Osteochondritis dissecans (OD) is a rare condition with an incidence of 30/100,000. It especially affects male patients aged 10-20 years old. During the staged progression the osteochondral fragments can detach from their base. These can damage the adjacent articular cartilage, which can lead to premature osteoarthritis. Most commonly affected are the knee, ankle and elbow joints. The exact pathogenesis of OD has so far not been clearly confirmed. Several risk factors that can lead to the development of OD are discussed. These include repeated microtrauma and vascularization disorders that can lead to ischemia of the subchondral bone and to a separation of the fragments close to the joint and therefore to the development of free joint bodies. For an adequate clarification patients should undergo a thorough radiological evaluation including X‑ray imaging followed by magnetic resonance imaging (MRI) to assess the integrity of the cartilage-bone formation with determination of the OD stage. The assessment is based on criteria of the International Cartilage Repair Society (ICRS). The instability of the cartilage-bone fragment increases with higher stages. Stages I and II with stable cartilage-bone interconnection can be treated conservatively. For stages III and IV, i.e., instability of the OD fragment or the presence of free fragments, surgical treatment should be performed. Primarily, refixation of a free joint body should be carried out depending on the size and vitality of the fragment. In cases of unsuccessful conservative treatment or fixation, a debridement, if necessary in combination with a bone marrow stimulating procedure, can be employed corresponding to the size of the defect. For larger cartilage defects, an osteochondral graft transplantation should be considered. Overall, OD lesions in stages I and II show a good healing tendency under conservative treatment. In cases of incipient unstable OD, refixation can also lead to good clinical and radiological results.
UNASSIGNED: Die Osteochondrosis dissecans (OD) ist eine seltene Erkrankung mit einer Inzidenz von 30/100.000. Sie betrifft insbesondere männliche Patienten im Alter von 10 bis 20 Jahren. Im Rahmen des stadienhaften Verlaufs kann es bis zu einer Ablösung des gebildeten osteochondralen Fragments aus seinem Bett kommen. Dies führt zu einer Zerstörung des angrenzenden Gelenkknorpels und kann in eine vorzeitige Arthrose münden. Am häufigsten betroffenen sind das Knie‑, Sprung- und Ellenbogengelenk. Die genaue Pathogenese der OD ist bislang nicht eindeutig belegt. Es werden verschiedene Risikofaktoren diskutiert, die zu einer Entwicklung der OD führen können. Dabei werden wiederholte Mikrotraumata sowie Vaskularisierungsstörungen als Ursachen genannt. Aufgrund dessen kommt es zu einer Ischämie des subchondralen Knochens, die bis zu einer Separierung des gelenknahen Fragmentes und damit zur Entwicklung freier Gelenkkörper führen kann. Eine adäquate Abklärung beinhaltet die Röntgen- sowie MRT(Magnetresonanztomographie)-Bildgebung zur Erhebung des Knorpel-Knochen-Status mit Bestimmung des vorliegenden OD-Stadiums. Die Einteilung der Stadien erfolgt anhand der International Cartilage Repair Society (ICRS). Dabei nimmt mit zunehmendem Stadium die Instabilität des Knorpel-Knochen-Fragments zu. Bei stabilem Knorpel-Knochen-Fragment, kann eine konservative Therapie eingeleitet werden. Bei Anhalt für eine Instabilität des OD-Fragmentes oder Vorliegen eines freien Fragmentes ist ein operatives Prozedere indiziert. Primär sollte in Abhängigkeit der Größe sowie Vitalität des Fragmentes eine Refixation zum Erhalt des Fragmentes erfolgen. Sollte dies nicht möglich sein, kann entsprechend der Defektgröße ein Débridement, ggf. in Kombination mit Knochenmark-stimulierenden Verfahren, angewandt werden. Bei größeren Defekten kann eine Knorpel-Knochen-Transplantation erwogen werden. Insgesamt zeigt die OD im Stadium I und II eine gute Einheilungstendenz unter konservativer Therapie. Bei beginnender instabiler OD kann auch eine Refixierung zu guten klinischen und radiologischen Ergebnissen führen.

Tibiotalocalcaneal arthrodesis (TTCA) using the intramedullary nail has been conducted for severe deformity of both ankle and subtalar joints. While good clinical outcomes have been reported for TTCA, its nonunion rate is relatively high. We report a case of a 65-year-old male with nonunion of the tibiotalar joint and destruction of the subtalar joint after TTCA using a retrograde intramedullary nail. For this patient, we conducted a salvage procedure for the subtalar joint along with revision surgery for the tibiotalar joint to achieve bone union. The intramedullary nail was removed and the tibiotalar joint was debrided. Two osteochondral plugs were harvested from the lateral aspect of the talus and transplanted to the subtalar joint. The tibiotalar joint was fixed using screws and staples, with bone grafting. Magnetic resonance imaging (MRI) at six months after surgery showed that the articular surface of the subtalar joint was flushed and the osteochondral plugs were united with the surrounding bone. At one year and three months after surgery, the pain in the tibiotalar and subtalar joints had completely disappeared. Plain radiographs revealed that bone union of the tibiotalar joint and joint space of the subtalar joint was maintained. Japanese Society for Surgery of the Foot (JSSF) hindfoot scale improved from 53 points to 84 points at the final follow-up. Reconstruction of the subtalar joint using osteochondral autologous transplantation is a useful technique for failure cases with nonunion of the tibiotalar and subtalar joints after TTCA.

This study aimed to analyse the initial results of five patients with symptomatic osteochondral lesions (OCL) and femoroacetabular impingement (FAI) who were treated successfully with osteochondral autologous transfer (OAT) and femoral neck osteochondroplasty (OCP) through surgical dislocation of the hip. Five patients with FAI and OCL of the femoral head who underwent surgery between 2015-2018 were studied retrospectively. All patients had a grade IV OCL, and the median defect size was 2 cm2 (interquartile range [IQR], 2-2). At the final follow-up, the modified Harris hip score showed a median value of 94 (IQR, 91-95) (P=0.04). Pain evaluation using the visual analogue scale showed a median value of 1 (IQR, 1-2) (P=0.04). Adequate graft union and healthy formation of the chondral surface were observed by magnetic resonance imaging. Although the procedure is demanding, the combination of OAT and femoral neck OCP appears to be an effective alternative in young patients.

There are few studies on the clinical outcomes of osteochondral autologous transplantation (OAT) harvesting from local talar non-weight-bearing articular facets for the treatment of osteochondral lesions of the talus (OLTs). The purpose of this study was to review the short- to midterm outcomes of our patients who were treated with OAT harvesting from ipsilateral talar articular facets for OLTs.
Between December 2010 and November 2018, 24 patients were enrolled in this study. There were 16 males and eight females with an average age of 39.1 years and a follow-up period of 50.9 months. The clinical results were evaluated according to the American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS) score. Pre-operative plain radiographs and magnetic resonance imaging (MRI) scans, post-operative radiographs, and X-ray and computed tomography (CT) scans at the last follow-up were observed.
There was a significant improvement in the AOFAS score from 61.3 ± 19.0 pre-operatively to 84.9 ± 9.2 post-operatively (P < 0.001). The VAS score improved from 6.1 ± 2.3 to 2.0 ± 1.4 at the last follow-up (P < 0.001). Twenty-one patients (87.5%) were satisfied with their clinical results. By the last follow-up CT scan, there was bone cyst formation at the donor sites in three patients, at the recipient sites in five patients and at both sites in five patients. Two patients (8.3%) underwent re-operation with arthroscopic debridement because of medial gutter hypertrophic soft tissue impingement.
OAT harvesting from the ipsilateral talar articular facet showed satisfactory results. The mean post-operative VAS score and AOFAS ankle-hindfoot score improved significantly. Post-operative impingement around the osteotomy site was the main complication and reason for re-operation after the index procedure. In addition, bone cysts at the recipient and/or donor site(s) were found with a large percentage under CT. Therefore, longer follow-up is necessary to determine the long-term clinical results for this technique.

BACKGROUND: More than 19% of patients undergoing knee arthroscopies suffers from articular cartilage defects. The chondral or osteochondral lesion has negative impacts on the knee joints function and the life quality of patients. However, the treatment remains challenging as hyaline cartilage is not renewable. The purpose of this study was to systematically analyze the data of randomized controlled trials for comparing the postoperative outcomes between osteochondral autologous transplantation (OAT) and microfracture (MF) procedure. We hypothesized that the outcomes were better in OAT than MF procedure.
METHODS: A systematic literature search of the EMBASE, Pubmed, and Cochrane Library databases was conducted based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The outcome measures include: the rate of excellent or good results, the rate of return to sports, the failure rate, osteoarthritis rate, International Cartilage Repair Society (ICRS) score, Lysholm Knee Score, and Tegner scale. The statistical analysis was completed using Review Manager (RevMan, version 5.3) software.
RESULTS: The systematic search identified 7 studies with a total of 346 patients. The pooled result showed significant differences between the two groups in the rate of return to sports and failure. The following outcome scores showed significant improvement (pre- vs postoperatively): Lysholm score (p = 0.02), Tegner scale (p < 0.00001), and ICRS score (p < 0.00001). The differences were not significant in the excellent or good results and the rate of osteoarthritis.
CONCLUSIONS: The patients in OAT group may return to play quicker, even return to pre-injury level of activity compared to the MF group. OAT is better than MF procedure in accordance with Lysholm score, Tegner score, ICRS score, and the rate of failure. However, few studies have reported long-term outcomes and there has no uniform criteria for safe return to sports. Further research is needed.
METHODS: Level II, meta-analysis of randomized controlled trials.

To compare the results of two groups of patients affected by osteochondritis dissecans (OCD) of the knee and treated with either osteochondral autologous transplantation (OAT) or bone-cartilage paste grafting (PG).
A total of 27 patients affected by OCD lesions of the femoral condyles were included: 15 treated with OAT, 12 with PG, with comparable baseline characteristics (mean age 22.4 ± 7.2 vs. 24.2 ± 8.5 p = n.s., mean defect size 2.2 ± 1 cm2 vs 2.6 ± 1 cm2 p = n.s.). Patients were evaluated pre-operatively and at 24 and 84 months post-operatively with the International Knee Documentation Committee (IKDC) subjective and objective scores. Sport activity level was evaluated with the Tegner activity score. Adverse events and failures were also recorded.
The IKDC subjective score improved significantly in both groups. At 24 months, a significant improvement from 53.4 ± 9.1 to 80.8 ± 12.9 (p = 0.005) was obtained in the OAT group and from 44.6 ± 11.0 to 71.4 ± 25.3 in the PG group (p = 0.008). A further statistically significant increase was observed at 84 months in both groups. No significant differences were found between OAT and PG at both follow-ups. One OAT patient required post-operative knee mobilization under narcosis and two complained of donor site symptoms. More failures were documented in the PG vs OAT group (25% vs 0%; p = 0.043).
Both PG and OAT provided overall satisfactory results up to 84 months follow-up. However, while PG presents the advantages of a less invasive approach with lower adverse events, the higher failure rate of PG should be considered when choosing between these two surgical treatment options for restoration of the articular surface in patients affected by knee OCD.

OBJECTIVE: To explore the effectiveness of arthroscopic microfracture combined with osteochondral autologous transplantation (OAT) in treatment of large area (4-6 cm 2) cartilage injury of the femoral condyle of knee.
METHODS: Between March 2016 and June 2017, 22 patients of large area cartilage injury of the femoral condyle of knee were treated with arthroscopic microfracture combined with OAT. There were 16 males and 6 females with an average age of 22-60 years (mean, 38.6 years). The cause of injury was traffic accident in 8 cases and sports injuries in 14 cases. The disease duration was 1-6 months (mean, 3.4 months). There were 15 cases of medial femoral condyle injuries and 7 cases of lateral condyle injuries. The area of cartilage defect was 4-6 cm 2 (mean, 4.98 cm 2). According to the International Cartilage Repair Society (ICRS) classification, 9 cases were rated as grade Ⅲ and 13 cases as grade Ⅳ. Eighteen cases were combined with meniscus injuries. Preoperative visual analogue scale (VAS) score was 6.36±1.25 and Lysholm score was 36.00±7.77.
RESULTS: All incisions healed by first intention. All patients were followed up 2-3 years with an average of 2.3 years. At 2 years after operation, the VAS score was 1.27±0.94 and the Lysholm score was 77.82±6.21, which were significantly improved when compared with those before operation ( t=16.595, P=0.000; t=21.895, P=0.000). At 2 years after operation, MRI showed that the cartilage defect was repaired well.
CONCLUSIONS: Arthroscopic microfracture combined with OAT can be used to treat large area cartilage injury of the femoral condyle of knee, and the good early effectiveness can be obtained.
UNASSIGNED: 探讨关节镜下微骨折术联合自体骨软骨移植（osteochondral autologous transplantation，OAT）治疗膝关节股骨髁大面积（4～6 cm 2）软骨损伤的疗效。.
UNASSIGNED: 2016 年 3 月—2017 年 6 月，采用关节镜下微骨折术联合 OAT 治疗 22 例膝关节股骨髁大面积软骨损伤患者。其中男 16 例，女 6 例；年龄 22～60 岁，平均 38.6 岁。致伤原因：交通事故伤 8 例，运动损伤 14 例。病程 1～6 个月，平均 3.4 个月。股骨内侧髁损伤 15 例，外侧髁损伤 7 例；软骨损伤面积 4～6 cm 2，平均 4.98 cm 2。软骨损伤国际软骨修复协会（ICRS）分级：Ⅲ级 9 例，Ⅳ级 13 例。伴半月板损伤 18 例。术前疼痛视觉模拟评分（VAS）为（6.36±1.25）分，Lysholm 评分为（36.00±7.77）分。.
UNASSIGNED: 术后切口均Ⅰ期愈合。患者均获随访，随访时间 2～3 年，平均 2.3 年。术后 2 年时 VAS 评分为（1.27±0.94）分，Lysholm 评分为（77.82±6.21）分，均较术前明显改善（ t=16.595， P=0.000； t=21.895， P=0.000）。术后 2 年，MRI 显示软骨缺损区修复良好。.
UNASSIGNED: 关节镜下微骨折术联合 OAT 治疗膝关节股骨髁大面积软骨损伤早期疗效较好。.

This study aimed to compare the clinical results between osteochondral autologous transplantation (OAT) and dorsiflexion closing wedge metatarsal osteotomy (DCWMO) in symptomatic adult patients with late-stage Freiberg disease.
Between 2012 and 2017, patients with late-stage Freiberg disease surgically treated with OAT (12 patients) or DCWMO (15 patients) were retrospectively identified. The American Orthopaedic Foot & Ankle Society-lesser metatarsophalangeal-interphalangeal (AOFAS-LMI) score, visual analog scale score for subjective pain, and range of motion (ROM) were determined preoperatively and at final follow-up. Postoperative complications were also recorded.
The AOFAS-LMI score at final follow-up was significantly greater in the OAT group than in the DCWMO group (95.7 vs 87.9, P < .001), whereas plantarflexion at final follow-up was significantly lower in the DCWMO group than in the OAT group (30.0 vs 24.0 degrees, P = .037). The DCWMO group reported more postoperative complications including postoperative joint stiffness, deformity, and pain recurrence. In the OAT group, one patient complained of mild knee pain.
OAT seemed a better procedure for late-stage Freiberg disease compared with DCWMO in adult patients in terms of postoperative functional score and ROM, with lower complication rates.
Level III, retrospective comparative study.

Focal cartilage defects can be treated by osteochondral autologous transplantation (OAT). High congruence of the graft with the surrounding cartilage structure is essential for a good clinical outcome, but can not always be achieved. We recently established a method to measure dissipated energy (DE) as a friction parameter in knee joints. We now investigated how autograft harvesting and implant positioning affect the DE during knee motion. Six sheep knee joints were cyclically motioned under 400 N axial load. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. Several experimental conditions were tested: first, the DE was measured after approach had been performed (\"native\"). Subsequently, a cylinder was removed from the medial femur condyles and a donor cylinder was inserted from an unloaded site in four different transplant positions: even, 1 mm deeper, 1 mm higher, and flush without cartilage (defect). No significant changes in friction were observed between the native knee and an even or deep OAT positioning. We, however, found a small but significant increase in DE between the \"native\" and \"1 mm high\" formations (ΔDE compared with native = 14 mJ/cycle; P = .004 after data normalization) and a large increase in defect situation (ΔDE compared with native = 119 mJ/cycle; P = .001). Considering the long-term therapeutic aim that is pursued when performing OAT, elevated graft positioning should clearly be avoided. From a biomechanical point of view, donor site morbidity after cylinder harvest can be neglected.

Dorsiflexion closing wedge metatarsal osteotomy (DCWMO) has been considered the traditional treatment of Freiberg disease. Several case reports presented osteochondral autologous transplantation (OAT) as an alternative treatment.
The purpose was to compare the results of DCWMO versus OAT for the treatment of Freiberg infraction in an athletic population. It was hypothesized that OAT was superior to DCWMO regarding functional outcomes, pain, and the time that the athletes returned to training and to previous sport level.
Randomized controlled trial; Level of evidence, 2.
Between 2008 and 2013, 27 consecutive patients with Freiberg disease were randomly assigned to either the DCWMO group (14 patients) or the OAT group (13 patients). The primary outcomes collected were as follows: postoperative complications, range of motion of the metatarsophalangeal joint, length of the metatarsal, function of the foot (measured with the American Orthopaedic Foot and Ankle Society-lesser metatarsophalangeal-interphalangeal [AOFAS-LMI] score), and pain (assessed with the visual analog scale-foot and ankle score).
Mean follow-up was 46 months (range, 36-60 months). The mean ± SD AOFAS-LMI score in the DCWMO group was 63.4 ± 14.4 preoperatively, 81.8 ± 6.6 at 1 year postoperatively, and 84.4 ± 5.6 at 3 years postoperatively, while in the OAT group, it was 62.8 ± 14, 89.9 ± 7.1, and 92 ± 6.9, respectively (P < .001). The differences in the AOFAS-LMI scores favoring the OAT group at 1 and 3 years reached statistical but not clinical significance. The mean visual analog scale-foot and ankle score was improved significantly from 48.1 ± 11.5 to 91.8 ± 9.5 in the DCWMO group and from 49.9 ± 10.9 to 95.4 ± 4.4 in the OAT group. There was a shortening of the metatarsals by a mean 1.9 ± 0.5 mm in the DCWMO group, as opposed to a metatarsal lengthening of 0.2 ± 0.1 mm in the OAT group. In the OAT group, patients were able to start training at 6 ± 1 weeks (P < .001) and return to full sport action at 10 ± 2.5 weeks (P < .05), while in the DCWMO group, the time was 8 ± 1.5 and 13 ± 2.5 weeks, respectively.
The authors concluded that OAT is equal to DCWMO. Acceptable clinical results were reported, as well as very low morbidity and early return to sport activities. That makes the OAT procedure a safe, effective, and optimal treatment for an athletic population experiencing Freiberg infraction.