Autologous chondrocyte implantation (ACI) is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. We have performed a prospective, randomised comparison of ACI-C and MACI for the treatment of symptomatic chondral defects of the knee in 91 patients, of whom 44 received ACI-C and 47 MACI grafts. Both treatments resulted in improvement of the clinical score after one year. The mean modified Cincinnati knee score increased by 17.6 in the ACI-C group and 19.6 in the MACI group (p = 0.32). Arthroscopic assessments performed after one year showed a good to excellent International Cartilage Repair Society score in 79.2% of ACI-C and 66.6% of MACI grafts. Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in the biopsies of 43.9% of the ACI-C and 36.4% of the MACI grafts after one year. The rate of hypertrophy of the graft was 9% (4 of 44) in the ACI-C group and 6% (3 of 47) in the MACI group. The frequency of re-operation was 9% in each group. We conclude that the clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI. While MACI is technically attractive, further long-term studies are required before the technique is widely adopted

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 analysed whether a high body mass index (BMI) had a deleterious effect on outcome following autologous chondrocyte implantation (ACI) or matrix-carried autologous chondrocyte implantation (MACI) for the treatment of full-thickness chondral defects of the knee from a subset of patients enrolled in the ACI vs MACI trial at The Royal National Orthopaedic Hospital.

The mean Modified Cincinnati scores (MCS) were significantly higher (p < 0.001) post-operatively in patients who had an ideal body weight (n = 53; 20 to 24.9 kg/m²) than in overweight (n = 63; 25 to 30 kg/m²) and obese patients (n = 22; > 30 kg/m²). At a follow-up of two years, obese patients demonstrated no sustained improvement in the MCS. Patients with an ideal weight experienced significant improvements as early as six months after surgery (p = 0.007). In total, 82% of patients (31 of 38) in the ideal group had a good or excellent result, compared with 49% (22 of 45) of the overweight and 5.5% (one of 18) in the obese group (p < 0.001). There was a significant negative relationship between BMI and the MCS 24 months after surgery (r = -0.4, p = 0.001).

This study demonstrates that obese patients have worse knee function before surgery and experience no sustained benefit from ACI or MACI at two years after surgery. There was a correlation between increasing BMI and a lower MCS according to a linear regression analysis. On the basis of our findings patient selection can be more appropriately targeted.

Aims. Implantation of ultra-purified alginate (UPAL) gel is safe and effective in animal osteochondral defect models. This study aimed to examine the applicability of UPAL gel implantation to acellular therapy in humans with cartilage injury. Methods. A total of 12 patients (12 knees) with symptomatic, post-traumatic, full-thickness cartilage lesions (1.0 to 4.0 cm. 2. ) were included in this study. UPAL gel was implanted into chondral defects after performing bone marrow stimulation technique, and assessed for up to three years postoperatively. The primary outcomes were the feasibility and safety of the procedure. The secondary outcomes were self-assessed clinical scores, arthroscopic scores, tissue biopsies, and MRI-based estimations. Results. No obvious adverse events related to UPAL gel implantation were observed. Self-assessed clinical scores, including pain, symptoms, activities of daily living, sports activity, and quality of life, were improved significantly at three years after surgery. Defect filling was confirmed using second-look arthroscopy at 72 weeks. Significantly improved MRI scores were observed from 12 to 144 weeks postoperatively. Histological examination of biopsy specimens obtained at 72 weeks after implantation revealed an extracellular matrix rich in glycosaminoglycan and type II collagen in the reparative tissue. Histological assessment yielded a mean overall International Cartilage Regeneration & Joint Preservation Society II score of 69.1 points (SD 10.4; 50 to 80). Conclusion. This study provides evidence supporting the safety of acellular UPAL gel implantation in facilitating cartilage repair. Despite being a single-arm study, it demonstrated the efficacy of UPAL gel implantation, suggesting it is an easy-to-use, one-step method of cartilage tissue repair circumventing the need to harvest donor cells. Cite this article: Bone Joint J 2023;105-B(8):880–887

Autologous chondrocyte implantation (ACI) is a technique used for the treatment of symptomatic osteochondral defects of the knee. A variation of the original periosteum membrane technique is the matrix-induced autologous chondrocyte implantation (MACI) technique. The MACI membrane consists of a porcine type-I/III collagen bilayer seeded with chondrocytes. Osteochondral defects deeper than 8 to 10 mm usually require bone grafting either before or at the time of transplantation of cartilage. We have used a variation of Peterson’s ACI-periosteum sandwich technique using two MACI membranes with bone graft which avoids periosteal harvesting. The procedure is suture-free and requires less operating time and surgical exposure. We performed this MACI-sandwich technique on eight patients, five of whom were assessed at six months and one year post-operatively using the modified Cincinnati knee, the Stanmore functional rating and the visual analogue pain scores. All patients improved within six months with further improvement at one year. The clinical outcome was good or excellent in four after six months and one year. No significant graft-associated complications were observed. Our early results of the MACI-sandwich technique are encouraging although larger medium-term studies are required before there is widespread adoption of the technique

We investigated the prognostic indicators for collagen-covered autologous chondrocyte implantation (ACI-C) performed for symptomatic osteochondral defects of the knee. We analysed prospectively 199 patients for up to four years after surgery using the modified Cincinnati score. Arthroscopic assessment and biopsy of the neocartilage was also performed whenever possible. The favourable factors for ACI-C include younger patients with higher pre-operative modified Cincinnati scores, a less than two-year history of symptoms, a single defect, a defect on the trochlea or lateral femoral condyle and patients with fewer than two previous procedures on the index knee. Revision ACI-C in patients with previous ACI and mosaicplasties which had failed produced significantly inferior clinical results. Gender (p = 0.20) and the size of the defect (p = 0.97) did not significantly influence the outcome

Autologous chondrocyte implantation is an established method of treatment for symptomatic articular defects of cartilage. CARTIPATCH is a monolayer-expanded cartilage cell product which is combined with a novel hydrogel to improve cell phenotypic stability and ease of surgical handling. Our aim in this prospective, multicentre study on 17 patients was to investigate the clinical, radiological, arthroscopic and histological outcome at a minimum follow-up of two years after the implantation of autologous chondrocytes embedded in a three-dimensional alginate-agarose hydrogel for the treatment of chondral and osteochondral defects. Clinically, all the patients improved significantly. Patients with lesions larger than 3 cm. 2. improved significantly more than those with smaller lesions. There was no correlation between the clinical outcome and the body mass index, age, duration of symptoms and location of the defects. The mean arthroscopic International Cartilage Repair Society score was 10 (5 to 12) of a maximum of 12. Predominantly hyaline cartilage was seen in eight of the 13 patients (62%) who had follow-up biopsies. Our findings suggest that autologous chondrocyte implantation in combination with a novel hydrogel results in a significant clinical improvement at follow-up at two years, more so for larger and deeper lesions. The surgical procedure is uncomplicated, and predominantly hyaline cartilage-like repair tissue was observed in eight patients

The management of failed autologous chondrocyte implantation (ACI) and matrix-assisted autologous chondrocyte implantation (MACI) for the treatment of symptomatic osteochondral defects in the knee represents a major challenge. Patients are young, active and usually unsuitable for prosthetic replacement. This study reports the results in patients who underwent revision cartilage transplantation of their original ACI/MACI graft for clinical or graft-related failure. We assessed 22 patients (12 men and 10 women) with a mean age of 37.4 years (18 to 48) at a mean of 5.4 years (1.3 to 10.9). The mean period between primary and revision grafting was 46.1 months (7 to 89). The mean defect size was 446.6 mm. 2. (150 to 875) and they were located on 11 medial and two lateral femoral condyles, eight patellae and one trochlea. . The mean modified Cincinnati knee score improved from 40.5 (16 to 77) pre-operatively to 64.9 (8 to 94) at their most recent review (p < 0.001). The visual analogue pain score improved from 6.1 (3 to 9) to 4.7 (0 to 10) (p = 0.042). A total of 14 patients (63%) reported an ‘excellent’ (n = 6) or ‘good’ (n = 8) clinical outcome, 5 ‘fair’ and one ‘poor’ outcome. Two patients underwent patellofemoral joint replacement. This study demonstrates that revision cartilage transplantation after primary ACI and MACI can yield acceptable functional results and continue to preserve the joint. Cite this article: Bone Joint J 2014;96-B:54–8

Aims

The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.

Aims

The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Aims

The aim of this study was to report the outcome of femoral condylar fresh osteochondral allografts (FOCA) with concomitant realignment osteotomy with a focus on graft survivorship, complications, reoperation, and function.

Aim

Mesenchymal stem cells (MSCs) have several properties that may support their use as an early treatment option for osteoarthritis (OA). This study investigated the role of multiple injections of allogeneic bone marrow-derived stem cells (BMSCs) to alleviate the progression of osteoarthritic changes in the various structures of the mature rabbit knee in an anterior cruciate ligament (ACL)-deficient OA model.

The treatment of osteochondral lesions is of great interest to orthopaedic surgeons because most lesions do not heal spontaneously. We present the short-term clinical outcome and MRI findings of a cell-free scaffold used for the treatment of these lesions in the knee. A total of 38 patients were prospectively evaluated clinically for two years following treatment with an osteochondral nanostructured biomimetic scaffold. There were 23 men and 15 women; the mean age of the patients was 30.5 years (15 to 64). Clinical outcome was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner activity scale and a Visual Analgue scale for pain. MRI data were analysed based on the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system at three, 12 and 24 months post-operatively. There was a continuous significant clinical improvement after surgery. In two patients, the scaffold treatment failed (5.3%) There was a statistically significant improvement in the MOCART precentage scores. The repair tissue filled most of the defect sufficiently. We found subchondral laminar changes in all patients. Intralesional osteophytes were found in two patients (5.3%). We conclude that this one-step scaffold-based technique can be used for osteochondral repair. The surgical technique is straightforward, and the clinical results are promising. The MRI aspects of the repair tissue continue to evolve during the first two years after surgery. However, the subchondral laminar and bone changes are a concern.

Cite this article: Bone Joint J 2015; 97-B:318–23.

The aim of this study was to assess the effect of injecting genetically engineered chondrocytes expressing transforming growth factor beta 1 (TGF-β1) into the knees of patients with osteoarthritis. We assessed the resultant function, pain and quality of life.

A total of 54 patients (20 men, 34 women) who had a mean age of 58 years (50 to 66) were blinded and randomised (1:1) to receive a single injection of the active treatment or a placebo. We assessed post-treatment function, pain severity, physical function, quality of life and the incidence of treatment-associated adverse events. Patients were followed at four, 12 and 24 weeks after injection.

At final follow-up the treatment group had a significantly greater improvement in the mean International Knee Documentation Committee score than the placebo group (16 points; -18 to 49, vs 8 points; -4 to 37, respectively; p = 0.03). The treatment group also had a significantly improved mean visual analogue score at final follow-up (-25; -85 to 34, vs -11 points; -51 to 25, respectively; p = 0.032). Both cohorts showed an improvement in Western Ontario and McMaster Osteoarthritis Index and Knee Injury and Osteoarthritis Outcome Scores, but these differences were not statistically significant. One patient had an anaphylactic reaction to the preservation medium, but recovered within 24 hours. All other adverse events were localised and resolved without further action.

This technique may result in improved clinical outcomes, with the aim of slowing the degenerative process, leading to improvements in pain and function. However, imaging and direct observational studies are needed to verify cartilage regeneration. Nevertheless, this study provided a sufficient basis to proceed to further clinical testing.

Cite this article: Bone Joint J 2015;97-B:924–32.

Osteochondritis Dissecans (OCD) is a condition for which the aetiology remains unknown. It affects subchondral bone and secondarily its overlying cartilage and is mostly found in the knee. It can occur in adults, but is generally identified when growth remains, when it is referred to as juvenile OCD. As the condition progresses, the affected subchondral bone separates from adjacent healthy bone, and can lead to demarcation and separation of its associated articular cartilage. Any symptoms which arise relate to the stage of the disease. Early disease without separation of the lesion results in pain. Separation of the lesion leads to mechanical symptoms and swelling and, in advanced cases, the formation of loose bodies.

Early identification of OCD is essential as untreated OCD can lead to the premature degeneration of the joint, whereas appropriate treatment can halt the disease process and lead to healing. Establishing the stability of the lesion is a key part of providing the correct treatment. Stable lesions, particularly in juvenile patients, have greater propensity to heal with non-surgical treatment, whereas unstable or displaced lesions usually require surgical management.

This article discusses the aetiology, clinical presentation and prognosis of OCD in the knee. It presents an algorithm for treatment, which aims to promote healing of native hyaline cartilage and to ensure joint congruity.

Take home message: Although there is no clear consensus as to the best treatment of OCD, every attempt should be made to retain the osteochondral fragment when possible as, with a careful surgical technique, there is potential for healing even in chronic lesions

Cite this article: Bone Joint J 2016;98-B:723–9.

The aim of this study was to examine the functional outcome at ten years following lateral closing wedge high tibial osteotomy for medial compartment osteoarthritis of the knee and to define pre-operative predictors of survival and determinants of functional outcome.

164 consecutive patients underwent high tibial osteotomy between 2000 and 2002. A total of 100 patients (100 knees) met the inclusion criteria and 95 were available for review at ten years. Data were collected prospectively and included patient demographics, surgical details, long leg alignment radiographs, Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and Knee Society scores (KSS) pre-operatively and at five and ten years follow-up.

At ten years, 21 patients had been revised at a mean of five years. Overall Kaplan–Meier survival was 87% (95% confidence interval (CI) 81 to 94) and 79% (95% CI 71 to 87) at five and ten years, respectively. When compared with unrevised patients, those who had been revised had significantly lower mean pre-operative WOMAC Scores (47 (21 to 85) vs 65 (32 to 99), p < 0.001), higher mean age (54 yrs (42 to 61) vs 49 yrs (26 to 66), p = 0.006) and a higher mean BMI (30.2; 25 to 39 vs 27.9; 21 to 36, p = 0.005). Each were found to be risk factors for revision, with hazard ratios of 10.7 (95% CI 4 to 28.6; pre-operative WOMAC < 45), 6.5 (95% CI 2.4 to 17.7; age > 55) and 3.0 (95%CI 1.2 to 7.6; BMI > 30). Survival of patients with pre-operative WOMAC > 45, age < 55 and BMI < 30 was 97% at five and ten years. WOMAC and KSS in surviving patients improved significantly between pre-operative (mean 61; 32 to 99) and five (mean 88; 35 to 100, p = 0.001) and ten years (mean 84; 38 to 100, p = 0.001). Older patients had better functional outcomes overall, despite their higher revision rate.

This study has shown that improved survival is associated with age < 55 years, pre-operative WOMAC scores > 45 and, a BMI < 30. In patients over 55 years of age with adequate pre-operative functional scores, survival can be good and functional outcomes can be significantly better than their younger counterparts. We recommend the routine use of pre-operative functional outcome scores to guide decision-making when considering suitability for high tibial osteotomy.

Cite this article: Bone Joint J 2014;96-B:1491–7.

Hypermobility is an acknowledged risk factor for patellar instability. In this case control study the influence of hypermobility on clinical outcome following medial patellofemoral ligament (MPFL) reconstruction for patellar instability was studied.

A total of 25 patients with hypermobility as determined by the Beighton criteria were assessed and compared with a control group of 50 patients who were matched for age, gender, indication for surgery and degree of trochlear dysplasia. The patients with hypermobility had a Beighton Score of ≥ 6; the control patients had a score of < 4. All patients underwent MPFL reconstruction performed using semitendinosus autograft and a standardised arthroscopically controlled technique. The mean age of the patients was 25 years (17 to 49) and the mean follow-up was 15 months (6 to 30).

Patients with hypermobility had a significant improvement in function following surgery, with reasonable rates of satisfaction, perceived improvement, willingness to repeat and likelihood of recommendation. Functional improvements were significantly less than in control patients (p < 0.01).

Joint hypermobility is not a contraindication to MPFL reconstruction although caution is recommended in managing the expectations of patients with hypermobility before consideration of surgery.

We present a prospective review of the two-year functional outcome of 37 Avon patellofemoral joint replacements carried out in 29 patients with a mean age of 66 years (30 to 82) between October 2002 and March 2007. No patients were lost to follow-up. This is the first independent assessment of this prosthesis using both subjective and objective analysis of outcome. At two years the median Oxford knee score was 39 (interquartile range 32 to 44), the median American Knee Society objective score was 95 (interquartile range 90 to 100), the median American Knee Society functional score was 85 (interquartile range 60 to 100), and the median Melbourne Knee score was 28 (interquartile range 21 to 30). Two patients underwent further surgery. Only one patient reported an unsatisfactory outcome.

We conclude that the promising early results observed by the designing centre are reproducible and provide further support for the role of patellofemoral joint replacement.

Autologous chondrocyte implantation is an option in the treatment of full-thickness chondral or osteochondral injuries which are symptomatic. The goal of surgery and rehabilitation is the replacement of damaged cartilage with hyaline or hyaline-like cartilage, producing improved levels of function and preventing early osteoarthritis. The intermediate results have been promising in terms of functional and clinical improvement.

Our aim was to explore the hypothesis that the histological quality of the repair tissue formed after autologous chondrocyte implantation improved with increasing time after implantation.

In all, 248 patients who had undergone autologous chondrocyte implantation had biopsies taken of the repair tissue which then underwent histological grading. Statistical analysis suggested that with doubling of the time after implantation the likelihood of a favourable histological outcome was increased by more than fourfold (p < 0.001).

We prospectively studied the clinical, arthroscopic and histological results of collagen-covered autologous chondrocyte implantation (ACI-C) in patients with symptomatic osteochondritis dissecans of the knee. The study included 37 patients who were evaluated at a mean follow-up of 4.08 years.

Clinical results showed a mean improvement in the modified Cincinnati score from 46.1 to 68.4. Excellent and good clinical results were seen in 82.1% of those with juvenile-onset osteochondritis dissecans but in only 44.4% of those with adult-onset disease.

Arthroscopy at one year revealed International Cartilage Repair Society grades of 1 or 2 in 21 of 24 patients (87.5%). Of 23 biopsies, 11 (47.8%) showed either a hyaline-like or a mixture of hyaline-like and fibrocartilage, 12 (52.2%) showed fibrocartilage.

The age at the time of ACI-C determined the clinical outcome for juvenile-onset disease (p = 0.05), whereas the size of the defect was the major determinant of outcome in adult-onset disease (p = 0.01).