Mosaicplasty with autogenous talar autograft for osteochondral lesions of the talus after failed primary arthroscopic management: a prospective study with a 4-year follow-up

Cartilage repair techniques of the talus: An update

Symptomatic chondral or osteochondral defects of the talus reduce the quality of life of many patients. Although their pathomechanism is well understood, it is well known that different aetiologic factors play a role in their origin. Additionally, it is well recognised that the talar articular cartilage strongly differs from that in the knee. Despite this fact, many recommendations for the management of talar cartilage defects are based on approaches that were developed for the knee. Conservative treatment seems to work best in paediatric and adolescent patients with osteochondritis dissecans. However, depending on the size of the lesions, surgical approaches are necessary to treat many of these defects. Bone marrow stimulation techniques may achieve good results in small lesions. Large lesions may be treated by open procedures such as osteochondral autograft transfer or allograft transplantation. Autologous chondrocyte transplantation, as a restorative procedure, is well investigated in the knee and has been applied in the talus with increasing popularity and promising results but the evidence to date is poor. The goals of the current article are to summarise the different options for treating chondral and osteochondral defects of the talus and review the available literature.

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.

Bony periosteum-covered iliac crest plug transplantation for severe osteochondral lesions of the talus: a modified mosaicplasty procedure

PURPOSE

This study reports first evidence of a modified procedure for osteochondral autologous transplantation where bony periosteum-covered plugs are harvested at the iliac crest and transplanted into the talar osteochondral lesion.

METHODS

Thirteen out of 14 patients, average age 39.6 (SD 14.4) years, were followed clinically and radiographically for a median of 25 (24-28) months (minimal follow-up, 24 months).

RESULTS

For these 13 patients, the American Orthopaedic Foot and Ankle Society hindfoot score increased from 47 (SD 11) points pre-operatively, to 81 (SD 14) points postoperatively (p < 0.0001). The average pain score decreased from 6.6 (SD 1.3) points pre-operatively, to 1.4 (SD 1.9) points postoperatively (p < 0.0001). Seven patients returned to sports activity. Radiographically good plug osteointegration was observed in nine out of 11 ankles. Follow-up arthroscopy showed fibrous cartilage in four ankles, periosteum hypertrophy in five ankles, and partial or total missing of coverage of the bone in three ankles. Three revision surgeries had to be performed.

CONCLUSIONS

This modified mosaicplasty might be recommended for severe and recurrent osteochondral lesions of the talus and may lead to restoration of the subchondral bone stock, formation of fibro-cartilage, and stable joint function.

LEVEL OF EVIDENCE

IV.

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

PURPOSE

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

METHODS

Forty-four patients with cartilage defects of the knee were treated with matrix-based autologous chondrocyte implantation (Novocart3D). All patients were assessed preoperatively and after a period of 24 months with the University of California Los Angeles (UCLA) Activity score. The return to physical activities or sports after matrix-based autologous chondrocyte implantation was documented. Patients were evaluated using the International Knee Documentation Committee Knee Examination Form and visual analogue scale for pain after 6, 12 and 24 months.

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level IV.

An anterior ankle arthroscopic technique for retrograde osteochondral autograft transplantation of posteromedial and central talar dome cartilage defects

PURPOSE

The purpose of this study was to present an arthroscopic technique for the treatment for posteromedial and central cartilage defects of the talus using anterior arthroscopic portals and without performing a medial malleolar osteotomy.

METHODS

Nine fresh cadavers were dissected. Autografts were implanted under arthroscopy using a retrograde osteochondral transplantation system, and their position was estimated using specific angular calibrators and later confirmed by software analysis of two photographs of the disarticulated ankle joint.

RESULTS

In eight cases, the congruence between the surrounding articular cartilage and the cartilage of the graft was high, with differences measuring <1 mm. There were no iatrogenic cartilage lesions of the tibial plafond and no fractures of the talus. All the autografts remained stable during full range of motion cycles of the ankle joint. One failure was reported.

CONCLUSION

This cadaveric study showed that the retrograde osteochondral autograft transplantation technique in the talus is feasible. It can be used to restore the posteromedial and central talar articular surfaces using conventional ankle arthroscopic instrumentation and anterior arthroscopic portals without resorting to a medial malleolar osteotomy. Further clinical and biomechanical studies are required to prove the efficacy of this technique and its reproducibility in routine clinical practice.

Arthroscopic autologous chondrocyte implantation in the ankle joint

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

IV, retrospective case series.

[Malleolar osteotomy--osteotomy as approach]

Both arthroscopic and open surgical techniques may be used for treatment of osteochondral lesions of the ankle joint. Osteotomy around the ankle joint is a well established technique to extend the approach in cases where the osteochondral lesions are located more posteriorly. Medial, oblique, monoplanar malleolar osteotomy should be used in patients with lesions of the medial talus shoulder. The posterolateral ostechondral lesions are less frequent and in such cases distal fibular osteotomy is recommended. In this study the indications for different forms of osteotomy are discussed and the surgical techniques are described.

Feet injuries in rock climbers

While injuries of the upper extremity are widely discussed in rock climbers, reports about the lower extremity are rare. Nevertheless almost 50 percent of acute injuries involve the leg and feet. Acute injuries are either caused by ground falls or rock hit trauma during a fall. Most frequently strains, contusions and fractures of the calcaneus and talus. More rare injuries, as e.g., osteochondral lesions of the talus demand a highly specialized care and case presentations with combined iliac crest graft and matrix associated autologous chondrocyte transplantation are given in this review. The chronic use of tight climbing shoes leads to overstrain injuries also. As the tight fit of the shoes changes the biomechanics of the foot an increased stress load is applied to the fore-foot. Thus chronic conditions as subungual hematoma, callosity and pain resolve. Also a high incidence of hallux valgus and hallux rigidus is described.

One-step bone marrow-derived cell transplantation in talarosteochondral lesions: mid-term results

PURPOSE

to verify the capability of scaffold-supported bone marrow-derived cells to be used in the repair of osteochondral lesions of the talus.

METHODS

using a device to concentrate bone marrow-derived cells, a scaffold (collagen powder or hyaluronic acid membrane) for cell support and platelet gel, a one-step arthroscopic technique was developed for cartilage repair. In a prospective clinical study, we investigated the ability of this technique to repair talar osteochondral lesions in 64 patients. The mean follow-up was 53 months. Clinical results were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) scale score. We also considered the influence of scaffold type, lesion area, previous surgery, and lesion depth.

RESULTS

the mean preoperative AOFAS scale score was 65.2 ± 13.9. The clinical results peaked at 24 months, before declining gradually to settle at a score of around 80 at the maximum follow-up of 72 months.

CONCLUSIONS

the use of bone marrow-derived cells supported by scaffolds to repair osteochondral lesions of the talus resulted in significant clinical improvement, which was maintained over time.

LEVEL OF EVIDENCE

level IV, therapeutic case series.

A systematic review on the reporting of outcome data in studies on autologous osteochondral transplantation for the treatment of osteochondral lesions of the talus

PURPOSE

The purpose of this study was to systematically review studies on autologous osteochondral transplantation (AOT) for osteochondral lesions (OCLs) of the talus and descriptively analyze the outcome data reported to determine whether it is consistent from one study to another and able to be pooled for systematic review.

METHODS

A systematic electronic search was performed using the MEDLINE and EMBASE databases. Studies that were published between January 1966 and June 2011 were included in the review. Only studies that reported data specifically on AOT for treatment of OCLs of the talus and written in English were included in this review. A predefined data sheet with 36 variables was created, and it was determined whether or not each of those variables were reported or not reported. The 36 variables were then grouped into 6 categories, and the categorical means were reported.

RESULTS

A total of 20 studies were included in this systematic review. The categories of general demographics and study design were generally well reported (each more than 80% of studies). Patient-reported outcomes and clinical variables were reported less in 73% and 67% of studies, respectively. The least-reported categories were patient history (45%) and imaging data (49%).

CONCLUSIONS

Inconsistencies and an underreporting of data were apparent between studies, such that pooling was deemed not possible. An effort must be made by investigators to ensure that there is adequate reporting of data in studies of AOT treatment for OCLs of the talus.

Searching for Hidden, Painful Osteochondral Lesions of the Ankle in Patients with Chronic Lower Limb Pain - Two Case Reports -

It is easy to overlook osteochondral lesions (OCLs) of the ankle in patients with chronic lower limb pain, such as complex regional pain syndrome (CRPS) or thromboangiitis obliterans (TAO, Buerger's disease). A 57-year-old woman diagnosed with type 1 CRPS, and a 58-year-old man, diagnosed with TAO, complained of tactile and cold allodynia in their lower legs. After neurolytic lumbar sympathethic ganglion block and titration of medications for neuropathic pain, each subject could walk without the aid of crutches. However, they both complained of constant pain on the left ankle during walking. Focal tenderness was noted; subsequent imaging studies revealed OCLs of her talus and his distal tibia, respectively. Immediately after percutaneous osteoplasties, the patients could walk without ankle pain. It is important to consider the presence of a hidden OCL in chronic pain patients that develop weight-bearing pain and complain of localized tenderness on the ankle.

Osteochondral lesions of the talus: size, age, and predictors of outcomes

In this article, our research on osteochondral lesions of the talus (OLTs) is summarized, the orthopedic literature is reviewed, and the direction of future research and treatment trends are discussed. Our research has explored the role of lesion size, significance of marrow edema, relationship of patient age, importance of lesion containment, and role of a stable cartilage lesion cap in the prognosis and outcomes of these lesions. We have identified smaller sized lesions, younger patients and contained lesions as independent predictors of success for the operative treatment of OLTs. Our data should facilitate the development of a more comprehensive treatment algorithm to more accurately predict success in operative management of these lesions.

Outcome of arthroscopic debridement and microfracture as the primary treatment for osteochondral lesions of the talar dome

PURPOSE

The purpose of this systematic review was to determine patient outcomes after arthroscopic debridement and microfracture for osteochondral lesions (OCLs) of the talar dome.

METHODS

Infotrieve-PubMed/MEDLINE and Google Scholar were systematically searched for the following terms: microfracture AND ankle OR talus. In addition, we hand-searched common American and European orthopaedic and podiatric surgical journals for relevant manuscripts. Articles considered for inclusion were published in peer-reviewed journals, used the American Orthopaedic Foot & Ankle Society hindfoot scoring system for outcome measurement, and involved arthroscopic debridement and microfracture for OCL of the talar dome.

RESULTS

We identified 29 potentially relevant publications, of which 7 met our inclusion criteria. A total of 295 patients (299 ankles) were included in this study. The weighted mean postoperative American Orthopaedic Foot & Ankle Society hindfoot score was 86.8 points, translating to good to excellent outcomes in 80.2% of patients.

CONCLUSIONS

Many techniques exist for the treatment of OCLs of the talar dome. Good to excellent results can be consistently reached in greater than 80% of patients with arthroscopic debridement and microfracture. However, additional prospective trials should be undertaken to determine differences in outcome between techniques, size and location of the OCL, and other patient quality factors, such as cost and time to return to work.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III, and IV studies.

Factors associated with the clinical outcomes of the osteochondral autograft transfer system in osteochondral lesions of the talus: second-look arthroscopic evaluation

BACKGROUND

Identifying factors associated with the clinical outcomes of the osteochondral autograft transfer system would be helpful for treating patients with an osteochondral lesion of the talus.

PURPOSE

To investigate the clinical and second-look arthroscopic results of the osteochondral autograft transfer system and to identify the prognostic factors associated with this procedure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors retrospectively evaluated 52 ankles that underwent osteochondral autograft transfer for a medial osteochondral lesion of the talus. Second-look arthroscopies were performed at a mean of 13.1 months postoperatively. Clinical outcomes were evaluated according to a visual analog scale (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) score, and the Tegner activity scale. Statistical analyses were performed to identify various prognostic factors associated with the clinical outcomes.

RESULTS

The mean VAS, AOFAS, and Tegner activity scale scores were all significantly improved from 6.9 ± 0.9 to 3.3 ± 1.4 (VAS), from 67.4 ± 4.9 to 82.6 ± 7.8 (AOFAS), and from 3.0 ± 0.8 to 3.9 ± 0.9 (Tegner; P < .05). Regarding overall patient satisfaction with the operation, 49 (95%) patients reported good to excellent results. Prognostic factors including the patient's age, sex, body mass index, duration of symptoms, defect size and depth, location of osteochondral lesion of the talus, and the existence of a subchondral cyst did not significantly influence clinical outcomes (P > .05), except for body mass index on the Tegner activity scale score (P = .021). Significant differences were observed among clinical outcomes for second-look arthroscopy according to the presence of soft tissue impingement and uncovered areas around the graft (P < .05). The VAS and AOFAS score at the last follow-up were significantly worse when the articular surface of the tibial plafond at the malleolar osteotomy site was uneven (P = .031 and .012, respectively).

CONCLUSION

This study showed that the articular surface of the tibial plafond at the malleolar osteotomy site, soft tissue impingement, and uncovered areas around the graft were important factors affecting the clinical outcomes, as observed through second-look arthroscopy. Therefore, surgeons should restore the articular surface accurately after the osteotomy, and more caution should be taken to avoid soft tissue impingement and uncovered areas around the graft when performing osteochondral autograft transfer.

Platelet-rich plasma or hyaluronate in the management of osteochondral lesions of the talus

BACKGROUND

Nonoperative options for osteochondral lesions (OCLs) of the talar dome are limited, and currently, there is a lack of scientific evidence to guide management.

PURPOSE

To evaluate the short-term efficacy and safety of platelet-rich plasma (PRP) compared with hyaluronic acid (HA) in reducing pain and disability caused by OCLs of the ankle.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Thirty-two patients aged 18 to 60 years were allocated to a treatment by intra-articular injections of either HA (group 1) or PRP (plasma rich in growth factors [PRGF] technique, group 2) for OCLs of the talus. Thirty OCLs, 15 per arm, received 3 consecutive intra-articular therapeutic injections and were followed for 28 weeks. The efficacy of the injections in reducing pain and improving function was assessed at each visit using the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale (AHFS); a visual analog scale (VAS) for pain, stiffness, and function; and the subjective global function score.

RESULTS

The majority of patients were men (n = 23; 79%). The AHFS score improved from 66 and 68 to 78 and 92 in groups 1 and 2, respectively, from baseline to week 28 (P < .0001), favoring PRP (P < .05). Mean VAS scores (1 = asymptomatic, 10 = severe symptoms) decreased for pain (group 1: 5.6 to 3.1; group 2: 4.1 to 0.9), stiffness (group 1: 5.1 to 2.9; group 2: 5.0 to 0.8), and function (group 1: 5.8 to 3.5; group 2: 4.7 to 0.8) from baseline to week 28 (P < .0001), favoring PRP (P < .05 for stiffness, P < .01 for function, P > .05 for pain). Subjective global function scores, reported on a scale from 0 to 100 (with 100 representing healthy, preinjury function) improved from 56 and 58 at baseline to 73 and 91 by week 28 for groups 1 and 2, respectively (P < .01 in favor of PRP).

CONCLUSION

Osteochondral lesions of the ankle treated with intra-articular injections of PRP and HA resulted in a decrease in pain scores and an increase in function for at least 6 months, with minimal adverse events. Platelet-rich plasma treatment led to a significantly better outcome than HA.

Arthroscopic autologous chondrocyte implantation in osteochondral lesions of the talus: mid-term T2-mapping MRI evaluation

PURPOSE

Autologous chondrocyte implantation (ACI) in the ankle has become an established procedure to treat osteochondral lesions. However, a non-invasive method able to provide information on the nature of the repair tissue is needed. Recently, MRI T2 mapping was identified as a method capable of qualitatively characterizing articular cartilage. The aim of this study was to evaluate the mid-term results of a series of patients arthroscopically treated by ACI and investigate the nature of the repair tissue by MRI T2 mapping.

METHODS

Twenty patients, aged 35 ± 8 years, with an osteochondral lesion of the talus, underwent ACI and were evaluated at 5 ± 1 years' follow-up clinically (AOFAS score) and by the MRI T2-mapping sequence. MRI images were acquired using a protocol proposed by the International Cartilage Repair Society, evaluated by the MOCART score and completed by the T2-mapping sequence. Healthy volunteers, mean age 29 ± 6 years, were enrolled, and their T2 map values were used as a control. Their MRI results were then correlated with the clinical score.

RESULTS

The AOFAS score increased from 59 ± 16 pre-operatively to 84 ± 18 at follow-up (P < 0.0005). Patients with more than 4 years' follow-up were found to have the most satisfactory results. On the basis of the controls, healthy hyaline cartilage tissue showed a T2 map value of 35-45 ms. A mean T2 map value compatible with normal hyaline cartilage was found in all the cases treated, covering a mean percentage of 69% ± 22 of the repaired lesion area.

CONCLUSIONS

ACI was able to provide durable results that improved over time. Because of its ability to detect cartilage quality, the MRI T2-mapping sequence integrated with the Mocart score is a valid, non-invasive technique in evaluating the nature of the repair tissue in the ankle joint.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

The clinical outcomes of mosaicplasty in the treatment of osteochondritis dissecans of the distal humeral capitellum of young athletes

BACKGROUND

The purpose of this study was to evaluate the clinical outcomes of mosaicplasty in the treatment of osteochondritis dissecans of the distal humeral capitellum.

MATERIALS AND METHODS

Between 2003 and 2007, 10 patients (6 female and 4 male patients), with a mean age at surgery of 18 years (range, 13 to 27 years), with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. The surgical technique involves transplanting small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyle at the level of the patellofemoral joint to the defect of the capitellum. At a mean follow-up of 30 months, all elbows were assessed with the Mayo Elbow Performance Score and a modified functional elbow score (Constant).

RESULTS

Postoperative radiographs and control magnetic resonance imaging/computed tomography images showed incorporation of the subchondral cortex in all patients. All but 2 patients were completely pain free after surgery. Of the patients, 8 (80%) had no reduction in range of motion. By use of the Mayo Elbow Performance Score, the injured elbow had a preoperative mean score of 71 points (range, 55 to 85 points) and increased significantly to a mean score of 93.5 points (range, 85 to 100 points) postoperatively (P = .0005, paired t test). The nonoperative elbows had a mean score of 100 points, whereas the operated elbows had a mean score of 93.5 points. The functional elbow score showed a mean difference of 7.5 points between the operated and nonoperative elbows. No infection or neurologic deficit developed after surgery in any case.

CONCLUSIONS

Autologous osteochondral mosaicplasty for advanced lesions of capitellar osteochondritis dissecans can provide satisfactory clinical and radiographic results.

Osteochondral transplantation of the talus: long-term clinical and magnetic resonance imaging evaluation

BACKGROUND

Osteochondral lesions of the ankle are a common injury after ankle sprains, especially in young and active patients. The Osteochondral Autograft Transfer System (OATS) is the only 1-step surgical technique designed to replace the entire osteochondral unit.

PURPOSE

This study was conducted to evaluate the long-term clinical and radiographic outcomes of the OATS procedure for the talus and compare the results of patients who have had prior surgical interventions with patients for whom OATS represents the primary surgical treatment.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors retrospectively analyzed 26 talus OATS procedures (25 patients) with an average follow-up of 84 months (range, 53-124 months); 9 patients had OATS as a second surgical intervention. The patients completed the American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner scores plus the visual analog scale (VAS) preoperatively and at follow-up. Magnetic resonance imaging examinations were conducted on a 1.5-T whole-body magnet that assessed transplant congruency, adjacent surface of the talus, the corresponding distal tibia, and joint effusion.

RESULTS

The authors found significant increases for the AOFAS score (50 to 78 points, P < .01) and the Tegner score (3.1 to 3.7, P < .05) and a significant decrease for the VAS (7.8 to 1.5, P < .01) from preoperative to postoperative. Patients with normal integration or minor incongruity of the transplant on magnetic resonance imaging (81%) had significantly better AOFAS scores (P = .03). Other magnetic resonance imaging criteria did not predict clinical results. Patients for whom OATS represented a second procedure had significantly worse clinical AOFAS and Tegner scores plus a higher VAS.

CONCLUSION

Long-term clinical and magnetic resonance imaging results after osteochondral transplantation are good and patients significantly benefit from this surgery. Magnetic resonance imaging should not be a routine control but appears to be indicated when clinical symptoms persist after osteochondral transplantation.

Functional outcome of matrix-associated autologous chondrocyte implantation in the ankle

BACKGROUND

The technique of Matrix-associated autologous chondrocyte implantation (MACI) is well established with satisfactory outcomes up to 5 years in the knee. Fewer series describe the outcomes of this technique in the ankle. We present the functional outcomes of the technique for a single surgeon series in a general hospital setting.

MATERIALS AND METHODS

Twenty-seven patients, mean age 41, were reviewed at 3.7 (range, 1 to 5) years. Patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale, Tegener activity score and University of California lower extremity activity scale. MRI findings were also reviewed.

RESULTS

While most patients report a significant improvement in symptoms with full return to activities of daily living, 36% of those under 40 and 78% of those over 40 reported restricted recreational activity. Of the patients under 40 years of age, 86% were able to run compared with 23% of those over 40. Of patients over 40, 64% continued to have moderate or severe pain.

CONCLUSION

Careful preoperative counseling is required for patients of all ages regarding likely outcomes. In patients over 40, the procedure is unlikely to give good pain relief and alternative options should be considered.

Identification of molecular markers for articular cartilage

OBJECTIVE

The aim of the current study was to identify molecular markers for articular cartilage (AC) that can be used as tools for the quality control of tissue engineered (TE) cartilage.

DESIGN

A genome-wide expression analysis was performed using RNA isolated from articular and growth plate (GP) cartilage, both extracted from the knee joints of 6 weeks old minipigs. After confirming the specific expression for selected genes by RT-PCR, these were used as molecular markers for the quality control of TE cartilage.

RESULTS

Albeit several known chondrocyte markers were expressed to a similar extent in articular and GP cartilage, our genome-wide expression analysis led us to identify genes being selectively expressed in either GP or articular chondrocytes. These findings led us to perform a RT-PCR expression analysis for the corresponding genes to demonstrate the absence of GP-specific markers in TE cartilage, while common or AC markers were expressed.

CONCLUSIONS

Taken together, these results provide important novel insights into chondrocyte biology in general and AC in particular. In addition, it is reasonable to speculate, that some of the identified genes play distinct roles in the regulation of articular chondrocyte differentiation and/or function, thereby raising the possibility that they may serve as targets for non-operative therapies of osteoarthritis (OA).

Retrograde cancellous bone plug transplantation for the treatment of advanced osteochondral lesions with large subchondral lesions of the ankle

BACKGROUND

The surgical results have been reported as poor for advanced osteochondral lesions of the ankle with large subchondral lesions including subchondral cyst.

HYPOTHESIS

Transplanting an autologous cancellous bone plug from the pelvis to the lesions retrogradely may bring good clinical results for the treatment of advanced osteochondral lesions with large subchondral lesions including subchondral cyst of the ankle.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Twenty-five osteochondral lesion patients who had large subchondral lesions of the ankle (diameter > or =10 mm on magnetic resonance imaging) met the criteria of this study. Fourteen of those patients were treated with arthroscopic antegrade drilling (group AD), and the other 11 patients were treated with arthroscopic retrograde cancellous bone plug transplantation from the iliac crest (group RC). The clinical results in conjunction with the American Orthopaedic Foot and Ankle Society (AOFAS) scores, diameters of the subchondral lesions on magnetic resonance imaging, and the regenerative cartilage in second-look arthroscopy using International Cartilage Repair Society (ICRS) visual repair assessment score were evaluated.

RESULTS

The mean AOFAS score at 2 years after surgery was 82.2 +/- 7.2 in group AD and 95.8 +/- 4.6 in group RC (P < .0001). Diameter of the subchondral lesion was almost unchanged in 11 cases (78.5%) in group AD, compared with disappearance in 7 cases (73.8%) and decreased lesion size in 4 cases (36.4%) in group RC. The mean ICRS score at second-look arthroscopy was 5.1 +/- 1.9 in group AD and 10.5 +/- 0.8 in group RC (P = .0001).

CONCLUSION

The authors recommend arthroscopic retrograde autologous cancellous bone plug transplantation from the iliac crest as a surgical procedure for the treatment of advanced osteochondral lesions with large subchondral lesions of the ankle.

Fresh osteochondral allografting for osteochondral lesions of the talus

BACKGROUND

Osteochondral lesions of the talus (OLT) are relatively common sequelae of traumatic injuries involving the talus. We report on clinical outcomes of osteochondral allografting (OCA) of the talus for refractory, symptomatic OLT.

MATERIALS AND METHODS

OCA was performed in 12 ankles in 11 patients with OLT. All involved partial, unipolar grafts of the talar dome, implanted through an anterior approach without osteotomy, under temporary distraction. Clinical evaluation was performed utilizing the Olerud-Molander Ankle Score (OMAS). Subjective outcome measures included patient questionnaires evaluating pain, function, and satisfaction. Eleven patients (seven males, four females) had a mean age of 35.5 (range, 26 to 57) years. One patient had bilateral involvement. Six OLT affected the medial, six the lateral talar dome. Patients had an average of 1.8 previous surgeries (range, 1 to 5). Mean followup was 38 (range, 24 to 107) months.

RESULTS

Mean OMAS improved from 28 to 71 points (p < 0.05). Three had further surgery; overall graft survival rate was 10/12. Of surviving grafts, 30% recorded excellent (OMAS: 100 to 91 points), 20% good (OMAS: 90 to 61 points), 30% fair (OMAS: 60 to 31 points), and 20% poor (OMAS: 30 to 0 points) outcomes. All non-failing patients completed questionnaires; 90% were satisfied, 80% reported reduced pain, and 60% improved function.

CONCLUSION

OCA achieved good to excellent results in five of 12 patients, resulting in significant improvement in function and pain with good patient satisfaction. All but one patient avoided arthrodesis. Partial talus OCA is a reasonable treatment option for appropriately selected patients with unipolar OLT.

Treatment of osteochondral lesions of the talus: a systematic review

The aim of this study was to summarize all eligible studies to compare the effectiveness of treatment strategies for osteochondral defects (OCD) of the talus. Electronic databases from January 1966 to December 2006 were systematically screened. The proportion of the patient population treated successfully was noted, and percentages were calculated. For each treatment strategy, study size weighted success rates were calculated. Fifty-two studies described the results of 65 treatment groups of treatment strategies for OCD of the talus. One randomized clinical trial was identified. Seven studies described the results of non-operative treatment, 4 of excision, 13 of excision and curettage, 18 of excision, curettage and bone marrow stimulation (BMS), 4 of an autogenous bone graft, 2 of transmalleolar drilling (TMD), 9 of osteochondral transplantation (OATS), 4 of autologous chondrocyte implantation (ACI), 3 of retrograde drilling and 1 of fixation. OATS, BMS and ACI scored success rates of 87, 85 and 76%, respectively. Retrograde drilling and fixation scored 88 and 89%, respectively. Together with the newer techniques OATS and ACI, BMS was identified as an effective treatment strategy for OCD of the talus. Because of the relatively high cost of ACI and the knee morbidity seen in OATS, we conclude that BMS is the treatment of choice for primary osteochondral talar lesions. However, due to great diversity in the articles and variability in treatment results, no definitive conclusions can be drawn. Further sufficiently powered, randomized clinical trials with uniform methodology and validated outcome measures should be initiated to compare the outcome of surgical strategies for OCD of the talus.

A comparison of open versus arthroscopic harvesting of osteochondral autografts

Osteochondral autograft transfer is a technique for treatment of traumatic and degenerative cartilage lesions. A graft in which the cartilage cap is oriented perpendicular to the long axis of the graft is ideal because it can both restore the cartilage tidemark and minimize articular step-off at the recipient site. This study determines if osteochondral harvest technique (arthroscopic versus mini-open) or donor site location affects suitable graft harvest. One hundred and twenty eight osteochondral grafts were harvested in 16 cadaver knees utilizing a 7 mm OATS chisel from four donor sites: lateral supracondylar ridge, lateral femoral condyle, lateral intercondylar notch and medial femoral condyle. Mini-open and arthroscopic harvesting techniques were equally employed. Radiographic methods were used to analyze graft perpendicularity. Statistical analysis comparing graft suitability based on technique and donor site location was performed. There were no statistically significant differences (p>0.05) in graft suitability regardless of the technique used or donor site location. 69% of arthroscopic and 56% of mini-open graft harvest were considered suitable, possessing a cartilage cap and graft axis angle that would create less than 1 mm of articular incongruity. Incongruity results when the angle between the subchondral bone plug long axis and cartilage interface is greater than 74 degrees . There is no difference in the quality of osteochondral grafts harvested from the knee regardless of technique or donor site used. Osteochondral graft diameter should be kept at or less than 7 mm because of the high percentage of unacceptable grafts with increasing chisel sizes.

One-step bone marrow-derived cell transplantation in talar osteochondral lesions

The ideal treatment of osteochondral lesions is debatable. Although autologous chondrocyte implantation provides pain relief, the need for two operations and high costs has prompted a search for alternatives. Bone marrow-derived cells may represent the future in osteochondral repair. Using a device to concentrate bone marrow-derived cells and collagen powder or hyaluronic acid membrane as scaffolds for cell support and platelet gel, a one-step arthroscopic technique was developed for cartilage repair. We performed an in vitro preclinical study to verify the capability of bone marrow-derived cells to differentiate into chondrogenic and osteogenic lineages and to be supported onto scaffolds. In a prospective clinical study, we investigated the ability of this technique to repair talar osteochondral lesions in 48 patients. Minimum followup was 24 months (mean, 29 months; range, 24-35 months). Clinical results were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score and the influence of scaffold type, lesion area, previous surgeries, and lesion depth was considered. MRI and histologic evaluation were performed. The AOFAS score improved from 64.4 +/- 14.5 to 91.4 +/- 7.7. Histologic evaluation showed regenerated tissue in various degrees of remodeling although none showed entirely hyaline cartilage. These data suggest the one-step technique is an alternative for cartilage repair, permitting improved functional scores and overcoming the drawbacks of previous techniques.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Osteochondral transfer using a transmalleolar approach for arthroscopic management of talus posteromedial lesions

Characterizing osteochondral lesions of the talus has enabled the strategies of surgical management to be better specified. The main technical problem is one of access for arthroscopy instruments to posteromedial lesions. A range of techniques and approaches has been described in ankle arthroscopy in general, and a transmalleolar approach provides reliable and efficient access in these cases. It is frequently used for transchondral drilling, but also enables satisfactory implant positioning in autologous osteochondral mosaicplasty procedures. We report our technique and results on five cases with a minimum 1.2 years' follow-up.

Knee-to-ankle mosaicplasty for the treatment of osteochondral lesions of the ankle joint

BACKGROUND

Osteochondral lesions are frequently seen in athletes after ankle injuries. At this time, osteochondral autologous transplantation (OATS, mosaicplasty) is the only surgical treatment that replaces the entire osteochondral unit in symptomatic lesions.

PURPOSE

To evaluate the clinical and radiological midterm to long-term outcome of ankles treated with knee-to-ankle mosaicplasty.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Clinical evaluation consisted of patient satisfaction, pain evaluation (visual analog scale [VAS]), American Orthopaedic Foot and Ankle Society (AOFAS) ankle score, sports activity score, range of motion, the radiological evaluation of magnetic resonance imaging (MRI), and single photon emission computed tomography-computed tomography (SPECT-CT) analysis of both the ankle and the knee joint.

RESULTS

Twelve of 21 patients (mean age, 43 years; male, 8; female, 4) were available for latest follow-up (mean, 72 months). At follow-up, patients reported a satisfaction rate of good to excellent in 92% (n = 11) and poor in 8% (n = 1). The average VAS pain score was 3.9 (preoperative, 5.9; P = .02), AOFAS ankle score significantly increased from 45.9 to 80.2 points (P < .0001), sports activity score remained significantly decreased with 1.25 (preinjury level, 2.3; P = .035), and ankle dorsiflexion was significantly reduced (P = .003). Knee pain was reported in 6 patients (50%). Radiologically, recurrent lesions were found in 10 of 10 cases (100%) and some degree of cartilage degeneration and discontinuity of the subchondral bone plate in 100%.

CONCLUSION

Indications for mosaicplasty with a plug transfer from the knee to the talus must be considered carefully, as at midterm, moderate outcome and considerable donor-site morbidity may be found.

Cartilage transplantation techniques for talar cartilage lesions

Talar articular cartilage is known to differ significantly from knee cartilage. Even so, recommendations for the treatment of talar cartilage lesions have been based on strategies for the knee. Arthroscopic management of osteochondral lesions of the talus is well documented. Results have been favorable with reparative techniques such as débridement with curettage and débridement with drilling, whether undertaken via early open techniques or more recent arthroscopic procedures. Salvage of failed reparative techniques is controversial. Early efforts to salvage failed débridement focused on osteochondral allografts and autografts that used the knee as a donor site. Results of these restorative techniques have been favorable, but concerns have been raised regarding knee donor site morbidity, the use of malleolar osteotomy, and incomplete restoration of the talar articular surface. More recent restorative techniques developed for the knee have been adapted for the ankle, such as autologous chondrocyte implantation and matrix-induced autologous chondrocyte implantation.

A review of osteochondral lesions of the talus

This article provides an in-depth overview of the most current information.

Treatment of osteochondritis dissecans of the ankle with hyaluronic acid injections: a prospective study

BACKGROUND

No studies have evaluated the efficacy of hyaluronic acid (HA) in reducing pain caused by osteochondritis dissecans (OCD) of the ankle. We report our initial results with this treatment.

MATERIALS AND METHODS

Fifteen subjects aged 18 to 60 treated for OCD of the talus were followed for 26 weeks, in a pre- and post-treatment repeated measurements design, after receiving three weekly injections of intra-articular HA. The efficacy of HA injections in reducing pain and improving function was assessed at each visit and adverse events were recorded. Efficacy was evaluated by comparing scores determined using a Visual Analog Scale for pain, stiffness and function over time with baseline values. In addition, frequency of symptoms and global function over time were assessed using questionnaires and the AOFAS Ankle-Hindfoot Scale. Data analysis was made using ANCOVA models and paired t-tests. All statistical tests were based on an alpha level of 0.05.

RESULTS

The majority of subjects were male (60%) and had Grade 3 lesions (60%). Mean VAS scores, reported on a scale from 1 (e.g., no pain) to 10 (e.g., worst pain) decreased for pain (5.6 to 3.2), stiffness (5.1 to 2.9), and function (5.9 to 3.3) from baseline to week 26. Subjective global function scores, reported on a scale from 0 to 100 (with 100 representing healthy, pre-injury function), improved on average from 57.3 at baseline to 74.3 by week 26. All of these results were statistically significant, as was the decrease in frequency of pain reported by subjects at the end of the study.

CONCLUSION

OCD of the ankle treated with intra-articular injections of HA caused a decrease in pain scores and increase in global functioning over a short period of time (within 12 weeks) which then lasted for more than 6 months with minimal adverse events.

Treatment of osteochondral defects of the talus

This review article provides a current concepts overview of osteochondral defects of the talus, with special emphasis on treatment options, their indications and future developments. Osteochondral defects of the talar dome are mostly caused by a traumatic event. They may lead to deep ankle pain on weight-bearing, prolonged swelling, diminished range of motion and synovitis. Plain radiographs may disclose the lesion. For further diagnostic evaluation, computed tomography (CT) and magnetic resonance imaging (MRI) have demonstrated similar accuracy. Computed tomography is preferred for preoperative planning. Treatment options are diverse and up to the present there is no consensus. Based on the current literature, we present a treatment algorithm that is mainly guided by the size of the lesion. Asymptomatic or low-symptomatic lesions are treated nonoperatively. The primary surgical treatment of defects up to 15 mm in diameter consists of arthroscopic debridement and bone marrow stimulation. For large cystic talar lesions, retrograde drilling combined with a bone graft is an important alternative. In adolescents or in (sub)acute situations, in which the fragment is 15 mm or larger, fixation of the fragment is preferred. Osteochondral autograft transfer and autologous chondrocyte implantation (ACI), with or without a cancellous bone graft, are recommended for secondary cases as well as large lesions.

Arthroscopic treatment of chronic osteochondral lesions of the talus: long-term results

BACKGROUND

Osteochondral lesions of the talus are relatively uncommon but may be a cause of significant pain and disability in symptomatic patients.

HYPOTHESIS

Arthroscopic treatment of osteochondral lesions of the talus will result in good long-term clinical outcomes in the majority of patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Fifty patients with chronic osteochondral lesions of the talus underwent arthroscopic treatment. Average age was 32 years (range, 12-72 years). Average follow-up was 71 months (range, 24-152 months). Treatment consisted of either drilling of the osteochondral lesions of the talus in situ (n = 4), excision of the osteochondral lesions of the talus and abrasion arthroplasty (n = 6), or excision of the osteochondral lesions of the talus and drilling (n = 40). Preoperative and intraoperative staging of the osteochondral lesions of the talus was performed. Follow-up evaluation included 3 clinical rating systems: Alexander, modified Weber, and American Orthopaedic Foot and Ankle Society Ankle/Hindfoot scores.

RESULTS

There were 72% excellent/good, 20% fair, and 8% poor results on the Alexander scale. According to the modified Weber scale, there were 64% excellent/good, 30% fair, and 6% poor results. The average American Orthopaedic Foot and Ankle Society Ankle/Hindfoot score was 84 (range, 34-100). We found no correlation between plain radiographs, computed tomography, or magnetic resonance imaging staging and clinical results. However, there was significant correlation between arthroscopic stage and clinical outcome. Seventeen patients had been seen 5 years previously and evaluated using the same criteria; 35% demonstrated a deterioration in their result over time.

CONCLUSION

Arthroscopic treatment of chronic symptomatic osteochondral lesions of the talus results in good clinical outcomes in the majority of patients. However, pain and functional limitation may persist in some patients, especially those noted to have unstable osteochondral defects at the time of arthroscopy.

No mid-term difference in mosaicplasty in previously treated versus previously untreated patients with osteochondral lesions of the talus

INTRODUCTION

Osteochondral transplantations, albeit technically challenging, appear promising not only in knee joint lesions, but also in the treatment of talus lesions. We hypothesized that in patients suffering osteochondral lesions of the talus, favorable outcomes are obtained in patients undergoing primary mosaicplasty as compared to patients undergoing secondary mosaicplasty.

MATERIALS AND METHODS

Over a 3-year period (1998-2001), 14 patients (six male, eight female, median age 22 years) were treated with an autologous osteochondral transplantation of the talus. Eight patients were previously untreated (group I). Six patients had previous ankle procedures, such as microfracturing (group II). The median follow-up was 24 months and 100% complete at 12 months. The functional outcome was evaluated at least at 6 weeks, 12 weeks, and 1 year after surgery using pain on a visual analog scale (VAS) and sports activity was recorded at 1 year after surgery. In ten patients, magnetic resonance imaging (MRI) of the ankle was performed at 1 year after surgery (group I/II: 7/3).

RESULTS

Overall ankle pain was decreased from 6.9 +/- 2.1 to 4.0 +/- 2.8 postoperatively. The mean knee pain for the donor knee was 2.6 +/- 2.4. We found no significant difference between the primary mosaicplasty group and the secondary mosaicplasty group with regard to pain. MRI scans of ten patients showed a complete incorporation of the osteochondral cylinders at 1 year after surgery.

CONCLUSION

Favorable outcomes were obtained in patients undergoing primary mosaicplasty as compared to patients undergoing secondary mosaicplasty. We found no significant difference among patients with previous ankle surgery in contrast to those without, with a median 24-months follow-up.

Articular talar injuries in athletes: results of microfracture and autogenous bone graft

BACKGROUND

The treatment options of talar osteochondral lesions are numerous. Although studies show these treatments have been used with varying success, the ability to return to activity (RTA), including sports after treatment of talar dome injuries, have not been well documented.

HYPOTHESIS

A treatment plan that uses microfracture for Hepple stage 2 through 4 lesions and autogenous bone grafting for Hepple stage 5 lesions for athletes with articular lesions of the talus will produce a high rate of return to athletic activity.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores and RTA were assessed prospectively 2 to 8 years after surgery in high-demand (athletic) patients with articular injuries to the talar dome treated according to the above protocol over a 6-year period.

RESULTS

There were 26 microfracture procedures and 20 bone grafts to the talus. The AOFAS scores for both microfracture (pre-operative, 54.6; postoperative, 94.4) and bone graft (preoperative, 46.1; postoperative, 93.4) patients improved significantly. The RTA for the entire group was 17.0 +/- 5.3 weeks; for those undergoing microfracture, RTA was 15.1 +/- 4.0 weeks; and for bone grafting, it was 19.6 +/- 5.9 weeks. The RTA for the bone graft group was significantly slower than that of the microfracture group. Anterolateral lesions had significantly faster RTA and higher postoperative scores compared with other lesion locations. Arthroscopically treated lesions had similar postoperative AOFAS scores to those who had arthrotomy and did not have significantly faster RTA. Forty-four (96%) "excellent/good" AOFAS scores were achieved overall for talar lesions, with the same percentage of return to sport.

CONCLUSIONS

Talar bone grafting required a longer time to return to activity than microfracture in high-demand patients, but both groups had similar postoperative AOFAS scores. When applied to appropriate lesions, both techniques allow athletic patients to return to sports.

Importance of sports in cartilage regeneration after autologous chondrocyte implantation: a prospective study with a 3-year follow-up

BACKGROUND

There have been no data in the literature reporting the influence of sports on the outcome of autologous chondrocyte implantation in chondral defects of the knee.

HYPOTHESIS

Sports can improve the result of autologous chondrocyte implantation in postoperative follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Between 1997 and 2003, 118 patients with symptomatic isolated chondral lesions of the knee underwent autologous chondrocyte implantation. According to the sports activity level before the start of symptoms, patients were assigned to 2 groups: group II with no or rare sports involvement (1-3 times/month); group I with regular (1-3 times/week) or competitive sports (4-7 times/week). All patients underwent clinical and magnetic resonance imaging evaluation preoperative and 6, 18, and 36 months after autologous chondrocyte implantation.

RESULTS

Group I patients showed significantly better results (< .01) in the International Cartilage Repair Society and Cincinnati scores than group II patients. Preoperative evaluation revealed no correlation between the sports activity levels and the clinical scores (P > .05). However, from the sixth month on, correlation was statistically significant, increasing from 6 to 18 months, and from 18 to 36 months postoperatively.

CONCLUSION

Physical training improves long-term results after autologous chondrocyte implantation of the knee and should be carried out for at least 2 years after surgery.

Autologous chondrocyte implantation in chondral defects of the knee with a type I/III collagen membrane: a prospective study with a 3-year follow-up

PURPOSE

The clinical results after autologous chondrocyte implantation (ACI) with a collagen membrane using sequential objective patient evaluation (clinical examination and magnetic resonance imaging [MRI]) are inadequately reported. This prospective study was performed to determine the results after ACI at different time intervals over a period of 36 months.

METHODS

Between 2000 and 2002, 63 patients (mean age, 34 years) with full-thickness chondral lesions of the knee underwent an autologous chondrocyte implantation and were evaluated preoperatively and at 6, 18, and 36 months after surgery. The chondrocyte suspension within the defect was covered with a type I/III collagen membrane. Depending on the localization of the defects (femoral condyles, trochlea, and retropatellar), the patients were assigned to three different groups. Exclusion criteria were meniscal pathologies, axial malpositioning, and ligament instabilities. Baseline clinical scores (modified Cincinnati knee score and the International Cartilage Repair Society score) were determined and compared with follow-up data by using the paired Wilcoxon test.

RESULTS

The ICRS and modified Cincinnati score showed significant improvement (P < .01) in all time intervals between preoperative and 6, 18, and 36 months after surgery. There was no significant difference in the final outcome between different defect localizations (P > .2). The Pearson coefficient of correlation between clinical and MRI scores was 0.73 and significant at the 0.01 level. There was no patient with a symptomatic graft hypertrophy.

CONCLUSIONS

ACI is an effective method in the treatment of isolated cartilage defects in the knee. Graft hypertrophy can be avoided by using a collagen membrane. Significant improvement (P < .001) occurs still between 18 and 36 months after surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.