46 Sacral chordoma patients treated between 1987 and 2004 are reviewed. The importance of early diagnosis, adequate surgical margin and post operative radiotherapy for optimum outcome and survival is stressed.

There were 33 male and 13 female patients, with a mean age of 61 years (38–73 years). The surgical approach depended on the level and extent of the lesion, with an anteroposterior approach used in 23 and posterior approach in 17 patients. 20 had partial sacrectomy, 17 had subtotal sacrectomy and 3 underwent total sacrectomy. 6 patients were deemed inoperable and received palliative therapy. 14 patients received radiotherapy post-operatively. The length of average follow up was 4.27 years (range 2–15.7 years).

Low back pain was the most common presenting symptom (80%), and 50% patients had a palpable mass. The mean duration of symptoms prior to diagnosis was 2 years (range 1 month–10 years). Examination revealed a palpable mass in 7 both externally and on rectal examination. 10 had a palpable mass on rectal examination but not externally. 2 patients presented with multiple metastases and another 2 with widespread local disease. Excision was complete in 23 patients and incomplete in 17. Histology revealed dedifferentiation in 4. Complete excision margin was achieved in 69.6% through combined approach and 52.9% through posterior approach only. 24 patients (52%) had local recurrence. Without adjuvant radiotherapy the mean disease free period following complete excision was 3.5 years, compared to 0.9 years following incomplete excision. Adjuvant radiotherapy extended the mean disease free period following incomplete excision to 1.8 years.

The authors conclude that an early diagnosis and careful examination is important. Wide excision remains the mainstay of treatment. If excision is incomplete radiotherapy increases the disease free period although local recurrence is inevitable. The use of a combined approach increases the likelihood of complete excision.

Purpose: To report the importance of early diagnosis, adequate surgical margin and postoperative radiotherapy for optimum outcome and survival.

Study Design: A retrospective review of 46 sacral chordoma patients treated between 1987 and 2004.

Methods: There were 33 male and 13 female patients, with mean age of 61 years (38 to 73 year). The surgical approach depended on the level and extent of the lesion, with an anteroposterior approach used in 23 and posterior approach in 17 patients. 20 had partial sacrectomy, 17 had subtotal sacrectomy and 3 underwent total sacrectomy. 6 patients were deemed inoperable and received palliative therapy. 14 patients received radiotherapy postoperatively. The length of average follow up was 4.27 years (range 2–15.7 years).

Results: Low back pain was the most common presenting symptom (80%), and 50% patients had a palpable mass. The mean duration of symptoms prior to diagnosis was 2 years (range 1 month–10 years). Examination revealed a palpable mass in 7 both externally and on rectal examination. 10 had palpable mass on rectal examination but not externally. 2 patients presented with multiple metastases and another 2 with widespread local disease.

Excision was complete in 23 patients and incomplete in 17. Histology revealed dedifferentiation in 4. Complete excision margin was achieved in 69.6% through combined approach and 52.9% through posterior approach only. 24 patients (52%) had local recurrence. Without adjuvant radiotherapy the mean disease-free period following complete excision was 3.5 years, compared to 0.9 years following incomplete excision. Adjuvant radiotherapy extended the mean disease-free period following incomplete excision to 1.8 years.

Conclusion: An early diagnosis and careful examination is important. Wide excision remains the mainstay of treatment. If excision is incomplete radiotherapy increases the disease free period although local recurrence is inevitable. Use of combined approach increases the likelihood of complete excision.

This prospective study analyses the histological results of autologous chondrocyte transplantation in patients with articular cartilage defects of the knee joint. Chondrocytes from a non-weight bearing area of the knee were harvested and then cultured in vitro.

Re-implantation involved injection of the chondrocytes into the defect, which was then sealed with a collagen membrane. One year post-op, patients were evaluated by clinical, arthroscopic and histological assessment. A biopsy of the transplanted region was examined by staining with Erlich’s H& E and Safranin 0, polarised light microscopy and by analysis with S100 and immunohistochemistry. Hyaline cartilage content was further assessed by examination of Type IIa & lIb collagen mRNA expression using in-situ hybridisation.

The median age was 31 years. 63 knees were treated. Solitary lesions were treated in 61 knees with two defects being treated in three knees (66 defects in total). The defects were located on the medial femoral condyle in 39 cases, lateral femoral condyle in 14, trochlea in 2 and patella in 11. The defect size ranged from 1–7 cm2 (mean area 3cm2 ). 40 patients had at least one-year follow-up. Using the Brittberg Rating, 11 had excellent results, with 15 good, 10 fair and 4 poor. The mean Lysholm and Gillquist scores improved from 44 pre-op to 77 one-year post-op. Biopsy at one year conftrmed the presence of hyaline cartilage in 22 out of 32 cases (69%). In-situ hybridisation confirmed the presence of Collagen type II in the deep zones of the biopsy with a fibrocartilaginous appearance superficially.

Conclusion: This technique can provide an effective treatment for cartilage defects. The histological results are encouraging and chondrocyte transplantation may be the only procedure to allow regeneration of hyaline like articular cartilage.

We reviewed 234 benign solitary schwannomas treated between 1984 and 2004. The mean age of the patients was 45.2 years (11 to 82). There were 170 tumours (73%) in the upper limb, of which 94 (40%) arose from the brachial plexus or other nerves within the posterior triangle of the neck. Six (2.6%) were located within muscle or bone. Four patients (1.7%) presented with tetraparesis due to an intraspinal extension.

There were 198 primary referrals (19 of whom had a needle biopsy in the referring unit) and in these patients the tumour was excised. After having surgery or an open biopsy at another hospital, a further 36 patients were seen because of increased neurological deficit, pain or incomplete excision. In these, a nerve repair was performed in 18 and treatment for pain or paralysis was offered to another 14.

A tender mass was found in 194 (98%) of the primary referrals. A Tinel-like sign was recorded in 155 (81%). Persistent spontaneous pain occurred in 60 (31%) of the 194 with tender mass, impairment of cutaneous sensibility in 39 (20%), and muscle weakness in 24 (12%).

After apparently adequate excision, two tumours recurred. No case of malignant transformation was seen.

Osteofibrous dysplasia is an unusual developmental condition of childhood, which almost exclusively affects the tibia. It is thought to follow a slowly progressive course and to stabilise after skeletal maturity. The possible link with adamantinoma is controversial and some authors believe that they are part of one histological process.

We retrospectively reviewed 16 patients who were diagnosed as having osteofibrous dysplasia initially or on the final histological examination. Their management was diverse, depending on the severity of symptoms and the extent of the lesion. Definitive (extraperiosteal) surgery was localised ‘shark-bite’ excision for small lesions in five patients. Extensive lesions were treated by segmental excision and fibular autograft in six patients, external fixation and bone transport in four and proximal tibial replacement in one. One patient who had a fibular autograft required further excision and bone transport for recurrence. Six initially underwent curettage and all had recurrence. There were no recurrences after localised extraperiosteal excision or bone transport. There were three confirmed cases of adamantinoma.

The relevant literature is reviewed. We recommend extraperiosteal excision in all cases of osteofibrous dysplasia, with segmental excision and reconstruction in more extensive lesions.

Adamantinoma is a rare low-grade malignant epithelial bone tumour.

We report a case of an expansile, osteolytic mid-diaphyseal tibial lesion found in a 12 year-old girl. An initial histological diagnosis of basaloid-type adamantinoma was made. Following excision, further histology demonstrated basaloid cells and acellular matrix focally surrounded by osteoclast giant cells with calcium deposits, features consistent with pilomatrixoma. Several histological variants of adamantinoma have been documented; this case details a previously unreported histological adamantinoma variant – pilomatrixoma-adaminatinoma.

Aim: This prospective study analyses the histological results of autologous chondrocyte transplantation in patients with articular cartilage defects of the knee joint.

Methods: This is a prospective, single centre, single surgeon study. Consecutive patients undergoing autologous chondrocyte transplantation were studied. Chondrocytes from a non-weight bearing area of the knee were harvested and then cultured in vitro. Re-implantation involved injection of the chondrocytes into the defect, which was then sealed with a collagen membrane. One year post-op, patients were evaluated by clinical, arthroscopic and histological assessment. A biopsy of the transplanted region was examined by staining with Erlich’s H& E and Safranin O, polarised light microscopy and by analysis with S100 and immunohistochemistry. Hyaline cartilage content was further assessed by examination of Type IIa & IIb collagen mRNA expression using in-situ hybridisation.

Results: The median age was 31 years. 63 knees were treated. Solitary lesions were treated in 61 knees with two defects being treated in three knees (66 defects in total). The defects were located on the medial femoral condyle in 39 cases, lateral femoral condyle in 14, trochlea in 2 and patella in 11. The defect size ranged from 1–7 cm2 (mean area 3cm2). 40 patients had at least two-year follow-up. Using the Brittberg Rating, 11 had excellent results, with 15 good, 10 fair and 4 poor. The mean Lysholm and Gillquist scores improved from 44 pre-op to 77 two-years post-op. Biopsy at one year confirmed the presence of hyaline cartilage in 22 out of 32 cases (69%). In-situ hybridisation confirmed the presence of Collagen type II in the deep zones of the biopsy with a fibrocartilaginous appearance superficially.

Conclusion This technique can provide an effective treatment for cartilage defects. The histological results are encouraging. Chondrocyte transplantation appears to regenerate tissue with the features of normal hyaline cartilage.

The purpose of this study is to demonstrate that definitive surgery (extraperiosteal excision) is required in patients with osteofibrous dysplasia (OFD) due to the risk of recurrence and co-existent adamantinoma

OFD is an unusual childhood condition, which almost exclusively affects the tibia. It is thought to follow a slowly progressive course and to stabilise after skeletal maturity. The possible link with adamantinoma is controversial with some authors believing that they are part of one histological process. This therefore provides difficulty in recommending treatment options

A retrospective review of OFD was conducted. Using the Stanmore Bone Tumour Unit database 22 cases were identified who were initially diagnosed with OFD or were diagnosed on final histology. All cases were tibial except one lesion in the ulna and one in the fibula

Management was diverse depending on the severity of symptoms and the extent of the lesions encountered. Definitive (extraperiosteal) surgery in the majority of our patients was localized excision for small lesions (less than 50% of the bony circumference) and segmental excision followed by reconstructive surgery for more extensive ones. Seven patients had a sharkbite excision and a further seven were treated with fibula autografting. Of the latter group, one required further excision and bone transport due to recurrence of OFD. An additional five underwent bone transport & distraction osteogenesis using the Ilizarov technique and one had a proximal tibial replacement. Nine initially underwent curettage, but eight recurred (recurrence rate 88.9%). No recurrences occurred following localized extraperiosteal excisions and bone transport. There were three confirmed cases of adamantinoma.

In view of the risk of association of OFD with adamantinoma, and to some extent the continuous morbidity of OFD if left untreated, we believe that radical extraperiosteal excision is indicated in most if not all cases of OFD

Introduction: The purpose of this study is to demonstrate that definitive surgery (extraperiosteal excision) is required in patients with osteofibrous dysplasia (OFD) due to the risk of recurrence and co-existent adamantinoma. The possible link with adamantinoma is controversial with some authors believing that they are part of one histological process. This therefore provides difficulty in recommending treatment options.

Methods: Using our database 22 cases of OFD were identified. Management was diverse.

Results: Definitive (extraperiosteal) surgery, in the majority of our patients, was localized excision for small lesions (less than 50% of the bony circumference) and segmental excision followed by reconstructive surgery for more extensive ones. Seven patients had a “shark-bite” excision and a further seven were treated with fibula autografting. Of the latter group, one required further excision and bone transport due to recurrence of OFD. Five underwent bone transport & distraction osteogenesis and one had a proximal tibial replacement. Nine initially underwent curettage, but eight recurred. No recurrences occurred following localized extraperiosteal excisions and bone transport. There were three confirmed cases of adamantinoma.

Discussion: In view of the risk of association of OFD with adamantinoma, and to some extent the continuous morbidity of OFD if left untreated, we believe that radical extraperiosteal excision is indicated in most if not all cases of OFD.

Introduction and Aim: The purpose of this study is to demonstrate that definitive surgery (extraperiosteal excision) is required in patients with osteofibrous dysplasia (OFD) due to the risk of recurrence and co-existent adamantinoma. OFD is an unusual childhood condition, which almost exclusively affects the tibia. It is thought to follow a slowly progressive course and to stabilise after skeletal maturity. The possible link with adamantinoma is controversial, with some authors believing that they are part of one histological process. This therefore provides difficulty in recommending treatment options.

Method and Results: A retrospective review of OFD was conducted. Using the Stanmore Bone Tumor Unit database, 22 cases were identified who were initially diagnosed with OFD or were diagnosed on final histology. All cases were tibial except one lesion in the ulna and one in the fibula. Management was diverse, depending on the severity of symptoms and the extent of the lesions encountered. Definitive (extraperiosteal) surgery in the majority of our patients was localised excision for small lesions (less than 50% of the bony circumference) and segmental excision followed by reconstructive surgery for more extensive ones. Seven patients had a ‘sharkbite’ excision and a further seven were treated with fibula autografting. Of the latter group, one required further excision and bone transport due to recurrence of OFD. An additional five underwent bone transport and distraction osteogenesis using the Ilizarov technique and one had a proximal tibial replacement. Nine initially underwent curettage, but eight recurred (recurrence rate 88.9%). No recurrences occurred following localised extraperiosteal excisions and bone transport. There were three confirmed cases of adamantinoma

Conclusion: In view of the risk of association of OFD with adamantinoma, and to some extent the continuous morbidity of OFD if left untreated, we believe that radical extraperiosteal excision is indicated in most if not all cases of OFD

Purpose- To review the operative treatment of patients with chondrosarcoma of the pelvis and to study the long-term survival analysis of this cohort group.

Methods- A retrospective case study analysis was performed of patients with a diagnosis of chondrosarcoma of the pelvis treated in our hospital between 1990 and 2003. The operative notes and histopathological records were used along with the latest follow up letters.

Results- 54 cases (32 males and 22 females) with a mean age of 48.4 years ( 18–77) were identified. The aetiology was primary ( 38), recurrences ( 9) and secondaries ( 7).The sites in the pelvis were in the anatomical epicentre I(24), II(20) and III(10).The surgical procedures performed were local resection (28) , local resection and hip arthoplasty (6), hemipelvectomy (+ endoprosthesis) (16), hemipelvectomy (+ fibular strut graft) (2) and hindquater amputation (2).The histological grade was grade 1 (27), grade 2 (20) and grade 3(7). The complications rate was 24% – Wound revision (9%), dislocation (8%) and infection (7%). There was a 14-year cumulative survival rate of 46 % and 24 patients are surviving to date. The median follow up was 52 months.

The cumulative 14-year recurrence rate was 40% and the mean time to recurrence was 20.2 months.

Conclusion- There is an increased recurrence rate with epicentre I and III tumours and with those treated by local excision.

Aim: Sacral tumours are rare and can form a wide variety of differential diagnoses. We present a series of sacral tumour patients treated at a regional tumour centre; describing our experience of their management. Method: A retrospective study reviewing 76 sacral tumour patients, presenting to the Royal National Orthopaedic Hospital, Stanmore, from April 1976 to April 2002. The minimum follow-up period was 6 months. For each tumour type we looked at the incidence, diagnosis and outcome. Results: 69 of the lesions were primary bone tumours, 3 metastatic and 4 haematopoietic tumours. 33% of all tumours were chordomas. Osteosarcoma (10%), chondrosarcoma (8%) and giant cell tumour (8%) were the next most common. The commonest presenting symptom was lower back pain (64 cases). Good survival was demonstrated with chordomas and giant cell tumours. Osteosarcomas and chondrosarcomas had poor survival. Tissue diagnosis was accurately achieved with image-guided needle biopsy (61 cases). Magnetic resonance imaging (MRI) and computed tomography (CT) provided sufficient details for preoperative planning. Conclusion: The symptoms and signs of sacral tumours are non-specific and may lead to a misdiagnosis of degenerative disease of the spine. In our series chordomas account for only a third of all sacral tumours. Early diagnosis and staging are essential in order to determine definitive management and infl uence outcome. Surgery remains the most effective method for treating the malignant tumours.

Aim: Chordomas are relatively rare, malignant and strictly found in the midline. This study is to review our experience in the diagnosis, treatment and outcome of sacral chordomas. Method: A retrospective study reviewing 25 sacral chordoma patients treated at the Royal National Orthopaedic Hospital between August 1987 and April 2002, with a minimum follow-up of 6 months. Results: Of the 25 patients, 17 were male and 8 were female. The mean age at diagnosis was 61 years, and the mean duration of symptoms was 2 years. The commonest presenting symptom was lower back pain (20 cases). Three patients had inoperable tumours at the time of referral; the remaining 22 underwent surgical excision. A complete excision (based on microscopic examination) was achieved in11 cases, 2 of whom received adjuvant radiotherapy. Of the11 who had an incomplete excision 8 received adjuvant radiotherapy. Complete excision extended the mean disease free period to2.92 years, compared to 0.67 years following incomplete excision. The disease free period following an incomplete excision was extended from a mean of 0.67 years to 2.82 years with radiotherapy. 10 patients had postoperative neurological complications. Conclusion: We believe that the aim of surgical resection should be a microscopically complete excision margin, having documented an increased time to recurrence in patients in whom this has been achieved, compared to those treated with an incomplete excision. Radiation therapy should be given after an incomplete excision as we have shown that it lengthens the disease free interval in these cases.

Aims: Damage to articular hyaline cartilage may predispose to earlyonset osteoarthritis. Hyaline cartilage has not been shown to spontaneously regenerate and previous methods of stimulating repair have often yielded þbrocartilage. Autologous chondrocyte implantation (ACI) offers the potential for hyaline cartilage repair. Methods: A prospective study of 31 patients undergoing ACI using the chondrogide membrane. Patients were assessed clinically using validated knee scores pre-operatively and post-operatively at yearly intervals. Arthroscopy was carried out at one year post implantation and a biopsy of the transplanted area was sent for histological examination. Results: 32 knees (including 2 bilateral) were reviewed clinically at one year, and 15 were reviewed at 2 years. 33 defects (including 2 defects in one knee) were assessed arthroscopically at one year. Only one repair showed hypertrophy at one-year arthroscopy, and 8 had poor integration. Hyaline-like cartilage was demonstrated in 70% of the repairs. Patients showed improvement in the Verbal Numerical Pain scores and in the Lysholm and Gillquist score. Conclusions: In our series, the use of chondrogide membrane shows a low incidence of hypertrophy when compared to periosteum. Improvement in knee scores was statistically signiþcant at one and two years.

We have performed a prospective, single-surgeon study analysing the histological results of autologous chondrocyte implantation.

Fourteen patients underwent autologous chondrocyte implantation of the knee and were evaluated at one year by clinical assessment and arthroscopy. Standard staining was used to examine the sections. In addition, in situ hybridisation was used to establish type-IIa and type-IIb collagen mRNA expression and immunolocalisation techniques demonstrated the positions of type-II and type-X collagen.

Eight patients regenerated hyaline cartilage and also contained type-X collagen in the deepest layers and type-II collagen in the deep layers. Three demonstrated fibrocartilage and had type-II collagen in the deep layers. In situ hybridisation revealed that all 14 samples had the potential to express both type-IIa and type-IIb collagen.

We have shown that one year after the initial implantation chondrocytes are capable of producing type-II collagen and that they continue to proliferate and mature.

Autologous chondrocyte implantation (ACI) and mosaicplasty are both claimed to be successful for the repair of defects of the articular cartilage of the knee but there has been no comparative study of the two methods. A total of 100 patients with a mean age of 31.3 years (16 to 49) and with a symptomatic lesion of the articular cartilage in the knee which was suitable for cartilage repair was randomised to undergo either ACI or mosaicplasty; 58 patients had ACI and 42 mosaicplasty. Most lesions were post-traumatic and the mean size of the defect was 4.66 cm². The mean duration of symptoms was 7.2 years and the mean number of previous operations, excluding arthroscopy, was 1.5. The mean follow-up was 19 months (12 to 26).

Functional assessment using the modified Cincinatti and Stanmore scores and objective clinical assessment showed that 88% had excellent or good results after ACI compared with 69% after mosaicplasty. Arthroscopy at one year demonstrated excellent or good repairs in 82% after ACI and in 34% after mosaicplasty. All five patellar mosaicplasties failed.

Our prospective, randomised, clinical trial has shown significant superiority of ACI over mosaicplasty for the repair of articular defects in the knee. The results for ACI are comparable with those in other studies, but those for mosaicplasty suggest that its continued use is of dubious value.

We discuss the management and outcome of 52 patients who presented with malignant tumours of the fibula over a 15-year period between1983 and 1998.

The tumour type was Osteosarcoma (23 patients), Ewing’s sarcoma (16), Chondrosarcoma (11 – of which 10 low grade) and Malignant Fibrous Histiocytoma (2). We concentrate on the two most common frankly malignant groups: Osteosarcoma and Ewing’s.

The male:female ratio of patients with Osteosarcoma was 11:12 and with Ewing’s Sarcoma was 11:5. Mean age for Osteosarcoma was 21. 5 years and for Ewing’s Sarcoma was 14. 2. The most common site of tumour was in the proximal fibula in both Osteosarcoma (19 / 23) and Ewing’s Sarcoma (10 / 16). The stage of disease at presentation was IIa or IIb in the majority of patients, with seven patients presenting with metastases.

The current investigative procedures are Radiographs, Magnetic Resonance Imaging, Radioisotope Bone Scans, Computerised Tomography of the chest and needle biopsy whereas in the past CT of the lesion and open biopsy were common. Chemotherapy was administered as per protocol at the time of diagnosis and radiotherapy was given in selected cases.

Surgery was performed on all but 3 patients, who were unfit and died. This consisted of local en bloc resection in 86. 3% and above knee amputation in 6. 8%. Whereas all the diaphyseal and distal lesions were completely excised, 9 out of 26 proximal lesions had a marginal excision, 4 of which had open biopsies. The common peroneal nerve was sacrificed in 50% of cases and this had no link to survival.

The overall 5-year survival was 33% for Osteosarcoma and 40% for Ewing’s Sarcoma, with proximal lesions doing much worse than diaphyseal and distal lesions. Patients who had marginal excisions all died within 2. 5 years.

Mosaicplasty¹ and Autologous Chondrocyte Implantation² (ACI) are both modern cartilage repair techniques used to repair symptomatic articular cartilage defects in the knee, based on small osteochondral grafts and cultured chondrocytes respectively. The aim is the restoration of articular cartilage, but until now there is no data comparing the two methods.

100 consecutive patients aged 15–45 with a symptomatic articular cartilage lesion in the knee suitable for cartilage repair were randomised at arthroscopic assessment to undergo either mosaicplasty or ACI. 42 patients underwent mosaicplasty, 58 had ACI. Mean age at time of surgery was 31 years and the average defect size 4. 66 cm².

46% of the defects were post-traumatic, 19% had osteochondritis dissecans, 14% had chondromalacia patella and 16% had lesions of unknown aetiology. 53% had a medial femoral condyle lesion, 25% patella, 18% lateral femoral condyle, 3% trochlea and there was one defect of the lateral tibial plateau.

The mean duration of symptoms was 7. 2 years and the average number of previous operations (excluding arthroscopies) was 1. 5. Only 6 patients had no prior surgical interventions to the affected knee. The mean follow-up was 1. 7 years.

Patients were evaluated using Modified Cincinnati and Stanmore Functional rating systems, visual analogue scores and clinical assessment. Arthroscopy and biopsy was performed at one year and repair assessed with the International Cartilage Repair Society grading system.

Clinical results at one year showed 70% of mosaic-plasty patients and 87% of ACI patients had a good or excellent result. Arthroscopy at one year demonstrated more complete healing in ACI patients. Eleven (26%) of the mosaicplasty group subsequently failed clinically and arthroscopically, with peak failure at 2 years.

At one year follow-up, both techniques of articular cartilage repair can be useful in selected patients. ACI is preferred for lesions of the patella. Long-term follow-up is needed to assess the durability of articular cartilage repair using these methods, in particular mosaicplasty which showed signs of progressive failure over 2 years.

Autologous Chondrocyte Implantation’ (ACI) is a cartilage repair technique that involves implantation of cultured chondrocytes beneath a membrane of autologous periosteum. In this study a porcine biodegradable membrane was also used to assess its effectiveness. The aim is to restore articular cartilage to symptomatic defects, rather than initiating a fibrocartilagenous repair.

We undertook a prospective study of 125 consecutive patients who underwent ACI. Average age at the time of surgery was 30. 9 years (range 14 – 49), 55% of patients were male. The average size of the defect was 4. 35 cm².

44% of defects were attributable to known traumatic incidents, 2 1 % had osteochondritis dessicans, 18% chondromalacia patella, 12% had defects of unknown aetiology and 5% other.

The average duration of symptoms prior to this surgery was 7. 16 years. The mean number of previous operations (excluding arthroscopies) was 1. 6. Only 9 patients had no previous major surgery to the affected knee. 44% had defects of the medial femoral condyle, 31% patella, 20% lateral femoral condyle and 5% had a trochlea lesion. 26% of the defects were covered with periosteum and 74% with a porcine collagen membrane (chondrogide)

Minimum follow-up was six months, 70 patients had minimum follow-up of one year. Mean follow-up 18 months.

Patients were assessed using Modified Cincinnati and Stanmore Functional rating systems, visual analogue scores and clinical evaluation.

Arthroscopy and biopsy was performed at one year and the repair assessed using the International Cartilage Research Society grading system.

At one year follow-up overall 41 % patients had an excellent result, 48% good, 8% fair and 3% poor. For defects of the medial femoral condyle, 88% had a good or excellent result, 85% for the lateral femoral condyle and 80% for the patella.

61 patients were arthroscopically assessed at one year. 50/61 (82%) demonstrated ICRS grade 1 or 2 repair. Healing of the defect occurred with either a periosteum or chondrogide defect cover.

Results at one year suggest that ACI is a successful articular cartilage repair technique in selected patients. Long-term follow-up is required to assess the durability of the repair.