated on the opposite stifle joints in the same animals, but at that time transplantation was performed arthroscopically. Follow-up arthroscopy was carried out 12 months after the first operations, and biopsies were taken from both the recipient and the donor sites for histological examination. During follow-up arthroscopy, the transplanted areas looked congruent and smooth. Microscopically, the characteristics of hyaline cartilage were present in 5 out of the 10 biopsies examined; however, in the other half of biopsies glycosaminoglycan (GAG) loss and change in the architecture of the transplanted cartilage was observed. In a 16-year-old horse, all grafts broke during harvesting, and thus transplantation was not performed. No radiological signs of osteoarthritic changes were detected 9 to 12 months after the operations in the donor and recipient joints. Clinically, no lameness or effusion was present three months after the transplantations.