Objectives

Subtotal or total meniscectomy in the medial or lateral compartment of the knee results in a high risk of future osteoarthritis. Meniscal allograft transplantation has been performed for over thirty years with the scientifically plausible hypothesis that it functions in a similar way to a native meniscus. It is thought that a meniscal allograft transplant has a chondroprotective effect, reducing symptoms and the long-term risk of osteoarthritis. However, this hypothesis has never been tested in a high-quality study on human participants. This study aims to address this shortfall by performing a pilot randomised controlled trial within the context of a comprehensive cohort study design.

Abstract. Background. Osteochondral allograft (OCA) transplantation is a clinically and cost-effective option for symptomatic cartilage defects. In 2017 we initiated a program for OCA transplantation for complex chondral and osteochondral defects as a UK tertiary referral centre. Aim. To characterise the complications, re-operation rate, graft survivorship and clinical outcomes of knee OCA transplantation. Methodology. Analysis of a prospectively maintained database of patients treated with primary OCA transplantation from 2017 to 2021 with a minimum of one-year follow-up. Patient reported outcome measures (PROMs), complications, re-operations and failures were evaluated. Results. 37 patients with 37 knee OCA procedures were included (mean age 31.6 years [16–49 years]). Mean BMI 26.6 kg/m2 (19.1–35.9 kg/m2). The mean chondral defect size was 3cm2 (1.2–7.3 cm2). Mean duration of follow-up was 3.1 years (1–5.3 years). 16 patients underwent meniscal allograft transplantation (MAT), 6 underwent osteotomy and 4 underwent ligament reconstruction as concurrent procedures. Significant improvements in mean PROMs were noted at 12 months. 16 patients had reoperations of which 5 had more than one surgery. Of these patients 6 were related to OCA (mainly debridement and revision OCA in one patient), and the remainder were related to additional procedures including removal of plate in 2 patients. The overall failure rate was 1 in 37 patients (3%). Conclusions. Early experience of OCA as a treatment option for complex chondral and osteochondral lesions in the knee shows satisfactory results. The reoperation rate is high but at mean follow-up of 3.1 years the survival rate was 97%

Background. There is growing evidence in literature that meniscal allograft transplantation performed with the right indications results in significant pain relief and functional improvement of the involved joint. Long-term data on clinical and radiological outcome are however scarce. Methods. We evaluated 89 transplants (53 lateral and 36 medial) in 87 patients. Mean time of follow-up was 15,5 ± 2,85 years (range 9,9–20,4), mean age at surgery was 35,2 years (range 22–50). Clinically, the patients were evaluated using a KOOS, SF-36, HSS, VAS, Tegner and Lysholm score. HSS scores were compared to pre-operative and mid-term follow-up data. Each patient received radiographs (AP, profile and Rosenberg view). Radiological outcome parameters were joint space width narrowing and Fairbank changes and were scored according to IKDC. Failures were defined as patients who were converted to an arthroplasty. Results. HSS-scores improved significantly from 119 ± 27pre-operatively to 160 ± 40 at long-term follow-up. Lysholm-score was 69 ± 22, which was defined as a fair result. Mean VAS-score was 3,4 ± 3, mean Tegner was 4 ± 2. There were no significant differences between following subgroups: left or right knee, medial or lateral allograft, combined procedure with a high tibial osteotomy and male or female. Nine (25%) of the thirty-six medial and ten (19%) of the fifty-three lateral grafts failed after a mean of 9,9 years. Conclusions. Transplantation of a viable meniscal allograft can significantly relieve pain and improve function of the knee joint. Survival analysis showed that this beneficial effect remained in approximately 70% of the patients at fifteen years. This study proves that meniscal allograft transplantation is a beneficial procedure to postpone total knee arthroplasty for more than 10 years in young active patients

One hundred and forty eight meniscus allografts transplanted in one hundred and forty patients between 1988 and 2000 were reviewed. The indication for surgery included disabling knee pain, refractory to conservative treatment, objective symptoms of compartmental crepitus, pain on valgus/varus stress and osteoarthritis documented on arthroscopy following prior total meniscectomy. Knee mal-alignment and instability were also documented. Patients with varus alignment and medial OA, as well as valgus alignment with lateral OA, underwent re-alignment to unload the compartment for allograft transplantation. Patients with anterior cruciate deficiency, underwent ACL reconstruction at the time of allograft transplantation. The purpose of this paper is to show the benefit of meniscus transplantation in osteoarthritis of the knee. At a mean follow-up of six years (range two to fourteen), one hundred and twenty-five out of one hundred and forty-eight knees received good to excellent results. Meniscus allograft transplantation can restore function in patients with arthritis secondary to prior total meniscectomy. The transplantation of a biological load-bearing structure has given reliable long term results, when used in well selected cases. Forty six patients received an isolated meniscus allograft with forty-one receiving good to excellent results. Eleven received a medial or lateral meniscus allograft with an ACL reconstruction and nine obtained good to excellent results. Seventy five knees received a meniscal allograft in combination with an osteotomy to correct for pre-operative deformity, with sixty-four attaining good to excellent results. The remaining twenty-two knees underwent valgus high tibial osteotomy, meniscus allograft and ACL repair, with nineteen achieving good to excellent results. Outcome was assessed subjectively and functionally using a modified Lysholm socre and objectively by clinical examination. The Tegner activity scale was used to compare pre and post- operative function. Second look arthroscopy was performed on the first ten transplanted meniscus to assess healing and graft integrity

Introduction: Meniscus allograft transplantation can restore function in patients with arthritis secondary to prior total meniscectomy. The transplantation of a biological load-bearing structure in young patients has given reliable long-term results, when used in well-selected cases. Method: One hundred and forty-eight meniscus allografts transplanted in l40 patients between 1988 and 2000 were reviewed. The indication for surgery included disabling knee pain, refractory to conservative treatment, objective symptoms of compartmental crepitus, pain on valgus/varus stress and osteoarthritis documented on arthroscopy following prior total meniscectomy. Knee mal-alignment and instability were also documented. Patients with varus alignment and medial OA, as well as valgus alignment with lateral OA, underwent re-alignment to unload the compartment for allograft transplantation. Patients with anterior cruciate deficiency, underwent ACL reconstruction at the time of allograft transplantation. Results: At a mean follow-up of six years (range two to 14). One hundred and twenty-five received a good to excellent result. Forty-six patients received an isolated meniscus allograft, with 41 receiving good to excellent results. Eleven received a medial or lateral meniscus allograft with an ACL reconstruction and nine obtained good to excellent results. Seventy-five knees received a meniscal allograft in combination with either a valgus high tibial osteotomy, varus high tibial osteotomy or varus distal femoral osteotomy to correct for pre-operative deformity with l26 attaining good to excellent results. The remaining 22 knees underwent valgus high tibial osteotomy, meniscal allograft and ACL repair with 19 receiving good to excellent results. Outcome was assessed subjectively and functionally using a modified Lysholm score and objectively by clinical examination of stress pain and joint crepitus. The Tegner activity scale comparing pre- and post-operative function was applied. Second-look arthroscopy was performed on the first l0 transplanted meniscii to assess healing and integrity of the transplantation graft. The most frequent complication was a traumatic posterior horn tear in l3 knees

Abstract. Objectives. Meniscus allograft and synthetic meniscus scaffold (Actifit. ®. ) transplantation have shown promising outcomes for symptoms relief in patients with meniscus deficient knees. Untreated chondral defects can place excessive load onto meniscus transplants and cause early graft failure. We hypothesised that combined ACI and allograft or synthetic meniscus replacement might provide a solution for meniscus deficient individuals with co-existing lesions in cartilage and meniscus. Methods. We retrospectively collected data from 17 patients (16M, 1F, aged 40±9.26) who had ACI and meniscus allograft transplant (MAT), 8 patients (7M, 1F, aged 42±11) who underwent ACI and Actifit. ®. meniscus scaffold replacement. Other baseline data included BMI, pre-operative procedures and cellular transplant data. Patients were assessed by pre-operative, one-year and last follow-up Lysholm score, one-year repair site biopsy, MRI evaluations. Results. In the MAT group, the final post-operative evaluation was 7±4.5 years. The mean pre-operative Lysholm score was 49±17, rose to 66.6±16.4 1 year post-op and dropped to 58±26 at final evaluation. Four of the 17 patients had total knee replacements (TKRs) at average 6.4 years after treatment. In the Actifit. ®. group, the final post-operative assessment was 5.6±2.7years. The pre-operative Lysholm score was 53.7±21.3, increasing to 72.8±15.2 at 1 year and 70.4±27.6 at final clinical follow-up. None of the patients in the Actifit® group had received TKRs. Conclusions. Both MAT and Actifit. ®. groups were effective in improving patients symptoms and knee function according to one-year post-operative assessments. However, the knee function of patients in MAT group dropped at final follow-up, whereas the Actifit® group maintained their knee function. These preliminary findings warrant further investigations, to include more patients and alongside comparisons to ACI alone and allograft/Actifit. ®. alone as comparator groups before accurate conclusions may be drawn on the comparative efficacy of each technique. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Background. The meniscal deficient knee often exists in the setting of associated pathology including instability, malalignment and chondral injury. Meniscal allograft transplantation (MAT) is established to be a reliable option in restoring function and treating symptoms. The aim of this study was to establish the role of MAT as part of a staged approach to treatment of the previously menisectomised knee. Methods. This prospective study included all patients that underwent arthroscopic MAT at our institution between 2010 to 2017. Fresh frozen allograft was utilised using a soft tissue fixation technique. Further data was collected for index surgical procedures before and after MAT. Data for pre and post-operative Knee Injury and osteoarthritis outcome scores (KOOS), Tegner scores, graft survival, reoperation rates, patient satisfaction and MRI extrusion measurements were collected and details of any further surgical intervention and / or complications also documented. Results. Twenty seven MAT procedures were performed in 26 patients. Sixteen patients underwent lateral MAT and 11 patients medial. Ten patients underwent ACL reconstruction, three ACI and two, osteotomy in the pre-MAT phase. A further seven patients underwent ACI within the post-operative phase. The post-operative mean KOOS scores improved significantly in all subscales as did Tegner scores. Graft survival was 100%, satisfaction rate 92%, and mean meniscal extrusion 3.04mm. Post operatively, three patients required meniscal repair and a single patient partial menisectomy of graft. Two patients underwent arthroscopic arthrolysis following MAT. Conclusions. This series highlights the multifactorial profile of the meniscal deficient knee and the role of MAT as a safe and reliable technique in the staged and comprehensive biologic treatment available to minimise symptoms and maximise outcomes

For meniscal allograft transplantation, cell viability and metabolic activity are desirable. The various modalities of preserving the menisci described in the literature include, deep freezing, gluteraldehyde, lyophillisation and cryopreservation. Since formalin in low concentrations is a proven and inexpensive method of tissue preservstion, we attempted to analyse the viability of fibrochondrocytes in the meniscal tissue preserved in three different concentrations of formalin. Twenty-four rabbit menisci were assessed, three groups of 6 menisci each were preserved in 0.25%, 1%, 5% formalin for a period of three weeks; fourth group of 6 fresh menisci were used as controls. The uptake of Na235SO4 and LDH (lactate de-hydrogenase) were analysed for indirect evidence of cell viability. Menisci preserved in 0.25% of formaldehyde showed statistically similar Na235SO4 uptake and LDH activity as the controls; reflecting a similarity in the level of cell viability and metabolic activity. The menisci preserved in 1% and 5% formaldehyde solution showed a decreased radioactive uptake as well as LDH activity

Purpose. to evaluate the radial displacement of meniscal allograft transplants (MATs) in patients operated with an open technique vs. an arthroscopic technique at 1 year postoperatively. Radial displacement or extrusion of the graft is frequently observed after meniscus transplantation. The hypothesis is that arthroscopically inserted MATs extrude less than open MATs and therefore have a more intra-articular position than open surgery transplants. Materials and Methods. 39 patients were included in the study: the first group of open surgery transplants consisted of 16 patients (10 lateral, 6 medial). The second group of arthroscopic transplants consisted of 21 patients (14 lateral, 7 medial). MR-images were taken one year post-surgery. The displacement, evaluated on 1,5T MR coronal images, was defined as the distance between the tibial plateau and the outer edge of the meniscus. Results. The radial displacement of lateral open surgery transplants (mean = 4,04 mm; SD = 1,46) is significantly larger (p < 0,05) than the displacement of arthroscopically implanted MATs (mean = 3,38 mm; SD = 0,85). The external displacement of medial open surgery transplants (mean = 4,71 mm; SD = 0,97) is significantly larger (p < 0,05) than the displacement of arthroscopically implanted MATs (mean = 2,36 mm; SD = 0,89). Conclusion. Graft position is influenced by the surgical technique; the radial displacement of arthroscopically implanted MATs is, both lateral and medial, significantly less than meniscal transplants implanted by open surgery. The clinical relevance remains to be determined

INTRODUCTION. Meniscal tears are very common and treated surgically by suturing or partial or total meniscectomy. After meniscectomy, the tibiofemoral contact area is decreased whih leads to higher contact stresses associated with clinical symproms and a faster progression of tibiofemoral osteoarthritis. Besides meniscus allograft transplantation, artificial implants have been developed to replace the menisci after meniscectomy. AIM. We investigated the short- and medium-term clinical results and survivorship of two artificial meniscus implants used as a treatment for post-meniscectomy pain in young to middle-aged patients: the anchored polyurethane degradable Actifit® (2007–2013) and the non-anchored polycarbonate-urethane NUSurface® meniscal implants (2011–2013). PATIENTS AND METHODS. Sixty-seven Actifit were implanted in 67 patients with a mean age of 30.5 years (12 to 50) as a lateral meniscus replacement in 24 cases and medial in 43. Forty-one NUSurface were implanted as a medial meniscus replacement in 35 patients aged 31 to 61 at surgery. Clinical scores (KOOS, Lysholm, IKDC, VAS and EQ-5D) and MRI were obtained preoperatively and at 1, 2 and 5 years (if applicable) postoperatively. Complications and reinterventions were noted and cumulative implant survivorship computed. RESULTS. Seventeen Actifit had been removed at a mean of 22 months postop for persisting pain and/or extrusion of the implant on MRI. Three were converted to a Total Knee Arthroplasty (TKA), 7 replaced by a meniscal allograft and 7 were removed. The cumulative survivorship was 63.6% at 6 years. Forty-six patients with the Actifit in situ had a significant improvement of all clinical scores compared to preoperative scores (p<0.05) and were satisfied with the result. In the NUSurface group, 19 of the 41 implanted menisci had been removed at 2 to 26 months follow-up. Reasons for failure were radial tear or rupture of the meniscus in 7 cases, dislocation with or without tear in 4, synovitis and hydrops in 2 possibly related to synovial reaction to polymer particles, medial pressure caused by a too large size in 3 and persistent pain or OA evolution in 3. In 5 patients the implant was replaced by the same type artificial meniscus, unsuccessfully in 3. Besides, complications occurred in 32 patients including inflammation, effusion and squeaking. Nevertheless the KOOS, IKDC and VAS for pain were significantly improved at 12 months postoperatively (p<0.001). DISCUSSION. Short-term clinical evaluation of artificial meniscal replacement after meniscectomy showed an initial improvement of pain and knee function. However, both in the anchored degradable polyurethane meniscal implant group as in the non-anchored polycarbonate-urethane implant group the number of short-term failures was high and associated with important morbidity. The hard, non-degradable polycarbonate-urethane meniscal implant was torn or worn in 7 cases within 2 years postop. Three patients had synovial reactions possibly related to particulate debris. In conclusion, the currently available artificial meniscal transplants have a too high short-term failure rate to be advocated for widespread clinical use

Experimental and clinical studies have documented that meniscal allografts show capsular ingrowth in meniscectomized knees. However it remains to be established whether meniscal allograft transplantation can prevent degenerative changes after total meniscectomy. In this study, functional changes in articular cartilage after meniscus transplantation in rabbits were evaluated quantitatively. Thirty rabbits were divided into five groups. Group A and Group C were subjected to meniscectomy. Group B and Group D underwent meniscal transplantation immediately after meniscectomy. Group E had delayed transplantation 6 weeks after meniscectomy. Six nonoperated knees served as controls. Using image analysis with QwinPro software ffunctional changes of articular cartilage were examined 6 weeks (Groups A, B) and 1 year (Groups C, D, E, controls) after surgery by measuring the lactate dehydrogenase (LDH) activity in chondrocytes as a measure of their vitality and the proteoglycan content of the extracellular matrix as a measure of its quality. All experimental groups demonstrated a significant decrease in proteoglycan content of the cartilage as compared with the control group. At 6 weeks and 1 year follow-up, no significant differences were found between the postmeniscectomy group and immediate transplant group. The delayed transplant group showed a significantly decreased proteoglycan content as compared with the postmeniscectomy group. Compared to the control group, no significant differences in cellular LDH activity were found in the postmeniscectomy group and immediate transplant group at 6 weeks and 1 year. However, delayed transplantation caused diminished vitality of chondrocytes. No significant differences were found between the postmeniscectomy group and immediate transplant group at 6 weeks and 1 year. The delayed transplant group showed a significant decrease in LDH activity as compared with the postmeniscectomy group. It can be concluded that immediate meniscal transplantation in rabbits did not significantly reduce degenerative changes of articular cartilage whereas delayed transplantation leads to even more degenerative changes than meniscectomy

Osteoarthritis is the end stage of a gradual process of degradation of the cartilage and secondary responses in other tissues within a joint after many years of use. It is common in the knee joints in elderly. The surgical treatments for OA are often symptomatic, such as arthroplasty and HTO. Traumas to the knee, especially in combination with other injuries such as ACL rupture or meniscal tears, can lead to a speedy process and premature OA. The osteoarthritic patient often experiences a gradual on set of symptoms such as pain and swelling on weight bearing, catching and locking and in late stage nightly pains, leading to a very limited lifestyle. If it is possible to treat the OA at an early stage and thus hindering the destruction of the joint, much is won for the patient. Autologous chondrocyte transplantation (ACT) is a treatment for focal chondral and osteochondral lesions in the knee joint. The technique has also been used on patients with early stages of OA in knee, including multiple lesions, kissing lesions, lesions in combination with malalignment, instability and total mensicectomy. When treating these patients it is important to not only focus on the cartilage lesions but also on other pathology. A high tibial osteotomy should be considered, especially if there is a malalignment, but also as an unloading procedure if the lesion is large or if there are bipolar kissing lesions. If the patient has had total or subtotal meniscectomy meniscal allograft transplantation may be indicated. Ligamentous instability from a ruptured ACL for example must also be treated. All these procedures can be done prior to or after the ACT, but mostly concomitant with the ACT. As the patients have often been symptomatic for a long time and the greater surgical trauma with a concomitant procedure, it is harder to regain knee function after the surgery. Close contact between the patient, the doctor and the physical therapist is imperative, so measures can be taken if the patient does not progress accordingly. Young patients with early OA are hard cases. These patients often have a high demand on knee function and have had a high level of activity but are disabled by their symptoms. When treating these patients with ACT it is important to assess and treat all pathology that may jeopardize a good outcome

Objectives

Meniscal injuries are often associated with an active lifestyle. The damage of meniscal tissue puts young patients at higher risk of undergoing meniscal surgery and, therefore, at higher risk of osteoarthritis. In this study, we undertook proof-of-concept research to develop a cellularized human meniscus by using 3D bioprinting technology.